EP0000775A1 - Water vapour absorbent and permeant flat rubber product and a method for its manufacture - Google Patents

Abstract

The invention relates to a fabric made of natural or synthetic rubber or a rubber-like polymer that is improved in water vapor absorption capacity and permeability. These flat structures, which are present, for example, as self-supporting films or coatings on substrates, contain a uniformly incorporated additive composed of particles made from at least one swellable, modified polymer. These swellable, modified polymers are in particular at least about 50% by weight water-insoluble; They preferably include swellable, modified carbohydrate derivatives, such as starch or cellulose ethers crosslinked with the aid of thermal energy, radiation or an additional chemical compound. In a process for the production of such sheetlike structures, the particles of at least one swellable, modified polymer are added to a rubber-containing base material and are distributed uniformly therein, and the mixture is then spread, or otherwise deformed or solidified, if necessary with foaming. The fabrics according to the invention are particularly suitable for those areas of application in which body fluids, such as e.g. Sweat, occur. These include, for example, rubberized textiles, shoe upper materials, shoe insoles, carpet backing materials or hygiene articles.

Description

The invention relates to a sheet made of natural or synthetic rubber or a rubber-like polymer which is improved in water vapor absorption capacity and permeability, and a method for producing these sheets.

Sheets made of rubber are used in various technical fields. B. the manufacture of rubber shoes, sponge and cellular rubber, rubberized fabrics (e.g. raincoats, tents, or carpet backing) or immersed rubber goods (e.g. surgical gloves). Processes for the production of such flat structures, which are usually produced as self-supporting foils or as multilayer (e.g. consisting of cover and carrier layers) flat structures, have long been known (see e.g. Ullmann's Encyclopedia of Technical Chemistry, Verlag Urban & Schwarzenberg - Munich, 1957, volume 9, 3rd edition, keyword "rubber", in particular pages 351, ff, 365 ff and 375 ff or S. Boström, rubber handbook, Verlag Berliner Union - Stuttgart, 1961, volume 4, 1. Edition, in particular pages 172 ff and pages 263 ff). If these fabrics are used in particular under physiological conditions, for example as a coated textile or as a shoe and in the form of a sponge (foam) rubber for shoe insoles, or cushioning materials, one of the decisive requirements for the material is that it is capable of absorbing water vapor and additionally if possible, it is also permeable to water vapor, for example to create good wearing comfort on the body.

Since the above-mentioned fabrics are often used in areas in which a water-repellent effect is to be achieved and they can do so successfully at a relatively low price, the associated disadvantage of the non-absorption or non-permeability of water vapor (e.g. from Sweat). There has been no shortage of attempts to remedy this obvious deficiency, in particular attempts have been made to increase the porosity of the flat structures. By this measure, i.e. H. Usually the introduction of additional pores into the rubber sheet material, however, the structural strength of the materials produced therefrom is reduced and in some cases the water resistance of the materials, which is required per se, cannot be maintained. A certain water vapor permeability is observed in these foamed sheets, but no significant water vapor absorption can be determined.

From DT-PS 910 960 a process for the production of porous highly absorbent fabrics is known which provides products which, in addition to the cavities which usually form, also contain artificially produced fine and very fine pores and which should therefore be absorbent. The additional fine pores are created with water-soluble substances, which are incorporated into the fabrics during their manufacture in finely divided form and are removed from the manufactured structures, leaving behind fine pores. Water-soluble organic substances such as starch and protein are used as pore formers or protein-like substances, sugar, tragacanth, cellulose derivatives and synthetic resins, or substances that become water-soluble due to the action of ferments or enzymes. In the manufacture of the flat structures, the base material made of fleece is treated with an impregnating agent which contains the pore former; aqueous dispersions or emulsions of vulcanizable substances such as natural rubber, synthetic rubber or synthetic resin can be used as the impregnating agent.

DT-AS 12 04 186 describes a process for producing a chamois-like, absorbent, porous, coated fabric, in which a mixed fabric made of cotton and rayon fibers is roughened into the inner region of the fabric threads, then the mixed fabric is cleaned and desized, then the roughened fibers of the mixed fabric are coated on one or both sides with a paste of natural or synthetic rubber latex, a viscosity-increasing substance and an easily soluble salt suitable for pore formation, and finally the fabric is dried and the pore former is washed out. Vegetable gum, tragacanth, starch, dextrans and gum arabic are listed as viscosity-increasing substances, and sodium sulfate and chloride as pore formers.

The hydrophilized structure of a fiber and film-forming, water-insoluble polymer according to DT-OS 23 64 628 has particles of modified cellulose ether. The following are mentioned as polymers: regenerated Cellulose (cellulose hydrate), cellulose acetate, polyalkylene, alkyl cellulose, polyacrylonitrile, polyamide and polyester. The modified cellulose ethers are those whose mere degree of etherification would lead to water-soluble cellulose ethers and which are modified in such a way that at least for the most part they have become water-insoluble but have remained capable of absorbing water. The hydrophilized structure has the particles of modified cellulose ether evenly distributed in its polymeric mass or has a surface covered with the particles. The technical fields of application for films produced in this way are the use as ion exchangers or as dialysis or osmosis membranes.

