EP4259869A1

EP4259869A1 - Textile sheet material

Info

Publication number: EP4259869A1
Application number: EP20823765.1A
Authority: EP
Inventors: Thomas Lehotkay; Johanna HRGOVIC
Original assignee: Wacker Chemie AG
Current assignee: Wacker Chemie AG
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2023-10-18
Also published as: US20240026583A1; WO2022122120A1

Abstract

The invention inter alia relates to methods for producing textile sheet materials by applying one or more binder compositions to fibers, characterized in that binder compositions contain one or more polysaccharides and one or more polymers of vinyl esters.

Description

Textile fabrics

The invention relates to processes for the production of textile fabrics, the textile fabrics obtainable in this way, and binder compositions for the production of textile fabrics.

Textile fabrics are based on fiber material that can be woven (wovens), knitted (knitwear) or laid (nonwovens) and is reinforced with binders, such as nonwovens or felt. Nonwovens are usually produced by airlay, wetlay or spunlay processes. Polymers of ethylenically unsaturated monomers are often used as binders to strengthen the textile fabrics and are applied to the fiber material, for example in the form of aqueous dispersions, followed by subsequent drying.

For ecological reasons, there is now a desire to at least partially replace petrochemical polymers with natural, renewable raw materials. Losses in performance properties should be avoided as far as possible. A problem arises from the fact that renewable raw materials have a completely different chemical structure than petrochemical polymers, so that when petrochemical polymers are substituted in established formulations or processes by natural, renewable biopolymers, incompatibilities often arise and different substances separate, and there are therefore no stable mixtures, which is reflected in the unacceptable properties of the application products. This is exacerbated by the fact that biopolymers are less of a single type, but are also present as mixtures of different substances or can have broad molecular weight distributions, which in turn can vary depending on the origin of the biopolymers. In addition, textile fabrics with biopolymers as binders often do not have the required mechanical strength or resilience, for example insufficient wet tensile strength or solvent resistance, particularly in the case of short fibers.

Against this background, the task was to produce textile fabrics using binder compositions that contain natural, renewable raw materials and lead to textile fabrics whose application-related property profile comes close to that of textile fabrics conventionally produced exclusively with petrochemical polymers as binders. The binder compositions should be able to be applied by established methods and be compatible with otherwise conventional formulation components and result in stable mixtures that do not tend to separate. In addition, textile fabrics should also be provided that are biodegradable to the greatest possible extent. The textile fabrics should preferably also have advantageous mechanical strengths.

Biopolymers are used, for example, in technologies that are far removed from textile fabrics. Thus, WO 9222606A1 describes hot-melt adhesives made from meltable polysaccharides and ethylene-vinyl acetate copolymers and WO9742271A1 describes adhesives made from synthetic polymers in combination with dextrin (derivatives). WO2008003043A2 teaches matrices made from degradable and non-degradable polymers for the incorporation of therapeutically active compounds. WO2010/133560 or also WO2004/085533 disclose thermoplastically processable mixtures based on synthetic polymers and flour or starch for the extrusion of shaped bodies. WO2019 / 043134 are generally plastic products based on polyesters, such as Lactic acid or terephthalic acid, and for example polysaccharides can be removed.

One subject of the invention is a method for producing textile fabrics by applying one or more binder compositions to fibers, characterized in that binder compositions contain one or more polysaccharides and one or more polymers of vinyl esters.

Another object of the invention are textile fabrics obtainable by the process of the invention.

Another subject of the invention are binder compositions for textile fabrics containing one or more polysaccharides and one or more polymers on one or more vinyl esters and one or more ethylenically unsaturated monomers, the carboxyl, anhydride, silane, isocyanate -, amide, hydroxyl, epoxy or NH groups (crosslinking monomers), based. With such binder compositions it is possible in particular to further improve the mechanical strength, such as wet tensile strength, of the textile fabric.

The polymers of vinyl esters (vinyl ester polymers) are preferably based on vinyl esters of unbranched or branched alkyl carboxylic acids having 1 to 18 carbon atoms, such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methyl vinyl acetate, vinyl pivalate and vinyl esters of «-branched Monocarboxylic acids with 5 to 15 carbon atoms, for example Veo-Va9 ^R or VeoValO ^R (trade name from Shell). Vinyl acetate is preferred.

Preferred vinyl ester polymers are based at 50 to 100% by weight, more preferably 60 to 94% by weight and most preferably 70 to 90% by weight of vinyl esters based on the total weight of the vinyl ester polymers.

