Absorbent hygiene products comprising superabsorbent polymers derived in part from recycled resources and methods of producing the same

Abstract

The present invention discloses an absorbent polymer (AHP) comprising a topsheet, a backsheet joined to the topsheet, an absorbent core disposed between the topsheet and the backsheet, and a poly(acrylic acid)-based superabsorbent polymer (SAP) derived in part from recycled resources. The SAP exhibits defined values ​​for saline flow conductivity and absorbency against pressure. The present invention also discloses a method for preparing the AHP.

Description

Technical Field

[0001] The present invention relates to an absorbent hygiene product (AHP) comprising a superabsorbent polymer (cycloSAP) obtained by polymerizing acrylic acid in the presence of poly(acrylic acid) (PAA). The PAA is prepared from recycled superabsorbent polymer (rSAP) via a degradation process and is essentially a non-crosslinked, linear or slightly branched molecule. CycloSAP has the same properties as pristine SAP (i.e., SAP polymerized from 100% acrylic acid; vSAP). Finally, the rSAP is separated from the recycled AHP (rAHP) and then degraded into PAA. Background Art

[0002] Many consumers demand and expect companies to produce products that contain recycled materials, which are materials derived from recycled resources and are optionally processed and purified so that they can be reused. In some cases, consumers hesitate to buy products made from only limited non-renewable resources (such as oil, natural gas, and coal). Other consumers may have a negative perception of products that do not contain recycled materials, believing them to be not environmentally friendly.

[0003] Recycling AHPs (i.e., baby diapers, feminine protection pads, and adult incontinence pads) is beneficial to the environment and is necessary for many consumer product companies to achieve their sustainability goals. These goals involve using 100% recycled materials and achieving zero landfill for consumer and manufacturing waste. Beyond these goals, successful recycling benefits the environment, stimulates the economy, improves human health and water quality, and provides needed energy for consumers in developing regions of the world.

[0004] The main component of AHP is usually superabsorbent polymer (SAP), while other components are binders, cellulose fibers, polyethylene, polypropylene, and polyester. SAP is a water-absorbing, water-swellable, and water-insoluble powdered solid, which is usually a cross-linked and partially neutralized homopolymer of glacial acrylic acid. SAP has an exceptionally high ability to absorb aqueous liquids (such as contaminated water or urine). Approximately 97% of SAP produced today is used in AHP applications, while the remaining 3% is used in other applications such as agricultural or horticultural water retainers and industrial waterproofing agents.

[0005] Recycling AHP involves collecting the recycled AHP, cleaning it of any soiling that accumulates during its use, and separating the various components into recycled material streams. More specifically, the recycled SAP material stream can be used in applications that require less than the AHP (because the properties of the recycled SAP are inferior compared to virgin SAP; for example, agricultural or horticultural water retainers and industrial water repellents) and / or can be converted into PAA. This PAA can then be used as a feed material for a variety of applications. For example, PAA can be: 1) used as is in applications such as water treatment or corrosion inhibition; 2) esterified and then used in adhesives, coatings, etc.; and 3) blended with acrylic acid when the acrylic acid is polymerized and crosslinked to form SAP. The first two groups of applications are part of efforts to recycle SAP into other products by replacing virgin acrylic acid-based compounds with compounds derived from recycled SAP, while the latter group of applications is part of the SAP circular economy (i.e., recycling SAP back into SAP). In all cases, the goal is to achieve the same properties as the virgin material.

[0006] Non-limiting examples of processes for producing a purified and separated spent SAP material stream from recovered AHP are disclosed and claimed in U.S. Patents 9,095,853 and 9,156,034, both assigned to Fater SpA, headquartered in Pescara, Italy. Non-limiting examples of procedures for producing SAP from glacial acrylic acid and a cross-linking agent are disclosed in U.S. Patent 8,383,746, assigned to Nippon Shokubai Co., Ltd, headquartered in Osaka, Japan, and U.S. Patent 9,822,203, assigned to BASF SE, headquartered in Ludwigshafen, Germany.

[0007] Therefore, there is a need to recycle AHP and its main component, which is SAP. For SAP recycling, it is desirable to degrade the recycled SAP to poly(acrylic acid) (PAA) within a short timeframe, using low energy and electricity per unit mass of SAP, and under mild conditions, such as room temperature, to avoid PAA decarboxylation. The low energy requirement per unit mass of SAP stems from the fact that recycling SAP and degrading it to PAA is beneficial only if the energy consumed during the conversion of SAP to PAA is less than the energy used to produce fossil-derived acrylic acid (petro-AA) from propylene (approximately 50 MJ / kg AA). PAA made from recycled SAP can then be incorporated back into virgin SAP (thereby increasing its recycled content and supporting a circular economy for SAP) and / or derived into materials for other applications such as adhesives, coatings, water treatment, fabric care, and the like. Furthermore, it would be desirable to provide an AHP comprising SAP partially derived from recycled resources, wherein the superabsorbent polymer has the same properties as the virgin SAP. Ideally, it would be desirable to provide an AHP comprising SAP partially derived from recycled resources and communicating relevant environmental information. Summary of the Invention

[0008] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer is provided. The method comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP into a material comprising poly(acrylic acid) (PAA); and (iii) polymerizing acrylic acid in the presence of the PAA to form the SAP exhibiting an absorbency against pressure (AAP) of at least about 15 g / g; b) combining the SAP with AHP components including a topsheet and a backsheet to define the AHP; c) disposing the AHP in a package; and d) communicating environmental information to the consumer to convey that the AHP comprises materials derived from recycled resources.

[0009] In another embodiment of the present invention, a method for providing AHP to a consumer is provided. The method comprises: a) providing a superabsorbent polymer (SAP) prepared by the following steps: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP into a material comprising poly(acrylic acid) (PAA) by treatment in an extensional flow device; and (iii) polymerizing the acrylic acid in the presence of the PAA to form a superabsorbent polymer exhibiting an absorption against pressure (AAP) of at least about 15 g / g and an absorption against pressure of at least about 30×10 -7 cm 3.s / g of the SAP; b) combining the SAP with an AHP component including a top sheet and a back sheet to define the AHP; c) arranging the AHP in a package; and d) conveying environmental information to the consumer to convey that the AHP contains materials derived from recycled resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A is a plan view of an exemplary AHP in the form of a diaper in a flat, uncontracted state.

[0011] Figure 1B It is cut along the lateral centerline Figure 1A Cross-sectional view of a diaper.

[0012] Figures 2A to 2B is a perspective view of a package including AHP.

[0013] Figures 3A to 3F are illustrations of several suitable embodiments of icons that convey reduced petrochemical dependence and / or environmental friendliness.

[0014] Figure 4 is a partial cross-sectional side view of a suitable permeability measurement system for conducting saline flow conductivity testing.

[0015] Figure 5 is a cross-sectional side view of a piston / cylinder assembly used for conducting saline flow conductivity testing.

[0016] Figure 6 is applicable to Figure 5 A top view of the piston head of the piston / cylinder assembly is shown.

[0017] Figure 7 yes Figure 5 Cross-sectional side view of the piston / cylinder assembly placed on the sintered disk for the swelling phase. DETAILED DESCRIPTION

[0018] I. Definition

[0019] As used herein, the term "disposable" refers to an item that is intended to be discarded after a limited number of uses, typically a single use (i.e., the original AHP as a whole is not intended to be laundered or reused as an AHP, but certain materials or portions of the AHP may be recycled, reused, or composted). For example, some disposable AHPs can be temporarily restored to substantially full functionality through the use of removable / replaceable components, but the AHP is still considered disposable because the entire AHP is intended to be discarded after a limited number of uses.

[0020] As used herein, the term "absorbent hygiene product (AHP)" refers to a product that absorbs and contains body exudates, and more specifically refers to a product that is placed against or adjacent to the wearer's body to absorb and contain various exudates discharged from the body. Exemplary AHPs include diapers, training pants, pull-on diapers (i.e., diapers with pre-formed waist and leg openings such as shown in U.S. Patent 6,120,487), refastenable diapers or pant diapers, incontinence briefs and underwear, diaper holders and liners, feminine hygiene underwear such as sanitary pads (e.g., such as disclosed in U.S. Patents 4,425,130, 4,687,478, 5,267,992 and 5,733,274), absorbent pads, etc. AHPs can be disposable or can include reusable or restorable portions.

[0021] As used herein, the terms "proximal" and "distal" refer to the location of an element relatively close to or away from the longitudinal or lateral centerline of a structure, respectively (e.g., relative to the same longitudinal centerline, the proximal edge of a longitudinally extending element is located closer to the longitudinal centerline than the distal edge of the same element).

[0022] As used herein, the terms "body-facing" and "garment-facing" refer to the relative position of an element or the relative position of a surface of an element or a group of elements, respectively. "Body-facing" means that the element or surface is closer to the wearer during wear than some other elements or surfaces. "Garment-facing" means that the element or surface is farther away from the wearer during wear than some other elements or surfaces (i.e., the element or surface is closer to the wearer's clothing, which may be worn over an AHP).

[0023] As used herein, the term "superabsorbent polymer (SAP)" refers to a polymer capable of absorbing at least ten times its dry weight in a 0.9% saline solution at 25° C. SAP absorbs fluid via an osmotic mechanism to form a gel, commonly referred to as a "hydrogel," and is used interchangeably with the term "hydrogel."

[0024] As used herein, the term "longitudinal direction" refers to the direction extending substantially perpendicularly from one waist edge to the opposite waist edge of the product and generally parallel to the largest linear dimension of the product. Directions within 45 degrees of the longitudinal direction are considered "longitudinal."

[0025] As used herein, the term "lateral" refers to a direction extending from one longitudinal edge of a product to the opposite longitudinal edge and generally at right angles to the longitudinal direction. Directions within 45 degrees of the lateral direction are considered "lateral."

[0026] As used herein, the term "disposed" means that an element is positioned at a specific location or position.

[0027] As used herein, the term "joined" refers to configurations in which an element is directly secured to another element by attaching the element directly to the other element, as well as configurations in which an element is indirectly secured to another element by attaching the element to an intermediate member that is in turn attached to the other element.

[0028] As used herein, the term "film" refers to a sheet-like material in which the length and width of the material greatly exceed the thickness of the material. Typically, a film has a thickness of about 0.5 mm or less.

[0029] As used herein, the term "impermeable" generally refers to a barrier to penetration below 0.14 lb / in. 2 A product and / or component that is impermeable to fluids through the entire Z-dimensional thickness of the product at a pressure of 0.5 lb / in. or less. Preferably, the impermeable product or component is impermeable to fluids at a pressure of 0.5 lb / in. 2 More preferably, the impermeable product or component is impermeable to fluids at a pressure of 1.0 lb / in. 2 Impermeability is determined by the test method in accordance with EDANA 120.1-18 or INDAIST 80.6.

