NL8005908A - ABSORBENT PRODUCTS, METHODS FOR MANUFACTURING THEM AND PREPARATIONS CONTAINING SUCH PRODUCTS. - Google Patents

Description

1 ^ N.O. 29,490

Absorbent products, methods of manufacture, as well as preparations containing such products.

The present invention generally relates to non-disintegrating aqueous liquid absorbent products, methods and compositions.

The retention and / or removal of water or aqueous fluids, especially body fluids, is often accomplished through the use of absorbent-containing materials and articles made therefrom, lot of representative articles include diapers, incontinence pads, sanitary napkins , bibs, wound dressings and the like. In general, absorption is achieved through the use of cellulosic and modified cellulosic materials. When the intended use contemplates absorption of relatively large volumes of liquids, such as diapers, sanitary napkins and the like, the cellulosic materials are in the form of down or cotton wool. Particularly for these applications, the literature teaches the distribution of particulate materials, sometimes referred to as super absorbers, by the cotton wool or in certain areas thereof. The sagging and folding of the powder or particulate material encountered during transportation and storage has made these modifications of little value in practice. Also in the prior art, the leather has been found to modify the fibers in the cotton wadding sheet to significantly increase its absorbent capacity. These modifications have not avoided the need for a cotton wool sheet, which is voluminous by itself. Three films of absorbent polymers have been described, but they are generally rigid, inflexible and often fragile. Some films have been reported which are flexible, but methods of making such films employ an aqueous medium during or prior to extrusion with subsequent removal of water and do not constitute efficient or practical manufacturing operations attempting time consuming drying operations for avoid the removal of water. Absorbents are divided into latex, but these films are also subject to similar manufacturing concerns. Very thin absorbent films are coated on cellulose-like fibrous backsheets which, while applicable when present, such as in a diaper, having a top and backsheet, are subject to disintegration if not confined. In addition, absorbents are included in a foam matrix, which may be suitable for some applications, but not applicable for thin films or filaments. While some suggestion has been made of a water-insoluble polymeric sheet material, in a broad sense as an absorbent support, no actual product is disclosed or is known to be available.

According to the present invention, an aqueous liquid absorbent, non-disintegrating product is contemplated which contains a water-insoluble, practically non-swelling matrix of an elastomer or thermoplastic polymer with at least embedded a particulate, water-insoluble, but water-swellable therein. organic polymeric absorbent. By "water," as used herein, is meant to include aqueous fluids or liquids and is intended to include fluids such as saline, serum, blood, mucus, as well as other aqueous solutions or dispersions. The matrix, preferably from a thermoplastic elastomer polymer or thermoplastic polymer as defined hereinafter, is insoluble and practically non-swellable in aqueous systems and when wet resists breakage. The absorbent is selected from organic polymers which are insoluble in water but are swellable and which absorb many times their own weight in water or aqueous liquid. The organic polymer absorbents can be fully synthetic or can be selected from modified natural molecules, in particular modified polysaccharide, as described more fully below.

55 The product is flexible and when consisting of a thermoplastic elastomer or elastomeric polymer as matrix, also elastic, can withstand disintegration when wet, manufactured in the absence of water, can be made very thin while still very absorbent, 40 can be self-supporting or can be a coating, can be made in many 80 0 5 90 8 3 shapes and / or models. The shapes include film, monofilament, sheet, rope, tube, etc. and as a coating on a substrate, i.e., a film present on a support.

The product can be manufactured by various methods used in the manufacture of films, filaments and the like. The matrix polymer and the ten polymer absorbent include new compositions suitable for certain manufacturing methods and these compositions, as well as the use of these compositions for the manufacture of products are an aspect of the present invention.

The absorbent product has numerous applications and is suitable for use in protective coatings, sanitary napkins, wound dressings, diapers, bed pads, incontinence pads, packaging materials, agricultural cloths and the like. Certain articles of manufacture which can be made using the novel absorbent-containing polymer products are also an aspect of the present invention.

Brief description of the figures

Fig. 1 is a perspective view of an absorbent product in the form of a film in which an absorbent is dispersed.

Pig. 2 is a partial perspective view of an absorbent product in the form of an absorbent film on one surface of the film.

Fig. 3 is an enlargement of a partial section along 3-3 in FIG. 1.

30 Pig. 4 is an enlargement of a partial section along 4-4 in FIG. 2.

Pig. 5 is an enlarged partial cross-sectional view showing an embodiment of the invention when the absorbent product is in the form of a monofilament. Pig. 6 is a partial cross-sectional view showing an elongated core coated with the absorbent product.

Pig. 7 is a perspective view of a diaper using the absorbent product.

40 Pig. 8 is a view of a tampon made from

Q Λ Λ R Q Λ Q

4 the absorbent product.

Description of the Preferred Embodiments

The absorbent product of the present invention has particulate water-insoluble, however water-swellable organic polymeric absorbent dispersed on the surface or through a water-insoluble practically non-swellable matrix. In the preferred embodiments, the particles are dispersed in such a way that the absorbent is partially embedded in the matrix. By "partially embedded" is meant that the majority of the particles of the organic polymer absorbent are exposed to, or extend above, a portion of the particle surface over at least one surface of the matrix. While some individual particles may be fully embedded, they are generally in an abutting relationship with surface exposed particles. In an embodiment of the present invention, the particles are dispersed throughout the matrix, so that the particles are distributed in the matrix and are arranged on all surfaces of the matrix; in another embodiment, the particles are distributed on one surface of the matrix.

The foregoing can be better understood by reference to the figures. Figures 1 and 3 show a product in the form of a film 11, in which the absorbent particles 13 are dispersed through the matrix 12. It can be seen from the region "X" in Figure 1, that the underside of the film represents that absorbent has been exposed on the bottom as well as on the top surface. Figures 2 and 4 show a product in the form of a film 11a, in which 50 the absorbent is present on one surface of the matrix 12. The region "Y" in Figure 2 shows no absorbent exposed on the bottom surface. Fig. 5 illustrates absorbent dispersed throughout the matrix when the product is a monofilament 15 or a single stranded rope. Fig. 6 exposes a coated article 16 with product in the form of a coating on a core substrate 17 * The particulate absorbent materials are non-fibrous products in the form of fine, discrete particles, which cannot be formed into a fabric cloth. The particles can have different shapes such as 80 05 90 8 5 spherical, rounded, angular, pointed, irregular, fragmented and the like. They range in size from about 1 micrometer to 2 x 10 micrometers in diameter or diameter (largest diameter if not hollow) and are selected from those materials which are generally considered to be powders and those which are not powdered particulate material . The term "powder" is used to denote particles having a particle size from about 1 to about 1000 micrometers. When the particulate materials are dispersed through or embedded in the matrix, they are preferably in the form of a powder. When used in the form of powder and dispersed through it, the presence of the particles is not always readily apparent, the film or filament resembling a smooth film of the matrix polymer many times In the embodiment where the absorbent is present on a surface of the film, the particles are preferably non-powdered The approximate shape and geometry of the particles are retained as the material swells to provide bonding of the fluid therein.

