Sulfonopolyesters containing 1,4-cyclohexanediethanol

Abstract

A water-dispersible sulfonyl polyester is provided, wherein the sulfonyl polyester comprises: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages. Woven and nonwoven articles are also provided.

Description

Technical Field

[0001] This invention relates to sulfonyl polyesters comprising 1,4-cyclohexanediethanol, methods for preparing the sulfonyl polyesters, fibers and fiber articles comprising the sulfonyl polyesters, and methods for preparing such fibers and fiber articles. The invention also relates to multicomponent fibers comprising sulfonyl polyesters and microdenier fibers, and fiber articles prepared therefrom. Background Technology

[0002] Sulfonated polyesters (SFPs) are water-dispersible due to the introduction of ionic groups within the polymer backbone, as described in numerous patents beginning around 1970. While sulfonated monomers provide the primary source of hydrophilicity, polyethylene glycols having the following formula are a key aspect of the prior art: H-(OCH2CH2) n -OH, where "n" is an integer from 2 to 4, to provide a secondary hydrophilic mechanism. The most commonly used polyethylene glycols are diethylene glycol (DEG) and triethylene glycol (TEG), with DEG being preferred. Both DEG and TEG tend to lower the glass transition temperature, which is detrimental to the production of multicomponent fibers that do not adhere to the spool during storage under high temperature and high humidity conditions. Reducing the polyethylene glycol content to increase the T... g This tends to reduce water dispersibility and make SFP removal difficult. For polyesters with low levels of diethylene glycol or triethylene glycol, increasing the sulfonyl monomer content increases melt viscosity, which limits the ability to obtain high molecular weights in melt-phase methods. A T... g => A water-dispersible polyester with a temperature range of 58°C, which is individually dispersed in water at a temperature of less than or equal to 90°C to form a dispersion of at least 5 wt%. The dispersion need not be clear or have low turbidity.

[0003] Fibers, meltblown fabrics, and other melt-spun fiber products are made from thermoplastic polymers such as poly(propylene), polyamide, and polyester. A common application of these fibers and fiber products is in nonwoven fabrics, particularly in personal care products such as wipes, feminine hygiene products, baby diapers, adult incontinence underwear, hospital / surgical and other medical disposable items, protective fabrics and layers, geotextiles, industrial wipes, and filter media. Unfortunately, personal care products made from conventional thermoplastic polymers are difficult to dispose of and often end up in landfills. A promising alternative is to make these products or their components "flushable," i.e., compatible with public drainage systems. The use of water-dispersible or water-soluble materials has also improved the recyclability and regeneration of personal care products. Currently, the various thermoplastic polymers used in personal care products are not inherently water-dispersible or soluble; therefore, products that are easily decomposed and can be disposed of in drainage systems or easily recycled have not been produced.

[0004] The desire for flushable personal care products has led to a need for fiber, nonwoven, and other fibrous articles with varying water responsiveness. Various approaches to addressing these needs have been described, for example, in the following documents: U.S. Patent Nos. 6,548,592; 6,552,162; 5,281,306; 5,292,581; 5,935,880; and 5,509,913; U.S. Patent Application Serial Nos. 09 / 775,312; and 09 / 752,017; and PCT International Publication No. WO 01 / 66666A2. However, these approaches have numerous drawbacks and do not provide a fibrous article, such as a fiber or nonwoven fabric, that achieves a satisfactory balance of various performance properties, such as tensile strength, absorbency, flexibility, and fabric integrity, under wet or dry conditions.

[0005] For example, typical nonwoven techniques are based on multidirectional fiber deposition, which is treated with resin-bonded binders to form a web with strong integrity and other desirable properties. However, the resulting fiber assemblies often have poor water responsiveness and are unsuitable for flushable applications. The presence of binders can also lead to undesirable properties in the final product, such as reduced sheet wettability, increased stiffness, tackiness, and higher production costs. It is also difficult to produce an binder that will exhibit sufficient wet strength during use and then rapidly disperse upon disposal. Therefore, nonwoven fiber assemblies using these binders may slowly degrade under ambient conditions or have insufficient wet strength in the presence of bodily fluids. To address this problem, pH and ion-sensitive water-dispersible binders, such as lattices containing acrylic or methacrylic acid, with or without salt, are known and described, for example, in U.S. Patent 6,548,592B1. In public and residential wastewater treatment systems, however, ion concentrations and pH levels can vary considerably across different geographical locations and may not be sufficient for the binder to become soluble and dispersible. In this case, the fiber products will not decompose after disposal and may clog drainage or sewer branches.

[0006] Multicomponent fibers containing both aqueously dispersible components and thermoplastic non-aqueously dispersible components have been described, for example, in the following U.S. Patent Nos.: 5,916,678; 5,405,698; 4,966,808; 5,525,282; 5,366,804; 5,486,418. For example, these multicomponent fibers can be bicomponent fibers with shaped or processed cross-sections, such as island-type, core-sheath-type, side-by-side, or segmented pie configurations. The multicomponent fibers can be subjected to water or dilute alkaline solutions, in which the aqueously dispersible components are dissolved, leaving the non-aqueously dispersible components as separate, individual fibers with extremely fine texture. However, polymers with good water dispersibility often impart adhesiveness to the resulting multicomponent fibers, causing them to stick together or fuse during winding or storage after several days, especially under hot and humid conditions. To prevent fusion, fatty acid or oil-based finishes are often applied to the surface of the fibers. Additionally, large proportions of pigments or fillers are sometimes added to water-dispersible polymers to prevent fiber fusion, as described in U.S. Patent 6,171,685. These oil-based finishing agents, pigments, and fillers require additional processing steps and may impart undesirable properties to the final fibers. Many water-dispersible polymers also require alkaline solutions for their removal, which can cause decomposition of other polymeric components of the fiber, such as reduced specific logarithmic viscosity, toughness, and melt strength. Furthermore, some water-dispersible polymers cannot withstand exposure to water during hydraulic entanglement and are therefore unsuitable for manufacturing nonwoven webs and fabrics.

[0007] Alternatively, water-dispersible components can be used as binders for the thermoplastic fibers in nonwoven webs. When exposed to water, the fiber-to-fiber bond breaks down, causing the nonwoven web to lose its integrity and decompose into individual fibers. These thermoplastic fiber components of the nonwoven web, however, are not water-dispersible and remain present in the aqueous medium, and therefore must ultimately be removed from municipal wastewater treatment plants. Hydraulic entanglement can be used to produce separable nonwoven fabrics, with or without very low levels (<5% by weight) of additional binders to hold the fibers together. While these fabrics may decompose upon disposal, they often utilize non-water-soluble or water-dispersible fibers and can cause entanglement and blockage in sewage systems. Any additional water-dispersible binders must also be minimally affected by hydraulic entanglement and not form gel-like deposits or crosslinks, thereby aiding in fabric treatment or addressing sewer-related problems.

[0008] Some water-soluble or water-dispersible polymers are available, but are generally not suitable for meltblown or melt-spinning operations. Polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylic acid are not melt-processable because thermal decomposition occurs below the point where a suitable melt viscosity is obtained. High molecular weight polyethylene oxide can have suitable thermal stability, but will provide a high-viscosity solution at the polymer interface, resulting in a slow decomposition rate. Water-dispersible sulfonyl polyesters have been described, for example, in the following U.S. patent numbers: 6,171,685; 5,543,488; 5,853,701; 4,304,901; 6,211,309; 5,570,605; 6,428,900; and 3,779,993. Typical sulfonyl polyesters, however, are low molecular weight thermoplastics that are brittle and lack flexibility, properties that make it difficult to withstand winding operations to obtain a roll of material without breakage or shredding. During processing into films or fibers, sulfonated polyesters can also exhibit adhesion or fusion, which may require the use of oil-based finishing agents or large amounts of pigments or fillers to avoid. Low molecular weight polyethylene oxide (more commonly known as polyethylene glycol) is a weak / brittle polymer that does not yet possess the physical properties required for fiber applications. Forming fibers from known water-soluble polymers via solution technology is an alternative, but the added complexity of removing the solvent (especially water) increases production costs.

[0009] Therefore, there is a need for water-dispersible sulfonated polyester fibers and fibrous articles prepared therefrom, which exhibit sufficient tensile strength, absorbency, flexibility, and fabric integrity in the presence of moisture, particularly when exposed to human bodily fluids. Additionally, there is a need for fibrous articles that do not require adhesives and are completely dispersed or soluble in residential or municipal drainage systems. Potential applications include, but are not limited to, meltblown webs, spunbond fabrics, hydraulically entangled fabrics, wet-laid nonwovens, dry-laid nonwovens, bicomponent fiber components, adhesion-promoting layers, cellulose plastic adhesives, washable nonwovens and films, soluble bonded fibers, protective layers, and carriers for active ingredients to be released or dissolved in water. There is also a need for multicomponent fibers with water-dispersible components that do not exhibit excessive filament adhesion or fusion during spinning operations, are easily desorbed by hot water at neutral or weakly acidic pH, are suitable for hydraulic entanglement processes to manufacture nonwovens, and are also used to produce yarns, woven fabrics, and various other fibrous articles. These multicomponent fibers can be used to prepare microfibers, which can be used to prepare a variety of articles. Other extrudable and melt-spun fiber materials are also possible. Summary of the Invention

[0010] We have unexpectedly discovered a sulfonated polyester with a glass transition temperature that allows it to be spun into fibers while also preventing the fibers from fusing together. Furthermore, this sulfonated polyester exhibits optimal water dispersibility compared to other sulfonated polyesters.

[0011] In one embodiment of the invention, a water-dispersible sulfonyl polyester is provided, comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all of the molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages.

[0012] In another embodiment of the invention, a water-dispersible sulfonyl polyester is provided, comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all of the molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages.

[0013] In another embodiment of the invention, a water-dispersible sulfonyl polyester is provided, comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent.

[0014] The sulfonyl polyester of the present invention can be used to produce single-component or multi-component fibers that are rapidly dispersed or soluble in water and can be produced by meltblowing or melt spinning. The fibers can be prepared from a single sulfonyl polyester or a blend of sulfonyl polyester with a water-dispersible or non-water-dispersible polymer. Therefore, the fibers of the present invention may optionally include a water-dispersible polymer blended with a sulfonyl polyester. Alternatively, the fibers may optionally include a non-water-dispersible polymer blended with a sulfonyl polyester, provided that the blend is immiscible. The present invention also includes fiber articles comprising our water-dispersible sulfonyl polyester fibers. Therefore, the fibers of the present invention can be used to prepare various fiber articles, such as yarns, meltblown webs, spunbond webs, and nonwoven fabrics, which are further water-dispersible or washable.

[0015] The present invention also provides a multicomponent fiber comprising a water-dispersible sulfonyl polyester and one or more non-water-dispersible polymers. The fiber has a processing geometry such that the non-water-dispersible polymers exist as segments substantially isolated from each other by intercalated sulfonyl polyesters, which act as an adhesive or encapsulating matrix for the non-water-dispersible segments.

[0016] Therefore, in one embodiment of the invention, a multicomponent fiber having a shaped cross section is provided, the multicomponent fiber comprising: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) residues of at least 10 molar percentages of at least one sulfonyl monomer, and (iii) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0017] In another embodiment of the invention, a multicomponent fiber having a shaped cross section is provided, the multicomponent fiber comprising: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) residues of at least 10 molar percentages of at least one sulfonyl monomer, (iii) residues of two or more diols, (iii) residues of 1,4-cyclohexanediethanol, and (iv) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0018] In another embodiment of the invention, a multicomponent fiber having a shaped cross section is provided, comprising: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of isophthalic acid, (ii) residues of terephthalic acid, (iii) residues of at least one sulfonyl monomer, (iv) residues of 1,4-cyclohexanediethanol; and (v) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0019] In another embodiment of the invention, a method for producing at least one multicomponent fiber having a shaped cross section is provided, comprising spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into a multicomponent fiber, the sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages.

[0020] In another embodiment of the invention, a method for producing at least one multicomponent fiber having a shaped cross section is provided, comprising spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into a multicomponent fiber, the sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages.

[0021] In another embodiment of the invention, a method for producing multicomponent fibers is provided. The method includes spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into multicomponent fibers, the sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 mol percent) and hydroxyl repetitive units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 mol percent.

[0022] Water-dispersible sulfonyl polyesters can be removed by contacting multicomponent fibers with water, leaving non-water-dispersible segments as microdenier fibers. Therefore, the present invention also provides a method for producing microdenier fibers, comprising: (A) spinning a water-dispersible sulfonyl polyester and one or more non-water-dispersible polymers immiscible with the sulfonyl polyester into multicomponent fibers, wherein the sulfonyl polyester is selected from at least one of: (1) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glassy appearance at at least 57°C. The chemical transformation temperature, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (2) a water-dispersible sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits at least 57 The glass transition temperature is ℃, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; and (3) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diglycerides. An alcohol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acid moiety repeating units (100 mol percent) and hydroxyl moiety repeating units (100 mol percent), and wherein all said moiety percentages are based on the sum of all acid and hydroxyl moiety repeating units equaling 200 mol percent; wherein the fiber has a plurality of segments comprising a non-aqueous dispersible polymer, wherein the segments are substantially isolated from each other by sulfonyl polyester interposed between said segments; and (B) contacting the multicomponent fiber with water to remove the sulfonyl polyester, thereby forming microdenier fibers.

[0023] The present invention also provides a method for preparing a water-dispersible, nonwoven fabric, comprising: (A) heating a water-dispersible polymer composition to a temperature above its flow point, wherein the polymer composition comprises at least one water-dispersible sulfonyl polyester selected from: (1) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition of at least 57°C. A temperature, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; (2) a water-dispersible sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glassy temperature of at least 57°C. The chemical transition temperature, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; and (3) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) at least 10 mol percent residues of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol. The sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 mol percent) and hydroxyl repetitive units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repetitive units equaling 200 mol percent; wherein the fiber has a plurality of segments comprising a non-aqueous dispersible polymer, wherein the segments are substantially isolated from each other by sulfonyl polyester interposed between the segments; and (B) melt spinning filaments; and (C) overlapping and collecting the filaments of step B to form a nonwoven web.

[0024] In another embodiment of the invention, a method for preparing segmented non-aqueous polymer microfibers is provided, the method comprising: (A) cutting multi-component fibers into segmented multi-component fibers; (B) contacting a fiber-containing raw material with water to produce a fiber-mixed slurry; wherein the fiber-containing raw material includes segmented multi-component fibers; (C) heating the fiber-mixed slurry to produce a heated fiber-mixed slurry; (D) optionally, mixing the fiber-mixed slurry in a shear zone; (E) removing at least a portion of sulfonated polyester from the multi-component fibers to produce a slurry mixture comprising a sulfonated polyester dispersion and segmented non-aqueous polymer microfibers; and (F) separating the segmented non-aqueous polymer microfibers from the slurry mixture.

[0025] In another embodiment of the invention, a method for producing a microfiber product stream is provided. The method comprises: (A) contacting chopped multicomponent fibers having a length of less than 25 mm with a heated aqueous stream in a fiber opening zone to remove a portion of a water-dispersible sulfonated polyester to produce an opened microfiber slurry; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonated polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonated polyester; wherein the water-dispersible sulfonated polyester is selected from: (1) a water-dispersible sulfonated polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol% of at least one sulfonated monomer; and (c) residues of two or more diols, wherein the diols include 1, 4-Cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (2) a water-dispersible sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein The sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (3) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester The ester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; wherein the heated aqueous stream is at a temperature of at least 40°C; wherein the opened microfiber slurry comprises water, microfibers, and a water-dispersible sulfonyl polyester; and (B) the opened microfiber slurry is fed to a primary solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream; wherein the first mother liquor stream comprises water and a water-dispersible sulfonyl polyester.

[0026] In another embodiment of the invention, another method for producing a microfiber product stream is provided. The method comprises: (A) contacting chopped multicomponent fibers having a length of less than 25 mm with a treated aqueous stream in a fiber slurry zone to produce a chopped multicomponent fiber slurry; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonyl polyester; and wherein the treated aqueous stream is at a temperature below 40°C; wherein the water-dispersible sulfonyl polyester is selected from at least one of: (1) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols contain: The sulfonyl polyester comprises 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; (2) a water-dispersible sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C. The glass transition temperature of the sulfonyl polyester, wherein the sulfonyl polyester contains substantially equimolar amounts of acid moiety repeating units (100 mol percent) and hydroxyl moiety repeating units (100 mol percent), and wherein all said mole percentages are based on the sum of all acid and hydroxyl moiety repeating units equal to 200 mol percent; and (3) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C ... said mole percentages are based on the sum of all acid and hydroxyl moiety repeating units equal to 200 mol percent; and (4) water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicar (A) A high molar ratio of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (B) Contacting a chopped multicomponent fiber slurry with a heated aqueous stream in a fiber opening zone to remove a portion of the water-dispersible sulfonyl polyester to produce an opened microfiber slurry; wherein the opened microfiber slurry comprises non-aqueous polymeric microfibers, water-dispersible sulfonyl polyester, and water; and (C) feeding the opened microfiber slurry to a primary solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream; wherein the first mother liquor stream comprises water and water-dispersible sulfonyl polyester.

[0027] In another embodiment of the invention, another method for producing a microfiber product stream is provided. The method comprises: (A) contacting chopped multicomponent fibers having a length of less than 25 mm with a heated aqueous stream in a mixing zone to produce a chopped multicomponent fiber slurry; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the water-dispersible sulfonyl polyester; wherein the water-dispersible sulfonyl polyester is selected from at least one of: (1) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits at least A glass transition temperature of 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (2) a water-dispersible sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all said acidic and hydroxyl repeating units equaling 200 mol percent; The acid molar repeating unit (100 mol percent) and the hydroxyl molar repeating unit (100 mol percent), wherein all said molar percentages are based on the sum of all acid and hydroxyl molar repeating units equaling 200 mol percent; and (3) a water-dispersible sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar proportions of the acid molar repeating unit (100 mol percent) and the hydroxyl molar repeating unit (100 mol percent) and the hydroxyl molar repeating unit (100 mol percent). (A) A hydroxyl-repeating unit (100 mol percent), wherein all said mol percent is based on the sum of all acids and hydroxyl-repeating units equaling 200 mol percent; and wherein the heated aqueous stream is at a temperature of 40°C or higher; (B) feeding the chopped multicomponent fiber slurry and optionally the heated aqueous stream to a fiber opening zone to remove a portion of the water-dispersible sulfonyl polyester to produce an opened microfiber slurry; wherein the opened microfiber slurry comprises non-water-dispersible polymer microfibers, water-dispersible sulfonyl polyester and water; and (C) feeding the opened microfiber slurry to a primary solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream; wherein the first mother liquor stream comprises water and water-dispersible sulfonyl polyester.

[0028] In another embodiment of the invention, another method for producing a microfiber product stream is provided. The method includes: (A) contacting chopped multicomponent fibers having a length of less than 25 mm with a treated aqueous stream in a fiber slurry zone to produce a chopped multicomponent fiber slurry; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonated polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonated polyester; and wherein the treated aqueous stream is at a temperature below 40°C; (B) contacting the chopped multicomponent fiber slurry with a heated aqueous stream in a mixing zone to produce a heated multicomponent fiber slurry; (C) sending the heated multicomponent fiber slurry to a fiber opening zone to remove a portion of the water-dispersible sulfonated polyester to produce an opened microfiber slurry; and (D) sending the opened microfiber slurry to a primary solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream; wherein the first mother liquor stream comprises water and a water-dispersible sulfonated polyester.

[0029] In another embodiment of the invention, a method for separating a first mother liquor stream is provided. The method includes feeding the first mother liquor stream to a second solid-liquid separation zone to generate a secondary wet filter cake stream and a second mother liquor stream; wherein the second mother liquor stream comprises water and a water-dispersible sulfonated polyester; and wherein the secondary wet filter cake stream comprises non-water-dispersible polymer microfibers.

[0030] In another embodiment of the invention, a method for recovering sulfonated polyester is provided. The method includes: (A) sending a second mother liquor to a primary concentration zone to generate a primary polymer concentrate stream and a primary recovered water stream; and (B) optionally, sending the primary recovered water stream to a fiber opening zone. Attached Figure Description

[0031] Figure 1a , 1b Figures 1 and 1c are cross-sectional views of fibers with three different constructions, specifically illustrating how to determine various measurements related to fiber size and shape.

[0032] Figure 2 This illustrates one embodiment of the invention, wherein the microfiber product stream is generated in a one-step opening zone.

[0033] Figure 3a and 3b This illustrates one embodiment of the invention, wherein the microfiber product stream is generated in a two-step opening zone.

[0034] Figure 4 This illustrates one embodiment of the invention, wherein the microfiber product stream is generated in a three-step opening zone.

[0035] Figure 5 An embodiment of a method for cutting multicomponent fibers to produce chopped multicomponent fibers is shown.

[0036] Figure 6a An embodiment of the opening zone is shown, wherein the opening zone includes a tube.

[0037] Figure 6b An embodiment of the opening zone is shown, wherein the opening zone includes a continuous stirring vessel.

[0038] Figure 6c An embodiment of the opening zone is shown, wherein the opening zone includes more than one continuous stirring vessel.

[0039] Figure 7a and 7b An embodiment of the primary solid-liquid separation zone is shown. Detailed Implementation

[0040] Inventive sulfonyl polyester

[0041] This invention provides a novel water-dispersible sulfonyl polyester having a glass transition temperature of at least 57°C and being dispersible in water at temperatures below about 90°C. This novel sulfonyl polyester is particularly suitable for producing multicomponent fibers, in which excellent removability is combined with anti-blocking properties.

[0042] In one embodiment of the present invention, a water-dispersible sulfonyl polyester is provided, comprising:

[0043] (a) One or more dicarboxylic acid residues;

[0044] (b) at least 10 molar percentages of residues of at least one sulfonyl monomer; and

[0045] (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol.

[0046] Among them, sulfonyl polyesters exhibit a glass transition temperature of at least 57°C.

[0047] The sulfonyl polyester contains essentially equimolar amounts of acid-repeating units (100 mol percent) and hydroxyl-repeating units (100 mol percent), and

[0048] All the molar percentages mentioned herein are based on the sum of all repeating units of the acid and hydroxyl groups being equal to 200 molar percentages.

[0049] In another embodiment of the invention, a water-dispersible sulfonyl polyester is provided, comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all of the molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages.

[0050] In another embodiment of the invention, a water-dispersible sulfonyl polyester is provided, comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent.

[0051] These sulfonyl polyesters of the present invention have a Tg greater than 57°C, which helps prevent fiber adhesion when formed into fibers. Furthermore, these sulfonyl polyesters of the present invention exhibit excellent dispersibility individually in water at temperatures below 90°C, forming a dispersion of at least 5 wt% sulfonyl polyester. This provides cost savings in process operation because no additional chemicals, such as strong alkalis, are required to disperse the sulfonyl polyester in water. Similarly, the lower temperature will also save on operating costs.

[0052] The sulfonyl polyester of the present invention comprises dicarboxylic acid monomer residues, sulfonyl monomer residues, diol monomer residues, and repeating units. The sulfonyl monomer can be a dicarboxylic acid, a diol, or a hydroxycarboxylic acid. Therefore, the term "monomer residue" as used herein refers to a residue of a dicarboxylic acid, a diol, or a hydroxycarboxylic acid. The term "repeating unit" as used herein refers to an organic structure having two monomer residues bonded by a carbonyl group. The sulfonyl polyester of the present invention contains substantially equal molar amounts of acid residues (100 mol%) and diol residues (100 mol%), which react in substantially equal proportions such that the total molar number of repeating units is equal to 100 mol%. Therefore, the molar percentages provided in this disclosure can be based on the total molar number of acid residues, the total molar number of diol residues, or the total molar number of repeating units. For example, based on the total repeating units, a sulfonyl polyester containing 30 mol% of a sulfonyl monomer, which can be a dicarboxylic acid, a diol, or a hydroxycarboxylic acid, means that the sulfonyl polyester contains 30 mol% of a sulfonyl monomer in a total of 100 mol% repeating units. Therefore, 30 moles of sulfonyl monomer residues are present in every 100 moles of repeating units. Similarly, based on total acid residues, a sulfonated polyester containing 30 mol% of dicarboxylic acid sulfonated monomers means that the sulfonated polyester contains 30 mol% of sulfonated monomers out of a total of 100 mol% acid residues. Therefore, in the latter case, there are 30 mol of sulfonated monomer residues per 100 mol of acid residues.

[0053] The sulfonyl polyesters described herein have a specific logarithmic viscosity, hereinafter abbreviated as "Ih.V.", of at least 0.1, 0.15, 0.2, 0.25, or 0.3 and / or less than 0.8, 0.7, 0.6, 0.5, or 0.45 dL / g, measured at 25°C and at a concentration of 0.5 g of sulfonyl polyester in 100 ml of solvent in 60 / 40 parts by weight of phenol / tetrachloroethane solvent.

[0054] Molecular weight is conveniently described by "specific logarithmic viscosity," abbreviated as IhV, which is measured in a 60 / 40 w / w solution of phenol / tetrachloroethane at a concentration of 0.5 g of sulfonyl polyester in 100 mL of solvent at 25 °C. At IhV below 0.1, compositional inhomogeneity and generally low molecular weight can lead to problems such as poor film formation, non-dispersible fractions, reduced usability, and poor storage stability. The specific logarithmic viscosity (IhV) of these polyesters is a useful specification of molecular weight, determined according to ASTM D2857-70 method in a Wagner viscometer of Lab Glass, Inc. with a 1 / 2 mL capillary bulb, using approximately 0.5 wt% polymer concentration in a 60 / 40 wt% phenol / tetrachloroethane solution. This method is performed by heating the polymer / solvent system at 120 °C for 15 minutes, cooling the solution to 25 °C, and measuring the flow time at 25 °C. IV is calculated by the following equation:

[0055]

[0056] in:

[0057] η: Specific logarithmic viscosity at 25°C at a polymer concentration of 0.5 g / 100 mL solvent;

[0058] t S Sample flow time;

[0059] T0: Blank solvent flow time;

[0060] C: Polymer concentration (0.5) based on g / 100 mL solvent.

[0061] Throughout this application, the unit for specific logarithmic viscosity is deciliters per gram.

[0062] In the following embodiments, the viscosity of tetrachloroethane / phenol (60 / 40, by weight) was measured at 25°C and calculated according to the following formula:

[0063]

[0064] Where, η sp It refers to specific viscosity, and C is concentration. The unit of IhV is deciliters per gram (dg).

[0065] The molecular weight of sulfonated polyesters is related to their melt viscosity, which is important for melt-spun fibers.

[0066] As used herein, the term "polyester" includes both "homogeneous polyester" and "copolyester," and refers to a synthetic polymer prepared by the polycondensation of a difunctional carboxylic acid with a difunctional hydroxyl compound. As used herein, the term "sulfonyl polyester" refers to any polyester containing a sulfonyl monomer. Typically, the difunctional carboxylic acid is a dicarboxylic acid, and the difunctional hydroxyl compound is a dihydroxyl alcohol, such as ethylene glycol and glycol. As used herein, the term "residue" refers to any organic structure introduced into the polymer through a polycondensation reaction involving the respective monomer. Thus, a dicarboxylic acid residue can be derived from a dicarboxylic acid monomer or its associated acyl halide, ester, salt, anhydride, or mixture thereof. Therefore, as used herein, the term dicarboxylic acid is intended to include dicarboxylic acids and any derivatives thereof, including their associated acyl halide, ester, half-ester, salt, half-salt, anhydride, mixed anhydride, or mixture thereof, which can be used in a polycondensation process with a glycol to prepare a high molecular weight polyester.

