Water-soluble fibers having post-processing modification and articles containing the same

Abstract

Disclosed are methods for treating fibers containing polymers containing at least one vinyl acetate or vinyl alcohol moiety, and the resulting fibers or products containing the resulting fibers. In exemplary embodiments, the method for treating fibers includes contacting the surface of the polymer-containing fiber with a modifying agent to chemically modify at least a portion of the polymer in a region of the fiber including at least the surface of the fiber, forming a modified fiber. The present disclosure generally relates to water-soluble fibers. More specifically, the present disclosure relates to water-soluble fibers comprising modified polymers containing vinyl acetate and / or vinyl alcohol moieties after fiber formation by chemically modifying the vinyl alcohol moieties in the polymer.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit of U.S. Provisional Application No. 63 / 074,716, filed on 4 September 2020, which is expressly incorporated herein by reference in its entirety.

[0002] field This disclosure generally relates to water-soluble fibers. More specifically, this disclosure relates to water-soluble fibers comprising a modified polymer containing a vinyl acetate moiety and / or a vinyl alcohol moiety after fiber formation, by chemically modifying the vinyl alcohol moiety in the polymer.

[0003] background Nonwoven webs are traditionally used in many single-use consumer products, including bandages, diaper components, feminine care and adult incontinence products, as well as single-use wipes in industrial, medical, hygiene, and personal / baby care applications. The traditional chemicals used in such products, such as viscose, polypropylene, or cotton fibers, are generally non-sustainable, non-biodegradable, and potential contributors to microplastics, often improperly disposed of by being flushed down the toilet and entering wastewater treatment and sewage facilities. Known wipes must be disposed of in the trash can, which can be neither hygienic nor convenient for the user. The improper disposal of these items can result in clogged plumbing in homes and the formation of "fatbergs," or aggregates of solidified grease and cooking fat and disposable wipes, in residential and urban wastewater systems, which can contribute to marine microplastics, and a change in consumer behavior may be necessary.

[0004] The solubility profile and mechanism of water-soluble articles (e.g., hot vs. cold solubility, readily soluble vs. delayed solubility, or extended release) may need to be adjusted based on the article's final use. For articles containing water-soluble fibers, the solubility profile and mechanism can be varied by selecting fiber-forming materials with various chemical modifications, such as copolymerization. However, the chemical modification of the fiber-forming material also affects its ability to form fibers. Therefore, fibers formed from a specific polymer with a desired chemical modification to provide fibers with a desired solubility profile may not be available because the fiber-forming material may not withstand the fiber-making process. Thus, it is considered advantageous to provide a method for modifying the solubility profile of fibers after fiber formation in order to obtain solubility profiles that are not normally available.

[0005] Furthermore, the solubility profile, bondability, and other properties of the fibers or water-soluble articles prepared therefrom, such as mechanical properties and chemical compatibility, can be designed to suit specific end applications. Thus, it is considered advantageous to provide methods for improving bondability, extending the chemical compatibility and / or other properties of fibers after fiber formation, and / or maintaining or modifying the solubility profile of nonwoven webs before assembly into composites for inventory management. Extended chemical compatibility is used in applications for packaging and distribution. The ability to post-process the chemical composition of fibers, and therefore the fiber solubility process, is considered advantageous in enabling the availability of various fiber types starting from one or a handful of fiber types. Post-manufacturing fiber modification offers many advantages, including processability, modification of processing, and / or flexibility of composition.

[0006] Brief explanation of the drawing To further facilitate understanding of this disclosure, 24 figures are attached to this specification. [Brief explanation of the drawing]

[0007] [Figure 1]Figures 1A to 1D show cross-sections of various fiber shapes according to exemplary embodiments, where the lines indicate the fiber diameter.

[0008] [Figure 2] Figure 2A shows a cross-section of a round fiber characterized by a core-sheath structure according to an exemplary embodiment, where the polymer of the sheath (shell) 202 has a higher degree of chemical modification or modification than the polymer of the core 201.

[0009] Figure 2B shows a cross-section of a round fiber characterized by an increasing gradient of polymer modification from the internal region 301 to the surface region 302, according to an exemplary embodiment.

[0010] Figure 2C shows a cross-section of a round fiber characterized by having the same or equivalent degree of modification of the polymer across the cross-section, according to an exemplary embodiment.

[0011] [Figure 3] Figure 3 shows a cross-section of a round fiber according to an exemplary embodiment, having a first region, e.g., a core region 401, a second region, e.g., a sheath (shell) region 402, and at least one third region, e.g., two intermediate regions 403a and 403b positioned between the first and second regions, wherein the cross-section of the fiber is characterized by an increasing gradient of polymer modification from the first region to the second region.

[0012] [Figure 4] Figure 4A is a micrograph of a nonwoven web of the present disclosure having a softness grade of 1, according to an exemplary embodiment.

[0013] Figure 4B is a micrograph of a nonwoven web of the present disclosure having a softness grade of 5, according to an exemplary embodiment.

[0014] [Figure 5] Figure 5 shows an example of a nonwoven web according to an exemplary embodiment, in which the outer surfaces of the web are labeled 100 and 101.

[0015] [Figure 6] Figure 6 shows the ATR-FTIR results of a breathable nonwoven web containing multiple fibers (fiber A) with and without chemical modification with glutaric anhydride in THF, according to an exemplary embodiment, at 60°C for 5 hours.

[0016] [Figure 7] Figure 7 shows the ATR-FTIR results of a breathable nonwoven web containing multiple fibers (fiber A) with and without chemical modification with maleic anhydride in THF, according to an exemplary embodiment, at 60°C for 5 hours.

[0017] [Figure 8] Figure 8 shows the ATR-FTIR results of a breathable nonwoven web containing multiple fibers (fiber A) with and without chemical modification with phthalic anhydride in THF, according to an exemplary embodiment, at 60°C for 5 hours.

[0018] [Figure 9] Figure 9 shows the ATR-FTIR results for several fibers (fiber E) in THF at 60°C for 5 hours, both with and without chemical modification with maleic anhydride, according to an exemplary embodiment.

[0019] [Figure 10] Figure 10 shows the breakdown time (seconds) of a breathable nonwoven web having multiple fibers (fiber A) with and without chemical modification with an anhydride such as maleic anhydride, glutaric anhydride, or phthalic anhydride, according to an exemplary embodiment, at 60°C for 5 hours in THF.

[0020] [Figure 11] Figure 11 shows the fracture time (seconds) of a nonwoven web having multiple fibers (fiber A) in DCM with and without chemical modification by maleic anhydride, according to an exemplary embodiment, at room temperature for 5 hours.

[0021] [Figure 12] Figure 12 shows the tensile strength of a breathable nonwoven web having multiple fibers (fiber A) with and without chemical modification with anhydrides such as maleic anhydride, glutaric anhydride, or phthalic anhydride, in THF at 60°C for 5 hours, according to an exemplary embodiment.

[0022] [Figure 13] Figure 13 shows the tensile strength of a nonwoven web having multiple fibers (fiber A) in DCM with and without chemical modification with maleic anhydride, according to an exemplary embodiment, at room temperature for 5 hours.

[0023] [Figure 14] Figure 14 shows the glycerin retention capacity (percentage of retention rate) of a breathable nonwoven web having multiple fibers (fiber A) with and without chemical modification with anhydrides such as maleic anhydride, glutaric anhydride, or phthalic anhydride, according to an exemplary embodiment, in THF at 60°C for 5 hours, with an initial glycerin load of 50%.

[0024] [Figure 15] Figure 15 shows the glycerin retention capacity (percentage of retention rate) of a nonwoven web having multiple fibers (fiber A) in DCM with and without chemical modification with maleic anhydride, according to an exemplary embodiment, at room temperature for 5 hours, with an initial glycerin load of 50%.

[0025] [Figure 16] Figure 16 shows the glycerin retention capacity (percentage of retention rate) of a breathable nonwoven web having multiple fibers (fiber A) with and without chemical modification with anhydrides such as maleic anhydride, glutaric anhydride, or phthalic anhydride, according to an exemplary embodiment, in THF at 60°C for 5 hours, with an initial glycerin load of 180%.

[0026] [Figure 17] Figure 17 shows the glycerin retention capacity (percentage of retention rate) of a nonwoven web having multiple fibers (fiber A) in DCM with and without chemical modification with maleic anhydride, according to an exemplary embodiment, at room temperature for 5 hours, with an initial glycerin load of 180%.

[0027] [Figure 18] Figure 18 shows the ATR-FTIR results for the interior ("inner region") and surface ("outer region") of an exemplary block containing a copolymer of vinyl acetate and vinyl alcohol, with and without chemical modification by maleic anhydride in THF at 60°C for 5 hours, according to an exemplary embodiment. [Modes for carrying out the invention]

[0028] Detailed explanation This specification provides a method for treating a fiber to chemically modify the polymer constituting the fiber by contacting the fiber or its surface with a modifying agent to chemically modify at least a portion of the polymer with the modifying agent in a region of the fiber or its surface, thereby forming a modified fiber. This specification also provides a method for treating a fiber by mixing a fiber containing a polymer, a modifying agent, and optionally a solvent for the modifying agent to chemically modify at least a portion of the polymer with the modifying agent and form a modified fiber. In embodiments, the fiber is insoluble in the solvent for the duration of contact of the fiber with the solvent. The methods of this disclosure can advantageously provide fibers having chemical modification or increased chemical modification of the polymer constituting the fiber, fibers having a core-sheath structure in which the polymer in the sheath or surface region has a different amount of chemical modification (degree of modification) than the polymer in the core or internal region, and / or fibers having a gradient of chemical modification of the polymer constituting the fiber from the internal region to the surface region. Optionally, the polymer comprises at least one of a vinyl acetate portion or a vinyl alcohol portion. As used herein, “at least one vinyl acetate moiety or vinyl alcohol moiety” and “vinyl acetate moiety and / or vinyl alcohol moiety” describe exemplary polymers containing only a vinyl acetate moiety, only a vinyl alcohol moiety, or both a vinyl acetate moiety and a vinyl alcohol moiety. In this disclosure, the singular forms “a,” “an,” and “the” include plural subjects unless otherwise explicitly stated in the context. Thus, for example, a reference to “vinyl alcohol moiety” refers to one or more such structures and equivalents containing a vinyl alcohol moiety. For example, such a polymer may be a copolymer containing both a vinyl acetate moiety and a vinyl alcohol moiety, i.e., a copolymer of vinyl acetate and vinyl alcohol.

[0029] One aspect of the present disclosure provides a method for treating a fiber to chemically modify the polymer constituting the fiber by contacting the fiber or its surface with a modifying agent to chemically modify at least a portion of the polymer with the modifying agent in a region of the fiber or its surface, thereby forming a modified fiber. In an embodiment, contacting the fiber or its surface with a modifying agent includes mixing a fiber containing a polymer including a vinyl acetate portion and / or a vinyl alcohol portion, a modifying agent, and optionally a solvent for the modifying agent.

[0030] Another aspect of the present disclosure provides a modified fiber that is chemically modified with a modifying agent by the method of the present disclosure.

[0031] Another aspect of the present disclosure provides a fiber having a surface region and an internal region. The fiber comprises a modified polymer including a vinyl acetate portion and / or a vinyl alcohol portion. The fiber has a cross-section comprising an internal region containing a polymer having a first degree of modification and a surface region containing a polymer having a second degree of modification greater than the first degree of modification.

[0032] Another aspect of the present disclosure provides a fiber having a cross-section having a core-sheath structure. The fiber comprises a first region, e.g., a core region, comprising a polymer having a first degree of modification, and a second region, e.g., a sheath region, comprising a polymer having a second degree of modification. The second degree of modification is different from, for example, greater than, the first degree of modification.

[0033] Another aspect of the present disclosure provides a method for processing a nonwoven web comprising a plurality of fibers. In an exemplary embodiment, each fiber comprises a polymer comprising a vinyl acetate portion and / or a vinyl alcohol portion. The method includes contacting at least a portion of the nonwoven web with a modifying agent so that a modified nonwoven web is provided by chemically modifying the polymer with the modifying agent in the region of each fiber within the nonwoven web.

[0034] Another aspect of the present disclosure provides a modified nonwoven web in which the internal polymer is chemically modified with a modifier by the method of the present disclosure.

[0035] Another aspect of the present disclosure provides a nonwoven web containing the modified fibers of the present disclosure.

[0036] Another aspect of the present disclosure provides a multilayer nonwoven web comprising a first layer comprising a nonwoven web processed according to the method of the present disclosure or a nonwoven web comprising fibers of the present disclosure.

[0037] Another aspect of the present disclosure provides a pouch comprising a nonwoven web according to the present disclosure, in the form of a pouch defining an internal pouch volume.

[0038] Another aspect of the present disclosure provides an sealing article comprising a nonwoven web of the present disclosure.

[0039] Another aspect of this disclosure provides a flushable article comprising a nonwoven web of the disclosure.

[0040] Another aspect of the present disclosure provides a wearable absorbent article comprising an absorbent core having a wearer side and an outer side, and a liquid-receiving layer, wherein the liquid-receiving layer comprises a nonwoven web of the present disclosure.

[0041] Further embodiments and advantages will become apparent to those skilled in the art from consideration of the following detailed description. While fibers, nonwoven webs, pouches, articles and methods for producing them can take on various forms, the following description herein includes specific embodiments, with the understanding that this disclosure is illustrative, and is not intended to limit the invention to the specific embodiments described herein.

[0042] In embodiments, the fibers of the disclosure are water-soluble before treatment with a modifying agent and remain water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are cold-water-soluble before treatment with a modifying agent and hot-water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are cold-water-soluble before treatment with a modifying agent, and at least a portion of the outer surface of the fibers becomes hot-water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are hot-water-soluble before treatment with a modifying agent and cold-water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are hot-water-soluble before treatment with a modifying agent, and at least a portion of the outer surface of the fibers becomes cold-water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are hot-water-soluble before treatment with a modifying agent, and at least a portion of the outer surface of the fibers becomes cold-water-soluble after treatment with a modifying agent. In embodiments, the fibers of the disclosure are cold-water-soluble before treatment with a modifying agent and remain cold-water-soluble after treatment with a modifying agent. In embodiments, the fibers are not water-soluble before treatment with a modifying agent, and the fibers are water-soluble after treatment with a modifying agent. In this embodiment, the fibers are not water-soluble after being mixed with the modifying agent.

[0043] The methods and fibers of the present disclosure can provide one or more advantages, including, but not limited to, controlling the microstructure of the fiber, modifying the solubility profile and / or mechanism of the fiber, increasing the chemical compatibility of the fiber with chemical agents, increasing the absorbency of the fiber, increasing and / or controlling the loading of activators into the fiber, controlling the release of compositions or active substances from within the fiber, increasing interfiber aggregation via intermolecular forces, and creating crosslinking sites via covalent bond formation, and improving the processability of the fiber and the nonwoven web formed therefrom (e.g., enabling nonwoven bonding using aerated bonds, improving tensile strength, providing fixation sites for additional functional groups, and enabling induced delivery of activators).

[0044] Unless otherwise specified, the term "degree of hydrolysis" is understood as the percentage (e.g., molar percentage) of the hydrolyzed portion of all hydrolyzable portions originally present in the polymer. For example, in a polymer containing at least one vinyl acetate moiety or vinyl alcohol moiety, partial substitution of the ester groups of the vinyl acetate moiety by hydroxyl groups occurs during hydrolysis, with the vinyl acetate moiety becoming the vinyl alcohol moiety. The degree of hydrolysis of polyvinyl acetate homopolymer is considered to be zero, while the degree of hydrolysis of polyvinyl alcohol homopolymer is 100%. The degree of hydrolysis of vinyl acetate and vinyl alcohol copolymers is equal to the percentage of the vinyl alcohol portion of the total vinyl acetate and vinyl alcohol moieties, and is between zero and 100%.

[0045] As used herein, and unless otherwise specified, the term “degree of modification” as used herein with respect to chemical modification refers to the amount of chemical modification provided to the polymer backbone of the fibers described herein. For example, a polyvinyl alcohol copolymer backbone may contain (partial) vinyl alcohol monomer units and (partial) vinyl acetate monomer units depending on the degree of hydrolysis, and the degree of modification of the polyvinyl alcohol is 2 mol% if the polyvinyl alcohol is modified by 2 mol% with monomethyl maleate, based on the total amount of vinyl alcohol monomer units and vinyl acetate monomer units. As used herein, and unless otherwise specified, a copolymer having two or more monomer units in the backbone is not considered a modified polymer unless the backbone units are chemically modified after fiber formation, as described herein. For example, a polyvinyl alcohol copolymer containing vinyl alcohol monomer units, vinyl acetate monomer units, and monomethyl maleate monomer units, where the monomethyl maleate monomer units constitute 2 mol% of the total backbone monomer units, is not considered to have a degree of modification of 2 mol%. However, such copolymers can be chemically modified, for example, with 3 mol% monomethyl maleate to provide copolymers containing 2 mol% monomethyl maleate backbone units with 3 mol% monomethyl maleate modification. As used herein, unless otherwise specified, the terms “chemical modification” and “to be chemically modified” refer to modification of the polymer backbone of the fiber, chemical modification does not involve hydrolysis of the polymer, and chemical modification does not increase the amount of backbone monomer units.For example, the polyvinyl alcohol copolymer backbone may contain vinyl alcohol monomer units and vinyl acetate monomer units depending on the degree of hydrolysis. When polyvinyl alcohol is said to be chemically modified as herein, the total amount of vinyl alcohol monomer units and vinyl acetate monomer units decreases by the amount of chemical modification (degree of modification) compared to an unmodified or non-modified polymer, because the vinyl alcohol monomer units and / or vinyl acetate monomer units are converted into modified monomer units. The fiber polymers disclosed herein may have a degree of modification before further chemical modification of the fiber polymer, and therefore the total degree of modification is considered to be the degree of modification before further chemical modification of the fiber polymer plus the degree of modification resulting from the modifying agent disclosed herein. In some embodiments, the hydroxyl (-OH) groups in the vinyl alcohol portion react with the modifying agent, and the polymer backbone is chemically bonded to the portion of the modifying agent.

[0046] Where used herein, unless otherwise specified, the term “water-soluble” means any nonwoven web or article containing the same having a dissolution time of 300 seconds or less at a specified temperature, as determined according to the method for testing dissolution and disintegration times as shown herein (MSTM-205), or any fiber having a complete dissolution time of less than 30 seconds at a specified temperature, as determined according to the method for determining the solubility of a single fiber disclosed herein. For example, the solubility parameter may be a property of a nonwoven web having a thickness of 6 mil (about 152 μm) or an article made therefrom. The dissolution time of the nonwoven web may be 200 seconds or less, 100 seconds or less, 60 seconds or less, or 30 seconds or less at temperatures of about 100°C, about 90°C, about 80°C, about 70°C, about 60°C, about 50°C, about 40°C, about 20°C, or about 10°C, as needed. In embodiments where the dissolution temperature is not specified, water-soluble nonwoven webs have a dissolution time of 300 seconds or less at temperatures of about 100°C or less. Fibers may have a complete dissolution time of 30 seconds or less at temperatures of about 100°C, about 90°C, about 80°C, about 70°C, about 60°C, about 50°C, about 40°C, about 20°C, or about 10°C. As used herein, if a fiber has a complete dissolution time of more than 30 seconds at a specified temperature according to the method for determining the single fiber solubility disclosed herein, the fiber is “insoluble,” “water-insoluble,” “non-water-soluble,” or “water-insoluble.” In embodiments where the complete dissolution temperature is not specified, water-soluble fibers have a complete dissolution time of 30 seconds or less at temperatures of about 100°C or less, and water-insoluble fibers have a complete dissolution time of more than 30 seconds at temperatures of about 100°C or less. As used herein, unless otherwise specified, the term “coldly water-soluble” refers to any nonwoven web having a dissolution time of 300 seconds or less at 10°C, as determined according to MSTM-205. For example, the dissolution time may be 200 seconds or less, 100 seconds or less, 60 seconds or less, or 30 seconds at 10°C, as needed.As used herein, unless otherwise specified, the term “coldly water-soluble” in relation to fibers means fibers having a complete dissolution time of 30 seconds or less at a temperature of 10°C or less, according to the method for determining the solubility of a single fiber disclosed herein.

[0047] As used herein, unless otherwise specified, the term “water-dispersible” means a nonwoven web or article containing the same that, upon immersion in water at a particular temperature, physically separates into smaller components. The smaller fragments may or may not be visible to the naked eye, may or may not remain suspended in water, and may or may not ultimately dissolve. In embodiments where the dispersion temperature is not specified, the nonwoven web or pouch disintegrates in 300 seconds or less at a temperature of about 100°C or less, according to MSTM-205. For example, the disintegration time may be 200 seconds or less, 100 seconds or less, 60 seconds or less, or 30 seconds or less at temperatures of about 80°C, about 70°C, about 60°C, about 50°C, about 40°C, about 20°C, or about 10°C, as needed, according to MSTM-205. For example, such dispersion parameters may be properties of a nonwoven web or article made therefrom having a thickness of 6 mil (about 152 μm).

[0048] As used herein, the term “flushable” means articles that are dispersible in an aqueductible environment, such as a sewage system, such as nonwoven webs or pouches, such that, as a result of the disposal of the webs or pouches, such articles do not remain in or accumulate over time in the piping of a water supply and drainage system, causing blockage of such piping. The INDA / EDANA standard for flushability requires that more than 95% of the starting material must pass through a 12.5 mm sieve after a 60-minute sloshbox test using 28 RPM (revolutions per minute) and an 18° inclination angle. The flushability test described herein provides a more rigorous flushability test. A commercially available nonwoven web in the form of a flushable wipe, referred herein as Commercial Wipe A, is guaranteed to be flushable and has a disintegration time of 20 seconds as measured by the flushability test described herein. Therefore, as used herein, unless otherwise specified, the term “flushable” means an article having a percentage disintegration that meets or exceeds the percentage disintegration of commercial wipe A (20%) as measured by the flushability test provided herein, such as a nonwoven web or pouch. Flushable nonwoven webs and articles containing them have the advantage of being more processable in recycling methods, or for example, being simply flushed into a municipal sewage treatment system for purification, and having no need for landfill, incineration, or other disposal after use of the web, structure, or pouch.

[0049] As used herein, unless otherwise specified, the term “nonwoven web” means a web or sheet consisting of, or essentially composed of, fibers arranged (e.g., by carding) and bonded together. Thus, the term “nonwoven web” can be considered a simplified term for a nonwoven fiber-based web. Furthermore, as used herein, “nonwoven web” includes any structure including a nonwoven web or sheet, for example, a nonwoven web or sheet having a film laminated to its surface. Methods for preparing nonwoven webs from fibers are well known in the art and are described, for example, in the Nonwoven Fabrics Handbook, prepared by Ian Butler, edited by Subhash Batra et al., Printing by Design, 1999, which is incorporated herein by reference in its entirety. As used herein, unless otherwise specified, the term “film” means a continuous film or sheet prepared, for example, by casting or extrusion.

[0050] When used herein, “contains” means that various components, ingredients, or steps can be used together to carry out the disclosure. Thus, the term “contains” encompasses the more restrictive terms “essentially from” and “consisting of.” The compositions may contain, essentially from, or consist of any of the necessary and optional elements disclosed herein. For example, a thermoformed packet may “essentially consist from” a nonwoven web as described herein for the use of its thermoformable properties, while including a non-thermoformable film or nonwoven web (e.g., a lid portion) and optional markings on the film, such as by inkjet printing. The inventions disclosed exemplary herein may be suitably carried out in the absence of any element or step not specifically disclosed herein.

[0051] All percentages, parts, and ratios referred to herein are, where applicable, based on the total dry weight of the nonwoven web or film composition or the total weight of the packet contents composition, and all measurements are taken at approximately 25°C unless otherwise specified. All such weights are based on activity levels and therefore do not include carriers or by-products that may be present in commercially available materials unless otherwise specified.

[0052] All ranges described herein include all possible subsets of a range and any combination of such subset ranges. By default, unless otherwise stated, a range includes the stated endpoint. Where a range of values ​​is presented, it is understood that each value between the upper and lower bounds of that range, and any other stated or intervening values ​​of that stated range, are included within this disclosure. The upper and lower bounds of these smaller ranges may be independently included in the smaller range and are also included within this disclosure, subject to any particularly excluded limits of the stated range. Where a stated range includes one or both of the bounds, the range excluding one or both of the included bounds is also intended to be part of this disclosure.

[0053] For example, with respect to any numerical value described herein as part of a parameter of the subject matter described or as part of a range associated with the subject matter described, it is clearly intended that alternatives forming part of the description are functionally equivalent ranges that enclose a particular numerical value (for example, for a dimension disclosed as "40 mm", the intended alternative embodiment is "about 40 mm").

[0054] As used herein, the terms packet and pouch should be considered interchangeable. In certain embodiments, the terms packet and pouch are used to refer to containers made using nonwoven webs and / or films, and to fully sealed containers, preferably having a sealed material therein, for example, in the form of a measuring dose delivery system. Sealed pouches may be made from any preferred method, including processes and features such as heat sealing, solvent welding, and adhesive sealing (e.g., by using a water-soluble adhesive).

[0055] As used herein, unless otherwise specified, the terms “wt.%” and “wt%” are intended to mean the composition of a particular element in parts by weight of the entire article or composition referred to, for example, parts by weight of a nonwoven web or film or laminate structure including residual moisture (where applicable) in the nonwoven web or film, or parts by weight of a composition (where applicable) enclosed in a pouch.

[0056] As used herein, unless otherwise specified, the term “PHR” (“phr”) is intended to mean the composition of a specific element per 100 parts of the polymer-containing article referred to, for example, a water-soluble film, fiber or nonwoven web, or the water-soluble polymer (whether PVOH or any other polymer, unless otherwise specified) in the solution used to produce the fiber or film.

[0057] Nonwoven webs, pouches and related articles, as well as methods of manufacture and use, are intended to include embodiments that, unless otherwise stated, include one or more of the additional elements, features and steps (including those shown in the examples and figures) described below as necessary.

[0058] Fiber-forming materials

[0059] Generally, the fibers of this disclosure may comprise a single fiber-forming material or a combination (i.e., a blend) of fiber-forming materials. A single fiber may comprise one or more water-soluble fiber-forming materials, one or more water-insoluble fiber-forming materials, or a combination of water-soluble and water-insoluble fiber-forming materials. Generally, the fibers of this disclosure may comprise synthetic fiber-forming materials, natural fiber-forming materials, plant-based fiber-forming materials, bio-based fiber-forming materials, biodegradable fiber-forming materials, compostable fiber-forming materials, or combinations thereof. Plant-based fiber-forming materials may be naturally occurring (e.g., cotton) or reconstituted (e.g., bamboo).

[0060] Generally, the fibers of this disclosure include fiber-forming materials containing functional groups that can be chemically modified before contact with a modifying agent. As used herein, chemically modified functional groups generally include, but are not limited to, any functional groups that can undergo esterification, amidation, amination, carboxylation, nitration, acyloin condensation, allylation, acetylation, imidation, halogenation, sulfonation, alkylation, acetalization, enolation, nitrosation, and silane coupling. Suitable polymers containing chemically modifiable functional groups include polyvinyl acetate, polyvinyl propionate, polyvinyl alcohol polymer, poly(N-vinylacetamide) polymer, polyvinyl butyral polymer, poly(butyl acrylate) polymer, poly(butyl methacrylate) polymer, cellulose acetate polymer, polyacrylonitrile polymer, poly(N-isopropylacrylamide) polymer, poly(N,N-diethylacrylamide) polymer, poly(N,N-dimethylacrylamide) polymer, poly(methyl vinyl ether) polymer, poly(N,N-dimethylaminoethyl methacrylate) polymer, poly(N-vinylformamide) polymer, poly(N-vinylcaprolactam) polymer, polyvinylpyrrolidone polymer, polylactic acid, and combinations thereof.

[0061] In embodiments, the fibers of the present disclosure may include polymers comprising at least one vinyl acetate moiety or vinyl alcohol moiety. In some embodiments, suitable examples of polymers comprising at least one vinyl acetate moiety or vinyl alcohol moiety include, but are not limited to, polyvinyl alcohol homopolymers, polyvinyl acetate homopolymers, polyvinyl alcohol copolymers, modified polyvinyl alcohol copolymers, and combinations thereof. For example, polyvinyl alcohol copolymers are, in some embodiments, copolymers of vinyl acetate and vinyl alcohol. For example, in some embodiments, modified polyvinyl alcohol copolymers include anionic modified copolymers, which may be copolymers of vinyl acetate and vinyl alcohol further comprising additional groups such as carboxylates, sulfonates, or combinations thereof. Also, such polymers comprising at least one vinyl acetate moiety or vinyl alcohol moiety may include additional polymers, for example, in a blend. In some embodiments, the hydroxyl (-OH) group in the vinyl alcohol moiety reacts with a modifier for chemical modification of the polymer.

[0062] Polyvinyl alcohol is a synthetic polymer generally prepared by the alcoholic decomposition of polyvinyl acetate, typically through hydrolysis or saponification. Completely hydrolyzed PVOH, where virtually all acetate groups are converted to alcohol groups, is a strongly hydrogen-bonded, highly crystalline polymer that dissolves only in hot water above approximately 140°F (about 60°C). If a sufficient number of acetate groups remain after the hydrolysis of polyvinyl acetate, i.e., the PVOH polymer is partially hydrolyzed, the polymer is less hydrogen-bonded and less crystalline, generally soluble in cold water below approximately 50°F (about 10°C). Thus, the partially hydrolyzed polymer is a vinyl alcohol-vinyl acetate copolymer, also known as PVOH (polyvinyl alcohol) copolymer, but is generally referred to as "polyvinyl alcohol (PVOH)" or "PVOH polymer." Simply put, the term "PVOH polymer" as used herein is understood to encompass homopolymers, copolymers, and modified copolymers containing a vinyl alcohol moiety, e.g., 50% or higher. As used herein, the term “PVOH fiber” is understood to include fibers comprising homopolymers, copolymers, and modified copolymers, which include vinyl alcohol moieties, e.g., 50% or more of vinyl alcohol moieties; and fibers comprising such polymers chemically modified with a modifying agent. Chemically modified fibers may contain no vinyl alcohol units or less than 50% vinyl alcohol units.

[0063] The fibers described herein may include polyvinyl acetate, one or more polyvinyl alcohol (PVOH) homopolymers, one or more polyvinyl alcohol copolymers, or combinations thereof. As used herein, the term “homopolymer” generally includes polymers having a single type of monomer repeating units (e.g., polymer chains consisting of or substantially thereof of single monomer repeating units). In the specific case of PVOH, the term “PVOH polymer” as an example of a polymer for chemical modification includes copolymers consisting of a distribution of vinyl alcohol monomer units and vinyl acetate monomer units, depending on the degree of hydrolysis (e.g., polymer chains consisting of or substantially thereof of vinyl alcohol and vinyl acetate monomer units). In the limited case of 100% hydrolysis, the PVOH polymer may also include true homopolymers having only vinyl alcohol units. In some embodiments, the fibers and / or films of the disclosure include polyvinyl alcohol copolymers. In some embodiments, the fibers and / or films of the disclosure include thermosoluble polyvinyl alcohol copolymers.