The matrix is of an elastomer or thermoplastic polymer and preferably takes a form which is reachable by extrusion or, in the case of an elastomeric polymer, also by solvent casting. Therefore, the matrix 25 can be in the form of a film, sheet, filament, wire, rope, tube and the like. Since one of the advantages of the present invention is to make available a very thin material with a high absorbency, which is highly flexible, and in the case of a thermoplastic elastomeric matrix also highly elastic, the preferred embodiments envisage of the present invention the use of thin film or fine monofilament as matrix. The matrix can have a thickness ranging from about 25 µm to 1500 µm. It is generally intended that the thickness of the film be less than about 250 µm. » Usually the thickness will be more than 25 µm, preferably in the range of about 60 to 125 µm. When the product is in the form of a filament or rope, the cross-sectional dimension can be about 125 µm to about 1500 µm. The term "filament" or "monofilament" as used herein, q η n K o n q 6 is also intended for a monofilament thread or rope without regard to the cross-sectional dimensions. It is also contemplated to include a single strand that is not twisted or braided. When the product is in the form of a coating on a substrate, the dimensions may be similar to those of unsupported film, but will generally be thinner.

The product has a capacity to absorb water or an aqueous liquid in an amount of at least 10 times, preferably about 15 to 40 times or more, the weight of the absorbent in the product. Since the absorbent capacity of the product depends on the amount of absorbent in the product, the absorbent capacity of the product depends on the density or the weight of the absorbent contained in a given volume of the matrix. The particulate absorbent material is used in the product in the range of about 5 to 200 parts, preferably about 50 to 100 parts, per 100 parts by weight of the matrix polymer. The product efficiently absorbs water and aqueous liquids while maintaining flexibility or elasticity and flexibility depending on the matrix polymer and resists water loss when subjected to pressure.

The particulate absorbent materials to be dispersed in the matrix are organic polymers, which may be wholly synthetic organic polymers or which may be modified polysaccharides. In these absorbent polymers, hydrophilic groups form at least 25% and up to about 72% by weight of their molecular structure, and the polymeric network is slightly cross-linked to introduce limited water insolubility into the molecule. Suitable water-insoluble materials have a minimum average molecular weight per cross-linkage of about 13,000 and a maximum molecular weight per cross-linkage of about 276,000. These materials are usually discussed in the art as "hydrogels" or "hydrocolloid polymers" and further as "super absorbers." The preferred polymers have an acrylate group in their molecular structure. They can be fully synthetic acrylate 80 0 5 90 8 * * Polymers are either acrylic-modified polysaccharides, for example, acrylic-modified starch or acrylic-modified cellulose. "Acrylic polymers" or "polyacrylate" such as beer, includes not only 5 acrylic salts, but also those products, wherein part of the hydrophilic group is acrylamide, acrylic acid or acrylate ester, or the hydrophilic may also be provided by a different type of hydrophilic group such as sulfonate, oxide, etc., or by another type of polymer, as detailed below. Carboxymethyl cellulose after cross-linking also falls within a window of suitable absorbents The absorbent is usually a cross-linked natural or synthetic polymer, which would be soluble in water without the cross-linking, but which is slightly cross-linked by methods known in the polymer synthesis. The preferred absorbents are crosslinked polymers belonging to one of the following groups: fully synthetic acrylate polymer, acrylate modified starch, acrylate modified cellulose and crosslinked carboxymethyl cellulose.

When first considering the preparation of the fully synthetic absorbents, it is immaterial in the present invention whether the polymers to be used herein are prepared by adding an appropriate monomer or monomers and then polymerization, or by polymerization and then modification of part of the obtained polymer with repeating units. Thus, the polymers can be prepared by cross-linking a preformed water-soluble straight-chain polymer, by polymerizing a suitable monomer or monomer and comonomer and effecting both the polymerization and cross-linking, or by a suitable group in the polymer structure to record after polymerization is complete.

An example of the latter is sulfonation after polymerization to obtain polymers containing sulfonic acid units. In addition, if it is desired to have the salt form of the carboxylic acid or sulfonic acid group, the polymer may first be prepared as an acid, ester, amide or nitrile and the product as a whole or partially hydrolyzed.

o η n c o n o ö

The preferred synthetic absorbers are the acrylate type absorbers, which include not only the acrylate salts and acids, but also those represented in the literature, for example, U.S. Pat. No. 3 * 686,024- by the formula 1, wherein A is an alkali metal ion such as sodium or potassium or hydrogen, n is 0.5 to about 0.9, 1-n defines the degree of hydrolysis, and z is the number of more units between the cross-links.

The last type of acrylate absorbent can be prepared by polymerizing about 2 to 20% by weight of an aqueous solution of acrylamide with about 0.005 to 0.5 mol% (based on acrylamide) of a di-functional organic cross-linking agent, such as jTjlT'-methyl-15-bis-bisacrylamide soluble in the aqueous monomer system in the presence of free radical-forming catalysts to obtain a water-swellable cross-linked polyacrylamide and then partially hydrolyze in aqueous alkali to obtain 20 a cross-linked polymer with both carboxamide and alkali metal carboxylate groups, as more fully described in U.S. Patent 3,24-7,171. Also, a linear polyacrylamide can be cross-linked with a cross-linking compound such as Ν, Ν'-methylene bisacrylamide, 1,4-divinyl-25 benzene, diallylamine, Ν, Ν-diallyl methacrylamide and the like followed by hydrolysis.

A polymer with both a carboxamide and carboxylate group can also be prepared by copolymerizing acrylamide and an acrylic acid alkali metal salt in the presence of a cross-linking monomer, such as N, N-methylene bisacryl amide, in the presence of a catalyst system, such as equal parts of ammonium persulfate and β-dimethylaminopropionitrile, also as described in the aforementioned patent. The first type can be prepared by subjecting a mixture of a monovalent acrylic acid cation salt in water to the influence of cross-linking by high energy ionizing radiation, as described in more detail in U.S. Pat. No. 3,229,769 or by chemical cross-linking as described in British Patent Specification 710,330. A number of 8005908 9 suitable acrylic absorbents are commercially available, such as PEEMASORB (National Starch and Chemical), SANWET (Sanyo), "5388" designation (Goodrich), AQUA-KEEP (Mitsubishi), and is also available from the Dow 5 Chemical Company.