[0030] As used herein, the terms "ductility" and "extensible" mean that the width or length of a component in a relaxed state can be extended or increased by at least about 10% without breaking or rupturing when subjected to a stretching force.

[0031] As used herein, the terms "elastic," "elastomer," and "elastomeric" refer to a material that is typically capable of extending to a strain of at least 50% without breaking or rupturing, and that is capable of recovering substantially to its original dimensions after the deforming force is removed.

[0032] As used herein, the term "elastomeric material" is a material that exhibits elastic properties. Elastomeric materials may include elastomeric films, scrims, nonwovens, and other sheet-like structures.

[0033] As used herein, the terms "outboard" and "inboard" refer to the position of an element disposed relatively farther from or closer to the longitudinal centerline of the diaper relative to a second element, respectively. For example, if element A is outboard of element B, element A is farther from the longitudinal centerline than element B.

[0034] As used herein, the term "pants" refers to an AHP having a pre-formed waist opening and leg openings. Pants are donned by inserting the wearer's legs into the leg openings and pulling the pants into position around the wearer's lower torso. Pants are also commonly referred to as "closed diapers," "pre-fastened diapers," "pull-on diapers," "training pants," and "diaper pants."

[0035] As used herein, the term "petrochemicals" refers to organic compounds derived from petroleum, natural gas, or coal.

[0036] As used herein, the term "petroleum" refers to crude oil and its components of paraffinic, cycloparaffinic, and aromatic hydrocarbons. Crude oil can be obtained from tar sands, asphalt fields, and oil shale.

[0037] As used herein, the term "renewable resource" refers to a natural resource that can be replenished within a period of 100 years. The resource can be replenished naturally or through agricultural technology. Renewable resources include plants, animals, fish, bacteria, fungi, and forestry products. They can be naturally occurring, hybridized, or genetically engineered organisms. Natural resources that take longer than 100 years to form, such as crude oil, coal, and peat, are not considered renewable resources.

[0038] As used herein, the term "agricultural products" refers to renewable resources obtained through the cultivation of land (eg, crops) or the raising of animals (including fish).

[0039] As used herein, the term "monomeric compound" refers to an intermediate compound that can be polymerized to produce a polymer.

[0040] As used herein, the term "polymer" refers to a macromolecule comprising repeating units, wherein the macromolecule has a molecular weight of at least 1000 g / mol. A polymer can be a homopolymer, a copolymer, a terpolymer, or the like. Polymers can be prepared via free radical, condensation, anionic, cationic, Ziegler-Natta, metallocene, or ring-opening mechanisms. Polymers can be linear, branched, and / or cross-linked.

[0041] As used herein, the term "synthetic polymer" refers to a polymer that is prepared by chemical methods from at least one monomer. Synthetic polymers are not produced directly by living organisms. For the purposes of this invention, the terms "synthetic polymer" and "polymer" are used interchangeably.

[0042] As used herein, the terms "polyethylene" and "polypropylene" refer to polymers prepared from ethylene and propylene, respectively. The polymers may be homopolymers or may contain up to about 10 mole percent of repeat units derived from a comonomer.

[0043] As used herein, the term "communication" refers to a medium or device through which information, teachings, or messages are transmitted.

[0044] As used herein, the term "relevant environmental information" refers to information that conveys the benefits or advantages of an AHP comprising a polymer derived from recycled resources. Such benefits include being more environmentally friendly, having reduced petroleum dependence, being derived from recycled resources, etc.

[0045] As used herein, the term "recovered AHP" refers to AHP that has been used for a previous purpose and then collected for recycling purposes.

[0046] As used herein, the term "recovered SAP (rSAP)" refers to SAP that was used for a previous purpose, collected for recovery purposes (as part of the collected AHP of which SAP was a part), and then prepared for a degradation process.

[0047] As used herein, the term "degraded SAP" refers to recycled SAP that has been degraded. For the purposes of the present invention, degraded SAP is PAA, and the two terms are used interchangeably. Degradation can involve decrosslinking of the SAP, breaking of crosslinked PAA chains into smaller fragments, or a combination of both.

[0048] As used herein, the term "cycloSAP" refers to a SAP obtained by the polymerization of (virgin) acrylic acid in the presence of PAA using the same method as when the SAP is prepared from virgin acrylic acid alone.

[0049] Unless otherwise indicated, all percentages herein are by weight.

[0050] II. Degraded SAP (or PAA)

[0051] Degraded SAP (or PAA) can be prepared from SAP via many methods. Non-limiting examples of SAP degradation methods are treatment in the following situations: in an extensional flow device (e.g., U.S. patent application 62 / 890,631); using hydrothermal microwaves (e.g., U.S. patent application 62 / 890,632); using ultraviolet irradiation in a flow system (e.g., U.S. patent application 16 / 548,873); using sonic / ultrasonic waves (e.g., U.S. patent application 62 / 890,880); using oxidative degradation; using hydrothermal treatment; using a combination of extensional flow device, oxidative degradation, and enzymatic degradation (e.g., U.S. patent application 63 / 039,496); using an extensional flow device and oxidative degradation (e.g., U.S. patent application 63 / 039,498); and any combination thereof.

[0052] In one embodiment of the present invention, the PAA has a weight average molecular weight of less than about 5,000,000 g / mol. In another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 2,000,000 g / mol. In yet another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 1,000,000 g / mol. In even yet another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 500,000 g / mol. In one embodiment of the present invention, the PAA has a weight average molecular weight of less than about 300,000 g / mol. In another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 200,000 g / mol. In yet another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 100,000 g / mol. In even yet another embodiment of the present invention, the PAA has a weight average molecular weight of less than about 30,000 g / mol.

[0053] In one embodiment of the present invention, the PAA has a weight average molecular weight between about 1,000,000 g / mol and about 5,000,000 g / mol. In another embodiment of the present invention, the PAA has a weight average molecular weight between about 500,000 g / mol and about 2,000,000 g / mol. In yet another embodiment of the present invention, the PAA has a weight average molecular weight between about 100,000 g / mol and about 1,000,000 g / mol. In even yet another embodiment of the present invention, the PAA has a weight average molecular weight between about 150,000 g / mol and about 500,000 g / mol. In one embodiment of the present invention, the PAA has a weight average molecular weight between about 90,000 g / mol and about 300,000 g / mol. In another embodiment of the present invention, the PAA has a weight average molecular weight between about 20,000 g / mol and about 200,000 g / mol. In yet another embodiment of the present invention, the PAA has a weight average molecular weight between about 10,000 g / mol and about 100,000 g / mol.

[0054] In one embodiment of the present invention, the PAA has a polydispersity index (PDI) of less than about 10. In another embodiment of the present invention, the PAA has a PDI of less than about 6. In yet another embodiment of the present invention, the PAA has a PDI of less than about 4. In even yet another embodiment of the present invention, the PAA has a PDI of less than about 2. PDI is the ratio of weight average molecular weight to number average molecular weight, and these molecular weights are measured by gel permeation chromatography (GPC), which is well known to those skilled in the art.

[0055] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (rSAP) produced by the steps of: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); and (ii) degrading the rSAP into a degraded material comprising poly(acrylic acid) (PAA). In another embodiment of the present invention, degradation comprises ultraviolet irradiation in a flow system. In yet another embodiment of the present invention, degradation comprises treatment in an extensional flow device. In yet another embodiment of the present invention, degradation comprises microwave-assisted hydrothermal treatment. In even yet another embodiment of the present invention, degradation comprises sonication. In one embodiment of the present invention, degradation comprises oxidative degradation.

[0056] III. CycloSAP

[0057] A. The SAP useful in the present invention can be formed by any polymerization and crosslinking technique capable of achieving the desired product properties. Typical methods for preparing these polymers are described in Reissue U.S. Patent No. 32,649, U.S. Patent Nos. 4,666,983, 4,625,001, and 5,408,019, and German Patent Application No. 4,020,780. Processing (i.e., drying, grinding, sieving, etc.) the resulting SAP to produce a usable form is well known to those skilled in the art.

[0058] Polymers can be prepared in neutralized, partially neutralized, or unneutralized forms. In one embodiment of the invention, acrylic acid is neutralized by about 50 mol % to about 95 mol %. In another embodiment of the invention, acrylic acid is neutralized by about 60 mol % to about 80 mol %. In yet another embodiment of the invention, acrylic acid is neutralized by about 67 mol %.

[0059] SAP can be prepared using a homogeneous solution polymerization method or by a heterogeneous polymerization technique (such as an inverse emulsion or suspension polymerization procedure). Polymerization reaction will generally be carried out in the presence of a relatively small amount of difunctional or multifunctional monomers such as N,N'-methylenebisacrylamide, trimethylolpropane triacrylate, ethylene glycol di(meth)acrylate, triallylamine and the methacrylate analogues of the above-mentioned acrylate. Difunctional or multifunctional monomer compounds are used for slightly cross-linking polymer chains, thereby making them water-insoluble, but water-swellable. In one embodiment of the invention, a homogeneous solution polymerization method is used to form SAP. In another embodiment of the invention, a heterogeneous polymerization method is used to form SAP. In yet another embodiment of the invention, the heterogeneous polymerization method is selected from the group consisting of an inverse emulsion polymerization method and a suspension polymerization method. In one embodiment of the invention, SAP is formed by polymerization in the presence of a difunctional or multifunctional monomer.

[0060] In one embodiment of the present invention, the SAP is made from acrylic acid and PAA. In another embodiment of the present invention, the acrylic acid is made from fossil-derived propylene. In yet another embodiment of the present invention, the acrylic acid is made from renewable resources. In even yet another embodiment of the present invention, the acrylic acid is made from lactic acid. In one embodiment of the present invention, the SAP is made from acrylic acid and PAA; wherein the acrylic acid is made from fossil-derived propylene; and wherein the PAA is a degraded SAP. In another embodiment of the present invention, the SAP is made from acrylic acid and PAA; wherein the acrylic acid is made from renewable resources; and wherein the PAA is a degraded SAP. In yet another embodiment of the present invention, the SAP is made from acrylic acid and PAA; wherein the acrylic acid is made from lactic acid; and wherein the PAA is a degraded SAP. In even yet another embodiment of the present invention, the SAP is made from acrylic acid and PAA; wherein the acrylic acid is made from renewable propylene; and wherein the PAA is a degraded SAP.