[0067] The sulfonated polyester of the present invention comprises one or more dicarboxylic acid residues. Depending on the type and concentration of the sulfonated monomer, the dicarboxylic acid residues may comprise about 60 to about 100 mol% of the acid residues. Other examples of concentration ranges for the dicarboxylic acid residues are about 60 mol% to about 96 mol% and about 70 mol% to about 96 mol%. Examples of usable dicarboxylic acids include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, or mixtures of two or more of these acids. Thus, suitable dicarboxylic acids include, but are not limited to: succinic acid; glutaric acid; adipic acid; azelaic acid; sebacic acid; fumaric acid; maleic acid; itaconic acid; 1,3-cyclohexanedicarboxylic acid; 1,4-cyclohexanedicarboxylic acid; diethylene glycol; 2,5-norbornenedicarboxylic acid; phthalic acid; terephthalic acid; 1,4-naphthalenedicarboxylic acid; 2,5-naphthalenedicarboxylic acid; biphenyl; 4,4'-dibenzoic acid; 4,4'-sulfonyldibenzoic acid; and isophthalic acid. Preferred dicarboxylic acid residues are isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid, or, if diesters are used, dimethyl terephthalate, dimethyl isophthalate, and dimethyl 1,4-cyclohexanedicarboxylic acid, wherein isophthalic acid and terephthalic acid residues are particularly preferred. Although methyl dicarboxylic acid esters are the most preferred embodiment, higher alkyl esters such as ethyl, propyl, isopropyl, butyl, etc., are also acceptable. Additionally, aromatic esters, particularly phenyl esters, may also be used. In one embodiment, the sulfonyl polyester comprises one or more residues of dicarboxylic acids derived from terephthalic acid, isophthalic acid, or combinations thereof.

[0068] The sulfonated polyester comprises residues of at least one sulfonated monomer, based on about 4 to about 40 mol% of the total repeating units, wherein the monomer has two functional groups and one or more sulfonate groups attached to an aromatic or alicyclic ring, wherein the functional group is a hydroxyl, a carboxyl, or a combination thereof. Other examples of concentration ranges for the sulfonated monomer residues are about 4 to about 35 mol%, about 8 to about 30 mol%, and about 8 to about 25 mol%, based on the total repeating units. In another embodiment, the amount of the sulfonated monomer is 4, 5, 6, 7, 8, 8.5, 9, 9.5, 10, 11, 12, 13, or 14 mol percent and / or less than 40, 35, 30, 25, or 20 mol percent of the sulfonated monomer, based on the total repeating units. In another embodiment, the amount of the sulfonated monomer is at least 10, 11, 12, 13, or 14 mol percent and / or less than 40, 35, 30, 25, or 20 mol percent, based on the total repeating units.

[0069] The sulfonyl monomer can be a dicarboxylic acid or its ester containing a sulfonate group, a diol containing a sulfonate group, or a hydroxy acid containing a sulfonate group. The term "sulfonate" refers to a sulfonate having the structure "-SO3M", where M is the cation of the sulfonate. The cation of a sulfonate can be a metal ion, such as Li. + Na + or K+ Alternatively, the cation of the sulfonate can be nonmetallic, such as a nitrogen-containing base as described in U.S. Patent No. 4,304,901. The nitrogen-containing cation is derived from a nitrogen-containing base, which can be aliphatic, alicyclic, or aromatic compounds. Examples of such nitrogen-containing bases include ammonia, dimethylethanolamine, diethanolamine, triethanolamine, pyridine, morpholine, and piperidine. Because monomers containing nitrogen-containing sulfonates are generally thermally unstable under the conditions required to prepare polymers in melt form, the method of the present invention for preparing sulfonated polyesters containing nitrogen-containing sulfonate groups involves dispersing, dissipating, or dissolving a polymer containing a desired amount of sulfonate groups in water as an alkali metal salt, followed by exchanging the alkali metal cation with a nitrogen-containing cation.

[0070] When a monovalent alkali metal ion is used as the cation of the sulfonate, the resulting sulfonated polyester is completely dispersible in water, with the dispersion rate depending on the content of the sulfonate monomer in the polymer, the water temperature, the surface area / thickness of the sulfonate, etc. It is possible to use more than one counterion in a single polymer composition, and methods for adjusting or fine-tuning the water responsiveness of the resulting product can be provided. Examples of sulfonate monomer residues include monomer residues in which the sulfonate group is attached to an aromatic or alicyclic ring or residue of an aromatic dicarboxylic acid, such as a benzene ring; naphthalene; biphenyl; oxybiphenyl; sulfonylbiphenyl; and methylene diphenyl or cycloaliphatic rings, such as cyclohexyl; cyclopentyl; cyclobutyl; cycloheptyl; and cyclooctyl. Other examples of sulfonate monomer residues that can be used in this invention are metal sulfonates of sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid, or combinations thereof. Other examples of sulfonate monomers that can be used are 5-sodium sulfoisophthalic acid and its esters. If the sulfonyl monomer residues are derived from 5-sodium sulfoisophthalic acid, the typical sulfonyl monomer concentration range is about 4 to about 35 mol%, about 8 to about 30 mol%, and about 8 to 25 mol%, based on the total number of moles of acid residues.

[0071] The sulfonyl monomers used to prepare sulfonyl polyesters are known compounds and can be prepared using methods well-known in the art. For example, sulfonyl monomers wherein the sulfonate group is attached to an aromatic ring can be prepared by sulfonating an aromatic compound with fuming sulfuric acid to obtain the corresponding sulfonic acid, followed by reaction with a metal oxide or a base such as sodium acetate to prepare the sulfonate. Methods for preparing various sulfonyl monomers are described, for example, in U.S. Patent Nos. 3,779,993; 3,018,272; and 3,528,947.

[0072] When the polymer is in dispersion form, sulfonated polyesters can also be prepared by using, for example, sodium sulfonate and ion exchange methods to replace sodium with different ions such as lithium.

[0073] The sulfonyl polyester of the present invention comprises residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol. In one embodiment, the sulfonyl polyester comprises a diethylene glycol residue to a 1,4-cyclohexanediethanol residue in a molar ratio of less than 1:1, less than 0.75:1, less than 0.5:1, or less than 0.25:1. The sulfonyl polyester may comprise at least 20, 25, 30, 35, 40, 45, 50, 55, or 60 molar percentages and / or no more than 99, 95, 90, 85, or 80 molar percentages of 1,4-cyclohexanediethanol residues. In another embodiment, the sulfonyl polyester may be free of any ethylene glycol residues.

[0074] The sulfonyl polyester of the present invention may also contain other diols and diethylene glycols besides 1,4-cyclohexanediethanol. The sulfonyl polyester may include one or more diol residues, which may include aliphatic, alicyclic, and aralkyl diols. Alicyclic diols, such as 1,3- and 1,4-cyclohexanediethanol, may be present in their pure cis or trans isomers or in mixtures of cis and trans isomers. As used herein, the term "diol" is synonymous with the term "glycol" and refers to any diol. Examples of diols include, but are not limited to, ethylene glycol; triethylene glycol; polyethylene glycol; 1,3-propanediol; 2,4-dimethyl-2-ethylhexyl-1,3-diol; 2,2-dimethyl-1,3-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; 2,2,4-trimethyl-1,6-hexanediol; thiodiethanol; 1,2-cyclohexanediol; 1,3-cyclohexanediol; 2,2,4,4-tetramethyl-1,3-cyclobutanediol; p-xylenediol; or one or more combinations of these diols.

[0075] Diol residues may include those with the structure H-(OCH2-CH2). n The -OH residue of polyethylene glycol, where n is an integer from 3 to about 500. Non-limiting examples of low molecular weight polyethylene glycols are triethylene glycol and tetraethylene glycol, for example, where n is from 3 to 6. Higher molecular weight polyethylene glycols (abbreviated herein as "PEG"), where n is from 7 to about 500, include commercially available known names such as This product is from Dow Chemical Company (formerly Union Carbide). Typically, PEG is used in combination with other diols such as diethylene glycol or ethylene glycol. Based on the value of n, which ranges from greater than 6 to 500, the molecular weight can range from greater than 300 to approximately 22,000 g / mol. Molecular weight and mol% are inversely proportional; specifically, as the molecular weight increases, the mol% decreases to achieve the specified level of hydrophilicity.

[0076] Due to side reactions that can be controlled by altering process conditions, certain dimer, trimer, and tetramer diols can be formed in situ. For example, varying amounts of diethylene glycol, triethylene glycol, and tetraethylene glycol can be formed from ethylene glycol via an acid-catalyzed dehydration reaction, which readily occurs when the polycondensation reaction is carried out under acidic conditions. Buffer solutions known to those skilled in the art can be added to the reaction mixture to delay these side reactions. However, other compositional ranges are possible if the buffer solution is omitted and dimerization, trimerization, and tetramerization are allowed to proceed.

[0077] The sulfonyl polyesters of the present invention may comprise residues of a branched monomer having three or more functional groups, based on 0 to 25 mol% of total repeating units, wherein the functional groups are hydroxyl, carboxyl, or combinations thereof. Non-limiting examples of branched monomers are 1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, glycerol, pentaerythritol, erythritol, threitol, dipentaerythritol, sorbitol, trimellitic anhydride, pyromellitic dianhydride, dimethylolpropionic acid, or combinations thereof. Other examples of branched monomer concentration ranges are 0 to 20 mol% and 0 to 10 mol%. The presence of branched monomers can lead to many possible benefits of the sulfonyl polyesters of the present invention, including but not limited to the ability to modulate rheological, solubility, and stretching properties. For example, at a constant molecular weight, branched sulfonyl polyesters will also have a higher concentration of end groups compared to linear analogs, which can promote post-polymerization crosslinking reactions. However, at high concentrations of branching agents, sulfonyl polyesters may tend to gel.

[0078] The sulfonyl polyester used in this invention has a glass transition temperature, abbreviated herein as "Tg," of at least 57°C, which is measured on a dry polymer using a standard technique of differential scanning calorimetry ("DSC") as well known to those skilled in the art. The Tg measurement of the sulfonyl polyester of this invention is performed using a "dry polymer," i.e., a polymer sample in which foreign or absorbed water is dissipated by heating the polymer to a temperature of about 200°C and allowing the sample to return to room temperature. Typically, the sulfonyl polyester is dried in a DSC apparatus by performing a first thermal scan in which the sample is heated to a temperature above the vaporization temperature of water, held at that temperature until the vaporization of water absorbed in the polymer is complete (as indicated by a large, broad endothermic reaction), cooling the sample to room temperature, and then performing a second thermal scan to obtain the Tg measurement. In another embodiment of the invention, the sulfonated polyester exhibits a glass transition temperature of at least 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 75°C, 80°C, 85°C, or 90°C and / or less than 120°C, 115°C, 110°C, 105°C, 100°C, 95°C, or 90°C.

[0079] When sulfonyl polyester is added to pure water at 90°C for at least 5 minutes under constant stirring, the sulfonyl polyester of the present invention can form an aqueous dispersion containing at least 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5% by weight of sulfonyl polyester.

[0080] Preparation method of sulfonyl polyester

[0081] The sulfonated polyesters of the present invention, using typical polycondensation reaction conditions, are readily prepared from suitable dicarboxylic acids, esters, anhydrides, or salts, sulfonated monomers, and suitable diols or mixtures of diols. They can be prepared by continuous, semi-continuous, and batch operations and can utilize a variety of reactor types. Examples of suitable reactor types include, but are not limited to, stirred tank reactors, continuous stirred tank reactors, slurry reactors, tubular reactors, scraped film reactors, falling film reactors, or extrusion reactors. The term “continuous,” as used herein, refers to a method in which the introduction of reactants and the recovery of products are carried out simultaneously in a non-interrupted manner. “Continuous” means that the method is substantially or completely continuous in operation, in contrast to a “batch” method. “Continuous” does not in any way imply the prohibition of normal interruptions in a continuous method due to, for example, start-up, reactor maintenance, or predetermined shutdown cycles. The term “batch” as used herein refers to a method in which all reactants are added to a reactor and subsequently processed according to a predetermined reaction process, during which no clumps are fed into or removed from the reactor. The term "semi-continuous" refers to a method in which some reactants are added at the beginning of the method, while the remaining reactants are continuously fed as the reaction progresses. Alternatively, a semi-continuous process may also include a method similar to a batch process, in which all reactants are added at the beginning of the method, except that one or more products are continuously removed as the reaction progresses. Operating the method as a continuous process is advantageous for economic reasons and to produce a desirable color for the polymer, as the appearance may deteriorate if the sulfonyl polyester is held in the reactor at high temperatures for too long.

[0082] The sulfonated polyesters of the present invention are prepared by methods known to those skilled in the art. The sulfonated monomer is most typically added directly to the reaction mixture to prepare the polymer, but other methods are known and can be used, for example, as described in U.S. Patent Nos. 3,018,272, 3,075,952, and 3,033,822. The reaction of the sulfonated monomer, diol component, and dicarboxylic acid component can be carried out using conventional polyester polymerization conditions. For example, when preparing the sulfonated polyester via transesterification, i.e., from the ester form of the dicarboxylic acid component, the reaction process can include two steps. In the first step, the diol component and the dicarboxylic acid component, such as dimethyl isophthalate, are reacted at a temperature typically from about 150°C to about 250°C for about 0.5 to about 8 hours, at a pressure from about 0.0 kPa gauge pressure to about 414 kPa gauge pressure (60 psig). Preferably, the transesterification reaction is carried out at a temperature of about 180°C to about 230°C for about 1 to about 4 hours, and at a preferred pressure of about 103 kPa gauge pressure (15 psig) to about 276 kPa gauge pressure (40 psig). Subsequently, the reaction product is heated at a higher temperature and a lower pressure to form a sulfonyl polyester with eliminated diols, which is readily volatile under these conditions and is removed from the system. This second step, or polycondensation step, continues under a higher vacuum and a certain temperature, typically about 230°C to about 350°C, preferably about 250°C to about 310°C and most preferably about 260°C to about 290°C for about 0.1 to about 6 hours, or preferably about 0.2 to about 2 hours, until a polymer with the desired degree of polymerization, as determined by the logarithmic viscosity, is obtained. The polycondensation step can be carried out at a reduced pressure of about 53 kPa (400 Torr) to about 0.013 kPa (0.1 Torr). Stirring or suitable conditions are used in the two-stage process to ensure adequate heat transfer and surface renewal of the reaction mixture. The two-stage reaction can be promoted by suitable catalysts, such as alkoxytitanium compounds, alkali metal hydroxides and alkoxides, salts of organic carboxylic acids, alkyltin compounds, metal oxides, etc. Three-stage manufacturing methods, similar to those described in U.S. Patent No. 5,290,631, can also be used, particularly when using a mixed monomer feed of acids and esters.

[0083] To ensure that the reaction between the diol and dicarboxylic acid components is carried out via an transesterification mechanism, a ratio of about 1.05 to about 2.5 moles of diol component to one mole of dicarboxylic acid component is preferred. However, those skilled in the art will understand that the ratio of diol component to dicarboxylic acid component is typically determined by the design of the reactor in which the reaction process takes place.

[0084] In the preparation of sulfonyl polyesters via direct esterification, i.e., starting from an acidic dicarboxylic acid component, sulfonyl polyesters are produced by reacting a dicarboxylic acid or a mixture of dicarboxylic acids with a diol component or a mixture of diol components. The reaction is carried out under pressures of about 7 kPa gauge pressure (1 psig) to about 1379 kPa gauge pressure (200 psig), preferably less than 689 kPa (100 psig), to produce low molecular weight linear or branched sulfonyl polyester products having an average degree of polymerization of about 1.4 to about 10. The temperature used during the direct esterification reaction is generally about 180°C to about 280°C, more preferably about 220°C to about 270°C. This low molecular weight polymer can then be polymerized by a polycondensation reaction.

[0085] End uses of sulfonyl polyester

[0086] The water-dispersible sulfonyl polyester of the present invention can be used in any end-use application known in the art. For example, the water-dispersible sulfonyl polyester can be used in paints and coatings, inks, adhesives, plastics, films, and personal care products. Personal care products include, but are not limited to, cosmetics, hair products, lotions, and sunscreens. In one embodiment of the invention, the sulfonyl polyester of the present invention is used as a primer for biaxially oriented PET for flexible packaging or as a coating on aluminum foil. The sulfonyl polyester provides good adhesion and can be water- and alcohol-resistant. The sulfonyl polyester of the present invention is also low in odor. The water-dispersible sulfonyl polyester of the present invention is often used in the form of dispersions for various end-use applications. The amount of sulfonyl polyester in the dispersion is about 15 to about 35% by weight, about 20 to about 30% by weight, and about 24 to about 27% by weight.

[0087] Fibers containing inventive sulfonated polyester

[0088] The inventive sulfonated polyester of this invention can be spun into water-dispersible fibers and fiber articles, which exhibit tensile strength, absorbency, flexibility, and fabric integrity in the presence of moisture, particularly human bodily fluids. The fibers and fiber articles of this invention do not require the presence of oils, waxes, or fatty acid finishing agents, or the use of large amounts (typically 10% by weight or more) of pigments or fillers to prevent the fibers from sticking or fusing during processing. Furthermore, fiber articles prepared from the novel fibers of this invention do not require adhesives and are easily dispersed or dissolved in domestic or public drainage systems.

[0089] The fiber may optionally comprise a water-dispersible polymer blended with a sulfonated polyester and a non-water-dispersible polymer blended with a sulfonated polyester, provided that the blend is immiscible. The fiber may contain less than 10% by weight of pigment or filler, based on the total weight of the fiber. The invention also includes fiber articles comprising these fibers and may have one or more fiber absorbent layers.

[0090] The sulfonyl polyester of the present invention can be used to produce single-component, bicomponent, or multicomponent fibers. For the purposes of this invention, the term "fiber" refers to a polymeric object with a high aspect ratio capable of being shaped into two-dimensional or three-dimensional articles, such as woven or nonwoven fabrics. Within the scope of this invention, the term "fiber" is synonymous with "fibers" and is intended to refer to one or more fibers. The fibers of the present invention can be single-component, bicomponent, or multicomponent fibers. The term "unicomponent fiber," as used herein, refers to a fiber prepared by melt spinning a single sulfonyl polyester or a blend of one or more sulfonyl polyesters, or a blend of one or more sulfonyl polyesters with one or more other polymers, and includes staple fibers, monofilament fibers, and multifilament fibers. "Unicomponent" is intended to be synonymous with the term "monocomponent" and includes "bicomponent" or "multicomponent" fibers, which are fibers formed from at least two polymers extruded from the same extruder in the form of a mixture. Single-component or bicomponent fibers do not have various polymer components arranged in different regions of a relatively constant configuration along the cross-section of the fiber, and the various polymers are generally discontinuous along the entire length of the fiber, instead typically forming filaments or fibrils with arbitrary beginnings and ends. Therefore, the term "single-component" is not intended to exclude fibers formed from such polymers or blends of one or more polymers, to which small amounts of additives may be added for coloring, antistatic properties, lubrication, hydrophilicity, etc.

[0091] In contrast, the term "multicomponent fiber," as used herein, is intended to refer to fibers prepared by melting two or more fiber-forming polymers in separate extruders, guiding the resulting multiple polymer streams into a spinneret with multiple distributed flow paths, but spinning them together to form a single fiber. Multicomponent fibers are sometimes also referred to as conjugated or bicomponent fibers. The polymers are arranged in substantially fixed segments or regions along the cross-section of the conjugated fiber and extend continuously along the length of the conjugated fiber. The configuration of such multicomponent fibers can be, for example, a sheath / core structure, in which one polymer is surrounded by another, or it can be a side-by-side structure, a disc structure, or a "sea-of-island" structure. For example, multicomponent fibers can be prepared by individually extruding a sulfonated polyester and one or more non-aqueous polymers through a spinneret having a shaped or processed cross-sectional geometry, such as a "sea-of-island" or fan-shaped configuration. Typically, multicomponent fibers are short fibers, monofilaments, or multifilaments with a shaped or circular cross-section. Most fiber forms are heat-set. Fibers may include a variety of antioxidants, pigments, and additives, as described herein.

[0092] For example, the fibers of the present invention can be prepared by melt spinning a single sulfonyl polyester or a sulfonyl polyester blend, and include short fibers, monofilaments, and multifilaments with shaped cross sections. Furthermore, our invention provides multicomponent fibers, such as those described in U.S. Patent No. 5,916,678, which can be prepared by separately passing a sulfonyl polyester and one or more non-aqueous dispersible polymers immiscible with the sulfonyl polyester through a spinneret having a shaped or processed cross-sectional geometry, such as an "island-type," core-sheath type, side-by-side type, ribbon (strip) type, or fan-shaped configuration. The sulfonyl polyester can then be removed by dissolving the interfacial layer or fan-shaped segments, leaving smaller filaments or microdenier fibers of the non-aqueous dispersible polymer. These fibers of the non-aqueous dispersible polymer have a much smaller fiber size than the multicomponent fibers before the sulfonyl polyester is removed. For example, the sulfonyl polyester and the non-aqueous dispersible polymer can be fed into a polymer distribution system, where the polymer is introduced into segmented spinnerets. The polymer reaches the fiber spinneret along separate paths and combines at the spinneret orifice, which comprises two concentric circular holes to provide a core-sheath type fiber, or comprises a circular spinneret orifice divided into multiple sections along its diameter to provide fibers with a side-by-side configuration. Alternatively, immiscible water-dispersible sulfonyl polyesters and non-water-dispersible polymers can be separately introduced into a spinneret having multiple radial channels to produce multicomponent fibers with a fan-shaped cross-section. Typically, the sulfonyl polyester will form the "sheath" component of the core-sheath configuration. In the fiber cross-section having multiple segments, the non-water-dispersible segments are typically substantially isolated from each other by the sulfonyl polyester. Alternatively, multicomponent fibers can be formed by melting the sulfonyl polyester and non-water-dispersible polymer in a separate extruder and directing the polymer flow into a spinneret having multiple distributed flow paths in the form of small tubes or segments to provide fibers with an island-shaped cross-section. An example of such a spinneret is described in U.S. Patent 5,366,804. In this invention, typically, the sulfonyl polyester will form the "sea" component, and the non-water-dispersible polymer will form the "island" component.

[0093] Monocomponent fibers, fiber articles made from monocomponent fibers, and the sulfonated polyester portion of multicomponent fibers, or articles containing multicomponent fibers, are water-dispersible and are generally completely dispersed at room temperature. Higher water temperatures can be used to accelerate their dispersibility or removal rate from nonwoven or multicomponent fibers. As used herein, the term "water-dispersible" is used in relation to monocomponent fibers and fiber articles made from monocomponent fibers and is synonymous with the terms "water dissolvability," "water decomposition," "water-dissolvable," "water-dispersible," "water-removable," "hydrosoluble," and "hydrodispersible," meaning that the fiber or fiber article is dispersed or dissolved in or by means of water. The terms “dispersible,” “dispersible,” “dissipable,” or “dissipable” refer to the formation of a loose suspension or slurry of fibers or fiber articles using a sufficient amount of deionized water (e.g., a 100:1 weight ratio of water to fiber) at a temperature of about 60°C for a period of up to 5 days, in which the fibers or fiber articles dissolve, disintegrate, or separate into multiple, more or less incoherent flakes or particles distributed throughout the medium, such that identifiable filaments cannot be recovered from the medium upon removal of water (e.g., by filtration or evaporation). Therefore, “water dispersibility” as used herein is not intended to include the simple disintegration of entangled or bound, but water-insoluble or non-dispersible aggregates of fibers, wherein the fiber aggregates simply break apart in water, producing a slurry of fibers in water that can be recovered by removal of water. In the context of this invention, all these terms refer to the activity of water or a mixture of water and a water-miscible cosolvent towards the sulfonated polyesters described herein. Examples of such water-miscible cosolvents include alcohols, ketones, glycol ethers, esters, etc. The term is intended to include both conditions under which sulfonyl polyesters dissolve to form a true solution and conditions under which sulfonyl polyesters are dispersed in an aqueous medium. Typically, due to the statistical properties of sulfonyl polyester compositions, when a single sulfonyl polyester sample is placed in an aqueous medium, it may exhibit both soluble and dispersed fractions.

[0094] Similarly, as used herein, the term "water dispersibility" in relation to sulfonyl polyester as a component of a multicomponent fiber or fiber article is intended to be synonymous with the terms "water dissipability," "water decomposition," "water-dissolvable," "water-dispersible," "water-removable," "hydraulic solubility," and "hydraulic dispersibility," and is intended to mean that the sulfonyl polyester component is sufficiently removed from the multicomponent fiber and dispersed or dissolved by the action of water, thereby enabling the release and separation of the non-water-dispersible fibers contained therein. The terms "dispersible," "dispersible," "dissipable," or "dissipable" refer to the dissolution, disintegration, or separation of the sulfonyl polyester component from the multicomponent fiber, leaving multiple microdenier fibers from the non-water-dispersible segment, in a loose suspension or slurry of the fiber or fiber article formed using a sufficient amount of deionized water (e.g., 100:1 water:fiber by weight) at a temperature of approximately 60°C and over a period of up to 5 days.

[0095] The terms “segment,” “domain,” or “region,” when used to describe the formed cross-section of a multicomponent fiber, refer to a region within the cross-section containing a non-aqueous polymer, wherein these domains or segments are substantially isolated from each other by water-dispersible sulfonyl polyesters inserted between the segments or domains. As used herein, the term “substantially separated” is intended to indicate that the segments or domains are separated from each other to allow the segmental sulfonyl polyester domains to form individual fibers upon removal of the sulfonyl polyester. Segments, domains, or regions may have similar or different sizes and shapes. Again, segments, domains, or regions may be arranged in any configuration. These segments, domains, or regions are “substantially continuous” along the length of the multicomponent extrusion or fiber. The term “substantially continuous” means continuous along at least 10 cm of the multicomponent fiber. When the water-dispersible sulfonyl polyester is removed, these segments, domains, or regions of the multicomponent fiber produce non-aqueous polymer microfibers.

[0096] As described in this disclosure, the forming cross section of multi-component fibers can be, for example, core-sheath type, island type, fan-shaped type, hollow fan-shaped type; eccentric fan-shaped type, parallel type, strip type, etc.

[0097] However, in another embodiment, the sulfonyl polyester of the present invention may be a single polyester or may be blended with one or more supplementary polymers to modify the properties of the resulting fiber. The supplementary polymer may or may not be water-dispersible, depending on the application, and may be miscible or immiscible with the sulfonyl polyester. If the supplementary polymer is not water-dispersible, the blend with the sulfonyl polyester is preferably immiscible. As used herein, the term "miscible" means that the blend has a single, homogeneous amorphous phase, as indicated by a single composition-dependent Tg. For example, as shown in U.S. Patent 6,211,309, a first polymer miscible with the second polymer can be used to "plasticize" the second polymer. Conversely, the term "immiscible" as used herein refers to a blend exhibiting at least two randomly mixed phases and exhibiting more than one Tg. Some polymers may be immiscible but compatible with the sulfonyl polyester. Further general descriptions of miscible and immiscible polymer blends and various analytical techniques for characterizing them can be found in Polymer Blends Volumes 1 and 2, Bucknall, 2000, edited by DR. Paul and C.B. Bucknall, John Wiley & Sons, Inc.