The object of the invention is to propose a sheet-like structure based on rubber that is improved and permeable to water vapor compared to the prior art.

The invention is based on a water vapor-absorbent and permeable sheet made of natural or synthetic rubber or a rubber-like polymer with a uniformly incorporated addition of polymer particles. The fabric according to the invention is characterized in that it contains particles of at least one swellable, modified polymer as an additive. Swellable polymers are understood to mean those which swell in aqueous liquids, in particular with a water content of more than 50% by weight, or are caused by water molecules (eg water vapor) which come into contact with them in some other way. The term "evenly incorporated" means a statistical distribution. In particular, the polymer is at least about 50% by weight water-insoluble.

In a preferred embodiment, the fabric contains about 5 to 30% by weight, based on the rubber portion, of addition of the particles of at least one swellable, modified polymer. The particles advantageously have a size of ≦ 250 μm, in particular von 150 μm, and are generally in powdery or fibrous form.

• Vernetztes Polyalkylenoxid nach der DT-OS 20 48 721; beim Verfahren zur Herstellung dieses Produkts werden wasserlösliche Polyalkylenoxide mit einer genügend starken ionisierenden Strahlung behandelt, um eine Vernetzung und ein Unlöslichwerden des Polymeren zu erreichen. Die Bestrahlung kann dabei mit dem Polyalkylenoxid in festem Zustand oder in Lösung erfolgen.

The following are suitable, for example, as swellable, modified polymers for addition in the materials according to the invention:

• Cross-linked polyalkylene oxide according to DT-OS 20 48 721; in the process of making this product, water-soluble polyalkylene oxides are treated with sufficient ionizing radiation to achieve crosslinking and insolubility of the polymer. Irradiation can take place with the polyalkylene oxide in the solid state or in solution.

wobei n = 0, 1 oder 2 ist. Als α, ß-ungesättigte Säure sind dabei insbesondere Acrylsäure, Methacrylsäure, Itaconsäure, α-Phenylacrylsäure oder α-Benzylacrylsäure geeignet; bei der Herstellung des Mischpolymerisats werden zweckmäßig auf 85 % bis 99,9 % einer der ungesättigten Säuren 0,1 % bis 15 % des Acetals verwendet.The absorbent, crosslinked, carboxyl group-containing copolymer according to DT-OS 25 07 011 from an α, β-unsaturated acid and an acetal of the general formula

where n = 0, 1 or 2. Acrylic acid, methacrylic acid, itaconic acid, α-phenylacrylic acid or α-benzylacrylic acid are particularly suitable as α, β-unsaturated acid; in the preparation of the copolymer it is expedient to use 0.1% to 15% of the acetal to 85% to 99.9% of one of the unsaturated acids.

A hydrocolloid polymer according to US Pat. No. 3,670,731 (= _DT - _OS 16 42 072) which has been made water-insoluble by crosslinking and is suitable for absorbing and also holding back liquids; In particular, certain polyacrylamides, alkali metal salts of hydrolyzed polyacrylamides and alkali metal salts of polystyrene sulfonates are mentioned.

A water-swellable, crosslinked, insoluble, physiologically harmless polymer according to US Pat. No. 3,669,103 (= _DT - _OS 16 17 998) from the group of poly-N-vinylpyrrolidones, polyacrylamides, polyacrylic acid and polyglycols.

According to the process of DT-OS 25 41 035, at least for the most part water-insoluble, water-swellable absorbent polymers which are prepared in such a way that etherified in a homogeneous phase polyhydroxymethylene in an aqueous alkaline solution with an α-halocarboxylic acid and before, during or after etherification with a polyfunctional crosslinking agent compared to Pdlyhydroxymethylene in alkaline medium.

-glucose-Einheit) von 0,5 bis etwa 1 aufweist, dadurch reduziert, daß man dieses trockene Salz in feinverteilter Form einer Temperatur von etwa 130° bis etwa 210° C aussetzt, wobei hochquellbare Gelteilchen erhalten werden.In particular, the following swellable, modified carbohydrate derivatives can be used in the context of the invention: alkali metal salts of carboxymethyl cellulose which are heat-treated and swellable in water according to US Pat. No. 2,639,239; in the process for the manufacture of this product, the solubility of a water-soluble alkali metal salt of carboxymethyl cellulose, the one DS (= degree of substitution, ie number of substituted hydroxyl groups on an anhydro-

-glucose unit) from 0.5 to about 1, reduced by exposing this dry salt in finely divided form to a temperature of about 130 ° to about 210 ° C, whereby highly swellable gel particles are obtained.