[0061] Non-limiting examples of renewable resources for making acrylic acid or propylene are sugar (from corn, sugar cane, etc.), lactic acid or its derivatives made from sugar, glycerol, 3-hydroxypropionic acid or its derivatives made from sugar, starch, starch-acrylic acid graft copolymers, itaconic acid made from sugar, ethylene made from sugar (via fermentation and dehydration), etc. Examples of the preparation of some of these materials are disclosed in U.S. Patents 3,661,875, 4,076,663, 4,093,776, 4,666,983, 4,734,478, 8,884,050, 9,611,208, and 10,723,689.

[0062] The SAP particles can be surface crosslinked after polymerization by reaction with a suitable reactive crosslinking agent. Surface crosslinking of initially formed SAP particles derived from recycled resources provides a SAP having a relatively high absorptive capacity and relatively high fluid permeability in a swollen state, as described below. Various methods for introducing surface crosslinking are disclosed in the art. Suitable methods for surface crosslinking are disclosed in U.S. Patents 4,541,871, 4,824,901, 4,789,861, 4,587,308, 4,734,478, and 5,164,459; PCT Applications WO92 / 16565, WO90 / 08789, and WO93 / 05080; German Patent Application 4,020,780, and European Patent Application 509,708. Suitable crosslinking agents include difunctional or polyfunctional crosslinking agents, such as di / polyhalogenated alkanes, di / polyepoxides, di / polyacyl chlorides, di / polytosyl alkanes, di / polyaldehydes, di / polyols, etc. In one embodiment of the present invention, the method further comprises surface crosslinking of the SAP. In another embodiment of the present invention, the method further comprises surface crosslinking of the SAP, the acrylic acid is neutralized by about 50 mol% to about 95 mol%, and the SAP is formed using homogeneous solution polymerization in the presence of a difunctional or polyfunctional monomer.

[0063] An important feature of the SAP of the present invention is the permeability or flow conductivity of a region or layer of SAP particles when swollen with body fluids. This permeability or flow conductivity is defined herein in terms of the Saline Flow Conductivity (SFC) value of the SAP. SFC measures the ability of a swollen hydrogel region or layer to transport or distribute body fluids under use pressure. It is believed that when SAP is present in a high concentration in an absorbent member and then swells under use pressure to form a hydrogel, the boundaries of the hydrogel begin to contact, and the interstitial voids in this high concentration region are generally defined by the hydrogel. When this occurs, it is believed that the permeability or flow conductivity characteristics of this region generally reflect the permeability or flow conductivity characteristics of a hydrogel region or layer formed by SAP alone. It is also believed that increasing the permeability of these swollen high concentration regions to levels approaching or even exceeding those of conventional acquisition / distribution materials such as wood pulp fluff can provide absorbent members and absorbent cores with excellent fluid handling properties, thereby reducing the occurrence of leakage, especially under high fluid loads. A higher SFC value also reflects the ability of the formed hydrogel to acquire body fluids under normal use conditions.

[0064] In one embodiment of the present invention, the SFC of the SAP is about 30×10 -7 to about 1,000×10 -7 cm 3 In another embodiment of the present invention, the SFC of the SAP is about 50×10 -7 to about 500×10 -7cm 3 In another embodiment of the present invention, the SFC of the SAP is about 100×10 -7 to about 350×10 -7 cm 3 In one embodiment of the present invention, the SFC of the SAP is at least about 30×10 -7 cm 3 In another embodiment of the present invention, the SFC of the SAP is at least about 50×10 -7 cm 3 In yet another embodiment of the present invention, the SFC of the SAP is at least about 100×10 -7 cm 3 ·s / g. The method for determining the SFC of SAP is provided below in Test Methods Section VIII.

[0065] Another important feature of the SAP of the present invention is its ability to resist swelling under load. This ability to resist load is defined in terms of the SAP's absorption against pressure (AAP) capacity. When SAP is incorporated into an absorbent member at high concentrations, the polymer needs to be able to absorb large amounts of body fluids within a reasonable period of time under use pressure. The use pressure applied to the SAP used in the AHP includes mechanical pressure (e.g., applied by the wearer's weight and movement, wrapping forces, etc.) and capillary pressure (e.g., generated by the acquisition components in the absorbent core that temporarily hold the fluid before it is absorbed by the SAP).

[0066] In one embodiment of the present invention, the AAP of the SAP is at least about 15 g / g. In another embodiment of the present invention, the AAP of the SAP is at least about 20 g / g. In yet another embodiment of the present invention, the AAP of the SAP is at least about 15 g / g to about 25 g / g. In even yet another embodiment of the present invention, the AAP of the SAP is at least about 17 g / g to about 23 g / g. In one embodiment of the present invention, the AAP of the SAP is about 20 g / g to about 23 g / g. A method for determining the AAP of SAP is provided below in Test Methods Section VIII.

[0067] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (rSAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP into a degraded material comprising poly(acrylic acid) (PAA); and (iii) polymerizing acrylic acid in the presence of the PAA to form the SAP exhibiting an Absorption Against Pressure (AAP) of at least about 15 g / g. In another embodiment of the present invention, the AAP is at least about 20 g / g. In yet another embodiment of the present invention, the SAP exhibits an AAP of at least about 30 x 10 -7 cm 3 s / g of Saline Flow Conductivity (SFC). In even yet another embodiment of the present invention, the SFC is at least about 50 x 10 -7 cm 3 In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (rSAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP into a degraded material comprising poly(acrylic acid) (PAA); and (iii) polymerizing the acrylic acid in the presence of the PAA to form a superabsorbent polymer exhibiting an absorbency against pressure (AAP) of at least about 15 g / g and a saturation of at least about 30 x 10 -7 cm 3 · The SAP has a saline flow conductivity (SFC) of 500 s / g.

[0068] B. Polyolefins - Olefins derived from renewable or recycled resources can be polymerized to produce polyolefins. Ethylene derived from renewable resources can be polymerized under appropriate conditions to produce polyethylene with desired characteristics for use in specific components of an AHP or in packaging for the AHP. The polyethylene can be high density, medium density, low density, or linear low density. Polyethylene and / or polypropylene can be produced via free radical polymerization techniques or by using Ziegler-Natta catalysis or metallocene catalysts. Polyolefins can be produced by solvent-based recovery (e.g., purification as disclosed in U.S. Patents 10,442,912, 10,450,436, and 10,465,058) or chemical recovery (i.e., pyrolysis and gasification) of spent polyolefins.

[0069] Polyolefin can be processed into the form suitable for polymer end use according to methods known in the art. Suitable forms of polyolefin include films, perforated films, microporous films, fibers, filaments, nonwovens or laminates. Suitable nonwoven forms include spunbond webs, meltblown webs and their combinations (e.g., spunbond-meltblown webs (SM), spunbond-meltblown-spunbond webs (SMS) etc.). Polyolefin can include a mixture or blend with other polymers, such as polyolefin derived from petrochemical products. Depending on the end use and form, polyolefin can include other compounds, such as inorganic compounds, fillers, pigments, dyes, antioxidants, UV stabilizers, binders, surfactants, wetting agents etc. For example, polyolefin films can be impregnated with inorganic compounds, such as calcium carbonate, titanium dioxide, clay, silicon dioxide, zeolite, kaolin, mica, carbon and their mixtures. Such compounds can be used as pore formers, which can improve the air permeability of the film when the film is strained. This method is further described in U.S. Patent No. 6,605,172. Binders can be used with polyolefin fibers, filaments or nonwoven webs. Suitable binders are available under the trade name GENFLO TM A styrene-butadiene latex binder (OMNOVA Solutions, Inc.; Akron, OH) was commercially available at 3160. The resulting binder / polyolefin fiber web can be used as an acquisition layer that can be associated with an absorbent core. Polyolefin materials, specifically polyolefin fibers, filaments, and nonwoven webs, can be treated with a surfactant or wetting agent, such as Irgasurf®. TM (Ciba Specialty Chemicals, Inc.; Tarrytown, NY).

[0070] Polyolefin nonwovens useful in AHP may have a thickness between about 1 g / m 2 and about 50g / m 2 Between or about 5g / m 2 and about 30g / m 2 The polyolefin nonwoven fabrics for use as topsheets can have a basis weight of between 100 and 200 μm, as measured according to the basis weight test provided below. The polyolefin nonwoven fabrics for use as topsheets can have an average liquid strikethrough time of less than about 4 seconds, as measured according to the liquid strikethrough test provided below. In other embodiments, the polyolefin nonwoven fabrics can have an average strikethrough time of less than about 3 seconds or less than about 2 seconds.

[0071] Polyolefin nonwovens useful as barrier leg cuffs may have a hydrostatic head greater than about 5 mbar or about 6 mbar and less than about 10 mbar or about 8 mbar, as measured according to the Hydrostatic Head Test provided below.

[0072] Polyolefin films suitable for use as a backsheet may have an MD tensile strength greater than about 0.5 N / cm or about 1 N / cm and less than about 6 N / cm or about 5 N / cm, as measured according to the Tensile Test provided below. For breathable polyolefin films suitable for use as a backsheet, the film may have a tensile strength of at least about 2000 g / m 2 / h, preferably greater than about 2,400 g / m 2 / h, even more preferably greater than about 3,000 g / m 2 / h Moisture Vapor Transmission Rate (MVTR) as measured by the Moisture Vapor Transmission Test provided below. It should be recognized that a non-breathable backsheet that can also be used in diapers will exhibit a moisture vapor transmission rate of about 0 g / m 2 / h MVTR value.

[0073] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises combining a topsheet and a backsheet to define the AHP; wherein the topsheet and the backsheet are made of a polyolefin; and wherein the polyolefin is made of waste polyolefin. In another embodiment of the present invention, the waste polyolefin is fed into a solvent-based purification process and produces a polyolefin similar to virgin polyolefin.

[0074] C. Other Polymers - It should be understood that any of the above polymers can be formed using a combination of monomers derived from renewable resources and monomers derived from non-renewable resources (e.g., petroleum). For example, the acrylic acid to be polymerized and cross-linked into the SAP can be a combination of acrylic acid derived from renewable resources and acrylic acid derived from non-renewable resources. The acrylic acid derived from renewable resources can contain at least about 5% by weight [weight of renewable resource monomers / weight of resulting polymer x 100], at least about 10% by weight, at least about 20% by weight, at least about 30% by weight, at least about 40% by weight, or at least about 50% by weight of the SAP.

[0075] IV. AHP with CycloSAP

[0076] The present invention relates to an AHP comprising a polymer derived from recycled resources. The polymer has specific performance characteristics. The polymer derived from recycled resources can be in any suitable form, such as a film, nonwoven, SAP, etc.