[0064] In some embodiments, the polymer for chemical modification includes a polyvinyl alcohol copolymer or a higher polymer (e.g., a terpolymer) containing one or more monomers in addition to the vinyl acetate / vinyl alcohol group. Optionally, the additional monomer is neutral and provided by, for example, ethylene, propylene, N-vinylpyrrolidone, or other uncharged monomer species. Optionally, the additional monomer is cationic and provided by, for example, a positively charged monomer species. Optionally, the additional monomer is anionic. Thus, in some embodiments, the polyvinyl alcohol includes an anionic polyvinyl alcohol copolymer. The anionic polyvinyl alcohol copolymer may include a partially or completely hydrolyzed PVOH copolymer containing anionic monomer units, vinyl alcohol monomer units, and optionally vinyl acetate monomer units (i.e., when not completely hydrolyzed). In some embodiments, the PVOH copolymer may contain two or more types of anionic monomer units. A general class of anionic monomer units that can be used in PVOH copolymers includes vinyl sulfonate monomers and their esters, vinyl monocarboxylate monomers, their esters and anhydrides, dicarboxylic acid monomers having polymerizable double bonds, their esters and anhydrides, and vinyl polymerization units corresponding to any of the alkali metal salts mentioned above.Examples of suitable anionic monomer units include vinylacetic acid, maleic acid, monoalkyl maleic acid, dialkyl maleic acid, maleic anhydride, fumaric acid, monoalkyl fumaric acid, dialkyl fumaric acid, itaconic acid, monoalkyl itaconic acid, dialkyl itaconic acid, citraconic acid, monoalkyl citraconic acid, dialkyl citraconic acid, citraconic acid anhydride, mesaconic acid, monoalkyl mesaconic acid, dialkyl mesaconic acid, glutaconic acid, monoalkyl glutaconic acid, dialkyl glutaconic acid, glutaconic acid anhydride, alkyl acrylate, alkyl alcohol, vinyl sulfonic acid, allyl sulfonic acid, and ethylene sulfone. The vinyl polymerization units, which correspond to vinyl anionic monomers, include acids, 2-acrylamide-1-methylpropanesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 2-methylacrylamide-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, the aforementioned alkali metal salts (e.g., sodium, potassium, or other alkali metal salts), the aforementioned esters (e.g., methyl, ethyl, or other C1-C4 or C6 alkyl esters), and the aforementioned combinations (e.g., anionic monomers or numerous types of equivalent forms of the same anionic monomers). In some embodiments, the PVOH copolymer may contain two or more types of monomer units selected from neutral, anionic, and cationic monomer units.

[0065] The level of incorporation of one or more monomer units in the PVOH copolymer is not particularly limited. In embodiments, one or more monomer units are present in the PVOH copolymer in amounts ranging from about 1 mol% or 2 mol% to about 6 mol% or 10 mol% (e.g., at least 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 mol% and / or up to about 3.0, 4.0, 4.5, 5.0, 6.0, 8.0, or 10 mol%). In embodiments, the additional monomer units may be anionic monomer units, which are present in the PVOH copolymer in amounts ranging from about 1 mol% or 2 mol% to about 6 mol% or 10 mol% (for example, at least 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 mol%, and / or up to about 3.0, 4.0, 4.5, 5.0, 6.0, 8.0, or 10 mol%).

[0066] Polyvinyl alcohol can be subjected to changes in solubility properties. It is known to those skilled in the art that the acetate groups of vinyl acetate and vinyl alcohol copolymers (PVOH copolymers) are hydrolyzable by either acidic or alkaline hydrolysis. As the degree of hydrolysis increases, polymer compositions made from PVOH copolymers will have increased mechanical strength, but their solubility will decrease at lower temperatures (e.g., requiring hot water temperatures for dissolution). Therefore, exposure of PVOH copolymers to an alkaline environment (e.g., from laundry bleach additives) can convert the polymer from one that dissolves rapidly and completely in a given aqueous environment (e.g., cold water medium) to one that dissolves slowly and / or incompletely in an aqueous environment, potentially resulting in undissolved polymer residue at the end of a washing cycle.

[0067] For example, PVOH copolymers having pendant carboxyl groups, such as vinyl alcohol / hydrolyzed methyl acrylate sodium salt polymers, can form lactone rings between adjacent pendant carboxyl and alcohol groups, thus reducing the water solubility of the PVOH copolymer. In the presence of a strong base, the lactone ring can be opened over a process of several weeks under relatively warm (ambient) and high humidity conditions (e.g., via a lactone ring-opening reaction, the corresponding pendant carboxyl and alcohol groups are formed, increasing water solubility). Therefore, contrary to the effects observed in PVOH copolymers of vinyl acetate and vinyl alcohol, it is thought that such PVOH copolymer pendant carboxyl groups may become more soluble due to chemical interactions between the polymer and the alkaline composition in the pouch during storage.

[0068] Certain sulfonic acids and their derivatives having polymerizable vinyl bonds can copolymerize with vinyl acetate to yield cold-water-soluble PVOH polymers that are stable in the presence of strong bases. The base-catalyzed alcohol decomposition products of these copolymers used in water-soluble film formulations are rapidly soluble vinyl alcohol-sulfonate salt copolymers. While the sulfonate groups of the PVOH copolymer can revert to sulfonic acid groups in the presence of hydrogen ions, these sulfonic acid groups still contribute to the polymer's excellent cold-water solubility. In embodiments, the vinyl alcohol-sulfonate salt copolymers do not contain residual acetate groups (i.e., are completely hydrolyzed) and therefore cannot be further hydrolyzed by either acidic or alkaline hydrolysis. Generally, as the amount of comonomer increases, water solubility increases, and therefore, sufficient inclusion of sulfonate or sulfonic acid groups inhibits hydrogen bonding and crystallinity, enabling solubility in cold water. In the presence of acidic or basic species, copolymers are generally unaffected except for the sulfonate or sulfonic acid groups, which maintains excellent cold water solubility even in the presence of acidic or basic species. Examples of suitable sulfonic acid comonomers (and / or alkali metal salt derivatives thereof) include vinyl sulfonic acid, allyl sulfonic acid, ethylene sulfonic acid, 2-acrylamide-1-methylpropanesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 2-methacrylamide-2-methylpropanesulfonic acid, and 2-sulfoethyl acrylate, with the sodium salt of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) being a preferred comonomer.

[0069] The fiber-forming polymer can be a blend of polyvinyl alcohol polymers or other polymers. If the polymer blend includes a blend of polyvinyl alcohol polymers, the PVOH polymer blend may include a first PVOH polymer ("first PVOH polymer") which may include a modified PVOH copolymer containing a PVOH copolymer or one or more species of anionic monomer units (e.g., PVOH ter (or higher copolymer) polymer), and a second PVOH polymer ("second PVOH polymer") which may include a modified PVOH copolymer containing a PVOH copolymer or one or more species of anionic monomer units (e.g., PVOH ter (or higher copolymer) polymer). In some embodiments, the PVOH polymer blend may include only the first PVOH polymer and the second PVOH polymer (e.g., a binary blend of the two polymers). Alternatively, or in addition, the PVOH polymer blend or the fibers or nonwoven webs made therefrom may be characterized by not containing, or substantially not containing, other polymers (e.g., other polymers in general, in particular other PVOH-based polymers, or both). As used herein, “substantially uncontaining” means that the first and second PVOH polymers constitute at least 95 wt.%, at least 97 wt.%, or at least 99 wt.% of the total amount of water-soluble polymers in the water-soluble fiber or film. In other embodiments, the fiber may contain one or more additional water-soluble polymers. For example, the PVOH polymer blend may contain a third PVOH polymer, a fourth PVOH polymer, a fifth PVOH polymer, etc. (e.g., one or more additional PVOH copolymers or modified PVOH copolymers, with or without anionic monomer units). For example, the fiber may contain at least a third (or fourth, fifth, etc.) water-soluble polymer other than PVOH polymers (e.g., other than PVOH homopolymers or PVOH copolymers, with or without anionic monomer units).

[0070] The degree of hydrolysis (DH) of the PVOH copolymer contained in the fibers of this disclosure, prior to chemical modification with a modifying agent, can range from about 75% to about 99.9% (for example, in the case of cold water-soluble compositions, about 79% to about 99.9%, about 79% to about 92%, about 80% to about 90%, about 88% to about 92%, about 86.5% to about 89%, or about 88%, 90%, or 92%; about 90% to about 99%, about 92% to about 99%, about 95% to about 99%, about 98% to about 99%, about 98% to about 99.9%, about 96%, about 98%, about 99%, or over 99%). As the degree of hydrolysis decreases, the fibers made from the polymer will have reduced mechanical strength but will dissolve more quickly at temperatures below about 20°C. As the degree of hydrolysis increases, fibers or films made from the polymer tend to become more mechanically stronger and less thermoformable. The degree of hydrolysis of PVOH can be chosen such that the water solubility of the polymer is temperature-dependent, and therefore the solubility of fibers made from the polymer is also affected. In one option, the fibers are cold-water soluble. For a copolymer of vinyl acetate and vinyl alcohol that does not contain any other monomers (e.g., copolymers that do not copolymerize with anionic monomers), cold-water soluble fibers that are soluble in water at temperatures below 10°C can contain PVOH with a degree of hydrolysis in the range of about 75% to about 90%, or about 80% to about 90%, or about 85% to about 90%. In another option, the fibers are hot-water soluble. For a copolymer of vinyl acetate and vinyl alcohol that does not contain any other monomers (e.g., copolymers that do not copolymerize with anionic monomers), hot-water soluble fibers that are soluble in water at temperatures of at least about 60°C can contain PVOH with a degree of hydrolysis of at least about 98%. Copolymers of vinyl acetate and vinyl alcohol may be called PVOH copolymers, but those containing an anionic monomer moiety may be called modified PVOH copolymers or anionic modified PVOH copolymers. Both PVOH copolymers and modified PVOH copolymers can be polymers in fibers before chemical modification with a modifying agent.

[0071] The degree of hydrolysis of polymer blends is also arithmetic weighted, mean degree of hydrolysis.

number

number

number

[0072] The viscosity (μ) of PVOH polymers is determined by measuring a freshly prepared solution using a Brookfield LV viscometer equipped with a UL adapter, as described in the British standard EN ISO 15023-2:2006 Annex E Brookfield test method. The international standard describes the viscosity of a 4% polyvinyl alcohol aqueous solution at 20°C. All viscosities specified herein (in centipoise (cP)) should be understood to refer to the viscosity of a 4% polyvinyl alcohol aqueous solution at 20°C, unless otherwise specified. Similarly, where a polymer is described as having (or not having) a particular viscosity, unless otherwise specified, the particular viscosity is the average viscosity of the polymer, which is intended to essentially have the corresponding molecular weight distribution, i.e., the weighted natural log-mean viscosity as described below. The viscosity of a PVOH polymer is determined by the weight-average molecular weight of the PVOH polymer.

number

number

[0073] In embodiments, the PVOH polymer may have a viscosity of about 1.0 to about 50.0 cP, about 1.0 to about 40.0 cP, or about 1.0 to about 30.0 cP, for example, about 4 cP, 8 cP, 15 cP, 18 cP, 23 cP, or 26 cP. In embodiments, the PVOH homopolymer and / or copolymer may have a viscosity of about 1.0 to about 40.0 cP, or about 5 cP to about 23 cP, for example, about 1 cP, 1.5 cP, 2 cP, 2.5 cP, 3 cP, 3.5 cP, 4 cP, 4.5 cP, 5 cP, 5.5 cP, 6 cP, 6.5 cP, 7 cP, 7.5 cP, 8 cP, 8.5 cP, 9 cP, It may have a viscosity of 9.5 cP, 10 cP, 11 cP, 12 cP, 13 cP, 14 cP, 15 cP, 17.5 cP, 18 cP, 19 cP, 20 cP, 21 cP, 22 cP, 23 cP, 24 cP, 25 cP, 26 cP, 27 cP, 28 cP, 29 cP, 30 cP, 31 cP, 32 cP, 33 cP, 34 cP, 35 cP, or 40 cP. In the embodiment, the PVOH homopolymer and / or copolymer may have a viscosity of about 21 cP to 26 cP. In the embodiment, the PVOH homopolymer and / or copolymer may have a viscosity of about 5 cP to 14 cP. In the embodiment, the PVOH homopolymer and / or copolymer may have a viscosity of about 5 cP to about 23 cP.

[0074] For reference, in the polymer blend, the first PVOH polymer is shown to have a first 4% solution viscosity (μ1) at 20°C, and the second PVOH polymer is shown to have a second 4% solution viscosity (μ2) at 20°C. In various embodiments, the first viscosity μ1 may range from about 4 cP to about 70 cP (e.g., at least about 4, 8, 10, 12 or 16 cP and / or up to about 12, 16, 20, 24, 28, 30, 32, 35, 37, 40, 45, 48, 50, 56, 60 or 70 cP, e.g., about 4 cP to about 70 cP, about 4 cP to about 60 cP, about 4 cP to about 46 cP, about 4 cP to about 24 cP, about 10 cP to about 16 cP, or about 10 cP to about 20 cP, or about 20 cP to about 30 cP). Alternatively, or in addition, the second viscosity μ2 may range from about 4 cP to about 70 cP (e.g., at least about 4, 8, 10, 12 or 16 cP and / or up to about 12, 16, 20, 24, 28, 30, 32, 35, 37, 40, 45, 48, 50, 56, 60 or 70 cP, e.g., about 12 cP to about 30 cP, about 10 cP to about 16 cP, or about 10 cP to about 20 cP, or about 20 cP to about 30 cP). If the PVOH polymer blend contains three or more PVOH polymers selected from PVOH polymers and PVOH copolymers, the aforementioned viscosity values ​​may apply individually to each PVOH polymer or PVOH copolymer. Therefore, the weight-average molecular weight of the water-soluble polymer containing the first PVOH copolymer and the second PVOH copolymer may be in the range of, for example, about 30,000 to about 175,000, or about 30,000 to about 100,000, or about 55,000 to about 80,000. When referring to the average viscosity of the PVOH polymer blend, the weighted natural log-mean viscosity is used.

number

number

number

[0075] In embodiments in which the water-soluble fiber comprises a blend of polyvinyl alcohol homopolymers and polyvinyl alcohol copolymers, the relative amounts of homopolymers and copolymers are not particularly limited. The polyvinyl alcohol homopolymer may constitute about 15 wt.% to about 70 wt.% of the total weight of the water-soluble polymer blend, for example, at least about 15 wt.%, at least about 20 wt.%, at least about 25 wt.%, at least about 30 wt.%, at least about 40 wt.%, at least about 50 wt.%, or at least about 60 wt.%, and up to about 70 wt.%, up to about 60 wt.%, up to about 50 wt.%, up to about 40 wt.%, or up to about 30 wt.%, based on the total weight of the water-soluble polymer blend, and may be a single homopolymer or a blend of one or more homopolymers (e.g., having differences in viscosity and / or degree of hydrolysis). The remainder of the water-soluble polymer blend may be water-soluble polyvinyl alcohol copolymers. Without intending to be bound by theory, it is assumed that as the amount of homopolymer decreases to less than about 15 wt.%, the ability of the polyvinyl alcohol homopolymer and copolymer blend to form fibers decreases. Water-soluble polyvinyl alcohol copolymers can constitute about 30 wt.% to about 85 wt.% of the total weight of the water-soluble polymer blend, for example, based on the total weight of the water-soluble polymer blend, at least about 30 wt.%, at least about 40 wt.%, at least about 50 wt.%, at least about 60 wt.%, at least about 70 wt.%, at least about 75 wt.%, or at least about 80 wt.%, and up to about 85 wt.%, up to about 80 wt.%, up to about 70 wt.%, up to about 60 wt.%, up to about 50 wt.%, or up to about 40 wt.%, and may be a single copolymer or a blend of one or more copolymers. The blend may consist of polyvinyl alcohol homopolymers and polyvinyl alcohol copolymers. The blend may consist of polyvinyl alcohol homopolymers and multiple polyvinyl alcohol copolymers. The blend may consist of more than one polyvinyl alcohol homopolymer and more than one polyvinyl alcohol copolymer.

[0076] In the embodiments, the fibers include polyvinyl acetate, polyvinyl alcohol homopolymer, polyvinyl alcohol copolymer, modified polyvinyl alcohol copolymer, or a combination thereof. In the embodiments, the fibers include polyvinyl alcohol homopolymer, polyvinyl alcohol copolymer, modified polyvinyl alcohol copolymer, or a combination thereof. In the embodiments, the fibers include polyvinyl alcohol homopolymer. In the embodiments, the fibers include polyvinyl alcohol copolymer. In the embodiments, the fibers include polyvinyl alcohol copolymer containing anionic monomer units (partially). In the embodiments, the fibers include anionic monomer units, and the anionic monomer units include carboxylate, sulfonate, or a combination thereof. In the embodiments, the polyvinyl alcohol polymer is water-soluble before the fibers are mixed with the modifier. In the embodiments, the polyvinyl alcohol polymer has a degree of modification ranging from about 0 mol% to about 10 mol% before the addition of the modifier. In the embodiment, the polymer in the fiber before modification with the modifying agent has a degree of hydrolysis of more than about 79% and less than about 99.99% (e.g., about 79% to about 96% or about 88% to about 99.99%) before the fiber is mixed with the hydrolyzing agent solution.

[0077] The fibers of this disclosure may include water-soluble polymers other than PVOH, PVOH copolymers, and modified PVOH copolymers, but not limited to those comprising polyacrylates, water-soluble acrylate copolymers, polyvinylpyrrolidone, polyethyleneimine, and pullulan; water-soluble natural polymers, but not limited to those comprising guar gum, acacia gum, xanthan gum, carrageenan, and water-soluble starch; water-soluble polymer derivatives, but not limited to those comprising modified starch, ethoxylated starch, and hydroxypropylated starch; copolymers of the foregoing; and any combination of any additional polymers or copolymers described herein. Other water-soluble polymers may include polyalkylene oxides, polyacrylamides, polyacrylic acids and their salts, water-soluble cellulose, cellulose ethers, cellulose esters, celluloseamides, polyvinyl acetate, polycarboxylic acids and their salts, polyamino acids, polyamides, gelatin, methylcellulose, carboxymethylcellulose and its salts, dextrin, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, maltodextrin, polymethacrylates; and any combination of the foregoing. Such water-soluble polymers, whether PVOH or otherwise, are commercially available from various suppliers.

[0078] In embodiments, the fibers include a polyvinyl alcohol polymer and an additional polymer comprising polyvinyl alcohol, polyvinyl acetate, polyacrylate, water-soluble acrylate copolymer, polyvinylpyrrolidone, polyethyleneimine, pullulan, guar gum, acacia gum, xanthan gum, carrageenan, starch, modified starch, polyalkylene oxide, polyacrylamide, polyacrylic acid, cellulose, cellulose ether, cellulose ester, celluloseamide, polycarboxylic acid, polyamino acid, polyamide, gelatin, dextrin, copolymers of the aforementioned, and any combination of the aforementioned additional polymers or copolymers.

[0079] The fiber may further comprise a water-insoluble fiber-forming material. Suitable water-insoluble fiber-forming materials include, but are not limited to, cotton, polyester, copolyester, polyethylene (e.g., high-density polyethylene and low-density polyethylene), polypropylene, wood pulp, fluff pulp, Manila hemp, viscose, insoluble cellulose, insoluble starch, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, white pine, silk, tendon, cut gut, hair, sea silk, mohair, angora, cashmere, collagen, actin, nylon, dacron, rayon, bamboo fiber, modal, diacetate fiber, triacetate fiber, polyester, copolyester, polylactide (PLA), polyethylene terephthalate (PET), polypropylene (PP), and combinations thereof. In embodiments, the water-insoluble fiber does not include cotton or rayon. In the embodiment, the water-insoluble fiber includes wool, diacetate, triacetate, nylon, PLA, PET, PP, or a combination thereof.

[0080] The fibers may further include non-fiber-forming materials, which are referred to herein as auxiliary or secondary components. The auxiliary agents may include, but are not limited to, activators and treatment agents such as activators, plasticizers, plasticizer compatibilizers, surfactants, lubricants, release agents, fillers, bulking agents, crosslinking agents, antiblocking agents, antioxidants, detackeners, defoamers, nanoparticles such as layered silicate nanoclay (e.g., sodium montmorillonite), bleaching agents (e.g., sodium metabisulfite, sodium bisulfite, or others), bittering agents (e.g., denatonium salts such as denatonium benzoate, denatonium sugars, and denatonium chloride; sucrose octaacetate; quinine; flavonoids such as quercetin and naringenin; and cassinoids such as casin and brucine), and pungent agents (e.g., capsaicin, piperine, allyl isocyanate, and resinferatoxin), as well as other functional ingredients, in amounts suitable for their intended purpose. As used herein, unless otherwise specified, “auxiliaries” include secondary additives, treatment agents, and activators. Specific such auxiliaries and treatment agents may be selected from those suitable for use in water-soluble fibers, water-insoluble fibers, nonwoven webs, or water-soluble films.

[0081] In embodiments, the fibers of this disclosure are free of additives. As used herein, unless otherwise specified, “free of additives” with respect to a fiber means that the fiber contains less than about 0.01 wt.%, less than about 0.005 wt.%, or less than about 0.001 wt.% of an additive, based on the total weight of the fiber.

[0082] Plasticizers are liquids, solids, or semi-solids added to materials (usually resins or elastomers) to make them softer, more flexible (by lowering the glass transition temperature of the polymer), and easier to process. Alternatively, polymers can be plasticized from within by chemically modifying the polymer or monomer. In addition, or instead, polymers can be plasticized from the outside by adding a suitable plasticizer. Water is recognized as a very efficient plasticizer for PVOH and other polymers, including but not limited to water-soluble polymers; however, its volatility limits its use because polymer films need to have at least some degree of resistance (robustness) to variations in ambient conditions, including low and high relative humidity.

[0083] Plasticizers may include, but are not limited to, glycerin, diglycerin, sorbitol, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol up to 400 MW, neopentyl glycol, trimethylolpropane, polyether polyol, sorbitol, 2-methyl-1,3-propanediol (MPDiol®), ethanolamine, and mixtures thereof. The total amount of non-aqueous plasticizer provided in the fiber may range from about 1 wt.% to about 45 wt.%, or about 5 wt.% to about 45 wt.%, or about 10 wt.% to about 40 wt.%, or about 20 wt.% to about 30 wt.%, or about 1 wt.% to about 4 wt.%, or about 1.5 wt.% to about 3.5 wt.%, or about 2.0 wt.% to about 3.0 wt.%, for example, about 1 wt.%, about 2.5 wt.%, about 5 wt.%, about 10 wt.%, about 15 wt.%, about 20 wt.%, about 25 wt.%, about 30 wt.%, about 35 wt.%, or about 40 wt.% based on the total fiber weight.

[0084] Surfactants for use in fibers are well known in the art. Surfactants for use in films are also well known in the art and can be suitably used in the fibers and / or nonwoven webs of this disclosure. If necessary, surfactants are included to assist in the dispersion of fibers during processing. Suitable surfactants for the fibers of this disclosure include, but are not limited to, dialkyl sulfosuccinates, lactylated fatty acid esters of glycerol and propylene glycol, lactic acid esters of fatty acids, sodium alkyl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, alkyl polyethylene glycol ethers, lecithin, acetylated fatty acid esters of glycerol and propylene glycol, sodium lauryl sulfate, acetylated fatty acid esters, myristyldimethylamine oxide, trimethyl tallowalkylammonium chloride, quaternary ammonium compounds, alkali metal salts of higher fatty acids containing about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylate sulfates, alkylbenzene sulfonates, monoethanolamine, lauryl alcohol ethoxylate, propylene glycol, diethylene glycol, salts thereof, and any combination of the foregoing.

[0085] Suitable surfactants may include nonionic, cationic, anionic, and zwitterionic classes. Suitable surfactants, but are not limited to, include propylene glycol, diethylene glycol, monoethanolamine, polyoxyethylene-modified polyoxypropylene glycol, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylene glycol and alkanolamide (nonionic), polyoxyethylene-modified amines, quaternary ammonium salts and quaternary polyoxyethylene-modified amines (cationic), alkali metal salts of higher fatty acids containing about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylate sulfates and alkylbenzene sulfonates (anionic), as well as amine oxides, N-alkyl betaines and sulfobetaines (zwitterionic). Other suitable surfactants include sodium dioctyl sulfosuccinate, lactyl fatty acid esters of glycerin and propylene glycol, lactic acid esters of fatty acids, sodium alkyl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acetylated fatty acid esters of glycerin and propylene glycol, and acetylated fatty acid esters, as well as combinations thereof. In various embodiments, the amount of surfactant in the fiber is in the range of about 0.01 wt.% to about 2.5 wt.%, about 0.1 wt.% to about 2.5 wt.%, about 1.0 wt.% to about 2.0 wt.%, about 0.01 wt% to 0.25 wt%, or about 0.10 wt% to 0.20 wt%.

[0086] In embodiments, the fibers and / or nonwoven webs of the present disclosure may contain activators. The activators may be added to the fibers themselves, or during the carding of the nonwoven web, and / or to the nonwoven web before binding. Activators added to the fibers during carding may be distributed throughout the nonwoven web. Activators added to the nonwoven web after carding but before binding can be selectively added to one or both surfaces of the nonwoven web. Furthermore, activators can be added to the surface of pouches or other articles prepared from the nonwoven web. In embodiments, the activators may be provided as part of a plurality of fibers, dispersed within the nonwoven web, provided on the surface of the nonwoven web, or a combination thereof.

[0087] The activator provides additional functionality to the nonwoven web when present in the fiber and / or nonwoven web in an amount ranging from at least about 1 wt%, or in the range of about 1 wt% to about 99 wt%. In embodiments, the activator may include, but is not limited to, one or more components including enzymes, oils, fragrances, colorants, odor absorbers, air fresheners, insecticides, fertilizers, activators, acid catalysts, metal catalysts, ion scavengers, detergents, disinfectants, surfactants, bleaches, bleaching agents, fabric softeners, or combinations thereof. In embodiments, the activator may include colorants, surfactants, or combinations thereof. The activator may take any desired form, including solids (e.g., powders, granules, crystals, flakes, or ribbons), liquids, mulls, pastes, gases, etc., and may be encapsulated as needed.

[0088] In certain embodiments, the activator may include an enzyme. Preferred enzymes include those classified into any one of the six conventional Enzyme Committee (EC) classifications: EC1 oxidoreductases (catalyzing oxidation / reduction reactions), EC2 transferases (transferring functional groups, e.g., methyl or phosphate groups), EC3 hydrolases (catalyzing hydrolysis of various bonds), EC4 lyases (cleaving various bonds by means other than hydrolysis and oxidation), EC5 isomerases (catalyzing intramolecular isomerization changes), and EC6 ligases (joining two molecules by covalent bonds). Examples of such enzymes include EC1 dehydrogenases and oxidases, EC2 transaminases and kinases, EC3 lipases, cellulases, amylases, mannases and peptidases (also known as proteases or protein-degrading enzymes), EC4 decarboxylases, EC5 isomerases and mutases, and EC6 synthetases and synthases. Suitable enzymes from each classification are described, for example, in U.S. Patent No. 9,394,092, the full disclosure of which is incorporated herein by reference.

[0089] Enzymes for use in laundry and dishwashing applications may contain one or more of the following oxido-reductase enzymes, including proteases, amylases, lipases, dehydrogenases, transaminases, kinases, cellulases, manases, peptidases, decarboxylases, isomerases, mutases, synthetases, synthases, and oxido-reductase enzymes that catalyze the formation of bleach.

[0090] Oils other than fragrances may contain fragrances and colorants.

[0091] In one embodiment, the activator includes a fragrance or a combination of fragrances. Preferred fragrances include, but are not limited to, spearmint oil, cinnamon oil, wintergreen oil (methyl salicylate), peppermint oil, and natural fruit fragrances including synthetic fragrances and citrus oils.

[0092] In some embodiments, the activator may be a colorant or a combination of colorants. Examples of suitable colorants include food colorants, caramel, paprika, cinnamon, and saffron. Other examples of suitable colorants can be found in U.S. Patent No. 5,002,789, which is incorporated herein by reference in its entirety.

[0093] Another class of embodiments includes one or more odor absorbers as activators. Suitable odor absorbers for use as activators according to this disclosure include, but are not limited to, zeolite and zinc complex salts of ricinoleic acid. Odor-absorbing activators may also include, but are not limited to, fixatives known in the art as nearly odor-neutral fragrances, including radicans, Styrax japonica extracts, and derivatives of abietic acid.

[0094] Embodiments of another class include one or more fragrances as activators. As used herein, the term fragrance means any applicable material that volatilizes sufficiently to produce a scent. Embodiments including a fragrance as an activator may include fragrances that are pleasant to humans, or conversely, fragrances that repel humans, animals, and / or insects. Preferred fragrances include, but are not limited to, fruit fragrances including lemon, apple, cherry, grape, pear, pineapple, orange, strawberry, and raspberry; musk; and floral fragrances including, but are not limited to, lavender-like, rose-like, iris-like, and carnation-like. Where necessary, fragrances are also non-scenting agents. Other fragrances include, but are not limited to, herbaceous fragrances including rosemary, thyme, and sage; and forest fragrances derived from pine, spruce, and other woody scents. Fragrances may also be derived from various oils, including essential oils, or from plant materials, including, but not limited to, peppermint and spearmint. Suitable aromatic oils can be found in U.S. Patent No. 6,458,754, which is incorporated herein by reference in its entirety.

[0095] The fragrance may include perfume. The perfume may include neat perfume, encapsulated perfume, or a mixture thereof. Preferably, the perfume includes neat perfume. A portion of the perfume may be encapsulated in a core-shell capsule. In another type of embodiment, the perfume is not encapsulated in a core-shell capsule.

[0096] As used herein, the term “perfume” encompasses perfume raw materials (PRMs) and perfume formulations. “Perfume raw material” as used herein means a compound having a molecular weight of at least about 100 g / mol and useful, either alone or in combination with other perfume raw materials, for imparting odor, fragrance, essence, or scent. As used herein, the terms “perfume component” and “perfume raw material” are interchangeable. “Formulation” as used herein means a mixture of two or more PRMs.

[0097] Applicable insect repellent fragrances comprise one or more of the dichlorvos, pyrethrin, allethrin, nared, and / or fenthion insecticides disclosed in U.S. Patent No. 4,664,064, which is incorporated herein by reference in whole. Preferred insect repellents are citronellal (3,7-dimethyl-6-octanal), N,N-diethyl-3-methylbenzamide (DEET), vanillin, and volatile oils extracted from turmeric (Curcuma longa), kaffir lime (Citrus hystrix), citronella (Cymbopogon winterianus), and Thai basil (Ocimum americanum). Furthermore, applicable insect repellents may be mixtures of insect repellents.

[0098] In one class of embodiments, the activator according to the present disclosure comprises one or more pesticides. Suitable pesticides may include, but are not limited to, insecticides, herbicides, acaricides, fungicides, and larval tracticides.

[0099] Another class of embodiments includes one or more fertilizers as activators. As used herein, the term fertilizer applies to any applicable material that releases one or more of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, copper, iron, manganese, molybdenum, or zinc. Preferred fertilizers include, but are not limited to, zeolites. For example, clinoptilolite is a zeolite that releases potassium and, if pre-filled with ammonium, may also release nitrogen.

[0100] One class of embodiments includes an acid catalyst as an activator. As used herein, the term acid catalyst means any species that acts as a proton source and thereby accelerates a chemical reaction. In one embodiment, the acid catalyst is a non-oxidizing organic acid. A preferred organic acid is p-toluenesulfonic acid. In some embodiments, the activator, which is the acid catalyst, accelerates reactions including acetalization, esterification, or transesterification, but is not limited to these. Further acid-catalyzed reactions are well known in the art.

[0101] In one embodiment, the activator includes a metal catalyst. These catalysts mediate reactions including, but are not limited to, oxidation or reduction, hydrogenation, carbonylation, CH bond activation, and bleaching. Suitable metals to be used as metal catalysts include, but are not limited to, VIIIA and IB transition metals, such as iron, cobalt, nickel, copper, platinum, rhodium, ruthenium, silver, osmium, gold, and iridium. The metal mediating the catalytic reaction may be in any suitable oxidation state.

[0102] In alternative embodiments, the activator may optionally be an ion scavenger. Suitable ion scavengers include, but are not limited to, zeolites. Optionally, zeolites may be added as a water softener to a water-soluble packet containing a sealed laundry detergent or dishwashing detergent.

[0103] Inorganic and organic bleaching agents are suitable cleaning agents for use herein. Inorganic bleaching agents include, but are not limited to, perboric acid, percarbonate, superphosphate, persulfate, and persilicate, which are hydroxide salts. Inorganic hydroxide salts are typically alkali metal salts. Alkali metal percarbonates, particularly sodium percarbonate, are suitable hydroxides for use herein. Organic bleaching agents may include diacyl and tetraacyl peroxides, and, in particular, but are not limited to, organic peroxy acids, which include diperoxide decanedioic acid, diperoxytetradecanedioic acid, and diperoxyhexadecanedioic acid. Dibenzoyl peroxide is a suitable organic peroxy acid according to this disclosure. Other organic bleaching agents include peroxy acids, specific examples of which are alkyl peroxy acids and allyl peroxy acids.