• a) Cellulosematerialien mit carboxyalkylierenden Reaktionsteilnehmern behandelt und hierdurch wasserlösliche Carboxyalkylcellulose mit einem mittleren Substitutionsgrad von mehr als 0,35 Carboxyalkylresten pro Anhydroglucoseeinheit in der Cellulose, aber mit schlechten Eigenschaften in Bezug auf Aufsaugung und Zurückhaltung von Flüssigkeiten -bildet,
• b) einen solchen Teil der carboxyalkylierenden Reaktionsteilnehmer und während der Reaktion gebildeten Nebenprodukte entfernt, daß, bezogen auf das Gewicht der wasserlöslichen Carboxyalkylcellulose, wenigstens etwa 3 Gew.-% davon zurückbleiben, und
• c) die Carboxyalkylcellulose in Gegenwart der verbliebenen carboxyalkylierenden Reaktionsteilnehmer und Nebenprodukte der Reaktion einer Wärmebehandlung unterwirft und sie hierdurch wasserunlöslich macht und ihr ausgezeichnete Eigenschaften in Bezug auf Aufsaugung und Zurückhaltung von Flüssigkeiten verleiht.

Water-insoluble, liquid-absorbing and retaining, heat-treated carboxyalkyl celluloses according to US Pat. No. 3,723,413 (= DT-OS 2 314 689); in the process for the preparation of these products, the procedure is such that

• a) treating cellulose materials with carboxyalkylating reactants and thereby forming water-soluble carboxyalkyl cellulose with an average degree of substitution of more than 0.35 carboxyalkyl residues per anhydroglucose unit in the cellulose, but with poor properties with regard to absorption and retention of liquids,
• b) removing such a part of the carboxyalkylating reactants and by-products formed during the reaction that at least about 3% by weight thereof remain, based on the weight of the water-soluble carboxyalkyl cellulose, and
• c) the carboxyalkyl cellulose in the presence of the remaining carboxyalkylating reactants and by-products of the reaction of a heat treatment submits and thereby makes it water-insoluble and gives it excellent properties with regard to absorption and retention of liquids.

Absorbent carboxymethyl cellulose fibers which are suitable for use in fiber materials for the absorption and retention of aqueous solutions and are essentially water-insoluble according to US Pat. No. 3,589,364 (= DT-OS 1 912 740); such fibers consist of wet crosslinked fibers of water-soluble salts of carboxymethyl cellulose with a D.S. from about 0.4 to 1.6 and have the original fiber structure. About 3 to 10% by weight epichlorohydrin is preferably used as the crosslinking agent.

die Chlor-azomethingruppe

die Allyloxy-azomethingruppe

sind oder das Dichloressigsäure oder Phosphoroxychlorid ist.Chemically cross-linked, swellable cellulose ether according to .US-PS 3.936.441 (= DT-OS 2 357'079); these cross-linked cellulose ethers, in particular from carboxymethyl cellulose, carboxymethyl-hydroxyethyl cellulose, hydroxyethyl cellulose or methyl hydroxyethyl cellulose, are prepared in such a way that the ether, which is water-soluble per se, is reacted in an alkaline reaction medium with a crosslinking agent whose functional groups are the acrylamido group

the chloro-azomething group

the allyloxy azomething group

are or that is dichloroacetic acid or phosphorus oxychloride.

oder

wobei in Formel I: R₁ = die Hydroxyl-, eine Acylamino-oder eine veresterte Carbaminogruppe und R₂ = Wasserstoff oder die Carboxylgruppe bedeuten.Chemically modified, swellable cellulose ether according to US Pat. No. 3,965,091 (= DT-0S 2,358,150) .; these cellulose ethers, which have not been modified by crosslinking, are prepared in such a way that the ether, which is water-soluble per se, is reacted in an alkaline reaction medium with a mo.nofunctionally reacting compound which is described by one of the following two general formulas:

or

where in formula I: R ₁ = the hydroxyl, an acylamino or an esterified carbamino group and R ₂ = hydrogen or the carboxyl group.

Chemically cross-linked, swellable cellulose ether according to DT-OS 2 519 927; these crosslinked cellulose ethers are prepared in such a way that the per se water-soluble ether is reacted in an alkaline reaction medium with bisacrylamidoacetic acid as the crosslinking agent.

• a) mindestens ein wasserlösliches pulvriges polymeres Kohlenhydrat mit einer solchen Menge mindestens eines pulvrigen inerten Füllmittels, dessen Teilchen kleiner als die des Kohlenhydrates sind, so vermischt, daß ein wesentlicher Teil der Oberfläche des pulvrigen Kohlenhydrats bedeckt ist,
• b) unter Fortsetzen des Mischens das Gemisch unter gründlichem Rühren mit einem feinverteilten Wasserspray in einer solchen Menge in Berührung bringt, bei der das Gemisch in einer frei fließenden Teilchenform erhalten bleibt, und
• c) dann das erhaltene Gemisch bis zur Vernetzung des polymeren Kohlenhydrats einer ionisierenden Strahlung -aussetzt.