[0098] Non-limiting examples of water-dispersible polymers that can be blended with sulfonated polyesters are polymethacrylic acid, polyvinylpyrrolidone, polyethylene-acrylic acid copolymer, polyethylene methyl ether, polyvinyl alcohol, polyethylene oxide, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl hydroxyethyl cellulose, isopropyl cellulose, methyl ether starch, polyacrylamide, poly(N-vinylcaprolactam), polyethyl oxazoline, poly(2-isopropyl-2-oxazoline), polyvinylmethyl oxazoline, water-dispersible sulfonated polyester, polyvinylmethyl oxazoline, poly(2,4-dimethyl-6-triazine ethylene), and ethylene oxide-propylene oxide copolymer. Examples of non-aqueous dispersible polymers that can be blended with sulfonated polyesters include, but are not limited to: polyolefins, such as homopolymers and copolymers of polyethylene and polypropylene; poly(ethylene terephthalate); poly(butylene terephthalate); and polyamides, such as nylon-6; polylactic acid; caprolactone; Eastar Bio (poly(tetramethylene adipate-co-terephthalate), a product of Eastman Chemical Company); polycarbonate; polyurethane; and polyvinyl chloride.

[0099] According to the invention, blends of more than one sulfonyl polyester can be used to adjust the end-use properties of the resulting fibers or fiber articles, such as nonwoven fabrics or webs. The Tg of the blend of one or more sulfonyl polyesters is at least 57°C. Therefore, blending can also be used to modify the processing characteristics of the sulfonyl polyester to facilitate the manufacture of nonwovens. In another example, an immiscible blend of polypropylene and sulfonyl polyester can provide a conventional nonwoven web that will split and be completely dispersed in water, as true solubility is not required. In a later embodiment, the desired properties involve maintaining the physical properties of the polypropylene, while the sulfonyl polyester is merely a bystander in the actual use of the product, or the sulfonyl polyester is short-lived and removed before the final form of the product is used.

[0100] Sulfonated polyesters and complementary polymers can be blended using intermittent, semi-continuous, or continuous methods. Small-scale batches can be readily prepared in any high-intensity mixing equipment known to those skilled in the art, such as a Banbury mixer, prior to melt spinning. These components can also be blended in solution in a suitable solvent. Melt blending methods involve blending sulfonated polyesters and complementary polymers at temperatures sufficient to melt the polymer. The blends can be cooled and granulated for further use, or the melt blends can be melt-spun directly from the melt blend into fiber form. The term "melt" as used herein includes, but is not limited to, simply softening the polyester. For melt blending methods generally known in the polymer field, see Mixing and Compounding of Polymers (edited by I. Manas-Zlockower & Z. Tadmor, Carl Hanser Verlag, 1994, New York).

[0101] Water-dispersible sulfonated polyesters, single-component, multi-component, and chopped fibers, as well as fiber products made therefrom, may also contain other conventional additives and ingredients that do not adversely affect their end use. For example, additives such as fillers, surface friction modifiers, light and heat stabilizers, extrusion aids, antistatic agents, colorants, dyes, pigments, fluorescent whitening agents, antimicrobial agents, anti-counterfeiting marks, hydrophobic and hydrophilic reinforcing agents, viscosity modifiers, slip agents, toughening agents, and adhesion promoters may be used.

[0102] The fibers and fiber articles of the present invention do not require the presence of additives, such as pigments, fillers, oils, waxes, or fatty acid finishing agents, to prevent the fibers from sticking together or fusing during processing. The term "sticking together or fusing" as used herein should be understood to mean that the fibers or fiber articles adhere together or fuse into clumps, making the fibers unprocessable or unsuitable for their intended purpose. Sticking and fusing can occur during the processing of the fibers or fiber articles or during storage over several days or weeks, and are exacerbated under hot and humid conditions.

[0103] In one embodiment of the invention, the fibers and fiber articles will contain less than 10% by weight of this anti-blocking additive, based on the total weight of the fibers or fiber articles. For example, the fibers and fiber articles may contain less than 10% by weight of pigment or filler. In other instances, the fibers and fiber articles may contain less than 9% by weight, less than 5% by weight, less than 3% by weight, less than 1% by weight, and 0% by weight of pigment or filler based on the total weight of the fibers. Colorants, sometimes referred to as colorants, may be added to impart a desired neutral hue and / or brightness to the sulfonated polyester. When coloring of the fibers is required, the pigments or colorants may be included in the sulfonated polyester reaction mixture during the reaction of the diol monomer and the dicarboxylic acid monomer, or they may be melt-blended with a pre-formed sulfonated polyester. A preferred method of including colorants is to use colorants with thermally stable organic coloring compounds having reactive groups, such that the colorants copolymerize and are introduced into the sulfonated polyester to improve its hue. For example, colorants such as dyes having reactive hydroxyl and / or carboxyl groups, including but not limited to blue and red substituted anthraquinones, may copolymerize into the polymer chain. When dyes are used as colorants, they can be added to the copolyester reaction process after transesterification or direct esterification.

[0104] Monofilament fibers typically have a denier of about 15 to about 8000 (abbreviated herein as "d / f"). Fibers comprising the sulfonated polyesters of the present invention will typically have a d / f value of about 40 to about 5000. Monofilaments can be in the form of single-component or multi-component fibers. The multifilament fibers of the present invention will preferably have the following dimensions: from about 1.5 micrometers for meltblown fabrics, from about 0.5 to about 50 d / f for short fibers, and up to about 5000 d / f for monofilament fibers. Multifilament fibers can also be used as crimped or uncrimped yarns and tows. Fibers used in meltblown fabrics and meltblown textiles can be produced in microdenier sizes. The term "microdenier," as used herein, is intended to mean a d / f value of 1 d / f or less. For example, the microdenier fibers of the present invention generally have a d / f value of 1 or less, 0.5 or less, or 0.1 or less. Nanofibers can also be produced by electrospinning.

[0105] As mentioned above, sulfonated polyesters are also advantageous for preparing bicomponent and multicomponent fibers with shaped cross sections.

[0106] In one embodiment, a multicomponent fiber having a shaped cross section is provided. The multicomponent fiber comprises: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) residues of at least 10 molar percentages of at least one sulfonyl monomer, and (iii) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0107] In another embodiment, a multicomponent fiber having a shaped cross section is provided. The multicomponent fiber comprises: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) residues of at least 10 molar percentages of at least one sulfonyl monomer, (iii) residues of two or more diols, (iv) residues of 1,4-cyclohexanediethanol, and (iv) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0108] In another embodiment, a multicomponent fiber having a shaped cross section is provided. The multicomponent fiber comprises: (a) a water-dispersible sulfonyl polyester comprising: (i) residues of isophthalic acid, (ii) residues of terephthalic acid, (iii) residues of at least one sulfonyl monomer, (iv) residues of 1,4-cyclohexanediethanol; and (v) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (b) one or more domains comprising one or more non-water-dispersible polymers immiscible with the sulfonyl polyester.

[0109] Dicarboxylic acid, diol, sulfonated polyester, sulfonated monomer, and branched monomer residues are as described in other embodiments of the present invention above.

[0110] In another embodiment of the invention, the water-dispersible sulfopolyester component of the multicomponent fibers exhibits properties that allow at least one of the following: (A) the multicomponent fibers are spun to a desired low denier; (B) the multicomponent fibers prevent melting or sticking; (C) the sulfopolyester is dispersed at a temperature less than or equal to 90°C to form a dispersion of at least 5 wt% sulfopolyester; (D) the sulfopolyester in these multicomponent fibers is resistant to removal during the hydraulic entanglement of the web formed by the fibers, but is effectively removed at elevated temperatures after hydraulic entanglement; and (E) the multicomponent fibers are heat-set to produce stable, strong fabrics.

[0111] The non-aqueous dispersible component of the multicomponent fiber may include any of the non-aqueous dispersible polymers described herein. Spinning of the fiber may also be carried out according to any of the methods described herein. However, the improved rheological properties of the multicomponent fiber according to this aspect of the invention provide increased stretching speeds. When the sulfonyl polyester and non-aqueous dispersible polymer are extruded to produce the multicomponent extrudate, the multicomponent extrudate can be melt-stretched to produce the multicomponent fiber using any of the methods disclosed herein at a speed of at least about 2000 m / min, more preferably at least about 3000 m / min, more preferably at least about 4000 m / min, and most preferably at least about 4500 m / min. While not intended to be bound by theoretical doctrine, melt-stretching the multicomponent extrudate at these speeds results in at least some degree of oriented crystallinity in the non-aqueous dispersible component of the multicomponent fiber. This oriented crystallinity can improve the dimensional stability of the nonwoven material made from the multicomponent fiber during the next process.

[0112] Another advantage of multicomponent extruders is that they can be melt-stretched into multicomponent fibers with an initial spun denier of less than 6 denier monofilaments. Other ranges of multicomponent fiber sizes include initial spun deniers of less than 4 denier monofilaments and less than 2.5 denier monofilaments.

[0113] Multicomponent fibers comprise multiple segments or domains of one or more non-aqueous dispersible polymers immiscible with sulfonyl polyesters, wherein the segments or domains are substantially isolated from each other by sulfonyl polyesters interposed between them. As used herein, the term "substantially separated" is intended to mean that the segments or domains are separated from each other to allow the segmental sulfonyl polyester domains to form individual fibers upon removal of the sulfonyl polyester. For example, the segments or domains may be in contact with each other, for instance, in a segmented pie configuration, but may be separated by impact or upon removal of the sulfonyl polyester.

[0114] In the multicomponent fibers of the present invention, the weight ratio of sulfonated polyester to the non-aqueous dispersible polymer component is typically from about 60:40 to about 2:98, or, in another example, from about 50:50 to about 5:95. Typically, the sulfonated polyester accounts for 50% by weight or less of the total weight of the multicomponent fiber.

[0115] Segments or domains of a multicomponent fiber may include one or more non-aqueous polymers. Examples of non-aqueous polymers that can be used in segments of a multicomponent fiber include, but are not limited to, polyolefins, polyesters, polyamides, polylactic acid, polycaprolactone, polycarbonate, polyurethane, cellulose esters, and polyvinyl chloride. For example, the non-aqueous polymer may be polyesters such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexanediol, polycyclohexanediol terephthalate, and poly(trimethylene) terephthalate. In another example, the non-aqueous polymer may be biodegradable, as determined according to DIN Standard 54900, and / or biodegradable, as determined according to ASTM standard method D6340-98. Examples of biodegradable polyesters and polyester blends are disclosed in U.S. Patent Nos. 5,599,858; 5,580,911; 5,446,079; and 5,559,171. As used herein, the term "biodegradable" in relation to the non-aqueous dispersible polymers of this invention should be understood to mean that the polymer degrades under environmental influences, such as in a composting environment, over a suitable and apparent time span, for example, as defined by ASTM standard method D6340-98 entitled "Standard Test Methods for Determining Aerobic Biodegradation of Radiolabeled Plastic Materials in an Aqueous or Compost Environment". The non-aqueous dispersible polymers of this invention can also be "biodegradable," meaning that the polymer readily fragments in a composting environment, for example, as defined by DIN Standard 54900. For example, biodegradable polymers initially decrease in molecular weight in the environment under the influence of heat, water, air, microorganisms, and other factors. This decrease in molecular weight leads to a loss of physical properties (toughness) and often results in fiber breakage. Once the molecular weight of the polymer is sufficiently low, the monomers and oligomers are then assimilated by microorganisms. In an oxygen-containing environment, these monomers or oligomers are eventually oxidized to CO2, H2O, and new cellular biomass. In an anaerobic environment, the monomers or oligomers are eventually converted into CO2, H2, acetates (esters), methane, and cellular biomass.

[0116] For example, the non-aqueous dispersible polymer can be an aliphatic-aromatic polyester, abbreviated herein as "AAPE". As used herein, the term "aliphatic-aromatic polyester" refers to a polyester comprising a mixture of residues from aliphatic or cycloaliphatic dicarboxylic acids or diols and aromatic dicarboxylic acids or diols. As used herein, the term "non-aromatic" refers to a monomer whose carboxyl or hydroxyl group is not linked by an aromatic ring, relative to the dicarboxylic acid and diol monomers of the present invention. For example, adipic acid does not contain an aromatic ring in its backbone (i.e., the carbon chain linking the carboxylic acid group) and is therefore "non-aromatic". In contrast, the term "aromatic" refers to a dicarboxylic acid or diol containing an aromatic ring in its backbone, such as terephthalic acid or 2,6-naphthalenedicarboxylic acid. Therefore, "non-aromatic" is intended to include aliphatic and cycloaliphatic structures, such as diols and dicarboxylic acids, which comprise a straight-chain, branched, or cyclic structure as the main chain of constituent carbon atoms, which may be saturated or alkanes, unsaturated (i.e., containing non-aromatic carbon-carbon double bonds), or alkynes (i.e., containing carbon-carbon triple bonds). Thus, within the scope of the specification and claims of this invention, "non-aromatic" is intended to include straight-chain and branched chain structures (referred to herein as "aliphatic") and cyclic structures (referred herein as "alicyclic" or "cycloaliphatic"). The term "non-aromatic," however, is not intended to exclude any aromatic substituents that may be attached to the main chain of an aliphatic or cycloaliphatic diol or dicarboxylic acid. In this invention, the difunctional carboxylic acid is generally an aliphatic dicarboxylic acid, such as adipic acid, or an aromatic dicarboxylic acid, such as terephthalic acid. Bifunctional hydroxyl compounds can be cyclic aliphatic diols, such as 1,4-cyclohexanediol, linear or branched aliphatic diols, such as 1,4-butanediol, or aromatic diols, such as hydroquinone.

[0117] AAPE can be a linear or branched random copolyester and / or a chain-extended copolyester comprising diol residues, said diol residues comprising one or more substituted or unsubstituted, linear or branched diol residues, said diols being selected from aliphatic diols containing 2 to 8 carbon atoms, polyalkylene ether diols containing 2 to 8 carbon atoms, and cyclic aliphatic diols containing about 4 to 12 carbon atoms. The substituted diols will generally comprise 1 to 4 substituents, independently selected from halogens, C6-C... 10Aryl and C1-C4 alkoxy groups. Examples of diols that may be used include, but are not limited to, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, polyethylene glycol, diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,3-cyclohexanediethanol, 1,4-cyclohexanediethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol, and tetraethylene glycol. Preferred diols include one or more selected from 1,4-butanediol; 1,3-propanediol; ethylene glycol; 1,6-hexanediol; diethylene glycol; or 1,4-cyclohexanediethanol. AAPE also includes diacid residues comprising about 35 to about 99 mol%, based on the total molar number of diacid residues, one or more substituted or unsubstituted, linear or branched non-aromatic dicarboxylic acid residues, said dicarboxylic acid being selected from aliphatic dicarboxylic acids comprising 2 to about 12 carbon atoms and cyclic aliphatic acids comprising about 5 to about 10 carbon atoms. The substituted non-aromatic dicarboxylic acids generally contain 1 to about 4 substituents selected from halogens, C6-C... 10 Aryl and C1-C4 alkoxy groups. Non-limiting examples of non-aromatic diacids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaric acid, octanoic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, dihydroxyacetic acid, itaconic acid, maleic acid, and 2,5-norbornenedicarboxylic acid. In addition to non-aromatic dicarboxylic acids, AAPE comprises about 1 to about 65 mol%, based on the total molar number of diacid residues, one or more substituted or unsubstituted aromatic dicarboxylic acid residues containing 6 to about 10 carbon atoms. In cases where substituted aromatic dicarboxylic acids are used, they will generally contain 1 to about 4 substituents selected from halogens, C6-C4 alkoxy groups, and C4-C4 alkoxy groups. 10 Aryl and C1-C4 alkoxy groups. Non-limiting examples of aromatic dicarboxylic acids that can be used in the AAPE of our invention include salts of terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid, and 2,6-naphthalenedicarboxylic acid. More preferably, non-aromatic dicarboxylic acids will include adipic acid, aromatic dicarboxylic acids will include terephthalic acid, and diols will include 1,4-butanediol.

[0118] Other feasible compositions of the AAPE for our invention are those prepared from the following diols and dicarboxylic acids (or their polyester equivalents, such as diesters), in the following molar percentages based on 100 mol% of the diacid component and 100 mol% of the diol component: (1) glutaric acid (about 30 to about 75%); terephthalic acid (about 25 to about 70%); 1,4-butanediol (about 90 to 100%); and modified... (1) Diol (0 to about 10%); (2) Succinic acid (about 30 to about 95%); terephthalic acid (about 5 to about 70%); 1,4-Butanediol (about 90 to 100%); and modified diol (0 to about 10%); and (3) Adipic acid (about 30 to about 75%); terephthalic acid (about 25 to about 70%); 1,4-Butanediol (about 90 to 100%); and modified diol (0 to about 10%).

[0119] The modified diol is preferably selected from 1,4-cyclohexanediol, triethylene glycol, polyethylene glycol, and neopentyl glycol. The most preferred AAPE is a linear, branched, or extended copolyester comprising about 50 to about 60 mol% adipic acid residues, about 40 to about 50 mol% terephthalic acid residues, and at least 95 mol% 1,4-butanediol residues. Even more preferably, the adipic acid residues comprise about 55 to about 60 mol%, the terephthalic acid residues comprise about 40 to about 45 mol%, and the diol residues comprise about 95 mol% 1,4-butanediol residues. This composition is commercially available under the trademark EASTAR. Copolyesters were sourced from Eastman Chemical Company, Kingsport, TN, and trademarks. Obtained from BASF Corporation.

[0120] Additionally, specific examples of preferred AAPEs include poly(tetramethylene glutarate-co-terephthalate) comprising (a) 50 mol% glutaric acid residues, 50 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues; (b) 60 mol% glutaric acid residues, 40 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues; or (c) 40 mol% glutaric acid residues, 60 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues; and poly(tetramethylene succinate-co-terephthalate) comprising (a) 85 mol% succinic acid residues, 15 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues. The following are listed: (a) 70 mol% 1,4-butanediol residues, (b) 70 mol% succinic acid residues, 30 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues; and (b) poly(ethylene succinate-co-terephthalate) comprising 70 mol% succinic acid residues, 30 mol% terephthalic acid residues, and 100 mol% ethylene glycol residues; and poly(tetramethylene adipate-co-terephthalate) comprising (a) 85 mol% adipic acid residues, 15 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues; or (b) 55 mol% adipic acid residues, 45 mol% terephthalic acid residues, and 100 mol% 1,4-butanediol residues.

[0121] AAPE preferably comprises about 10 to about 1,000 repeating units, more preferably about 15 to about 600 repeating units. The concentrated logarithmic viscosity of AAPE can be about 0.4 to about 2.0 dL / g, or more preferably about 0.7 to about 1.6 dL / g, as measured at 25°C using a copolyester of the following concentration: 0.5 g copolyester / 100 ml phenol / tetrachloroethane (60 / 40, by weight) solution.

[0122] Optionally, the AAPE may contain residues of a branching agent. The molar percentage of the branching agent ranges from about 0 to about 2 mol%, preferably from about 0.1 to about 1 mol%, and most preferably from about 0.1 to about 0.5 mol%, based on the total molar number of diacid or diol residues (depending on whether the branching agent contains carboxyl or hydroxyl groups). The branching agent preferably has the following weight-average molecular weight: from about 50 to about 5000, more preferably from about 92 to about 3000, and a functionality of about 3 to about 6. The branching agent may, for example, be a polyol having 3 to 6 hydroxyl groups, a polycarboxylic acid (or ester equivalent group) having 3 or 4 carboxyl groups, or an esterified residue of a hydroxy acid having a total of 3 to 6 hydroxyl and carboxyl groups. Additionally, the AAPE may be branched by adding a peroxide during reactive extrusion.

[0123] The segments of the non-aqueous dispersible polymer can differ in fineness from others and can be arranged into any geometry of forming or processing cross-section known to those skilled in the art. For example, sulfonyl polyesters and non-aqueous dispersible polymers can be used to prepare bicomponent fibers having processing geometries such as side-by-side, "island-type," fan-shaped, sheath / core-type, strip-shaped, or other configurations known to those skilled in the art. Other multicomponent configurations are also possible. Subsequently removing one side of the side-by-side type, a portion of the "sea" or "cake" of the island-type can yield very fine fibers. Methods for preparing bicomponent fibers are also well known to those skilled in the art. In the bicomponent fibers, the content of the sulfonyl polyester fiber of the present invention can be from about 10 to about 90% by weight and will generally be used for the sheath portion of the sheath / core fiber. Generally, when using water-insoluble or non-aqueous dispersible polymers, the resulting bicomponent or multicomponent fibers are not completely water-dispersible. Side-by-side combinations with significant differences in heat shrinkage can be used to form helical crimps. If crimping is desired, serrated or box-stuff crimps are generally suitable for many applications. If the second polymer component is located in the core of the skin / core configuration, the core can optionally be stabilized.

[0124] Sulfonated polyesters are particularly suitable for fibers with “island-type” or “fan-shaped” cross-sections because they require only neutral or slightly acidic (i.e., “soft”) water for dispersion, as opposed to solutions containing caustic alkalis, which are sometimes required to remove other water-dispersible polymers from multi-component fibers. The term “soft water” as used in this disclosure refers to water having a maximum of 5 grains / gallon of CaCO3 (1 grain / gallon of CaCO3 is equivalent to 17.1 ppm).

[0125] In one embodiment, the multicomponent fiber has an island-shaped or fan-shaped cross section and contains less than 10% by weight of pigment or filler, based on the total weight of the fiber.

[0126] Methods for manufacturing multi-component fibers

[0127] Our novel multicomponent fibers can be prepared by any method known to those skilled in the art. In one embodiment, a method for producing at least one multicomponent fiber is provided. The method comprises spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into a multicomponent fiber, the sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all of the stated molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages.

[0128] In another embodiment of the invention, a method for producing at least one multicomponent fiber having a shaped cross section is provided. The method includes spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into a multicomponent fiber, the sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises a molar ratio of diethylene glycol residues to 1,4-cyclohexanediethanol residues of less than 1:1, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages.

[0129] In another embodiment of the invention, a method for producing at least one multicomponent fiber having a shaped cross section is provided. The method comprises spinning at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the sulfonyl polyester into a multicomponent fiber, the sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 mol percent) and hydroxyl repetitive units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 mol percent.

[0130] The multicomponent fiber has multiple segments comprising a non-aqueous polymer, and these segments are substantially isolated from each other by sulfonyl polyesters interposed between them. In one embodiment, the fiber contains less than 10% by weight of pigment or filler, based on the total weight of the fiber. For example, the multicomponent fiber can be prepared by melting sulfonyl polyester and one or more non-aqueous polymers in a separate extruder and introducing separate polymer flows into a spinneret or extrusion die having multiple distributed flow paths, such that the non-aqueous polymer components form small segments or fine strands, which are substantially isolated from each other by sulfonyl polyesters interposed therebetween. The cross-section of such a fiber can be, for example, a fan-shaped structure or an island-shaped structure. In another example, sulfonyl polyester and one or more non-aqueous polymers are separately supplied to a spinneret orifice and subsequently extruded in a core-sheath configuration, wherein the non-aqueous polymer forms the “core,” which is substantially surrounded by a sulfonyl polyester “sheath” polymer. In the case of such concentric fibers, the orifice supplying the "core" polymer is located at the center of the spinning orifice outlet, and the flow conditions of the core polymer fluid are strictly controlled to maintain the concentricity of the two components during spinning. Variations in the spinneret orifice allow for different core and / or sheath shapes to be obtained within the fiber cross-section. In yet another example, multicomponent fibers with a side-by-side cross-section or configuration can be produced by (1) co-extruding water-dispersible sulfonyl polyester and non-water-dispersible polymer separately through orifices and combining the individual polymer streams at substantially the same rate to form a combined stream below the spinneret surface; or (2) feeding the two polymer streams separately at substantially the same rate through orifices that converge at the spinneret surface, thereby combining them into a combined stream at the spinneret surface. In both cases, the velocity of each polymer stream at the merging point is determined by its metering pump speed, the number of orifices, and the orifice size.

[0131] Typically, upon exiting the spinneret, the fibers are rapidly cooled by cross-flowing air, thus solidifying them. During this step, various finishes and sizing agents can be applied to the fibers. The cooled fibers are then typically stretched and wound onto a take-up beam. Other additives can be added to the finishes in effective amounts, such as emulsifiers, antistatic agents, antimicrobial agents, defoamers, lubricants, heat stabilizers, and UV stabilizers.

[0132] Optionally, the stretched fibers can be deformed and wound to form a fluffy, continuous filament. This one-step technique is known in the art and is called spinning-stretching-texturing. Other embodiments include flat filament (undeformed) yarns, or short, chopped fibers, crimped or uncrimped.

[0133] End uses of multi-component fibers

[0134] The multicomponent fibers of this invention can be used in any end-use application known in the art. In one embodiment of the invention, the multicomponent fibers are used to produce yarn. Yarn is defined as a continuous bundle of fibers suitable for weaving, knitting, fusing, or otherwise interlacing to produce textiles, such as fabrics. In one embodiment of the invention, the multicomponent fibers are filament yarns. Filament yarns are first stretched into fibers of continuous length and may be twisted during post-processing. In another embodiment of the invention, the multicomponent fibers are cut into short fiber lengths and then twisted into continuous strands referred to as staple yarns.

[0135] In another embodiment of the invention, the multi-component fiber can be combined with at least one other fiber to produce a yarn. The yarn can be a staple fiber yarn or a filament yarn. Other fibers may include, but are not limited to, cotton, flax, silk, sisal / grass, leather, acetate, acrylic acid, modified polyacrylonitrile, polylactic acid, salon, cellulose fiber pulp, inorganic fibers (e.g., glass, carbon, boron, ceramics, and combinations thereof), polyester fibers, nylon fibers, polyolefin fibers, rayon fibers, lyocell fibers, cellulose ester fibers, post-consumer recycled fibers, elastomer fibers, and combinations thereof.

[0136] Alternatively, multi-component fibers can be post-processed using various techniques, such as stretching or texturing. Stretched fibers can be textured and wound to form loose, continuous filaments. A one-step technique known in the art is called spinning-stretching-texturing. Other embodiments include flat filament (untextured) yarns, or chopped short fibers, crimped or uncrimped.

[0137] As used herein, texturing refers to the treatment of flat filaments (or fibers) such that they are deformed along their length into loops, helices, crimps, or other deformations (i.e., "texture"). Texturized filaments or fibers increase their bulk, porosity, elasticity, and / or softness. Different amounts (or degrees) of texturing can provide filaments and fibers with different properties. Texturing and texturizing are used interchangeably herein.

[0138] The filaments and fibers are then used to manufacture yarns. The filaments or fibers can be combined with other filaments or fibers to prepare yarns, and more than one type of yarn can be combined together by methods known to those skilled in the art, such as deformation, winding, etc., to prepare new yarns.

[0139] Stretched filaments or fibers can be deformed to increase fiber crimp or deformation and bulkiness, depending on the desired properties, using methods such as friction disc stretching (also known as false twisting), air jet stretching, knife edge crimping, packing box stretching, and stretch winding.

[0140] The multi-component fibers of this invention can be used to produce any articles known in the art. Articles according to the invention include, but are not limited to, nonwoven fabrics, knitted fabrics, woven fabrics, braided fabrics, and combinations thereof. Synthetic fabrics, such as artificial suede and leather, comprising the multi-component fibers of this invention can also be produced.

[0141] The woven fabrics according to the present invention can be manufactured from the multi-component fibers of the present invention using different techniques. These methods include, but are not limited to, weaving, knitting, and braiding processes.