[0077] Figure 1A FIG2 is a plan view of an exemplary, non-limiting embodiment of an AHP in the form of a diaper 20 in a flat, uncontracted state (i.e., without elastic-induced contraction). The garment-facing surface 120 of the diaper 20 faces the viewer, while the body-facing surface 130 faces away from the viewer. The diaper 20 includes a longitudinal centerline 100 and a lateral centerline 110. Figure 1B It is taken along the lateral centerline 110 Figure 1A2. A cross-sectional view of a diaper 20 is shown. The diaper 20 may include a chassis 22. The diaper 20 and chassis 22 are shown with a front waist region 36, a back waist region 38 opposite the front waist region 36, and a crotch region 37 between the front waist region 36 and the back waist region 38. The waist regions 36 and 38 generally comprise those portions of the diaper 20 that surround the wearer's waist when worn. The waist regions 36 and 38 may include elastic elements so that they gather around the wearer's waist to provide improved fit and restraint. The crotch region 37 is that portion of the diaper 20 that is generally positioned between the wearer's legs when the diaper 20 is worn.

[0078] The outer periphery of the diaper 20 and / or chassis 22 is defined by longitudinal edges 12 and lateral edges 14. The chassis 22 may have opposing longitudinal edges 12 oriented generally parallel to the longitudinal centerline 100. However, for a better fit, the longitudinal edges 12 may be curved or angled to create, for example, an "hourglass" shaped diaper when viewed in plan. The chassis 22 may have opposing lateral edges 14 oriented generally parallel to the lateral centerline 110.

[0079] The base structure 22 may include a liquid-permeable top sheet 24, a back sheet 26, and an absorbent core 28 between the top sheet 24 and the back sheet 26. The absorbent core 28 may have a body-facing surface and a garment-facing surface. The top sheet 24 may be bonded to the core 28 and / or the back sheet 26. The back sheet 26 may be bonded to the core 28 and / or the top sheet 24. It should be appreciated that other structures, elements, or substrates may also be positioned between the core 28 and the top sheet 24 and / or the back sheet 26. In certain embodiments, the base structure 22 comprises the primary structure of the diaper 20, and other features may be added to form a composite diaper structure. The topsheet 24, backsheet 26 and absorbent core 28 may be assembled in a variety of well-known configurations, such as generally described in US Patents 3,860,003, 5,151,092, 5,221,274, 5,554,145, 5,569,234, 5,580,411, and 6,004,306.

[0080] The absorbent core 28 may comprise SAP derived from the recycled SAP of the present invention, as well as a variety of other liquid-absorbent materials commonly used in diapers and other AHPs. Examples of suitable absorbent materials include comminuted wood pulp, which is commonly referred to as airfelt; chemically stiffened, modified, or cross-linked cellulose fibers; SAP (also known as absorbent gelling material - AGM); meltblown polymers, including coformed, biosoluble vitreous microfibers; tissue, including tissue wraps and tissue laminates; absorbent foam; absorbent sponges; or any other known absorbent material or combination of materials. The exemplary absorbent structure as absorbent core 28 is described in United States Patent (USP) 4,610,678,4,673,402,4,834,735,4,888,231,5,137,537,5,147,345,5,342,338,5,260,345,5,387,207,5,397,316,5,625,222 and 6,932,800.Other exemplary absorbent structure can comprise non-removable absorbent core parts and removable absorbent core parts.This type of structure is described in U.S. Patent application 2004 / 0039361A1, 2004 / 0024379A1, 2004 / 0030314A1, 2003 / 0199844A1 and 2005 / 0228356A1. Ideally, the absorbent core 28 would be constructed entirely of materials derived from recycled SAP; however, the absorbent core 28 may contain materials derived from recycled resources.

[0081] The absorbent core 28 may comprise a fluid acquisition component, a fluid distribution component and / or a fluid storage component. Suitable absorbent cores 28 comprising an acquisition layer, a distribution layer and a storage layer are described in US Patent 6,590,136.

[0082] Another suitable absorbent core construction in which the SAP of the present invention can be used is described in U.S. Patent Application 2004 / 0167486. The absorbent cores disclosed above do not use absorbent fiber material in the core or use a very small amount of absorbent fiber material in an alternative embodiment. Generally speaking, the absorbent core can contain no more than about 20% by weight of absorbent fiber material (i.e., [weight of fiber material / total weight of absorbent core] x 100). In one embodiment of the present invention, the AHP comprises an absorbent core, wherein the absorbent core comprises no more than about 20% by weight of absorbent fiber material.

[0083] The topsheet 24 is typically a portion of the diaper 20 that can be positioned to at least partially contact or be in close proximity to the wearer. Suitable topsheets 24 can be made from a variety of materials, such as woven or nonwoven webs of natural fibers (e.g., wood fibers or cotton fibers), synthetic fibers (e.g., polyester fibers or polypropylene fibers), or a combination of natural and synthetic fibers; open-cell plastic films; porous or reticulated foams. The topsheet 24 is typically compliant, soft-feeling, and non-irritating to the wearer's skin. Generally, at least a portion of the topsheet 24 is liquid-permeable, allowing liquid to easily penetrate through the thickness of the topsheet 24. Suitably, the topsheet 24 comprises a polymer derived from a renewable or recycled resource (e.g., polyethylene). Alternatively, a suitable topsheet 24 is available from BBA Fiberweb (Brentwood, TN) under supplier code 055SLPV09U.

[0084] Any part of top flat 24 can be coated with lotion, as well known in the art.The example of suitable lotion comprises those lotions described in United States Patents 5,607,760,5,609,587,5,635,191 and 5,643,588.Top flat 24 can be elasticized or shortened in whole or in part, so that void space is provided between top flat 24 and core 28.The exemplary structure that comprises the top flat of elasticization or shortening is described in more detail in United States Patents 4,892,536,4,990,147,5,037,416 and 5,269,775.

[0085] Backsheet 26 is typically positioned so that it can be at least a portion of the garment-facing surface 120 of diaper 20. Backsheet 26 can be designed to prevent the exudates absorbed by diaper 20 and contained in the diaper from soiling articles that may contact diaper 20, such as bed sheets and underwear. In certain embodiments, backsheet 26 is substantially water-impermeable; However, backsheet 26 can be made breathable, so as to allow steam to escape while preventing liquid exudates from escaping. Polyethylene film can be made breathable by comprising inorganic particulate material and subsequently tensioning the film. Breathable backsheet can include materials such as woven webs, nonwoven webs, composite materials (such as nonwoven webs of film coating) and microporous films. Suitably, backsheet 26 comprises a polymer (such as polyethylene) derived from recycled resources or renewable resources as disclosed above. Alternative backsheets 26 derived from non-renewable resources include films manufactured by Tredegar Industries Inc. (Terre Haute, IN) and sold under the trade names X15306, X10962, and X10964; and microporous films such as those manufactured by Mitsui Toatsu Co. of Japan under the trade name ESPOIR NO and those manufactured by EXXON Chemical Co. (Bay City, TX) under the trade name EXXAIRE. Other alternative breathable backsheets 26 are described in U.S. Patents 5,865,823, 5,571,096, and 6,107,537.

[0086] Backsheet 26 may also be composed of more than one layer. For example, backsheet 26 may include an outer cover and an inner layer, or may include two outer layers and an inner layer disposed therebetween. The outer cover may have longitudinal edges, and the inner layer may have longitudinal edges. The outer cover may be made of a soft nonwoven material. The inner layer may be made of a substantially water-impermeable film. The outer cover and the inner layer may be joined together by an adhesive or any other appropriate material or method. Suitably, the nonwoven outer cover and the water-impermeable film comprise polymers (e.g., polyethylene) derived from recycled or renewable resources. Alternatively, suitable outer covers and inner layers derived from non-renewable resources may be purchased from Corovin GmbH (Peine, Germany) with supplier code A18AH0 and from RKW Gronau GmbH (Gronau, Germany) with supplier code PGBR4WPR, respectively. Although various backsheet configurations are contemplated herein, it will be apparent to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the present invention.

[0087] Diaper 20 may include a fastening system 50. When fastened, the fastening system 50 interconnects the front waist region 36 and the back waist region 38. When fastened, the diaper 20 includes a restrictive waist opening and two restrictive leg openings. The fastening system 50 may include a joining member 52 and a receiving member 54. The joining member 52 may include hooks, loops, adhesives, tackifiers, tabs or other fastening mechanisms. The receiving member 54 may include hooks, loops, slits, adhesives, tackifiers or other fastening members that may accommodate the joining member 52. The combination of suitable joining member 52 and receiving member 54 is well known in the art, and includes but is not limited to hooks / loops, hooks / hook, adhesives / polymer films, adhesives / tackifiers, adhesives / tackifiers, tabs / slits and buttons / buttonholes. Suitably, the fastening system 50 may include a polymer derived from recovery or renewable resources (for example, polyethylene film or polyethylene nonwoven).

[0088] The diaper 20 may include front ears (not shown) and / or back ears 42. The front ears and / or back ears 42 may be integral elements of the diaper 20 (i.e., they are not separately manipulated elements secured to the diaper 20, but are formed from and are extensions of one or more of the various layers of the diaper). In certain embodiments, the front ears and / or back ears 42 may be discrete elements joined to the chassis 22, such as Figure 1AAs shown. Discrete front ear and / or back ear 42 can be joined to infrastructure 22 by any bonding method known in the art such as adhesive bonding, pressure bonding, thermal bonding etc. In other embodiments, front ear and / or back ear 42 may comprise discrete elements joined to infrastructure 22, wherein infrastructure 22 has a layer, element or substrate extending above front ear and / or back ear 42. Front ear and back ear 42 may be extensible, inextensible, elastic or inelastic. Front ear and back ear 42 may be formed by the following materials: nonwoven web, woven web, knitted fabric, polymer film and elastomeric film, apertured film, sponge, foam, scrim and combinations and laminates thereof. In certain embodiments, front ear and back ear 42 may be formed by a stretch laminate comprising a first nonwoven 42a, an elastomeric material 42b and an optional second nonwoven 42c or other similar laminates. The first nonwoven 42a and the second nonwoven 42c can comprise polymers derived from recycled or renewable resources (e.g., polyethylene). Suitable elastomeric materials 42b can comprise natural elastomers, such as natural rubber, or can comprise synthetic elastomers, such as elastomeric films available from Tredegar Corp (Richmond, VA) under the supplier code X25007. An alternative stretch laminate can be formed from Tredegar X25007 elastomer (available from BBA Fiberweb (Brentwood, TN) under the supplier code FPN332) disposed between the two nonwoven layers.