Another type of full synthetic absorbent is a cross-linked poly (alkylene oxide) with a molecular weight of at least 100,000, which can be prepared by contacting poly (alkylene oxide) with a suitable cross-linking agent in the presence of a free-radical forming catalyst in a liquid medium containing a solvent-non-solvent mixture for poly (alkylene oxide) in which the non-solvent part forms at least 35% by weight of the liquid medium at a temperature which is sufficiently high to effect cross-linking, as more fully described in U.S. Patent 3,956,224. Also, poly (alkylene oxide) can be cross-linked by ionizing radiation as described in U.S. Patent 3 * 264,202, or co-cross-linked with at least 20 another water-soluble polymer by exposing aqueous systems of the polymers to high energy irradiation to prepare cross-linked water-insoluble absorption polymers, as described in more detail in U.S. Pat. Nos. 3 * 957 * 605 and 3,898,143 *

Yet another type of fully synthetic polymeric absorbent is cross-linked polystyrene sulfonates prepared by a method known per se, for example, by copolymerizing styrene with a non-conjugated divinyl compound, such as divinyl benzene, in the presence of a polymerization catalyst, such as benzoyl peroxide , preferably in the presence of a suspension stabilizer, such as gelatin or polyvinyl alcohol, to prepare a polymer, which is then sulfonated by heating. The presence of concentrated sulfuric acid at a temperature of about 100 ° C.

Other suitable fully synthetic polymeric absorbers include the poly (N-vinylpyrrolidone) type disclosed in U.S. Patent 3,669,103, 40 polyurethane hydrogels disclosed in U.S. Patent No. 8005908, 3,939,105 sn 3, 939123 Still other suitable sorbents are suggested by those disclosed in U.S. Pat. Nos. 3,669,103, 3,966,679 and 4,102,340.

Another type of particulate absorbent material suitable for the present purposes is polysaccharide modified by hydrophilic chains grafted thereon. By "hydrophilic chains" is meant a polymer chain obtained from monomers which contain a water-soluble group 10 or which become water-soluble on hydrolysis, for example carboxyl, sulfone, hydroxyl, amide, amino, quaternary ammonium and hydrolysis products. Examples of such modified polysaccharides are disclosed in preferred U.S. Pat. No. 4,076,663. Polysaccharides have hydrophilic chains containing a carboxylate group alone or together with a carboreune or carbamide group bonded to a starch. or cellulose backbone. The modified polysaccharides are sometimes referred to in the literature as starch or cellulose graft copolymers; the preferred modified graft copolymers are polysaccharide acrylates or starch or cellulose acrylates. In these polysaccharide acrylates, the hydrophilic chain is bonded to the main chain of the cellulose or starch molecule by means of a carbon bond. Thus, a modified cellulose can be represented by formula 2, wherein L represents a hydrophilic chain of the general formula 3, wherein -C (= O) -A and -C (= 0) -B acid, ester, alkali metal or ammonium salt or amide groups represents, each R is independently hydrogen or a lower carbon number alkyl, r is an integer from 0 to about 5000, and s is an integer from about 0 to about 5000, and r + s is at least 500. A starch graft copolymer would be similar, but would contain a starch backbone. These polysaccharide-acry-35 are prepared, for example, by polymerizing a suitable polysaccharide with acrylonitrile or methacrylonitrile, with methyl or ethyl acrylate, with acrylic or methacrylic acid, or with acrylamide or methacrylamide, and then hydrolysis of the obtained polymer totally or partially with water containing 4-0 alkali. The polymer containing the carboxy 800590811 group can also be used. be prepared by polymerizing the alkali metal salt of acrylic or methacrylic acid. The methods for carrying out the graft copolymerization of ethylenically unsaturated chains on cellulose and starch are known.

Therefore, the grafting of the hydrophilic material onto a starch or cellulose backbone can be performed simultaneously with the formation of the hydrophilic polymeric material in an aqueous medium, because the peroxide catalyst used to copolymerize the different monomers. serene, forms a redox catalyst system in combination with a reducing agent and the like and thus also serves to effect chain transfer on the starch or cellulose backbone. Suitable reducing agents for this purpose are honorium ion, iron (II) ion, cobalt (II) ion, 15 (KHZ {2) 2S 2 Og, copper (II) ion and the like. The desired ions can be fed in the form of salts such as cerium ammonium nitrate, iron (H) ammonium sulfate and the like. Graft copolymerization of ethylenically unsaturated chains can also be accomplished by irradiation (ultraviolet-20, / or X-rays) or by heating in an aqueous medium in the presence of an emulsifying agent.

Powdered starch or cellulose fibers or pulp may be suspended in water containing a graft copolymerization catalyst system and the monomer or monomers added to the slurry and polymerized in situ at ambient temperature or above, depending on the catalyst used. In this manner, part of the hydrophilic polymer formed can also be physically incorporated into the polysaccharide backbone material during the polymerization process. The preparation of suitable starting materials for the practice of the present invention is also illustrated in U.S. Pat. Nos. 2,922,768, 5,256,572, 5,661,815, 3,955,099, 4,028,290, 4,076,665 and 4,105,055. Suitable starch polyacrylates 55 are commercially available such as SGP 502S (General Mills of Henkel) and STASORB (A.E. Staley).

Suitable polysaccharide acrylates are those in which the hydrophilic chain resting on the backbone ranges from about 10 wt% to about 90 wt%, preferably from about 40 to about 80 wt% of the graft copolymer. - fin η ς on a is more. The prepared polymers are dried at atmospheric pressure to expel water to produce a relatively stiff and brittle material which can be comminuted to a powder of a particle size of at least 1 micron. Preferably, the particles are no less than about 50 micrometers and no greater than about 1000 micrometers. Most preferably, they range from about 70 to about 325 microns.

A fourth type of absorbent suitable for the present invention is cross-linked carboxymethyl cellulose (CMC). Suitable cross-linked carboxymethyl cellulose products are those which can be prepared by heat treatment or wet cross-linking of the sodium salt of carboxymethyl cellulose with from about 0.5 to about 1 carboxymethyl group per each α / hyd hydrochloride unit. When cross-linking wet, reagents that are bifunctional with regard to cellulose such as epichlorohydrin can be used.

A representative process for preparing absorbent from the group of cross-linked carboxymethylcellulose-20 1 lose is heating the particulate form of water-soluble alkali metal salt of carboxymethyl cellulose with about 0.5 to about 1 carboxymethyl group per each anhydroglucose unit to a temperature between about 130 ° C and about 210 ° C, generally from several minutes to several hours, to obtain products which retain their physical appearance when dry, but when suspended in water exhibit reduced solubility and a new ability to absorb water for forming swollen gel particles, as described in more detail in U.S. Pat. No. 2,639,239. The particles, when not of the desired size, can be comminuted into a powder having a particle size preferably in the range of about 50 microns to 1000 microns. Suitably cross-linked carboxymethyl cell-55 lulose products are available as AQUASORB from Hercules.

The matrix in the absorbent product of the present invention contains an elastomer or a thermoplastic polymer. The elastomer is preferably a ther-40 plastic-elastomer block copolymer, but may also be natural rubber, synthetic rubber such as styrene-butadiene rubber and the like, which are elastic and have glass transition temperatures below about -10 ° C . The thermoplastic polymer is preferably a copolyester, but may also be polypropylene, pclyethylene, etc. The matrix can also be a mixture of certain elastomers and thermoplastic polymers, as described below.