[0142] During the weaving process, two sets of yarns, namely warp and weft, interweave to form the woven fabric of this invention. The way the two sets of yarns interweave determines the weave structure. The weaving process can be achieved using different equipment, including but not limited to dobby looms, jacquard looms, and power looms. By using various combinations of the five basic weaves, namely plain weave, twill weave, satin weave, jacquard, and pile, an almost infinite variety of structures can be produced.

[0143] In the knitting process, the fabric of the present invention is formed by a series of loops or by interlocking one or more yarns. Two main types of knitting include, but are not limited to, warp knitting and weft knitting.

[0144] Warp knitting is a type of knitting in which the yarn typically extends longitudinally within the fabric. The yarn is formed into warp yarns on a warp beam, with one or more yarns used per needle. Weft knitting, however, is a common type of knitting in which a continuous yarn extends crosswise within the fabric, thus forming all the loops in a single row. Weft knitting types include circular and flat knitting.

[0145] Weaving is a method of producing fabric in which interlacing occurs at angles other than 90 degrees. Weaving is the interlacing or winding of three or more individual strands of one or more materials in a diagonally overlapping pattern. Compared to a weaving process that typically involves two separate sets of perpendicular strands (warp and weft), woven fabrics are usually long and narrow, where each component strand functions identically as it bends forward through overlapping clumps of other strands, resulting in non-perpendicular crossing angles.

[0146] Woven, knitted, braided, or combined fabrics can be used in any article known in the art. Woven, knitted, or braided articles can be used in any type of clothing, footwear, home décor items, military applications, and technical applications. Apparel can include sports and outdoor clothing, industrial clothing, and everyday clothing. Examples of sports and outdoor clothing include, but are not limited to, base layers, jackets and vests, woven sports and fishing shirts, trousers and shorts, socks, accessories, swimwear and mid-layers, sweaters, and sweatshirts. Examples of industrial clothing include military training clothing, cleanroom clothing, personal protective equipment, medical drapes and gowns, industrial uniforms, and prescription compression orthotics. Examples of everyday clothing include, but are not limited to, undergarments, jackets and vests, suits, women's wear, oxford and cardigan woven shirts, skirts, tops, shirts, leggings, tights, trousers, shorts, and jeans. Footwear includes, but is not limited to, sandals, boots, hiking boots, running shoes, ski boots and snow boots, other athletic and outdoor footwear, tennis shoes, business shoes, work boots, other everyday shoes, and athletic / casual shoes. Examples of home décor products include, but are not limited to, accessories, awnings, bath products, bedspreads, sheets and quilts, blankets and shawls, wide-width carpets, carpet backings, curtains, drapes, fiber-filled mats, kitchen linens, lampshades, linings, mattress padding, mattress covers, oriental and designer carpets, outdoor / indoor carpets, paving materials (edging), scattered and reinforced carpets, coverings, tablecloths and linens, upholstery, tapestries, wall hangings, cleaning cloths, and woven mats and plazas. Technical applications include, but are not limited to, barrier fabrics, geotextiles, and automotive fabrics. Examples of barrier fabrics include, but are not limited to, cleanroom fabrics, filters, flags and banners, packaging, and tapes. Automotive fabrics include, but are not limited to, automotive interior trim, airbags, and other automotive fabrics. Geotextiles include permeable fabrics that, when used in conjunction with soil, have the ability to separate, filter, reinforce, protect, or drain.

[0147] The nonwoven fabrics according to the present invention can be manufactured by various techniques. These methods include, but are not limited to, meltblown, spunbond, carding, air-blown, hot calendering, adhesive bonding, hot air bonding, needle punching, hydroentanglement, electrospinning, and combinations thereof.

[0148] In the meltblown process, the nonwoven fabric of the present invention is formed by the following steps: extruding a molten water-dispersible polymer and a non-water-dispersible polymer other than any other polymer known in the art through a die, and then drawing and / or optionally breaking the resulting filaments with hot, high-speed air or airflow to form short or long fiber segments collected on a moving screen, which bond together at the moving screen during cooling.

[0149] In alternative processes, the meltblown process typically includes the following steps: (a) extruding strands from a spinneret; (b) simultaneously quenching and refining the polymer agglomerates directly below the spinneret using a high-speed hot air stream; and (c) collecting the stretched strands into a web on a porous surface. Meltblown webs can be bonded in various ways, including but not limited to self-bonding (i.e., self-bonding without further processing), thermocalendering, adhesive bonding, hot air bonding, needle punching, hydraulic entanglement, and combinations thereof.

[0150] In spunbond fabrication, the manufacture of nonwoven fabrics includes the following steps: (a) extruding strands of a water-dispersible polymer and a non-water-dispersible polymer, other than any other polymer known in the art, from a spinneret; (b) quenching the strands with an airflow, typically cooling the airflow to accelerate the solidification of the molten strands; (c) thinning the filaments by advancing them through a quenching zone under tensile tension, which can be applied by pneumatically encasing the filaments in the airflow or by winding them around mechanical stretching rollers of a type commonly used in the textile fiber industry; (d) collecting the stretched strands into a web on a porous surface, such as a moving screen or a porous belt; and (e) bonding the web of loose strands into a nonwoven fabric. Bonding can be achieved by various methods, including but not limited to thermocalendering, adhesive bonding, hot air bonding, needle punching, hydroentanglement, and combinations thereof.

[0151] The multi-component fibers of this invention can be used to produce a variety of nonwoven products, including filter media (e.g., HEPA filters, ULPA filters, coalescing filters, liquid filters, desalination filters, automotive filters, coffee filters, tea bags, and vacuum dust collection bags), battery separators, personal hygiene products, sanitary napkins, tampons, diapers, disposable wipes (e.g., car wipes, baby wipes, hand and body wipes, floor cleaning wipes, face wipes, toddler wipes, dusting and polishing wipes, and nail polish remover wipes), flexible packaging (e.g., envelopes, food packaging, multi-layer bags, and finally sterilized medical packaging), geotextiles (e.g., weed barriers, irrigation barriers, corrosion barriers, and seed support media), building and structural materials (e.g., outer... The nonwoven fabric includes envelopes, moisture-proof films, gypsum board, wallpaper, paper, bitumen, paper, underlayment and decorative materials, surgical and medical materials (e.g., surgical drapes and gowns, bone support media, and tissue support media), security paper (e.g., paper, banknotes, banknotes and lottery checks, personal lottery tickets, and lottery record paper), flexible cardboard, flexible synthetic materials, flexible cardboard and flexible materials, slot insulation materials, capacitor paper and lampshades), catalytic support membranes, thermal insulation materials, labels, food packaging materials (e.g., sterile liquid packaging boards, tobacco, release paper, pouches and bags, grease-resistant, heat-resistant boards, cup holders, food packaging and coated surfaces), and printing and publishing paper (e.g., water-resistant and tear-resistant printing paper, business books, banners, maps and charts, opaque materials and carbonless materials). In one embodiment, the nonwoven fabric is selected from battery separators, high-efficiency filters and high-strength paper.

[0152] Other nonwoven articles and methods of producing such nonwoven articles are disclosed in U.S. Patent No. 6,989,193, U.S. Patent Application Publication No. 2005 / 0282008, U.S. Patent Application Publication No. 2006 / 0194047, U.S. Patent No. 7,687,143, U.S. Patent Application Publication No. 2008 / 0311815, and U.S. Patent Application Publication No. 2008 / 0160859, the disclosures of which are incorporated herein by reference.

[0153] The adhesive dispersion can be applied to the nonwoven article by any method known in the art. In one embodiment, the adhesive dispersion is applied to the nonwoven article as an aqueous dispersion by spraying or rolling it onto the nonwoven article. After application of the adhesive dispersion, the nonwoven article and the adhesive dispersion can be subjected to a drying step to allow the adhesive to solidify.

[0154] The adhesive dispersion may comprise synthetic resin adhesives and / or phenolic resin adhesives. Synthetic resin adhesives are selected from acrylic copolymers, styrene copolymers, styrene-butadiene copolymers, vinyl copolymers, polyurethanes, sulfonated polyesters, and combinations thereof. In one embodiment, the adhesive may comprise blends of different sulfonated polyesters with varying sulfonated monomer contents. For example, at least one sulfonated polyester comprises at least 15 mol% of sulfonated monomers and at least 45 mol% of CHDM (considering the first spelling) and / or at least one sulfonated polyester comprises less than 10 mol% of sulfonated monomers and at least 70 mol% of CHDM. The amount of sulfonated monomers present in the sulfonated polyester significantly affects its water permeability. In another embodiment, the adhesive may consist of a sulfonated polyester blend comprising at least one hydrophilic sulfonated polyester and at least one hydrophobic sulfonated polyester. An example of a hydrophilic sulfonated polyester that can be used as an adhesive is Eastek from EASTMAN Corporation. Similarly, examples of hydrophobic sulfonated polyesters used as adhesives include Eastek from EASTMAN. These two sulfonated polyesters can be blended accordingly to optimize the water permeability of the adhesive. Depending on the desired end use of the nonwoven fabric, the adhesive can be hydrophilic or hydrophobic.

[0155] Undissolved or dried sulfonated polyesters are known to form strong adhesive bonds with a variety of substrates, including but not limited to fluff pulp, cotton, acrylic resins, rayon, lyocell, PLA (polylactic acid), cellulose acetate, cellulose acetate propionate, polyethylene terephthalate, polybutylene terephthalate, poly(trimethylene) terephthalate, polycyclohexane terephthalate, copolyesters, polyamides (e.g., nylon), stainless steel, aluminum, treated polyolefins, PAN (polyacrylonitrile), and polycarbonate. Therefore, sulfonated polyesters serve as excellent adhesives for nonwovens. Consequently, our novel nonwovens can possess a variety of functionalities when using sulfonated polyester adhesives.

[0156] Nonwoven articles may also include coatings. The coating may be applied to the nonwoven article after it and an optional adhesive dispersion have been dried. The coating may include decorative coatings, printing inks, barrier coatings, adhesive coatings, or heat-sealing coatings. In another example, the coating may include a liquid barrier and / or a microbial barrier.

[0157] After the production of the nonwoven article, optional adhesives are added, and / or optional coatings are added, the nonwoven article may undergo a heat-setting step, which includes heating the nonwoven article to a temperature of at least 100°C, and more preferably to at least about 120°C. The heat-setting step releases internal fiber stress and helps produce dimensionally stable fabric products. Preferably, when the heat-set material is reheated to the temperature it was heated to during the heat-setting step, it exhibits a surface area shrinkage of less than about 10%, 5%, or 1% of its initial surface area. However, if the nonwoven article undergoes heat setting, it may not be resizingable and / or recyclable by resizing the nonwoven article after use.

[0158] As used herein, the term “repulpable” refers to any nonwoven fabric that, without heat setting, disintegrates at 3,000 rpm and 1.2% consistency after 5,000, 10,000, or 15,000 rotations according to the TAPPI standard.

[0159] In another aspect of the invention, the nonwoven article may further comprise at least one or more additional fibers. These additional fibers may have a different composition and / or configuration (e.g., length, minimum transverse dimension, maximum transverse dimension, cross-sectional shape, or combinations thereof) from the strip fibers, and may be any type of fiber known in the art, depending on the type of nonwoven article to be produced. In one embodiment of the invention, the additional fibers may be selected from cellulose fiber pulp, inorganic fibers (e.g., glass, carbon, boron, ceramics, and combinations thereof), polyester fibers, nylon fibers, polyolefin fibers, rayon fibers, lyocell fibers, cellulose ester fibers, post-consumer recycled fibers, and combinations thereof. The nonwoven article may comprise at least 10, 15, 20, 25, 30, 40, or 60% by weight of the nonwoven article and / or no more than 99, 98, 95, 90, 85, 80, 70, 60, or 50% by weight of the additional fibers. In one embodiment, the additional fiber is a cellulose fiber constituting at least 10, 25, or 40% by weight and / or no more than 80, 70, 60, or 50% by weight of the nonwoven article. The cellulose fiber may include hardwood pulp fiber, softwood pulp fiber, and / or regenerated cellulose fiber. In another embodiment, at least one additional fiber is a glass fiber with a minimum transverse dimension of less than 30, 25, 10, 8, 6, 4, 2, or 1 micrometer.

[0160] Nonwoven products may also contain one or more additives. Additives may be added to the wet slurry sheet before wet or dry web forming of the non-aqueous dispersible microfibers. Additives include, but are not limited to, starch, fillers, light and heat stabilizers, antistatic agents, extrusion aids, dyes, anti-counterfeiting markers, slip agents, toughening agents, adhesion promoters, oxidation stabilizers, UV absorbers, colorants, pigments, opacifiers (matting agents), optical brighteners, fillers, nucleating agents, plasticizers, viscosity modifiers, surface modifiers, antimicrobial agents, defoamers, lubricants, heat stabilizers, emulsifiers, disinfectants, cold flow inhibitors, branching agents, oils, waxes, and catalysts. Nonwoven products may contain at least 0.05, 0.1, or 0.5% by weight and / or no more than 10, 5, or 2% by weight of one or more additives.

[0161] Generally, the manufacturing methods for producing nonwoven products from multi-component fibers can be divided into the following groups: dry web forming, wet web forming, combinations of these methods, or other nonwoven methods.

[0162] Dry-laid nonwovens are typically manufactured using short-fiber processing machinery designed to manipulate fibers in a dry state. These methods include mechanical methods such as carding, aerodynamics, and other airflow-based web-forming methods. This category also includes nonwovens made from filaments in the form of tows, and fabrics composed of short fibers and sewn filaments or yarns (presumably carding machines?), i.e., stitch-bonded nonwovens. Carding is the process of untangling, cleaning, and blending fibers to prepare a web for further processing into nonwovens. This method primarily involves arranging fibers together, binding them together through mechanical entanglement and fiber-fiber friction to form a web. Carding machines (e.g., roller carding machines) are typically configured with one or more master cylinders, rollers or stationary tops, one or more doffing machines, or various combinations of these main components. Carding involves combing or processing non-aqueous microfibers between carding points on a series of cooperating carding rollers. Types of carding machines include roller carding machines, carding machines, cotton carding machines, and random carding machines. Garnett machines can also be used to arrange these fibers.

[0163] Multicomponent fibers used in dry web forming processes can also be arranged via airflow web forming. These fibers are guided by airflow onto a collector, which can be a flat conveyor or a roller.

[0164] Wet web forming processes involve using papermaking techniques to produce nonwoven articles. These nonwoven articles are manufactured using machines associated with pulp fiberization (e.g., hammer mills) and paper forming (e.g., pumping pulp onto continuous screens designed to manipulate short fibers in a fluid).

[0165] In one embodiment of the wet web forming process, multi-component fibers are suspended in water and carried to a forming unit, where water is discharged through a forming screen and fibers are deposited on the screen wires.

[0166] In another embodiment of the wet web forming process, multi-component fibers are dehydrated at high speeds of up to 1,500 m / min on a screen or wire mesh rotating at the start of a hydroforming machine in a dehydration module (e.g., absorbent box, foil, and curing agent). The sheet is dehydrated to approximately 20 to 30% solids content. The sheet can then be pressed and dried.

[0167] Nonwoven articles are bonded together by: 1) mechanical fiber cohesion and interlocking in a web or matte fabric; 2) various techniques of fiber fusion bonding, including the use of bonding fibers and / or the utilization of the thermoplastic properties of certain polymers and polymer blends; 3) the use of bonding resins such as starch, casein, cellulose derivatives, or synthetic resins such as acrylic copolymer latex, styrene copolymers, vinyl copolymers, polyurethanes, or sulfonated polyesters; 4) the use of powdered adhesives; or 5) combinations thereof. Fibers are typically deposited randomly, but orientation in one direction is possible, followed by bonding / adhesion using one of the methods described above. In one embodiment, the multi-component fibers can be substantially uniformly distributed throughout the nonwoven article.

[0168] Nonwoven products may also include one or more layers of water-dispersible fibers, multi-component fibers or micro denier fibers.

[0169] Nonwoven fabrics may also include various powders and granules to improve their absorbency and their ability to act as delivery carriers for other additives. Examples of powders and granules include, but are not limited to, talc, starch, various absorbents, water-dispersible or water-swellable polymers (e.g., superabsorbent polymers, sulfonated polyesters, and poly(vinyl alcohol)), silica, activated carbon, pigments, and microcapsules. As mentioned above, additives may also be present, but are not essential, as required by a particular application.

[0170] Methods for producing microfibers

[0171] The sulfonyl polyester of the present invention can be subsequently removed from multicomponent fibers by dissolving the water-dispersible sulfonyl polyester segments and leaving smaller filaments or microdenier fibers of the non-water-dispersible polymer. Therefore, the present invention provides a method for microdenier fibers comprising: (A) spinning a water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, and wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar). (i) a percentage) of hydroxyl repeating units (100 molar percentage), and wherein all said molar percentages are based on the sum of all acids and hydroxyl repeating units equaling 200 molar percentages; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl... The sulfonyl polyester comprises substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits at least 5 A glass transition temperature of 7°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; wherein the fiber has a plurality of segments comprising a non-aqueous dispersible polymer, wherein the segments are substantially isolated from each other by sulfonyl polyester interposed between said segments; and (B) contacting the multicomponent fiber with water to remove the sulfonyl polyester, thereby forming microdenier fibers.

[0172] In another embodiment, the multicomponent fiber contains less than 10% by weight of pigment or filler, based on the total weight of the fiber.

[0173] Typically, the multicomponent fibers are contacted with water at a temperature ranging from about 25°C to about 100°C or from about 50°C to about 80°C for a period of about 10 to about 600 seconds, thereby causing the sulfonyl polyester to dissipate or dissolve. After the sulfonyl polyester is removed, the remaining non-aqueous polymer microfibers typically have an average fineness of 1 d / f or less, typically 0.5 d / f or less, or more typically 0.1 d / f or less.

[0174] Typical applications of these remaining non-aqueous dispersible polymer microfibers include nonwoven fabrics such as artificial leather, suede, rags, and filter media. Filter media made from these microfibers can be used to filter air or liquids. Filter media for liquids include, but are not limited to, water, bodily fluids, solvents, and hydrocarbons. The ionic properties of sulfonyl polyesters also result in advantageously poor solubility in saline media such as bodily fluids. These properties are ideal in personal care products and cleaning cloths that can be flushed or otherwise disposed of in domestic sewage systems. Selected sulfonyl polyesters have also been used as dispersants in dye baths and as soil redeposition preventative agents during the washing cycle.

[0175] In one embodiment, the water used to remove sulfonyl polyester from the multi-component fiber is above room temperature. In other embodiments, the water used to remove sulfonyl polyester is at least about 45°C, at least about 60°C, or at least about 80°C.

[0176] Methods for producing short-cut microfibers

[0177] In another embodiment of the invention, a method for producing segmented non-aqueous polymer microfibers is provided. The method comprises: (A) slicing a multicomponent fiber into segmented multicomponent fibers; wherein the multicomponent fiber comprises at least one aqueously dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, and wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (1... (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units. The sulfonyl polyester comprises: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar amounts of acid repeating units (100 mol%) and hydroxyl repeating units (100 mol%). (A) contacting the fiber-containing raw material with water to produce a fiber-mixed slurry; wherein the fiber-containing raw material comprises diced multicomponent fibers; (C) heating the fiber-mixed slurry to produce a heated fiber-mixed slurry; (D) optionally, mixing the fiber-mixed slurry in a shear zone; (E) removing at least a portion of the sulfonated polyester from the multicomponent fibers to produce a slurry mixture comprising a sulfonated polyester dispersion and non-aqueous polymer microfibers; and (F) separating the non-aqueous polymer microfibers from the slurry mixture.

[0178] Multicomponent fibers can be cut to any length suitable for producing nonwoven articles. In one embodiment of the invention, the multicomponent fibers are cut to lengths from about 1 mm to about 50 mm. In other embodiments, the multicomponent fibers can be cut to lengths ranging from about 1 mm to about 25 mm, from about 1 mm to about 20 mm, from about 1 mm to about 15 mm, from about 1 mm to about 10 mm, from about 1 mm to about 6 mm, from about 1 mm to about 5 mm, and from about 1 mm to about 5 mm. In another embodiment, the multicomponent fibers are cut into lengths less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, or less than about 5 mm. In another aspect of the invention, the multicomponent fibers can be cut into a mixture of different lengths.

[0179] As used in this disclosure, the term "staple fiber" is used to define fibers cut to lengths greater than 25 mm to about 50 mm. The term "short-cut fiber" is used to define fibers cut to lengths of about 25 mm or less.

[0180] The fiber-containing raw material may include any other type of fiber that can be used to produce nonwoven articles. In one embodiment, the fiber-containing raw material further comprises at least one fiber selected from cellulose fiber pulp, glass fiber, polyester fiber, nylon fiber, polyolefin fiber, rayon fiber, and cellulose ester fiber.

[0181] The fiber-containing raw material is mixed with water to produce a fiber-mixed slurry. To facilitate the removal of water-dispersible sulfonyl polyester, the water used can be soft water or deionized water. Soft water has been predefined in this disclosure. In one embodiment of the invention, at least one water softener can be used to facilitate the removal of water-dispersible sulfonyl polyester from multi-component fibers. Any water softener known in the art can be used. In one embodiment, the water softener is a chelating agent or a calcium ion masking agent. Suitable chelating agents or calcium ion masking agents are compounds containing multiple carboxylic acid groups per molecule, wherein the carboxylic acid groups in the molecular structure of the chelating agent are separated by 2 to 6 atoms. Tetrasodium ethylenediaminetetraacetate (EDTA) is the most commonly used example of a chelating agent, which contains four carboxylic acid moieties per molecule, with adjacent carboxylic acid groups spaced by 3 atoms. Sodium polyacrylate is an example of a calcium masking agent, containing carboxyl groups separated by two atoms between carboxyl groups. Sodium salts of maleic acid or succinic acid are examples of the most basic chelating agent compounds. Other examples of applicable chelating agents include compounds in which multiple carboxylic acid groups are typically present in the molecular structure, wherein the carboxylic acid groups are separated by a desired distance (2 to 6 atomic units), which produces a favorable steric interaction with divalent or polyvalent cations such as calcium, resulting in the chelating agent preferentially binding to divalent or polyvalent cations. Such compounds include, but are not limited to, diethylenetriaminepentaacetic acid; diethylenetriamine-N,N,N',N',N”-pentaacetic acid; glutaric acid; N,N-bis(2-(bis-(carboxymethyl)amino)ethyl)glycine; diethylenetriaminepentaacetic acid; [[(carboxymethyl)imino]bis(ethylenediamine)]-tetraacetic acid; ethylenediaminetetraacetic acid; ethylenediaminetetraacetic acid; EDTA, free base; EDTA free acid; ethylenediamine-N,N,N',N'-tetraacetic acid; ethylenediaminetetraacetic acid (hampene); velene; N,N'-1,2-ethanediylbis-(N-(carboxymethyl)glycine); ethylenediaminetetraacetic acid; N,N-bis(carboxymethyl)glycine; hypoazolyltriacetic acid; trilone A; α,α',α”-trimethylaminetricarboxylic acid; tri(carboxymethyl)amine; aminotriacetic acid; hampshire NTA acids; hypoazine-2,2',2”-triacetic acid; titriplex i; hypoazine-triacetic acid; and mixtures thereof.

[0182] The required amount of water softener depends on the hardness of the water used, expressed in terms of Ca. ++ And other multivalent ion meters.

[0183] The fiber blending slurry is heated to produce a heated fiber blending slurry. The temperature is sufficient to remove a portion of the sulfonated polyester from the multi-component fibers. In one embodiment of the invention, the fiber blending slurry is heated to a temperature of about 50°C to about 100°C. Other temperature ranges are about 70°C to about 100°C, about 80°C to about 100°C, and about 90°C to about 100°C.

[0184] Optionally, the fiber-mixed slurry is mixed in the shearing zone. The amount mixed is sufficient to disperse and remove a portion of the water-dispersible sulfonyl polyester from the multi-component fibers and to separate the non-water-dispersible polymer microfibers. In one embodiment of the invention, 90% of the sulfonyl polyester is removed. In another embodiment, 95% of the sulfonyl polyester is removed, and in yet another embodiment, 98% or more of the sulfonyl polyester is removed. The shearing zone can include any type of equipment that provides the shearing action necessary to disperse and remove a portion of the water-dispersible sulfonyl polyester from the multi-component fibers and to separate the non-water-dispersible polymer microfibers. Examples of such equipment include, but are not limited to, pulpers and beaters.

[0185] The water-dispersible sulfonyl polyester in the multi-component fiber is dispersed and separated from the non-water-dispersible polymer fibers after contact with water and heating to produce a slurry mixture comprising the sulfonyl polyester dispersion and the non-water-dispersible polymer microfibers. The non-water-dispersible polymer microfibers can then be separated from the sulfonyl polyester dispersion by any method known in the art. For example, the slurry mixture can be guided through separation equipment such as screens and filters. Optionally, the non-water-dispersible polymer microfibers can be washed once or multiple times to remove more water-dispersible sulfonyl polyester.

[0186] The removal of water-dispersible sulfonyl polyester can be determined by physical observation of the slurry mixture. If most of the water-dispersible sulfonyl polyester has been removed, the water used to rinse the non-water-dispersible polymer microfibers will be clear. If the water-dispersible sulfonyl polyester is still being removed, the water used to rinse the non-water-dispersible polymer microfibers may be emulsified. Furthermore, if water-dispersible sulfonyl polyester remains on the non-water-dispersible polymer microfibers, the microfibers may feel somewhat sticky to the touch.

[0187] Water-dispersible sulfonated polyesters can be recovered from sulfonated polyester dispersions by any method known in the art.

[0188] In another embodiment of the invention, non-aqueous polymer microfibers comprising at least one non-aqueous polymer are provided, wherein the non-aqueous polymer microfibers have an equivalent diameter of less than 5 micrometers and a length of less than 25 millimeters. These non-aqueous polymer microfibers are produced by the aforementioned method for producing microfibers. In another aspect of the invention, the non-aqueous polymer microfibers have an equivalent diameter of less than 3 micrometers and a length of less than 25 millimeters. In other embodiments of the invention, the non-aqueous polymer microfibers have an equivalent diameter of less than 5 micrometers or less than 3 micrometers. In other embodiments of the invention, the non-aqueous polymer microfibers may have a length of less than 12 millimeters; less than 10 millimeters, less than 6.5 millimeters, and less than 3.5 millimeters. Non-aqueous polymer microfibers are produced once the domains or segments in the multi-component fiber are separated.

[0189] This invention also includes a fiber article comprising the water-dispersible fibers, multicomponent fibers, microdenier fibers, or non-water-dispersible polymer microfibers described above. The term "fiber article" should be understood to mean any article having or resembling fibers. Non-limiting examples of fiber articles include multifilament fibers, yarns, cords, tapes, fabrics, wet-laid webs, dry-laid webs, meltblown webs, spunbond webs, thermally bonded webs, hydraulically entangled webs, nonwoven webs and fabrics, and combinations thereof; articles having one or more layers of fibers, such as multilayer nonwoven materials, laminates and composites made from these fibers, gauze, bandages, diapers, training pants, tampons, surgical gowns and masks, sanitary napkins; and so on. Furthermore, non-water-dispersible microfibers can be used in air filtration, liquid filtration, food preparation filtration, medical application filtration, and filter media in papermaking processes and paper products. Additionally, fiber articles can include replacement inserts for various personal hygiene and cleaning products. The fibrous articles of the present invention can be bonded, laminated, attached to, or combined with other materials, which may or may not be water-dispersible. Fiber articles, such as nonwoven fabric layers, can be bonded to flexible plastic films or backings of non-water-dispersible materials such as polyethylene. For example, such components can be used as a part of disposable diapers. Furthermore, fibrous articles can be produced by highly categorized combinations of processes such as meltblown, spunbond, film, or membrane structures, achieved by overblowing fibers onto another substrate.