[0104] In one embodiment, the activator may include a bleaching sensitizer comprising an organic peracid precursor that enhances the bleaching action of the cleaning process at temperatures of 60°C and below. Suitable bleaching sensitizers for use herein include compounds that, under hyperhydrolysis conditions, yield aliphatic peroxycarboxylic acids having 1 to 10 carbon atoms, or 2 to 4 carbon atoms, and / or optionally substituted perbenzoic acids. Suitable substances have O-acyl and / or N-acyl groups of a specific number of carbon atoms, and / or optionally substituted benzoyl groups. Suitable substances include, but are not limited to, polyacylated alkylenediamines, particularly tetraacetylethylenediamine (TAED); acylated triazine derivatives, particularly 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT); acylated glycoluryls, particularly tetraacetylglycoluryl (TAGU); N-acylimides, particularly N-nonanoylsuccinimide (NOSI); acylated phenolsulfonates, particularly n-nonanoyl- or isononanoyloxybenzenesulfonates (n- or iso-NOBS); carboxylic acid anhydrides, particularly phthalic anhydrides; acylated polyhydric alcohols, particularly triacetin; ethylene glycol diacetate and 2,5-diacetoxy-2,5-dihydrofuran; and also triethylacetyl citrate (TEAC).

[0105] In embodiments comprising a fabric softener as an activator, various washable fabric softeners, in particular the fine smectite clay disclosed in U.S. Patent No. 4,062,647, which is entirely incorporated herein by reference, and other softening clays known in the art, can be used, as needed, to provide a fabric softener that is both clean and beneficial. The clay softeners can be used in combination with amines and cationic softeners, for example, as disclosed in U.S. Patents No. 4,375,416 and No. 4,291,071, which are entirely incorporated herein by reference.

[0106] In embodiments, the activator may include a bactericide. Suitable bactericides for use herein may include, but are not limited to, hydrogen peroxide, inorganic peroxides and their precursors, sodium metabisulfite, quaternary ammonium cation-based compounds, chlorine, activated carbon, and hypochlorites.

[0107] In embodiments, the activator may include surfactants. Suitable surfactants for use herein are, but are not limited to, propylene glycol, diethylene glycol, monoethanolamine, polyoxyethylene-modified polyoxypropylene glycol, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylene glycol and alkanolamides (nonionic), polyoxyethylene-modified amines, quaternary ammonium salts and quaternary polyoxyethylene-modified amines (cationic), alkali metal salts of higher fatty acids containing about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylates This may include polysorbates and alkylbenzene sulfonates (anionic), amine oxides, N-alkyl betaines and sulfobetaines (zwitterionic), sodium dioctyl sulfosuccinate, lactyl fatty acid esters of glycerin and propylene glycol, lactyl acid esters of fatty acids, sodium alkyl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acetylated fatty acid esters of glycerin and propylene glycol, and acetylated fatty acid esters, as well as combinations thereof.

[0108] The activator may be solid or liquid. A solid activator may have an average particle size of at least about 0.01 μm (e.g., Dv50), or a size in the range of, for example, about 0.01 μm to about 2 mm. A liquid activator may be applied directly to a nonwoven web, mixed with a carrier powder, or microencapsulated. In embodiments including a carrier powder, the average particle size of the carrier powder may be at least about 0.01 μm, or in the range of, for example, about 0.01 μm to about 2 mm.

[0109] In one embodiment, the activator is encapsulated to allow for controlled release of the activator. Suitable microcapsules may contain or be made from one or more of the following: melamine formaldehyde, polyurethane, urea formaldehyde, chitosan, polymethyl methacrylate, polystyrene, polysulfone, polytetrahydrofuran, gelatin, gum arabic, starch, polyvinylpyrrolidone, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, arabinogalactan, polyvinyl alcohol, polyacrylic acid, ethylcellulose, polyethylene, polymethacrylate, polyamide, poly(ethylene vinyl acetate), cellulose nitrate, silicone, poly(lactidoglycolide), paraffin, carnauba wax, whale wax, beeswax, stearic acid, stearyl alcohol, glyceryl stearate, shellac, cellulose phthalate acetate, zein, and combinations thereof. In one embodiment, the microcapsules are characterized by an average particle size of at least about 0.1 microns, or, for example, in the range of about 0.1 microns to about 200 microns (e.g., Dv50). In an alternative embodiment, the microcapsules may form aggregates of individual particles, for example, the individual particles having an average particle size of at least about 0.1 microns, or in the range of about 0.1 microns to about 200 microns.

[0110] The fibers to be processed can be formed by any process known in the art, such as wet cooling gel spinning, thermoplastic fiber spinning, meltblown, spunbond, electrospinning, spinning, continuous filament manufacturing methods, tow fiber manufacturing methods, and combinations thereof.

[0111] In embodiments, the fibers include fibers formed by wet-cooled gel spinning, melt-blown, spunbond, or a combination thereof. In embodiments, the fibers include fibers formed by wet-cooled gel spinning. In embodiments, the fibers include water-soluble fibers, and the nonwoven webs prepared therefrom are formed by a continuous melt-blown process. In embodiments, the fibers include water-soluble fibers, and the nonwoven webs prepared therefrom are formed by a continuous spunbond process. It is standard practice in the art to refer to the fibers and nonwoven webs by the process used to prepare them. Accordingly, any reference herein to, for example, “melt-blown fibers” or “carded nonwoven webs” should not be understood as a product-by-process limitation to a particular melt-blown or carding method, but rather as simply identifying a particular fiber or web. Accordingly, processing terms may be used to distinguish fibers and / or nonwovens without limiting the stated fibers and / or nonwovens to their preparation by any particular process.

[0112] The processed fibers can be formed as two-component fibers. As used herein, unless otherwise specified, “two-component fiber” means a fiber comprising two or more distinct regions of fiber-forming material, where the composition of the fiber-forming material differs by region, rather than a fiber comprising a blend of fiber-forming materials. Examples of two-component fibers, but not limited to these, include core-sheath two-component fibers, sea-island two-component fibers, and side-by-side two-component fibers. Core-sheath two-component fibers generally comprise a core having a first composition of fiber-forming material (e.g., a single fiber-forming material or a first blend of fiber-forming materials) and a sheath having a second composition of fiber-forming material (e.g., a single fiber-forming material different from the core material, or a second blend of fiber-forming materials different from the first blend of fiber-forming materials in the core). Sea-island two-component fibers generally comprise a first continuous “sea” region having a first composition of fiber-forming material, and inconspicuous “island” regions dispersed therein, having a second composition of fiber-forming material different from the first composition. A bicomponent fiber generally comprises a first region along the length of the fiber containing a first composition of the fiber-forming material, and at least a second region adjacent thereto along the length of the fiber containing a second composition of the fiber-forming material different from the first composition. Such bicomponent fibers are well known in the art.

[0113] The shape of the fiber is not particularly limited, but may have cross-sectional shapes including round, elliptical (also called ribbon), triangular (also called delta), trefoil, and / or other multi-lobed shapes (Figure 1). The shape of the fiber does not need to be perfectly geometric; for example, a fiber with a round cross-sectional shape does not need to have a perfect circle as its cross-sectional region, and a fiber with a triangular cross-sectional shape is generally understood to have rounded corners.

[0114] It is understood that the diameter of a fiber refers to the cross-sectional diameter of the fiber along its longest cross-sectional axis. When a fiber is described as having (or not having) a particular diameter, unless otherwise specified, the particular diameter is the average diameter of the particular fiber type being referenced; that is, multiple fibers prepared from polyvinyl alcohol fiber-forming material are intended to have an arithmetic mean fiber diameter across the multiple fibers. For shapes that are typically not considered to have a "diameter," such as triangular or multi-lobed shapes, the diameter refers to the diameter of the circle enclosing the fiber shape (Figure 1).

[0115] The fibers of this disclosure typically have diameters ranging from about 10 microns to 300 microns, for example, at least 10 microns, at least 15 microns, at least 20 microns, at least 25 microns, at least 50 microns, at least 100 microns or at least 125 microns and up to about 300 microns, up to about 275 microns, up to about 250 microns, up to about 225 microns, up to about 200 microns, up to about 100 microns, up to about 50 microns, up to about 45 microns, up to about 40 microns or up to about 35 microns, for example, in the range of about 10 microns to about 300 microns, about 50 microns to about 300 microns, about 100 microns to about 300 microns, about 10 microns to about 50 microns, about 10 microns to about 45 microns, or about 10 microns to about 40 microns. In embodiments, the fibers may have diameters greater than 100 microns to about 300 microns. In embodiments, the fibers comprise cellulose and have diameters in the range of about 10 to about 50 microns, about 10 to about 30 microns, about 10 to about 25 microns, about 10 to about 20 microns, or about 10 to about 15 microns. In embodiments, the fibers comprise a water-soluble fiber-forming material and have diameters in the range of about 50 to about 300 microns, about 100 to about 300 microns, about 150 to about 300 microns, or about 200 to about 300 microns. In embodiments, the diameters of the plurality of water-soluble fibers used to prepare the nonwoven web of the present disclosure are substantially uniform. As used herein, a fiber diameter is considered "substantially uniform" if the variation in diameter between fibers is less than 10%, for example, less than 8%, less than 5%, less than 2%, or less than 1%. Fibers having substantially uniform diameters can be prepared by wet cooling gel spinning or thermoplastic fiber spinning. Furthermore, when a blend of fiber types is used, the average diameter of the fiber blend can be determined using a weighted average of the individual fiber types.

[0116] The fibers of this disclosure may generally be of any length. In embodiments, the length of the fibers may be in the range of about 20 mm to about 100 mm, about 20 to about 90 mm, about 30 mm to about 80 mm, about 10 mm to about 60 mm, or about 30 mm to about 60 mm, for example, at least about 30 mm, at least about 35 mm, at least about 40 mm, at least about 45 mm or at least about 50 mm and up to about 100 mm, up to about 95 mm, up to about 90 mm, up to about 80 mm, up to about 70 mm or up to about 60 mm. In embodiments, the fiber length may be less than about 30 mm, or between about 0.25 mm and less than about 30 mm, for example, at least about 0.25 mm, at least about 0.5 mm, at least about 0.75 mm, at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 7.5 mm or at least about 10 mm and up to about 29 mm, up to about 28 mm, up to about 27 mm, up to about 26 mm, up to about 25 mm, up to about 20 mm or up to about 15 mm. The fibers can be prepared to any length by cutting and / or crimping the extruded polymer mixture. In embodiments, the fibers may be continuous filaments prepared by processes such as spunbond, meltblown, electrospinning and spinning, and the continuous filaments are prepared and supplied directly in web form. Furthermore, if a blend of fiber types is used, the average length of the fibers can be determined using a weighted average of the individual fiber types.

[0117] The fibers of this disclosure can generally have any length-to-diameter (L / D) ratio. In embodiments, the fiber length-to-diameter ratio may be greater than about 2, greater than about 3, greater than about 4, greater than about 6, greater than about 10, greater than about 50, greater than about 60, greater than about 100, greater than about 200, greater than about 300, greater than about 400, or greater than about 1000. Advantageously, the tactile feel of the nonwoven web can be controlled using the L / D ratio of the fibers in the nonwoven composition and the respective amounts of fibers having various L / D ratios. Generally, as the L / D of the fibers decreases, the stiffness and flex resistance increase and the feel becomes rougher. The fibers of this disclosure generally impart a rough feel to nonwoven webs containing them when the fibers have a low L / D ratio in the range of about 0.5 to about 15, or about 0.5 to about 25, or about 1 to about 5. Such low L / D fibers may be present in a nonwoven web in amounts ranging from approximately 0 to approximately 50% by weight, for example, from approximately 0.5 wt.% to approximately 25 wt.%, or from approximately 1 wt.% to approximately 15 wt.%, based on the total weight of fibers in the nonwoven web. If the amount of low L / D fibers in a nonwoven web is unknown, the amount can be estimated by visual inspection of a micrograph of the nonwoven web. As shown in Figure 4, a cluster of fibers with a visibly larger diameter and shorter cut rate relative to the total fiber population can be observed. Figure 4A is a micrograph of a nonwoven web with 0% low L / D fibers and a flexibility rank of 1, while Figure 4B is a micrograph of a nonwoven web with 25% low L / D fibers and a flexibility rank of 5.

[0118] The fibers of this disclosure may generally have any toughness. The toughness of a fiber correlates with the roughness of the fiber. Generally, as the toughness of a fiber decreases, the roughness of the fiber increases. The fibers of this disclosure have toughnesses of approximately 1 to approximately 100 cN / dtex, or approximately 1 to approximately 75 cN / dtex, or approximately 1 to approximately 50 cN / dtex, or approximately 1 to approximately 45 cN / dtex, or approximately 1 to approximately 40 cN / dtex, or approximately 1 to approximately 35 cN / dtex, or approximately 1 to approximately 30 cN / dtex, or approximately 1 to approximately 25 cN / dtex, or approximately 1 to approximately 20 cN / dtex, or approximately 1 to approximately 15 cN / dtex, or approximately 1 to approximately 10 cN / dtex, or approximately 1 to approximately 5 cN / dtex, or approximately 3 to approximately 8 cN / dtex, or approximately 4 to approximately 8 cN / The toughness may be in the range of dtex, or approximately 6 to approximately 8 cN / dtex, or approximately 4 to approximately 7 cN / dtex, or approximately 10 to approximately 20, or approximately 10 to approximately 18, or approximately 10 to approximately 16, or approximately 1 cN / dtex, approximately 2 cN / dtex, approximately 3 cN / dtex, approximately 4 cN / dtex, approximately 5 cN / dtex, approximately 6 cN / dtex, approximately 7 cN / dtex, approximately 8 cN / dtex, approximately 9 cN / dtex, approximately 10 cN / dtex, approximately 11 cN / dtex, approximately 12 cN / dtex, approximately 13 cN / dtex, approximately 14 cN / dtex, or approximately 15 cN / dtex. In the embodiment, the fiber may have a toughness of approximately 3 cN / dtex to approximately 10 cN / dtex. In the embodiment, the fiber may have a toughness of approximately 7 cN / dtex to approximately 10 cN / dtex. In one embodiment, the fiber may have a toughness of approximately 4 cN / dtex to approximately 8 cN / dtex. In another embodiment, the fiber may have a toughness of approximately 6 cN / dtex to approximately 8 cN / dtex.

[0119] The fibers of this disclosure may generally have any fineness. Fiber fineness correlates with the amount of fiber present in a cross-section of a yarn of a given thickness. Fiber fineness is the ratio of fiber mass to length. The principal physical unit of fiber fineness is 1 tex, which is equal to 1,000 m of fiber in weight of 1 g. Typically, the unit d tex is used, representing 1 g / 10,000 m of fiber. Fiber fineness can be selected to result in a nonwoven web having a suitable hardness / feel, torsional stiffness, light reflection and interaction, absorption of dyes and / or other activators / additives, ease of fiber spinning in the manufacturing process, and uniformity of the finished article. Generally, as the fiber fineness increases, the nonwoven fabric obtained therefrom exhibits higher uniformity, improved tensile strength, extensibility, and gloss. Furthermore, without intending to be bound by theory, it is assumed that the finer the fiber, the slower the dissolution time compared to larger fibers based on density. Furthermore, without intending to be bound by theory, when fiber blends are used, the average fineness of the fibers can be determined using a weighted average of the individual fiber components. Fibers can be characterized as very fine (dtex ≤ 1.22), fine (1.22 ≤ dtex ≤ 1.54), medium (1.54 ≤ dtex ≤ 1.93), slightly coarse (1.93 ≤ dtex ≤ 2.32), and coarse (dtex ≥ 2.32). Nonwoven webs of the present disclosure may contain fibers of very fine, fine, medium, slightly coarse, or a combination thereof. In embodiments, the fibers have finenesses in the range of about 1 dtex to about 10 dtex, about 1 dtex to about 7 dtex, about 1 dtex to about 5 dtex, about 1 dtex to about 3 dtex, or about 1.7 dtex to about 2.2 dtex. In embodiments, the fibers have a fineness of about 1.7 dtex. In this embodiment, the fibers have a fineness of approximately 2.2 dtex.

[0120] Wet cooling gel spinning

[0121] In the embodiments, the fibers of the present disclosure are formed according to a wet cooling gel spinning method, and the wet cooling gel spinning method is (a) A step of dissolving a fiber-forming material (polymer) in a solution to form a polymer mixture, wherein the polymer mixture optionally contains an auxiliary agent; (b) The step of extruding the polymer mixture through a spinal nozzle into a solidification bath to form an extruded polymer mixture; (c) The step of passing the extruded polymer mixture through a solvent exchange bath; (d) If necessary, wet-stretch the extruded polymer mixture; and (e) A step of finishing the extruded polymer mixture to provide fibers. Includes.

[0122] The solvent in which the fiber-forming polymer is dissolved can preferably be any solvent in which the polymer is soluble. In embodiments, the solvent in which the polymer is dissolved includes a polar aproton solvent. In embodiments, the solvent in which the polymer is dissolved includes dimethyl sulfoxide (DMSO).

[0123] Generally, a solidification bath contains a cooling solvent for gelling the extruded polymer mixture. The solidification bath can generally be at any temperature that promotes the solidification of the extruded polymer mixture. The solidification bath may contain a mixture of a solvent in which the polymer is soluble and a solvent in which the polymer is insoluble. The solvent in which the polymer is insoluble is generally the primary solvent, and the solvent in which the polymer is insoluble constitutes more than 50% of the mixture.

[0124] After passing through the solidification bath, the extruded polymer mixture gel may be passed through one or more solvent exchange baths. The solvent exchange baths are provided to exchange the polymer-soluble solvent for a polymer-insoluble solvent, further solidifying the extruded polymer mixture and replacing the polymer-soluble solvent with a solvent that evaporates more readily, thereby reducing the drying time. The solvent exchange baths may include a series of solvent exchange baths having a gradient between polymer-soluble and polymer-insoluble solvents, a series of solvent exchange baths having only polymer-insoluble solvents, or a single solvent exchange bath having only polymer-insoluble solvents.

[0125] The finished fibers are sometimes called staple fibers, short-cut fibers, or pulp. In embodiments, the finishing process includes drying the extruded polymer mixture. In embodiments, the finishing process includes cutting or crimping the extruded polymer mixture to form individual fibers. Wet stretching of the extruded polymer mixture results in a substantially uniform diameter of the extruded polymer mixture, and therefore of the fibers cut from it. Stretching is distinct from extrusion, as is well known in the art. In particular, extrusion is the process of producing fibers by forcing a resin mixture through a spinneret head, while stretching is the process of mechanically pulling the fibers in a machining direction to improve polymer chain orientation and crystallinity so as to increase fiber strength and toughness.

[0126] In embodiments in which the fibers are prepared by a wet cooling gel spinning method, the fiber-forming polymer may generally be any fiber-forming polymer or a blend thereof, for example, two or more different polymers, as generally described herein. In improvements to the above embodiments, the polymer(s) may be, for example, 10 to 10,000,000, for example, at least 10, at least 20, at least 50, at least 100, at least 200, at least 300, at least 400, at least 500, at least 750 or at least 1000 and up to 10,000,000, up to 5,000,000, up to 2,500,000, up to 1,000,000, up to 900,000, up to 750,000, up to 500,000, up to 250,000, up to 100,000, up to 90,000, up to 75, The DP may have any DP in the range of 000, up to 50,000, up to 25,000, up to 12,000, up to 10,000, up to 5,000, or up to 2,500, for example, 1000 to about 50,000, 1000 to about 25,000, 1000 to about 12,000, 1000 to about 5,000, 1000 to about 2,500, about 50 to about 12,000, about 50 to about 10,000, about 50 to about 5,000, about 50 to about 2,500, about 50 to about 1000, about 50 to about 900, about 100 to about 800, about 150 to about 700, about 200 to about 600, or about 250 to about 500. In embodiments, DP is at least 1,000. In one embodiment, the fiber-forming polymer comprises polyvinyl alcohol having a DP in the range of 1,000 to about 50,000, 1,000 to about 25,000, 1,000 to about 12,000, 1,000 to about 5,000, 1,000 to about 2,500, about 50 to about 12,000, about 50 to about 10,000, about 50 to about 5,000, about 50 to about 2,500, about 50 to about 1,000, about 50 to about 900, about 100 to about 800, about 150 to about 700, about 200 to about 600, or about 250 to about 500. In embodiments, the fiber-forming polymer comprises polyvinyl alcohol having a DP in the range of 1,000 to about 50,000, 1,000 to about 25,000, 1,000 to about 12,000, 1,000 to about 5,000, or 1,000 to about 2,500.

[0127] The wet-cooled gel spinning method offers one or more advantages, such as providing fibers containing blends of water-soluble polymers, providing control over fiber diameter, providing relatively large diameter fibers, providing control over fiber length, providing control over fiber toughness, providing high-toughness fibers, providing fibers from polymers with high degrees of polymerization, and / or providing fibers that can be used to provide self-supporting nonwoven webs. Continuous processes such as spunbond, meltblown, electrospinning, and spinning generally do not allow for blending water-soluble polymers (e.g., due to the difficulty of matching the melt indices of various polymers), forming large diameter fibers (e.g., over 50 microns), controlling fiber length, providing high-toughness fibers, or using polymers with high degrees of polymerization. Furthermore, the wet-cooled gel spinning method is advantageous because it is not limited to melt-processable polymers and therefore allows for obtaining fibers made from fiber-forming materials having very high molecular weight, high melting point, low melt flow index, or a combination thereof, providing fibers with stronger physical properties and different chemical functionalities compared to fibers prepared by hot extrusion.

[0128] Methods for preparing stapled and continuous fibers are well known in the art. When stapled or continuous fibers are carded, nonwoven webs are bonded. Methods for bonding stapled fibers are well known in the art and may include air bonding (heat), calendering (heat and pressure), and chemical bonding. Nonwoven webs of the present disclosure may be bonded thermally or chemically. Nonwoven webs can generally be porous with varying pore sizes, morphology, and web heterogeneity. The physical properties of the fibers and the type of bonding may affect the porosity of the resulting nonwoven web. Calendering is achieved by applying heat and pressure and typically maintains the pore size, shape, and arrangement produced by the carding method. The conditions for calendering can be easily determined by those skilled in the art. Generally, if the heat and / or pressure applied is too low, the fibers will not bond sufficiently to form a self-supporting web, and if the heat and / or pressure is too high, the fibers will begin to fuse together. Fiber chemistry determines the upper and lower limits of heat and / or pressure for calendering. Without intending to be bound by theory, it is assumed that polyvinyl alcohol-based fibers decompose at temperatures above 235°C. Methods for embossing fibers for calendering are known. Embossing can be one-sided or two-sided. Typically, embossing of water-soluble fibers involves one-sided embossing using a single embossing roll consisting of a regular circular array and a steel roll having a flat surface. As embossing increases (e.g., surface features are imparted to the web), the surface area of ​​the web increases. Without intending to be bound by theory, it is expected that as the surface area of ​​the web increases, the solubility of the web will increase. Thus, the solubility properties of a nonwoven web can be advantageously tuned by altering the surface area through embossing.

[0129] In contrast to calendering, chemical bonding typically involves coating carding fibers under pressure using a binder solution of waste polymers left over from fiber preparation, resulting in smaller, less regular pores compared to those in the carding. Generally, the solvent can be any solvent that solubilizes the binder. Typically, the solvent in the chemical bonding solution is water. While not strictly theoretical, it is believed that a non-porous, water-dispersible nonwoven web can be formed if the polymer solution used for chemical bonding is sufficiently concentrated and / or under sufficient pressure. The solvent used for chemical bonding induces partial solubilization of the fibers present in the web, welding and bonding the fibers together. The polyvinyl alcohol binder provided in the solution assists the welding process, resulting in a more mechanically robust web. The temperature of the polymer solution is not particularly limited and can be provided at room temperature (approximately 23°C).

[0130] In some embodiments, a second layer of fibers can be used to bond the nonwoven web. Without intending to be bound by theory, it is conceivable that fibers prepared by the meltblown method, such as water-soluble fibers, can be used to bond nonwoven webs using an in-line process. In particular, the nonwoven web can pass through a meltblown station, and as a result, the meltblown fibers can be deposited after melt extrusion and bond to each other as the meltblown fibers cool and solidify, thus bonding them to the deposited nonwoven web. The meltblown fibers can be of micro to nanoscale in length, and the meltblown fibers can be supplied onto the nonwoven web such that they constitute about 15% by weight, about 12% by weight, about 10% by weight, about 8% by weight, about 6% by weight, or about 5% by weight of the final nonwoven web, based on the total weight of the fibers in the final nonwoven web. Without intending to be bound by theory, it is believed that the inclusion of approximately 5% to 15% meltblown fibers can increase the mechanical integrity of the nonwoven web without substantially altering its solubility properties. Generally, when preparing meltblown fibers using polyvinyl alcohol fiber-forming materials, the polyvinyl alcohol polymer is either a homopolymer or copolymer, as the meltblown method requires a polymer with low viscosity and a high melt flow index.

[0131] Pore ​​sizes, while not limited to these, can be determined using high-magnification regular surface analysis techniques, including Brunauer-Emmett-Taylor theory (BET), small-angle X-ray scattering (SAXS), and molecular adsorption.

[0132] Generally, the fibers of this disclosure can be formed by any fiber processing known in the art, and then treated with a chemical modification after processing, the chemical modification not involving the hydrolysis of polymers.

[0133] This disclosure provides a method for processing fibers containing polymers such as polymers containing at least one vinyl acetate moiety and vinyl alcohol moiety as described herein, for example, at least one vinyl acetate moiety only, at least one vinyl alcohol moiety only, or both vinyl acetate moiety and vinyl alcohol moiety. In embodiments, the method includes contacting the surface of a fiber containing a polymer containing at least one vinyl acetate moiety or vinyl alcohol moiety as described herein with a modifying agent to chemically modify at least a portion of the polymer with the modifying agent in a region of the fiber including at least the surface of the fiber, thereby forming a modified fiber. In embodiments, the method includes mixing a fiber containing a polymer containing at least one vinyl acetate moiety or vinyl alcohol moiety as described herein, a modifying agent, and optionally a solvent for the modifying agent to chemically modify at least a portion of the polymer with the modifying agent and form a modified fiber. In embodiments, the fiber is insoluble in the solvent for the modifying agent. The degree of modification after contact between the fiber surface and the modifier, or after mixing the modifier and the solvent for the modifier, can be determined by any suitable method known to those skilled in the art, such as attenuated total internal reflection (ATR), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), solubility testing (e.g., the dissolution and disintegration test methods of the examples disclosed herein), titration (e.g., the titration method of the examples disclosed herein), or similar methods or a combination thereof. Titration determines the average degree of hydrolysis or chemical modification for the fiber. For fibers characterized by a constant degree of hydrolysis or modification across the cross-section of the fiber, the constant degree of hydrolysis or modification is the average degree of hydrolysis for the fiber. For fibers characterized by a core-sheath or core-shell type distribution or gradient distribution of the degree of hydrolysis or modification across the cross-section of the fiber, the titration test provides the average degree of hydrolysis or modification across all cross-sections of the fiber.As used herein, unless otherwise specified, if any portion of a fiber (e.g., outer surface or portion, shell surface or portion, and / or inner portion) has an increased degree of modification after mixing compared to the degree of hydrolysis of the starting fiber, then at least a portion of the fiber has a decreased degree of hydrolysis. It will be understood that a decrease in the degree of hydrolysis of any portion of the fiber will result in a decrease in the average degree of hydrolysis of the fiber as determined by titration. Therefore, if the average degree of hydrolysis of the fiber as determined by titration is lower after mixing the fiber with the modifier compared to the average degree of hydrolysis of the fiber before mixing, it will be understood that the degree of hydrolysis of at least a portion of the polyvinyl alcohol polymer in the fiber has decreased.

[0134] As used herein, unless otherwise specified, at least a portion of a fiber has an increased degree of modification if any portion of the fiber (e.g., outer surface or portion, sheath (shell) surface or portion, and / or inner portion) has a decreased degree of hydrolysis after contact with or mixing with respect to the degree of modification of the starting fiber.

[0135] In general, contact or mixing may involve immersing the fibers in a mixture of a modifier and a solvent for the modifier. In embodiments, contact or mixing may involve immersing the fibers in a two-phase solvent system containing a solvent for the modifier and the modifier. In embodiments, the two-phase solvent system may include water and an organic solvent. In embodiments, mixing may involve stirring a mixture of the fibers, the modifier, and the solvent for the modifier. In embodiments, contact may involve applying an energy source to the fibers, such as corona treatment, electron beam radiation, or UV radiation.

[0136] In embodiments, the method comprises mixing a modifier and fibers under conditions sufficient to provide a controlled amount of chemical modification (degree of modification) to the polymer and / or a controlled increase in chemical modification (degree of modification) to the polymer. In embodiments, the method further comprises mixing a solvent for the modifier with the modifier and fibers. In embodiments, the method comprises mixing a modifier, fibers, and a solvent for the modifier under conditions sufficient to provide a controlled amount of chemical modification (degree of modification) to the polymer and / or a controlled increase in chemical modification (degree of modification) to the polymer. In embodiments, the method further comprises mixing a solvent for the modifier with the modifier and fibers. Generally, the amount of chemical modification of the treated fibers and / or the increase in chemical modification of the treated fibers can be designed and controlled by changing the reaction conditions. Reaction conditions that can be modified to provide a controlled amount of chemical modification and / or an increase in chemical modification include the selection of the modifier, the selection of the solvent for the modifier, the selection of the concentration of the modifier in the solvent, the reaction (mixing or contact) time, the reaction (mixing or contact) temperature, and the inclusion of an activator as needed.

[0137] Generally, as the reaction time increases, the chemical modification increases. Therefore, the reaction time can be selected to provide a desired increase in the chemical modification of the polymer constituting the fiber, such as polyvinyl alcohol, a copolymer of vinyl acetate and vinyl alcohol, or an anionic modified vinyl alcohol copolymer. The reaction time can range up to about 48 hours, for example, from about 1 minute to about 36 hours, from about 2 minutes to about 24 hours, from about 2 minutes to about 12 hours, from about 2 minutes to about 6 hours, from about 2 minutes to about 4 hours, from about 2 minutes to about 2 hours, from about 2 minutes to about 1 hour, from about 5 minutes to about 1 hour, from about 5 minutes to about 2 hours, from about 5 minutes to about 5 hours, from about 5 minutes to about 10 hours, from about 5 minutes to about 12 hours, from about 5 minutes to about 24 hours, from about 10 minutes to about 24 hours, and from about 15 minutes to about 24 hours. The mixing time can be approximately 30 minutes to 24 hours, approximately 1 hour to 24 hours, approximately 2 hours to 24 hours, approximately 3 hours to 24 hours, approximately 4 hours to 24 hours, approximately 5 hours to 24 hours, approximately 6 hours to 24 hours, approximately 8 hours to 24 hours, approximately 10 hours to 24 hours, approximately 12 hours to 24 hours, approximately 12 hours to 18 hours, approximately 14 hours to 20 hours, or approximately 16 hours to 24 hours. In one embodiment, the mixing time can be approximately 1 minute to 48 hours. In another embodiment, the mixing time can be approximately 1 hour to 36 hours. In yet another embodiment, the mixing time can be approximately 2 hours to 8 hours.

[0138] Generally, as the reaction temperature increases, the rate of chemical modification increases. Therefore, the reaction temperature can be selected in combination with the reaction time to provide a desired increase in the amount of chemical modification of the polymer constituting the fiber, such as polyvinyl alcohol, a copolymer of vinyl acetate and vinyl alcohol, or an anionic modified vinyl alcohol copolymer. The reaction temperature is not particularly limited, as long as the fiber is not dissolved or decomposed and the solvent, if present, remains liquid under heating conditions. Typical reaction temperatures include approximately 10°C to 200°C, approximately 10°C to 190°C, approximately 10°C to 180°C, approximately 10°C to 170°C, approximately 10°C to 160°C, approximately 10°C to 150°C, approximately 10°C to 140°C, approximately 10°C to 130°C, approximately 10°C to 120°C, approximately 10°C to 110°C, approximately 10°C to 100°C, approximately 10°C to 90°C, approximately 10°C to 80°C, and approximately 10°C. The reaction temperature can be from approximately 70°C, approximately 10°C to approximately 60°C, approximately 10°C to approximately 50°C, approximately 10°C to approximately 40°C, approximately 10°C to approximately 30°C, approximately 20°C to approximately 100°C, approximately 20°C to approximately 90°C, approximately 20°C to approximately 80°C, approximately 30°C to approximately 100°C, approximately 30°C to approximately 90°C, approximately 30°C to approximately 80°C, approximately 40°C to approximately 80°C, approximately 50°C to approximately 80°C, or approximately 60°C to approximately 80°C. While not strictly theoretical, it is thought that at higher temperatures, as the polarity of the solvent increases, the fibers begin to expand, gel, and / or dissolve. Therefore, the reaction temperature can be selected in combination with the solvent so that the fibers remain insoluble and do not decompose. In embodiments, the method further includes the step of heating the fibers in the solvent for the modifying agent before mixing the fibers and solvent with the modifying agent. In embodiments, the method further includes heating a mixture of the fibers, the modifying agent, and the solvent for the modifying agent.