Free-flowing, radiation-crosslinked, water-swellable hydrophilic carbohydrates according to DT-AS 2 264 027; these products are manufactured in such a way that (with the following reaction stages can also be obtained with certain other polymers, such as polyethylene oxide or polyvinyl alcohol, similar products):

• a) at least one water-soluble powdery polymeric carbohydrate is mixed with such an amount of at least one powdery inert filler, the particles of which are smaller than those of the carbohydrate, such that a substantial part of the surface of the powdery carbohydrate is covered,
• (b) while mixing continues, bringing the mixture into contact with a finely divided water spray with thorough stirring in such an amount that the mixture is maintained in a free flowing particulate form; and
• c) then the mixture obtained is subjected to ionizing radiation until the polymeric carbohydrate is crosslinked.

die Acrylamidogruppe, wobei R₁= H oder CH₃ ist, oder

eine α-Nalogen-epoxygruppe, wobei Hal = tl oder Br ist oder

die Chlor-azomethingruppe oder

die Allyloxy-azomethingruppe oder das Phosphoroxychlorid ist. Eine andere Art der Herstellung verläuft derart, daß die Modifizierung mit einer unter den genannten Bedingungen gegenüber den Hydroxylgruppen der Stärke oder des Stärkeäthers monofunktionell reaktionsfähigen Verbindung durchgeführt wird, die durch eine der folgenden allgemeinen Formeln beschrieben wird:

oder

wobei R_{1 =} CH₃ oder H und R₂ = H und R₃ = CH₃, CH₂-OH, eine N-Methylen-acylamidogruppe mit 1 bis 3 C_-Atomen, eine veresterte N-Methylen-carbamido- oder N-Carboxymethylencarbamidogruppe mit 2 bis 7 C-Atomen ist, oder R₂ und R₃ = CH₃ oder CH₂-OH sind und'wobei R₄ und R₅ = H oder R₄ = H und R₅ = CH₃ oder R₄ und R₅ = CH₃ sind.Chemically cross-linked or otherwise modified, swellable starch ether according to DT note. P 26 34 539.1; these special starch ethers are made so that, for. B. as a modification, a crosslinking is carried out with a crosslinking agent which bears the following functional group which is reactive toward hydroxyl groups:

the acrylamido group, where R ₁ = H or CH ₃ , or

an α-halogeno-epoxy group, where Hal = tl or Br or

the chloro-azomething group or

is the allyloxy azomething group or the phosphorus oxychloride. Another type of preparation is such that the modification is carried out with a compound which is monofunctionally reactive under the conditions mentioned with respect to the hydroxyl groups of the starch or the starch ether, which is described by one of the following general formulas:

or

wherein R _{1 =} CH ₃ or H and R ₂ = H and R ₃ = CH _3, CH ₂ -OH group, an N-methylene-acylamido group having 1 to 3 C _- atoms, an esterified N-methylene-carbamido or N- Is carboxymethylene carbamido group having 2 to 7 carbon atoms, or R ₂ and R ₃ = CH ₃ or CH ₂ -OH and 'where R ₄ and R ₅ = H or R ₄ = H and R ₅ = CH ₃ or R ₄ and R ₅ = CH ₃ .

Alkali metal salts of carboxymethyl cellulose with increased absorption and retention capacity according to US Pat. No. 3,678,031 (= DT-OS 21 51 973). Although etherification agents containing carboxyl groups are used, which would result in a normally soluble cellulose ether, the conditions of the reaction are chosen such that alkali metal salts of carboxymethyl cellulose with a DS of 0.4-1.2, a water-soluble fraction of <35%, a water retention value (WRV) of about 1,000 to 7,000 and a salt water retention value of about 400 to about 2,500.

Water-insoluble carboxymethyl celluloses as used in DT-PS 10 79 796 and DT-AS 11 51 474, ie those with a DS of 0.05 to 0.3 and those in are essentially water-insoluble and also have a low DS.

Water-insoluble, more polymerized carboxymethyl or carboxyethyl cellulose with a substantial content of free carboxyl groups according to GB-PS 725 887 (= DT-PS 10.37 076) which are made water-insoluble by heating the water-soluble, acidic compounds to 80 ° C to 177 ° C.

Phosphorylated cellulose fibers according to DT-OS 24 47 282, as can be produced by reacting cellulose pulp with urea and phosphoric acid under the action of heat, followed by acidic hydrolysis and finally converting to the salt form.

Dry, solid, water-swellable, water-insoluble absorbents according to DT-OS 26 09 144, which consist of an ionic complex of a water-insoluble anionic polyelectrolyte and a cation of at least 3-valent metal; polyacrylic acid, starch or cellulose derivatives are suitable as polyelectrolytes.