[0190] The fiber articles of this invention include nonwoven fabrics and webs. Nonwoven fabrics are defined as fabrics made directly from webs without any weaving or knitting operations. The Textile Institute defines nonwovens as fabric structures made directly from fibers rather than yarns. These fabrics are typically made of continuous filaments or fiber webs or wadding, and are reinforced by bonding using various techniques, including but not limited to adhesive bonding, mechanical interlocking by needle punching or fluid jet entanglement, thermal bonding, and stitch bonding. For example, the multicomponent fibers of this invention can be formed into fabrics using any known fabric-forming method. The resulting fabric or web can be transformed into a microdenier fiber web by applying sufficient force to break the multicomponent fibers or by contacting the web with water to remove the sulfonated polyester, leaving the remaining microdenier fibers.

[0191] In another embodiment of the invention, a method for producing microdenier fiber webs is provided, comprising: (A) spinning a water-dispersible sulfonyl polyester having a glass transition temperature (Tg) of at least 57°C and one or more non-water-dispersible polymers immiscible with the sulfonyl polyester into multicomponent fibers, wherein the multicomponent fibers comprise at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol. The sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol and... The sulfonyl polyester comprises (iii) a sulfonyl polyester containing substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a total sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a temperature of at least 57°C. The glass transition temperature of the sulfonyl polyester, wherein the sulfonyl polyester contains substantially equimolar proportions of acid molar repeating units (100 mol percent) and hydroxyl molar repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acid and hydroxyl molar repeating units equaling 200 mol percent; wherein the multicomponent fiber has a plurality of segments comprising a non-aqueous dispersible polymer, wherein the segments are substantially isolated from each other by sulfonyl polyester interposed between said segments; (B) overlapping and collecting the multicomponent fiber of step A to form a nonwoven web; and (C) contacting the nonwoven web with water to remove the sulfonyl polyester, thereby forming a microdenier fiber web.

[0192] In another embodiment of the invention, the multicomponent fibers used contain less than 10% by weight of pigment or filler, based on the total weight of the fibers.

[0193] In another embodiment of the invention, a method for a microfiber web is provided, comprising: (A) extruding at least one water-dispersible sulfonyl polyester and one or more non-water-dispersible polymers immiscible with the water-dispersible sulfonyl polyester into a multicomponent extrudate, the multicomponent extrudate having a plurality of domains comprising non-water-dispersible polymers, wherein the domains are substantially isolated from each other by water-dispersible sulfonyl polyesters interposed between the domains; wherein the multicomponent fiber comprises at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) (i) a sulfonyl polyester comprising residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acid moiety repeating units (100 mol percent) and hydroxyl moiety repeating units (100 mol percent), and wherein all said mole percentages are based on the sum of all acid and hydroxyl moiety repeating units being equal to 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol. The sulfonyl polyester comprises: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (iii) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1, wherein the sulfonyl polyester comprises substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; and (d) residues of 1,4-cyclohexanediethanol; and (e) the residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; (B) melt-stretching the multicomponent extrudate at a speed of at least about 2000 m / min to produce multicomponent fibers; (C) collecting the multicomponent fibers from step (B) to form a nonwoven web; and (D) contacting the nonwoven web with water to remove the sulfonyl polyester, thereby forming a microdenier fiber web.

[0194] Prior to step (C), the method may further include a step of hydroentanglement of the multicomponent fibers of the nonwoven web. In one embodiment of the invention, the hydroentanglement step results in a loss of less than about 20% by weight, or less than 15% by weight, or less than 10% by weight of the sulfonyl polyester contained in the multicomponent fibers. To facilitate the goal of reducing sulfonyl polyester loss during hydroentanglement, in one embodiment of the invention, the water used during the method may have a temperature of less than about 45°C, less than about 35°C, or less than about 30°C. In one embodiment of the invention, to minimize the loss of sulfonyl polyester in the multicomponent fibers, the water used during hydroentanglement is as close to room temperature as possible. Conversely, the removal of the sulfonyl polyester polymer during step (D) may be carried out using water at a temperature of at least about 45°C, at least about 60°C, or at least about 80°C.

[0195] After hydraulic entanglement and before step (D), the nonwoven web may undergo a heat-setting step, including heating the nonwoven web to a temperature of at least about 100°C or at least about 120°C. The heat-setting step releases internal fiber stress and helps produce dimensionally stable fabric products. In other embodiments of the invention, when the heat-set material is reheated to the temperature it was heated to during the heat-setting step, it exhibits a surface area shrinkage of less than about 5%, less than about 2%, or less than about 1% of its initial surface area.

[0196] Furthermore, the method of the present invention may include the step of stretching multi-component fibers at a fiber speed of at least 2000 m / min, at least about 3000 m / min, at least about 4000 m / min, or at least about 5000 m / min.

[0197] In another embodiment of the invention, a nonwoven article comprising non-aqueous polymer microfibers can be produced. The nonwoven article comprises non-aqueous polymer microfibers and is prepared by a method selected from dry web forming and wet web forming. Multicomponent fibers and methods for producing non-aqueous polymer microfibers have previously been disclosed in the specification.

[0198] In one embodiment of the invention, at least 1% of the non-aqueous dispersible polymer microfibers are included in the nonwoven article. Other amounts of the non-aqueous dispersible polymer microfibers included in the nonwoven article are at least 10%, at least 25%, and at least 50%.

[0199] In another aspect of the invention, the nonwoven article may further include at least one other fiber. The other fiber may be any fiber known in the art, depending on the type of nonwoven article to be produced. In one embodiment of the invention, the other fiber may be selected from cellulose fiber pulp, glass fiber, polyester fiber, nylon fiber, polyolefin fiber, rayon fiber, cellulose ester fiber, and mixtures thereof.

[0200] Nonwoven articles may further contain at least one additive. Additives include, but are not limited to, starch, fillers, and binders. Other additives are discussed in other parts of this disclosure.

[0201] Generally, the manufacturing methods for producing these nonwoven products from non-aqueous dispersible microfibers made from multi-component fibers can be divided into the following groups: dry web forming, wet web forming, combinations of these methods, or other nonwoven methods.

[0202] Dry-laid nonwovens are typically manufactured using short-fiber processing machinery designed to manipulate fibers in a dry state. These methods include mechanical methods such as carding, aerodynamics, and other air-jet web-forming methods. This category also includes nonwovens made from filaments in the form of tows, and fabrics composed of short fibers and sewn filaments or yarns, i.e., stitch-knitted nonwovens. Carding is a method of untangling, cleaning, and blending fibers to prepare a web for further processing into nonwovens. This method primarily involves arranging fibers together, binding them together to form a web through mechanical entanglement and fiber-fiber friction. Carding machines are typically configured with one or more master cylinders, rollers or stationary tops, one or more doffing frames, or various combinations of these main components. An example of a carding machine is a roller carding machine. Carding involves combing or processing segmented multi-component fibers or non-aqueous polymer microfibers between carding points on a series of cooperating carding rollers. Other types of carding machines include carding machines, cotton carding machines, and random carding machines. A rewinding machine can also be used to arrange these fibers.

[0203] In dry web forming processes, segmented multicomponent fibers or non-aqueous polymer microfibers can also be arranged using airflow web forming. These fibers are guided by airflow onto a collector, which can be a flat conveyor or a roller.

[0204] Extruded webs can also be produced from the multicomponent fibers of this invention. Examples include spunbond and meltblown. Extrusion technology is used to produce spunbond, meltblown, and porous membrane nonwovens. These nonwovens are manufactured using machinery associated with polymer extrusion methods such as melt spinning, film casting, and extrusion coating. The nonwovens are then contacted with water to remove water-dispersible sulfonyl polyester, thereby producing nonwovens containing non-water-dispersible polymer microfibers.

[0205] In spunbond fabrication, water-dispersible sulfonated polyesters and non-water-dispersible polymers are directly converted into fabrics by extruding multi-component filaments, orienting them into bundles or groups, layering them on a conveying screen, and interlocking them. Interlocking can be achieved through thermal fusion, mechanical entanglement, hydraulic entanglement, chemical adhesives, or a combination of these methods.

[0206] Meltblown fabrics are also made directly from water-dispersible sulfonated polyesters and non-water-dispersible polymers. The polymer is melted and extruded. As the melt passes through the extrusion orifice, it is blown in with hot air. The airflow causes the molten polymer to be finer and solidified. The multi-component fibers can then be separated from the airflow as a web and compressed between heated rollers.

[0207] Nonwoven products can also be produced using a combination of spunbond and melt-bond methods.

[0208] Wet web forming processes involve using papermaking techniques to produce nonwoven products. These nonwoven products are manufactured using machinery related to pulp fiberization, such as hammer mills and paper forming. For example, the pulp is pumped onto a continuous screen designed to manipulate short fibers in the fluid.

[0209] In one embodiment of the wet web forming process, non-aqueous dispersible polymer microfibers are suspended in water and carried to the forming unit, where water is discharged through a forming screen and fibers are deposited on the screen wires.

[0210] In another embodiment of the wet web forming process, the non-aqueous dispersible polymer microfibers are dehydrated on a screen or wire mesh that rotates at the start of a hydroforming machine through a dehydration module (absorption tank, foil, and curing agent) at speeds up to 1500 m / min. The sheet is then placed on the wire mesh or screen, and dehydration continues until the solids content is approximately 20-30% by weight. The sheet can then be pressed and dried.

[0211] In another embodiment of the wet web forming process, a method is provided comprising: (A) optionally, rinsing non-aqueous polymer microfibers with water; (B) adding water to the non-aqueous polymer microfibers to produce a non-aqueous polymer microfiber slurry; (C) optionally, adding other fibers and / or additives to the non-aqueous polymer microfibers or slurry; and (D) transferring the slurry containing the non-aqueous polymer microfibers to a wet web forming nonwoven zone to produce a nonwoven article.

[0212] In step a), the number of rinses depends on the specific application of the selected non-aqueous polymer microfibers. In step b), sufficient water is added to the microfibers to enable them to be fed into the wet-laid nonwoven zone.

[0213] The wet-laid nonwoven zone includes any equipment known in the art for producing wet-laid nonwoven articles. In one embodiment of the invention, the wet-laid nonwoven zone includes at least one screen, mesh, or sieve to remove water from a non-aqueous dispersible polymer microfiber slurry.

[0214] In another embodiment of the wet web forming process, a method is provided comprising: (A) contacting diced multicomponent fibers with water to remove a portion of a water-dispersible sulfonyl polyester to produce a non-water-dispersible polymer microfiber slurry; wherein the non-water-dispersible polymer microfiber slurry comprises non-water-dispersible polymer microfibers and a water-dispersible sulfonyl polyester; wherein the diced multicomponent fibers comprise at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols The alcohols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol. The sulfonyl polyester comprises a residue of diethylene glycol in a molar ratio of less than 1:1 to a residue of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a total sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) a residue of diethylene glycol. The residues, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 mol percent) and hydroxyl repetitive units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repetitive units equaling 200 mol percent; (B) optionally, rinsing the non-aqueous dispersible polymer microfibers with water; (C) optionally, adding other fibers and / or additives to the non-aqueous dispersible polymer slurry; and (D) transferring the slurry containing the non-aqueous dispersible polymer microfibers to a wet-laid nonwoven zone to produce a nonwoven article.

[0215] In another embodiment of the invention, a non-aqueous polymer microfiber slurry is mixed before being transferred to the wet web forming nonwoven zone.

[0216] Web bonding processes can also be used to produce nonwoven products. These can be categorized into chemical and physical processes. Chemical bonding refers to the use of water-based and solvent-based polymers to bond fibers and / or webs together. These adhesives can be applied by saturation, impregnation, spraying, printing, or as foam application. Physical bonding methods include thermal methods such as calendering and hot air bonding, and mechanical methods such as needle punching and hydraulic entanglement. Needling, or needle-punching, is a process that mechanically interlocks fibers by physically moving some fibers from a near-horizontal position to a near-vertical position. Needling can be performed using a knitting machine. Knitting machines typically include a web feeding mechanism, a needle beam consisting of a needle plate with holding needles, a stripping plate, a base plate, and a fabric take-up mechanism.

[0217] Sewing is a mechanical bonding method that uses knitted elements, with or without yarn, to interlock a web of fibers. Examples of sewing machines include, but are not limited to, Maliwatt, Arachne, Malivile, and Arabeva.

[0218] Nonwoven fabrics are bonded together by: 1) mechanical fiber cohesion and interlocking in a web or matte fabric; 2) various techniques of fiber fusion bonding, including the use of bonding fibers, taking advantage of the thermoplastic properties of certain polymers and polymer blends; 3) the use of bonding resins such as starch, casein, cellulose derivatives, or synthetic resins such as acrylic latex or urethane; 4) powder adhesives; or 5) combinations thereof. Fibers are typically deposited randomly, but orientation in one direction is possible, followed by bonding / adhesion using one of the methods described above.

[0219] The fiber articles of the present invention may further comprise one or more layers of water-dispersible fibers, multi-component fibers, or microdenier fibers. The fiber layer may be one or more nonwoven fabric layers, loosely bonded overlapping fiber layers, or combinations thereof. Additionally, the fiber articles may include personal and hygiene care products, such as, but not limited to, childcare products like baby diapers; training pants; adult care products like adult diapers and adult incontinence pads; feminine care products like sanitary napkins, underwear linings, and tampons; wipes; fiber-containing cleaning products; medical and surgical care products like medical wipes, tissues, gauze, examination bed covers, surgical masks, surgical gowns, bandages, and wound dressings; fabrics; elastic yarns, wipes, tapes, other protective barriers, and packaging materials. The fiber articles may be used to absorb liquids or may be pre-wetted with various liquid compositions and used to deliver these compositions to surfaces. Non-limiting examples of liquid compositions include detergents; wetting agents; cleansing agents; and skin care products such as cosmetics, ointments, pharmaceuticals, lubricants, and fragrances. Fiber products may also include various powders and granules to improve absorbency or serve as transport carriers. Examples of powders and granules include, but are not limited to, talc, starch, various absorbent, water-dispersible, or water-swellable polymers such as superabsorbent polymers, sulfonated polyesters and poly(vinyl alcohol), silica, pigments, and microcapsules. Additives may also be present, but are not mandatory, depending on the specific application. Examples of additives include, but are not limited to, oxidizing stabilizers, UV absorbers, colorants, pigments, opacifiers (matting agents), fluorescent whitening agents, fillers, nucleating agents, plasticizers, viscosity modifiers, surface modifiers, antimicrobial agents, disinfectants, cold rheology inhibitors, branching agents, and catalysts.

[0220] In addition to being water-dispersible, the aforementioned fiber products can be flushable. As used herein, the term "fluffable" means that they can be flushed away in a conventional washroom and can be introduced into a municipal or residential wastewater treatment system without causing blockage or clogging in the washroom or wastewater system.

[0221] The fibrous articles may further include a water-dispersible film comprising a second water-dispersible polymer. The second water-dispersible polymer may be the same as or different from the aforementioned water-dispersible polymer used in the fibers and fibrous articles of the present invention. In one embodiment, for example, the second water-dispersible polymer may be an additional sulfonated polyester, which thus comprises: (A) about 50 to about 96 mol% of one or more residues of isophthalic acid or terephthalic acid, based on total acid residues; (B) about 4 to about 30 mol% of residues of sodium sulfonated isophthalic acid, based on total acid residues; and (C) one or more diol residues, based on total diol residues, wherein at least 15 mol% is having the structure H-(OCH2-CH2). n-OH poly(ethylene glycol), where n is an integer from 2 to about 500; (D) based on total repeating units, 0 to about 20 mol% of residues of a branched monomer having three or more functional groups, wherein said functional groups are hydroxyl, carboxyl, or combinations thereof. As described above, additional sulfonyl polyesters can be blended with one or more complementary polymers to modify the properties of the resulting fibrous articles. Depending on the application, the complementary polymer may or may not be water-dispersible. The complementary polymer may be miscible or miscible with the additional sulfonyl polyester.

[0222] Additional sulfonyl polyesters may contain other concentrations of isophthalic acid residues, for example, about 60 to about 95 mol% and about 75 to about 95 mol%. Further examples of isophthalic acid residue concentration ranges are about 70 to about 85 mol%, about 85 to about 95 mol%, and about 90 to about 95 mol%. Additional sulfonyl polyesters may also include about 25 to about 95 mol% of diethylene glycol residues. Further examples of diethylene glycol residue concentration ranges include about 50 to about 95 mol%, about 70 to about 95 mol%, and about 75 to about 95 mol%. Additional sulfonyl polyesters may also include ethylene glycol and / or 1,4-cyclohexanediethanol residues. Typical concentration ranges of CHDM residues are about 10 to about 75 mol%, about 25 to about 6 mol%, and about 40 to about 60 mol%. Typical concentration ranges of ethylene glycol residues are about 10 to about 75 mol%, about 25 to about 65 mol%, and about 40 to about 60 mol%. In another embodiment, the additional sulfonated polyester comprises about 75 to about 96 mol% of isophthalic acid residues and about 25 to about 95 mol% of diethylene glycol residues.

[0223] According to the present invention, sulfonated polyester film assemblies of fibrous articles can be produced in the form of single-layer or multi-layer films. Single-layer films can be produced by conventional casting techniques. Multi-layer films can be produced by conventional lamination methods, etc. The films can have any suitable thickness, but the total thickness will typically be about 2 to about 50 mil.

[0224] Film-containing fiber articles may include one or more layers of water-dispersible fiber layers as described above. The fiber layer may be one or more nonwoven fabric layers, loosely bonded layers of overlapping fibers, or combinations thereof. Additionally, film-containing fiber articles may include personal and hygiene products, as described above.

[0225] As previously mentioned, fibrous articles may also include various powders and granules to improve absorbency or serve as a transport carrier. Therefore, in one embodiment, our fibrous articles comprise powders that include a third water-dispersible polymer, which may be the same as or different from the water-dispersible polymer components described above. Other examples of powders and granules include, but are not limited to, talc, starch, various absorbent, water-dispersible, or water-swellable polymers such as poly(acrylonitrile), sulfonated polyesters, and poly(vinyl alcohol), silica, pigments, and microcapsules.

[0226] Beyond the applications described above, our novel fibers and fiber products have numerous potential uses. One emerging application involves meltblowing films or nonwoven fabrics onto flat, curved, or shaped surfaces to provide a protective layer. Such a layer can provide surface protection for durable equipment during transport. At the destination, the outer layer of the sulfonated polyester can be washed off before the equipment is put into use. A further implementation of this general application concept may involve personal protective equipment to provide a temporary barrier layer for reusable or limited-use clothing or coverings. For the military, activated carbon and chemical absorbents can be sprayed onto a tapered filament pattern just before the collector, allowing the meltblown matrix to anchor these entities to exposed surfaces. By meltblowing onto another layer, the chemical absorbent can even be altered in the forward operation area when a threat arises.

[0227] A key advantage inherent in sulfonated polyesters is the ease with which the polymer can be removed or recovered from aqueous dispersions via flocculation or precipitation through the addition of ionic moieties (i.e., salts). Other methods, such as pH adjustment, the addition of non-solvents, freezing, etc., can also be used. Therefore, fibrous products, such as outer protective clothing, can potentially be safely disposed of at much lower quantities after successful use of protective barriers, and even if the polymer becomes hazardous waste, for treatment using accepted procedures such as incineration.

[0228] It is known that insoluble or dried sulfonated polyesters form strong adhesive bonds to a variety of substrates, including but not limited to short fiber pulp, cotton, acrylic resins, rayon, lyocell, PLA (polylactic acid), cellulose acetate, cellulose acetate propionate, polyethylene terephthalate, polybutylene terephthalate, poly(trimethylene) terephthalate, polycyclohexyl terephthalate, copolyesters, polyamides (nylon), stainless steel, aluminum, treated polyolefins, PAN (polyacrylonitrile), and polycarbonate. Therefore, our nonwoven fabrics can be used as laminating adhesives or binders, which can be bonded using known techniques such as thermal, radio frequency (RF), microwave, and ultrasonic methods. Modification of sulfonated polyesters to enable RF activation is disclosed in many recent patents. Thus, our novel nonwoven fabrics can possess dual or even multiple functions beyond adhesive properties. For example, disposable baby diapers can be obtained in which the nonwoven fabric of the present invention serves as a water-responsive adhesive for the final fiber bundles and as a fluid management component.

[0229] The present invention also provides a method for use in water-dispersible sulfonated polyester fibers, comprising:

[0230] (A) Heating an aqueous polymer composition to a temperature above its flow point, wherein the polymer composition comprises at least one sulfonyl polyester selected from the group consisting of: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all of the stated molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; and (c) residues of 1,4-cyclohexanediethanol. and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) p-phenylene... (c) residues of dicarboxylic acid; (d) residues of at least one sulfonyl monomer; (e) residues of 1,4-cyclohexanediethanol; and (f) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; and (ii) melt-spun filament.

[0231] As described above, water-dispersible polymers can optionally be blended with sulfonated polyesters. Additionally, non-water-dispersible polymers can optionally be blended with sulfonated polyesters to form blends that are immiscible. As used herein, the term "flowpoint" refers to a temperature at which the viscosity of the polymer composition allows for extrusion or other forms of processing via a spinneret or extrusion die.

[0232] Water-dispersible sulfonated polyester fibers are prepared via a melt-blowing method. The polymer is melted in an extruder and forced through a die. The extrudate exiting the die is rapidly ablated to an ultrafine diameter by the help of hot, high-speed air. Fiber orientation, cooling rate, and glass transition temperature (Tg) are all factors considered.g The filament diameter and crystallization rate are important because they affect the polymer's viscosity and processing properties during the filamentation process. The filaments are collected on replaceable surfaces, such as conveyor belts, cylindrical drums, rotating mandrels, etc. Pre-drying of the pellets (if required), extrusion zone temperature, melt temperature, screw design, throughput rate, air temperature, airflow rate (speed), die air gap and retraction components, nose orifice size, die temperature, die-collector (DCP) distance, quenching environment, collector speed, and post-treatment are all factors affecting product properties such as filament diameter, basis weight, web thickness, pore size, softness, and shrinkage. High-speed air can also be used, thus moving the filaments in a slightly random manner, resulting in large-scale interlacing. If the conveyor belt passes under the die, nonwoven fabrics can be produced through a combination of filament overlay, mechanical cohesion, and thermal bonding. They can also be overblown onto another substrate, such as a spunbond layer or padding. If the filaments are wound on a rotating mandrel, a cylindrical product is formed. The layup of water-dispersible fibers can also be achieved through spunbonding.

[0233] Therefore, the present invention also provides a method for producing a water-dispersible, nonwoven fabric comprising: (A) heating a water-dispersible polymer composition to a temperature above its flow point, wherein the polymer composition comprises at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repetitive units (100 molar percentages) and hydroxyl repetitive units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repetitive units equal to 200 molar percentages; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentages of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) diethylene glycol. The residues of the sulfonyl polyester, wherein the sulfonyl polyester comprises a diethylene glycol residue and a 1,4-cyclohexanediethanol residue in a molar ratio of less than 1:1, wherein the sulfonyl polyester contains substantially equimolar proportions of acid molar repeating units (100 mol percent) and hydroxyl molar repeating units (100 mol percent), and wherein all said molar percentages are based on a total sum of all acid and hydroxyl molar repeating units equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) isophthalic acid residues; (b) terephthalic acid residues; (c) at least one sulfonyl monoester. The sulfonyl polyester comprises (a) residues of the body; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acid molar repeating units (100 mol percent) and hydroxyl molar repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acid and hydroxyl molar repeating units equaling 200 mol percent; (B) melt spinning filaments; and (C) overlapping and collecting the filaments of step (B) to form a nonwoven fabric. As described above, the water-dispersible polymer may optionally be blended with the sulfonyl polyester. Furthermore, the non-water-dispersible polymer may optionally be blended with the sulfonyl polyester to form a blend such that the blend is an immiscible blend. Water-dispersible sulfonyl polyesters have been previously described in this disclosure.

[0234] In some embodiments of the invention, the water-wetted microfiber product (wet pulp board) produced after the multi-component fibers have been cut, washed, and excess water drained can be used directly (i.e., without further drying) in a wet-laid nonwoven process. Direct use of the wet pulp board product in the wet-laid nonwoven process avoids the need for complete drying of the wet pulp board, thereby saving significant energy and equipment costs. When the wet pulp board production equipment is located far from the equipment used to manufacture wet-laid nonwovens, the wet pulp board can be packaged and transported from the wet pulp board production location to the nonwoven production location. This wet pulp board composition will be described in further detail below.

[0235] One embodiment of the present invention relates to a wet pulp board composition comprising water and a plurality of synthetic fibers. Water may constitute at least 50, 55, or 60% by weight and / or no more than 90, 85, or 80% by weight of the wet pulp board composition. Synthetic fibers may constitute at least 10, 15, or 20% by weight and / or no more than 50, 45, or 40% by weight of the wet pulp board composition. The combination of water and synthetic fibers constitutes at least 95, 98, or 99% by weight of the wet pulp board composition. The synthetic fibers may have a length of at least 0.25, 0.5, or 1 mm and / or no more than 25, 10, or 2 mm. The synthetic fibers may have a minimum transverse dimension of at least 0.1, 0.5, or 0.75 micrometers and / or no more than 10, 5, or 2 micrometers.

[0236] As used herein, “minimum transverse dimension” refers to the minimum dimension of the fiber measured perpendicular to the fiber’s elongation axis using external calipers. As used herein, “maximum transverse dimension” refers to the maximum dimension of the fiber measured perpendicular to the fiber’s elongation axis using external calipers. Figure 1a , 1b 1c describes how to measure these dimensions in various fiber cross-sections. Figure 1a , 1a In 1c, "TDmin" is the minimum transverse dimension, and "TDmax" is the maximum transverse dimension. As used herein, "external caliper method" refers to a method of measuring the external dimensions of a fiber, wherein the measured dimension is the distance between two parallel lines separated by two coplanar lines, with the fiber located between the two parallel lines, and each parallel line contacting the outer surface of the fiber on approximately opposite sides of the fiber. All fiber dimensions (e.g., length, minimum transverse dimension, and maximum transverse dimension) provided herein are average dimensions of fibers belonging to a particular group.

[0237] The wet pulp board composition may also contain a fiber finishing composition in an amount of at least 10, 50, or 100 ppmw and / or no more than 1,000, 500, or 250 ppmw. In one embodiment, the fiber finishing composition may contain oils, waxes, and / or fatty acids. In another embodiment, the fiber finishing composition may include naturally derived fatty acids and / or naturally derived oils. In yet another embodiment, the fiber finishing composition includes mineral oil, stearate, sorbitan ester, and / or hoof oil. In still another embodiment, the fiber finishing composition contains mineral oil.

[0238] The wet slurry board composition may further comprise at least 0.001, 0.01, or 0.1% and / or no more than 5, 2, or 1% by weight of a water-dispersible polymer. In one embodiment, the water-dispersible polymer comprises at least one sulfonated polyester. Sulfonated polyesters have been previously described in this disclosure.