The thermoplastic elastomeric block copolymers are those with a thermoplastic block, commonly referred to as 10 A blocks, and rubbery blocks, commonly referred to as B blocks. A suitable group of block copolymers includes those having thermoplastic terminal blocks and rubbery center blocks and designated A-B-A block copolymers. The term "A-B-A" block copolymers is intended to include all variations of block copolymers with rubbery midblocks and thermoplastic terminal blocks. Therefore, it is intended to include copolymers, sometimes referred to as A-B-G block copolymer, wherein G is also a thermoplastic terminal block, but a polymer different from A. It is also intended to include linear, branched and radial block copolymers. The radial block copolymers can be referred to as (AB ^ X, where X is a polyfunctional atom or molecule and where (AB) spreads from X in such a way that A is a terminal block. Another suitable group of block copolymers include wherein B forms a terminal block instead of a center block and are sometimes referred to as "AB" or "single" block copolymers The term "block copolymer" without qualification is intended to include both ABA and AB copolymers.

The thermoplastic "A" block is generally a polymer of alkenylarenes, preferably of styrene or styrene homologs and analogs such as α-methylstyrene, 5-tert-butylstyrene, 4-methylstyrene, 3,5-diethylstyrene, 3,5-di n-butylstyrene, 4- (4-phenyl-n-butyl) styrene, 2-ethyl-4-benzylstyrene, 4-cyclohexylstyrene, 4-n-propylstyrene vinyl toluene and the like.

The rubbery "B" block is a polymer of a conjugated aliphatic diene of 4 to about 6 carbon-40 atoms or of an olefin of 2 to about 6 carbon atoms on n on 14 in one. Suitable conjugated dienes include butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene and the like. The preferred dienes are butadiene and isoprene. Suitable olefins include ethylene, butene, propylene and the like.

In the radial block copolymer (AB ^ X, X may be an organic or inorganic polyfunctional atom or molecule and n is an integer with the same value as the functional group originally present in X. n is usually at least 3 and often 4 or 5 »In addition, it includes a more complex radial block copolymer system described in the article" New Rubber is Backed by Stars, "in Chemical Week, June 11, 1975» p. 55.

Suitable thermoplastic rubber block copolymers are prepared by stepwise solution polymerization of the components. The compositions and properties of block copolymers have been extensively described in the literature, such as, for example, "Thermoplastic Rubber (A-B-A Block Copolymers) in Adhesives" by J.T. Harlan et al., In "Handbook of

Adhesives "editor Irving Skeist, Van Nostrand Reinhold Co., New York, Second Edition (1977)" pp. 304-350; "Rubber-Related Polymers, I. Thermoplastic Elastomers" by WR Hendricks et al, in "Rubber Technology" Editor 25 Maurice Morton, Van Nostrand Reinhold Co., New York (1975), pages 5-5555 and U.S. patents 5,521,635, 5,519,585, 5,787,551 and 3,281,383, and for AB block copolymers, U.S. patents. 3 * 519,585 and 3,787,551.

In the appropriate block copolymers, the individual "A" block portion has a number average molecular weight of at least 6,000, preferably in the range of about 8,000 to 30,000, and the "B" block portion has a number average molecular weight, preferably in the range -35 ject from about 45,000 to about 180,000. The "A" blocks make up about 5 to about 50%, preferably about 10 to about 30% by weight, of the block copolymer. The number average molecular weight of the block copolymer is preferably in the range of about 75,000 to 40,000,000 for linear copolymers, and preferably in the 8005908 range of about 125,000 to 400,000 for radial copolymers.

Before the "A" "block is polystyrene and the" B "block is a butadiene polymer, the polymer can be referred to as an SBS or SB polymer, and when the" A "block is a styrene polymer and the" B Block an isoprene polymer, the polymer can be referred to as a SIS or SI polymer. Many of the block copolymers are in the

Cr) commercially available under trade names such as Kraton® 1102 and 1107 (both linear Shell Chemical Co.), Solprene® 418 and 420 (both radial) and Solprene® 3112 and 1205 (both single; Phillips Petroleum Co.).

Included within the scope of the thermoplastic elastomeric A-B-A or A-B block copolymers are certain blends of 15 A-B-A or A-B block copolymers as defined above and copolyesters as defined below. The blends contemplated to be included within the scope of the thermoplastic elastomeric ABA or AB block copolymer designation are those having substantially elastic properties and wherein the ABA or AB block copolymer is at least about 55 weight percent and the copolyester accordingly does not exceed 45% by weight.

The thermoplastic copolyester is primarily a polymer of at least two identifiable ester units which can be represented by formulas 4 and 5 wherein X and X 'are dicarboxylic acid cores and I and T' are aliphatic diol cores. The different ester units may arise from the condensation of (a) two different acids with the same diol, (b) two different diols with the same acid or (c) two different acids and two different diols. By "co-polyesters" are meant random and segmented polyesters, as well as copolyesters with alternating units formed by copolymerization. By "random" is meant that the ester units are usually not in a particular pattern. "Segmented" means that there is a polymer block of a given ester unit joined with a polymer block of another ester unit by an ester bond. In general, an ester unit of the copoly-40 ester is highly crystalline and considerably less crystalline or even non-crystalline.

Among the aromatic and aliphatic dicarboxylic acids suitable for copolyesters are terephthalic, isophthalic, oxalic, maleic, succinic, glutaric, adipic, turmeric, azelaic, sebacic, and the like.

Aliphatic diols used in the polyesters include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, tetramethylene glycol, trimethylene glycol, and the like. Preferred aliphatic diols are straight chain alkylene diols having 2 to 4 carbon atoms.

As representative copolyesters, the following can be mentioned: Poly (ethylene terephthalate-co-ethylene azelate), poly (ethylene terephthalate-co-butylene adipate), poly (ethylene terephthalate-co-1,2-propylene terephthalate), poly (butylene terephthalate-co-butylene isophthalate), poly (ethylene terephthalate-co-ethylene sebacate), poly (ethylene terephthalate-co-tetramethylene terephthalate), polyethylene terephthalate-coethylene adipate), poly (ethylene te-20 rephthalate-co-trimethylene terephthalate) and the like, including polyesters described on pages 77-80 of "Encyclopedia of Polymers, Science and Technology," Vol.

XI, John Wiley & Sons (1977). Random copolyesters can often be identified by the relative amounts of the constituent diols and acids as in U.S. Patent 5,699,189. Such polyesters also fall within the scope of a suitable matrix polymer.

The copolyesters usually have a thermal softening temperature below about 225 ° C. The preferred copolyesters have an extrusion temperature within the range of about 165 to about 219 ° C. Suitable copolyesters can be characterized by a torque property, which can be measured by use in a recording torque dynamometer (Plasti-Corder EPL-V750 manufactured by C.W.Brabender Co., Hackensack, N.J.). When processed at 75 rpm at 216 ° C using a REE 6 mixing head, suitable copolyesters will exhibit a torque value of less than about 10,000 meters grams, preferably in the 8005908 range from about 200 to about 600 meters grams at this temperature. These values can be converted to poisen by applying the following formula torque x 388 - = poise o.p.m.