Cellulose graft polymers according to DT-OS 25 16 380, which are produced by grafting the cellulose side chains from those polymer residues selected from the ionic and nonionic polymer residues. The following are suitable, for example: polyacrylic acid, sodium polyacrylate, polymethacrylic acid, potassium polymethacrylate, polyvinyl alcohol sulfate, polyphosphoric acid, Polyvinylamine, poly (4-vinylpyridine), hydrolyzed polyacrylonitrile, polymethyl methacrylate, polyvinyl acetate, polystyrene or polybutadiene.

Granulated, water-insoluble alkali metal carboxylate salts of starch-acrylonitrile graft copolymers according to US Pat. No. 3,661,815, which are prepared by saponification of starch-acrylonitrile graft copolymers with a base in an aqueous alkaline medium.

Modified cellulose material with improved retention capacity for both water and physiological liquids according to DT-OS 25 28 555, which by grafting an olefinically unsaturated, polymerizable monomer with hydrolyzable functional groups or a monomer carrying carboxyl groups onto a fibrous cellulose material and hydrolyzing or otherwise treating the grafted product is made with alkali. The product is first brought into the state of maximum swelling, then acidified to a pH at which it has the state of minimal swelling, then converted into the salt form under no swelling conditions and finally dried.

Modified polysaccharide according to DT-OS 26 47 420, made from polysaccharide, acrylamide, another vinyl monomer and a divinyl monomer under radical reaction conditions.

• Verwobene oder unverwobene Textilmaterialien aus einer oder mehreren Komponenten, z. B. aus Synthesefasern wie Polyamiden, Polyestern, Polyacrylnitril, PVC, Polyolefinen, Polyaminosäuren, sowie aus Glasfasern, regenerierten Fasern wie Viskosefasern, Acetatfasern und dgl., aus Naturfasern wie Baumwolle, Seide, Wolle, Leinen und Kollagen, erhalten durch Abreiben von Naturleder; oder blattartige Materialien, die aus einer oder mehreren Komponenten zusammengesetzt sind, z. B. aus synthetischen Harzen wie Polyamiden, Polyestern, Polyacrylnitril, PVC, Polyolefinen, Polyaminosäure, oder aus Naturleder, von dem die silbrige Oberfläche entfernt worden ist, oder aus Abfall-Leder erhaltenem Kollagen, Naturkautschuk und Synthesekautschuk.

The processes for the production of rubber sheets are known. The fabric can be a self-supporting film or. are produced by coating or impregnating a base made of natural or synthetic fiber material, non-woven textile materials or synthetic resin sheets; the rubber content can be either solid or foamed. The following documents are preferably used for coating or impregnation:

• Woven or unwoven textile materials made from one or more components, e.g. B. from synthetic fibers such as polyamides, polyesters, polyacrylonitrile, PVC, polyolefins, polyamino acids, and from glass fibers, regenerated fibers such as viscose fibers, acetate fibers and the like., From natural fibers such as cotton, silk, wool, linen and collagen, obtained by rubbing natural leather; or sheet-like materials composed of one or more components, e.g. B. from synthetic resins such as polyamides, polyesters, polyacrylonitrile, PVC, polyolefins, polyamino acid, or from natural leather, from which the silvery surface has been removed, or from waste leather obtained collagen, natural rubber and synthetic rubber.

The underlays can be coated or impregnated using various processes, and various processes for producing self-supporting films are also possible. The basic material for the production of the flat structures according to the invention is rubber. The following sub-terms are, for example, under the generic term rubber to understand: latex from wild or plantation rubber, pre-vulcanized latex, Positex (latex, the negative charge of which has been converted into a positive), rubber and regenerate dispersions, raw rubber types such as "smoked sheets" and "crepe", synthetic rubber types such as copolymers of Butadiene with styrene and butadiene with acrylonitrile, polymers and copolymers of chlorobutadiene, polymers and converted polymers from vinyl compounds, copolymers of isobutylene with isoprene, block polymers of butadiene, thioplastics, silicone rubber, regenerated rubber, factice and others.

• Die Verarbeitung von Latex erfolgt so, daß zunächst die Vulkanisationsagentien und sonstigen Hilfsprodukte wie Füllstoff, Alterungsschutzmittel, Weichmacher etc. in den Latex eingerührt werden, anschließend kann dann beispielsweise nach dem Tauchverfahren mit oder ohne Koagulationsmitteln, dem Schaumverfahren, durch elektrophoretische Abscheidung, dem Imprägnierverfahren oder dem Streichverfahren das gewünschte Flächengebilde erzeugt werden.

The processing of the rubber can generally be carried out as follows:

• The processing of latex is carried out in such a way that the vulcanization agents and other auxiliary products such as filler, anti-aging agent, plasticizer etc. are first stirred into the latex, then, for example, after the immersion process with or without coagulants, the foam process, by electrophoretic deposition, the impregnation process or the desired surface structure can be produced by the coating process.

Solid rubber is processed in such a way that the raw rubber bales are first shredded, the rubber is plasticized and the mixture to be processed is produced with conventional auxiliary products, and finally, for example, by calendering, friction and dipping or brushing rubber solutions to produce the desired sheet, finally the rubber sheet or the rubber-containing layer is vulcanized.