[0239] The non-aqueous dispersible synthetic polymer of the wet slurry board composition may be selected from polyolefins, polyesters, copolyesters, polyamides, polylactic acid, polycaprolactone, polycarbonate, polyurethane, cellulose esters, acrylics, polyvinyl chloride, and blends thereof. In one embodiment, the non-aqueous dispersible synthetic polymer is selected from polyethylene terephthalate homopolymers, polyethylene terephthalate copolymers, polybutylene terephthalate, polypropylene terephthalate, nylon 6, nylon 66, and blends thereof.

[0240] The wet pulp board composition can be prepared by a method comprising the following steps: (A) producing a multicomponent fiber comprising at least one water-dispersible sulfonyl polyester and one or more non-water-dispersible synthetic polymers immiscible with the water-dispersible sulfonyl polyester, wherein the multicomponent fiber has an initial denier of less than 15 dpf; wherein the multicomponent fiber comprises at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester comprises: (i) residues of at least one dicarboxylic acid; (ii) residues of at least one sulfonyl monomer; and (iii) residues of two or more diols, wherein the diols comprise 1,4-cyclohexanediethanol and diethylene glycol. The ester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol and residues of 1,4-cyclohexanediethanol. The molar ratio of the groups is less than 1:1, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains the groups (a) Acid-repeating units (100 mol percent) and hydroxyl-repeating units (100 mol percent) in equal molar proportions, wherein all said molar percentages are based on the sum of all acid and hydroxyl-repeating units equaling 200 mol percent; (b) Cutting multicomponent fibers into segments less than 25 mm in length; (c) Contacting the segments of multicomponent fibers with washing water to remove water-dispersible sulfopolyester, thereby forming a slurry of synthetic fibers in a sulfopolyester dispersion, wherein the sulfopolyester dispersion comprises water and at least a portion of the sulfopolyester; and (d) Removing at least a portion of the sulfopolyester dispersion from the slurry, thereby producing a wet slurry board composition.

[0241] As described above, the wet pulp board composition can be directly used in the wet web forming process to prepare nonwoven articles. To use the wet pulp board in the wet web forming process, the wet pulp board composition is transferred from its production location to the wet web forming nonwoven zone. The wet pulp board composition can be bonded with additional fibers in and / or immediately upstream of the wet web forming nonwoven zone. These additional fibers can be selected from cellulose fiber pulp, inorganic fibers, polyester fibers, nylon fibers, lyocell fibers, polyolefin fibers, rayon fibers, cellulose ester fibers, and combinations thereof.

[0242] As part of the wet web forming process, the wet sizing board composition may be combined with dilution water in and / or immediately upstream of the wet web forming nonwoven area. The dilution water and wet sizing board may be combined in an amount such that at least 50, 75, 90, or 95 parts by weight of dilution water are used per portion of wet sizing board.

[0243] In other embodiments of the present invention, such as Figure 2 , 3a As shown in 3b and 4, a method for producing a stream of microfiber products is provided. Multicomponent fibers have been previously discussed in this disclosure. Further disclosures regarding multicomponent fibers are provided in the following patents and patent applications: U.S. Patents 6,989,193; 7,635,745; 7,902,094; 7,892,993; 7,687,143; and U.S. Patent Applications 12 / 199,304; 12 / 909,574; 13 / 273,692; 13 / 273,648; 13 / 273,710; 13 / 273,720; 13 / 273,929, 13 / 273,937; 13 / 273,727, 13 / 27 3,737; 13 / 273,745; 13 / 273,749; 12 / 966,502; 12 / 966,507; 12 / 975,450; 12 / 975,452; 12 / 975,456; 13 / 053,615; 13 / 352,362; 13 / 433,812; 13 / 433,854; 61 / 471,259; 61 / 472,964; and 61 / 558,744, all of which are incorporated herein by reference to the extent that they do not contradict the statements herein.

[0244] The terms “wet slurry board” and “microfiber product flow” are used interchangeably in this disclosure.

[0245] One-step process for producing short-cut microfibers

[0246] In such Figure 2In one embodiment of the invention shown, a method for producing a microfiber product stream is provided. The method includes: (A) contacting chopped multicomponent fibers 101 having a length of less than 25 mm with a heated aqueous stream 801 in a fiber opening zone 400 to remove a portion of a water-dispersible sulfonated polyester to produce an opened microfiber slurry 401; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonated polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonated polyester; wherein the heated aqueous stream 801 is at a temperature of at least 40°C; wherein the opened microfiber slurry 401 comprises water, microfibers, and a water-dispersible sulfonated polyester; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonated polyester selected from: (i) sulfonated polyester, It comprises: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein the diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all of the molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol in a molar ratio of less than 1:1 to residues of 1,4-cyclohexanediethanol, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 molar percentages) and hydroxyl repeating units (100 molar percentages), and wherein all said molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 molar percentages; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) at least (a) a residue of a sulfonyl monomer; (d) a residue of 1,4-cyclohexanediethanol; and (e) a residue of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units equaling 200 mol percent; and (B) feeding an opened microfiber slurry 401 to a primary solid-liquid separation zone 500 to produce a microfiber product stream 503 and a first mother liquor stream 501; wherein the first mother liquor stream 501 comprises water and a water-dispersible sulfonyl polyester.

[0247] In this embodiment of the invention, such as Figure 4 The fiber slurry zone 200, mixing zone 300, and fiber opening zone 400 shown are combined into a single unit operation in the opening treatment zone 1100. The opening treatment zone 1100 includes the fiber opening zone 400.

[0248] The treated aquifer stream 103 used in this method can be generated by sending the aquifer stream 102 to the aquifer treatment zone 1000 to produce the treated aquifer stream 103. The aquifer stream contains water. In embodiments of the invention, the concentration of monovalent metal cations in the treated aquifer stream 103 can be less than about 1000 ppm by weight, less than about 500 ppm by weight, less than about 100 ppm by weight, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from the aquifer stream 102 is a function of the aquifer treatment zone 1000. In other embodiments of the invention, the concentration of divalent and polyvalent cations is less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of the stream 103 can be in the range of groundwater temperature to about 40°C.

[0249] The treatment of the aqueous stream 102 in the aqueous treatment zone 1000 can be performed in any manner known in the art. In one embodiment, the aqueous treatment zone 1000 includes a distillation apparatus in which water vapor is generated and condensed to produce a treated aqueous stream 103. In another embodiment, water is fed to a reverse osmosis membrane capable of separating monovalent and divalent metal cations from water to produce a treated aqueous stream 103. In yet another embodiment, water is fed to an ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal cations. In still another embodiment, water may be fed to a commercial water softening unit to produce a treated aqueous stream 103 having an acceptable low concentration of divalent and polyvalent metal cations. It should be understood that any combination of these water treatment options can be employed to achieve the desired treated water characteristics.

[0250] The treated aqueous stream 103 can be sent to any location in the process where it is needed. In one embodiment, a portion of the stream 103 is sent to the primary solid-liquid separation zone 500 to be used as a washing solution and / or a washing solution for the solids contained in the primary solid-liquid separation zone 500.

[0251] In one embodiment, at least a portion of the treated aqueous stream 103 is fed to a heat exchange zone 800 to generate a heated aqueous stream. One function of the heat exchange zone 800 is to generate a heated aqueous stream 801 at a specific and controlled temperature.

[0252] In one embodiment, the feedable stream to the heat exchange zone 800 is a treated aqueous feed stream 103 and a second mother liquor stream 601. In another embodiment, the feedable stream to the heat exchange zone 800 includes a treated aqueous feed stream 103, a portion of a primary recycled water stream 703, a portion of a first mother liquor stream 501, and a portion of a second mother liquor stream 601.

[0253] Any device known in the art for controlling the temperature of flow 801 can be used, including but not limited to any heat exchanger with steam for providing a portion of the required energy, any heat exchanger with a heat transfer fluid for providing a portion of the required energy, any heat exchanger with an electric heating element for providing a portion of the required energy, and any container or tank with direct steam injection in which steam condenses and the condensate mixes with water supplied to heat exchange zone 800. The multicomponent fiber flow 90 is fed to fiber cutting zone 100 to produce chopped multicomponent fiber flow 101. The multicomponent fiber can be any multicomponent structure known in the art. The multicomponent fiber comprises a water-dispersible sulfonated polyester and a non-water-dispersible polymer, as previously discussed in this disclosure.

[0254] Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the diced multicomponent fiber stream 101. In one embodiment, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or less than 2.5 mm.

[0255] A stream of diced multicomponent fibers 101 and a portion of a heated, treated, water-containing stream 801 are fed to a fiber opening zone 400 to produce an opened microfiber slurry 401. One function of the fiber opening zone 400 is to separate the water-dispersible polymer from the diced multicomponent fibers, such that at least a portion of the non-water-dispersible polymer microfibers are separated from the diced multicomponent fibers and suspended in the opened microfiber slurry 401. In another embodiment of the invention, approximately 50% to approximately 100% by weight of the non-water-dispersible polymer microfibers contained in the diced multicomponent fiber slurry 201 become suspended in the opened microfiber slurry liquid 401 as non-water-dispersible polymer microfibers and are no longer part of the diced multicomponent fibers. In other embodiments, about 75% to about 100% by weight, about 90% to about 100% by weight, or about 95% to about 100% by weight of the non-aqueous polymer microfibers contained in the segmented multicomponent fiber stream 201 become suspended in the open microfiber slurry 401 as non-aqueous polymer microfibers and are no longer part of the segmented multicomponent fibers.

[0256] The diameter or denier of the initial segmented multicomponent fibers in flow 201 affects the degree of separation between the water-dispersible sulfonyl polyester and the segmented multicomponent fibers in the fiber opening zone 400. Typical multicomponent fiber types typically have diameters ranging from about 12 micrometers to about 20 micrometers. Available multicomponent fibers can have larger initial diameters, approximately 40 micrometers or larger. The time required to separate the desired amount of water-dispersible sulfonyl polyester from the segmented multicomponent fibers increases with the diameter of the segmented multicomponent fibers in flow 201.

[0257] In this embodiment of the invention, such as Figure 4 The fiber pulping zone 200, mixing zone 300, and fiber opening zone 400 shown are combined and, as... Figure 2 This is accomplished in a single unit operation as shown. In this embodiment, the diced multicomponent fiber stream 101 is fed directly to the single unit operation, where it is mixed with a heated, moist stream 801 within the fiber opening zone 400. For example, a batch mixing apparatus, wherein the opening or washing of the diced multicomponent fibers is completed in a single batch mixing apparatus, wherein the diced multicomponent fiber stream 101 and the heated, moist stream 801 are directly added to the fiber opening zone 400. The fiber opening zone may include at least one mixing tank. In this embodiment, the combined functions of zones 200, 300, and 400 can be achieved as follows: Figure 5 This is accomplished in the continuous stirred tank reactor shown in b and 5c. In this embodiment, the combined functions of zones 200, 300, and 400 can be achieved in any batch or continuous mixing device capable of meeting the functional requirements of residence time, temperature, and mixing shear force necessary for the proper functioning of zones 200, 300, and 400.

[0258] The residence time, temperature, and shear force in the fiber opening zone 400 also affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. Conditions affecting the opening process in the fiber opening zone 400 include residence time, slurry temperature, and shear force, wherein the water temperature, residence time in the fiber opening zone 400, and the range of applied shear force are determined by the need to separate the water-dispersible sulfonyl polyester from the initial multicomponent fibers to a level sufficient to cause the non-water-dispersible polymer microfibers to separate and suspend in the continuous aqueous phase of the opened microfiber slurry 401.

[0259] The residence time, temperature, and shear force in the fiber opening zone 400 affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. The temperature of the fiber opening zone 400 can range from about 55°C to about 100°C, from about 60°C to about 90°C, or from about 65°C to about 80°C. The residence time in the fiber opening zone 400 can range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber opening zone 400 to maintain a suspension of the diced non-aqueous polymer microfibers, minimizing the sedimentation of the diced microfibers. In other embodiments of the invention, the mass per unit time of the segmented non-aqueous dispersible microfibers settling in the fiber opening zone 400 is less than about 5% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, less than about 3% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, or less than about 1% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the fiber opening zone 400.

[0260] Fiber opening in the fiber opening zone 400 can be performed in any equipment that allows for acceptable residence time, temperature, and mixing. Examples of suitable equipment include, but are not limited to, stirred batch reactors and continuous stirred tank reactors (such as...). Figure 6b and 6c (as shown) and pipes with sufficient flow to minimize the settling of solids from the slurry (such as...). Figure 6a (As shown). An example of a unit operation that completes fiber opening in zone 400 is a plug flow reactor, in which heated multi-component fiber slurry 301 is fed into a plug flow device in zone 400, typically a circular pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the packed volume within the device by the volumetric flow rate within the device. The mass velocity within the device is defined by dividing the cross-sectional area of ​​the flow channel by the volumetric flow rate of the liquid through the device.

[0261] In other embodiments of the invention, the fiber opening zone 400 may include a conduit or duct, wherein the mass velocity of the flow in the conduit may be in the range of 0.1 ft / s to about 20 ft / s, 0.2 ft / s to about 10 ft / s, or about 0.5 ft / s to about 5 ft / s. For the flow of fluid or slurry in a conduit or duct, the Reynolds number Re is a dimensionless number that can be used to describe turbulence or motion of fluid eddies that are irregular in direction and time. For flow in a conduit or duct, the Reynolds number is generally defined as:

[0262]

[0263] in:

[0264] ·D HL is the hydraulic diameter of the pipe (m).

[0265] Q is the volumetric flow rate (m³ / s). 3 / s).

[0266] • A is the cross-sectional area of ​​the pipe (m²) 2 ).

[0267] •v is the average velocity of an object relative to a fluid (SI unit: m / s).

[0268] μ is the dynamic viscosity of the fluid (Pa·s or N·s / m³). 2 Or kg / (m·s)).

[0269] ·v is the kinematic viscosity (ν=μ / ρ)(m 2 / s).

[0270] ρ is the density of the fluid (kg / m³) 3 ).

[0271] For flow in a pipe of diameter D, experimental observations show that for fully expanded flow, when Re D Laminar flow occurs when Re < 2000, while when Re D Turbulence occurs at temperatures above 4000. In the range of 2300 to 4000, both laminar and turbulent flow (“transitional” flow) are possible, depending on other factors such as pipe roughness and flow uniformity.

[0272] The fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number flowing through the conduits or conduits in the fiber opening zone 400 may be in the range of about 2,100 to about 6,000, about 3,000 to about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number of the flow through the conduits or conduits is at least 2,500, at least about 3,500, or at least about 4,000.

[0273] The fiber opening zone 400 can be implemented in a pipe or conduit containing a mixing device inserted into a conduit or conduit. This device can include an in-line mixing device. The in-line mixing device can be a static mixer without moving parts. In another embodiment, the in-line mixing device includes a moving part. Non-limitingly, this element is a mechanical device for imparting more mixing energy to the heated multi-component fiber slurry 301 than the mixing energy achieved through flow through a conduit. This device can be inserted at the beginning of a conduit section serving as the fiber opening zone, at the end of a conduit section, or anywhere within the conduit flow path.

[0274] An open fiber slurry stream 401 comprising non-aqueous polymer microfibers, water, and a water-dispersible sulfonyl polyester can be fed to a primary solid-liquid separation zone 500 to produce a microfiber agglomerate stream 503 comprising microfibers and a first mother liquor stream 501. In one embodiment, the first mother liquor stream 501 comprises water and a water-dispersible sulfonyl polyester.

[0275] The percentage by weight of solids in the open microfiber slurry 401 may be in the range of about 0.1% by weight to about 20% by weight, about 0.3% by weight to about 10% by weight, about 0.3% by weight to about 5% by weight, or about 0.3% by weight to about 2.5% by weight.

[0276] The weight percentage of solids in the microfiber product stream 503 can range from about 10 wt% to about 65 wt%, from about 15 wt% to about 50 wt%, from about 25 wt% to about 45 wt%, or from about 30 wt% to about 40 wt%.

[0277] The separation of the microfiber product stream 503 from the opened microfiber slurry 401 can be achieved by any method known in the art. In one embodiment, a washing liquid stream 103 containing water is fed to a primary solid-liquid separation zone 500. The washing liquid stream 103 can be used to wash the microfiber product stream and / or the filter cloth media in the first solid-liquid separation zone 500 to produce a washing liquid stream 502. Before entering the first solid-liquid separation zone 500, a portion (up to 100% by weight) of the washing liquid stream 502 may be combined with the opened microfiber slurry 401. Up to 100% by weight of the washing liquid stream 502 may be fed to a second solid-liquid separation zone 600. The washing liquid stream 502 may contain microfibers. In one embodiment, the weight of the microfiber material that has passed through the filter media with an opening of up to 2000 micrometers in the primary solid-liquid separation zone 500 is approximately 1 to 2 g / cm³. 2 Filtration area. In other embodiments of the invention, the filter pores in the filter medium in the primary solid-liquid separation zone 500 may be in the range of about 43 micrometers to 3000 micrometers, about 100 micrometers to 2000 micrometers, or about 500 micrometers to about 2000 micrometers.

[0278] In the primary solid-liquid separation zone 500, the separation of the microfiber product stream from the opened microfiber slurry can be achieved by one or more solid-liquid separation devices. The separation in the primary solid-liquid separation zone 500 can be accomplished by one or more solid-liquid separation devices operating in an intermittent and / or continuous manner. Suitable solid-liquid separation devices in the primary solid-liquid separation zone 500 may include, but are not limited to, at least one of the following: a porous basket centrifuge, a continuous vacuum belt filter, an intermittent vacuum suction filter, an intermittent porous settling tank, a double-net dewatering device, a continuous horizontal belt filter with a compression zone, a non-vibrating inclined screen device with a wedge-shaped mesh filter medium, a continuous vacuum drum filter, a dewatering conveyor belt, etc.

[0279] In one embodiment, the primary solid-liquid separation zone 500 includes a double-net dewatering device, wherein an opened microfiber slurry 401 is fed into a tapered gap between a pair of traveling filter cloths moving in the same direction. In a first region of the double-net dewatering device, water is drained from the opened microfiber slurry 401 due to gravity and each narrowing gap between the two moving filter cloths. In a downstream region of the double-net dewatering device, the two filter cloths and the microfiber material between them are compressed once or multiple times to mechanically reduce the moisture content in the microfiber material. In one embodiment, mechanical dewatering is achieved by passing the two filter cloths and the contained microfiber material through at least one set of rollers, which apply compressive force to the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is achieved by passing the two filter cloths and the microfiber material between at least one set of pressure rollers.

[0280] In other embodiments of the invention, the force applied by mechanical dewatering for each set of pressure rollers can range from about 25 to about 300 psi for the filter media width, from about 50 to about 200 psi for the filter media width, or from about 70 to about 125 psi for the filter media width. As the two filter cloths separate and disperse in the solids discharge zone of the device, the microfiber product stream 503 is discharged from the dual-web dewatering unit. The thickness of the discharged microfiber material can range from about 0.2 inches to about 1.5 inches, from about 0.3 inches to about 1.25 inches, or from about 0.4 inches to about 1 inch. In one embodiment, a wash stream containing water is continuously applied to the filter media. In another embodiment, a wash stream containing water is periodically applied to the filter media.

[0281] In another embodiment, the primary solid-liquid separation zone 500 includes a belt filter device as shown in FIG. 7, comprising a gravity drainage zone and a pressure dewatering zone. The opened microfiber slurry 401 is fed into a tapered gap between a pair of movable filter cloths traveling in the same direction, first passing through the gravity drainage zone, and then through a zone comprising... Figure 6b The diagram shows a complex roller arrangement in a pressure dewatering or pressing zone. As the belt is fed through these rollers, water is squeezed out of the solids. When the belt passes the last pair of rollers in the process, the filter cloth separates and the solids exit the belt filter device.

[0282] In another embodiment of the invention, at least a portion of the water contained in a first mother liquor stream 501 comprising water and a water-dispersible sulfopolyester polymer is recovered and recycled. The first mother liquor stream 501 can be recycled to a primary solid-liquid separation zone 500. Depending on the efficiency of the primary liquid separation zone in the removal of non-water-dispersible microfibers, the first mother liquor stream 501 can be recycled to a fiber opening zone 400 or fed to a heat exchange zone 800 before being fed to zone 400. The first mother liquor stream 501 may contain a small amount of solids comprising non-water-dispersible polymer microfibers due to leakage and cloth washing. In one embodiment, the weight of the non-water-dispersible polymer microfiber material that leaks through a filter medium with openings of up to 2000 micrometers in the primary solid-liquid separation zone is about 1 to about 2 g / cm³. 2 Filtration area. It is desirable to minimize non-aqueous polymer microfiber solids in the first mother liquor stream 501 before sending the feed stream 501 to the primary concentration zone 700 and the heat exchange zone 800, where non-aqueous polymer microfiber solids can collect and accumulate in these areas, negatively impacting their function.

[0283] The secondary solid-liquid separation zone 600 can be used to remove at least a portion of the non-aqueous dispersible polymer microfiber solids present in the first mother liquor stream 501 to generate a second wet filter cake stream 602 containing non-aqueous dispersible microfibers and a second mother liquor stream 601 containing water and a water-dispersible sulfopolyester.

[0284] In one embodiment, a second mother liquor stream 601 may be fed to a primary concentration zone 700 and / or a heat exchange zone 800, wherein the weight percentage of the second mother liquor stream 601 fed to the primary concentration zone 700 may be 0% to 100%, and the remainder of the stream may be fed to the heat exchange zone 800. The second mother liquor stream 601 may be recycled to a fiber opening zone 400 or fed to the heat exchange zone 800 before being fed to zone 400. The amount of water-dispersible sulfopolyester in the second mother liquor stream fed to the fiber opening zone 400 may be from about 0.01 wt% to about 7 wt%, or from about 0.1 wt% to about 7 wt%, or from about 0.2 wt% to about 5 wt%, or from about 0.3 wt% to about 3 wt%, based on the weight percentage of the second mother liquor stream.

[0285] Any portion of the second mother liquor 601 sent to the primary concentration zone undergoes a separation process to generate a primary recycled water stream 703 and a primary polymer concentrate stream 702 enriched with water-dispersible sulfonyl polyester, wherein the weight percentage of water-dispersible sulfonyl polyester in the primary polymer concentrate stream 702 can be from about 5% to about 85%, from about 10% to about 65%, or from about 15% to about 45%. The primary recycled water stream 703 can be recycled to the fiber opening zone 400 or the heat exchange zone 800 before being sent to zone 400. The amount of water-dispersible sulfonyl polyester in the second mother liquor stream sent to the fiber opening zone 400 can be from about 0.01% to about 7% based on the weight percentage of the second mother liquor stream, or from about 0.1% to about 7% based on the weight percentage of the second mother liquor stream, from about 0.2% to about 5% based on the weight percentage of the second mother liquor stream, or from about 0.3% to about 3% based on the weight percentage of the second mother liquor stream.

[0286] In the primary concentration zone 700, water can be removed from the second mother liquor stream 601 by any method known in the art to produce a primary polymer concentrate stream 702. In one embodiment, water removal includes evaporation by evaporating water in a batch or continuous evaporation apparatus. For example, at least one thin-film evaporator can be used for this application. In another embodiment, membrane technology incorporating nanofiltration media can be used to generate the primary polymer concentrate stream 702. In another embodiment, a method incorporating an extraction apparatus can be used to extract the water-dispersible polymer from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. It should be understood that any combination of evaporation, membrane, and extraction steps can be used to separate the water-dispersible sulfonyl polyester from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. The primary polymer concentrate stream 702 can then exit the process.

[0287] In one embodiment, a primary polymer concentrate stream 702 may be fed to a secondary concentration zone 900 to generate a molten polymer stream 903 comprising a water-dispersible sulfonyl polyester (wherein the polymer comprises approximately 95% to approximately 100% by weight) and a vapor stream 902 comprising water. In one embodiment, 903 comprises a water-dispersible sulfonyl polyester. Suitable equipment for the secondary concentration zone 900 includes any equipment known in the art capable of feeding an aqueous dispersion of a water-dispersible polymer and generating a 95% to 100% water-dispersible polymer stream 903. This embodiment involves feeding an aqueous dispersion of a water-dispersible sulfonyl polyester polymer into the secondary concentration zone 902. The temperature of the feed stream is typically below 100°C.

[0288] In one embodiment, the secondary concentration zone 900 includes at least one device characterized by a jacketed shell containing a rotating conveyor screw, wherein the conveyor screw is heated with a heat transfer fluid or steam and includes conveying and high-shear mixing elements. The jacket or shell is vented to allow steam to escape. The jacket or shell can be partitioned to set different temperature setpoints along the length of the device. During continuous operation, the primary polymer concentrate stream 702, containing water and a water-dispersible sulfopolyester, is continuously fed into the secondary concentration zone 900. Within this device, during steady-state operation, clumps exit in at least three distinct and different forms. The clumps initially exist in the device as an aqueous dispersion of the water-dispersible sulfopolyester polymer. As the aqueous dispersion of the sulfopolyester polymer passes through the device, water evaporates due to the heat from the jacket and the internal screw. When sufficient water evaporates, the clump transforms into a second form, a viscous plug contained at a temperature lower than the melt temperature of the sulfopolyester polymer. The aqueous dispersion cannot flow through this viscous plug and is confined to the first aqueous dispersion region of the device. Due to the heat from the jacket, the internally heated screw, and the combined shear forces attributable to the highly viscous plug agglomerates, virtually all the water present at this location evaporates and the temperature rises until it reaches the melt temperature of the sulfonyl polyester, producing a third and final physical form of agglomerates in the apparatus, comprising molten sulfonyl polyester polymer. This molten sulfonyl polyester polymer then exits the apparatus through an extrusion die and is typically cooled and granulated by any means known in the art. It should be understood that the apparatus for the aforementioned secondary concentration zone 900 can also be operated intermittently, wherein the three agglomerate physical forms appear sequentially throughout the entire length of the apparatus but at different times, beginning with an aqueous dispersion, followed by viscous plug agglomerates, and finally the sulfonyl polyester melt.

[0289] In one embodiment, the vapor generated in the secondary concentration zone 900 can be condensed and sent to the heat exchange zone 800, discharged, and / or sent to the wash stream 103. In another embodiment, a condensed vapor stream 902 containing water vapor can be sent to the heat exchange zone 800 to provide at least a portion of the energy required to reach the temperature of the generated feed stream 801. The molten polymer stream 903 of the water-dispersible polymer containing sulfonated polyester in the molten phase can be cooled and pelletized by any method known in the art.

[0290] Impurities can enter the method and concentrate in the recovered and recycled water. The concentration of impurities in the second mother liquor 601 and the primary recovered water stream 701 can be controlled to acceptable levels using one or more scavenging streams (603 and 701). In one embodiment, a portion of the second mother liquor stream 601 can be separated and removed from the process. In one embodiment, a portion of the primary recovered water stream 701 can be separated and removed from the process.