[0089] The diaper 20 may also include leg cuffs 32a, 32b that may improve the containment of liquids and other body exudates. The leg cuffs 32a, 32b may also be referred to as gasketing cuffs, outer leg cuffs, leg bands, side flaps, elastic cuffs, barrier cuffs, secondary cuffs, inner leg cuffs, or "stand-up" elastic flaps. U.S. Patent 3,860,003 describes a disposable diaper that provides retractable leg openings having side flaps and one or more elastic members to provide elastic leg cuffs (i.e., gasketing cuffs). U.S. Patents 4,808,178 and 4,909,803 describe disposable diapers with "stand-up" elastic flaps (i.e., barrier cuffs) that improve containment of the leg regions. U.S. Patents 4,695,278 and 4,795,454 describe disposable diapers with double cuffs (including gasketing cuffs and barrier cuffs).

[0090] Figure 1A to Figure 1BA diaper 20 is shown having two cuffs (a gasketing cuff 32a and a barrier cuff 32b). The barrier cuff 32b may include one or more barrier elastic members 33b. The barrier elastic members 33b may be joined to a barrier cuff substrate 34. The barrier cuff substrate 34 may comprise a polymer derived from recycled or renewable resources. In certain embodiments, the barrier cuff substrate 34 may be a polymer film or a nonwoven. The barrier cuff 32b may be disposed on the body-facing surface of the chassis 22. The barrier cuff substrate 34 may extend laterally from the longitudinal edge 12 of the chassis 22 to a point inboard of the longitudinal edge 122. The barrier cuff 32b typically extends longitudinally at least through the crotch region 37. The barrier elastic members 33b allow a portion of the barrier cuff 32b to be spaced apart from the body-facing surface of the diaper 20.

[0091] The gasketing cuff 32a may include one or more gasketing elastic members 33a. The gasketing elastic members 33a may be joined to one or more of the existing elements or substrates of the diaper 20 (e.g., the topsheet 24, the backsheet 26, the barrier cuff substrate 34, etc.). In some embodiments, it may be desirable to treat all or a portion of the leg cuffs 32 with a hydrophilic surface coating, such as described in U.S. Patent Application 2005 / 0177123A1. Suitable gasketing and barrier elastic members 33a, 33b include natural rubber, synthetic rubber, and other elastomers.

[0092] In other suitable embodiments, the diaper 20 may be pre-formed by the manufacturer to form a pant. The pant may be pre-formed by any suitable technique, including but not limited to joining parts of the product together using refastenable and / or non-refastenable bonds (e.g., seams, welding, adhesives, cohesive bonds, fasteners, etc.). For example, Figure 1A The diaper 20 can be manufactured with an engaged fastening system 50 (ie, the engaging member 52 is engaged to the receiving member 54). As an additional example, Figure 1A The diaper 20 can be manufactured with the front ears 40 joined to the back ears 42 by bonding, such as adhesive bonding, mechanical bonding, or some other bonding technique known in the art. Suitable pants are disclosed in U.S. Patents 5,246,433, 5,569,234, 6,120,487, 6,120,489, 4,940,464, 5,092,861, 5,897,545, and 5,957,908.

[0093] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by the following steps: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA); and (iii) polymerizing acrylic acid in the presence of the PAA to form the SAP exhibiting an absorption against pressure (AAP) of at least about 15 g / g; and b) combining the SAP with AHP components including a topsheet and a backsheet to define the AHP. In another embodiment of the present invention, a method for providing AHP to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA) via treatment in an extensional flow device; and (iii) polymerizing the acrylic acid in the presence of the PAA to form a superabsorbent polymer exhibiting an absorbency against pressure (AAP) of at least about 15 g / g and an absorbency against pressure of at least about 30 x 10 -7 cm 3 s / g; and b) combining the SAP with an AHP component comprising a topsheet and a backsheet to define the AHP.

[0094] V. Provide AHP to consumers

[0095] One or more AHPs (e.g., diapers) 220 may be provided as a package 200, such as Figures 2A to 2B Generally speaking, the package 200 allows a quantity of AHP 220 to be provided to and purchased by a consumer while saving space and simplifying transportation and storage. The package 200 includes at least one AHP 220 secured by an outer wrapper 250. The outer wrapper 250 may partially or completely cover the AHP, which may be compressed or uncompressed. Figure 2AShown is an outer wrapper 250 that covers and encapsulates multiple AHP220 completely. Outer wrapper 250 can comprise various materials, include but not limited to thermoplastic film, nonwoven, woven fabric, foil, fabric, paper, cardboard, elastic component, rope, belt and their combination.Other suitable packaging structures and outer wrapper are described in United States Patents 4,846,587, 4,934,535, 4,966,286, 5,036,978, 5,050,742 and 5,054,619.In certain embodiments, outer wrapper 250 comprises the polymer (for example, polyolefin) derived from recovery or renewable resources.Although the shape of packing 200 is not restricted, it is expected that packing 200 has parallelepiped or is substantially similar to the shape of parallelepiped (for example, having at least substantially flat base and four substantially flat sides).This shape is ideal for packing, stacking and transporting. The size of the package 200 is not limited; however, in certain embodiments, the size of the package 200 should be no larger than that required to accommodate the AHP 220 .

[0096] The package 200 can have a handle 240. In some embodiments, the handle 240 can be a discrete element, such as a strap, that can be attached to the overwrap 250. Figures 2A to 2B In the embodiment shown, the handle 240 is integral with the overwrap 250. For this embodiment, the handle 240 can include an extension 252 from the overwrap 250. The extension 252 can have a hole 254 therethrough. The hole 254 is ideally sized to allow entry of one or more fingers of an adult's hand.

[0097] An opening device 260 may be provided in the outer wrapper 250. For example, the opening device 260 may include a line of weakness 262 (e.g., a perforation) in the outer wrapper 250 made of paper, cardboard, or film. The opening device 260 allows for partial or complete removal of a flap 256 that is part of the outer wrapper 250. Partial or complete removal of the flap 256 may allow for improved access to the AHP 220. The opening device 260 and the flap 256 may be provided in a manner similar to the embodiment of the invention. Figure 2A is shown in a closed configuration and in Figure 2B An exemplary opening device 260 is disclosed in US Patent Application 5,036,978.

[0098] The package 200 may include a plurality of overwraps 250. For example, a plurality of AHPs may be secured with a first overwrap, such as a thermoplastic film, and then the plurality of film-wrapped AHPs may be secured in a second overwrap, such as a cardboard box or another thermoplastic film.

[0099] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA); and (iii) polymerizing acrylic acid in the presence of the PAA to form the SAP exhibiting an absorption against pressure (AAP) of at least about 15 g / g; b) combining the SAP with AHP components including a topsheet and a backsheet to define the AHP; and c) disposing the AHP in a package. In another embodiment of the present invention, a method for providing AHP to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA) via treatment in an extensional flow device; and (iii) polymerizing the acrylic acid in the presence of the PAA to form a superabsorbent polymer exhibiting an absorbency against pressure (AAP) of at least about 15 g / g and an absorbency against pressure of at least about 30 x 10 -7 cm 3 s / g; b) combining the SAP with an AHP component comprising a topsheet and a backsheet to define the AHP; and c) arranging the AHP in a package.

[0100] VI. Communicate relevant environmental information to consumers

[0101] The present invention may also include relevant environmental information, or may also include the step of communicating relevant environmental information to consumers. The relevant environmental information may convey the benefits or advantages of the AHP comprising polymers derived from recycled or renewable resources. The relevant environmental information may identify the AHP as: environmentally friendly or earth-friendly; having reduced petroleum (or oil) dependence or content; having reduced foreign petroleum (or oil) dependence or content; having reduced petrochemicals or having components that do not contain petrochemicals; and / or being made from recycled or renewable resources or having components made from recycled or renewable resources. This communication is important for consumers who may have an aversion to the use of petrochemicals (for example, consumers who are concerned about the depletion of natural resources or consumers who find petrochemical-based products unnatural or environmentally unfriendly) and for consumers who are environmentally conscious. Without such communication, the benefits of the present invention may be lost on some consumers.

[0102] Communication can be accomplished in a variety of communication formats. Suitable communication formats include store displays, posters, notices, computer programs, brochures, packaged literature, shelf information, videos, advertisements, internet websites, pictograms, icons, or any other suitable form of communication. Information can be made available in stores, on television, in computer-accessible formats, in advertisements, or in any other suitable location. Ideally, a variety of communication formats can be used to disseminate relevant environmental information.

[0103] The communication may be written, oral, or delivered via one or more pictures, graphics, or icons. For example, television or internet-based advertising may include a narration, voiceover, or other auditory transmission of the relevant environmental message. Similarly, the relevant environmental message may be delivered in written form using any suitable communication format listed above. In certain embodiments, it is desirable to quantify the reduction in petrochemical usage of the AHPs of the present invention compared to currently commercially available AHPs.

[0104] In other embodiments, the communication form may be one or more icons. Figures 3A to 3F Several suitable embodiments of communication are shown in the form of icons 310. One or more icons 310 may be used to communicate environmental information related to reduced petrochemical use. Suitable icons 310 for communicating environmental information related to reduced petrochemical use are shown in FIG. Figures 3A to 3B Icons conveying environmental friendliness or related environmental information such as recycling or use of renewable resources are shown in Figures 3C to 3F In certain embodiments, the icon 310 may be located on a package 200 (e.g., Figures 2A to 2B as shown), on the AHP, on an adjacent package or plug-in to the AHP, or in combination with any other form of communication listed above.

[0105] Relevant environmental information may also include information on petrochemical equivalence. As described in the background, many recycled or renewable, naturally occurring, or non-petroleum-derived polymers have been disclosed. However, when used in AHPs, these polymers often lack the performance characteristics expected by consumers. Therefore, information on petroleum equivalence may be necessary to inform consumers that polymers derived from recycled or renewable resources, as described above, exhibit equivalent or better performance characteristics than polymers derived from petroleum. Suitable petrochemical equivalence information may include a comparison with an AHP that does not have polymers derived from recycled or renewable resources. For example, a suitable combined message may be "Diaper brand A with environmentally friendly absorbent materials is as absorbent as diaper brand B." This information conveys relevant environmental information and petrochemical equivalence information.