Thus, when expressed in poisen, the esters will exhibit coupling properties of less than about 5200 poise, preferably about 1000 to 3600 poise. Generally, the copolyesters having the aforementioned suitable properties are in the number average molecular weight range from about 20,000 to 200,000, preferably about 30,000 to 75,000.

Copolyesters can be prepared by conventional condensation polymerization methods, such as esterification of dicarboxylic acids or acid derivatives, for example esters or acid halides, with diols, usually at temperatures in the range of about 150 to 250 ° C, but sometimes at 280 ° C to form a copolyester polymer. The reaction is usually carried out in the presence of excess diol to compensate for loss of diol during the co-distillation with liberated reaction water; the reaction can be carried out in the presence of catalysts.

Another method of carrying out the reaction is ester exchange using diols with dicarboxylic acid diesters or using dicarboxylic acids with diol diesters. These and other methods are described, for example, in "Encyclopedia of Polymer Science and Technology", Vol. II, pp. 88-113 *

Segmented copolyesters, suitable as matrix materials, can also be prepared using similar methods employed in a stepwise fashion. In a representative method, an alkyl diester of one or more low molecular weight dicarboxylic acids is heated with a suitable long chain and excess short chain diol in the presence of a catalyst at about 150 to 200 ° C while distilling the exchange formed low molecular weight alcohol. Heating is continued until alcohol development is complete to obtain a very low molecular weight prepolymer which can be converted to a high molecular weight 8005908 18 segmented copolyester by heating the prepolymer with a long chain diol and the excess diol short chain distillation, preferably at reduced pressure and elevated temperatures in the presence of antioxidants. Representative preparations can be found in U.S. Pat. Nos. 3,832,314 and 3 * 952,326. Suitable polymers are also commercially available under the VPE names from Goodyear Tire & Rubber Company, under KODAR® names from Eastman Chemical Company and DYVAX® names from E.I. du Pont de Nemours & Co., Ine.

Inside the. Copolyesters include certain blends of copolyesters and A-B-A or A-B block polymers.

In such blends, which are blends having substantially 15 plastic film-forming properties, the block copolymer ranges from about 75,000 to 200,000 for linear copolymers and 125,000 to 400,000 for radial copolymers. The blends falling within the scope of the copolyesters are those in which the copolyester component 20 is the major component by 55 to 95% by weight and the block copolymer component is the minor component by 45 to 5% by weight.

The absorbent product of the present invention can be prepared by various methods, none of which require the use of an aqueous environment, thereby eliminating the need for extensive drying methods. The preferred method may depend on the particular absorbent used or when it is desired to have the absorbent on only one surface.

When the absorbent is stable to the extrusion temperature of the matrix polymer and / or when the particulate absorbent is to be dispersed through the matrix rather than on a surface, the product can be manufactured by extrusion. Some extruders which are extrudable are polyacrylate as defined above, sulfonated polystyrene, poly (alkylene oxide) and the like.

When using the extrusion method, the ma-40 trix polymer and the absorbent polymer are thoroughly mixed with each other and extruded. Premixing is highly desirable when there is a high filling of the absorbent. When the level of the absorbent to be dispersed is low, i.e., about 5 to 15 parts by weight per 100 parts by weight of the matrix polymer, the components can be fed directly to the extruder without premixing. It is preferred, however, that the absorbent polymer and the matrix polymer be premixed with heating to a uniform dispersion of the particulate absorbent in the molten matrix polymer and the resulting uniform mixture be granulated, ground, flaked or otherwise after cooling. size is reduced, which is suitable for feeding to an extruder, or the molten mixture can be fed directly to the extruder and the extrusion is carried out to obtain a non-disintegrating absorbent product, which a water-insoluble, substantially non-swelling matrix of a thermoplastic or a thermoplastic elastomer polymer containing particulate dispersion thereby dispersed, however, water-insoluble, but water-swellable, organic polymeric absorbent in the form of a film, filament, tube or other extrudable shape. In this method, the absorbent is preferably in the form of a powder, ie a particle size of 1000 microns in diameter or less. The premixing can preferably be carried out within the temperature range of about 66 to 135 ° C. When the matrix polymer is thermoplastic, the range is about 107 to 135 ° C. The extrusion becomes JO at. preferably conducted in a temperature range from about 150 to about 232 ° C. When it comes to the extrusion of a thermoplastic polymer, it has been found that although not essential, the addition of a minor amount, for example about 5 to about 10 parts by weight per 100 parts by weight of a thermoplastic matrix polymer of an ABA block polymer, is desirable to facilitate the extrusion. to ease. The extrusion method is particularly suitable for obtaining a non-disintegrating absorbent product in the form of very thin films and monofilaments. The product will contain the absorbent dispersed by it - 8005908

C. \ J

as shown in Figs. 1, 3 and 5

The extrudable compositions, which are preferably formed by premixing and contain (a) thermoplastic elastomer matrix polymer or thermoplastic matrix polymer and (b) 3 particulate polymer absorbent, are an aspect of the present invention. The composition may contain minor amounts of products, which are generally added to extrudable film-forming compositions. Examples of such additives are antioxidants such as 2,5-di-tert-amylhydroquinone, zinc salts of alkyl dithiocarbamates; fillers and pigments such as zinc oxide, titanium dioxide, calcium carbonate and the like. In addition to the usual additives, small amounts of wetting agents can be included, which facilitate the initiation of the aqueous fluid uptake by the absorbent. In the compositions, in which the matrix polymer component is thermoplastic (without elastomeric properties), a very small amount, up to about 10%, of the thermoplastic elastomeric block. Copolymer (A-B-A or A-B block copolymer) described for the blend compositions, are incorporated without substantially altering the properties of the plastic matrix polymer. Generally, the extrudable compositions contain about 5 to about 200 parts of polymeric absorbent per 100 parts by weight of the matrix polymer.

Preferred extrudable compositions are those containing synthetic polyacrylates and a thermoplastic elastomer A-B-A or A-B block copolymer matrix polymer or a synthetic polyacrylate and a copolyester-matrix polymer. As indicated above, the term "acrylate" includes polymers containing an acid ester, amide or salt acrylate group or mixtures thereof.

The polyacrylate and block copolymer compositions contain about 5 to about 200 parts of acrylate polymer per 100 parts of A-B-A or A-B block copolymer, preferably about 20 to 100 parts. The polyacrylate and copolyester formulations contain from 5 to about 500 parts of an acrylate polymer, preferably from about 50 to 150 parts per 100 parts of copolyester.

The extrudable preparation can also be used 8005908 21 using a hot melt casting technique. Thus, instead of cooling the molten mixture and granulating for extrusion, the molten preparation can be cast to produce a free film or a coating on a substrate.