[0139] The choice of modifying agent can affect the rate of the modification reaction. Therefore, the modifying agent can be selected, in combination with the reaction time and temperature, to provide a desired increase in the amount of chemical modification of the polymer constituting the fiber, such as polyvinyl alcohol, a copolymer of vinyl acetate and vinyl alcohol, or an anionic modified vinyl alcohol copolymer. In embodiments where modification is carried out by transesterification catalyzed with an ester or amide acid or base, the reaction rate can be modified based on the nucleophilic strength of the modifying agent.

[0140] Chemical modification can generally be any desired chemical modification of the functional groups of the polymer backbone of a fiber to a desired functional group. Non-limiting examples of chemical modifications to be attempted include one or more of esterification, amidation, amination, carboxylation, nitration, acyloin condensation, allylation, acetylation, imidation, halogenation, sulfonation, alkylation, acetalization, enolization, nitrosation, silane coupling, and crosslinking. In embodiments, the method may include mixing a polymer containing at least one vinyl acetate moiety or vinyl alcohol moiety, for example, at least one vinyl acetate moiety alone, at least one vinyl alcohol moiety alone, or both vinyl acetate and vinyl alcohol moieties, under conditions sufficient to chemically modify, the chemical modification including one or more of esterification, amidation, amination, carboxylation, nitration, acyloin condensation, allylation, acetylation, imidation, halogenation, sulfonation, alkylation, acetalization, enolation, nitrosation, and silane coupling. In embodiments, the method may include contacting the polymer under conditions sufficient to crosslink, the modifier including corona treatment, electron beam emission, or UV emission. In some embodiments, the polymer after chemical modification is not crosslinked.

[0141] Modifiers can generally be any agent that can chemically modify the functional groups of a polymer backbone to desired functional groups and / or catalyze this process. Non-limiting examples of modifiers include, but are not limited to, anhydrides, carboxylic acids, alcohols, esters, ethers, sulfonic acids, sulfonates, click chemistry reagents, amides, amines, lactams, nitriles, ketones, allyl compounds, acetyl compounds, halogen compounds, alkyl-containing compounds, imides, acetal-containing compounds, enolates, nitro-containing compounds, silanes, aziridines, isocyanates, or any combination thereof. In embodiments, modifiers include anhydrides, carboxylic acids, alcohols, esters, ethers, sulfonic acids, sulfonates, click chemistry reagents, amides, amines, nitriles, ketones, allyl compounds, acetyl-containing compounds, halogen-containing compounds, alkyl-containing compounds, imides, acetal-containing compounds, enolates, nitro-containing compounds, silanes, aziridines, isocyanates, energy sources, or any combination thereof. In the embodiments, the denaturing agent includes an anhydride, an amine, a sulfonate, a sulfonic acid, a monocarboxylic acid, a dicarboxylic acid, or any combination thereof. In the embodiments, the denaturing agent includes a sulfonate. In the embodiments, the sulfonate includes aminopropyl sulfonate. In the embodiments, the denaturing agent includes an amine or a lactam. In the embodiments, the lactam includes pyrrolidone or caprolactam. In the embodiments, the denaturing agent includes a sulfonic acid. In the embodiments, the sulfonic acid includes 2-acrylamido-2-methylpropanesulfonic acid (AMPS). In the embodiments, the denaturing agent includes a monocarboxylic acid or a dicarboxylic acid.In the embodiments, the monocarboxylic acid or dicarboxylic acid includes acetic acid, maleic acid, monoalkyl maleic acid, dialkyl maleic acid, fumaric acid, monoalkyl fumaric acid, dialkyl fumaric acid, itaconic acid, monoalkyl itaconic acid, dialkyl itaconic acid, citraconic acid, monoalkyl citraconic acid, dialkyl citraconic acid, mesaconic acid, monoalkyl mesaconic acid, dialkyl mesaconic acid, glutaconic acid, monoalkyl glutaconic acid, dialkyl glutaconic acid, alkyl (alkyl) acrylates, the alkali metal salts mentioned above, their hydrolyzed alkali metal salts, their esters, or combinations thereof. In the embodiments, the denaturing agent includes an anhydride. In the embodiments, the anhydride is an organic acid anhydride, and the organic acid anhydride includes acetic acid anhydride, propionic acid anhydride, isobutyric acid anhydride, maleic acid anhydride, phthalic acid anhydride, glutaric acid anhydride, itaconic acid anhydride, citraconic acid anhydride, glutaconic acid anhydride, or any combination thereof. In some embodiments, the organic acid anhydride includes maleic acid anhydride. In some embodiments, the modifying agent includes aziridine. In some embodiments, the aziridine is an oligomer. In some embodiments, the modifying agent includes isocyanate. In some embodiments, the isocyanate is an oligomer. In some embodiments, the starting fiber includes a copolymer of vinyl acetate and vinyl alcohol, and the modifying agent includes an organic acid anhydride. The hydroxyl groups (-OH) from the vinyl alcohol moiety react with the modifying agent, chemically bonding and attaching to the modified portion on the polymer chain. In certain cases, the degree of modification is the same as (equal to) the degree of hydrolysis of the unmodified polymer when the hydroxyl groups have completely reacted.

[0142] As used herein, the term “click chemistry reagent” refers to a reagent that chemically modifies the polymer backbone of a fiber to form the first functional group of a click chemistry reactive pair. As used herein, the term “click chemistry reactive pair” refers to a pair of complementary functional groups capable of undergoing a click chemistry reaction. As used herein, “first functional group of a click chemistry reactive pair” refers to one of a pair of complementary functional groups capable of undergoing a click chemistry reaction. Generally, there are four main classes of click chemistry reactions: 1) cycloaddition, 2) nucleophilic ring-opening, 3) non-aldol type carbonyl chemistry, and 4) addition to carbon-carbon multiple bonds. A click chemistry reaction pair can be a pair of complementary functional groups compatible with the four classes of click chemistry reactions shown above, such as thiol / alkene, azide / alkyne, azide / alkene, alkene / tetrazine, isonitrile / tetrazine, etc. Further examples of click chemistry reaction pairs can be found in Wang et al., Pharm Res., 2008, 25(10): 2216-2230; Bowman et al., Adv. Funct. Mater., 2014, 24, 2572-2590; and Jozwiak et al., Chem. Rev., 2013, 113, 4905-4979.

[0143] Generally, the reaction rate increases as the concentration of the modifying agent in the solvent for the modifying agent increases. Therefore, the concentration of the modifying agent can be selected in combination with the reaction time, reaction temperature, and selection of the modifying agent to bring about a desired increase in the degree of modification of the polymer constituting the fiber, such as polyvinyl alcohol, polyvinyl alcohol copolymer, or modified polyvinyl alcohol copolymer. Generally, the concentration of the modifying agent in the solvent for the modifying agent can be any concentration. Typically, the concentration will be selected so that all of the provided modifying agent is in solution. In embodiments, the modifying agent may be provided in amounts from about 0.2% to about 75% (w / w) based on the weight of the solvent, for example, from about 0.2% to about 75%, from about 0.2% to about 50%, from about 0.2% to about 25%, from about 0.5% to about 20%, from about 1% to about 18%, from about 2% to about 16%, from about 5% to about 15%, from about 8% to about 12%, or about 10%. In embodiments, the modifying agent is provided in an amount of about 0.2% to about 25% (w / w) based on the weight of the solvent. In embodiments, the modifying agent is provided in an amount of about 2% to about 25% (w / w) based on the weight of the solvent. In embodiments, the modifying agent is provided in an amount of about 5% to about 15% (w / w) based on the weight of the solvent. In embodiments where the modifying agent is an energy source, generally, the reaction rate increases as the intensity of the energy source increases. Therefore, the energy intensity can be selected in combination with the reaction time, reaction temperature, and selection of the modifying agent to result in a desired increase in the degree of modification of the polymer constituting the fiber, such as polyvinyl alcohol.

[0144] The solvent for the modifying agent can generally be any solvent in which the modifying agent is soluble and the fiber being treated is insoluble for the duration of contact with the solvent at the temperature in which the treatment is performed. In embodiments, the fiber is insoluble in the solvent before treatment. In embodiments, the fiber is insoluble in the solvent during treatment. In embodiments, the fiber is insoluble in the solvent after treatment. Generally, the solvent can be selected in combination with the reaction time, reaction temperature, selection of the modifying agent and its concentration to produce a desired increase in the degree of modification of the polymer constituting the fiber, e.g., polyvinyl alcohol. As the polarity of the solvent increases, the diffusion of the solvent into the polymer matrix of the fiber generally increases, and consequently, the diffusion of the modifying agent into the polymer matrix increases. While not strictly theoretical, it is thought that as the polarity of the solvent increases, the degree of modification of the inner / core section of the fiber can increase, and therefore the degree of modification can increase across the cross-section of the fiber. Furthermore, although not strictly theoretical, as the polarity of the solvent decreases, the diffusion of the solvent into the polymer matrix of the fiber generally decreases, and therefore the degree of modification may increase in portions of the fiber surface / exterior / sheath. Modification of the fiber polymer in portions of the fiber surface / exterior / sheath also results in an average increase in the degree of modification across the cross-section of the fiber. Furthermore, although not strictly theoretical, a combination of solvents can be used to provide a diffusion-controlled radial gradient of the degree of modification of the polymer of the treated fiber. In embodiments, the combination of solvents can be a two-phase solvent system. In embodiments, the two-phase solvent system may include water and an organic solvent. In embodiments, the two-phase solvent system may include water and an alcohol (e.g., methanol, ethanol, isopropanol, butanol, pentanol). In embodiments, the two-phase solvent system includes water and methanol.

[0145] In an embodiment, the solvent for the denaturant can be characterized by Hansen solubility parameters (HSP). Without being bound by theory, the three HSP values of dispersion, molar volume, and hydrogen bonding are considered to be indicators of the miscibility of polyvinyl alcohol and thus solvation or swelling by a particular solvent. Further, without being bound by theory, hydrogen bonding is the greatest predictor among the expected behaviors, but H, which is the sum of all parameters total is also considered to be predictive. Generally, when the HSP value of the solvent is lower than the HSP value of polyvinyl alcohol, the greater the difference in HSP values between the solvent and polyvinyl alcohol, the lower the diffusion rate of the solvent into the polyvinyl alcohol. Without being bound by theory, the H total value of the solvent total is about 4 to about 15 units lower than the H total value of polyvinyl alcohol, the solvent uptake rate and the diffusion rate of the solvent into the polyvinyl alcohol are such that a gradient of solvent uptake, and thus denaturant uptake, occurs, and a gradient of the degree of denaturation of the polyvinyl alcohol fibers across the cross-section is provided, with a higher degree of denaturation in the surface region compared to the inner core region. Without being bound by theory, the H total value of the solvent total is about 4 to about 15 units higher than the H total value of the polyvinyl alcohol of the fiber, the solvent uptake rate and the diffusion rate of the solvent into the polyvinyl alcohol are such that solvent uptake, and thus uptake of the denaturant, occurs rapidly, and a uniform degree of denaturation is provided across the cross-section of the polyvinyl alcohol fibers. Further, without being bound by theory, the H total value of the solvent total is more than 15 units lower than the H

[0146] value of the polyvinyl alcohol of the fiber, the diffusion rate is limited such that only the outer surface of the fiber is treated with the denaturant, and when the H

[0146] value of the solvent is more than 15 units higher than the H

[0146] value of the polyvinyl alcohol of the fiber, the solvent is considered to dissolve the polyvinyl alcohol of the fiber.In the embodiment, the solvent for the denaturant includes a polar solvent. In the embodiment, the solvent includes octanol, heptanol, hexanol, pentanol, butanol, propanol, tetrahydrofuran, dichloromethane, acetone, ethanol, N-methylpyrrolidone, methanol, acetonitrile, ethylene glycol, N,N-dimethylformamide, glycerol, dimethyl sulfoxide, formic acid, water, or any combination thereof. In the embodiment, the solvent includes n-octanol, n-heptanol, n-hexanol, n-pentanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-propanol, isopropanol, acetone, ethanol, N-methylpyrrolidone, methanol, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, water, or any combination thereof. In embodiments, the solvent includes n-propanol, acetone, ethanol, N-methylpyrrolidone, methanol, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, water, or any combination thereof. In embodiments, the solvent includes one or more solvents selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, acetone, N-methylpyrrolidone, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, water, and any combination thereof. In embodiments, the solvent includes an alcohol that is liquid under mixed conditions. In embodiments, the solvent includes methanol. In embodiments, the solvent includes methanol and at least one additional solvent. In embodiments, the solvent includes methanol and water. In embodiments, the solvent includes at least one of butanol, pentanol, hexanol, heptanol, and octanol in combination with water. In embodiments, the solvent includes a mixture of a first solvent and a second solvent. In embodiments, the first solvent includes water and the second solvent includes an alcohol. In the embodiment, the second solvent includes methanol, ethanol, n-propanol, isopropanol, or any combination thereof. In the embodiment, the solvent includes DMSO and water.In the embodiment, the solvent comprises DMSO and water, provided in a weight ratio of approximately 40 / 60 to 80 / 20. While not strictly theoretical, it is thought that as the amount of water increases beyond 60% or the amount of DMSO increases beyond approximately 80%, the interaction of each solvent with polyvinyl alcohol increases, resulting in increased polymer expansion and gelation.

[0147] In the embodiments, the solvent includes a nonpolar solvent. In the embodiments, the solvent includes hexane, cyclohexane, methylpentane, pentane, cyclopropane, dioxane, benzene, pyridine, xylene, toluene, diethyl ether, chloroform, or a combination thereof.

[0148] In the embodiment, the solvent comprises a mixture of a first solvent and a second solvent. In the embodiment, the first solvent comprises a polar solvent, and the second solvent comprises a nonpolar solvent. In the embodiment, the first solvent has a first dielectric constant, and the second solvent has a second dielectric constant, with the dielectric constant of the first solvent being higher than that of the second solvent. In the embodiment, the first dielectric constant is 5 or less, 4 or less, 3 or less, or 2 or less. In the embodiment, the second dielectric constant is greater than 5, greater than 7.5, greater than 10, greater than 15, greater than 18, greater than 20, greater than 25, or greater than 30. In the embodiment, the difference between the first dielectric constant and the second dielectric constant is at least 3, at least 5, at least 8, or at least 10. In embodiments where the solvent comprises a mixture of a first solvent and a second solvent, the first and second solvents may be provided in any ratio, provided that the hydrolyzing agent is soluble in the mixture, and the fibers are insoluble in the mixture before, during, and after treatment. In embodiments, the first and second solvents may be provided in weight ratios of about 99 / 1 to about 1 / 99, about 95 / 5 to about 5 / 95, about 90 / 10 to about 10 / 90, about 85 / 15 to about 15 / 85, about 80 / 20 to about 20 / 80, about 75 / 25 to about 25 / 75, about 70 / 30 to about 30 / 70, about 65 / 35 to about 35 / 65, about 60 / 40 to about 40 / 60, about 55 / 45 to about 45 / 55, or about 50 / 50.

[0149] In embodiments, the method of the present disclosure further comprises mixing a fiber, a modifier, and optionally a solvent with an activator. The activator can generally be any additive that facilitates the treatment of the fiber with the modifier. The activator can generally include a catalyst for reducing the activation energy of the reaction between the polymer of the fiber and the modifier, or a compound that facilitates the diffusion of the modifier into the polymer matrix, for example. In embodiments, the activator can include an acid, a base, an aziridine, a free radical initiator, or a combination thereof. In embodiments, the activator is a free radical initiator. In embodiments, the free radical initiator can include a peroxide. In embodiments, the peroxide can include benzoic peroxide, hydrogen peroxide, dibenzoyl peroxide (BPO), didodecanoyl (dilauroyl) peroxide (LPO), or a combination thereof. In embodiments, the free radical initiator can include an azo compound, for example, 2,2'-azobisisobutyronitrile (AIBN). In embodiments, the activator is an acid. In embodiments, the acid can include an organic acid, an inorganic acid, or a combination thereof. In the embodiment, the organic acid may include carboxylic acids such as formic acid, acetic acid, oxalic acid, malonic acid, or a combination thereof. In the embodiment, the inorganic acid may include boric acid, nitric acid, nitrite, phosphoric acid, phosphorous acid, sulfuric acid, hydrosulfide, hydrochloric acid, chlorous acid, hypochlorous acid, hydrohalogens, or a combination thereof. In the embodiment, the hydrohalogens may include hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, or a combination thereof. In the embodiment, the activator is a base. In the embodiment, the base may include a metal hydroxide. In the embodiment, the metal hydroxide may include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, or a combination thereof.

[0150] Modified fibers can generally be fibers that have undergone chemical modification after mixing with a modifying agent. Non-limiting examples of chemical modifications that modified fibers may contain include monocarboxylic acids, dicarboxylic acids, sulfonic acids, sulfonates, first functional groups of click chemistry reactive pairs, amides, amines, carbamates, nitriles, ketones, esters, allyls, acetyls, halogens, alkyls, imides, acetals, enolates, nitros, silanes, crosslinks, or any combination thereof. In embodiments, modified fibers may contain monocarboxylic acids, dicarboxylic acids, sulfonic acids, sulfonates, first functional groups of click chemistry reactive pairs, amides, amines, nitriles, ketones, esters, allyls, acetyls, halogens, alkyls, imides, acetals, enolates, nitros, silanes, or any combination thereof. In embodiments, modified fibers may contain sulfonates, sulfonic acids, or both. In embodiments, the modified fiber includes vinyl sulfonic acid, allyl sulfonic acid, ethylene sulfonic acid, 2-acrylamide-1-methylpropanesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, 2-methacrylamide-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, the aforementioned alkali metal salt derivatives, or combinations thereof. In embodiments, the modified fiber includes a sulfonate. In embodiments, the sulfonate includes aminopropyl sulfonate. In embodiments, the modified fiber includes a sulfonic acid. In embodiments, the sulfonic acid includes 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and / or the sodium salt of AMPS. In embodiments, the modified fiber includes an amine or carbamate as a portion from a lactam. In embodiments, such a carbamate may be derived from a lactam containing pyrrolidone or caprolactam. In embodiments, the modified fiber includes a monocarboxylic acid or dicarboxylic acid.In embodiments, the monocarboxylic acid or dicarboxylic acid includes acetic acid, maleic acid, monoalkyl maleic acid, dialkyl maleic acid, fumaric acid, monoalkyl fumaric acid, dialkyl fumaric acid, itaconic acid, monoalkyl itaconic acid, dialkyl itaconic acid, citraconic acid, monoalkyl citraconic acid, dialkyl citraconic acid, mesaconic acid, monoalkyl mesaconic acid, dialkyl mesaconic acid, glutaconic acid, monoalkyl glutaconic acid, dialkyl glutaconic acid, alkyl (alkyl) acrylates, the alkali metal salts described above, their hydrolyzed alkali metal salts, their esters, or combinations thereof. In embodiments, the dicarboxylic acid includes monomethyl maleic acid. In embodiments, the modified fiber contains a first functional group of the click chemistry reactive pair, as disclosed above. In embodiments, the modified fiber contains a first functional group of the click chemistry reactive pair, and the activators disclosed herein contain a second functional group of the click chemistry reactive pair. Therefore, the modifying agent can be intended to modify the fiber with a specific first functional group of the click chemistry reactive pair, and thus a desired activator containing a second functional group of the click chemistry reactive pair can readily react with the modified fiber to form a fiber bound to the desired activator. In embodiments, the modified fiber contains an amide. In embodiments, the modified fiber contains an ester. In embodiments, the modified fiber contains an amine.

[0151] Generally, the increase in the amount of chemical modification (degree of modification) of the modified fibers compared to the fibers before the processing method disclosed herein can range from 0.1 mol% to about 50 mol%. For example, the degree of modification from the methods disclosed herein can range from about 1 mol%, about 2 mol%, about 3 mol%, about 4 mol%, about 5 mol%, about 6 mol%, about 7 mol%, about 8 mol%, about 9 mol%, about 10 mol%, about 11 mol%, about 12 mol%, about 13 mol%, about 14 mol%, about 15 mol%, about 20 mol%, about 30 mol%, about 40 mol%, or about 50 mol%, for example, from 1 mol% to 15 mol%, about 1 mol% to about 10 mol%, about 1 mol% to about 8 mol%, about 2 mol% to about 8 mol%, about 2 mol% to about 8 mol%, about 3 mol% to about 8 mol%, about 3 mol% to about 6 mol%, or about 1 mol% to about 4 mol%.

[0152] Reaction conditions can also be selected to design and control the solubility mechanism and / or absorbency and retention of the treated fibers. For example, reaction conditions can be selected to provide fibers having a cross-section characterized by: (a) a core-sheath structure in which the sheath polymer is different from the core polymer, e.g., has a greater degree of modification (Figure 2A); (b) a radial gradient of the degree of modification of the polymer from the interior region to the surface region, e.g., to increase the degree of modification (Figure 2B; Figure 3); or (c) a consistent degree of modification across the cross-section (Figure 2C). The resulting fibers may have different solubility mechanisms (e.g., immediate release, delayed release, or evoked release), chemical compatibility / resistance, and / or absorbency and retention properties. Reaction conditions that can be modified to provide a controlled fiber structure include the selection of the modifier, the selection of the concentration of the modifier in the solvent for the modifier, the reaction (contact or mixing) time, the reaction (contact or mixing) temperature, the selection of the solvent for the modifier solution, and the optional inclusion of an activator.

[0153] Fibers having a core-sheath or core-shell structure can be prepared by treating a fiber having a polymer such as polyvinyl alcohol with a modifier and a solvent under conditions sufficient to minimize the radial diffusion of the solvent and modifier into the inner core region of the fiber. Diffusion of the solvent and modifier into the inner core region of the fiber can be minimized, for example, by selecting a short reaction time, a low reaction temperature, and / or including a nonpolar solvent. In embodiments, the contact of the method of the present disclosure is carried out under conditions sufficient to provide a fiber having a polymer having a vinyl alcohol portion having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer. In embodiments, conditions sufficient to provide a fiber having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer include including a solvent having a dielectric constant of 20 or less, 18 or less, 14 or less, or 10 or less. In embodiments, sufficient conditions to provide a fiber having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer include mixing the fiber and the modifier solution at temperatures ranging from about 10°C to about 30°C, about 10°C to about 25°C, or about 15°C to about 25°C. In embodiments, sufficient conditions to provide a fiber having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer include mixing the fiber and the modifier for about 2 minutes to about 6 hours, about 2 minutes to about 4 hours, about 5 minutes to about 3 hours, about 10 minutes to about 2 hours, or about 15 minutes to about 1 hour.In embodiments, sufficient conditions to provide a fiber having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer include: including a solvent having a dielectric constant of 20 or less, 18 or less, 14 or less, or 10 or less; mixing the fiber, modifier, and solvent at temperatures ranging from about 10°C to about 30°C, about 10°C to about 25°C, or about 15°C to about 25°C; and mixing the fiber, modifier, and solvent for about 2 minutes to about 6 hours, about 2 minutes to about 4 hours, about 5 minutes to about 3 hours, about 10 minutes to about 2 hours, or about 15 minutes to about 1 hour. Such fibers having a cross-section characterized by a core-sheath structure in which the sheath polymer has a greater degree of modification than the core polymer can provide delayed release properties of activators provided inside the fiber, controlled release properties of activators conjugated to the modified polymer, induced release of activators provided inside the fiber and / or conjugated to the modified polymer, and / or high chemical resistance compared to unmodified fibers. In embodiments, the modified sheath region can be substantially continuous. As used herein, unless otherwise specified, “substantially continuous” means a homogeneous distribution of modification across the entire surface area of ​​the fiber such that at least about 60% of the fiber's surface area contains modification. In embodiments, at least about 75%, at least about 80%, at least about 90%, or at least about 95% of the fiber's surface area contains modification. Not bound by theory, it is believed that if the modified sheath region is substantially continuous, the fiber can demonstrate high chemical resistance when in contact with irritating chemicals such as oxidizing agents, and thus the fiber will be protected from discoloration and loss of solubility. Furthermore, although not strictly adhering to theory, the discontinuous regions within the modified sheath area are considered to be areas susceptible to the effects of irritating chemicals, where, when the fibers come into contact with these chemicals, there is a possibility of penetration of the irritating chemicals and deterioration of the fibers over time due to these chemicals.

[0154] As used herein, unless otherwise specified, “delayed release” of activators from fibers means that the entire activator is not immediately released from the fiber when it comes into contact with a solvent (usually water) under the conditions of the fiber’s final use. For example, a fiber containing an activator and used for laundry may not immediately release the entire active substance under washing conditions. Rather, the active substance may diffuse from the fiber over time. As used herein, unless otherwise specified, “induced release” of activators from fibers means that the active substance is not released from the fiber at all until induced conditions are met. For example, a fiber containing an activator and used for laundry may not release the activator until the wash water reaches a certain temperature and / or pH.

[0155] Inducing conditions, though not limited to them, may include temperature, pH, UV / VIS radiation, IR radiation, the presence of ions, the presence of catalysts, or a combination thereof.

[0156] As the thickness of the sheath structure increases, the stability of the fiber with a fluid-expanded and saturated core increases, but the amount of available polymer in the core for fluid absorption decreases. The sheath thickness can be controlled by controlling the diffusion of a modifier into the polymer structure of the fiber. Since the treatment of the inner portion of the fiber is diffusion-controlled, it is understood that the sheath may have thickness variation around the outer edge of the fiber, and the inner portion of the sheath may have a lower degree of modification of the polymer at the outer surface of the sheath but a higher degree of modification of the polymer at the center of the fiber. Therefore, in some embodiments, the cross-section of the fiber may be characterized by a core-sheath structure and may also be characterized by having an increasing gradient from the inner portion to the outer portion of the fiber.

[0157] Fibers having a cross-section characterized by an increasing radial gradient structure can be prepared by treating fibers having a polymer such as polyvinyl alcohol or vinyl acetate and vinyl alcohol copolymer with a degree of modification, under conditions sufficient to alter the radial diffusion of the solvent and modifier into the inner region of the fiber. In embodiments, fibers having a cross-section characterized by an increasing radial gradient structure from the inner region to the outer region can be prepared by using a number of solvents having different diffusion rates (simultaneous or stepwise), varying the temperature during mixing to alter the diffusion rates of the solvent and modifier into the fiber, and / or selecting a reaction time that is long enough to allow some of the modifier to diffuse into the inner region and alter the degree of modification of the polymer, but not long enough to allow the polymer in the inner portion to be chemically modified to the same extent as the polymer in the outer / surface portion. In embodiments, the mixing of the method of the present disclosure is carried out under conditions sufficient to provide fibers having a cross-section characterized by an increasing gradient of the degree of modification of the polymer from the inner region to the surface region of the fiber. Such fibers having a cross-section characterized by an increasing gradient of modification can provide delayed release properties of activators provided within the fiber, induced release of activators provided within the fiber, increased absorption capacity compared to fibers having a consistent degree of modification across the cross-section, and / or improved retention of absorbent fluids.

[0158] Fibers having a cross-section characterized by a core-sheath structure and / or increasing radial structure may have an activator filled in the core / inner region. The active material may fill the core / inner region by bringing the fiber into contact with a solution of the activator and allowing the activator solution to diffuse into the polymer structure, resulting in the core / inner region of the fiber absorbing the activator solution and expanding. The activator may be any activator disclosed herein that is soluble in the solvent of the activator solution. The solvent may be any solvent disclosed herein. Without intending to be bound by theory, it is assumed that the diffusion rate into the core / inner region of the fiber increases as the polarity of the solvent increases. An exemplary solvent is water, however, the water in the activator solution is maintained at a temperature lower than the dissolution temperature of the polymer constituting the core / inner region of the fiber and the sheath / shell / outer region of the fiber.

[0159] Fibers having a cross-section characterized by a polymer having the same degree of modification across the entire cross-section can be prepared by treating fibers having a polymer such as polyvinyl alcohol or polyvinyl alcohol copolymer with a modifying agent and a solvent under conditions sufficient to maximize the radial diffusion of the solvent and modifying agent into the inner core region of the fiber. Diffusion of the solvent and modifying agent into the inner core region of the fiber can be maximized, for example, by selecting a long reaction time, a high reaction temperature, and / or including a highly polar solvent. In embodiments, the mixing of the method of the present disclosure is carried out under conditions sufficient to provide fibers having a cross-section characterized by the polymer having the same degree of modification across the cross-section.

[0160] Advantageously, in some embodiments, although not bound by theory, as the degree of polymer modification in the surface region of the fiber increases compared to the degree of polymer modification in the inner region of the fiber (if any), the bulk solubility of the fiber can increase or be maintained at the same level, making it possible to more precisely tune the fiber solubility parameters and different solubility characteristics of the fiber compared to simply selecting fibers with a consistent degree of modification throughout or without modification.

[0161] This disclosure further provides a method for processing fibers, comprising contacting the surface of a fiber containing a polymer comprising at least one vinyl acetate portion or vinyl alcohol portion, for example, only at least one vinyl acetate portion, only at least one vinyl alcohol portion, or both vinyl acetate and vinyl alcohol portions, with a modifying agent and a solvent for the modifying agent to chemically modify at least a portion of the polymer having the modifying agent in a region of the fiber including at least the surface of the fiber. In embodiments, contact can be carried out by dipping, spraying, transfer coating, water absorption, foaming, brushing, roll coating, humidification, vapor deposition, printing or a combination thereof. In embodiments, the polymer is selected from the group consisting of polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, modified polyvinyl alcohol copolymers, or combinations thereof. The modifying agent may include any modifying agent disclosed herein, and the solvent for the modifying agent may include any solvent disclosed herein. In embodiments, the method further includes contacting the surface of a fiber with a modifying agent after the fiber has been formed, as part of a continuous in-line process. For example, a fiber may be formed from a polymer mixture at a first station and then transferred to a second station where the surface of the fiber may be treated. In another example, the fibers can be processed in an apparatus that includes a fiber supply station, a fiber processing station, and a fiber collection station. In the embodiment, the fibers are in motion during contact with the fiber surface. In the embodiment, contact of the fiber surface with the modifier and solvent is carried out in a batch process or a continuous in-line process. For example, the fibers can be prepared in bulk and treated with a modifier before forming the fibers into a nonwoven web. In the embodiment, the fibers include staple fibers, staple yarns, fiber fills, needle-punched cloths, bonded fibers, or combinations thereof. In the embodiment, the fibers include staple fibers. In the embodiment, the method further includes washing and drying the fibers after contacting the fiber surface with the modifier. Washing may be by rinsing the fibers with a non-solvent. A non-solvent refers to a liquid that removes unreacted chemicals such as modifiers without solubilizing the fibers. Examples of non-solvents include either polar or non-polar solvents.For example, acetone can be used. Drying of the fibers may be done by air jet drying, agitation, vortexing, or centrifugation.

[0162] In embodiments, the method disclosed herein for processing fibers comprises a polymer having a degree of hydrolysis in the range of about 79% to about 99.9%, for example, 88%, 92%, or 96%, a modifying agent comprising maleic anhydride, and a solvent comprising methanol, and the method further comprises mixing an activator comprising sodium hydroxide with the fibers, modifying agent and solvent.

[0163] This disclosure provides fibers processed according to the methods of this disclosure.