• 1 Eine Gummi-Textilbeschichtung wird erzeugt durch Auflösen von 30 Teilen der folgenden auf einer Walze erzeugten, vulkanisationsfähigen Mischung in 70 Teilen eines Benzin/Toluol-Gemisches aus 60 Teilen Benzin und 10 Teilen Toluol.
  
  Vor dem Verstreichen oder einem andersartigen Verarbeiten werden der Lösung die Teilchen aus mindestens einem modifizierten, quellfähigen Polymeren zugesetzt und darin gleichmäßig verteilt, anschließend wird das Gemisch verstrichen oder andersartig verformt und abschließend während etwa 30 min bei etwa 120° C vulkanisiert.
• 2 Ein Schaumgummi wird erzeugt aus
  
  Vor dem Schäumen und Vulkanisieren werden diesem Gemisch die Teilchen aus mindestens einem modifizierten, quellfähigen Polymeren zugesetzt und darin gleichmäßig verteilt.
• 3 Latexschaumteile können ausgehend von Naturlatex oder Syntheselatex wie folgt hergestellt werden, wobei die Teilchen aus mindestens einem quellfähigen, modifizierten Polymeren vor dem Aufschlagen, dem Koagulieren und der Vulkanisation des Latexes, in etwa ihrer 4-fachen Wassermenge aufgeschlämmt, der Latexmischung zugesetzt und darin gleichmäßig verteilt werden.
• 3.1 Die Naturlatexmischung setzt sich zusammen aus:
  
  Zum Koagulieren werden zu dem genannten Gemisch 20,0 Teile 10%iger wäßriger Ammoniumchlorid-Lösung gegeben.
• 3.2 Die Syntheselatexmischung setzt sich zusammen aus:
  
  Zum Koagulieren werden zu dem genannten Gemisch 2,0 - 4,0 Teile Silicofluorid gegeben.

When carrying out the examples, the procedure described in the following was used in particular (parts are parts by weight, percentages are given in% by weight):

• 1 A rubber textile coating is created by dissolving 30 parts of the following vulcanizable mixture produced on a roller in 70 parts of a gasoline / toluene mixture of 60 parts of gasoline and 10 parts of toluene.
  
  Before spreading or other processing, the particles of at least one modified, swellable polymer are added to the solution and uniformly distributed therein, then the mixture is spread or otherwise deformed and finally vulcanized at about 120 ° C. for about 30 minutes.
• 2 A foam rubber is made from
  
  Before foaming and vulcanization, the particles of at least one modified, swellable polymer are added to this mixture and uniformly distributed therein.
• 3 latex foam parts can be made from natural latex or synthetic latex as follows, the particles of at least one swellable, modified polymer, before slurrying, coagulating and vulcanizing the latex, slurried in about 4 times the amount of water, added to the latex mixture and evenly therein be distributed.
• 3.1 The natural latex mixture is composed of:
  
  For coagulation, 20.0 parts of 10% aqueous ammonium chloride solution are added to the mixture mentioned.
• 3.2 The synthetic latex mixture consists of:
  
  For coagulation, 2.0-4.0 parts of silicon fluoride are added to the mixture mentioned.

In order to produce the sheet-like structures according to the invention, the particles of at least one modified, swellable polymer, preferably in a proportion of 5 to 30% by weight, based on the finished film or the Layer or the rubber portion in the layer, added and evenly distributed therein; the mixture is then spread or otherwise deformed.

The fabrics according to the invention have a good ability to absorb and permeate water vapor, which goes far beyond a pure transport effect of the incorporated particles. In addition, the fabrics are also able to release the absorbed water vapor under certain conditions, such as staying in a different climate.

Since the properties of the fabric mentioned are not based solely on the significantly detectable effect due to the addition of the particles of at least one swellable, modified polymer, but also depend inter alia on the thickness of the film or coating, it is expedient to use a thickness of about 0 , 05 up to about 0.5 mm, in particular if, in addition to good water vapor absorption capacity, good water vapor permeability is also to be achieved.

The fabrics according to the invention with the properties mentioned are suitable, for example, as a self-supporting film or as a coating on a base, in particular as rubberized textile, shoe upper material, shoe insole, or carpet backing materials, i.e. for those areas of application in which body fluids, such as e.g. Sweat, occur. In foamed form, they can also be used as absorbents for hygiene articles 1, such as. B. tampons, because they can also absorb and retain water as foam.