[0106] In one embodiment of the present invention, a method for providing an absorbent hygiene product (AHP) to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA); and (iii) polymerizing acrylic acid in the presence of the PAA to form the SAP exhibiting an absorbency against pressure (AAP) of at least about 15 g / g; b) combining the SAP with AHP components including a topsheet and a backsheet to define the AHP; c) disposing the AHP in a package; and d) communicating environmental information to the consumer to convey that the AHP comprises materials derived from recycled resources. In another embodiment of the present invention, a method for providing AHP to a consumer comprises: a) providing a superabsorbent polymer (SAP) prepared by: (i) separating recycled SAP (rSAP) from recycled AHP (rAHP); (ii) degrading the rSAP to a material comprising poly(acrylic acid) (PAA) via treatment in an extensional flow device; and (iii) polymerizing the acrylic acid in the presence of the PAA to form a superabsorbent polymer exhibiting an absorbency against pressure (AAP) of at least about 15 g / g and an absorbency against pressure of at least about 30 x 10 -7 cm 3 s / g; b) combining the SAP with an AHP component comprising a topsheet and a backsheet to define the AHP; c) disposing the AHP in a package; and d) conveying an environmental message to the consumer to convey that the AHP comprises materials derived from recycled resources. In yet another embodiment of the present invention, the environmental message is disposed on the packaging. In yet another embodiment of the present invention, the environmental message is conveyed in an advertisement for the AHP.

[0107] VII. Method for preparing AHP with CycloSAP

[0108] The present invention also relates to a method for preparing an AHP comprising SAP derived from recycled resources. The method comprises the steps of providing recycled SAP (rSAP); degrading the rSAP to produce poly(acrylic acid) (PAA); polymerizing and crosslinking the acrylic acid in the presence of the PAA to form an AHP having a molecular weight of at least about 30×10 -7 cm 3s / g and an absorbency against pressure of at least about 15 g / g; and incorporating the SAP into an AHP. The present invention also relates to providing one or more AHPs to consumers and communicating to them the reduced use of petrochemicals. Polymers derived from recycled resources may undergo additional processing steps before incorporation into the AHP. Such processing steps include drying, screening, surface crosslinking, and the like.

[0109] VIII. Test Methods

[0110] Saline Flow Conductivity - The method for determining the permeability of the swollen hydrogel layer 718 is "Saline Flow Conductivity," also known as "gel layer permeability," and is described in several references, including European Patent Application 640,330, U.S. Patent Applications 11 / 349,696, 11 / 347,406, and 06 / 682,483, and U.S. Patent 4,469,710. The apparatus used for this method is described below.

[0111] Permeability Measurement System- Figure 4 A permeability measurement system 400 is shown equipped with a constant hydrostatic head reservoir 414, an open-ended tube 410 for air entry, a plug 412 for refilling, a laboratory stand 416, a transfer tube 418, a stopcock 420, a ring stand support 422, a receiving container 424, a balance 426, and a piston / cylinder assembly 428.

[0112] Figure 5 The piston / cylinder assembly 428 is shown including a metal weight 512, a piston shaft 514, a piston head 518, a cover 516, and a cylinder 520. The cylinder 520 is made of a transparent polycarbonate (e.g., ) and has an inner diameter (p) of 6.00 cm (area = 28.27 cm 2 ), wherein the inner cylindrical wall 550 is smooth. The bottom 548 of the cylinder 520 faces a U.S. standard 400 mesh stainless steel screen cloth (not shown), which is biaxially stretched to tautness before being attached to the bottom 548 of the cylinder 520. The piston shaft 514 is made of a clear polycarbonate (e.g., ) and has an overall length q of approximately 127 mm. The middle portion 526 of the piston shaft 514 has a diameter (r) of 21.15 mm. The upper portion 528 of the piston shaft 514 has a diameter (s) of 15.8 mm, thereby forming the shoulder 524. The lower portion 546 of the piston shaft 514 has a diameter (t) of approximately 5 / 8 inches and is threaded to securely screw into the central hole 618 of the piston head 518 (see Figure 6 ). The piston head 518 is perforated and made of a transparent polycarbonate (e.g., ) and is also screened with stretched U.S. Standard 400 mesh stainless steel screen cloth (not shown). The weight 512 is stainless steel with a center hole 530, slides onto the upper portion 528 of the piston shaft 514 and rests on the shoulder 524. The combined weight of the piston head 518, piston shaft 514 and weight 512 is 596g (± 6g), which corresponds to 0.30psi over the area of ​​the cylinder 520. The combined weight can be adjusted by drilling a blind hole down along the center axis 532 of the piston shaft 514 to remove material and / or provide a cavity to add weights. The cylinder cover 516 has a first cover opening 534 at its center for vertically aligning the piston shaft 514 and a second cover opening 536 near the edge 538 for introducing fluid from the constant static head reservoir 414 into the cylinder 520.

[0113] A first linear indicator mark (not shown) is radially drawn along the upper surface 552 of the weight 512, the first linear indicator mark being transverse to the central axis 532 of the piston shaft 514. A corresponding second linear indicator mark (not shown) is radially drawn along the top surface 560 of the piston shaft 514, the second linear indicator mark being transverse to the central axis 532 of the piston shaft 514. A corresponding third linear indicator mark (not shown) is drawn along the middle portion 526 of the piston shaft 514, the third linear indicator mark being parallel to the central axis 532 of the piston shaft 514. A corresponding fourth linear indicator mark (not shown) is radially drawn along the upper surface 540 of the cylinder cover 516, the fourth linear indicator mark being transverse to the central axis 532 of the piston shaft 514. Additionally, a corresponding fifth linear indicator mark (not shown) is drawn along the lip 554 of the cylinder cover 516, the fifth linear indicator mark being parallel to the central axis 532 of the piston shaft 514. A corresponding sixth linear indicator mark (not shown) is scored along the outer cylinder wall 542 and is parallel to the central axis 532 of the piston shaft 514. Aligning the first, second, third, fourth, fifth, and sixth linear indicator marks allows the weight 512, piston shaft 514, cylinder cover 516, and cylinder 520 to be repositioned in the same orientation relative to one another for each measurement.

[0114] The specifications of the cylinder 520 are as follows: outer diameter (u) of the cylinder 520: 70.35 mm; inner diameter (p) of the cylinder 520: 60.0 mm; and height (v) of the cylinder 520: 60.5 mm. The specifications of the cylinder cover 516 are as follows: outer diameter (w) of the cylinder cover 516: 76.05 mm; inner diameter (x) of the cylinder cover 516: 70.5 mm; thickness (y) of the cylinder cover 516 including the lip 554: 12.7 mm; thickness (z) of the cylinder cover 516 excluding the lip: 6.35 mm; diameter (a) of the first cover opening 534: 22.25 mm; diameter (b) of the second cover opening 536: 12.7 mm; and distance between the centers of the first and second cover openings 534, 536: 23.5 mm. The weight 512 has the following specifications: outer diameter (c): 50.0 mm; center hole 530 diameter (d): 16.0 mm; and height (e): 39.0 mm. The piston head 518 has the following specifications: diameter (f): 59.7 mm; height (g): 16.5 mm; outer holes 614 (14 in total) have a diameter (h) of 9.65 mm, and are evenly spaced, with their centers 47.8 mm from the center of the center hole 618; inner holes 616 (7 in total) have a diameter (i) of 9.65 mm, and are evenly spaced, with their centers 26.7 mm from the center of the center hole 618; and the center hole 618 has a diameter (j) of 5 / 8 inches and is threaded to receive the lower portion 546 of the piston shaft 514.

[0115] Before use, the stainless steel screens (not shown) of the piston head 518 and cylinder 520 should be checked for blockage, holes, or overstretching and replaced if necessary. An SFC device with a damaged screen may output erroneous SFC results and should not be used until the screen is replaced.

[0116] A 5.00 cm mark 556 is made on the cylinder 520 at a height (k) of 5.00 cm (±0.05 cm) above the screen (not shown) attached to the bottom 548 of the cylinder 520. This marks the fluid level to be maintained during analysis. Maintaining a correct and constant fluid level (hydrostatic pressure) is critical to measurement accuracy.

[0117] The saline solution 432 is delivered to the cylinder 520 using the constant static head reservoir 414, and the level of the saline solution 432 is maintained at a height (k) of 5.00 cm above a screen (not shown) attached to the bottom 548 of the cylinder 520. The bottom 434 of the inlet tube 410 is positioned to maintain the level of the saline solution 432 in the cylinder 520 at the desired height (k) of 5.00 cm during measurement, i.e., the bottom 434 of the inlet tube 410 and the 5.00 cm mark 556 on the cylinder 520 are approximately in the same plane 438 when the cylinder is positioned on a support screen (not shown) on a ring stand 440 above the receiving container 424. Proper height alignment of the inlet tube 410 with the 5.00 cm mark 556 on the cylinder 520 is critical to the analysis. A suitable reservoir 414 consists of a jar 430 comprising a horizontally oriented L-shaped transfer tube 418 for fluid transfer, a vertically oriented open-ended tube 410 for admitting air at a fixed height within the constant static head reservoir 414, and a stopcock 412 for refilling the constant static head reservoir 414. The tube 410 has an inner diameter of xx mm. The transfer tube 418, positioned near the bottom 442 of the constant static head reservoir 414, houses a stopcock 420 for starting / stopping the delivery of saline solution 432. The outlet 444 of the transfer tube 418 is sized to be inserted through a second cap opening 536 in the cylinder cap 516, with its end positioned below the surface of the saline solution 432 in the cylinder 520 (after the saline solution 432 reaches a height of 5.00 cm in the cylinder 520). The air inlet tube 410 is held in place by an O-ring bushing (not shown). The constant static head reservoir 414 can be positioned on the laboratory stand 416 so that its height can be adjusted relative to the height of the cylinder 520. The components of the constant static head reservoir 414 are sized to quickly fill the cylinder 520 to the desired height (i.e., static head) and maintain that height for the duration of the measurement. The constant static head reservoir 414 must be capable of delivering saline solution 432 at a flow rate of at least 3 g / s for at least 10 minutes.

[0118] The piston / cylinder assembly 428 is positioned on a 16 mesh rigid stainless steel support screen (not shown) (or equivalent), which is supported on a ring stand 440 or a suitable alternative rigid stand. The support screen (not shown) is sufficiently permeable so as not to impede the flow of the saline solution 432 and rigid enough to support the stainless steel mesh (not shown) to prevent stretching. The support screen (not shown) should be flat and horizontal to avoid tilting the piston / cylinder assembly 428 during testing. The saline solution 432 that passes through the support screen (not shown) is collected in a receiving container 424 located below the support screen (not shown) (but not supporting the support screen). The receiving container 424 is positioned on a balance 426 accurate to at least 0.01 g. The digital output of the balance 426 is connected to a computerized data acquisition system (not shown).

[0119] Reagent preparation (not shown) - Jayco synthetic urine (JSU) 712 (see Figure 7 ) was used as the swelling phase (see SFC procedure below), and 0.118 M sodium chloride (NaCl) solution was used as the mobile phase (see SFC procedure below). A 1 liter volume of a reference standard was prepared below. If preparing a volume different from 1 liter, all amounts were weighed accordingly.