[0291] Two-step method for producing short-cut microfibers

[0292] In such Figure 3a In another embodiment of the invention shown, a method for producing a microfiber product stream is provided. The method includes:

[0293] (A) In a fiber slurry zone 200, chopped multicomponent fibers 101 having a length of less than 25 mm are contacted with a treated aqueous stream 103 to produce a chopped multicomponent fiber slurry 201; wherein the chopped multicomponent fibers 101 comprise at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonyl polyester; and wherein the treated aqueous stream 103 is at a temperature below 40°C; wherein the multicomponent fibers comprise at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol% of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein The diol comprises 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all of the stated molar percentages are based on a sum of all acidic and hydroxyl repeating units equal to 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) residues of diethylene glycol, wherein the sulfonyl polyester comprises residues of diethylene glycol and 1,4-cyclohexanediethanol. The alcohol residues have a molar ratio of less than 1:1, wherein the sulfonyl polyester contains substantially equimolar proportions of acid molar repeating units (100 mol percent) and hydroxyl molar repeating units (100 mol percent), and wherein all said molar percentages are based on a sum of all acid and hydroxyl molar repeating units equal to 200 mol percent; and (iii) a sulfonyl polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonyl monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57 °C, wherein the sulfonyl polyester contains substantially equimolar proportions of acid molar repeating units (100 mol percent) and hydroxyl molar repeating units (100 mol percent). (a) molar percentage) and hydroxyl molar repeating units (100 molar percentage), and wherein all said molar percentages are based on the sum of all acid and hydroxyl molar repeating units equaling 200 molar percentages; (b) contacting chopped multicomponent fiber slurry 201 with heated aqueous stream 801 in fiber opening zone 400 to remove a portion of the water-dispersible sulfonyl polyester to produce opened microfiber slurry 401; wherein the opened microfiber slurry comprises non-aqueous polymer microfibers, water-dispersible sulfonyl polyester and water; and (c) feeding the opened microfiber slurry 401 to primary solid-liquid separation zone 500 to produce microfiber product stream 503 and first mother liquor stream 501; wherein the first mother liquor stream 501 comprises water and water-dispersible sulfonyl polyester.

[0294] In this embodiment of the invention, such as Figure 4 The mixing zone 300 and the fiber opening zone 400 shown are combined into a single unit operation in the opening treatment zone 1100. The opening treatment zone 1100 includes the fiber slurry zone 200 and the fiber opening zone 400.

[0295] The treated aquifer stream 103 used in this method can be generated by sending the aquifer stream 102 to the aquifer treatment zone 1000 to produce the treated aquifer stream 103. The aquifer stream contains water. In embodiments of the invention, the concentration of monovalent metal cations in the treated aquifer stream 103 can be less than about 1000 ppm by weight, less than about 500 ppm by weight, less than about 100 ppm by weight, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from the aquifer stream 102 is a function of the aquifer treatment zone 1000. In other embodiments of the invention, the concentration of divalent and polyvalent cations is less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of the stream 103 can be in the range of groundwater temperature to about 40°C.

[0296] The treatment of the aqueous stream 102 in the aqueous treatment zone 1000 can be performed in any manner known in the art. In one embodiment, the aqueous treatment zone 1000 includes a distillation apparatus in which water vapor is generated and condensed to produce a treated aqueous stream 103. In another embodiment, water is fed to a reverse osmosis membrane capable of separating monovalent and divalent metal cations from water to produce a treated aqueous stream 103. In yet another embodiment, water is fed to an ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal cations. In still another embodiment, water may be fed to a commercial water softening unit to produce a treated aqueous stream 103 having an acceptable low concentration of divalent and polyvalent metal cations. It should be understood that any combination of these water treatment options can be employed to achieve the desired treated water characteristics.

[0297] The treated aqueous stream 103 can be sent to any location in the process where it is needed. In one embodiment, a portion of the stream 103 is sent to the primary solid-liquid separation zone 500 to be used as a washing solution and / or a washing solution for the solids contained in the primary solid-liquid separation zone 500.

[0298] In one embodiment, at least a portion of the treated aqueous stream 103 is fed to a heat exchange zone 800. In another embodiment, at least a portion of the treated aqueous stream 103 is fed to a fiber sizing zone 200. In yet another embodiment, at least a portion of the treated aqueous stream 103 is fed to both the heat exchange zone 800 and the fiber sizing zone 200. One function of the heat exchange zone 800 is to generate a heated aqueous stream 801 at a specific and controlled temperature.

[0299] In one embodiment, the feed stream that can be fed into the heat exchange zone 800 is a treated aqueous feed stream 103 and a second mother liquor stream 601. In another embodiment, the feed stream that can be fed into the heat exchange zone 800 includes a treated aqueous feed stream 103, a primary recycled water stream 703, a first mother liquor stream 501, and a second mother liquor stream 601.

[0300] Any device known in the art for controlling the temperature of flow 801 can be used, including but not limited to any heat exchanger with steam for providing a portion of the required energy, any heat exchanger with a heat transfer fluid for providing a portion of the required energy, any heat exchanger with an electric heating element for providing a portion of the required energy, and any container or tank with direct steam injection in which steam condenses and the condensate mixes with water supplied to heat exchange zone 800. The multicomponent fiber flow 90 is fed to fiber cutting zone 100 to produce chopped multicomponent fiber flow 101. The multicomponent fiber can be any multicomponent structure known in the art. The multicomponent fiber comprises a water-dispersible sulfonated polyester and a non-water-dispersible polymer, as previously discussed in this disclosure.

[0301] Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the diced multicomponent fiber stream 101. In one embodiment, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or less than 2.5 mm.

[0302] A stream of diced multicomponent fibers 101 and a portion of a treated aqueous stream 103 are fed to a fiber slurry zone 200 to produce a diced multicomponent fiber slurry 201 containing water and diced multicomponent fibers. In one embodiment, the percentage by weight of the diced multicomponent fibers in the diced multicomponent fiber slurry 201 may range from about 35% by weight to about 1% by weight, from about 25% by weight to about 1% by weight, from about 15% by weight to about 1% by weight, or from about 7% by weight to about 1% by weight.

[0303] The temperature of the segmented multicomponent fiber slurry 201 can be in the range of about 5 degrees Celsius to about 45 degrees Celsius, about 10 degrees Celsius to about 35 degrees Celsius, or about 10 degrees Celsius to about 25 degrees Celsius. In one embodiment, the fiber slurry zone 200 includes a tank with stirring sufficient to generate a segmented multicomponent fiber suspension in a continuous aqueous phase.

[0304] In the fiber pulping zone 200, any apparatus known in the art suitable for mixing solids with water and maintaining the resulting suspension of diced multi-component fibers in a continuous phase may be used. The fiber pulping zone 200 may include batch or continuous mixing devices that operate in continuous or batch mode. Suitable apparatus for the fiber pulping zone 200 includes, but is not limited to, a hydrapulper, a continuously stirred tank reactor, and a stirred tank that operates in batch mode.

[0305] The diced multicomponent fiber slurry 201 can then be fed to the fiber opening zone 400. One function of the fiber opening zone 400 is to separate the water-dispersible polymer from the diced multicomponent fibers, such that at least a portion of the non-water-dispersible polymer microfibers are separated from the diced multicomponent fibers and suspended in the opened microfiber slurry 401. In another embodiment of the invention, about 50% to about 100% by weight of the non-water-dispersible polymer microfibers contained in the diced multicomponent fiber slurry 201 become suspended in the opened microfiber slurry 401 as non-water-dispersible polymer microfibers and are no longer part of the diced multicomponent fibers. In other embodiments, about 75% to about 100% by weight, about 90% to about 100% by weight, or about 95% to about 100% by weight of the non-water-dispersible polymer microfibers contained in the diced multicomponent fiber stream 201 become suspended in the opened microfiber slurry 401 as non-water-dispersible polymer microfibers and are no longer part of the diced multicomponent fibers.

[0306] The diameter or denier of the initial segmented multicomponent fibers in flow 201 affects the degree of separation between the water-dispersible sulfonyl polyester and the segmented multicomponent fibers in the fiber opening zone 400. Typical multicomponent fiber types typically have diameters ranging from about 12 micrometers to about 20 micrometers. Available multicomponent fibers can have larger initial diameters, approximately 40 micrometers or larger. The time required to separate the desired amount of water-dispersible sulfonyl polyester from the segmented multicomponent fibers increases with the diameter of the segmented multicomponent fibers in flow 201.

[0307] The residence time, temperature, and shear force in the fiber opening zone 400 also affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. Conditions affecting the opening process in the fiber opening zone 400 include residence time, slurry temperature, and shear force, wherein the water temperature, residence time in the fiber opening zone 400, and the range of applied shear force are determined by the need to separate the water-dispersible sulfonyl polyester from the initial multicomponent fibers to a level sufficient to cause the non-water-dispersible polymer microfibers to separate and suspend in the continuous aqueous phase of the opened microfiber slurry 401.

[0308] The residence time, temperature, and shear force in the fiber opening zone 400 affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. The temperature of the fiber opening zone 400 can range from about 55°C to about 100°C, from about 60°C to about 90°C, or from about 65°C to about 80°C. The residence time in the fiber opening zone 400 can range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber opening zone 400 to maintain a suspension of the diced non-aqueous polymer microfibers, minimizing the sedimentation of the diced microfibers. In other embodiments of the invention, the mass per unit time of the segmented non-aqueous dispersible microfibers settling in the fiber opening zone 400 is less than about 5% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, less than about 3% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, or less than about 1% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the fiber opening zone 400.

[0309] Fiber opening in the fiber opening zone 400 can be performed in any equipment that allows for acceptable residence time, temperature, and mixing. Examples of suitable equipment include, but are not limited to, stirred batch reactors and continuous stirred tank reactors (such as...). Figure 6b and 6c (as shown) and pipes with sufficient flow to minimize the settling of solids from the slurry (such as...). Figure 6a (As shown). An example of a unit operation that completes fiber opening in zone 400 is a plug flow reactor, in which heated multi-component fiber slurry 301 is fed into a plug flow device in zone 400, typically a circular pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the packed volume within the device by the volumetric flow rate within the device. The mass velocity within the device is defined by dividing the cross-sectional area of ​​the flow channel by the volumetric flow rate of the liquid through the device.

[0310] In other embodiments of the invention, the fiber opening zone 400 may include a conduit or duct, wherein the mass velocity of the flow in the conduit may be in the range of 0.1 ft / s to about 20 ft / s, 0.2 ft / s to about 10 ft / s, or about 0.5 ft / s to about 5 ft / s. For the flow of fluid or slurry in a conduit or duct, the Reynolds number Re is a dimensionless number that can be used to describe turbulence or motion of fluid eddies that are irregular in direction and time. For flow in a conduit or duct, the Reynolds number is generally defined as:

[0311]

[0312] in:

[0313] ·D H L is the hydraulic diameter of the pipe (m).

[0314] Q is the volumetric flow rate (m³ / s). 3 / s).

[0315] • A is the cross-sectional area of ​​the pipe (m²) 2 ).

[0316] •v is the average velocity of an object relative to a fluid (SI unit: m / s).

[0317] μ is the dynamic viscosity of the fluid (Pa·s or N·s / m³). 2 Or kg / (m·s)).

[0318] ·v is the kinematic viscosity (ν=μ / ρ)(m 2 / s).

[0319] ρ is the density of the fluid (kg / m³) 3 ).

[0320] For flow in a pipe of diameter D, experimental observations show that for fully expanded flow, when Re D Laminar flow occurs when Re < 2000, while when Re D Turbulence occurs at temperatures above 4000. In the range of 2300 to 4000, both laminar and turbulent flow (“transitional” flow) are possible, depending on other factors such as pipe roughness and flow uniformity.

[0321] The fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number flowing through the conduits or conduits in the fiber opening zone 400 may be in the range of about 2,100 to about 6,000, about 3,000 to about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number of the flow through the conduits or conduits is at least 2,500, at least about 3,500, or at least about 4,000.

[0322] The fiber opening zone 400 can be implemented in a pipe or conduit containing a mixing device inserted into a conduit or conduit. This device can include an in-line mixing device. The in-line mixing device can be a static mixer without moving parts. In another embodiment, the in-line mixing device includes a moving part. Non-limitingly, this element is a mechanical device for imparting more mixing energy to the heated multi-component fiber slurry 301 than the mixing energy achieved through flow through a conduit. This device can be inserted at the beginning of a conduit section serving as the fiber opening zone, at the end of a conduit section, or anywhere within the conduit flow path.

[0323] An open fiber slurry stream 401 comprising non-aqueous polymer microfibers, water, and a water-dispersible sulfonyl polyester can be fed to a primary solid-liquid separation zone 500 to produce a microfiber agglomerate stream 503 comprising microfibers and a first mother liquor stream 501. In one embodiment, the first mother liquor stream 501 comprises water and a water-dispersible sulfonyl polyester.

[0324] The percentage by weight of solids in the open microfiber slurry 401 may be in the range of about 0.1% by weight to about 20% by weight, about 0.3% by weight to about 10% by weight, about 0.3% by weight to about 5% by weight, or about 0.3% by weight to about 2.5% by weight.

[0325] The weight percentage of solids in the microfiber product stream 503 can range from about 10 wt% to about 65 wt%, from about 15 wt% to about 50 wt%, from about 25 wt% to about 45 wt%, or from about 30 wt% to about 40 wt%.

[0326] The separation of the microfiber product stream 503 from the opened microfiber slurry 401 can be achieved by any method known in the art. In one embodiment, a washing liquid stream 103 containing water is fed to a primary solid-liquid separation zone 500. The washing liquid stream 103 can be used to wash the microfiber product stream and / or the filter cloth media in the first solid-liquid separation zone 500 to produce a washing liquid stream 502. Before entering the first solid-liquid separation zone 500, a portion (up to 100% by weight) of the washing liquid stream 502 may be combined with the opened microfiber slurry 401. Up to 100% by weight of the washing liquid stream 502 may be fed to a second solid-liquid separation zone 600. The washing liquid stream 502 may contain microfibers. In one embodiment, the weight of the microfiber material that has passed through the filter media with an opening of up to 2000 micrometers in the primary solid-liquid separation zone 500 is approximately 1 to 2 g / cm³. 2 Filtration area. In other embodiments of the invention, the filter pores in the filter medium in the primary solid-liquid separation zone 500 may be in the range of about 43 micrometers to 3000 micrometers, about 100 micrometers to 2000 micrometers, or about 500 micrometers to about 2000 micrometers.

[0327] In the primary solid-liquid separation zone 500, the separation of the microfiber product stream from the opened microfiber slurry can be achieved by one or more solid-liquid separation devices. The separation in the primary solid-liquid separation zone 500 can be accomplished by one or more solid-liquid separation devices operating in an intermittent and / or continuous manner. Suitable solid-liquid separation devices in the primary solid-liquid separation zone 500 may include, but are not limited to, at least one of the following: a porous basket centrifuge, a continuous vacuum belt filter, an intermittent vacuum suction filter, an intermittent porous settling tank, a double-net dewatering device, a continuous horizontal belt filter with a compression zone, a non-vibrating inclined screen device with a wedge-shaped mesh filter medium, a continuous vacuum drum filter, a dewatering conveyor belt, etc.

[0328] In one embodiment, the primary solid-liquid separation zone 500 includes a double-net dewatering device, wherein an opened microfiber slurry 401 is fed into a tapered gap between a pair of traveling filter cloths moving in the same direction. In a first region of the double-net dewatering device, water is drained from the opened microfiber slurry 401 due to gravity and each narrowing gap between the two moving filter cloths. In a downstream region of the double-net dewatering device, the two filter cloths and the microfiber material between them are compressed once or multiple times to mechanically reduce the moisture content in the microfiber material. In one embodiment, mechanical dewatering is achieved by passing the two filter cloths and the contained microfiber material through at least one set of rollers, which apply compressive force to the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is achieved by passing the two filter cloths and the microfiber material between at least one set of pressure rollers.

[0329] In other embodiments of the invention, the force applied by mechanical dewatering for each set of pressure rollers can range from about 25 to about 300 psi for the filter media width, from about 50 to about 200 psi for the filter media width, or from about 70 to about 125 psi for the filter media width. As the two filter cloths separate and disperse in the solids discharge zone of the device, the microfiber product stream 503 is discharged from the dual-web dewatering unit. The thickness of the discharged microfiber material can range from about 0.2 inches to about 1.5 inches, from about 0.3 inches to about 1.25 inches, or from about 0.4 inches to about 1 inch. In one embodiment, a wash stream containing water is continuously applied to the filter media. In another embodiment, a wash stream containing water is periodically applied to the filter media.

[0330] In another embodiment, the primary solid-liquid separation zone 500 includes a belt filter device as shown in FIG. 7, comprising a gravity drainage zone and a pressure dewatering zone. The opened microfiber slurry 401 is fed into a tapered gap between a pair of movable filter cloths traveling in the same direction, first passing through the gravity drainage zone, and then through a zone comprising... Figure 6b The diagram shows a complex roller arrangement in a pressure dewatering or pressing zone. As the belt is fed through these rollers, water is squeezed out of the solids. As the belt passes through the last pair of rollers in this process, the filter cloth is separated, and the solids exit the belt filter.

[0331] In another embodiment of the invention, at least a portion of the water contained in a first mother liquor stream 501 comprising water and a water-dispersible sulfopolyester polymer is recovered and recycled. The first mother liquor stream 501 can be recycled to a primary solid-liquid separation zone 500. Depending on the efficiency of the primary liquid separation zone in the removal of non-water-dispersible microfibers, the first mother liquor stream 501 can be recycled to a fiber slurry zone 200, a fiber opening zone 400, or a heat exchange zone 800 before being sent to zones 200 and / or 400. The first mother liquor stream 501 may contain a small amount of solids comprising non-water-dispersible polymer microfibers due to leakage and cloth washing. In one embodiment, the weight of the non-water-dispersible polymer microfiber material that has leaked through a filter medium with an opening of up to 2000 micrometers in the primary solid-liquid separation zone is about 1 to about 2 g / cm³. 2 Filtration area. It is desirable to minimize non-aqueous polymer microfiber solids in the first mother liquor stream 501 before sending the feed stream 501 to the primary concentration zone 700 and the heat exchange zone 800, where non-aqueous polymer microfiber solids can collect and accumulate in these areas, negatively impacting their function.

[0332] The secondary solid-liquid separation zone 600 can be used to remove at least a portion of the non-aqueous dispersible polymer microfiber solids present in the first mother liquor stream 501 to generate a second wet filter cake stream 602 containing non-aqueous dispersible microfibers and a second mother liquor stream 601 containing water and a water-dispersible sulfopolyester.

[0333] In one embodiment, a second mother liquor stream 601 may be fed to a primary concentration zone 700 and / or a heat exchange zone 800, wherein the weight percentage of the second mother liquor stream 601 fed to the primary concentration zone 700 may be 0% to 100%, and the remainder of the stream may be fed to the heat exchange zone 800. Before being fed to zones 200 and / or 400, the second mother liquor stream 601 may be recycled to the fiber slurry zone 200, the fiber opening zone 400, or the heat exchange zone 800. The amount of water-dispersible sulfonyl polyester in the second mother liquor stream fed to the fiber opening zone 400 may be from about 0.01 wt% to about 7 wt%, or from about 0.1 wt% to about 7 wt%, or from about 0.2 wt% to about 5 wt%, or from about 0.3 wt% to about 3 wt%.

[0334] Any portion of the second mother liquor 601 sent to the primary concentration zone undergoes a separation process to generate a primary recycled water stream 703 and a primary polymer concentrate stream 702 enriched with water-dispersible sulfonyl polyester, wherein the weight percentage of water-dispersible sulfonyl polyester in the primary polymer concentrate stream 702 can be from about 5% to about 85%, from about 10% to about 65% by weight, or from about 15% to about 45% by weight. The primary recycled water stream 703 may be recycled to the fiber slurry zone 200, the fiber opening zone 400, or the heat exchange zone 800 before being sent to zones 200 and / or 400. The amount of water-dispersible sulfonyl polyester in the second mother liquor stream sent to the fiber opening zone 400 can be from about 0.01% to about 7% by weight, or from about 0.1% to about 7% by weight, from about 0.2% to about 5% by weight, or from about 0.3% to about 3% by weight of the second mother liquor stream.

[0335] In the primary concentration zone 700, water can be removed from the second mother liquor stream 601 by any method known in the art to produce a primary polymer concentrate stream 702. In one embodiment, water removal includes evaporation by evaporating water in a batch or continuous evaporation apparatus. For example, at least one thin-film evaporator can be used for this application. In another embodiment, membrane technology incorporating nanofiltration media can be used to generate the primary polymer concentrate stream 702. In another embodiment, a method incorporating an extraction apparatus can be used to extract the water-dispersible polymer from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. It should be understood that any combination of evaporation, membrane, and extraction steps can be used to separate the water-dispersible sulfonyl polyester from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. The primary polymer concentrate stream 702 can then exit the process.

[0336] In one embodiment, a primary polymer concentrate stream 702 may be fed to a secondary concentration zone 900 to generate a molten polymer stream 903 comprising a water-dispersible sulfonyl polyester (wherein the polymer comprises approximately 95% to approximately 100% by weight) and a vapor stream 902 comprising water. In one embodiment, 903 comprises a water-dispersible sulfonyl polyester. Suitable equipment for the secondary concentration zone 900 includes any equipment known in the art capable of feeding an aqueous dispersion of a water-dispersible polymer and generating a 95% to 100% water-dispersible polymer stream 903. This embodiment involves feeding an aqueous dispersion of a water-dispersible sulfonyl polyester polymer into the secondary concentration zone 902. The temperature of the feed stream is typically below 100°C.

[0337] In one embodiment, the secondary concentration zone 900 includes at least one device characterized by a jacketed shell containing a rotating conveyor screw, wherein the conveyor screw is heated with a heat transfer fluid or steam and includes conveying and high-shear mixing elements. The jacket or shell is vented to allow steam to escape. The jacket or shell can be partitioned to set different temperature setpoints along the length of the device. During continuous operation, the primary polymer concentrate stream 702, containing water and a water-dispersible sulfopolyester, is continuously fed into the secondary concentration zone 900. Within this device, during steady-state operation, clumps exit in at least three distinct and different forms. The clumps initially exist in the device as an aqueous dispersion of the water-dispersible sulfopolyester polymer. As the aqueous dispersion of the sulfopolyester polymer passes through the device, water evaporates due to the heat from the jacket and the internal screw. When sufficient water evaporates, the clump transforms into a second form, a viscous plug contained at a temperature lower than the melt temperature of the sulfopolyester polymer. The aqueous dispersion cannot flow through this viscous plug and is confined to the first aqueous dispersion region of the device. Due to the heat from the jacket, the internally heated screw, and the combined shear forces attributable to the highly viscous plug agglomerates, virtually all the water present at this location evaporates and the temperature rises until it reaches the melt temperature of the sulfonyl polyester, producing a third and final physical form of agglomerates in the apparatus, comprising molten sulfonyl polyester polymer. This molten sulfonyl polyester polymer then exits the apparatus through an extrusion die and is typically cooled and granulated by any means known in the art. It should be understood that the apparatus for the aforementioned secondary concentration zone 900 can also be operated intermittently, wherein the three agglomerate physical forms appear sequentially throughout the entire length of the apparatus but at different times, beginning with an aqueous dispersion, followed by viscous plug agglomerates, and finally the sulfonyl polyester melt.

[0338] In one embodiment, the vapor generated in the secondary concentration zone 900 can be condensed and sent to the heat exchange zone 800, discharged, and / or sent to the wash stream 103. In another embodiment, a condensed vapor stream 902 containing water vapor can be sent to the heat exchange zone 800 to provide at least a portion of the energy required to reach the temperature of the generated feed stream 801. The molten polymer stream 903 of the water-dispersible polymer containing sulfonated polyester in the molten phase can be cooled and pelletized by any method known in the art.

[0339] Impurities can enter the method and concentrate in the recovered and recycled water. The concentration of impurities in the second mother liquor 601 and the primary recovered water stream 701 can be controlled to acceptable levels using one or more scavenging streams (603 and 701). In one embodiment, a portion of the second mother liquor stream 601 can be separated and removed from the process. In one embodiment, a portion of the primary recovered water stream 701 can be separated and removed from the process.

[0340] In such Figure 3bIn another embodiment of the invention shown, a method for producing a microfiber product stream is provided. The method includes: (A) contacting chopped multicomponent fibers 101 having a length of less than 25 mm with a treated aqueous stream 801 in a mixing zone to produce a chopped multicomponent fiber slurry 301; wherein the chopped multicomponent fibers 101 comprise at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible polymer immiscible with the water-dispersible sulfonyl polyester; and wherein the heated aqueous stream 801 is at a temperature of 40°C or higher; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; and (c) The sulfonyl polyester comprises residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar amounts of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; (ii) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 mol percent of at least one sulfonyl monomer; (c) residues of 1,4-cyclohexanediethanol; and (d) a diethylene glycol. The residues, wherein the sulfonated polyester comprises residues of diethylene glycol and residues of 1,4-cyclohexanediethanol in a molar ratio of less than 1:1, wherein the sulfonated polyester contains substantially equimolar proportions of acidic repeating units (100 mol percent) and hydroxyl repeating units (100 mol percent), and wherein all said molar percentages are based on the sum of all acidic and hydroxyl repeating units being equal to 200 mol percent; and (iii) a sulfonated polyester comprising: (a) residues of isophthalic acid; (b) residues of terephthalic acid; (c) residues of at least one sulfonated monomer; (d) residues of 1,4-cyclohexanediethanol; and (e) residues of diethylene glycol; (a) An alcohol residue, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C, wherein the sulfonyl polyester contains substantially equimolar proportions of acid moiety repeating units (100 mol percent) and hydroxyl moiety repeating units (100 mol percent), and wherein all said moiety percentages are based on the sum of all acid and hydroxyl moiety repeating units being equal to 200 mol percent; (b) A chopped multicomponent fiber slurry 301 and an optional heated aqueous stream 801 are fed to a fiber opening zone 400 to remove a portion of the water-dispersible sulfonyl polyester to produce an opened microfiber slurry 401; wherein the opened microfiber slurry 401 comprises non-water-dispersible polymer microfibers, water-dispersible sulfonyl polyester, and water;(C) The opened microfiber slurry 401 is fed to the primary solid-liquid separation zone 500 to generate a microfiber product stream 503 and a first mother liquor stream 501; wherein the first mother liquor stream 501 comprises water and a water-dispersible sulfonyl polyester.

[0341] In such Figure 3b In this embodiment of the invention shown, the fiber slurry zone 200 and the fiber mixing zone 300 are combined into a single unit operation within the opening treatment zone 1100. The opening treatment zone 1100 includes the mixing zone 200 and the fiber opening zone 400.

[0342] The treated aquifer stream 103 used in this method can be generated by sending the aquifer stream 102 to the aquifer treatment zone 1000 to produce the treated aquifer stream 103. The aquifer stream contains water. In embodiments of the invention, the concentration of monovalent metal cations in the treated aquifer stream 103 can be less than about 1000 ppm by weight, less than about 500 ppm by weight, less than about 100 ppm by weight, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from the aquifer stream 102 is a function of the aquifer treatment zone 1000. In other embodiments of the invention, the concentration of divalent and polyvalent cations is less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of the stream 103 can be in the range of groundwater temperature to about 40°C.

[0343] The treatment of the aqueous stream 102 in the aqueous treatment zone 1000 can be performed in any manner known in the art. In one embodiment, the aqueous treatment zone 1000 includes a distillation apparatus in which water vapor is generated and condensed to produce a treated aqueous stream 103. In another embodiment, water is fed to a reverse osmosis membrane capable of separating monovalent and divalent metal cations from water to produce a treated aqueous stream 103. In yet another embodiment, water is fed to an ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal cations. In still another embodiment, water may be fed to a commercial water softening unit to produce a treated aqueous stream 103 having an acceptable low concentration of divalent and polyvalent metal cations. It should be understood that any combination of these water treatment options can be employed to achieve the desired treated water characteristics.

[0344] The treated aqueous stream 103 can be sent to any location in the process where it is needed. In one embodiment, a portion of the stream 103 is sent to the primary solid-liquid separation zone 500 to be used as a washing solution and / or a washing solution for the solids contained in the primary solid-liquid separation zone 500.