• WRV Wasserrückhaltevermögen des quellfähigen, modifizierten Polymeren in Gew.-%, gemessen gegen 2000- fache Erdbeschleunigung, bezogen auf seinen wasserunlöslichen Anteil; das WRV wird nach Eintauchen der Probe in Wasser bestimmt,
• WUA wasserunlöslicher Anteil im quellfähigen modifizierten Polymeren,
• DS Substitutionsgrad, Anzahl der substituierten Hydroxylgruppen an den Anhydro-D-glucose-Einheiten, von 0,0 bis 3,0
• SV Saugvermögen des quellfähigen modifizierten Polymeren für 1%ige NaCl-Lösung in Gew.-%, bezogen.auf sein Gesamtgewicht; das SV wird bestimmt nach Aufsaugen von 1%iger wäßriger NaCl-Lösung durch die Probe bis zur Sättigung.
• WDA_DIN Die Wasserdampfaufnahme wird über den Gewichtsverlust einer unter den Bedingungen nach DIN 53 304 (Ausgabe vom Mai 1968) bei 102° C ± 2° C bis zur Gewichtskonstanz getrockneten Probe, bezogen auf das ursprüngliche Gewicht, ermittelt. Dabei wird zunächst die Probe im Anlieferungszustand sofort nach der Entnahme aus einem wasserdampfdichten Behälter auf 0,001 g genau gewogen. Die Probestücke werden dann im Wärmeschrank hängend bei 102° C ± 2° C während 15 h getrocknet und nach dem Abkühlen auf Raumtemperatur ebenfalls auf 0,001 g genau gewogen. Um die Wasserdampfaufnahmefähigkeit von Proben unter verschiedenen Bedingungen ausprüfen zu können, werden die jeweiligen Proben in verschiedene Klimata gehängt und nach bestimmten Zeiten werden diese entnommen und dann deren Wasserdampfaufnahme in Gew.-%, bezogen auf ihr Anfangsgewicht zu Beginn der jeweiligen Messung, ermittelt.
• WDD_PFI Wasserdampfdurchlässigkeit (nach W. Fischer und W. Schmidt, "Das Leder", E. Roether-Verlag Darmstadt, 27, 87 ff (1976)). Innerhalb der Apparatur herrscht eine Temperatur von 32° C, über der Probe ein Normklima - wenn nichts anderes angegeben ist - von 23° C / 50 % relative Feuchte, das von einem über dem Gerät angebrachten Ventilator durch einen leichten Luftstrom immer konstant gehalten wird. Die freie Prüffläche beträgt 10 cm². Auch innerhalb der Apparatur wird mit Hilfe eines Magnetrührers das Wasser von 32° C und die darüber befindliche. mit Wasserdampf gesättigte Atmosphäre ständing Bewegung gehalten. Die Bestimmung der WDD erfolgt durch die Bestimmung der Gewichtsabnahme des Prüfgefäßes mit der Probe. Die WDD wird in mg/cm² x h (x meist 1, aber auch 8 oder 24) angegeben.
• WDA_PFI Wasserdampfaufnahme (siehe auch WDD_PFI). Die Wasserdampfaufnahme wird gleichzeitig mit der WDD_PFI-Messung durchgeführt, die Bestimmung erfolgt durch Ermittlung der Gewichtszunahme der Probe; wenn nichts anderes angegeben ist, ist die Probe zum Außenklima hin durchlässig, d. h. sie wird nicht abgedeckt.

The parameters used in the description and examples for the characterization of the fabrics according to the invention and the swellable polymers present in them are to be understood as follows:

• WRV water retention capacity of the swellable, modified polymer in% by weight, measured against 2000 times gravitational acceleration, based on its water-insoluble fraction; the WRV is determined after immersing the sample in water,
• WUA water-insoluble fraction in the swellable modified polymer,
• DS degree of substitution, number of substituted hydroxyl groups on the anhydro-D-glucose units, from 0.0 to 3.0
• SV Suction rate of the swellable modified polymer for 1% NaCl solution in% by weight, based on its total weight; the SV is determined after absorbing 1% aqueous NaCl solution through the sample until saturation.
• WDA _DIN The water vapor absorption is determined from the weight loss of a sample dried under the conditions of DIN 53 304 (edition from May 1968) at 102 ° C ± 2 ° C to constant weight, based on the original weight. The sample is first weighed in the delivery state immediately after removal from a water vapor-tight container to an accuracy of 0.001 g. The specimens are then dried in a heating cabinet at 102 ° C ± 2 ° C for 15 h and, after cooling to room temperature, also weighed to the nearest 0.001 g. In order to be able to test the water vapor absorption capacity of samples under different conditions, the respective samples are hung in different climates and after certain times these are removed and then their water vapor absorption in% by weight, based on their initial weight at the start of the respective measurement, is determined.
• WDD _PFI water vapor permeability (after W. Fischer and W. Schmidt, "Das Leder", E. Roether-Verlag Darmstadt, 27, 87 ff (1976)). Within the The apparatus has a temperature of 32 ° C, above the sample there is a standard climate - unless otherwise stated - of 23 ° C / 50% relative humidity, which is always kept constant by a fan installed above the device by a slight air flow. The free test area is 10 cm ² . With the help of a magnetic stirrer, the water at 32 ° C and the water above is also inside the apparatus. atmosphere saturated with water vapor kept moving. The WDD is determined by determining the weight loss of the test vessel with the sample. The WDD is given in mg / cm ² xh (x mostly 1, but also 8 or 24).
• WDA _PFI water vapor absorption (see also WDD _PFI ). The water vapor absorption is carried out simultaneously with the WDD _PFI measurement, the determination is made by determining the weight gain of the sample; unless otherwise stated, the sample is permeable to the outside climate, ie it is not covered.