Another method in which a product can be uniformly dispersed throughout the matrix is particularly suitable for the preparation of elastomeric film. This method contemplates a solvent casting composition in which the rubber or the thermoplastic elastomer, polymeric absorbent and antioxidants are dispersed in an organic solvent. The composition is poured onto a suitable surface using conventional methods, the solvent / evaporated to obtain an elastic film with absorbent polymer evenly dispersed throughout. Suitable solvents for the casting compositions are generally aromatic hydrocarbons or alkanes, especially toluene, xylene, benzene, heptane and the like. The preparations usually also contain antioxidants. Common antioxidants include zinc dibutyl dithiocarbamate, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone and the like.

Absorbent products in which the particulate absorbent is primarily supported by the matrix on a surface can be prepared by a process in which the matrix is first formed and the absorbent is combined thereon. This method is applicable in the preparation of the absorbent product 30 regardless of the chemical nature of the absorbent polymer used.

One modification of this general method aims at the association of the absorbent polymer practically at the time of matrix formation. In this method, the matrix polymer is extruded into some intended form, generally a film or a monofilament, and the absorbent is applied to the surface of the molten sheet or filament. The absorbent is partially embedded in the still molten 4-0 surface upon contact and is permanently embedded in cooling. The 8005908 22 operation can be performed by modifying the extruding equipment in known manner. For embedding in a film, the particulate absorbent polymer can be spread or sprayed onto the film as it exits the nozzle. For recording on the surface of a filament, a similar manner can be used using a nozzle adapter. .

In another method, a preformed matrix is used and a solvent coating composition is used, which has a solvent effect on the surface of the matrix, allowing partial embedding of the absorbent simultaneously with adhesion and the effect becomes permanent made by passing the material through drying ovens. In one of these modifications, a non-pressure sensitive adhesive composition is layered on the surface of the extruded film or the extruded filament, and the absorbent is applied to the surface of the solvent-wetted film beforehand to the passage through 20 ovens. In such a method, any adhesive composition to be coated with an organic solvent can be used. In a second modification of this general method, a pressure sensitive adhesive coating composition is coated on the face of the extruded film or the extruded filament, the solvent is removed from the coated film or filament and the absorbent is removed. applied to the surface.

The absorbent product prepared by any of the aforementioned methods, in particular the products in the form of films, can be further modified to form a discontinuous flat surface. Such a surface may be cross-linked or may have relief patterns of elevations and depressions. Cross-linked films are of special value for better fluid uptake speed. The production of absorbent products from films with discontinuous surfaces can be carried out by methods known per se.

Example I

An extrudable preparation of 100 parts by weight of a 40 styrene-isoprene-styrene (SIS) block copolymer (Kraton 8005908 23 1107) and 100 parts by weight of polyacrylate powder (Permasorb AG) are thoroughly mixed at about 121 ° C and the resulting molten mixture is cooled, granulated, and the granules are extruded at about 177 ° to form a 75 µm thick film with absorbent dispersed therethrough. The film product swells immediately on contact with water.

Example II

An extrudable preparation of 100 parts by weight of styrene-10 butadiene-styrene (SBS) block copolymer (Kraton 1102) and AO parts by weight of polyacrylate powder (Sanwet) are mixed, granulated and extruded as described in Example I to form a film with a thickness of 250 µm with the absorbent dispersed through it. The film products 15 absorb water quickly.

Example III

An absorbent formulation suitable for solvent casting film-forming and having the following composition: SIS rubber (kraton 1107) 100 parts by weight of 20 starch polyacrylate (SPG 5025) 100 parts by weight of zinc dibutyl dithiocarbamate 5 parts by weight of 2.5-di-tert-butylbydrocbinone 1 part by weight 50 percent solids in toluene is prepared by dissolving the rubber and antioxidants in toluene and then stirring the starch polyacrylate absorbent therein. The preparation is poured onto a silicone liner at a dry coating weight

O

of 67.6 g / m and the solvent is then removed to obtain an absorbent film product with good absorbent properties.

Example IV

A preparation suitable for solvent casting with the following composition: S-I rubber (Solprene 311) 100 parts by weight polyacrylate (Permasorb-AG) 30 parts by weight zinc butyl ditbiocarbamate 5 parts 2.5-di-tert-butyl hydrocroconone 1 part .dl solids in toluene 50 percent is prepared by dissolving the rubber and the antioxidants in 40 toluene and then stirring in the polyacrylate absorbent. The preparation is poured onto a silicone liner with a dry coating weight of 101.4 g / m and the solvent is then evaporated to obtain the absorbent film product.

5 Example V

In a similar manner as described in Examples III and IV, an absorbent film product of 75 µm is obtained by pouring the following film-forming preparation: 10 SBS rubber (Carton 1102) 100 parts of cross-linked carboxymethyl cellulose 20 parts of zinc dibutyl dithiocarbamate 5 parts of 2,5-di-tert-butylhydroquinone 1 part of solids in toluene 50 percent 15 The film rapidly absorbs free water on contact.

Example VI

A 25 µm thermoplastic elastomeric film of SIS block copolymer (Kraton 110?) Is solvent coated with the following pressure sensitive adhesive composition: SIS rubber (Kraton 1107) 50 parts by weight SI rubber (Solprene 5 ^ 1) 50 parts of adhesive resin (Wing-tack 95) 80 parts of zinc dibutyl dithiocarbamate 2 parts of 25 2,5-hi-tert-butylhydroquinone 1 part

The adhesive composition is applied in sufficient amounts to deposit the pressure sensitive adhesive on the film in an amount of 55.8 g / m and the coated film is passed through drying ovens maintained at 121 ° C. After the film is thoroughly dried, a cross-linked carboxymethylcellulose absorbent (Permasorb 10, National Starch) is uniformly applied to the surface of the film to produce a non-disintegrating absorbent product with the absorbent 55 evenly distributed over one surface. of it. The absorbent product exhibits immediate absorption of aqueous liquid upon contact with an aqueous system. (Wing-tack 95 is a predominantly polymerized piperylene isoprene adhesive resin from Goodyear Tire% 40 Rubber).

80 0 5 90 8 25 ""

Example YII

A 25 µm thermoplastic elastomer film of SIS block copolymer (Kraton 1107) is coated with the following adhesive composition in an amount of 5 33.8 g / m2: SIS rufrber (Kraton 1107) 100 parts resin (Amoco 18-290 ) 75 parts by weight of zinc dibutyl dithiocarbamate 2 parts by weight of 2,5-di-tert-butylhydroquinone 1 part by weight of 10 solids in toluene 50 percent (Amoco 18-290 is poly (α-methylstyrene) resin from Amoco Chemical Co.).

On the surface of the freshly coated film, a particulate starch polyacrylate absorbent (SGP 15 5025, General Mills of Henkel) is applied in a substantially monomolecular layer and the resulting film is passed through drying ovens (kept at about 121 ° C) , guided to remove the toluene solvent and obtain an absorbent film product containing absorbent 20 on one major surface thereof. The obtained film shows immediate absorption when contacted with a saline solution.

Example VIII

Radial S-I-S block copolymer is extruded at 177 ° C as a film and a granular starch polyacrylate absorbent (Stasorb, A.E. Staley Company) is applied to the surface of the molten sheet. The sheet is cooled to obtain a non-disintegrating absorbent product containing absorbent on one major surface thereof. The product shows good absorbent properties.