[0120] JSU: Fill a 1 L volumetric flask to 80% of its volume with distilled water and place a magnetic stir bar inside the flask. Using an analytical balance, weigh the following dry ingredients to the nearest ±0.01 g using weighing paper or a beaker. Add them quantitatively to the flask in the same order listed below. Stir the solution on a suitable stir plate until all solids have dissolved. Remove the stir bar and dilute the solution to 1 L with distilled water. Replace the stir bar and stir the solution on the stir plate for a few more minutes.

[0121] The salt amounts used to prepare 1 liter of Jayco synthetic urine are: 2.00 g of potassium chloride (KCl); 2.00 g of sodium sulfate (Na2SO4); 0.85 g of monoammonium phosphate (NH4H2PO4); 0.15 g of diammonium phosphate ((NH4)2HPO4); 0.19 g of calcium chloride (CaCl2) [or 0.25 g of hydrated calcium chloride (CaCl2·2H2O)]; and 0.23 g of magnesium chloride (MgCl2) [or 0.50 g of hydrated magnesium chloride (MgCl2·6H2O)].

[0122] To make preparation faster, dissolve each salt completely before adding the next substance. Jayco Synthetic Urine can be stored in a clean glass container for 2 weeks. If the solution becomes cloudy, it should not be used. The shelf life in a clean plastic container is 10 days.

[0123] 0.118 M Sodium Chloride (NaCl) Solution: Use 0.118 M NaCl as Salt Solution 432. Using weighing paper or a beaker, weigh 6.90 g (± 0.01 g) of sodium chloride and quantitatively transfer it to a 1 L volumetric flask. Fill the flask to volume with distilled water. Add a stir bar and stir the solution on a stir plate until all solids have dissolved.

[0124] Test Preparation - Using a solid reference cylindrical weight (not shown) (40 mm diameter; 140 mm height), set the reading of a caliper (not shown) (e.g., a Mitotoyo electronic digital height gauge) to zero. This operation is conveniently performed on a smooth and level workbench 446. Position the SAP-free piston / cylinder assembly 428 under the caliper (not shown) and record the reading L1 to the nearest 0.01 mm.

[0125] The constant static head reservoir 414 is filled with saline solution 432. The bottom 434 of the inlet tube 410 is positioned so that the top (not shown) of the liquid meniscus (not shown) in the cylinder 520 is maintained at the 5.00 cm mark 556 during the measurement. Proper height alignment of the inlet tube 410 at the 5.00 cm mark 556 on the cylinder 520 is critical to the analysis.

[0126] The receiving container 424 is placed on a balance 426, and the digital output of the balance 426 is connected to a computerized data acquisition system (not shown). A ring stand 440 with a 16-mesh rigid stainless steel support screen (not shown) is positioned above the receiving container 424. The 16-mesh screen (not shown) should be rigid enough to support the piston / cylinder assembly 428 during the measurement. The support screen (not shown) must be flat and level.

[0127] SFC Procedure - Using an analytical balance, weigh 0.9 g (± 0.05 g) of SAP onto appropriate weighing paper. Using an analytical balance, weigh 0.9 g (± 0.05 g) of SAP onto appropriate weighing paper. Measure the moisture content of the SAP according to EDANA Moisture Content Test Method 430.1-99 ("Superabsorbent materials - Polyacrylate superabsorbent powders - Moisture Content - Weight Loss Upon Heating" (February '99)). If the moisture content of the polymer is greater than 5%, the polymer weight should be corrected for moisture (i.e., the added polymer should be 0.9 g on a dry weight basis).

[0128] The empty cylinder 520 is placed on a horizontal workbench 446 and the SAP is quantitatively transferred into the cylinder 520. By gently shaking, rotating and / or tapping the cylinder 520, the SAP particles are evenly dispersed on the screen (not shown) attached to the bottom 548 of the cylinder 520. The uniform distribution of particles on the screen (not shown) attached to the bottom 548 of the cylinder 520 is important to obtain the highest precision results. After the SAP has been evenly distributed on the screen (not shown) attached to the bottom 548 of the cylinder 520, the particles must not adhere to the inner cylinder wall 550. The piston shaft 514 is inserted through the first cover opening 534, wherein the lip 554 of the cover 516 faces the piston head 518. The piston head 518 is carefully inserted into the cylinder 520 to a depth of several centimeters. The cover 516 is then placed on the upper edge 544 of the cylinder 520, while paying attention to keeping the piston head 518 away from the SAP. The cover 516 and piston shaft 526 are then carefully rotated so that the third, fourth, fifth, and sixth linear indicators are aligned. The piston head 518 is then gently lowered (via the piston shaft 514) to rest on the dry SAP. The weight 512 is positioned on the upper portion 528 of the piston shaft 514 so that it rests on the shoulder 524, aligning the first linear indicator with the second linear indicator. Proper seating of the cover 516 prevents sticking and ensures even distribution of weight on the hydrogel layer 718.

[0129] Swelling Phase: An 8 cm diameter fritted disk (7 mm thick; e.g., Chemglass Inc. #CG 201-51, coarse porosity) 710 is saturated by adding excess JSU 712 to the fritted disk 710 until the fritted disk 710 is saturated. The saturated fritted disk 710 is placed in a wide, flat-bottomed Petri dish 714, and JSU 712 is added until it reaches the top surface 716 of the fritted disk 710. The height of the JSU must not exceed the height of the fritted disk 710.

[0130] The screen (not shown) attached to the bottom 548 of the cylinder 520 is prone to stretching. To prevent stretching, while grasping the cylinder 520 of the piston / cylinder assembly 428, use your index finger to apply lateral pressure on the piston shaft 514 just above the cover 516. This "locks" the piston shaft 514 in place against the cover 516, allowing the piston / cylinder assembly 428 to be lifted without exerting undue force on the screen (not shown).

[0131] The entire piston / cylinder assembly 428 is lifted in this manner and placed on the sintered disk 710 in the culture dish 714. The JSU 712 from the culture dish 714 passes through the sintered disk 710 and is absorbed by the SAP (not shown) to form a hydrogel layer 718. The JSU 712 available in the culture dish 714 should be sufficient for all swelling phases. If necessary, more JSU 712 can be added to the culture dish 714 during hydration to maintain the level of JSU 712 at the top surface 716 of the sintered disk 710. After a period of 60 minutes, the piston / cylinder assembly 428 is removed from the sintered disk 710, taking care to lock the piston shaft 514 against the cap 516 as described above and to ensure that the hydrogel layer 718 does not lose JSU 712 or absorb air during this process. The piston / cylinder assembly 428 is placed under a calliper (not shown) and the reading L2 is recorded to the nearest 0.01 mm. If the reading changes over time, only the initial value is recorded. The thickness L0 of the hydrogel layer 718 is determined by L2-L1, accurate to 0.1 mm.

[0132] The entire piston / cylinder assembly 428 is lifted in the manner described above and placed on a support screen (not shown) attached to the ring stand 440. During this process, care should be taken to ensure that the hydrogel layer 718 does not lose JSU 712 or absorb air. The JSU 712 available in the culture dish 714 should be sufficient for all swelling phases. If necessary, more JSU 712 can be added to the culture dish 714 during hydration to maintain the JSU 712 level at the 5.00 cm mark 556. After a period of 60 minutes, the piston / cylinder assembly 428 is removed, taking care to lock the piston shaft 514 against the cap 516 as described above. The piston / cylinder assembly 428 is placed under a caliper (not shown), and the caliper (not shown) is measured as L2 to the nearest 0.01 mm. The thickness L0 of the hydrogel layer 718 is determined by L2-L1 to the nearest 0.1 mm. If the reading changes over time, only the initial value is recorded.

[0133] Transfer the piston / cylinder assembly 428 to a support screen (not shown) attached to the ring support frame 440, taking care to lock the piston shaft 514 in place against the cover 516. Position the constant static head reservoir 414 so that the transfer tube 418 is placed through the second cover opening 536. Begin the measurement in the following sequence:

[0134] a) Open the stopcock 420 of the constant hydrostatic head reservoir 410 to allow the saline solution 432 to reach the 5.00 cm mark 556 on the cylinder 520. This saline solution 432 level should be achieved within 10 seconds of opening the stopcock 420.

[0135] b) Once 5.00 cm of saline solution 432 is obtained, the data collection procedure is initiated.

[0136] The amount of saline solution 432 that passes through the hydrogel layer 718 is recorded at 20 second intervals for 10 minutes using a computer (not shown) attached to the balance 426. At the end of the 10 minutes, the stopcock 420 on the constant hydrostatic head reservoir 410 is closed. The piston / cylinder assembly 428 is immediately removed, placed under a caliper (not shown), and the reading L3 is recorded to the nearest 0.01 mm. The final thickness L of the hydrogel layer 718 is f The percentage change in thickness of the hydrogel layer 718 is determined by L3-L1, accurate to 0.1 mm, as described above. f / L0)×100. Generally speaking, the thickness of the hydrogel layer 718 varies within about ±10%. The data from 60 seconds to the end of the experiment are used in the SFC calculation. The data collected before 60 seconds are not included in the calculation. s (in g / s) is the slope of a linear least squares fit to a plot of the weight of saline solution 432 collected (in g) as a function of time (in seconds) from 60 s to 600 s.

[0137] In a separate measurement, the flow rate (F a ), except that there is no hydrogel layer 718. If F a Much greater than the flow rate F through the permeability measurement system 400 when the hydrogel layer 718 is present. s , then no correction for the flow resistance of the permeability measurement system 400 (including the piston / cylinder assembly 428) is required. In this limit, F g =F s , where F g is the contribution of the hydrogel layer 718 to the flow rate of the permeability measurement system 400. However, if this requirement is not met, the following correction is used: s and F a Calculate the value of F g Value:

[0138] F g =(F a ×F s ) / (F a -F s )

[0139] The saline flow conductivity (K) of the hydrogel layer 718 is calculated using the following formula:

[0140] K=[F g (t=0)×L0] / [ρ×A×ΔP],

[0141] Among them F gis the flow rate (in g / s) determined from the regression analysis of the flow rate results and any correction due to the flow resistance of the permeability measurement system 400, L0 is the initial thickness of the hydrogel layer 718 (in cm), and p is the density of the saline solution 432 (in gm / cm 3 A (derived from the above formula) is the area of ​​the hydrogel layer 718 (in cm 2 ΔP is the static pressure of the fluid (in dynes / cm 2 ), and the saline flow conductivity K is in cm 3 The unit is s / gm. The average value of three measurements should be recorded.