If appropriate, the vinyl ester polymers are also based on one or more monomers selected from the group comprising acrylic esters or methacrylic esters of branched or unbranched alcohols having 1 to 15 carbon atoms, dienes, olefins, vinyl aromatics and vinyl halides. Olefins are preferred here.

The vinyl ester polymers are preferably based on from 1 to 45% by weight, more preferably from 5 to 30% by weight and most preferably from 15 to 25% by weight of such additional monomers, based on the total weight of the vinyl ester polymers.

Suitable monomers from the group of esters of acrylic acid or methacrylic acid are esters of unbranched or branched alcohols having 1 to 15 carbon atoms. Preferred methacrylic esters or acrylic esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, norbornyl acrylate. Methyl acrylate, methyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate and norbornyl acrylate are particularly preferred.

Examples of suitable dienes are 1,3-butadiene and isoprene. Examples of copolymerizable olefins are ethene and propene. Styrene and vinyl toluene, for example, can be copolymerized as vinyl aromatics. Vinyl chloride is preferred as the vinyl halide.

The vinyl ester polymers are preferably also based on one or more ethylenically unsaturated monomers which also carry carboxyl, anhydride, silane, isocyanate, amide, hydroxyl, epoxy or NH groups (crosslinking monomers). Crosslinking monomers bearing NH groups are preferred here. Vinyl ester polymers containing crosslinking monomer units lead to textile fabrics with higher strengths, such as dry strength, and in particular wet strength and solvent strength.

Examples of carboxy-functional comonomers are ethylenically unsaturated mono- and dicarboxylic acids having 2 to 10 carbon atoms, preferably acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid and maleic acid. Examples of anhydride-functional comonomers are maleic anhydride or ethylenically unsaturated succinic anhydride derivatives, such as alkenyl succinic anhydrides, in particular having 2 to 25 carbon atoms in the alkenyl radical. Examples of silicon-functional comonomers are acryloxypropyltri(alkoxy)- and methacryloxypropyltri(alkoxy)-silanes, vinyltrialkoxysilanes and vinylmethyldialkoxysilanes, it being possible for ethoxy groups, for example, to contain ethoxy and ethoxypropylene glycol ether radicals. Examples of hydroxy-functional comonomers are hydroxyalkyl acrylates and hydroxyalkyl methacrylates with a C 1 -C 8 alkyl radical, preferably hydroxyethyl acrylate and methacrylate, hydroxypropyl acrylate and methacrylate, hydroxybutyl acrylate and hydroxybutyl methacrylate. Examples of epoxy functional comonomers are glycidyl acrylate and glycidyl methacrylate. Examples of NH-functional comonomers are acrylamide, methacrylamide, N-alkylol-functional comonomers with C to C4-alkylol residue, preferably N-methylol residue, such as N-methylolacrylamide (NMA), N-methylolmethacrylamide, N -Methylolallylcarbamate, C i- to C4-alkyl ethers of N-methylolacrylamide, N-methylolmethacrylamide and N-methylolallylcarbamate, for example their isobutoxyethers, and C i- to C4-alkyl esters of N-methylolacrylamide and N-methylolmethacrylamide and the N-methylolallyl carbamate.

Particularly preferred crosslinking monomers are N-methylol functional monomers, most preferred are N-methylolacrylic amide, N-methylolmethacrylamide, N-methylolallylcarbamate, C- to C4-alkyl ethers of N-methylolacrylamide, such as the isobutoxyether.

The vinyl ester polymers are preferably based on 0 to 10 wt. -%, particularly preferably 0.1 to 5 wt. -% and most preferably 0.5 to 2 wt. -% on crosslinking monomers, based on the total weight of the vinyl ester polymers.

Preference is given to the vinyl ester polymers mentioned below, in which the abovementioned crosslinking monomers can optionally also be polymerized, preferably in the abovementioned amounts: vinyl acetate polymers; vinyl ester-ethylene copolymers, such as vinyl acetate-ethylene copolymers; Vinyl acetate copolymers with one or more copolymerizable vinyl esters such as vinyl laurate, vinyl pivalate, vinyl 2-ethylhexanoic acid ester, vinyl ester of an alpha-branched carboxylic acid having 5 to 15 carbon atoms, in particular versatic acid vinyl ester (Veo-Va9R, VeoVal OR) which may also contain ethylene; Vinyl ester-ethylene-vinyl chloride copolymers, vinyl acetate and/or vinyl propionate and/or one or more copolymerizable vinyl esters such as vinyl laurate, vinyl pivalate, vinyl-2-ethylhexanoic acid ester, vinyl ester of an alpha-branched carboxylic acid having 5 to 15 C- Atoms, in particular Versatic acid vinyl ester (VeoVa9R, VeoVal OR), are included; Vinyl ester-acrylic acid ester copolymers, in particular with vinyl acetate and butyl acrylate and/or 2-ethylhexyl acrylate, which may also contain ethylene; Vinyl ester-acrylic acid ester copolymers with vinyl acetate and/or vinyl laurate and/or versatic acid vinyl ester and acrylic acid ester, in particular butyl acrylate or 2-ethylhexyl acrylate, which may also contain ethylene.