[0164] This disclosure provides fibers having a surface region and an internal region. The fibers include a polymer comprising at least one vinyl acetate portion or a vinyl alcohol portion, for example, at least one vinyl acetate portion only, at least one vinyl alcohol portion only, or both vinyl acetate and vinyl alcohol portions, which is chemically modified with a modifier as described herein. The polymer in the fiber is chemically modified with a modifier and chemically bonded to the modifier portion, for example, through a reaction with a hydroxyl group in the vinyl alcohol portion. In embodiments, the fiber has a cross-section comprising an internal region having a first degree of modification and a surface region having a second degree of modification, which is different from, for example, greater than, the first degree of modification of the polymer in the internal region. The first degree of modification may be zero or greater than zero. When the first degree of modification is zero, the internal region of the fiber includes a polymer that is unmodified, comprising at least one vinyl acetate portion or vinyl alcohol portion, for example, at least one vinyl acetate portion only, at least one vinyl alcohol portion only, or both vinyl acetate and vinyl alcohol portions, such as polyvinyl alcohol, polyvinyl alcohol copolymer, anionic modified polyvinyl alcohol copolymer, or a combination thereof. In embodiments, the disclosure provides a fiber having a surface region and an internal region. In embodiments, the fiber comprises a polymer comprising vinyl acetate and vinyl alcohol portions modified with a modifying agent. The fiber has a cross-section comprising an internal region having a first degree of modification and a surface region having a second degree of modification greater than the first degree of modification.

[0165] The fibers of the present disclosure may have a cross-section of the fiber having an increasing gradient of the degree of polymer modification from the interior region to the surface region. In embodiments, the fibers of the present disclosure may have a cross-section of the fiber having the same degree of polymer modification from the interior region to the surface region. In some embodiments, the polymer before modification includes polyvinyl alcohol, a copolymer of vinyl acetate and vinyl alcohol, an anionic modified polyvinyl alcohol copolymer, or a combination thereof. After modification, the polymer chemically bonds with the modifying agent moiety through a reaction between the hydroxyl groups in the vinyl alcohol and the modifying agent.

[0166] As shown in Figure 3, the present disclosure provides a fiber including a cross-section having a core-sheath structure or a core-shell structure. The fiber includes a first region, e.g., a core region (indicated as 401 in Figure 3), which includes a polymer comprising at least one vinyl acetate portion or vinyl alcohol portion, for example, only at least one vinyl acetate portion, only at least one vinyl alcohol portion, or both vinyl acetate and vinyl alcohol portions. Such polymer in the core region is unmodified or has a first degree of modification by a modifying agent. The first degree of modification can be zero or greater than zero. The fiber also includes a second region, e.g., a sheath region (indicated as 402 in Figure 3), which includes such polymer that is modified with a modifying agent and has a second degree of modification greater than the first degree of modification with respect to the polymer in the first region. In embodiments, the fiber may include a cross-section having a core-sheath structure. The fiber comprises a first region, e.g., a core region, containing polyvinyl alcohol or a polyvinyl alcohol copolymer, and a second region, e.g., a sheath region, containing such polymer modified to a second degree of modification different from a first degree of modification in the first region. In embodiments, the fiber may include a cross-section having a core-sheath structure. The fiber comprises a first region, e.g., a core region, containing polyvinyl alcohol or a polyvinyl alcohol copolymer, and a second region, e.g., a sheath region, containing such polymer having a second degree of modification greater than a first degree of modification of the polymer in the first region. In some embodiments, the polyvinyl alcohol copolymer is a copolymer of vinyl acetate and vinyl alcohol before modification. The polymer in the fiber is chemically modified with a modifier and chemically bonded at the modifier portion, for example, through a reaction with the hydroxyl groups of the vinyl alcohol portion. In the embodiment, the fibers further include at least one third region, for example, at least one intermediate region (indicated as 403 in Figure 3), which is located between the first region and the second region and contains a polymer having a third degree of modification intermediate between a first degree of modification of the polymer in the first region and a second degree of modification of the polymer in the second region.In embodiments, the fiber further includes at least one third region, for example, at least one intermediate region (indicated as 403 in Figure 3), which is located between a first region and a second region and contains a polymer having a third degree of modification greater than the first degree of modification of the first region and less than the second degree of modification of the second region. In embodiments, the fiber may include a plurality of third intermediate regions, for example, a plurality of intermediate regions (indicated as 403a, 403b in Figure 3), located between the first region and the second region. The cross-section of the fiber has an increasing gradient in the degree of modification of the polymer from the first region to the second region. In embodiments, the plurality of third regions contain polymers modified from polyvinyl alcohol or polyvinyl alcohol copolymer with a modifying agent. The cross-section of the fiber has an increasing gradient in the degree of modification of the polymer from the first region to the second region.

[0167] In embodiments, the fibers of the present disclosure may have differences in the degree of polymer modification between the first and second regions, for example, 0.1% to 15%, 0.3% to 10%, 0.5% to 8%, 1% to 8%, 2% to 5%, 1% to 4%, or 0.5% to 5%, ranging from about 0.1% to 15%, 0.3% to 10%, 0.5% to 8%, 1% to 8%, 2% to 5%, 1% to 4%, or 0.5% to 5%. In the embodiment, the cross-section of the fiber can be characterized by the average radius, and the second region is approximately 0.5% of the average radius of the fiber, for example, approximately 1%, 2%, 3%, 5%, 7%, 9%, 10%, 12%, 15%, 20%, 25%, 50%, 75%, 80%, 85%, 90%, 92%, 94%, 96%, or 98%, for example, from approximately 1% to approximately 98%. These could constitute a range of approximately 1% to 90%, approximately 1% to 75%, approximately 1% to 50%, approximately 1% to 25%, approximately 1% to 20%, approximately 1% to 15%, approximately 1% to 12%, approximately 1% to 10%, approximately 1% to 8%, approximately 1% to 6%, approximately 1% to 5%, approximately 1% to 4%, approximately 2% to 25%, approximately 4% to 25%, approximately 6% to 35%, or approximately 8% to 20%.

[0168] In the embodiment, the polymers in the first, second, and optionally third regions have the same degree of polymerization. In the embodiment, the polymers in the first, second, and optionally third regions may have the same degree of hydrolysis.

[0169] While it is stated that fibers disclosed herein, having a cross-section characterized by a core-sheath structure or gradient degree of modification, have a greater degree of modification in the sheath and / or surface regions of the fiber, it is understood that fibers can be prepared such that the degree of modification of the polymer in the sheath and / or surface regions of the fiber is lower than the degree of modification of the polymer in the core and / or inner surface region. Accordingly, this disclosure further provides fibers having a surface region and an internal region. The fiber comprises a polymer chemically modified with a modifier, comprising at least one vinyl acetate portion or vinyl alcohol portion, for example, at least one vinyl acetate portion only, at least one vinyl alcohol portion only, or both vinyl acetate and vinyl alcohol portions. The fiber has a cross-section that includes a surface region having a lower degree of modification than the degree of modification in the internal region. In embodiments, this disclosure provides fibers having a surface region and an internal region. The fiber comprises a vinyl alcohol and polyvinyl alcohol copolymer. The fiber has a cross-section that includes a polymer in the surface region having a lower degree of modification than the degree of modification in the internal region.

[0170] The fibers of the present disclosure may have a cross-section having a decreasing gradient in the degree of polymer modification from the internal region to the surface region. In embodiments, the fibers of the present disclosure may have a cross-section having a decreasing gradient in the degree of polyvinyl alcohol copolymer modification from the internal region to the surface region.

[0171] Nonwoven web

[0172] The nonwoven webs of this disclosure are generally sheet-like structures having two outer surfaces, and the nonwoven webs contain a plurality of fibers. As used herein, unless otherwise specified, the “outer surfaces” of the nonwoven web mean the surfaces of the sheet-like structure shown as 100 and 101 in Figure 5. A nonwoven web generally refers to an arrangement of fibers bonded together, and the fibers are neither woven nor knitted. Generally, the plurality of fibers can be arranged in any orientation. In embodiments, the plurality of fibers are arranged randomly (i.e., without orientation). In embodiments, the plurality of fibers are arranged in a unidirectional orientation. In embodiments, the plurality of fibers are arranged in a bidirectional orientation. In some embodiments, the plurality of fibers are multidirectional, having different arrangements in different regions of the nonwoven web. In embodiments, the nonwoven web may contain a single type of water-soluble fiber. In embodiments, the nonwoven web may contain a single type of water-insoluble fiber. In some embodiments, the nonwoven web may comprise a single type of water-soluble fiber and one or more different types of water-insoluble fiber. In some embodiments, the nonwoven web may comprise one or more different types of water-soluble fiber and one or more different types of water-insoluble fiber. In some embodiments, the nonwoven web may consist of, or be essentially composed of, water-soluble fiber. In some embodiments, the nonwoven web may consist of, or be essentially composed of, water-insoluble fiber. In some embodiments, the nonwoven web may comprise a single type of fiber-forming material (i.e., all fibers have a fiber-forming material of the same composition), but may also comprise fibers prepared by one or more fiber-forming methods, e.g., wet-cooled gel spinning, thermoplastic fiber spinning, meltblown, spunbond, or a combination thereof. In some embodiments, the nonwoven web may comprise a single type of fiber-forming material, and the fibers are produced from a single fiber-forming method.In some embodiments, the nonwoven web may contain two or more fiber-forming materials (e.g., a blend of fibers having fiber-forming materials of different compositions, a fiber containing a blend of fiber-forming materials, or both), and the fibers may be prepared by one or more fiber-forming methods, e.g., wet-cooled gel spinning, thermoplastic fiber spinning, meltblown, spunbond, or a combination thereof. In some embodiments, the nonwoven web may contain two or more fiber-forming materials, and the fibers are produced from a single fiber-forming method. In embodiments, the fibers of the nonwoven web may have substantially the same or different diameters.

[0173] In embodiments of the nonwoven web of the present disclosure, which includes a fiber blend comprising first and second fibers, the first and second fibers are characterized by their length-to-diameter ratio (L / D ratio), toughness, shape, stiffness, elasticity, solubility, melting point, and glass transition temperature (T). g ), may have differences in fiber-forming material, color, or combinations thereof.

[0174] As is well understood in the art, the term machining direction (MD) refers to the direction in which a web progresses when a nonwoven web is manufactured in, for example, a commercially available nonwoven fabric manufacturing machine. Similarly, the term cross direction (CD) refers to the plane direction of the web perpendicular to the machining direction. With respect to nonwoven composite articles, wipes, absorbent articles, or other articles including nonwoven composite articles of the present disclosure, these terms refer to the corresponding directions of the article with respect to the nonwoven web used in the manufacture of the article.

[0175] The toughness of a nonwoven web may be the same as or different from the toughness of the fibers used to prepare the web. Without intending to be bound by theory, the toughness of a nonwoven web is considered to be related to the strength of the nonwoven web, with higher toughness resulting in greater strength. Generally, the toughness of a nonwoven web can be modified by using fibers with different toughness. The toughness of a nonwoven web can also be affected by processing. Generally, the water-dispersible webs of this disclosure may have relatively high toughness, i.e., water-dispersible nonwoven webs are self-supporting webs that can be used as standalone materials for preparing articles and / or pouches. In embodiments, the nonwoven web is a self-supporting web. Conversely, nonwoven webs prepared by meltblown, electrospinning and / or spun spinning methods typically have low toughness and may not be self-supporting or usable as standalone webs for forming articles or pouches. Therefore, in some embodiments, the nonwoven web is not self-supporting and is used in combination with a second nonwoven web and / or a water-soluble film.

[0176] In embodiments, the nonwoven webs of the present disclosure may have a ratio of toughness in the machining direction to toughness in the cross direction (MD:CD) in the range of about 0.5 to about 1.5, about 0.75 to about 1.5, about 0.80 to about 1.25, about 0.90 to about 1.1, or about 0.95 to about 1.05, or about 1. In embodiments, the nonwoven webs of the present disclosure have a toughness ratio MD:CD of about 0.8 to about 1.25. In embodiments, the nonwoven webs of the present disclosure have a toughness ratio MD:CD of about 0.9 to about 1.1. In embodiments, the nonwoven webs of the present disclosure have a toughness of about 1. Without intending to be bound by theory, it is believed that as the toughness ratio MD:CD approaches 1, the durability of the nonwoven increases, providing superior resistance to degradation of the nonwoven when stress is applied to the nonwoven during use, for example, by rubbing with a water-soluble wipe containing the nonwoven web of the present disclosure, or by tensile stress (pulling / tugging) of the nonwoven caused by movement during wear of a wearable absorbent article.

[0177] The nonwoven webs of this disclosure have a rougher surface compared to water-soluble films, thereby reducing contact between the surface and the nonwoven web compared to contact between the surface and the water-soluble film. Advantageously, this surface roughness can improve the consumer's feel (i.e., a cloth-like feel rather than a rubbery feel), improve aesthetics (i.e., less gloss than water-soluble films), and / or facilitate processability in the preparation of thermoformed and / or vertically formed, filled and sealed and / or multi-chambered packets where the web needs to be stretched along the surface of a processing machine / mold. Therefore, the fibers must be rough enough to impart surface roughness to the resulting nonwoven web without becoming rough enough to create resistance.

[0178] Nonwoven webs can be characterized by their basis weight. The basis weight of a nonwoven is the mass per unit area of ​​the nonwoven. As is known in the art, the basis weight can be modified by changing the manufacturing conditions. A nonwoven web may have the same basis weight before and after bonding. Alternatively, the basis weight of a nonwoven web may change depending on the bonding method. For example, if bonding occurs by the application of heat and pressure, the thickness of the nonwoven (and therefore the area of ​​the nonwoven) may decrease, thereby increasing the basis weight. In another example, bonding between fibers can also be induced during an aeration process at a suitable temperature, for example, in the range of about 100°C to about 200°C (e.g., 120°C to 180°C). Therefore, as used herein, unless otherwise specified, the basis weight of a nonwoven refers to the basis weight of the nonwoven after bonding.

[0179] The nonwoven web disclosed herein has a density of approximately 0.1 g / m². 2 ~about 700g / m 2 , about 0.5g / m 2 ~about 600g / m 2 , about 1g / m 2 ~about 500g / m 2 , about 1g / m 2 ~about 400g / m 2 , about 1g / m 2 ~about 300g / m 2 , about 1g / m 2 ~about 200g / m 2, about 1g / m 2 ~about 100g / m 2 , about 30g / m 2 ~about 100g / m 2 , about 20g / m 2 ~about 100g / m 2 , about 20g / m 2 ~about 80g / m 2 Or approximately 25g / m 2 ~about 70g / m 2 It can have any basis weight within the range.

[0180] In the embodiment, the nonwoven web may be carted, at approximately 5 g / m². 2 ~about 15g / m 2 , about 7g / m 2 ~Approx. 13g / m 2 Approximately 9g / m 2 ~Approx. 11g / m 2 Or approximately 10g / m 2 It may have a basis weight of 30 g / m². In the embodiment, the nonwoven web may be carded, resulting in a basis weight of 30 g / m². 2 Or larger, for example, 30g / m 2 ~about 70g / m 2 , about 30g / m 2 ~about 60g / m 2 , about 30g / m 2 ~about 50g / m 2 , about 30g / m 2 ~about 40g / m 2 , or approximately 30g / m 2 ~Approx. 35g / m 2 It may have a basis weight in the range of [value]. In the embodiment, the nonwoven web may be melt-spun, about 1 g / m². 2 ~about 20g / m 2 , about 2g / m 2 ~about 15g / m 2 , about 3g / m 2 ~about 10g / m 2 , about 5g / m 2 ~about 15g / m 2 , about 7g / m 2 ~Approx. 13g / m 2 Approximately 9g / m 2 ~Approx. 11g / m 2 In the range of approximately 10 g / m². 2It may have a basis weight of approximately 0.1 g / m². In the embodiment, the nonwoven web may be melt-spun, resulting in a basis weight of approximately 0.1 g / m². 2 ~about 10g / m 2 , about 0.1g / m 2 ~about 8g / m 2 , about 0.2g / m 2 ~about 6g / m 2 , about 0.3g / m 2 ~approximately 4g / m 2 Approximately 0.4 g / m 2 ~about 2g / m 2 , or approximately 0.5 g / m 2 ~about 1g / m 2 It may have a basis weight of [a certain amount].

[0181] Basis weight is related to the fiber volume density and porosity of the nonwoven fabric. During preparation and before bonding, the nonwoven web has a fiber density of approximately 30% by volume or less; that is, for a given volume of nonwoven fabric, 30% or less of the volume consists of fibers, and the remaining volume is air. Therefore, the nonwoven web is highly porous. The fiber volume density and porosity of a nonwoven fabric are inversely correlated properties; for example, a nonwoven fabric with a fiber volume density of approximately 30% by volume will have a porosity of approximately 70% by volume. It is well understood in the art that porosity decreases as fiber volume density increases. Fiber volume density can be increased by increasing the basis weight of the nonwoven fabric, for example, by bonding through the application of heat and pressure or by high-temperature ventilation, which can potentially reduce the thickness (and therefore volume) of the nonwoven fabric. Therefore, as used herein, unless otherwise specified, the fiber volume density and porosity of a nonwoven fabric refer to the fiber volume density and porosity of the nonwoven fabric after bonding.

[0182] The nonwoven webs of the present disclosure may have porosity ranging from about 50% to about 95%, for example, at least about 50%, at least about 60%, at least about 70%, at least about 75%, or at least about 80% and up to about 95%, up to about 90%, up to about 85%, up to about 80%, up to about 75%, up to about 70%, or any porosity ranging from about 50% to about 95%, about 50% to about 80%, about 50% to about 70%, about 60% to about 75%, about 60% to about 80%, about 60% to about 90%, about 75% to about 85%, about 75% to about 90%, or about 75% to about 95%.

[0183] Pore ​​sizes, while not limited to these, can be determined using high-magnification regular surface analysis techniques, including Brunauer-Emmett-Taylor theory (BET), small-angle X-ray scattering (SAXS), and molecular adsorption.

[0184] The nonwoven webs of the present disclosure may have any thickness. Preferred thicknesses, but are not limited to, include about 5 to about 10,000 μm (1 cm), about 5 to about 5,000 μm, about 5 to about 1,000 μm, about 5 to about 500 μm, about 200 to about 500 μm, about 5 to about 200 μm, about 20 to about 100 μm, or about 40 to about 90 μm, or about 50 to 80 μm, or about 60 to 65 μm, for example, 50 μm, 65 μm, 76 μm, or 88 μm. The nonwoven webs of the present disclosure may be characterized by high loft or low loft. Generally, loft refers to the ratio of thickness to basis weight. High-loft nonwoven webs can be characterized by a high ratio of thickness to basis weight. As used herein, “high loft” means a nonwoven web of the present disclosure having a basis weight and a thickness greater than 200 μm as defined herein. The thickness of a nonwoven web can be determined according to ASTM D5729-97, ASTM D5736 and ISO 9073-2:1995, which may include, for example, placing the nonwoven web under a 2N load and measuring its thickness. High loft materials can be used according to methods known in the art, e.g., air-through bonding, or cross-wrapping, which involves folding an unbonded web over itself using a cross-wrapper to create loft and basis weight. Without intending to be bound by theory, the solubility of a nonwoven web containing water-soluble fibers is considered to be independent of the web's thickness, in contrast to water-soluble films where the solubility of the film may depend on the film's thickness. In this regard, the basis weight is considered to be the parameter that limits the reach of water to the fibers, and thereby the dissolution of the fibers in a water-soluble nonwoven web, because, regardless of the film's thickness, individual fibers provide a larger surface area than in water-soluble films.

[0185] The water solubility of nonwoven webs in this disclosure is a function of the type of fiber(s) used to prepare the web and the basis weight of the water-dispersible web. While not strictly theoretical, for nonwoven webs containing a single fiber type and a single fiber-forming material, the solubility profile of the nonwoven web follows the same solubility profile as the fiber(s) used to prepare the web, and the solubility profile of the fiber follows the same solubility profile as the fiber-forming polymer(s) from which the fiber is prepared. For example, in the case of nonwoven webs containing PVOH fibers, the degree of hydrolysis and modification of the PVOH or PVOH copolymer can be selected so that the water solubility of the nonwoven web is also affected. Generally, at a given temperature, the water solubility of the polymer generally increases as the degree of modification of the PVOH or PVOH copolymer increases.

[0186] Modification of PVOH or PVOH copolymers increases the solubility of the polymer. Therefore, at a given temperature, the solubility of a water-dispersible nonwoven web prepared from a modified PVOH copolymer is expected to be higher than that of a nonwoven web prepared from an unmodified PVOH copolymer and having the same degree of hydrolysis as the PVOH copolymer. Furthermore, at a given temperature, the solubility of a water-dispersible nonwoven web prepared from a PVOH copolymer or a modified PVOH copolymer treated by the methods described herein to increase the degree of fiber modification is expected to be higher than that of a nonwoven web prepared without fiber modification as disclosed herein. Following these trends, water-dispersible nonwoven webs with specific solubility characteristics can be designed. In some embodiments, the water solubility of the fibers is maintained after modification with a modifying agent, and the water solubility of the fibers may be substantially the same before and after chemical modification with a modifying agent.

[0187] Surprisingly, in the case of nonwoven webs containing blends of fiber types, each having a single fiber-forming material, the solubility of the nonwoven web does not follow the rules of mixtures as expected for blends of fiber types. Rather, in the case of nonwoven webs containing blends of two fiber types, if the two fiber types are provided in a ratio other than 1:1, the solubility of the nonwoven tends to gravitate towards the solubility of the less soluble fiber (i.e., fiber that requires higher temperatures to dissolve completely and dissolves more slowly at temperatures below its complete dissolution temperature). In the case of nonwoven webs containing a 1:1 blend of fibers, the solubility of the nonwoven web was generally lower than that of nonwoven webs containing blends other than 1:1 (i.e., at a given temperature, nonwoven webs containing a 1:1 blend took longer to break, disintegrate, and dissolve than nonwoven webs containing, for example, 3:1 and 1:3 ratios of fiber types). This tendency was particularly pronounced at temperatures below the complete dissolution temperature of the less soluble fibers.

[0188] The inclusion of water-insoluble fibers in a nonwoven web can also be used to design nonwoven webs with specific solubility and / or delayed release properties (e.g., when the nonwoven web is contained in a water-dispersible pouch). Without intending to be bound by theory, it is generally assumed that as the weight percentage (based on the total weight of the nonwoven web) of water-insoluble fibers contained in the nonwoven web increases, the solubility of the nonwoven web generally decreases, and the delayed release properties of the pouch containing the nonwoven web generally increase. Upon contact with water at or above the dissolution temperature of water-soluble fibers, a nonwoven web containing water-soluble and water-insoluble fibers begins to thin as the water-soluble fibers dissolve, thereby causing the web structure to decompose and / or increasing the pore size of the pores in the nonwoven web. Generally, the greater the decomposition of the web structure or the increase in pore size, the faster water reaches the contents of the pouch and the faster the contents of the pouch are released. Similarly, delayed release of contents of a pouch containing a nonwoven web of the present disclosure can be achieved by using a blend of water-soluble fibers having different solubility properties and / or different dissolution temperatures. Generally, in the case of a nonwoven web containing water-soluble fibers including a polyvinyl alcohol fiber-forming material, at a water temperature of 50% or higher than the complete dissolution temperature of the water-soluble fibers (for example, 40°C for fibers with a complete dissolution temperature of 70°C), the fibers undergo expansion and softening of the polymer network, but the entire structure remains intact. In embodiments in which the nonwoven web contains both water-soluble and water-insoluble fibers, the ratio of soluble fibers to insoluble fibers is not particularly limited. Water-soluble fibers may constitute approximately 1% to 99% by weight, 20% to 80% by weight, 40% to 90% by weight, 50% to 90% by weight, or 60% to 90% by weight of the total weight of the fibers, while water-insoluble fibers may constitute approximately 1% to 99% by weight, 20% to 80% by weight, 10% to 60% by weight, 10% to 50% by weight, or 10% to 40% by weight of the total weight of the fibers.

[0189] Furthermore, as the basis weight of the nonwoven web increases, the dissolution rate of the web decreases, provided that the fiber composition and bonding parameters remain constant as more material dissolves. For example, at a given temperature, a water-soluble web prepared from fibers containing PVOH polymer(s), having a basis weight of, for example, 40 g / m 2 is expected to dissolve more slowly than an otherwise identical nonwoven web having a basis weight of, for example, 30 g / m 2 . This relationship was particularly pronounced when the temperature of the water for dissolution was lower than the complete dissolution temperature of the fibers constituting the nonwoven web. Thus, the basis weight can also be used to modify the dissolution characteristics of the water-dispersible nonwoven web. The nonwoven web generally has a basis weight in the range of about 1 g / m 2 to about 700 g / m 2 , about 1 g / m 2 to about 600 g / m 2 , about 1 g / m 2 to about 500 g / m 2 , about 1 g / m 2 to about 400 g / m 2 , about 1 g / m 2 to about 300 g / m 2 , about 1 g / m 2 to about 200 g / m 2 , about 1 g / m 2 to about 100 g / m 2 , about 30 g / m 2 to about 100 g / m 2 , about 20 g / m 2 to about 100 g / m 2 , about 20 g / m 2 to about 80 g / m 2 , about 25 g / m 2 to about 70 g / m 2 , or about 30 g / m 2 to about 70 g / m1] 2 and can have any basis weight in the ranges listed.

[0190] Furthermore, the calendering setting has a secondary effect on the solubility profile of the nonwoven webs of this disclosure. For example, for nonwoven webs having the same fiber chemistry and similar basis weight, the dissolution time of the nonwoven web generally increases with increasing calendering temperature at a given calendering pressure. This relationship was particularly pronounced when the temperature of the water for dissolution was lower than the complete dissolution temperature of the fibers constituting the nonwoven web.

[0191] Without intending to be bound by theory, it is expected that the solubility of water-soluble nonwoven webs (e.g., in terms of time to dissolution, according to MSTM-205) will exceed that of water-soluble films of the same size (L×W) and / or mass prepared from the same PVOH polymer. This is due to the larger surface area found in nonwovens compared to films, which results in faster dissolution.

[0192] The nonwoven webs of this disclosure may include any auxiliary agents disclosed herein. The auxiliary agents may be dispersed throughout the web, for example, between fibers, or applied to one or more surfaces of the nonwoven web. As is well known in the art, the auxiliary agents can be added to the nonwoven web during the melt-spun process using the “co-forming” method developed by Kimberly Clark. The auxiliary agents may also be added to one or more surfaces of the nonwoven web or articles prepared therefrom by any preferred means.

[0193] In embodiments, the nonwoven webs of the present disclosure are substantially free of additives. As used herein, unless otherwise specified, “substantially free of additives” means that the nonwoven web contains less than about 0.01 wt%, less than about 0.005 wt.%, or less than about 0.001 wt.%, of additives based on the total weight of the nonwoven web.

[0194] In one embodiment, one or more stationary powder spray guns are used to direct a stream of auxiliary powder onto a web or article from one or more directions, while the web or article is transported through a coating zone by a belt conveyor. In an alternative embodiment, the article is transported through a suspension of auxiliary powder in the air. In yet another alternative embodiment, the article is tumble-mixed with the auxiliary powder in a cylindrical device. In another embodiment, which can be combined with any other embodiment, electrostatic force is used to enhance the attraction between the auxiliary powder and the article. This type of process may be based on negatively charging the powder particles and directing these charged particles toward the grounded article. In other alternative embodiments, but not limited to these, the auxiliary powder is applied to the article by a secondary transfer tool including a rotating brush in contact with the powder, or by a powdering glove that can transfer the powder from a container to the article. In yet another embodiment, the auxiliary powder is applied by dissolving or suspending the powder in a non-aqueous solvent or carrier, and then spraying and spraying this onto a nonwoven fabric or article. In one embodiment, the solvent or carrier then evaporates, leaving the auxiliary powder behind. In one class of embodiments, the auxiliary powder is applied to the nonwoven fabric or article in a precise input amount. This class of embodiments utilizes a closed-system dry lubricant application apparatus, such as the PekuTECH powder application apparatus PM 700D. In this process, the auxiliary powder is supplied to the application apparatus's feed trough, either in batches or continuously as needed. The nonwoven web or article is transferred from the outlet belt of a standard rotary drum pouch apparatus onto the conveyor belt of the powder application apparatus, where a controlled input amount of the auxiliary is applied to the nonwoven web or article.

[0195] Liquid additives can be applied to nonwoven webs or articles by, for example, spin casting, spraying of a solution such as an aerosolized solution, roll coating, flow coating, curtain coating, extrusion, knife coating, or a combination thereof.

[0196] In embodiments, nonwoven webs may be colored with pigments and / or dyes to provide improved aesthetic effects compared to water-soluble films. Suitable colorants may include indicator dyes, e.g., pH indicators (e.g., thymol blue, bromothymol, thymolphthalein, and thymolphthalein), water / water indicators (e.g., hydrochromic inks or leuco dyes), or thermochromic inks, which change color as the temperature rises and / or falls. Suitable colorants, but not limited to, include triphenylmethane dyes, azo dyes, anthraquinone dyes, perylene dyes, indigoid dyes, food, drug and cosmetic (FD&C) colorants, organic pigments, inorganic pigments, or combinations thereof. Examples of colorants include, but are not limited to, FD&C Red #40, Red #3, FD&C Black #3, Black #2, mica-based pearlescent pigments, FD&C Yellow #6, Green #3, Blue #1, Blue #2, Titanium Dioxide (food grade), Brilliant Black, and combinations thereof.

[0197] When included in water-soluble fibers, the colorant may be provided in amounts of 0.01% to 25% by weight of the water-soluble polymer mixture, for example, 0.02% by weight, 0.05% by weight, 0.1% by weight, 0.5% by weight, 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, and 24% by weight of the water-soluble polymer mixture.

[0198] Advantageously, the nonwoven webs of the present disclosure may exhibit preferential shrinkage in the presence of heat and / or water (e.g., humidity). Therefore, the nonwoven webs may shrink in heat and / or water when formed into packets. Further advantageously, the nonwoven webs of the present disclosure may exhibit increased toughness (i.e., mechanical properties) and improved solubility performance after storage in a high-temperature and high-humidity environment (e.g., 38°C and 80% relative humidity (RH)). Such an increase in toughness and improvement in solubility performance is surprising, as predictions based on compositionally similar water-soluble films would not suggest that toughness and solubility performance are affected by storage under high-temperature and high-humidity conditions. In particular, after removal of an equivalent water-soluble film from a controlled environment, the water-soluble film re-equilibrium with the surrounding environment without causing long-term or permanent changes in the film's performance properties.

[0199] The nonwoven webs of the present disclosure can be used as a single layer or can be layered with other nonwoven webs and / or water-soluble films. In some embodiments, the nonwoven web comprises a single layer of nonwoven web. In some embodiments, the nonwoven web is a multilayer nonwoven web comprising two or more layers of nonwoven web. One or more layers can be laminated to one another. In improvements of the embodiments described above, two or more layers may be the same (e.g., they may be prepared from the same fibers and have the same basis weight). In improvements of the embodiments described above, two or more layers may be different (e.g., they may be prepared from different types of fibers and / or have different basis weights). In embodiments, the nonwoven web can be laminated to a water-soluble film. In improvements of the embodiments described above, the nonwoven web and the water-soluble film may be prepared from the same polymer (e.g., a PVOH copolymer, a modified polymer, having a specific viscosity, degree of hydrolysis, and, in the case of a modified polymer, a degree of modification). In improvements to the embodiments described above, nonwoven webs and water-soluble films can be prepared from different polymers (for example, the polymer used to prepare the fibers of the nonwoven web may have different fiber chemistry (e.g., modification), viscosity, degree of polymerization, degree of hydrolysis, and / or solubility) than the polymer constituting the water-soluble film). Advantageously, multilayer nonwoven webs and laminates can be used to adjust the water vapor transmission rate (MVTR) of pouches or packets made therefrom. Multilayer materials can be prepared according to various processes known in the art, such as melt extrusion, coating (e.g., solvent coating, aqueous coating, or solid coating), spray bonding, material transfer, hot lamination, cold lamination, and combinations thereof.

[0200] A multilayer nonwoven web may have a basis weight that is the sum of the basis weights of its individual layers. Therefore, a multilayer nonwoven web takes longer to dissolve than any of the individual layers provided as single layers. In embodiments, the multilayer nonwoven has a basis weight of approximately 1 g / m². 2 ~about 100g / m 2It can have a basis weight in the range of [range]. Furthermore, without intending to be bound by theory, if the pore size and pore arrangement configuration are heterogeneous between layers, the pores in each layer will not be aligned, thereby providing a multilayer nonwoven web with pores smaller than those in the individual layers. Therefore, a non-porous water-dispersible nonwoven web can be prepared by layering multiple porous water-dispersible nonwoven webs.