Example IX

The preparation of Example I is prepared for extrusion and extruded to form a 55 µm diameter monofilament. The monofilament absorbs water on contact with water and forms a swollen thread.

Example X.

An extrudable preparation of 100 parts by weight of a poly (ethylene terephthalate-co-ethylene-azelate) copolyester 40 (VPE 5571) and 40 parts by weight of polyacrylate powder (Permasorb AG) 8005908 2b are mixed thoroughly at 177 ° C and The molten mixture obtained is cooled, granulated and the granules are fed to the funnel of an extruder simultaneously with a minor amount of a commercially available styrene-isoprene (SI) block copolymer (Solprene 311 »Phillips Petroleum Company) and extruded at a temperature of about 177 ° C to form a film with a thickness of about 125 µm, whereby the absorbent is dispersed. The film immediately swells on contact with water at room temperature.

Example XI

In another operation, 75 parts by weight of PE 5571? 25 parts by weight of Solprene-311 and 50 parts by weight of Permasorb AG are thoroughly mixed, granulated and extruded in a similar manner to form a film having a thickness of about 75 µm? in which the absorbent is evenly dispersed. The film absorbs water quickly.

Example XII

In another similar process, 100 parts of 20 poly (ethylene terephthalate-co-1,2-propylene terephthalate) co-polyester (VPE 4-709 »Goodyear Tire & Subber Company) and 4-0 parts of polyacrylate absorbent (Sanwet, Sanyo Company) mixed together at about 177 ° C, the molten mixture is cooled, granulated and extruded simultaneously, not about 5 parts of styrene-isoprene-styrene (SIS) block copolymer (Eraton 1107) to produce a film of thickness of about 50 µm in which the polyacrylate absorbent is dispersed. The film immediately swells on contact with an aqueous salt solution.

Example XIII

According to another similar method, 100 parts of VFE-5571 and 2 parts of Permasorb AG are mixed together under heating, granulated and extruded to produce a film in which absorbent is evenly dispersed and suitable for use in small absorbent bandages.

Example XIV

A cotton fabric is coated with solvent with the following pressure sensitive adhesive composition: 4-0 8005908 27

Component parts

Kraton 1107 50

Solprene 311 50 adhesive resin (Wingtack 95) 80 3 zinc dibutyl dithiocarbamate. 2 2.5-di-tert-butylhydroquinone 1 (Wingtack 95 is a substantially polymerized piperylene and isprene available from Goodyear Tire & Rubber).

The adhesive composition is applied in an amount sufficient to deposit a pressure sensitive adhesive on the fabric in an amount of 101.4 g / m and the resulting coated film is passed through drying ovens which are placed at 150 ° C kept. After the coated fabric has dried thoroughly, a cross-linked carboxymethylcellulose absorbent (Aquasorb, Hercules) is evenly applied to the surface of the film to produce a non-disintegrating absorbent product with the absorbent evenly distributed on one surface of it. The absorbent product exhibits immediate absorption of aqueous liquid upon contact with an aqueous system.

Example XV

A polyester (VPE 5571) film with a thickness of 25 µm is coated with the following adhesive preparation: 25 Component parts of SIS rubber (Kraton 1107) 100 resin (Amoco 18-290) 75 zinc dibutyl dithiocarbamate 2 2.5-di-tert-butylhydroquinone Solids in toluene 50% (Amoco 18-290 is poly (α-methylstyrene) resin available from Amoco Chemical Co.).

On the surface of the freshly coated film, a particulate starch polyacrylate absorbent (SGP 35 5025, General Kills of Henkel) is applied in a substantially monomolecular layer and the resulting film is passed through drying ovens (maintained at about 121 ° C) to remove toluene solvent and obtain an absorbent film product with absorbent on one major surface thereof. The resulting film shows immediate absorption upon contact with saline.

Example XVI

VPE 5571 is extruded at 177 ° C using about 5 wt% Kraton 1107 to form a film and granular starch polyacrylate absorbent (Stasorb, A.E. Staley Company) on the surface of the molten sheet. The sheet is cooled to obtain a non-disintegrating absorbent product containing absorbent on one major surface thereof. The product shows good absorbent properties.

Example XVII

The preparation used in Example I is extruded to form a monofilament with a diameter of about 25 µm. The monofilament readily absorbs water upon contact with water to form a swollen thread.

The absorbent products of the present invention are suitable for many articles where absorption of aqueous liquid is desired, such as diapers, bandages, pillows, blankets, packaging materials and the like. The products are particularly adapted for use in the manufacture of certain articles.

The absorbent product in the configuration of a film can be used as an absorbent layer in a new thin diaper with less mass than a fabric diaper but with a high absorbency. For such use, the absorbent film product may be a product with the absorbent dispersed through the film or with the absorbent dispersed on one surface of the film. When the film product contains absorbent dispersed throughout the film, it is desired that the product be provided with a liquid-permeable backsheet 21 and a liquid-impermeable backsheet 22 and assembled by conventional diaper forming methods 20 such as indicated in Fig. 7 · The front sheet may be of any conventional liquid-permeable cellulose material. The backing sheet may be of any conventional liquid impermeable material, such as polyethylene 40 or a copolyester or thermoplastic elastomer film, such as 8005908 29 as used in the absorbent product, the latter thermoplastic elastic film also being described in the U.S. patent 4-.024-.312. A diaper with a stretchable absorbent layer and elastic backing by using a thermoplastic elastomer block copolymer as both the matrix and the backing allows the diaper to be thin and provided with a specific surface area that is sufficient only for a comfortable wear around provide the carrier. The expansion of the absorbent product, which takes place during use, will be accompanied by a simultaneous expansion of the backing, the expansion only taking place in sufficient amounts to adjust the swollen absorbent product.

When the film product is a product containing an absorbent dispersed on one side of the film, the film product can perform both the function of absorbent layer and backing layer, the side of the film not carrying the absorbent serving as back layer. The absorbent film in the latter embodiment will generally be of a heavier caliber, which can be easily determined by one skilled in the art.

An absorbent film product dispersed throughout the matrix can also be used as a coating on a substrate. In such an application, an extrudable preparation on a film-forming solvent casting composition, as described above, is extruded or cast onto a substrate film in a conventional manner. In addition to coated films, coated filaments can be made by extrusion coating, where a filament or filament substrate carries the absorbent as a coating, as shown in Figure 6.

The absorbent product with absorbent dispersed through the matrix can be extruded through a die provided with a cylindrical opening to produce a wire or flexible rod. By using a crosshead nozzle, a support member in the form of a strand, monofilament or wire can be coated with a composition, such as any of the above described compositions, to obtain a coated core 4-0 substrate that serves as the basis of a thin 8005908 tampon 25 as illustrated in Fig. 8. Such a tampon may be of conventional length, but has a diameter in the range of about 0.125 to 1.0 cm. The advantage of a tampon made with the absorbent product of the present invention is the thin quality of the article for providing ease of insertion, while still having the same or greater absorbency compared to a tampon of much larger dimensions.