Vinyl acetate polymers, vinyl acetate-ethylene copolymers, vinyl acetate-ethylene-vinyl chloride copolymers, vinyl ester-acrylic acid ester copolymers are particularly preferred. in particular with vinyl acetate and butyl acrylate and/or 2-ethylhexyl acrylate, in which optionally N-methylol-functional monomers can also be polymerized, preferably in the amounts mentioned above.

Most preferred are N-methylol functional vinyl ester polymers such as vinyl acetate-N-methylolacrylamide copolymers and vinyl acetate-ethylene-N-methylolacrylamide copolymers and combinations thereof.

The selection of the monomers or the selection of the proportions by weight of the comonomers is carried out in such a way that the polymers have a glass transition temperature Tg of -50.degree. C. to +120.degree. C., preferably -35.degree. C. to +45.degree. The glass transition temperature Tg of the polymers can be determined in a known manner by means of differential scanning calorimetry (DSC). The Tg can also be approximately predicted using the Fox equation. According to Fox T.G., Bull. Am. Physics Soc. 1, 3, page 123 (1956), 1/Tg = xl/Tg1 + x2/Tg2 + ... + xn/Tgn, where xn is the mass fraction (wt%/100) of monomer n, and Tgn is the glass transition temperature in Kelvin of the homopolymer of monomer n. Tg values for homopolymers are listed in Polymer Handbook 2nd Edition, J. Wiley & Sons, New York (1975).

The binder compositions preferably contain from 1 to 90% by weight, more preferably from 10 to 85% by weight, even more preferably from 15 to 80% by weight, particularly preferably from 20 to 75% by weight and most preferably from 30 to 70% by weight vinyl ester polymers based on the dry weight of the binder compositions.

Preference is given to protective colloid-stabilized vinyl ester polymers, particularly preferably to emulsifier-stabilized vinyl ester polymers and most preferably to vinyl ester polymers stabilized with nonionic emulsifiers, or combinations thereof. The vinyl ester polymers are preferably not protective colloid-stabilized ted. The object according to the invention can be achieved even better with these measures.

Examples of protective colloids are polyvinyl alcohols, polyvinyl acetals, polyvinylpyrrolidones, copolymers of (meth)acrylates with carboxyl-functional comonomer units, poly(meth)acrylamide, polyvinylsulfonic acids and their copolymers, melamine formaldehyde sulfonates, naphthalene formaldehyde sulfonates, styrene maleic acid and vinyl ether maleic acid copolymers. Preferred protective colloids are partially hydrolyzed polyvinyl alcohols, preferably with a degree of hydrolysis of 80 to 95 mol%, in particular 85 to 92 mol% and preferably a Höppler viscosity in 4% aqueous solution of 1 to 30 mPas, in particular 3 to 15 mPas (method according to Höppler at 20°C, DIN 53015) . The protective colloids mentioned can be obtained by methods known to those skilled in the art.

The vinyl ester polymers are generally not stabilized with polysaccharides. The polysaccharides contained in the binder compositions generally do not function as protective colloids. The polysaccharides and the vinyl ester polymers, in particular the protective colloid and/or emulsifier stabilized vinyl ester polymers, are preferably present side by side.

The proportion of protective colloid is preferably 0 to 30% by weight, particularly preferably 0.5 to 25% by weight and most preferably 1 to 20% by weight, based on the total weight of the vinyl ester polymers.

Anionic, cationic or nonionic emulsifiers or combinations thereof can be used. Anionic emulsifiers are preferred, and nonionic emulsifiers are particularly preferred. Examples of anionic emulsifiers are alkyl sulfates, sulfonates or carboxylates with a chain length of 8 to 18 carbon atoms, alkyl or alkylaryl ether sulfates, sulfonates or carboxylates with 8 to 18 carbon atoms in the hydrophobic radical and up to 40 ethylene or Propylene oxide units, alkyl or alkylaryl sulfonates having 8 to 18 carbon atoms, esters and half esters of sulfosuccinic acid with monohydric alcohols or alkylphenols, or phosphates, ether phosphates, phosphonates and ether phosphonates and combinations thereof.