[0201] Nonwoven webs can also be laminated to water-soluble films. Lamination can be formed using any method known in the art, including, but not limited to, heat and pressure, high-temperature ventilation, chemical bonding and / or solvent welding. Chemical bonding may involve functionalizing the surface of the nonwoven web and / or the surface of the water-soluble film by ionic or covalent bonds, and a chemical reaction may occur when the surface of the nonwoven web comes into contact with the surface of the water-soluble film, covalently bonding the nonwoven web and the water-soluble film together. Multilayer nonwoven webs may comprise three or more layers. In embodiments, a multilayer nonwoven web may comprise a first layer comprising a water-soluble film, a second layer comprising a nonwoven web, and a third layer comprising a water-soluble film.

[0202] Advantageously, the laminate can be prepared simultaneously with pouch formation by bonding the nonwoven web and water-soluble film layer together, for example, using heat applied during thermoforming. The water-soluble film may have the same solubility and / or chemical compatibility characteristics as the nonwoven web, or it may have different solubility and / or chemical compatibility characteristics than the nonwoven web. In some embodiments, the water-soluble film has the same solubility and / or chemical compatibility characteristics as the nonwoven web. In some embodiments, the water-soluble film has different solubility and / or chemical compatibility characteristics than the nonwoven web. Advantageously, if the water-soluble film has different solubility and / or chemical compatibility characteristics than the nonwoven web, the laminate can be used to form a pouch having an inner surface with a first solubility and / or chemical compatibility, and an outer surface with a second solubility and / or chemical compatibility.

[0203] The water-soluble film used for lamination can generally be any water-soluble film, for example, one already known in the art. The polymer used to form the water-soluble film can be any water-soluble polymer or a combination thereof, for example, those described herein. The water-soluble film may contain at least about 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.%, or 90 wt.% and / or up to about 60 wt.%, 70 wt.%, 80 wt.%, 90 wt.%, 95 wt.%, or 99 wt.% of a water-soluble polymer, for example, a PVOH polymer, for example, a PVOH copolymer, for example, a polymer modified with a modifier, or any blend of these polymers.

[0204] The water-soluble film may contain, in amounts suitable for its intended purpose, other auxiliary and processing agents, such as, but not limited to, plasticizers, plasticizer compatibilizers, surfactants, lubricants, release agents, fillers, bulking agents, crosslinking agents, antiblocking agents, antioxidants, detackeners, defoaming agents, nanoparticles such as layered silicate nanoclay (e.g., sodium montmorillonite), bleaching agents (e.g., sodium metabisulfite, sodium bisulfite, or others), bittering agents (e.g., denatonium salts such as denatonium benzoate, denatonium sugars, and denatonium chloride; sucrose octaacetate; quinine; flavonoids such as quercetin and naringenin; and cassinoids such as casin and brucine), and pungent agents (e.g., capsaicin, piperine, allyl isocyanate, and resiniferatoxin), as well as other functional components. Embodiments containing plasticizers are preferred. The amount of such agents, individually or collectively, may be up to approximately 50 wt.%, 20 wt%, 15 wt%, 10 wt%, 5 wt.%, 4 wt%, and / or at least 0.01 wt.%, 0.1 wt%, 1 wt%, or 5 wt% of the film.

[0205] This disclosure further provides a method for processing a nonwoven web comprising a plurality of fibers comprising a polymer containing at least one vinyl acetate portion or a vinyl alcohol portion. The method comprises contacting at least a portion of the nonwoven web with a modifying agent and a solvent to chemically modify the polymer in the region of each fiber within it with the modifying agent, or to increase the degree of modification of the polymer of the fibers in that portion of the nonwoven web. The method provides a modified nonwoven web. In embodiments, the portion of the nonwoven web that is contacted with the modifying agent may be a surface of the nonwoven web. In embodiments, contact is obtained by dipping, spraying, transfer coating, water absorption, foaming, brushing, roll coating, humidification, vapor deposition, printing, or any combination thereof. In embodiments, contact is performed simultaneously with bonding the plurality of fibers to form a nonwoven web. In embodiments, contact and bonding include chemical bonding. In embodiments, contact and bonding include a thermally activated catalyst. A polymer comprising at least one vinyl acetate moiety or vinyl alcohol moiety may be a polyvinyl acetate homopolymer, a polyvinyl alcohol homopolymer, a polyvinyl alcohol copolymer, a modified polyvinyl alcohol copolymer, or any combination thereof, as disclosed herein. In embodiments, the polymer is selected from polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, modified polyvinyl alcohol copolymers, and any combination thereof. In embodiments, the polyvinyl alcohol copolymer is a copolymer of vinyl acetate and vinyl alcohol. In embodiments, the polyvinyl alcohol copolymer includes an anionically modified copolymer. In embodiments, the anionically modified copolymer includes a carboxylate, a sulfonate, or a combination thereof. In embodiments, the fiber further comprises additional polymers. The modifier may be any modification disclosed herein.In embodiments, the modifying agent may include anhydrides, carboxylic acids, alcohols, esters, ethers, sulfonic acids, sulfonates, click chemistry reagents, amides, amines, lactams, nitriles, ketones, allyl compounds, acetyl-containing compounds, halogen-containing compounds, alkyl-containing compounds, imides, acetal-containing compounds, enolates, nitros, silanes, aziridines, isocyanates, or combinations thereof. In embodiments, the modifying agent may include anhydrides. Examples of suitable anhydrides are given above. In embodiments, the modifying agent is provided in an amount from about 0.2% to about 75% (w / w) based on the weight of the solvent. In embodiments, the fibers are insoluble in the solvent before, during, and after treatment. In embodiments, the modifying agent further includes activators described herein.

[0206] This disclosure further provides nonwoven webs processed according to the methods of this disclosure. This disclosure provides nonwoven webs comprising a plurality of fibers as described herein. This disclosure provides multilayer nonwoven webs comprising a first layer, comprising a nonwoven web processed according to the methods of this disclosure or a nonwoven web comprising a plurality of fibers of this disclosure. The polymer of the fibers in the nonwoven web is chemically modified, for example, by bonding with a modifier portion through a chemical reaction, for example, a reaction between the hydroxyl group (-OH) of the vinyl alcohol portion and the modifier.

[0207] biodegradable

[0208] Polyvinyl alcohol polymers are generally biodegradable, as they decompose under aerobic, anaerobic, soil and compost conditions (in the presence of water), and in the presence of water and enzymes. Generally, the biodegradation activity of polyvinyl alcohol polymers increases as the degree of hydrolysis of the polymer increases by up to approximately 80%. Without intending to be bound by theory, it is thought that an increase in the degree of hydrolysis beyond 80% does not have a noticeable effect on biodegradability. Furthermore, the stereoregularity of the hydroxyl groups of polyvinyl alcohol polymers has a significant effect on the level of biodegradation activity, with the more isotactic the hydroxyl groups in the polymer sequence, the higher the decomposition activity. Without intending to be bound by theory, it is thought that, for soil and / or compost biodegradation, nonwoven webs prepared from polyvinyl alcohol fibers have a higher level of biodegradation activity compared to water-soluble films prepared from similar polyvinyl alcohol polymers, due to the increased polymer surface area provided by the nonwoven web compared to films. Furthermore, without intending to be bound by theory, it is thought that the degree of polymerization of polyvinyl alcohol polymers has little to no effect on the biodegradability of films or nonwoven webs prepared with the polymers, while the polymerization temperature can affect the crystallinity and aggregation state of the polymers, and therefore the polymerization temperature may have an effect on the biodegradability of the films or nonwovens. In particular, as the crystallinity decreases, the hydroxyl groups of the polymer chains become less aligned in the polymer structure, the polymer chains become more irregular, and the chains can accumulate as amorphous aggregates, thereby reducing the availability of regular polymer structures, and it is expected that the biodegradation activity will decrease for soil and / or compost biodegradation mechanisms in which the polymer does not dissolve.While not strictly adhering to theory, the stereoregularity of the hydroxyl groups in polyvinyl alcohol polymers has a significant effect on the level of biodegradation activity. Therefore, substitution of functional groups other than hydroxyl groups (e.g., anionic AMPS functional groups, carboxylate groups, or lactone groups), such as modifiers, is expected to lower the level of biodegradation activity compared to polyvinyl alcohol copolymers that are unmodified and have the same degree of hydrolysis, unless the functional group itself is also biodegradable and the biodegradability of the polymer can be increased by the substitution. Furthermore, although the biodegradation activity level of substituted polyvinyl alcohol may be lower than that of the corresponding homopolymer, the substituted polyvinyl alcohol is still expected to exhibit biodegradability.

[0209] Methods for determining biodegradable activity are known in the art, for example, as described in Chiellini et al., Progress in Polymer Science, Volume 28, Issue 6, 2003, pp. 963-1014, which is incorporated herein by reference in its entirety. Further methods and standards can be found in ECHA's Annex XV Restriction Report - Microplastics, Version number 1, January 11, 2019, which is incorporated herein by reference in its entirety. Preferred standards include OECD 301B (easily biodegradable), OECD 301B (enhanced biodegradability), OECD 302B (inherent biodegradability), OECD 311 (anaerobic), and ASTM D5988 (soil).

[0210] In embodiments, the fibers and nonwoven webs of this disclosure may be readily biodegradable, enhanced biodegradable, or inherently biodegradable according to the standards. As used herein, the term “easily biodegradable” means that the material (e.g., fiber) reaches 60% biodegradation (mineralization) within 28 days from the start of the test, according to the OECD 301B test as described in ECHA's Annex XV. As used herein, the term “enhanced biodegradation” means that the material (e.g., fiber) reaches 60% biodegradation within 60 days from the start of the test, according to the OECD 301B test as described in ECHA's Annex XV. In embodiments, the fibers and nonwoven webs of this disclosure meet the readily biodegradable standard. In embodiments, the fibers and nonwoven webs of this disclosure meet the readily biodegradable or enhanced biodegradable standard. In embodiments, the fibers and nonwoven webs of this disclosure meet the inherent biodegradation standard. In embodiments, the fibers and nonwoven webs of this disclosure meet the enhanced biodegradation standard. In embodiments, the fibers and nonwoven webs of the Disclosure meet the standards of inherent degradation, enhanced degradation, or easy degradation. In embodiments, the laminates (nonwovens and films) of the Disclosure meet the standards of easy degradation or enhanced degradation. use

[0211] The nonwoven webs of the present disclosure are suitable for a variety of commercial applications. Suitable commercial applications of the nonwoven webs of the present disclosure include, but are not limited to, water-dispersible or water-flushable pouches and packets; medical use, e.g., surgical masks, medical packaging, shoe covers, wound dressings and drug delivery; filtration systems for gasoline and petroleum, ore dressing, vacuum bags, air filters and allergen membranes or laminates; personal care products for body wipes, makeup remover wipes, exfoliating cloths and cosmetic tools, and wearable absorbent articles, e.g., diapers and adult incontinence products; office supplies, e.g., shopping bags or envelopes; and others, e.g., eyeglass cleaning wipes, indoor cleaning wipes, potting materials for plants, antimicrobial wipes, agricultural seed strips, fabric softener sheets, clothing / laundry bags, food packaging, food care wipes, pet care wipes, polishing tools, dust removal and hand sanitizer.

[0212] Sealing pouch

[0213] This disclosure further provides a pouch comprising a nonwoven web according to this disclosure, in the form of a pouch defining an internal pouch volume. In some embodiments, the pouch may comprise a laminate comprising a water-soluble film and a nonwoven web according to this disclosure. The pouch may be a water-dispersible pouch, optionally a water-soluble pouch and / or a water-flushable pouch. This disclosure further provides a method for preparing a packet comprising a nonwoven web according to this disclosure, comprising the steps of forming the nonwoven web into the form of a pouch, filling the pouch with a composition to be enclosed, and sealing the pouch to form a packet. In some embodiments, the sealing may comprise heat sealing, solvent welding, adhesive sealing, or a combination thereof.

[0214] The nonwoven webs and laminates disclosed herein are useful for making encapsulated articles in the form of pouches that define an internal pouch volume containing a composition for release in an aqueous environment. An "encapsulated article" includes, for example, in embodiments where the compartment encapsulates a solid that off-gasses, a sealed compartment with vent holes as needed, but more generally is a completely sealed compartment.

[0215] The pouch may include a single compartment or multiple compartments. The pouch can be formed from two nonwoven webs or laminates sealed at an interface, or from a single nonwoven web or laminate folded over itself and sealed. The nonwoven web or laminate forms at least one sidewall of the pouch, optionally the entire pouch, and preferably the outer surface of at least one sidewall. In another type of embodiment, the nonwoven web or laminate forms the inner wall of a packet, for example, as a partition between compartments. The nonwoven web or laminate can also be used in combination with a water-soluble film, for example, as an outer wall, inner wall, and / or lid of a compartment.

[0216] The composition encapsulated in the pouch can include, for example, any of the various compositions described herein and is not particularly limited. In embodiments including multiple compartments, each compartment may contain the same and / or different compositions. Next, the composition can take any suitable form including, but not limited to, liquids, solids, gels, pastes, marls, compressed solids (tablets), and combinations thereof (e.g., solids suspended in a liquid).

[0217] In some embodiments, the pouch includes a plurality of compartments. The plurality of compartments are generally stacked such that the compartments share a partition wall within the pouch. The compartments of the multi-compartment pouch may be of the same or different sizes and / or volumes. The compartments of the multi-compartment pouch may be separated or joined in any suitable manner. In an embodiment, the second and / or third and / or subsequent compartments are stacked on top of the first compartment. In one embodiment, the third compartment may be stacked on top of the second compartment, which is then stacked on top of the first compartment in a sandwich configuration. Alternatively, the second and third compartments may be stacked on top of the first compartment. However, it is equally contemplated that the first, second and / or third and / or subsequent compartments may be oriented side-by-side or concentrically. The compartments may be packaged in strings where each compartment is individually separated by a cut line. Thus, each compartment may be individually separated from the remainder of the string by the end user. In some embodiments, the first compartment may be surrounded, at least in part, by the second compartment, such as in a tire and rim arrangement or a pouch-in-pouch arrangement.

[0218] The geometry of the compartments may be the same or different. In embodiments, each of the third and subsequent compartments as required has a different geometry and shape compared to the first and second compartments. In these embodiments, the third and subsequent compartments as required are arranged and configured in a design relative to the first or second compartment. The design may be used decoratively, educationally, or illustratively, for example to illustrate a concept or instruction and / or to indicate the origin of the product.

[0219] Method of making a pouch

[0220] Pouches and packets may be manufactured using any suitable equipment and methods. For example, a single-compartment pouch may be manufactured using vertical filling, horizontal filling, or rotary drum filling techniques commonly known in the art. Such processes may be continuous or intermittent. Nonwoven webs, layered nonwoven webs and films, or laminate structures may be moistened and / or heated to increase their malleability. The method may also include the use of vacuum to draw the nonwoven web, layered nonwoven web and film, or laminate structure into a suitable mold. The vacuum for drawing the nonwoven web or laminate into the mold may be applied for about 0.2 to about 5 seconds, or about 0.3 to about 3 seconds, or about 0.5 to about 1.5 seconds, after the nonwoven web, layered nonwoven web and film, or laminate structure is on the horizontal portion of the surface. This vacuum could, for example, provide a pressure range of 10 mbar to 1000 mbar, or 100 mbar to 600 mbar.

[0221] The molds from which packets may be produced may have any shape, length, width, and depth depending on the required dimensions of the pouch. The molds may also vary in size and shape from one another, if desired. For example, the volume of the final pouch may be approximately 5 ml to 300 ml, or approximately 10 ml to 150 ml, or approximately 20 ml to 100 ml, and the size of the molds will be adjusted accordingly.

[0222] thermoforming

[0223] Thermoformable nonwoven webs or laminates are those that can be formed through the application of heat and force. Thermoforming of nonwoven webs, layered nonwoven webs, and film or laminate structures is a process of heating the nonwoven web, layered nonwoven web, and film or laminate structure to form it (e.g., in a mold), and then cooling the resulting nonwoven web or laminate so that it retains its shape, e.g., the shape of the mold. Heat may be applied using preferred means. For example, the nonwoven web or laminate may be heated directly by passing it under a heating element or through hot air before or after it has been supplied onto a surface. Alternatively, the nonwoven web or laminate may be heated indirectly, for example by heating the surface or by applying a heat item onto the nonwoven web or laminate. In some embodiments, the nonwoven web or laminate is heated using infrared light. The nonwoven web or laminate may be heated to temperatures in the range of approximately 50°C to 200°C, approximately 50°C to 170°C, approximately 50°C to 150°C, approximately 50°C to 120°C, approximately 60°C to 130°C, approximately 70°C to 120°C, or approximately 60°C to 90°C. Thermoforming can be carried out by any one or more of the following processes: manual draping of the thermosoftened nonwoven web or laminate onto a mold; pressure induction forming (e.g., vacuum forming) of the softened nonwoven web or laminate onto a mold; automatic high-speed indexing of new extruded sheets at precisely known temperatures to a forming and trimming station; or automatic placement, plugging and / or air stretching and pressurizing of the nonwoven web or laminate.

[0224] Alternatively, the nonwoven web or laminate may be moistened by any suitable means, for example, directly by spraying a wetting agent (including water, polymer compositions, plasticizers for nonwoven webs or laminate compositions, or any combination thereof) onto the nonwoven web or laminate before or after it has been supplied onto the surface, or indirectly by moistening the surface or by applying a wet item onto the nonwoven web or laminate.

[0225] The nonwoven web or laminate, once heated and / or wetted, may be drawn into a suitable mold, preferably using a vacuum. Filling of the molded nonwoven web or laminate can be achieved by utilizing any suitable means. In embodiments, the most preferred method depends on the product form and the required filling rate. In embodiments, the molded nonwoven web or laminate is filled by in-line filling technology. The filled open packets are then closed using a second nonwoven web or laminate by any suitable method to form a pouch. This may be achieved during horizontal positioning and continuous constant movement. Closure may be achieved by continuously supplying a second nonwoven web or laminate, preferably a water-soluble nonwoven web or laminate, onto the open packets, and then preferably by sealing the first and second nonwoven webs or laminates together, typically in the area between molds, and therefore between packets.

[0226] Seal the pouch

[0227] Any preferred method for sealing the pouch and / or its individual compartments may be utilized. Non-limited examples of such means include heat sealing, solvent welding, solvent or wet sealing, and combinations thereof. Typically, only the area where the seal is to be formed is treated with heat or solvent. Heat or solvent may be applied by any means, typically to the sealing material, typically only to the area where the seal is to be formed. When solvent or wet sealing or welding is used, it may also be preferable to apply heat. Preferred wet or solvent sealing / welding methods include selectively applying a solvent to the areas between the mold or onto the sealing material, for example by spraying or printing it onto these areas and then applying pressure onto these areas to form the seal. For example, sealing rolls and belts (which also supply heat if necessary) can be used.

[0228] In embodiments, an inner nonwoven web or laminate is sealed to an outer nonwoven web(s) or laminate(s)(s) by solvent sealing. The sealing solution is generally an aqueous solution. In embodiments, the sealing solution contains water. In embodiments, the sealing solution contains water and further comprises one or more polyols, diols and / or glycols, e.g., 1,2-ethanediol (ethylene glycol), 1,3-propanediol, 1,2-propanediol, 1,4-butanediol (tetramethylene glycol), 1,5-pentanediol (1,5-pantanediol) (pentamethylene glycol), 1,6-hexanediol (hexamethylene glycol), 2,3-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, various polyethylene glycols (e.g., diethylene glycol, triethylene glycol) and combinations thereof. In the embodiment, the encapsulation solution includes erythritol, treitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fusitol, iditol, inositol, boremitol, isomal, maltitol, lactitol, or any combination thereof. In the embodiment, the encapsulation solution includes a water-soluble polymer.

[0229] The sealing solution can be applied to the interface region of the inner nonwoven web or laminate in any amount suitable for bonding the inner and outer nonwoven webs or laminates. As used herein, the term "coat weight" refers to the amount of sealing solution applied to the nonwoven web or laminate in grams of solution per square meter of nonwoven web or laminate. Generally, if the coat weight of the sealing solvent is too low, the nonwoven web or laminate will not adhere properly, increasing the risk of pouch defects at the seams. Furthermore, if the coat weight of the sealing solvent is too high, the risk of solvent migration from the interface region increases, increasing the probability that etch holes may form on the sides of the pouch. The coat weight window refers to the range of coat weights that can be applied to a given film while maintaining good adhesion and avoiding the formation of etch holes. A wide coat weight window is desirable because a wider window provides a robust seal under a wide range of operations. A suitable coat weight window is at least about 3 g / m². 2 , or at least about 4 g / m 2 , or at least about 5g / m 2 , or at least about 6 g / m 2 That is the case.

[0230] Packet disconnection

[0231] The formed packets may be cut by a cutting device. Cutting can be achieved using any known method. Cutting may also be preferably performed in a continuous manner, preferably at a constant speed, and preferably in a horizontal position. The cutting device may be, for example, a sharp item, or a thermal item, or a laser, in the latter case, a thermal item or laser "burns" through the film / sealing area.

[0232] Formation and filling of multi-compartment pouches

[0233] The different compartments of a multi-compartment pouch may be fabricated together in a side-by-side style or in a concentric style, and the resulting combined pouch may or may not be separated by cutting. Alternatively, the compartments may be fabricated separately.

[0234] In embodiments, the pouch may be manufactured according to a process comprising: a) forming a first compartment (as described above); b) forming a recess in or in all of the closed compartment formed in step (a) to produce a second molded compartment superimposed on the first compartment; c) filling and closing the second compartment with a third nonwoven web, laminate or film; d) sealing the first, second and third nonwoven webs, laminates or films; and e) cutting the nonwoven web or laminate to produce a multi-compartment pouch. The recess formed in step (b) may be achieved by applying a vacuum to the compartment prepared in step (a).

[0235] In embodiments, as described in European Patent Application No. 08101442.5 or U.S. Patent Application Publication No. 2013 / 240388A1 or WO2009 / 152031, the second and / or third compartments may be manufactured in a separate step and then combined with the first compartment.

[0236] In an embodiment, the pouch may be made according to a process comprising: a) optionally, using heat and / or vacuum and using a first non-woven web or laminate, forming a first compartment with a first forming machine; b) filling the first compartment with a first composition; c) optionally, filling a second compartment with a second composition; d) sealing the first and optionally the second compartments to the first non-woven web or laminate with a second non-woven web or laminate; and e) cutting the non-woven web or laminate to produce a multi-compartment pouch.

[0237] In an embodiment, the pouch may be made according to a process comprising: a) optionally, using heat and / or vacuum and using a first non-woven web or laminate, forming a first compartment with a first forming machine; b) filling the first compartment with a first composition; c) using a second forming machine, optionally using heat and vacuum, to deform a second non-woven web or laminate to create a second and optionally a third formed compartment; d) filling the second and optionally the third compartments; e) sealing the second and optionally the third compartments with a third non-woven web or laminate; f) placing the sealed second and optionally the third compartments on top of the first compartment; g) sealing the first, second and optionally the third compartments; and h) cutting the non-woven web or laminate to produce a multi-compartment pouch.

[0238] The first and second forming machines may be selected based on their suitability for performing the above process. In an embodiment, the first forming machine is preferably a horizontal forming machine and the second forming machine is preferably located above the first forming machine and is preferably a rotary drum forming machine.

[0239] It should be understood that, with the use of appropriate supply stations, it may be possible to manufacture multi-compartment pouches incorporating several different or distinct compositions and / or different or distinct liquid, gel, or paste compositions.

[0240] In the embodiment, the nonwoven web or laminate and / or pouch is sprayed or powdered with a suitable material, such as an activator, lubricant, aversive agent or a mixture thereof. In the embodiment, the nonwoven web or laminate and / or pouch is printed with, for example, ink and / or activator.

[0241] Vertical forming, filling, and sealing

[0242] In embodiments, the nonwoven web or laminate of the present disclosure may be formed into a sealed article. In embodiments, the sealed article is a vertically formed, filled and sealed article. The vertically formed, filled and sealed (VFFS) method is a conventional automated process. VFFS includes equipment such as an assembly machine that winds a single piece of nonwoven web or laminate around a vertically oriented feed tube. The machine heat-seals or otherwise secures the opposing ends of the nonwoven web or laminate together to create a side seal and form a hollow tube of nonwoven web or laminate. The machine then heat-seals or otherwise creates a bottom seal, thereby defining a container portion having an open top from which a top seal is later formed. The machine introduces a specific amount of fluid product into the container portion through the open top end. Once the container contains the desired amount of product, the machine feeds the nonwoven web or laminate to another heat-sealing device, for example, to create a top seal. Finally, the machine feeds the nonwoven web or laminate to a cutter that cuts the film just above the top seal to provide the filled package.

[0243] During operation, the assembly machine feeds the nonwoven web or laminate from the roll to form the package. Therefore, the nonwoven web or laminate must be able to pass through the machine easily, must not adhere to the machine assembly, and must not be so brittle as to break during processing.

[0244] Contents of the pouch

[0245] In any embodiment, the pouch may contain (encapsulate) the composition within a defined internal volume of the pouch. The composition may be selected from liquid, solid, or a combination thereof. In embodiments where the composition is liquid, the nonwoven web may be a non-porous or porous nonwoven web laminated with a water-soluble film, the water-soluble film forming the inner surface of the pouch. In embodiments where the composition is solid, the pouch may include a non-porous nonwoven web, a porous nonwoven web laminated with a water-soluble film, or a porous nonwoven web. In embodiments where the pouch includes a porous nonwoven web, the particle size of the solid composition is smaller than the pore size of the nonwoven web.

[0246] In embodiments, the sealed articles of the present disclosure may contain compositions in the internal pouch volume that include liquid laundry detergent, agricultural compositions, automatic dishwasher compositions, household cleaning compositions, water treatment compositions, personal care compositions, food and nutritional compositions, industrial cleaning compositions, medical compositions, antibacterial compositions, pet compositions, office compositions, livestock compositions, industrial compositions, aquaculture compositions, commercial compositions, military compositions, recreational compositions, or combinations thereof. In embodiments, the water-dispersible sealed articles of the present disclosure may contain compositions in the internal pouch volume that include liquid laundry detergent, agricultural compositions, automatic dishwasher compositions, household cleaning compositions, water treatment compositions, personal care compositions, or combinations thereof. In embodiments, the water-dispersible sealed articles of the present disclosure may contain compositions in the internal pouch volume that include liquid laundry detergent, agricultural compositions, automatic dishwasher compositions, household cleaning compositions, water treatment compositions, personal care compositions, or combinations thereof. In embodiments, the water-dispersible sealed articles of the present disclosure may contain a composition comprising an agricultural composition or a water treatment composition within the internal pouch volume.

[0247] As used herein, “liquid” includes free-flowing liquids, as well as pastes, gels, foams, and mousses. Non-limiting examples of liquids include lightweight and heavy liquid detergent compositions, dishwashing detergents for hand and / or machine washing; hard surface cleaning compositions, fabric strengtheners, detergent gels commonly used for laundry, bleaches and laundry additives, shaving creams, skincare and haircare compositions (shampoos and conditioners), and body washes. Such detergent compositions may include surfactants, bleaches, enzymes, perfumes, dyes or colorants, solvents, and combinations thereof. If necessary, detergent compositions are selected from the group consisting of laundry detergents, dishwashing detergents, hard surface cleaning compositions, fabric strengthener compositions, shaving creams, skincare and haircare compositions (shampoos and conditioners), and body washes, and combinations thereof.

[0248] Non-limiting examples of liquids include agricultural compositions, automotive compositions, aircraft compositions, food and nutritional compositions, industrial compositions, livestock compositions, aquaculture compositions, medical compositions, commercial compositions, military and paramilitary compositions, office compositions, recreation and park compositions, pet compositions, and water treatment compositions, and cleaning and detergent compositions applicable to any such use.

[0249] Gases, such as suspended bubbles, or solids, such as particles, may be contained within the liquid. As used herein, “solid” includes, but is not limited to, powders, aggregates, and mixtures thereof. Non-limited examples of solids include granules, microcapsules, beads, noodles, and pearl balls. Solid compositions may offer technical benefits, including, but are not limited to, the benefit of being washable, pretreatment benefits, and / or aesthetic effects.

[0250] The composition may be a non-household care composition. For example, a non-household care composition may be selected from agricultural compositions, aircraft compositions, food and nutritional compositions, industrial compositions, livestock compositions, aquaculture compositions, medical compositions, commercial compositions, military and paramilitary compositions, office compositions, recreation and park compositions, pet compositions, and water treatment compositions, and includes cleaning and detergent compositions applicable to any such use, but excluding cloth and household care compositions.

[0251] In one embodiment, the composition may contain pesticides, such as one or more insecticides, fungicides, herbicides, insecticides, acaricides, repellents, attractants, defoliants, plant growth regulators, fertilizers, fungicides, micronutrients, and trace elements. Suitable pesticides and secondary agents are described in U.S. Patents 6,204,223 and 4,681,228, and EP0989803A1. For example, suitable herbicides include paraquat salts (e.g., paraquat dichloride or paraquat bis(methyl sulfate)), diquat salts (e.g., diquat dibromide or diquat alginate), and glyphosate or its salts or esters (e.g., glyphosate isopropylammonium, glyphosate sesquisodium, or glyphosate trimesium, also known as sulfosate). Unsuitable pairs of crop protection chemicals can be used in a separate chamber, as described, for example, in U.S. Patent No. 5,558,228. Suitable unsuitable pairs of crop protection chemicals include, for example, bensulfuron-methyl and molinate; 2,4-D and thifensulfuron-methyl; 2,4-D and methyl 2-[[[[N-4-methoxy-6-methyl-1,3,5-triazine-2-yl)-N-methylamino]carbonyl This includes amino]-sulfonyl]benzoate; 2,4-D and metosulfuron-methyl; maneb or mancozeb and benomyl; glyphosate and metosulfuron-methyl; tralomethrin and any organophosphate, e.g., monoclotophos or dimethoate; bromoxynyl and N-[[4,6-dimethoxypyrimidine-2-yl)-amino]carbonyl]-3-(ethylsulfonyl)-2-pyridine-sulfonamide; bromoxynyl and methyl 2-[[[[(4-methyl-6-methoxy)-1,3,5-triazine-2-yl)amino]carbonyl]amino]sulfonyl]benzoate; and bromoxynyl and methyl 2-[[[[N-(4-methoxy-6-methyl-1,3,5-triazine-2-yl)-N-methylamino]carbonyl]amino]sulfonyl]benzoate.In another related type of embodiment, the composition may include one or more species, together with soil as needed, and further optionally, one or more additional components selected from mulch, sand, peat moss, water jelly crystals, and fertilizers, including, for example, embodiments of the type described in U.S. Patent No. 8,333,033.

[0252] In another type of embodiment, the composition is a water treatment agent. Such agents may contain strong chemicals, such as active oxidizing chemicals, as described, for example, in U.S. Patent Application Publication No. 2014 / 0110301 and U.S. Patent No. 8,728,593. For example, disinfectants may contain hypochlorites, such as sodium hypochlorite, calcium hypochlorite, and lithium hypochlorite; chlorinated isocyanurates, such as dichloroisocyanuric acid (also known as "dichloro" or dichloro-s-triazinetrione, 1,3-dichloro-1,3,5-triazinan-2,4,6-trione) and trichloroisocyanuric acid (also known as "trichloro" or 1,3,5-trichloro-1,3,5-triazinan-2,4,6-trione). Salts and hydrates of disinfectant compounds are also intended. For example, dichloroisocyanuric acid may be provided in the form of sodium dichloroisocyanurate, sodium dichloroisocyanurate dihydrate, and so on. Bromine-containing disinfectants, including, for example, 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), 2,2-dibromo-3-nitrilopropionamide (DBNPA), dibromocyanoacetate amide, 1-bromo-3-chloro-5,5-dimethylhydantoin; and 2-bromo-2-nitro-1,3-propanediol may also be suitable for use in unit-dose packaging applications. The oxidizing agent may be one of those described in U.S. Patent No. 7,476,325, for example, potassium peroxybisulfate. The composition may be a pH-adjusting chemical as described in, for example, U.S. Patent Application Publication No. 2008 / 0185347, and may contain acidic and alkaline components such that the composition is effervescent when in contact with water and adjusts the pH of the water. Suitable components include sodium bicarbonate, sodium bisulfate, potassium hydroxide, sulfamic acid, organic carboxylic acids, sulfonic acids, and potassium dihydrogen phosphate. Buffering blends may include, for example, boric acid, sodium carbonate, glycolic acid, and oxone persulfate.