In all of the following examples, chemically cross-linked sodium carboxymethyl celluloses with the following parameters WUA ≧ 70%, WRV = 400 to 700%, SV = ₈ 00 to 1400%, DS = 0.8 were used as representative modified, swellable polymers with bisacrylamido-acetic acid to 1.1 and a particle size of ≦ 200 microns, with a proportion of 90 wt .-% of ≦ 100 microns used.

Examples 1 to 3 and Comparative Example V1 (Table I)

According to the invention, a rubber-coated textile fabric made of cotton with an addition in the layer of modified, swellable polymer in various amounts of 15% by weight (example 1), 20% by weight (example 2) and 25% by weight (example 3), based on the weight of the rubber layer, produced and compared with one without an additive (V1) with regard to water vapor permeability and water vapor absorption. These values increase with an increasing proportion of modified, swellable polymer; in the cases carried out there is no significant influence on the mechanical properties of the coated fabric. The fabrics coated with additives according to the invention have a clear water vapor permeability and water vapor absorption in comparison with the coated fabrics without additives.

Examples 4 to 6 and comparative examples V2 to V4 (Table II

• Beispiel V2 u. Beispiel 4: beide Außenflächen tragen eine Gummihaut
• Beispiel V3 u. Beispiel 5: eine Außenfläche zeigt einen offenen Schaum, eine Außenfläche trägt eine Gummihaut
• Beispiel V4 u. Beispiel 6: beide Außenflächen zeigen einen offenen Schaum

According to the invention, a foam rubber is produced from a rubber mass (in various thicknesses) with an addition of modified, swellable polymer in a proportion of 15% by weight, based on the weight of the foam rubber, and with a foam of the same thickness without any addition with regard to the increase in Comparison of water vapor absorption after increasing exposure to water vapor. The foam rubbers have the following structure:

• Example V2 u. Example 4: Both outer surfaces have a rubber skin
• Example V3 u. Example 5: an outer surface shows an open foam, an outer surface has a rubber skin
• Example V4 u. Example 6: Both outer surfaces show an open foam

A foam rubber with additive produced according to the invention absorbs more water vapor than a similar foam rubber without additive.

Example 7 and Comparative Example V5 (Table III)

According to the invention, a foam is made from natural latex with an addition of 15% by weight of modified, swellable polymer, based on the weight of the finished latex foam (Example 7) and with such an addition (V5) with regard to water vapor absorption in various climates and compared with increasing exposure to water vapor. A latex foam with additive produced according to the invention absorbs significantly more water vapor than a similar foam without additive.

Examples 8 to 10 and Comparative Example V 6 (Table IV)

According to the invention, a foam made of synthetic latex is used an additive in various amounts of 10 wt .-% (Example 8), 20 wt .-% (Example 9) and 30 wt .-% (Example 10), based on the weight of the finished latex foam, produced with and without such Addition (V6) compared with regard to water vapor absorption. The foams are exposed to a humidity of 65% relative humidity (RH) at 20 ° C. and then to different humidities, and the respective moisture increase or decrease is measured after a certain period of time. With an increasing amount of additive, the water vapor absorption capacity of the foam increases, a foam with additive absorbs significantly more water vapor than a similar foam without additive.

Claims (8)

1. Water vapor-absorbent and permeable sheet made of natural or synthetic rubber or a rubber-like polymer with a uniformly incorporated addition of polymer particles, characterized in that it contains particles of at least one swellable, modified polymer as an additive. - 2. Flat structure according to claim 1, characterized in that the swellable, modified polymer is at least about 50 wt .-% water-insoluble. 3. Flat structure according to claim 1 or 2, characterized in that it contains particles of at least one swellable, modified carbohydrate derivative as an additive. 4. Flat structure according to one of claims 1 to 3, characterized in that it contains as an additive particles from at least one swellable, modified starch or cellulose ether. 5. Flat structure according to one of claims 1 to 4, characterized in that the starch or cellulose ether has been modified by a crosslinking effected with the aid of thermal energy, radiation or by an additional chemical compound. 6. Flat structure according to one of claims 1 to 5, characterized in that it contains about 5 to 30 wt .-% of additive, based on the rubber content. 7. A process for the production of a water vapor-absorbent and permeable sheet material according to claim 1, characterized in that the particles of at least one swellable, modified polymer are added to a rubber-containing base material and are evenly distributed therein, and the mixture is then passed, optionally with foaming, or is otherwise deformed and solidified. 8. The method according to claim 7, characterized in that the particles are added in a proportion of 5 to 30 wt .-%, based on the rubber content of the finished fabric.