[0345] In one embodiment, at least a portion of the treated aqueous stream 103 is fed to a heat exchange zone 800. In another embodiment, at least a portion of the treated aqueous stream 103 is fed to a mixing zone 300. In yet another embodiment, at least a portion of the treated aqueous stream 103 is fed to both the heat exchange zone 800 and the mixing zone 300. One function of the heat exchange zone 800 is to generate a heated aqueous stream 801 at a specific and controlled temperature.

[0346] In one embodiment, the feed stream that can be fed into the heat exchange zone 800 is a treated aqueous feed stream 103 and a second mother liquor stream 601. In another embodiment, the feed stream that can be fed into the heat exchange zone 800 includes a treated aqueous feed stream 103, a primary recycled water stream 703, a first mother liquor stream 501, and a second mother liquor stream 601.

[0347] Any device known in the art for controlling the temperature of flow 801 can be used, including but not limited to any heat exchanger with steam for providing a portion of the required energy, any heat exchanger with a heat transfer fluid for providing a portion of the required energy, any heat exchanger with an electric heating element for providing a portion of the required energy, and any container or tank with direct steam injection in which steam condenses and the condensate mixes with water supplied to heat exchange zone 800. The multicomponent fiber flow 90 is fed to fiber cutting zone 100 to produce chopped multicomponent fiber flow 101. The multicomponent fiber can be any multicomponent structure known in the art. The multicomponent fiber comprises a water-dispersible sulfonated polyester and a non-water-dispersible polymer, as previously discussed in this disclosure.

[0348] Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the diced multicomponent fiber stream 101. In one embodiment, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the diced fibers in the diced multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or less than 2.5 mm.

[0349] The diced multi-component fiber stream 101 and a portion of the heated water-containing material stream 801 are fed to the mixing zone 300 to produce a heated multi-component fiber slurry 301 containing water and diced multi-component fibers.

[0350] The temperature of the heated multicomponent fiber slurry 301 affects the separation of the water-dispersible sulfopolyester portion of the diced multicomponent fiber from the non-water-dispersible polymer portion of the diced multicomponent fiber in the fiber opening zone 400. In other embodiments of the invention, the temperature of the heated multicomponent fiber slurry 301 can be from about 55 degrees Celsius to about 100 degrees Celsius, from about 60 degrees Celsius to about 90 degrees Celsius, or from about 65 degrees Celsius to about 80 degrees Celsius.

[0351] The weight percentage of diced multicomponent fibers in the heated multicomponent fiber slurry 301 can be controlled. In other embodiments, the weight percentage of diced multicomponent fibers in the heated multicomponent fiber slurry 301 can range from about 10% to about 0.1% by weight, from about 5% to about 0.2% by weight, from about 3% to about 0.3% by weight, or from about 2% to about 0.4% by weight.

[0352] Any apparatus known in the art capable of mixing a heated, moist feed stream 801 with diced multi-component fibers 101 can be used in the mixing zone 300. Suitable apparatus includes continuous and intermittent mixing devices. In one embodiment, a suitable mixing device for the mixing zone 300 includes a tank and an agitator. In another embodiment, a suitable mixing device includes a pipe or conduit.

[0353] In other embodiments, a suitable mixing device in mixing zone 300 includes a pipe or conduit with a diameter such that the velocity in the conduit is sufficient to mix the diced multicomponent fiber slurry 201 and the heated aqueous stream 801, wherein less than about 2% by weight, less than about 1% by weight, or less than about 0.5% by weight of the diced multicomponent material entering the conduit per minute settles out and accumulates in the conduit.

[0354] The heated multi-component fiber slurry 301 can then be fed to the fiber opening zone 400. One function of the fiber opening zone 400 is to separate the aqueous polymer from the diced multi-component fibers, such that at least a portion of the non-aqueous polymer microfibers are separated from the diced multi-component fibers and suspended in the opened microfiber slurry 401. In another embodiment of the invention, about 50% to about 100% by weight of the non-aqueous polymer microfibers contained in the diced multi-component fiber slurry 201 become suspended in the opened microfiber slurry 401 as non-aqueous polymer microfibers and are no longer part of the diced multi-component fibers. In other embodiments, about 75% to about 100% by weight, about 90% to about 100% by weight, or about 95% to about 100% by weight of the non-aqueous polymer microfibers contained in the diced multi-component fiber stream 201 become suspended in the opened microfiber slurry 401 as non-aqueous polymer microfibers and are no longer part of the diced multi-component fibers.

[0355] The diameter or denier of the initial segmented multicomponent fibers in flow 201 affects the degree of separation between the water-dispersible sulfonyl polyester and the segmented multicomponent fibers in the fiber opening zone 400. Typical multicomponent fiber types typically have diameters ranging from about 12 micrometers to about 20 micrometers. Available multicomponent fibers can have larger initial diameters, approximately 40 micrometers or larger. The time required to separate the desired amount of water-dispersible sulfonyl polyester from the segmented multicomponent fibers increases with the diameter of the segmented multicomponent fibers in flow 201.

[0356] The residence time, temperature, and shear force in the fiber opening zone 400 also affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. Conditions affecting the opening process in the fiber opening zone 400 include residence time, slurry temperature, and shear force, wherein the water temperature, residence time in the fiber opening zone 400, and the range of applied shear force are determined by the need to separate the water-dispersible sulfonyl polyester from the initial multicomponent fibers to a level sufficient to cause the non-water-dispersible polymer microfibers to separate and suspend in the continuous aqueous phase of the opened microfiber slurry 401.

[0357] The residence time, temperature, and shear force in the fiber opening zone 400 affect the degree of separation of the water-dispersible sulfonyl polyester from the diced multicomponent fibers. The temperature of the fiber opening zone 400 can range from about 55°C to about 100°C, from about 60°C to about 90°C, or from about 65°C to about 80°C. The residence time in the fiber opening zone 400 can range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber opening zone 400 to maintain a suspension of the diced non-aqueous polymer microfibers, minimizing the sedimentation of the diced microfibers. In other embodiments of the invention, the mass per unit time of the segmented non-aqueous dispersible microfibers settling in the fiber opening zone 400 is less than about 5% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, less than about 3% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the zone 400, or less than about 1% of the mass per unit time of the segmented non-aqueous dispersible polymer microfibers entering the fiber opening zone 400.

[0358] Fiber opening in zone 400 can be performed in any apparatus that allows for acceptable residence time, temperature, and mixing. Examples of suitable apparatus include, but are not limited to, stirred batch reactors, continuous stirred tank reactors (as shown in Figures 6B and 6C), and pipes with sufficient flow rates to minimize solid settling from the slurry (as shown in Figure 6A). An example of a unit operation for performing fiber opening in zone 400 is a plug flow reactor, in which heated multi-component fiber slurry 301 is fed to a plug flow device in zone 400, typically a circular pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the fill volume within the device by the volumetric flow rate within the device. The mass velocity within the device is defined by dividing the cross-sectional area of ​​the flow channel by the volumetric flow rate of the liquid through the device.

[0359] In other embodiments of the invention, the fiber opening zone 400 may include a conduit or duct, wherein the mass velocity of the flow in the conduit may be in the range of 0.1 ft / s to about 20 ft / s, 0.2 ft / s to about 10 ft / s, or about 0.5 ft / s to about 5 ft / s. For the flow of fluid or slurry in a conduit or duct, the Reynolds number Re is a dimensionless number that can be used to describe turbulence or motion of fluid eddies that are irregular in direction and time. For flow in a conduit or duct, the Reynolds number is generally defined as:

[0360]

[0361] in:

[0362] ·D H L is the hydraulic diameter of the pipe (m).

[0363] Q is the volumetric flow rate (m³ / s). 3 / s).

[0364] • A is the cross-sectional area of ​​the pipe (m²) 2 ).

[0365] •v is the average velocity of an object relative to a fluid (SI unit: m / s).

[0366] μ is the dynamic viscosity of the fluid (Pa·s or N·s / m³). 2 Or kg / (m·s)).

[0367] ·v is the kinematic viscosity (ν=μ / ρ)(m 2 / s).

[0368] ρ is the density of the fluid (kg / m³) 3 ).

[0369] For flow in a pipe of diameter D, experimental observations show that for fully expanded flow, when Re DLaminar flow occurs when Re < 2000, while when Re D Turbulence occurs at temperatures above 4000. In the range of 2300 to 4000, both laminar and turbulent flow (“transitional” flow) are possible, depending on other factors such as pipe roughness and flow uniformity.

[0370] The fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number flowing through the conduits or conduits in the fiber opening zone 400 may be in the range of about 2,100 to about 6,000, about 3,000 to about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber opening zone 400 may include conduits or conduits to facilitate the opening process, and the Reynolds number of the flow through the conduits or conduits is at least 2,500, at least about 3,500, or at least about 4,000.

[0371] The fiber opening zone 400 can be implemented in a pipe or conduit containing a mixing device inserted into a conduit or conduit. This device can include an in-line mixing device. The in-line mixing device can be a static mixer without moving parts. In another embodiment, the in-line mixing device includes a moving part. Non-limitingly, this element is a mechanical device for imparting more mixing energy to the heated multi-component fiber slurry 301 than the mixing energy achieved through flow through a conduit. This device can be inserted at the beginning of a conduit section serving as the fiber opening zone, at the end of a conduit section, or anywhere within the conduit flow path.

[0372] An open fiber slurry stream 401 comprising non-aqueous polymer microfibers, water, and a water-dispersible sulfonyl polyester can be fed to a primary solid-liquid separation zone 500 to produce a microfiber agglomerate stream 503 comprising microfibers and a first mother liquor stream 501. In one embodiment, the first mother liquor stream 501 comprises water and a water-dispersible sulfonyl polyester.

[0373] The percentage by weight of solids in the open microfiber slurry 401 may be in the range of about 0.1% by weight to about 20% by weight, about 0.3% by weight to about 10% by weight, about 0.3% by weight to about 5% by weight, or about 0.3% by weight to about 2.5% by weight.

[0374] The weight percentage of solids in the microfiber product stream 503 can range from about 10 wt% to about 65 wt%, from about 15 wt% to about 50 wt%, from about 25 wt% to about 45 wt%, or from about 30 wt% to about 40 wt%.

[0375] The separation of the microfiber product stream 503 from the opened microfiber slurry 401 can be achieved by any method known in the art. In one embodiment, a washing liquid stream 103 containing water is fed to a primary solid-liquid separation zone 500. The washing liquid stream 103 can be used to wash the microfiber product stream and / or the filter cloth media in the first solid-liquid separation zone 500 to produce a washing liquid stream 502. Before entering the first solid-liquid separation zone 500, a portion (up to 100% by weight) of the washing liquid stream 502 may be combined with the opened microfiber slurry 401. Up to 100% by weight of the washing liquid stream 502 may be fed to a second solid-liquid separation zone 600. The washing liquid stream 502 may contain microfibers. In one embodiment, the weight of the microfiber material that has passed through the filter media with an opening of up to 2000 micrometers in the primary solid-liquid separation zone 500 is approximately 1 to 2 g / cm³. 2 Filtration area. In other embodiments of the invention, the filter pores in the filter medium in the primary solid-liquid separation zone 500 may be in the range of about 43 micrometers to 3000 micrometers, about 100 micrometers to 2000 micrometers, or about 500 micrometers to about 2000 micrometers.

[0376] In the primary solid-liquid separation zone 500, the separation of the microfiber product stream from the opened microfiber slurry can be achieved by one or more solid-liquid separation devices. The separation in the primary solid-liquid separation zone 500 can be accomplished by one or more solid-liquid separation devices operating in an intermittent and / or continuous manner. Suitable solid-liquid separation devices in the primary solid-liquid separation zone 500 may include, but are not limited to, at least one of the following: a porous basket centrifuge, a continuous vacuum belt filter, an intermittent vacuum suction filter, an intermittent porous settling tank, a double-net dewatering device, a continuous horizontal belt filter with a compression zone, a non-vibrating inclined screen device with a wedge-shaped mesh filter medium, a continuous vacuum drum filter, a dewatering conveyor belt, etc.

[0377] In one embodiment, the primary solid-liquid separation zone 500 includes a double-net dewatering device, wherein an opened microfiber slurry 401 is fed into a tapered gap between a pair of traveling filter cloths moving in the same direction. In a first region of the double-net dewatering device, water is drained from the opened microfiber slurry 401 due to gravity and each narrowing gap between the two moving filter cloths. In a downstream region of the double-net dewatering device, the two filter cloths and the microfiber material between them are compressed once or multiple times to mechanically reduce the moisture content in the microfiber material. In one embodiment, mechanical dewatering is achieved by passing the two filter cloths and the contained microfiber material through at least one set of rollers, which apply compressive force to the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is achieved by passing the two filter cloths and the microfiber material between at least one pressure roller and a stationary surface.

[0378] In other embodiments of the invention, the force applied by mechanical dewatering can range from about 25 to about 300 psi for the filter media width, from about 50 to about 200 psi for the filter media width, or from about 70 to about 125 psi for the filter media width. As the two filter cloths separate and disperse in the solids discharge zone of the device, the microfiber product stream 503 is discharged from the dual-net dewatering device. The thickness of the discharged microfiber material can range from about 0.2 inches to about 1.5 inches, from about 0.3 inches to about 1.25 inches, or from about 0.4 inches to about 1 inch. In one embodiment, a wash stream containing water is continuously applied to the filter media. In another embodiment, a wash stream containing water is periodically applied to the filter media.

[0379] In another embodiment, the primary solid-liquid separation zone 500 includes a belt filter device as shown in FIG. 7, comprising a gravity drainage zone and a pressure dewatering zone. The opened microfiber slurry 401 is fed into a tapered gap between a pair of movable filter cloths traveling in the same direction, first passing through the gravity drainage zone, and then through a zone comprising... Figure 6b The diagram shows a complex roller arrangement in a pressure dewatering or pressing zone. As the belt is fed through these rollers, water is squeezed out of the solids. As the belt passes through the last pair of rollers in this process, the filter cloth is separated, and the solids exit the belt filter.

[0380] In another embodiment of the invention, at least a portion of the water contained in a first mother liquor stream 501 comprising water and a water-dispersible sulfopolyester polymer is recovered and recycled. The first mother liquor stream 501 can be recycled to a primary solid-liquid separation zone 500. Depending on the efficiency of the primary liquid separation zone in the removal of non-water-dispersible microfibers, the first mother liquor stream 501 can be recycled to a mixing zone 300, a fiber opening zone 400, or a heat exchange zone 800 before being sent to zones 200, 300, and / or 400. The first mother liquor stream 501 may contain a small amount of solids comprising non-water-dispersible polymer microfibers due to leakage and cloth washing. In one embodiment, the weight of the non-water-dispersible polymer microfiber material that leaks through a filter medium with an opening of up to 2000 micrometers in the primary solid-liquid separation zone is about 1 to about 2 g / cm³. 2 Filtration area. It is desirable to minimize non-aqueous polymer microfiber solids in the first mother liquor stream 501 before sending the feed stream 501 to the primary concentration zone 700 and the heat exchange zone 800, where non-aqueous polymer microfiber solids can collect and accumulate in these areas, negatively impacting their function.

[0381] The secondary solid-liquid separation zone 600 can be used to remove at least a portion of the non-aqueous dispersible polymer microfiber solids present in the first mother liquor stream 501 to generate a second wet filter cake stream 602 containing non-aqueous dispersible microfibers and a second mother liquor stream 601 containing water and a water-dispersible sulfopolyester.

[0382] In one embodiment, a second mother liquor stream 601 may be fed to a primary concentration zone 700 and / or a heat exchange zone 800, wherein the weight percentage of the second mother liquor stream 601 fed to the primary concentration zone 700 may be 0% to 100%, and the remainder of the stream may be fed to the heat exchange zone 800. Before being fed to zones 200, 300, and / or 400, the second mother liquor stream 601 may be recycled to a fiber slurry zone 200, a mixing zone 300, a fiber opening zone 400, or a heat exchange zone 800. The amount of water-dispersible sulfopolyester in the second mother liquor stream fed to the fiber opening zone 400 may be from about 0.01% by weight to about 7% by weight, or from about 0.1% by weight to about 7% by weight, or from about 0.2% by weight to about 5% by weight, or from about 0.3% by weight to about 3% by weight.

[0383] Any portion of the second mother liquor 601 sent to the primary concentration zone undergoes a separation process to generate a primary recovered water stream 703 and a primary polymer concentrate stream 702 enriched with water-dispersible sulfonyl polyester, wherein the weight percentage of water-dispersible sulfonyl polyester in the primary polymer concentrate stream 702 can be from about 5% to about 85%, from about 10% to about 65% by weight, or from about 15% to about 45% by weight. The primary recovered water stream 703 may be a mixing zone 300, a fiber opening zone 400, or a heat exchange zone 800 before being sent to zones 200, 300, and / or 400. The amount of water-dispersible sulfonyl polyester in the second mother liquor stream sent to the fiber opening zone 400 can be from about 0.01% to about 7% by weight, or from about 0.1% to about 7% by weight, from about 0.2% to about 5% by weight, or from about 0.3% to about 3% by weight of the second mother liquor stream.

[0384] In the primary concentration zone 700, water can be removed from the second mother liquor stream 601 by any method known in the art to produce a primary polymer concentrate stream 702. In one embodiment, water removal includes evaporation by evaporating water in a batch or continuous evaporation apparatus. For example, at least one thin-film evaporator can be used for this application. In another embodiment, membrane technology incorporating nanofiltration media can be used to generate the primary polymer concentrate stream 702. In another embodiment, a method incorporating an extraction apparatus can be used to extract the water-dispersible polymer from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. It should be understood that any combination of evaporation, membrane, and extraction steps can be used to separate the water-dispersible sulfonyl polyester from the second mother liquor stream 601 and generate the primary polymer concentrate stream 702. The primary polymer concentrate stream 702 can then exit the process.

[0385] In one embodiment, a primary polymer concentrate stream 702 may be fed to a secondary concentration zone 900 to generate a molten polymer stream 903 comprising a water-dispersible sulfonyl polyester (wherein the polymer comprises approximately 95% to approximately 100% by weight) and a vapor stream 902 comprising water. In one embodiment, 903 comprises a water-dispersible sulfonyl polyester. Suitable equipment for the secondary concentration zone 900 includes any equipment known in the art capable of feeding an aqueous dispersion of a water-dispersible polymer and generating a 95% to 100% water-dispersible polymer stream 903. This embodiment involves feeding an aqueous dispersion of a water-dispersible sulfonyl polyester polymer into the secondary concentration zone 902. The temperature of the feed stream is typically below 100°C.

[0386] In one embodiment, the secondary concentration zone 900 includes at least one device characterized by a jacketed shell containing a rotating conveyor screw, wherein the conveyor screw is heated with a heat transfer fluid or steam and includes conveying and high-shear mixing elements. The jacket or shell is vented to allow steam to escape. The jacket or shell can be partitioned to set different temperature setpoints along the length of the device. During continuous operation, the primary polymer concentrate stream 702, containing water and a water-dispersible sulfopolyester, is continuously fed into the secondary concentration zone 900. Within this device, during steady-state operation, clumps exit in at least three distinct and different forms. The clumps initially exist in the device as an aqueous dispersion of the water-dispersible sulfopolyester polymer. As the aqueous dispersion of the sulfopolyester polymer passes through the device, water evaporates due to the heat from the jacket and the internal screw. When sufficient water evaporates, the clump transforms into a second form, a viscous plug contained at a temperature lower than the melt temperature of the sulfopolyester polymer. The aqueous dispersion cannot flow through this viscous plug and is confined to the first aqueous dispersion region of the device. Due to the heat from the jacket, the internally heated screw, and the combined shear forces attributable to the highly viscous plug agglomerates, virtually all the water present at this location evaporates and the temperature rises until it reaches the melt temperature of the sulfonyl polyester, producing a third and final physical form of agglomerates in the apparatus, comprising molten sulfonyl polyester polymer. This molten sulfonyl polyester polymer then exits the apparatus through an extrusion die and is typically cooled and granulated by any means known in the art. It should be understood that the apparatus for the aforementioned secondary concentration zone 900 can also be operated intermittently, wherein the three agglomerate physical forms appear sequentially throughout the entire length of the apparatus but at different times, beginning with an aqueous dispersion, followed by viscous plug agglomerates, and finally the sulfonyl polyester melt.

[0387] In one embodiment, the vapor generated in the secondary concentration zone 900 can be condensed and sent to the heat exchange zone 800, discharged, and / or sent to the wash stream 103. In another embodiment, a condensed vapor stream 902 containing water vapor can be sent to the heat exchange zone 800 to provide at least a portion of the energy required to reach the temperature of the generated feed stream 801. The molten polymer stream 903 of the water-dispersible polymer containing sulfonated polyester in the molten phase can be cooled and pelletized by any method known in the art.

[0388] Impurities can enter the method and concentrate in the recovered and recycled water. The concentration of impurities in the second mother liquor 601 and the primary recovered water stream 701 can be controlled to acceptable levels using one or more scavenging streams (603 and 701). In one embodiment, a portion of the second mother liquor stream 601 can be separated and removed from the process. In one embodiment, a portion of the primary recovered water stream 701 can be separated and removed from the process.

[0389] Three-step method for producing short-cut microfibers

[0390] In such Figure 4In another embodiment of the invention shown, a method for producing a microfiber product stream is provided. The method includes: (A) contacting chopped multicomponent fibers 101 having a length of less than 25 mm with a treated aqueous stream 103 in a fiber slurry zone 200 to produce a chopped multicomponent fiber slurry 201; wherein the chopped multicomponent fibers 101 comprise at least one water-dispersible sulfonyl polyester and at least one non-water-dispersible synthetic polymer immiscible with the water-dispersible sulfonyl polyester; and wherein the treated aqueous stream 103 is at a temperature below 40°C; wherein the chopped multicomponent fibers comprise at least one water-dispersible sulfonyl polyester selected from: (i) a sulfonyl polyester comprising: (a) residues of one or more dicarboxylic acids; (b) residues of at least 10 molar percentage of at least one sulfonyl monomer; (c) res...

Claims

1. A water-dispersible sulfonyl polyester, said sulfonyl polyester comprising: (a) One or more dicarboxylic acid residues; (b) at least 14 molar percentage of residues of at least one sulfonyl monomer; and (c) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol. The sulfonyl polyester described therein exhibits a glass transition temperature of at least 57°C. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and All the molar percentages mentioned herein are based on the sum of all repeating units of the acid and hydroxyl groups being equal to 200 molar percentages. The sulfonated polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue.

2. A water-dispersible sulfonyl polyester, said sulfonyl polyester comprising: (a) One or more dicarboxylic acid residues; (b) at least 14 molar percentage of residues of at least one sulfonyl monomer; (c) Residues of 1,4-cyclohexanediethanol; and (d) Diethylene glycol residues, The sulfonyl polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and All the molar percentages mentioned herein are based on the sum of all repeating units of the acid and hydroxyl groups being equal to 200 molar percentages.

3. A water-dispersible sulfonyl polyester, said sulfonyl polyester comprising: (a) Residues of isophthalic acid; (b) Residues of terephthalic acid; (c) at least 14 molar percentage of residues of at least one sulfonyl monomer; (d) Residues of 1,4-cyclohexanediethanol; and (e) Diethylene glycol residues, The sulfonyl polyester described therein exhibits a glass transition temperature of at least 57°C. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and All the molar percentages mentioned herein are based on the sum of all repeating units of the acid and hydroxyl groups being equal to 200 molar percentages. The sulfonated polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue.

4. The water-dispersible sulfonyl polyester of claim 2, wherein the sulfonyl polyester exhibits a glass transition temperature of at least 57°C.

5. The water-dispersible sulfonyl polyester according to claim 1, 2 or 3, wherein the sulfonyl polyester comprises a specific logarithmic viscosity of at least 0.1 dL / g.

6. The water-dispersible sulfonated polyester according to claim 1, 2 or 3, wherein the sulfonated polyester does not contain any ethylene glycol.

7. The water-dispersible sulfonyl polyester according to claim 1, 2 or 3, wherein the sulfonyl polyester comprises two diols, wherein the diols are composed of 1,4-cyclohexanediethanol and diethylene glycol.

8. The water-dispersible sulfonyl polyester according to claim 1, 2 or 3, wherein the sulfonyl polyester comprises at least 20 mol percent and no more than 99 mol percent of the residues of the 1,4-cyclohexanediethanol.

9. The water-dispersible sulfonyl polyester according to claim 1, 2 or 3, wherein when the sulfonyl polyester is added to pure water at 90°C under constant stirring for at least 5 minutes, the sulfonyl polyester is capable of forming an aqueous dispersion comprising at least 1 weight percentage of the sulfonyl polyester.

10. The water-dispersible sulfonated polyester according to claim 1, 2 or 3, wherein the sulfonated monomer comprises sulfoisophthalic acid.

11. The water-dispersible sulfonated polyester of claim 3, wherein the sulfonated polyester comprises at least 14 mol percent and less than 40 mol percent of the sulfonated monomer.

12. The water-dispersible sulfonyl polyester according to claim 1 or 2, wherein the residues of one or more dicarboxylic acids are derived from terephthalic acid, isophthalic acid, or a combination thereof.

13. A woven article comprising a sulfonated polyester according to claim 1, 2 or 3.

14. A nonwoven article comprising a sulfonated polyester according to claim 1, 2 or 3.

15. An article comprising a sulfonated polyester according to claim 1, 2 or 3.

16. A multi-component fiber having a shaped cross-section, the multi-component fiber comprising: (a) A water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) at least 14 molar percentages of residues of at least one sulfonyl monomer, and (iii) residues of two or more diols, wherein said diols include 1,4-cyclohexanediethanol and diethylene glycol. The sulfonyl polyester described therein exhibits a glass transition temperature of at least 57°C. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and Wherein all the stated molar percentages are based on the sum of all acid and hydroxyl partial repeating units equaling 200 molar percentages; and (b) One or more domains comprising one or more non-aqueous dispersible polymers immiscible with the sulfonyl polyester. The sulfonated polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue.

17. A multi-component fiber having a shaped cross-section, the multi-component fiber comprising: (a) A water-dispersible sulfonyl polyester comprising: (i) residues of one or more dicarboxylic acids, (ii) at least 14 molar percentage of residues of at least one sulfonyl monomer, (iii) Residues of 1,4-cyclohexanediethanol, and (iv) Diethylene glycol residues, The sulfonyl polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and Wherein all the stated molar percentages are based on the sum of all acid and hydroxyl partial repeating units equaling 200 molar percentages; and (b) One or more domains comprising one or more non-aqueous dispersible polymers that are immiscible with the sulfonyl polyester.

18. A multi-component fiber having a shaped cross-section, the multi-component fiber comprising: (a) A water-dispersible sulfonyl polyester comprising: (i) Residues of isophthalic acid, (ii) Residues of terephthalic acid, (iii) at least 14 molar percentage of residues of at least one sulfonyl monomer, (iv) Residues of 1,4-cyclohexanediethanol; and (v) Diethylene glycol residues, The sulfonyl polyester described therein exhibits a glass transition temperature of at least 57°C. The sulfonyl polyester contains substantially equimolar amounts of acid-repeating units and hydroxyl-repeating units, and Wherein all the stated molar percentages are based on the sum of all acid and hydroxyl partial repeating units equaling 200 molar percentages; and (b) One or more domains comprising one or more non-aqueous dispersible polymers, The sulfonated polyester comprises a diethylene glycol residue in a molar ratio of less than 0.25:1 to the 1,4-cyclohexanediethanol residue.

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