[0253] The water treatment agent may be or may contain a flocculant, for example, as described in U.S. Patent Application Publication No. 2014 / 0124454. The flocculant may include polymer flocculants, such as polyacrylamide, polyacrylamide copolymers, such as acrylamide copolymer of diallydimethylammonium chloride (DADMAC), dimethylaminoethyl acrylate (DMAEA), dimethylaminoethyl methacrylate (DMAEM), 3-methylamidopropyltrimethylammonium chloride (MAPTAC), or acrylic acid; cationic polyacrylamide; anionic polyacrylamide; neutral polyacrylamide; polyamine; polyvinylamine; polyethyleneimine; polydimethyldiallylammonium chloride; polyoxyethylene; polyvinyl alcohol; polyvinylpyrrolidone; polyacrylic acid; polyphosphate; polystyrene sulfonic acid; or any combination thereof. The flocculant may be selected from chitosan acetate, chitosan lactate, chitosan adipate, chitosan glutamate, chitosan succinate, chitosan malate, chitosan citrate, chitosan fumarate, chitosan hydrochloride, and combinations thereof. The water treatment composition may contain one or more phosphate removal substances selected from, for example, zirconium compounds, rare earth lanthanide salts, aluminum compounds, iron compounds, or combinations thereof.

[0254] The composition may be, for example, a limescale removal composition as described in U.S. Patent Application No. 2006 / 0172910, such as citric acid or maleic acid, or their sulfates, or any mixture thereof.

[0255] Various other types of compositions, including fine particles, e.g., feathers, as described in US RE29059 E; superabsorbent polymers, e.g., as described in U.S. Patent Application Publications 2004 / 0144682 and 2006 / 0173430; pigments and tinters, e.g., as described in U.S. Patent No. 3,580,390 and U.S. Patent Application Publications 2011 / 0054111; brazing fluxes, e.g., alkali metal fluoroaluminates, alkali metal fluorosilicates and alkali metal fluorozincates, as described in U.S. Patent No. 8,163,104; foodstuffs, e.g., coffee powder or dried soup, as described in U.S. Patent Application Publication 2007 / 0003719; and wound dressings, e.g., as described in U.S. Patent No. 4,466,431, are intended for use in the packets described herein.

[0256] In a pouch containing a laundry, laundry additive, and / or fabric strengthening composition, the composition may contain one or more of the following non-limiting list of components: fabric care beneficial agents; cleaning enzymes; deposit aids; rheology modifiers; builders; bleaching agents; bleaching precursors; bleaching enhancers; bleaching catalysts; perfumes and / or perfume microcapsules (see, for example, U.S. Patent No. 5,137,646); perfume-filled zeolites; starch-encapsulated accords. accord); polyglycerin esters; whitening agents; pearlescent agents; enzyme stabilization systems; scavengers including fixatives for anionic pigments, complexing agents for anionic surfactants and mixtures thereof; fluorescent whitening agents or fluorescent agents; polymers including, but not limited to, soil-release polymers and / or soil-suspending polymers; dispersants; defoaming agents; non-aqueous solvents; fatty acids; foam inhibitors, e.g., silicone foam inhibitors (see U.S. Patent Application Publication No. 2003 / 0060390A1, paragraphs 65-77); cationic starch (U.S. Patent Application Publication No. See U.S. Patent Publication No. 2004 / 0204337A1 and U.S. Patent Publication No. 2007 / 0219111A1; scum dispersants (see U.S. Patent Publication No. 2003 / 0126282A1, paragraphs 89-90); direct dyes; coloring dyes (see U.S. Patent Publication No. 2014 / 0162929A1); colorants; opacifiers; antioxidants; hydrotropes, e.g., toluenesulfonate, cumenesulfonate, and naphthalenesulfonate; colored specks; colored beads, spheres, or extruders; clay softeners; antibacterial agents. Any one or more of these components are further described in U.S. Patent Publication No. 2010 / 305020A1, U.S. Patent Publication No. 2003 / 0139312A1, and U.S. Patent Publication No. 2011 / 0023240A1. In addition, or alternatively, the composition may include a surfactant, a quaternary ammonium compound, and / or a solvent system. The quaternary ammonium compound may be present in the fabric strengthening agent composition, for example, in the fabric softener, and has structure NR4. + The formula contains a quaternary ammonium cation, which is a positively charged polyatomic ion of (wherein R is an alkyl group or an aryl group).

[0257] composite article

[0258] The composite articles of the present disclosure include at least two layers of nonwoven webs. The composite articles of the present disclosure may have a first layer of a first nonwoven web containing a first plurality of fibers having a first diameter, a second layer of a second nonwoven web containing a second plurality of fibers having a second diameter, and a first interface containing at least a portion of the first nonwoven web and at least a portion of the second nonwoven web, to which the portion of the first nonwoven web and the portion of the second nonwoven web are fused, wherein the second diameter is smaller than the first diameter. Any nonwoven layer of the composite article may include a water-soluble film laminated thereto.

[0259] The composite articles of this disclosure may offer one or more advantages compared to a single-layer composite article alone or the same nonwoven web, including, but are not limited to, increased mechanical strength, improved liquid-receiving capabilities compared to a single-layer composite article alone or the same nonwoven web (e.g., liquid-receiving layer of a diaper or spill-absorbing wipe), and / or improved liquid retention and / or active composition (e.g., active lotion of a wet wipe) compared to a single-layer composite article alone or the same nonwoven web.

[0260] The first interface, which includes at least a portion of the first nonwoven web and at least a portion of the second nonwoven web, is a region of composite where the first and second nonwoven webs overlap and multiple fibers of the first and second nonwoven webs are mixed. Generally, the portion of the first nonwoven web forming the first interface is the outer surface of the first nonwoven web. In embodiments, the first interface constitutes 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 10% or less, 5% or less, 2.5% or less, or 1% or less of the thickness of the first nonwoven web. In embodiments, the first interface constitutes at least 0.1%, at least 0.5%, at least 1%, or at least 5% of the thickness of the first nonwoven web. In embodiments, the first interface constitutes about 0.1% to about 25% of the thickness of the first nonwoven web. Generally, the portion of the second nonwoven web forming the interface is the outer surface of the second nonwoven web. In embodiments, the interface constitutes 75% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, or 15% or less of the thickness of the second nonwoven web. In embodiments, the first interface constitutes at least 1%, at least 5%, at least 10%, at least 20%, at least 25%, at least 30%, or at least 40% of the thickness of the second nonwoven web. In embodiments, the first interface constitutes about 1% to about 75% of the thickness of the second nonwoven web.

[0261] As used herein, unless otherwise specified, two nonwoven webs are “fused” if at least a portion of the fibers from each web are bonded to the fibers from the other web. As described herein, fiber bonding includes fiber entanglement. Two nonwoven webs may be fused using any preferred method. In embodiments, portions of the first nonwoven web and portions of the second nonwoven web are thermally fused, solvent-fused, or both. In embodiments, portions of the first nonwoven web and portions of the second nonwoven web are thermally fused. Thermal fusion may include the use of heat and / or pressure. In embodiments, one or both of the two separate nonwoven webs may be heated until the fibers soften, and then the webs are compressed together, and as the fibers cool, at least a portion of the fibers from each web are bonded to at least a portion of the fibers from the other web. In embodiments, one or both of the first and second nonwoven webs may be applied in an in-line process such that melt-spun and heated soft fibers are applied directly to the pre-formed nonwoven web after passing through a die assembly and fuse to the fibers of the pre-formed nonwoven to form a fusion interface. In embodiments, portions of the first nonwoven web and portions of the second nonwoven web are solvent-fused. Solvent fusion may involve applying a binder solution to one or both of the nonwoven webs and subsequently bringing the nonwoven webs into contact such that, upon drying, at least a portion of the fibers from each web fuses to at least a portion of the fibers from the other web. Solvent fusion may be carried out as a separate process involving two separate pre-formed webs, or it may be an in-line process in which the binder solution is applied to the pre-formed nonwoven web and the second nonwoven web is formed on the pre-formed nonwoven web in a continuous process. The binder solution for solvent fusion of the nonwoven webs may be any binder solution described herein for bonding. As used herein, unless otherwise specified, “pre-formed nonwoven web” includes nonwoven webs that are formed but not bonded, and nonwoven webs that are formed and bonded.As used herein, unless otherwise specified, “separate nonwoven webs” encompass nonwoven webs formed by carding or airlaiding staple fibers or by a continuous process, and the nonwoven webs may be bonded or unbonded. In embodiments, fusion of two nonwoven webs can also be used to bond one or both nonwoven webs.

[0262] In the embodiment, the first interface is solvent-fused, and the solvent is selected from the group consisting of water, ethanol, methanol, DMSO, glycerin, and combinations thereof. In the embodiment, the first interface is solvent-fused, and the solvent is selected from the group consisting of water, glycerin, and combinations thereof. In the embodiment, the first interface is solvent-fused using a binder solution containing polyvinyl alcohol and water, glycerin, or a combination thereof. In the embodiment, the first interface is solvent-fused using a binder solution containing polyvinyl alcohol, latex, or a combination thereof and water, glycerin, or a combination thereof.

[0263] As used herein, unless otherwise specified, if the average fiber diameter of a first type of fiber is smaller than the average fiber diameter of a second type of fiber, then the first type of fiber has a diameter "smaller" than the diameter of the second type of fiber. For example, the first type of fiber may have a diameter size distribution that overlaps with that of the second type of fiber, and still have a smaller diameter as long as the average fiber diameter for the first type of fiber is smaller than the average fiber diameter for the second type of fiber. In embodiments, the smaller fiber type has an average fiber diameter smaller than the minimum diameter of the diameter size distribution of the larger fiber type. A difference in diameter exists if the difference can be visualized using projection microscopy imaging, as outlined in SO137:2015. In embodiments, for example, if multiple meltspun layers are used, the difference in diameter between the smaller and larger fiber types may be submicron. In embodiments, the difference in diameter between smaller and larger fiber types may be approximately 1 micron to 300 microns, approximately 5 microns to 300 microns, approximately 5 microns to 250 microns, approximately 5 microns to 200 microns, approximately 10 microns to 150 microns, approximately 10 microns to 100 microns, approximately 10 microns to 90 microns, approximately 15 microns to 80 microns, approximately 15 microns to 70 microns, approximately 20 microns to 60 microns, approximately 20 microns to 50 microns, or approximately 25 microns to 45 microns. In embodiments, the difference in diameter between smaller and larger fiber types may be approximately 5 microns to 75 microns. In embodiments, the difference in diameter between smaller and larger fiber types may be approximately 20 microns to 80 microns. Without intending to be bound by theory, by fusing nonwoven webs and providing a composite of two nonwoven webs in which the second nonwoven web has a smaller fiber diameter than the first nonwoven web, it is advantageous that the adsorption / absorption rate and fluid capacity of the composite article may be improved, direct adsorption / absorption from larger diameter fibers to smaller diameter fibers where the fluid preferentially moves may be improved; the surface-to-volume ratio of the nonwoven composite article may be increased compared to a single-diameter material, and as a result, it is thought that the filling capacity may be increased and / or dispersion may be improved and / or the total dissolution of the nonwoven composite article may be improved compared to a nonwoven with a single-diameter material.The average diameter of the fibers in each web layer may be any diameter presented herein. In embodiments, the first plurality of fibers in the first layer of the first nonwoven fabric may have a diameter of about 10 microns to about 300 microns, about 50 microns to about 300 microns, or more than about 100 microns to about 300 microns. In embodiments, the first plurality of fibers may have an average diameter of more than about 100 microns to about 300 microns. In embodiments in which the nonwoven layers of a nonwoven composite material include a blend of fiber types having different diameters, the average fiber diameter refers to the average fiber diameter of the blend when the fiber diameter distribution is unimodal. The blend of fiber types may have a bimodal or higher-order fiber diameter distribution of the nonwoven layers. If the fiber blend has a bimodal or higher-order peaked diameter distribution, the fiber has a smaller diameter than the fibers of the blend if the average fiber diameter is smaller than the average of the minimum diameter fiber distribution of the blend, and the fiber has a larger diameter than the fibers of the blend if the average fiber diameter is larger than the average of the larger diameter fiber distribution of the blend.

[0264] In some embodiments, the composite article further includes a third layer of a third nonwoven web containing a third plurality of fibers. In embodiments in which the nonwoven composite article includes a third layer of a third nonwoven web, a second layer may be provided between the first and third layers, and at least a second portion of the second nonwoven web and at least a portion of the third nonwoven web may fuse to form a second interface. The second interface, which includes at least a second portion of the second nonwoven web and at least a portion of the third nonwoven web, is a region of the composite where the second and third nonwoven webs overlap and the second plurality of fibers and the third plurality of fibers are mixed. In some embodiments, depending on the thickness of the second layer of the second nonwoven web, the first plurality of fibers and the third plurality of fibers may be mixed and / or fused such that there is no clear demarcation between the first interface and the second interface. Generally, the portion of the second nonwoven web forming the second interface is the outer surface of the second nonwoven web opposite to the outer surface of the second nonwoven web fused to the first nonwoven web. In embodiments, the second interface constitutes 75% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, or 15% or less of the thickness of the second nonwoven web. In embodiments, the second interface constitutes at least 1%, at least 5%, at least 10%, at least 20%, at least 25%, at least 30%, or at least 40% of the thickness of the second nonwoven web. In embodiments, the second interface constitutes about 1% to about 75% of the thickness of the second nonwoven web. In embodiments, the portion of the third nonwoven web forming the second interface is the outer surface of the third nonwoven web. In the embodiment, the second interface comprises 50% or less of the thickness of the third nonwoven web, 40% or less, 30% or less, 25% or less, 20% or less, 10% or less, 5% or less, 2.5% or less, or 1% or less of the thickness of the first nonwoven web. In the embodiment, the second interface comprises at least 0.1%, at least 0.5%, at least 1%, or at least 5% of the thickness of the third nonwoven fabric.In the embodiment, the second interface constitutes approximately 0.1% to approximately 25% of the thickness of the third nonwoven fabric.

[0265] In the embodiment, the second portion of the second nonwoven web and the portion of the third nonwoven web are thermally fused, solvent-fused, or both. In the embodiment, the second portion of the second nonwoven web and the portion of the third nonwoven web are thermally fused. In the embodiment, the second portion of the second nonwoven web and the portion of the third nonwoven web are solvent-fused.

[0266] In the embodiment, the second interface is solvent-fused, and the solvent is selected from the group consisting of water, ethanol, methanol, DMSO, glycerin, and combinations thereof. In the embodiment, the second interface is solvent-fused, and the solvent is selected from the group consisting of water, glycerin, and combinations thereof. In the embodiment, the second interface is solvent-fused using a binder solution containing polyvinyl alcohol and water, glycerin, or a combination thereof. In the embodiment, the second interface is solvent-fused using a binder solution containing polyvinyl alcohol, latex, or a combination thereof and water, glycerin, or a combination thereof.

[0267] In embodiments, the first layer of the first nonwoven web and the second layer of the second nonwoven web have different porosities. As used herein, unless otherwise specified, two nonwoven webs have "different porosities" if the difference in porosity between the nonwoven webs is at least about 1%. In embodiments, the difference in porosity between two layers of a nonwoven web in a composite article can be about 1% to about 20%. For example, one layer of the nonwoven web in a composite article may have a porosity of about 80%, and the second layer of the nonwoven web in a composite article may have a porosity of about 85%, with a difference in porosity of 5%. In embodiments, the porosity of the second nonwoven web is lower than that of the first nonwoven web. In embodiments, the porosity of the second nonwoven web is the same as that of the first nonwoven web. As used herein, unless otherwise specified, two nonwoven webs have "the same porosity" if the difference in porosity value between them is less than 1%.

[0268] In embodiments where the composite article includes a third layer of a third nonwoven web, the third nonwoven web may have the same or different porosity as the first nonwoven web. In embodiments, the third nonwoven web may have the same porosity as the first nonwoven web. In embodiments, the third nonwoven web may have a different porosity than the first nonwoven web. In embodiments, the third nonwoven web may have a lower porosity than the first nonwoven web. In embodiments, the third nonwoven web may have the same porosity as the second nonwoven web. In embodiments, the third nonwoven web may have a different porosity than the second nonwoven web. In embodiments, the third nonwoven web may have a lower porosity than the second nonwoven web. In embodiments, the second nonwoven web may have a lower porosity than the first nonwoven web, and the third nonwoven web may have a lower porosity than the second nonwoven web. In embodiments, the nonwoven composite article may have a porosity gradient between the layers of the nonwoven web, with one outer surface of the composite structure having maximum porosity and the other outer surface of the composite structure having minimum porosity. In embodiments, the composite structure may have a porosity gradient between the layers of the nonwoven web, with the outer surface of the composite structure having maximum porosity and the intermediate layer(s) of the composite structure having minimum porosity. In embodiments, the composite structure may include a fourth or more layers of the nonwoven web, with the intermediate layer(s) including the second and third layers of the nonwoven web (in the case of a four-layer composite structure), or the third layer of the nonwoven web (in the case of a five-layer composite structure).

[0269] Without intending to be bound by theory, if the porosity of a composite material structure includes a gradient, the composite material structure is likely to have enhanced liquid absorption from the more porous outer surface to the less porous outer surface or the less porous intermediate layer(s).

[0270] Multiple fibers in any given nonwoven fabric layer of a composite article may be any of the fibers disclosed herein, and may be the same or different. In embodiments, the composition of the fiber-forming material of the first, second, and third multiple fibers may be the same or different, for example, in terms of diameter, length, toughness, shape, stiffness, elasticity, solubility, melting point, glass transition temperature (T g ), have any differences in fiber-forming material, color or combination thereof. Table 1 below shows a composite article intended to include fibers having three different fiber compositions in the nonwoven layer, where the letters "A", "B", and "C" refer to a specific fiber composition, and "-" means that the intended composite article does not include a third layer of the nonwoven web. Each of fiber compositions A, B, and C may be (a) a single fiber type containing a single fiber-forming material, (b) a single fiber type containing a blend of fiber-forming materials, (c) a blend of fiber types in which each fiber type contains a single fiber-forming material, (d) a blend of fiber types in which each fiber type contains a blend of fiber-forming materials, or (e) a blend of fiber types in which each fiber type contains a single fiber-forming material or a blend of fiber-forming materials. [Table 1]

[0271] In embodiments, the first plurality of fibers comprises a water-soluble polyvinyl alcohol (PVOH) fiber-forming material. As described herein, the term “PVOH fiber” is understood to include homopolymers, copolymers, or modified copolymers containing a vinyl alcohol moiety, such as fibers containing 50% or more of a vinyl alcohol moiety, and fibers containing polymers that have been chemically modified with a modifier. Chemically modified fibers may not contain a vinyl alcohol moiety, or may contain less than 50% of a vinyl alcohol moiety. In embodiments, the second plurality of fibers comprises a water-soluble polyvinyl alcohol fiber-forming material. In embodiments, the first plurality of fibers and the second plurality of fibers comprise a water-soluble polyvinyl alcohol fiber-forming material. In embodiments comprising a third layer of a nonwoven web having a third plurality of fibers, the third plurality of fibers may comprise a water-soluble polyvinyl alcohol fiber-forming material. In embodiments, the polyvinyl alcohol fiber-forming material may be present in one or more fiber types of the plurality of fibers. The water-soluble polyvinyl alcohol fiber-forming material for any of the first, second, or third plurality of fibers may be any water-soluble polyvinyl alcohol fiber-forming material disclosed herein. In embodiments in which two or more of the first plurality of fibers, second plurality of fibers and / or third plurality of fibers are polyvinyl alcohol fiber-forming material, the polyvinyl alcohol may be the same or different in each plurality, and in each plurality may be a single fiber-forming material or part of a blend of fiber-forming materials, and if each plurality contains different polyvinyl alcohol fibers, the length-to-diameter ratio (L / D), toughness, shape, stiffness, elasticity, solubility, melting point, glass transition temperature (T) may be described. g ), there may be differences in fiber chemistry, color, or combinations thereof.

[0272] In the embodiment, the fibers of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers may include fiber-forming materials other than polyvinyl alcohol fiber-forming materials.

[0273] In the embodiments, the first nonwoven web has a toughness ratio (MD:CD) of about 0.5 to about 1.5. In the embodiments, the first nonwoven web has an MD:CD of about 0.8 to about 1.25. In the embodiments, the first nonwoven web has an MD:CD of about 0.9 to about 1.1. In the embodiments, the second nonwoven web has a toughness ratio (MD:CD) of about 0.5 to about 1.5. In the embodiments, the second nonwoven web has an MD:CD of about 0.8 to about 1.25. In the embodiments, the second nonwoven web has an MD:CD of about 0.9 to about 1.1. In the embodiments, the third nonwoven web has a toughness ratio (MD:CD) of about 0.5 to about 1.5. In the embodiments, the third nonwoven web has an MD:CD of about 0.8 to about 1.25. In the embodiment, the third nonwoven web has an MD:CD ratio of about 0.9 to about 1.1. In the embodiment, the nonwoven composite article has a toughness ratio (MD:CD) in the range of about 0.5 to about 1.5, about 0.8 to about 1.25, about 0.9 to about 1.1, or about 0.95 to about 1.05. In the embodiment, the nonwoven composite article has an MD:CD ratio of about 0.8 to about 1.5. In the embodiment, the nonwoven composite article has an MD:CD ratio of about 0.9 to 1.1. The MD:CD of the nonwoven composite article is related to the MD:CD ratio of each individual layer of the nonwoven web present in the composite article. Without intending to be bound by theory, the MD:CD of the composite article cannot be determined by individually considering the MD and CD of each layer of the nonwoven web, but it is considered that the MD and CD of the nonwoven composite article must be measured. Without intending to be bound by theory, it is assumed that as the toughness ratio MD:CD of a nonwoven composite article approaches 1, the durability of the composite article increases, and it is given superior resistance to the decomposition of the nonwoven when stress is applied to the nonwoven during use. Furthermore, without intending to be bound by theory, it is assumed that the MD:CD ratio of a composite article containing at least one meltspun nonwoven web will be closer to 1:1 than that of an identical composite article, except that it contains all carding layers.

[0274] The basis weight of the nonwoven composite articles disclosed herein is not particularly limited and is approximately 5 g / m². 2 ~Approx. 150g / m 2 , about 5g / m2 ~Approx. 125g / m 2 , about 5g / m 2 ~about 100g / m 2 , about 5g / m 2 ~about 70g / m 2 , about 5g / m 2 ~about 50g / m 2 , about 5g / m 2 ~About 30g / m 2 It may be within the range of. In embodiments, the nonwoven composite article of the present disclosure is approximately 5 g / m². 2 ~about 50g / m 2 It may have a basis weight of approximately 50 g / m². In embodiments, the nonwoven composite article of the present disclosure has a basis weight of approximately 50 g / m². 2 ~Approx. 150g / m 2 It may have a basis weight of approximately 30 g / m². In this embodiment, the first layer of the nonwoven web has a basis weight of approximately 30 g / m². 2 ~about 70g / m 2 The basis weight may be approximately 60 g / m² for nonwoven composite articles. 2 ~Approx. 150g / m 2 It may have a basis weight of approximately 5 g / m². In this embodiment, the first layer of the nonwoven web has a basis weight of approximately 5 g / m². 2 ~about 15g / m 2 It may have a basis weight of approximately 5 g / m². In this embodiment, the first layer of the nonwoven web has a basis weight of approximately 5 g / m². 2 ~about 15g / m 2 The basis weight may be approximately 15 g / m² for nonwoven composite articles. 2 ~about 50g / m 2 It may have a basis weight in the range of [value]. In the embodiment, the third layer of the nonwoven web is about 5 g / m². 2 ~about 15g / m 2 It may have a basis weight of approximately 5 g / m². In this embodiment, the first layer of the nonwoven web has a basis weight of approximately 5 g / m². 2 ~about 15g / m 2 The third layer of the nonwoven web may have a basis weight of approximately 5 g / m². 2 ~about 15g / m 2It may have a basis weight of . In an embodiment, the second layer of the nonwoven web may be included in the composite article at a concentration of about 2.5 wt.% to about 10 wt.% based on the total weight of the composite article. In an embodiment, the second layer of the nonwoven web may be included in the composite article at a concentration of about 2.5 wt.% to about 10 wt.% based on the total weight of the composite article, and the first layer of the nonwoven web may be included in the composite article at a concentration of about 90 wt.% to about 97.5 wt.% based on the total weight of the composite article. In an embodiment, the second layer of the nonwoven web may be included in the composite article at a concentration of about 2.5 wt.% to about 10 wt.% based on the total weight of the composite article, and the first layer of the nonwoven web and the third layer of the nonwoven web together are included at a concentration of about 90 wt.% to about 97.5 wt.% based on the total weight of the composite article. In the embodiment, the third layer of nonwoven web may be included in the composite article in an amount of about 2.5 wt.% to about 10 wt.% based on the total weight of the composite article, and the first layer of nonwoven web and the second layer of nonwoven web together may be included in an amount of about 45 wt.% to about 48 wt.% based on the total weight of the composite article.

[0275] In the embodiment, the fiber diameters of the first plurality of fibers may be substantially uniform. In the embodiment, the fiber diameters of the second plurality of fibers may be substantially uniform. In the embodiment, the fiber diameters of the third plurality of fibers may be substantially uniform. In the embodiment, the fiber diameters of the first plurality of fibers and the third plurality of fibers may be substantially uniform. In the embodiment, the fiber diameters of each of the first plurality of fibers, the second plurality of fibers and the third plurality of fibers may be substantially uniform.

[0276] In the embodiment, the nonwoven composite article may have improved modulus, tensile strength, elongation, toughness, or a combination thereof in the machining direction, the intersecting direction, or both, compared to the same article containing only the first layer. In the embodiment, the nonwoven composite article may have improved modulus, tensile strength, elongation, toughness, or a combination thereof in the machining direction, compared to the same article containing only the first layer. In the embodiment, the nonwoven composite article may have improved modulus, tensile strength, elongation, toughness, or a combination thereof in the intersecting direction, compared to the same article containing only the first layer. In the embodiment, the nonwoven composite article may have improved modulus, tensile strength, elongation, toughness, or a combination thereof in the machining direction and the intersecting direction, compared to the same article containing only the first layer.

[0277] Method for preparing composite articles

[0278] The composite article can be manufactured using any process known in the art that is suitable for combining two or more layers of a nonwoven web such that at least a portion of the first layer and a portion of the second layer are fused together to form an interface.

[0279] In the embodiments, a method for forming a nonwoven composite article of the present disclosure is: (a) The step of depositing a second layer, which includes the second nonwoven web, on a first layer, which includes the first nonwoven web, under conditions sufficient to fuse at least a portion of the first nonwoven web with at least a portion of the second nonwoven web, thereby forming a first interface; and (b) The step of depositing a third layer, including the third nonwoven web, on a second layer, including the second nonwoven web, under conditions sufficient to fuse at least a second portion of the second nonwoven web with at least a portion of the third nonwoven web, thereby forming a second interface. It may include.

[0280] In embodiments, steps (a) and (b) may be repeated to include additional nonwoven layers, such as a fourth nonwoven layer, a fifth nonwoven layer, and so on, in the composite material structure.

[0281] Conditions sufficient to fuse at least a portion of the first nonwoven web with at least a portion of the second nonwoven web and / or fuse at least a second portion of the second nonwoven web with at least a portion of the third nonwoven web may include thermal fusion and / or solvent fusion as described herein.

[0282] In embodiments of the method described above, the first layer may include a carding nonwoven web. In embodiments of the method described above, the third layer may include a carding nonwoven web or a meltspun nonwoven web. In embodiments of the method described above, the second layer may include a meltspun nonwoven web or an airlaid nonwoven web. In embodiments, the first layer may include a carding nonwoven web, the second layer may include a meltspun nonwoven web, and the third layer may include a carding nonwoven web. In embodiments, the first layer may include a carding nonwoven web, the second layer may include a meltblown nonwoven web, and the third layer may include a carding nonwoven web. In embodiments, the second layer may include an airlaid nonwoven web. In embodiments, the first layer may include a carding nonwoven web, the second layer may include an airlaid nonwoven web, and the third layer may include a meltspun nonwoven web. In one embodiment, the first layer may include a carding nonwoven web, the second layer may include an airlaid nonwoven web, and the third layer may include a meltblown nonwoven web. In another embodiment, the nonwoven composite article may include five layers of nonwoven webs, the first layer may include a carding nonwoven web, the second layer may include an airlaid nonwoven web, the third layer may include a meltspun nonwoven web, the fourth layer may include an airlaid nonwoven web, and the fifth layer may include a carding nonwoven web. In yet another embodiment, the nonwoven composite article may include five layers of nonwoven webs, the first layer may include a carding nonwoven web, the second layer may include an airlaid nonwoven web, the third layer may include a meltblown nonwoven web, the fourth layer may include an airlaid nonwoven web, and the fifth layer may include a carding nonwoven web. In the embodiment, the second nonwoven web may include a cellulose fiber forming material.

[0283] Flushable wipes

[0284] The flushable wipes of this disclosure may include the nonwoven webs and / or composite articles of this disclosure.

[0285] A flushable wipe may comprise multiple fibers of the present disclosure, the multiple fibers may comprise water-soluble fibers and, optionally, water-insoluble fibers.

[0286] In embodiments in which a water-soluble wipe comprises a nonwoven web containing water-soluble fibers and water-insoluble fibers, the ratio of water-insoluble fibers to water-soluble fibers may be in the range of about 1:18 to about 4:1, about 1:10 to about 3:1, about 1:5 to about 2:1, or about 1:2 to about 2:1, for example, about 1:18, 1:16, 1:14, 1:12, 1:10, 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, or 4:1.

[0287] The flushable wipes of the present disclosure may include a cleaning lotion. The flushable wipes of the present disclosure generally include fibers having a surface energy high enough to allow the fibers to be easily wetted by the cleaning lotion during the wetting step of the wipe manufacturing process. Therefore, in embodiments, at least a portion of at least one outer layer of the nonwoven composite article of the flushable wipes includes hydrophilic fibers. In embodiments, at least a portion of each outer layer of the nonwoven composite article used to prepare the flushable wipes includes hydrophilic fibers. As used herein, unless otherwise specified, “hydrophilic fiber” means any fiber whose surface is hydrophilic. A fiber may have a hydrophilic surface if, for example, the fiber includes a hydrophilic fiber-forming material, the fiber is a core / sheath type two-component fiber with a hydrophilic fiber-forming material in the sheath, and / or the fiber is surface-treated to include a hydrophilic material on its surface. Without intending to be bound by theory, it is conceivable that hydrophilic fibers in nonwoven fabrics can promote capillary action / water absorption of liquids from the surface of the nonwoven fabric, providing improved liquid acquisition compared to the same nonwoven fabric without hydrophilic fibers.

[0288] Non-limiting uses of wipes include surface cleaning, skin cleaning, automotive applications, baby care, women's care, hair cleaning, and removal or application of cosmetics, skin conditioners, ointments, sunscreens, insect repellents, pharmaceuticals, varnishes, or industrial and machine cleaning.

[0289] Lotion composition

[0290] The water-soluble wipes of this disclosure may include a lotion composition that wets the substrate and promotes cleaning. In embodiments where the water-soluble wipes are personal care wipes, the lotion composition may also include ingredients for, for example, soothing, softening or caring for the skin, improving the feel of the lotion, improving the removal of residue from the skin, providing a pleasant fragrance, and / or preventing bacterial growth.

[0291] The lotion composition may have a pH of about 5.5 or close to physiological skin pH. Low pH lotion compositions may have a pH of about 3.8 or close to it and may be useful when the wipe is used to remove alkaline residues, e.g., residues from bowel waste, helping to restore a healthy acidic skin pH of about 5 and / or making irritants from bowel waste non-irritating by inactivating fecal enzymes. Low pH lotions may also inhibit microbial growth. In embodiments where the pH of the lotion composition is about 4 or less, the fibers of the first plurality of fibers, the second plurality of fibers and / or the third plurality of fibers may comprise polyvinyl alcohol copolymers. The copolymers may be provided as a single fiber-forming material in the fibers of a fiber blend, or as a component of the fiber-forming material in the fibers comprising a blend of fiber-forming materials. In improvements of the embodiments described above, the fibers may comprise a blend of polyvinyl alcohol copolymers and homopolymers. The polyvinyl alcohol copolymers and homopolymers may be provided in a ratio of about 1:1 to about 4:1. In further improvements to the embodiments described above, the polyvinyl alcohol copolymer-containing fibers may be blended with water-insoluble fibers. Either or both of the polyvinyl copolymer and homopolymer may be chemically modified with the modifiers described herein.