[0142] For a hydrogel layer 718 in which the flow rate is substantially constant, the permeability coefficient (κ) can be calculated from the saline flow conductivity using the following formula:

[0143] κ=Kη

[0144] Where η is the viscosity of the saline solution 432 in poise, and the permeability coefficient κ is in cm 2 As a unit.

[0145] In general, the flow rate need not be constant. The time-dependent flow rate F through the system is determined by dividing the incremental weight (in grams) of saline solution 432 passing through the permeability measurement system 400 by the incremental time (in seconds). S (t) in g / s. Only the data collected between 60 s and 10 min are used in the flow rate calculation. Use the flow rate results between 60 s and 10 min to calculate F s (t=0), i.e., the initial flow rate through the hydrogel layer 718. S The results of the least squares fit of (t) versus time are extrapolated to t = 0 to calculate F s (t=0).

[0146] Absorbency Against Pressure - This test measures the amount of 0.9% saline solution absorbed by a SAP that is laterally restrained in a piston / cylinder assembly under confining pressure for a period of one hour. European Disposables and Nonwovens Association (EDANA) test method 442.2-02, entitled "Absorbency Against Pressure," is used.

[0147] Basis Weight - This test measures the mass per unit area of ​​a substrate. European Disposables and Nonwovens Association (EDANA) test method 40.3-90 entitled "Mass per Unit Area" was used.

[0148] Liquid Strike Through - This test measures the time it takes for a known volume of liquid applied to the surface of a substrate to pass through the substrate to the absorbent pad underneath. European Disposables and Nonwovens Association (EDANA) test method 150.4-99, entitled "Liquid Strike Through Time," was used.

[0149] Tensile Test - This test measures the peak load exhibited by the substrate. The preferred equipment for performing the test is a tensile tester such as an MTS Synergie 100 or MTS Alliance, equipped with a computer interface and Testworks 4 software, available from MTS Systems Corporation (14000 Technology Drive, Eden Prairie, MN, USA). This instrument measures a constant rate of extension, in which the pulling grip moves at a uniform rate and the force measuring mechanism moves a negligible distance (less than 0.13 mm) as the force increases. The load cell is selected so that the measured load (e.g., force) of the test sample will be between 10% and 90% of the capacity of the load cell (typically a 25N or 50N load cell).

[0150] Use anvil hydraulic punch die to cut 1 × 1 inch (2.5 × 2.5cm) samples from substrate to cut the film into individual samples with a die. Produce a minimum of three samples that are substantially free of visible defects such as bubbles, holes, inclusions, and cuts. Each sample must have a smooth and substantially defect-free edge. The test is carried out in a conditioning chamber at a temperature of 23°C (± 1°C) and a relative humidity of 50% (± 2%) for at least 2 hours. Prior to testing, the sample is allowed to equilibrate in the conditioning chamber for at least 2 hours.

[0151] The pneumatic jaws of the tensile tester equipped with flat 2.54 cm square rubber-faced grips are set to have a gauge length of 2.54 cm. Sufficient tension (but less than 0.05 N) is applied to the sample to eliminate observable relaxation. The sample is stretched at a constant grip speed of 25.4 cm / min until the sample completely breaks. If the sample breaks at the grip interface or slippage within the grip is detected, the data is ignored and the test is repeated with a new sample and the grip pressure is adjusted appropriately. The samples are run in at least three replicates to illustrate the variability of the film.

[0152] The resulting tensile force-displacement data are converted to a stress-strain curve. Peak load is defined as the maximum stress measured when the specimen breaks and is reported in Newtons per centimeter of sample width (as measured parallel to the grip). The peak load for a given substrate is the average of the corresponding values ​​for each sample from that substrate.

[0153] Moisture Vapor Transmission Rate (MVTR) Test - The MVTR test method measures the amount of water vapor that permeates a membrane at a specific temperature and humidity. The transmitted vapor is absorbed by a CaCl2 desiccant and determined gravimetrically. Samples are evaluated in triplicate, along with a reference membrane sample of established permeability (e.g., Exxon Exxaire Microporous Material #XBF-110W) used as a positive control.

[0154] The test used a flanged cup machined from Delrin (McMaster-Carr catalog number 8572K34) and anhydrous CaCl2 (Wako Pure Chemical Industries, Richmond, VA; catalog number 030-00525).

[0155] The cup has a height of 55 mm, an inner diameter of 30 mm and an outer diameter of 45 mm. The cup is supplied with a silicone gasket and a cover containing three holes for thumb screws to completely seal the cup.

[0156] Fill the cup to within 1 cm of the top with CaCl2. Tap the cup on the counter 10 times to level the CaCl2 surface. Adjust the amount of CaCl2 until the headspace between the membrane surface and the top of the CaCl2 is 1.0 cm. Place the membrane across the opening (30 mm) on top of the cup and secure with a silicone gasket, retaining ring, and thumb screws. When properly installed, the sample should not wrinkle or stretch.

[0157] The membrane must completely cover the opening A of the cup, which is 0.0007065m 2 Weigh the sample assembly with an analytical balance and record to ±0.001 g. Place the assembly in a room at a constant temperature (40 ± 3 °C) and relative humidity (75 ± 3%) for 5.0 h ± 5 min. Remove the sample assembly and use Saran Cover and secure with a rubber band. Allow the sample to equilibrate to room temperature for 30 minutes, remove the plastic wrap, and reweigh the assembly, recording the weight to ±0.001 g. Absorbed moisture M a is the difference between the initial and final component weights. MVTR (in g / m 2 / 24h) is calculated as follows:

[0158]

[0159] Average the replicate results and round them to the nearest 100 g / m 2 / 24h, for example 2,865g / m 2 / 24h In this article, 2,900g / m 2 / 24h given, and 275g / m 2 / 24h at 300g / m2 / 24h given.

[0160] IX. Examples

[0161] Example 1 - Preparation of cycloSAP: Polymerization and crosslinking of acrylic acid in the presence of PAA

[0162] 10.54 g of distilled water and 105 g of a 2.5 wt% PAA solution (prepared by degrading a 2.5 wt% SAP gel) were charged to a 500 mL round bottom flange neck flask equipped with a 4-neck flange cap and a water-cooled condenser. The flask was cooled in an ice water bath. 43.18 g of acrylic acid (Cat#213040; 99.5%, low water, stabilized); Beantown Chemical) was added and stirred with a football-shaped magnetic stirrer. 33.08 g of sodium hydroxide (Cat#415413; 50% aqueous solution, Sigma-Aldrich) mixed with 1.64 g of distilled water was added in small aliquots, maintaining the temperature of the mixture between 17°C and 30°C. After this addition, the ice bath was removed. 0.335 g of polyethylene glycol diacrylate (Cat#455008; M n 700 Da; Sigma-Aldrich) was dissolved in 3.16 g of distilled water and added to the flask. The flask was purged with nitrogen for 1 hour by bubbling nitrogen through a stainless steel needle inserted through the septum into the stirring contents. 0.0113 g of L-ascorbic acid (Cat# A0278; reagent grade; Sigma-Aldrich) was dissolved in 0.5 mL of distilled water and added to the flask. 0.0518 g of potassium persulfate (Cat# 216224; ACS Reagent >99%; Sigma-Aldrich) and 0.0021 g of hydrogen peroxide (stable, 1%, Kroger, Topical Solution USP) were dissolved in 2.5 mL of distilled water and added to the flask within 1 minute of the L-ascorbic acid. The flask was observed and the stirrer was turned off when the viscosity increased enough to prevent the stir bar. The temperature was monitored and after the peak exotherm, the condenser was removed and the flask was sealed and placed in an oven at 60°C for 18 hours. The flask was removed, cooled, and the gelled contents were broken into approximately 1 cm round pieces by hand and spread onto an aluminum tray. The gel was dried in a fan oven at 120°C for 6 hours, removed, cooled, and ground using an IKA A11 Basic S1 grinder (IKA Works, Inc.). The ground powder was sieved, and the fraction between 150 μm and 500 μm was collected and placed in a controlled environment chamber at 73°F and 50% relative humidity for 24 hours.

[0163] The dimensions and values ​​disclosed herein are not to be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0164] The relevant parts of all documents cited in the detailed description of the present invention are incorporated herein by reference; the citation of any document should not be construed as an admission that it is prior art related to the present invention. When any meaning or definition of a term in this invention conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this invention shall prevail.

Claims

1. A method for providing an absorbent hygiene product (AHP) to a consumer, the method comprising: a. Providing a super absorbent polymer (SAP) prepared by the following steps: i. Separating the recovered SAP (rSAP) from the recovered AHP (rAHP); ii. degrading the rSAP into a material comprising polyacrylic acid (PAA), wherein the PAA has a weight average molecular weight of less than 5,000,000 g / mol; as well as iii. polymerizing acrylic acid in the presence of said PAA to form said SAP exhibiting an absorption against pressure (AAP) of at least 15 g / g; b. The SAP and the AHP member comprising a top sheet and a back sheet are combined to define the AHP; c. The AHP is provided in a package; as well as d. Communicating environmental information to the consumer to convey that the AHP comprises materials derived from recycled resources.

2. The method of claim 1, wherein the degradation comprises ultraviolet radiation in the flow system.

3. The method of claim 1, wherein the degrading comprises treatment in an extensional flow device. The method of claim 1 , wherein the degrading comprises microwave-assisted hydrothermal treatment. The method of claim 1 , wherein the degrading comprises sonication. The method of claim 1 , wherein the degradation comprises oxidative degradation.

7. The method according to any one of claims 1 to 6, wherein the SAP exhibits a -7 cm 3 Saline Flow Conductivity (SFC) in s / g.

8. The method of any one of claims 1-6, wherein the SAP exhibits an Absorption Against Pressure (AAP) of at least 20 g / g.

9. The method of any one of claims 1 to 6, wherein the acrylic acid is neutralized by 50 to 95 mol%.

10. The method of any one of claims 1 to 6, wherein the SAP is formed using a homogeneous solution polymerization process.

11. The method of any one of claims 1 to 6, wherein the SAP is formed using a heterogeneous polymerization process.

12. The method according to claim 11, wherein the multiphase polymerization process is selected from the group consisting of an inverse emulsion polymerization process and a suspension polymerization process.

13. The method of any one of claims 1 to 6, wherein the SAP is formed by polymerization in the presence of a difunctional monomer or a polyfunctional monomer.

14. The method according to any one of claims 1 to 6, further comprising surface cross-linking of the SAP.

15. The method of any one of claims 1-6, wherein the AHP comprises an absorbent core; and wherein the absorbent core comprises no more than 20% by weight absorbent fibrous material.

16. The method of any one of claims 1 to 6, wherein the SAP exhibits a -7 cm 3 Saline Flow Conductivity (SFC) in s / g.

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