Example XVIII

A preparation consisting of a 30 percent solids dispersion in toluene of 100 parts of Kraton 1107 and 100 parts of starch-acrylate absorbent (hydrolyzed starch-acrylonitrile graft copolymer) is prepared by dispersing Kraton 1107 in toluene. and then quickly stir in starch acrylate absorbent. The preparation is poured onto silicone paper and the solvent is evaporated to obtain a flexible elastic absorbent film of about 250 µm thickness, which absorbs more than 10 times its weight in water, and becomes a gelatinous rubbery film.

The film is sandwiched between a water-permeable diaper front face and a water-impermeable diaper back face to create an absorbent diaper having a thickness of about 500 to 625 µm compared to a thickness of about 3500 ^ um for a usual diaper.

Example XIX

The extrudable preparation of Example I is extruded intermittently through a crosshead nozzle on a cotton skein to form intermittently coated lengths, each coated length having a length of about 4.3 cm and a diameter of about 0.5 cm. After the completion of the extrusion, the strand is cut into the uncoated portion to form thin tampons.

Example XX

The film product of Example X is sandwiched between a water permeable diaper front surface and a water 40 non-permeable diaper back surface to produce an 8005908 31 absorbent diaper having a thickness of about 500 to 623 µm compared to a thickness of about 3500 / i ™ for a usual diaper.

Example XXI

The extrudable preparation of Example X is extruded intermittently through a crosshead nozzle on a cotton skein to form intermittently coated lengths, each coated length being about 4.3 cm with a diameter of about 0.5 cm.

After completion of the extrusion, the strand is cut into the uncoated portion to form thin tampons.

8005908

Claims (20)

A flexible, non-disintegrating absorbent product characterized by a water-insoluble, practically non-swelling matrix of a polymer with thermoplastic properties such as (a) a thermoplastic-elastomer block copolymer and (b) a thermoplastic copolymer. polyester polymer, which matrix contains a uniformly dispersed, particulate, water-insoluble, water-swellable organic polymer absorbent. The product according to claim 1, characterized in that the absorbent has a particle size of about 1 micron to about 2 x 10 microns in cross section and contains about 5 to about 200 parts per 100 parts by weight of matrix polymer. 15 Product according to claim 1 or 2, characterized in that the product is in the form of a film. Product according to claim 1 or 2, characterized in that the product is in the form of a monofilament or thread. 20 A product according to claim 1, characterized in that the matrix polymer is a thermoplastic elastomer ABA or AB block copolymer or a mixture thereof, wherein A is an alkenyl arene polymer block and B is a polymer block of a conjugated aliphatic diene with a small number of carbon atoms or an aliphatic olefin having a small number of carbon atoms, and wherein the polymer absorbent is a synthetic acrylate polymer or a modified polysaccharide. 6. Product according to claim 1, characterized in that the matrix polymer is a thermoplastic copolyester of at least two different ester units, each unit being a condensation product of a dicarboxylic acid and an aliphatic diol and wherein the polymer absorbent is a synthetic acrylate polymer Or is a modified polysaccharide. The product according to claim 1, characterized in that the particulate polymeric absorbent is embedded at least in part in the matrix. 8. Method in a non-aqueous medium for the preparation of a flexible product with a water-insoluble, practically non-swellable matrix of a polymer with thermoplastic properties, which has an evenly dispersed, particulate, in water-insoluble, water-swellable synthetic organic polymer absorbent, characterized in that 1. the matrix polymer and the polymer absorbent are thoroughly mixed to a substantially homogeneous mixture and 2. the mixture is extruded. 9. Process according to claim 8, characterized in that a thermoplastic elastomer ABA or AB block copolymer or a mixture thereof is used as polymer with thermoplastic properties, in which A an alkenylarene polymer block and B a polymer block of a conjugated aliphatic diene with a small number 15 represent carbon atoms or an aliphatic alkene with a small number of carbon atoms, and wherein the polymer absorbent is a synthetic acrylate polymer. 10. Process according to claim 8, characterized in that a copolyester of at least two different ester units is used as the polymer with thermoplastic properties, each of which is a condensation product of a dicarboxylic acid and an aliphatic diol, and wherein the polymer absorbent is a synthetic acrylic polymer. Process according to claim 8, characterized in that a film is used as the product. Process according to claim 8, characterized in that the product used is a monofilament. 13. A method in a non-aqueous medium for the preparation of an absorbent film having elastic and thermoplastic properties and with a water-soluble, substantially non-swelling matrix of a thermoplastic elastomer polymer, which has an evenly dispersed, particulate, water-insoluble, water-swellable organic polymeric absorbent, characterized in that 1. the thermoplastic elastomeric polymer and the polymeric absorbent are thoroughly mixed in an organic solvent preparation and 8. o. pour the preparation. 14. Methods according to claim 13, characterized in that an ABA or AB block copolymer or a mixture thereof is used as the thermoplastic elastomer polymer, wherein A is an alkenylarene polymer block and B is a polymer block of a conjugated aliphatic diene with a small carbon atoms or an aliphatic alkene with a small number of carbon atoms, and wherein the polymeric absorbent is a synthetic acrylate polymer, a cellulose acrylate polymer, a starch acrylate polymer and / or a cross-linked carboxymethyl cellulose. 15. Extrudable preparation suitable for the manufacture of an absorbent product with elastic and thermoplastic properties, characterized by the presence of (a) a thermoplastic elastomer polymer, containing an ABA or AB block copolymer or a mixture thereof, wherein A is an alkenylarene polymer block and B represent a polymer block of a conjugated aliphatic diene with a low carbon number or an aliphatic olefin with a low carbon number, and (b) a synthetic acrylate polymer. 16. Extrudable preparation suitable for the preparation of a thermoplastic absorbent product, characterized by the presence of (a) a copolyester of at least two different ester units, each unit being a condensation product of a dicarboxylic acid and an aliphatic diol, and (b) a synthetic acrylate polymer. 17. A film preparation suitable for manufacture by casting an absorbent film having elastic and thermoplastic properties, characterized by the presence of a (a) thermoplastic elastomer polymer containing an ABA or AB block copolymer or a mixture thereof wherein A represents an alkenylarene polymer block and B a polymer block of a conjugated aliphatic diene having a small number of carbon atoms or an aliphatic olefin 40 containing a small number of carbon atoms, (b) a polymeric absorbent such as a synthetic acrylate polymer, cellulose acrylate polymer, starch-acrylate polymer and / or cross-linked carboxymethyl cellulose, and (c) an organic solvent. 18. Thin absorbent article, characterized by the presence of an absorbent product according to claim 5 or 6 provided on the front side with a liquid permeable sheet. Product according to claim 18, characterized in that the absorbent product is also provided with a backing layer of a liquid-impermeable sheet. Tampon, characterized by the presence of an absorbent product according to claim 5 or 6. ******* 8005908