[0292] The lotion composition may contain a superwetter, a rheological modifier, a softener, and / or an emulsifier. The superwetter may be present in an amount of about 0.01% to 0.2% by weight relative to the total weight of the lotion composition. The superwetter may be selected from the group consisting of trisiloxane, polyether dimethicone (where the polyether functional group is PEG, PPG, or a mixture thereof), and mixtures thereof.

[0293] The rheological modifier may be present in a rheological amount of approximately 0.01% to 0.5% by weight based on the total weight of the lotion composition. The rheological modifier may be selected from the group consisting of xanthan gum, modified xanthan gum, and combinations thereof.

[0294] If present, the softening agent may be a viscosity softening agent. Suitable softening agents are not limited to these, but include PEG-10 sunflower oil glyceride, sunflower oil, palm oil, olive oil, emu oil, babassu oil, evening primrose oil, palm kernel oil, liver oil, cottonseed oil, jojoba oil, meadowfoam seed oil, sweet almond oil, canola oil, soybean oil, avocado oil, safflower oil, coconut oil, sesame oil, rice bran oil, grape seed oil, mineral oil, isopropyl stearate, isostearyl isononanoate, diethylhexyl fumarate, diiso This product contains stearyl malate, triisocetyl citrate, stearyl stearate, methyl palmitate, methylheptyl isostearate, petrolatum, lanolin oil and lanolin wax, cetyl alcohol, stearyl alcohol, behenyl alcohol, isostearyl alcohol and long-chain alcohols such as 2-hexyl-decanol, myristyl alcohol, dimethicone solution of various molecular weights and mixtures thereof, PPG-15 stearyl ether (also known as arlatone E), shea butter, olive butter, sunflower butter, coconut butter, jojoba butter, cocoa butter, squalane and squalene, isoparaffin, polyethylene glycol of various molecular weights, polypropylene glycol of various molecular weights or mixtures thereof.

[0295] The emulsifier, if present, may be solid at room temperature. Suitable emulsifiers are not limited to, but include, laureth-23, ceteth-2, ceteth-10, ceteth-20, ceteth-21, ceteareth-20, steareth-2, steareth-10, steareth-20, oleth-2, oleth-10, oleth-20, steareth-100, steareth-21, PEG-40 sorbitan peroleate, PEG-8 stearate, PEG-40 stearate, PEG-50 stearate, PEG-100 stearate, sorbitan laurate, sorbitan palmitate, sorbitan stearate, and sorbitan tristearate. This product contains sorbitan oleate, sorbitan trioleate, polysorbate 20, polysorbate 21, polysorbate 40, polysorbate 60, polysorbate 61, polysorbate 65, polysorbate 80, polysorbate 81, polysorbate 85, PEG-40 hydrogenated castor oil, citrate ester, microcrystalline wax, paraffin wax, beeswax, carnauba wax, ozokerite wax, cetyl alcohol, stearyl alcohol, cetearyl alcohol, myristyl alcohol, behenyl alcohol, and mixtures thereof.

[0296] In this embodiment, the cleansing lotion comprises an aqueous emulsion containing a softening agent and an emulsifier.

[0297] The cleansing lotion may further include, but is not limited to, hydrating agents including glycerin, propylene glycol, and phosphoripides; fragrances such as essential oils and perfumes as described herein; preservatives; enzymes; colorants; oil absorbents; insecticides; fertilizers; activators; acid catalysts; metal catalysts; ion scavengers; detergents; disinfectants; surfactants; bleaches; bleaching agents; and fabric softeners. In embodiments, the cleansing lotion includes fragrances, preservatives, enzymes, colorants, oil absorbents, insecticides, ion scavengers, detergents, disinfectants, or combinations thereof.

[0298] Preservatives prevent microbial growth in liquid lotions, water-soluble wipes, and / or substrates on which wipes are used. Preservatives may be hydrophobic or hydrophilic. Suitable preservatives include, but are not limited to, parabens such as methylparaben and propylparaben, alkyl glycinates, iodine derivatives, and combinations thereof.

[0299] The lotion filling amount may range from 150% to 480%. As used herein, “filling” means combining a nonwoven web or composite article with a lotion composition, regardless of the method used to combine the nonwoven web or composite article with the lotion composition, i.e., immersion, spray, kiss roll, etc., i.e., the lotion composition is filled on or inside the nonwoven web or composite article. “Lotion filling amount” means the amount of lotion filled on or inside the nonwoven web or composite article, expressed as a percentage of the weight of the lotion relative to the weight of the dry (unfilled) nonwoven web or composite article. Water-soluble wipes may be desirable to be filled with lotion to such an extent that some lotion can be easily transferred to the substrate (e.g., skin or another surface to be cleaned) during use. Transfer may allow for the transfer of compounds that promote cleansing, provide a pleasant sensation to the user (such as a smooth skin feel or a cooling sensation due to evaporation), and / or provide beneficial functions to the substrate.

[0300] Water-flushable wipes can be nonwoven webs or composite articles having high-density interstitial spaces between the fibers constituting the wipe. To maintain sufficient lotion available on the surface of the wipe for transfer to the substrate, a large portion of the interstitial spaces in the wipe may be filled with lotion. The lotion in the interstitial spaces does not need to be readily available for transfer to the substrate, for example, so that the wipe can be filled with an excess of lotion in sufficient quantity to inform the user that the lotion is available for transfer to the substrate by providing a sufficient feeling of wetness. Advantageously, nonwoven composite articles used for water-flushable wipes may have a porosity gradient as described herein, which can facilitate the filling of lotion into the wipe.

[0301] Flushable wipes can be made by wetting a nonwoven web or composite article with at least 1 gram of liquid cleansing lotion per gram of dry fibrous composite. Preferred methods for delivering the cleansing lotion to the nonwoven web or composite article include, but are not limited to, immersion, spraying, embedding, extrusion coating, and dip coating. After wetting, the wet composite article may be folded, laminated, cut to length, and wrapped as desired. Flushable wipes are generally small enough to be easily disposed of in a sewage system while being convenient to handle. The wet composite article may be cut or folded to such dimensions during the manufacturing process, or it may be larger in size and have means, such as perforations, that allow the user to separate individual wipes from the web to the desired size.

[0302] In embodiments, the flushable wipes of the Disclosure comprise the nonwoven web and cleaning lotion of the Disclosure. In embodiments, the flushable wipes of the Disclosure comprise the nonwoven composite article and cleaning lotion of the Disclosure. In embodiments, the flushable wipes of the Disclosure comprise the nonwoven composite article and cleaning lotion of the Disclosure.

[0303] Absorbent articles

[0304] The nonwoven webs and nonwoven composite articles of this disclosure can be used as liquid-receiving layers in absorbent articles. Absorbent articles may include bibs, chest pads, care mats, cleansing pads (e.g., floor cleansing pads), diapers, pull-up diapers, incontinence liners, pads and other articles (e.g., adult incontinence diapers, adult incontinence pads, adult incontinence pants, toilet training liners, toilet training pads, toilet training pants and pet training pads, e.g., puppy pads), interlabial devices, menstrual pads, panty liners, sanitary napkins, tampons, spill-absorbing mats, spill-absorbing pads, spill-absorbing rolls, wound dressings, and the like. In one embodiment, any of the aforementioned articles may be disposable. The term "disposable" means an article designed or intended to be discarded after a single use. That is, disposable articles are not intended to be washed or otherwise restored or reused, and in embodiments, they may not be washable, restored or reused.

[0305] As used herein, the term “absorbent article” includes articles that absorb and contain liquids such as bodily exudates. The term “absorbent article” is intended to include diapers, incontinence articles, sanitary napkins, etc. The term “incontinence article” is intended to include pads, underwear (pads held in place by some kind of support system such as a belt, etc.), absorbent article inserts, absorbent article volume boosters, briefs, bed pads, etc., whether worn by an adult or another person with incontinence. At least some such absorbent articles are intended to absorb bodily fluids such as menstrual blood or blood, vaginal secretions, urine, sweat, breast milk, and bowel excrement.

[0306] As used herein, “diaper” means a device placed against the wearer’s skin and intended to absorb and contain various exudates discharged from the body. Diapers are generally worn by infants and incontinenced individuals around the lower torso, encircling the wearer’s waist and legs. Examples of diapers include infant or adult diapers and pant-like diapers such as training pants. “Training pants” as used herein means disposable underwear with waist and leg openings designed for infant or adult wearers. Pants may be positioned on the wearer by inserting the wearer’s legs into the leg openings and moving the pants to a position around the lower torso of the wearer. Pants may be pre-formed by any preferred technique, including, but not limited to, re-fastening and / or non-re-fastening joints (e.g., seams, welds, adhesives, tight-fitting bonds, fasteners, etc.) that connect parts of the article together. Pants may be pre-formed at any position along the perimeter of the article (e.g., lateral fastening, front waist fastening).

[0307] In embodiments, the absorbent article of the present disclosure includes a liquid-permeable top sheet, a liquid-impermeable back sheet connected to the top sheet, and a liquid-receiving layer and an absorbent core between the top sheet and the back sheet. In embodiments where the absorbent article is a wearable article (e.g., an incontinence article, a sanitary napkin, etc.), the article may have a wearer side and an outer side. Generally, the liquid-permeable top sheet is on the wearer side of the absorbent article, and the liquid-impermeable back sheet is on the outer side. The absorbent core is generally a sheet-like structure and, when provided as a wearable item, has a wearer side and an outer side.

[0308] The liquid-permeable topsheet may be any liquid-permeable topsheet known in the art. In the case of wearable articles, the topsheet may be fully or partially stretchable, or shortened to have a void between the topsheet and the absorbent core. The liquid-impermeable backsheet may be any liquid-impermeable backsheet known in the art. The backsheet prevents the leachate absorbed by the absorbent core and contained within the article from coming into contact with any substrate that the absorbent article may come into contact with. The backsheet is liquid-impermeable and may include laminates of nonwoven fabrics and plastic thin films such as thermoplastic films. Preferred backsheet films include those manufactured by Tredegar Industries Inc. at Terre Haute, Ind. and sold under trade names X15306, X10962, and X10964. Other preferred backsheet materials may include permeable materials that allow vapor to escape from the absorbent article while preventing liquid from passing through the backsheet. Exemplary breathable materials may include materials such as woven webs and nonwoven webs, as well as composite materials such as those manufactured by Mitsui Toatsu Col in Japan under the designation ESPOIR NO. and those manufactured by EXXON Chemical Co. in Bay City, Tex. under the designation EXXAIRE.

[0309] The absorbent core is placed between the top sheet and the back sheet. The absorbent core may contain any absorbent material capable of absorbing and retaining liquids such as urine and other bodily exudates. The absorbent core may contain a wide variety of liquid absorbent materials commonly used in disposable diapers and other absorbent articles, such as superabsorbent polymers, crushed wood pulp (air felt), crepe-processed cellulose wadding; absorbent foam, absorbent sponge, absorbent gelling material, or any other known absorbent material, or combination of materials. The absorbent core may contain small amounts (less than about 10%) of non-liquid absorbent material, such as adhesives, waxes, oils, etc.

[0310] The liquid acquisition layer comprises a nonwoven web of the Disclosure comprising a plurality of fibers comprising a water-soluble polyvinyl alcohol fiber-forming material as described herein. The plurality of fibers may comprise a single fiber type or a blend of fiber types, and the fibers may comprise a single polyvinyl alcohol fiber-forming material or a blend of fiber-forming materials comprising a polyvinyl alcohol fiber-forming material. The fibers may comprise fibers chemically modified with modifiers as described herein.

[0311] In embodiments, the liquid-receiving layer may be provided between the absorbent core and the top sheet. In wearable embodiments, the liquid-receiving layer may be provided on the wearer side of the absorbent core. In embodiments, the liquid-receiving layer may be provided between the absorbent core and the back sheet. In wearable embodiments, the liquid-receiving layer may be provided on the outer surface of the absorbent core. In embodiments, the liquid-receiving layer wraps around the absorbent core. The liquid-receiving layer may be a single sheet wrapping around the absorbent core, or may be provided as two connected individual layers. Without intending to be bound by theory, it is considered advantageous that including a liquid-receiving layer between the absorbent core and the back sheet, or on the outer surface of the absorbent core, prevents liquid leakage from the absorbent article by providing additional liquid-receiving material that captures any spillage of liquid from the top sheet side and / or the wearer side.

[0312] The liquid acquisition layer may be in direct contact with the absorbent core, may include a space between the absorbent core and the liquid acquisition layer, or may include an intervening layer between the absorbent core and the liquid acquisition layer. In embodiments, the liquid acquisition layer is in contact with the absorbent core. In embodiments, the absorbent article includes an intervening layer provided between the acquisition layer and the absorbent core. In embodiments, the liquid acquisition layer is in contact with the absorbent core on the top sheet side / wearer side, and the intervening layer is provided between the acquisition layer and the absorbent core on the back sheet side / outer side. In embodiments, the liquid acquisition layer is in contact with the absorbent core on the back sheet side / outer side, and the intervening layer is provided between the acquisition layer and the absorbent core on the top sheet side / wearer side. The intervening layer may be, for example, a second liquid-permeable layer or liquid acquisition layer included to help and facilitate the spread of liquid from the point of deposition to cover the entire area of ​​the absorbent core.

[0313] In embodiments, the absorbent article includes a liquid-receiving layer which is a nonwoven web of the Disclosure. In embodiments, the wearable absorbent article includes a liquid-receiving layer which is a nonwoven web of the Disclosure. In embodiments, the absorbent article includes a liquid-receiving layer which is a nonwoven composite article of the Disclosure. In embodiments, the wearable absorbent article includes a liquid-receiving layer which is a nonwoven composite article of the Disclosure. Dissolution and disintegration test (MSTM-205)

[0314] Nonwoven webs, water-soluble films, or laminate structures can be characterized or tested by dissolution time and disintegration time according to MonoSol Test Method 205 (MSTM 205), a method known in the art. See, for example, U.S. Patent No. 7,022,656. The descriptions provided below refer to nonwoven webs, but are equally applicable to water-soluble films or laminate structures. The equipment and materials include: 600 mL beaker, Magnetic stirrer (Labline model number 1250 or equivalent), Magnetic stirring rod (5cm), Thermometer (0~100℃±1℃), Casting mold, stainless steel (3.8cm x 3.2cm), Timer (0-300 seconds, accuracy in seconds), Polaroid 35mm slide mount (or equivalent), MonoSol 35mm slide mount holder (or equivalent), and Distilled water.

[0315] For each nonwoven web to be tested, three test specimens measuring 3.8 cm × 3.2 cm are cut from the nonwoven web sample. The specimens should be cut evenly spaced along the transverse direction of the web from the web area. Each test specimen is then analyzed using the following procedure.

[0316] Each specimen is mounted on a separate 35mm slide mount.

[0317] Fill a beaker with 500 mL of distilled water. Measure the water temperature with a thermometer and, if necessary, heat or cool the water to maintain a temperature that determines the solubility, for example, 20°C (approximately 68°F).

[0318] Mark the water column height. Place the magnetic stirrer on the holder base. Place the beaker on top of the magnetic stirrer, insert the magnetic stirring rod into the beaker, activate the stirrer, and adjust the stirring speed until a vortex is created that reaches approximately one-fifth the height of the water column. Mark the depth of the vortex.

[0319] Secure the 35mm slide mount to the alligator clip clamp of the 35mm slide mount holder so that the long end of the slide mount is parallel to the water surface. The holder depth should be adjusted so that when dropped, the end of the clamp is 0.6 cm below the water surface. One short end of the slide mount should be placed against the side of the beaker and the other end directly relative to the center of the stirring rod so that the nonwoven web surface is perpendicular to the flow of water.

[0320] In a single operation, the fixed slide and clamp are dropped into the water, and the timer is activated. Fracture occurs when the sample is damaged within the slide, for example, when a hole is made. Disintegration occurs when the nonwoven web separates and no sample material remains on the slide. Once all visible nonwoven webs have detached from the slide mount, the slide is removed from the water, while monitoring the solution for undissolved nonwoven web fragments continues. Dissolution occurs when all nonwoven web fragments are no longer visible and the solution becomes clear. For nonwoven samples prepared from polyvinyl alcohol with a low degree of hydrolysis (e.g., about 65-88%), fracture and dissolution may occur simultaneously. If there is a difference of 5 seconds or longer between fracture and dissolution, the dissolution time should be recorded independently of the fracture time.

[0321] The thinning time can also be determined using MSTM-205. Thinning of a nonwoven web occurs when some of the fibers that make up the web dissolve, while other fibers remain intact. Web thinning occurs before the web collapses. Thinning is characterized by a decrease in the opacity of the nonwoven web or an increase in its transparency. The change from opacity to gradually increasing transparency can be observed visually. During MSTM-205, monitor the opacity / transparency of the nonwoven web after the fixed slide and clamp have fallen into the water. Record the time when no further change in opacity / transparency is observed (i.e., the web is no longer opaque or transparent) as the thinning time.

[0322] The results should include the following: complete identification of the sample, individual and mean decay and dissolution times, and the water temperature at which the sample was tested. Method for determining the solubility of a single fiber

[0323] The solubility of a single fiber can be characterized by its water splitting temperature. The fiber splitting temperature can be determined as follows: A load of 2 mg / dtex is applied to a fiber with a fixed length of 100 mm. The water temperature is started at 1.5°C and then increased by 1.5°C every 2 minutes until the fiber splits. The temperature at which the fiber splits is recorded as the water splitting temperature.

[0324] The solubility of a single fiber can also be characterized by its temperature of complete dissolution. The temperature of complete dissolution can be determined as follows: Add 0.2 g of fiber with a fixed length of 2 mm to 100 mL of water. Start with a water temperature of 1.5 °C and then increase it by 1.5 °C every 2 minutes until the fiber is completely dissolved. Stir the sample at each temperature. The temperature at which the fiber completely dissolves in less than 30 seconds is recorded as the temperature of complete dissolution. Diameter Test Method

[0325] The diameter of individual fibers or fibers within a nonwoven web is determined using a scanning electron microscope (SEM) or optical microscope and image analysis software. A magnification of 200–10,000x is selected so that the fibers are adequately magnified for measurement. When using an SEM, the sample is sputtered with a gold or palladium compound to avoid charging and vibration of the fibers in the electron beam. A manual procedure for determining fiber diameter is used from images (on a monitor screen) taken with the SEM or optical microscope. Using mouse and cursor tools, locate the end of a randomly selected fiber and then measure across its width to the other end of the fiber (i.e., perpendicular to the fiber direction at that point). A scaled and calibrated image analysis tool provides actual readings in microns. For fibers within a nonwoven web, several fibers are randomly selected across a sample of the nonwoven web using an SEM or optical microscope. At least two sections of the nonwoven web material are cut and tested in this manner. Perform such measurements at least 100 times in total, and then record all the data for statistical analysis. Use the recorded data to calculate the mean (geometric mean) of the fibers, the standard deviation of the fibers, and the median of the fiber diameters. Tensile strength, elastic modulus, and elongation tests

[0326] Nonwoven webs, water-soluble films, or laminate structures characterized or tested by tensile strength according to tensile strength (TS) tests, modulus of elasticity (or tensile stress) according to modulus of elasticity (MOD) tests, and elongation according to elongation tests are analyzed as follows. The descriptions provided below refer to nonwoven webs, but are equally applicable to water-soluble films or laminate structures. The procedure includes determining the tensile strength and modulus of elasticity at 10% elongation according to ASTM D 882 ("Standard Test Methods for Tensile Properties of Thin Plastic Sheets") or its equivalent. An INSTRON tensile testing apparatus (Model 5544 tensile testing machine or equivalent) is used to collect nonwoven web data. A minimum of three test specimens, each cut with a reliable cutting tool to ensure dimensional stability and repeatability, are tested in the machining direction (MD) (where applicable) for each measurement. Tests are performed in a standard laboratory atmosphere of 23±2.0°C and 35±5% relative humidity. To determine the tensile strength or modulus of elasticity, a 1-inch wide (2.54 cm) sample of the nonwoven web is prepared. The sample is then transferred to an INSTRON tensile testing machine and tested, while minimizing exposure to a 35% relative humidity environment. The tensile testing machine is prepared according to the manufacturer's instructions, equipped with a 500N load cell, and calibrated. The correct grips and faces are installed (INSTRON grips with rubber-coated 25 mm wide faces, model number 2702-032, or equivalent). The sample is fitted into the tensile testing machine and analyzed to determine the 100% modulus of elasticity (i.e., the stress required to achieve 100% film elongation), tensile strength (i.e., the stress required to break the film), and elongation % (sample length at break compared to initial sample length). Generally, a higher elongation % of the sample indicates better processability characteristics of the nonwoven web (e.g., increased formability into packets or pouches). Determination of basis weight

[0327] The basis weight is determined according to ASTM D3776 / D3776M-09a (2017). In short, at least 130 cm². 2 A nonwoven fabric specimen having an area of ​​at least 130 cm², or taken from different locations on the sample. 2Cut several smaller die-cut specimens with a total area of ​​. Weigh the specimen(s) on a top-loading chemical scale with a resolution of ±0.001 g to determine their mass. Protect the scale from airflow and other disturbances using a fume shield. Cloth specimens may be weighed together. Calculate the mass to three significant figures in ounces per square yard, ounces per linear yard, or grams per pound per linear yard or square meter. Determination of water vapor transmission rate

[0328] The water vapor transmission rate (MVTR) is determined according to MSTM-136. MVTR defines how much moisture moves through the sample per day. The description provided below refers to nonwoven webs, but is equally applicable to water-soluble films or laminate structures.

[0329] The equipment and materials include: Permatran-W Model 3 / 34 (or equivalent), High-pressure nitrogen gas cylinder (99.7% or higher), Regulator Tee (part number 027-343), Main line supply regulator, HPLC-grade water (or equivalent), 10cc syringe with Luerlok tip (part number 800-020) Powder-free gloves, High vacuum grease (part number 930-022), (2) Test cell, Cutting mold, Cutting board, Laser blade with handle, and Cut-resistant gloves.

[0330] Preparation of Permatran W-Model 3 / 34: Ensure the nitrogen pressure level is above 300 psi, the carrier gas regulator tee pressure reading is 29 psi (not exceeding 32 psi), and the main line supply regulator pressure is set to 35 psi. Open the instrument panel door and use the humidifier to check the water level. If the water level is low, fill a syringe with HPLC-grade water and insert the luer attached to the syringe into the reservoir's "fill port". Open the "fill valve" by turning it counterclockwise 2-3 times, then push the plunger into the syringe to fill the reservoir with water. Close the "fill valve" and remove the syringe. The water level should not exceed the line marked adjacent to the reservoir.

[0331] Sample Preparation and Testing: For each nonwoven web to be tested, take a sample web and place it flat on a cutting board. Place a mold on top of the web and cut out the samp...

Claims

1. A method for processing fibers, comprising contacting the surface of a fiber containing a polymer comprising at least one vinyl acetate portion or a vinyl alcohol portion with a modifying agent to chemically modify at least a portion of the polymer with the modifying agent in a region of the fiber including at least the surface of the fiber, thereby forming a modified fiber. Includes, Here, the monomer units of the modifying agent are incorporated into the polymer in an amount of 1.0 mol% to 10 mol%, and the monomer units are not crosslinked in the modified fiber. Here, the modified fiber is water-soluble, Here, bringing the surface of the fiber into contact with the modifying agent includes mixing the fiber, which contains at least one of a vinyl acetate portion or a vinyl alcohol portion, the modifying agent, and the solvent. Here, the surface of the fiber is brought into contact with the modifying agent at a temperature in the range of 10°C to 100°C for a period of up to 48 hours. Here, the modifying agent includes anhydrides, carboxylic acids, alcohols, esters, ethers, sulfonic acids, sulfonates, click chemistry reagents, amides, amines, lactams, nitriles, ketones, allyl-containing compounds, acetyl-containing compounds, halogens, alkyl-containing compounds, imides, acetal-containing compounds, enolates, nitro-containing compounds, silanes, aziridines, isocyanates, or any combination thereof. The method wherein the solvent comprises one or more solvents selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, tetrahydrofuran, dichloromethane, acetone, N-methylpyrrolidone, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, formic acid, water, and any combination thereof.

2. The method according to claim 1, wherein the fibers are insoluble in the solvent for the duration of the fiber's contact with the solvent.

3. The method according to claim 1, further comprising heating the fibers in the solvent before bringing the surface of the fibers into contact with the modifying agent.

4. The method according to claim 1, wherein the polymer comprising at least one vinyl acetate portion or vinyl alcohol portion has a degree of hydrolysis higher than 79% and less than 99.9% before the surface of the fiber is brought into contact with the modifying agent.

5. The method according to claim 1, wherein the chemical modification of at least a portion of the polymer by the modifying agent includes one or more of the following: esterification, amidation, amination, carboxylation, nitration, acyloin condensation, allylation, acetylation, imidation, halogenation, sulfonation, alkylation, enolation, nitrosation, and silane coupling.

6. The method according to claim 1, further comprising mixing an activator with the fiber and the modifying agent, wherein the activator comprises an acid, a base, an aziridine, a free radical initiator, or a combination thereof.

7. The method according to claim 1, wherein the modified fiber comprises a monocarboxylic acid, a dicarboxylic acid, a sulfonic acid, a sulfonate, a click chemistry reagent, an amide, an amine, a nitrile, a ketone, an ester, an allyl, an acetyl, a halogen, an alkyl, an imide, an acetal, an enolate, a nitro, a silane, or any combination thereof.

8. The method according to claim 1, wherein the sulfonate comprises aminopropyl sulfonate.

9. The method according to claim 1, wherein the lactam comprises pyrrolidone or caprolactam.

10. The method according to claim 1, wherein the sulfonic acid comprises 2-acrylamido-2-methylpropanesulfonic acid.

11. The method according to claim 7, wherein the monocarboxylic acid or the dicarboxylic acid includes acetic acid, maleic acid, maleic acid monoalkyl, maleic acid dialkyl, fumaric acid, fumaric acid monoalkyl, fumaric acid dialkyl, itaconic acid, itaconic acid monoalkyl, itaconic acid dialkyl, citraconic acid monoalkyl, citraconic acid dialkyl, mesaconic acid monoalkyl, mesaconic acid dialkyl, glutaconic acid monoalkyl, glutaconic acid dialkyl, alkyl (alkyl) acrylates, alkali metal salts thereof, hydrolyzed alkali metal salts thereof, esters thereof, or any combination thereof.

12. The method according to claim 1, wherein the modifying agent comprises an anhydrous substance.

13. The method according to claim 12, wherein the anhydride is an organic acid anhydride, and the organic acid anhydride includes acetic acid anhydride, propionic acid anhydride, isobutyric acid anhydride, maleic acid anhydride, phthalic acid anhydride, glutaric acid anhydride, itaconic acid anhydride, citraconic acid anhydride, glutaconic acid anhydride, or any combination thereof.

14. The method according to claim 12, wherein the anhydride includes maleic anhydride.

15. The method according to claim 1, wherein the denaturing agent is provided in an amount of 0.2% to 75% (w / w) based on the weight of the solvent.

16. The method according to claim 1, wherein the solvent includes an alcohol that is a liquid under mixed conditions.

17. The method according to claim 1, wherein the solvent comprises a mixture of a first solvent and a second solvent.

18. The method according to claim 17, wherein the first solvent contains water and the second solvent contains an alcohol.

19. The method according to claim 18, wherein the second solvent comprises methanol, ethanol, n-propanol, isopropanol, or any combination thereof.

20. The method according to claim 1, wherein the surface of the fiber is brought into contact with the modifying agent under conditions sufficient to provide an anionically modified polymer.

21. The method according to claim 20, wherein the anionically modified polymer comprises a carboxylate, a sulfonate, or a combination thereof.

22. The method according to claim 1, wherein the polymer comprising at least one vinyl acetate portion or vinyl alcohol portion comprises a polyvinyl alcohol homopolymer, a polyvinyl acetate homopolymer, a polyvinyl alcohol copolymer, or a combination thereof.

23. The method according to claim 22, wherein the polyvinyl alcohol copolymer is a copolymer of vinyl acetate and vinyl alcohol.

24. The method according to claim 1, wherein the fiber further comprises an additional polymer.

25. The method according to claim 24, wherein the additional polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polyacrylate, water-soluble acrylate copolymer, polyvinylpyrrolidone, polyethyleneimine, pullulan, guar gum, acacia gum, xanthan gum, carrageenan, starch, modified starch, polyalkylene oxide, polyacrylamide, polyacrylic acid, cellulose, cellulose ether, cellulose ester, celluloseamide, polycarboxylic acid, polyamino acid, polyamide, gelatin, dextrin, copolymers of the aforementioned, and any combination of any of the aforementioned additional polymers or copolymers.

26. The method according to claim 1, wherein the surface of the fiber is brought into contact with the modifying agent under conditions sufficient to provide a fiber having a cross-section having a core-sheath structure including a core and a sheath, wherein the polymer of the core has a first amount of chemical modification, and the polymer of the sheath has a second amount of chemical modification greater than the first amount.

27. The method according to claim 1, wherein the surface of the fiber is brought into contact with the modifying agent under conditions sufficient to provide a fiber having a cross-section characterized by an increasing gradient of the amount of chemical modification of the polymer from the interior region to the surface region.

28. The method according to claim 1, wherein the surface of the fiber is brought into contact with the modifying agent under conditions sufficient to provide a fiber having a cross-section characterized by the polymer having an equal amount of chemical modification throughout the cross-section.

29. The method according to claim 1, wherein the fiber is water-soluble or not water-soluble before the surface of the fiber comes into contact with the modifying agent.

30. The method according to claim 1, wherein, before the surface of the fiber is brought into contact with the modifying agent, the fiber has a first complete dissolution temperature, and the modified fiber has a second complete dissolution temperature different from the first complete dissolution temperature.

31. The method according to claim 30, wherein the first complete dissolution temperature is higher than the second complete dissolution temperature.

32. The method according to claim 30, wherein the first complete dissolution temperature is lower than the second complete dissolution temperature.

33. The method according to claim 1, wherein contact of the surface of the fiber with the modifying agent is carried out by: dipping, spraying, transfer coating, water absorption, foaming, brushing, roll coating, humidification, vapor deposition, printing, or any combination thereof, one or more of these.

34. The method according to claim 33, wherein contacting the surface of the fiber with the modifying agent and solvent is performed after the formation of the fiber as part of a continuous in-line process.

35. The method according to claim 1, wherein the fiber is moving during the contact between the surface of the fiber and the modifying agent and solvent.

36. The method according to claim 1, wherein the contact of the surface of the fiber with the modifying agent is carried out in a batch process.

37. The method according to claim 1, wherein the fibers include staple fibers, staple yarn, fiber fill, needle-punched cloth, binding fibers, or any combination thereof.

38. The method according to claim 1, further comprising bringing the surface of the fiber into contact with the modifying agent, and then washing and drying the fiber.

39. The method according to claim 38, wherein washing the fibers includes rinsing the fibers with a non-solvent.

40. The method according to claim 38, wherein drying the fibers comprises one or more of the following: air jet drying, stirring, vortexing, centrifugal separation, or any combination thereof.

41. The method according to claim 1, wherein the fiber comprises a copolymer of vinyl alcohol and vinyl acetate having a degree of hydrolysis of 88%, 92%, or 96%, the modifying agent comprises maleic anhydride, the solvent comprises methanol, and the method further comprises mixing an activator comprising sodium hydroxide with the fiber, the modifying agent, and the solvent.

42. The fiber comprises a copolymer of vinyl alcohol and vinyl acetate having a degree of hydrolysis of 88%, 92%, or 96%, the modifying agent comprises maleic anhydride, the solvent comprises methanol, and the surface of the polymer-containing fiber is brought into contact with the modifying agent. The fiber and the solvent are combined to form a mixture. The mixture is heated to 55°C to 75°C to form a heated mixture. The heated mixture is to be mixed with the maleic anhydride and an activator containing sodium hydroxide to form a reaction mixture, and The reaction mixture is stirred at 55°C to 75°C for 3 to 7 hours. The method according to claim 1, including the method described in claim 1.

Images