Examples of nonionic emulsifiers are alkyl polyglycol ethers or alkylaryl polyglycol ethers with 8 to 40 ethylene oxide units or ethylene oxide/propylene oxide block copolymers with 2 to 40 EO or PO units or generally EO-PO copolymers, and also alkyl polyglycosides with 1 to 20 C Atoms and ether alkyl polyglycosides with 2 to 40 EO or PO units or their.

The proportion of emulsifier is preferably 0 to 15% by weight, particularly preferably 0.1 to 5% by weight and most preferably 0.5 to 3% by weight, based on the total weight of the vinyl ester polymers.

The vinyl ester polymers can be prepared by means of known free-radically initiated polymerization processes, for example by means of aqueous suspension polymerization or preferably aqueous emulsion polymerization, as described, for example, in WO2015/067621.

The vinyl ester polymers are preferably present in the form of aqueous dispersions with a solids content of preferably 10 to 70% by weight, particularly preferably 40 to 60% by weight. The Brookfield viscosity of the aqueous dispersions of the vinyl ester polymers is preferably 50 to 10,000 mPas, particularly preferably 100 to 2000 mPas (determined using a Brookfield viscometer at 23° C. and 20 rpm with a solids content of the dispersions of 49 to 51% by weight). %) .

Alternatively, the vinyl ester polymers can also be in the form of water-redispersible powders (polymer powder). Such polymer powders can be obtained, for example, by spray drying aqueous polymer dispersions. Additives such as flame retardants, plasticizers, fillers and complexing agents can optionally be added during drying. Dispersing such polymer powders again leads to vinyl ester polymers in the form of aqueous dispersions.

The polysaccharides can be, for example, starch, glycogen, cellulose, cellulose derivatives such as chitosan and chitin, hyaluronic acid, glycosaminoglycans, alginates, galactans, cane sugar, maltodextrin or the products obtained by enzymatic or chemical cleavage or chemical modification of the aforementioned polysaccharides, or polysaccharides based on the monomers glucose, sucrose, fructose, galactose, lactose, maltose, mannose or the respective tautomeric structures or combinations thereof. Furthermore, the polysaccharides can also be modifications with polymers based on protein structure or amino acids, such as glycoproteins or their derivatives. Cellulose, cellulose derivatives, starch and their short-chain degradation products, such as dextrins and maltodextrins, are preferred. Esterifications or etherifications may be mentioned as chemical modifications, such as carboxymethylation, oxidation reactions or also nonionic, anionic or cationic modifications. Examples of these are carboxymethyl, methyl, hydroxyethyl or hydroxypropyl cellulose or starch, starch ethers or starch phosphate esters or their oxidation products. Typical sources of polysaccharides are grain, tubers, roots, legumes, fruit starch, hybrid starch, corn, pea, potato, yam, wheat, barley, rice, sorghum or tapioca. Cold water soluble polysaccharides are preferred. The polysaccharides have molecular weights of preferably 300 to 2,700,000 g/mol. The polysaccharides are preferably based on 2 to 15,000 glucose molecules. The object according to the invention can be achieved even better with the preferred polysaccharides.

The binder compositions preferably contain from 5 to 95% by weight, more preferably from 15 to 90% by weight, even more preferably from 20 to 80% by weight, particularly preferably from 25 to 70% by weight and most preferably from 30 to 60% by weight polysaccharides based on the dry weight of the binder compositions.

The binder compositions preferably contain one or more crosslinkers, such as chemical crosslinkers, electrostatic crosslinkers or van der Waals crosslinkers and combinations thereof.

Examples of chemical crosslinkers are alkyl ureas, such as methyl ureas and derivatives thereof, in particular dimethyl ethylene urea and derivatives thereof, for example ARKOFIX® NZF (trade name from Archroma); Melamine crosslinking agents and derivatives thereof, such as MADURIT® MW 125 (trade name from INEOS) or KNITTEX® CHN (trade name from Huntsman); aliphatic polycarboxylic acids such as butane-1,2,3,4-tetracarboxylic acid, polyisocyanates; Citric acid, protected polyisocyanates, epoxides, halogenated hydrocarbons such as bromine or chlorine hydrocarbons, in particular chloroform or trichloromethane, or alkoxylated silanes or combinations thereof.

Electrostatic crosslinkers generally contain ionic groups or groups that form hydrogen bonds, such as CN-, C- 0, HN, HO, HS groups or ionic substances with cationic or anionic functional groups.

Examples of electrostatic crosslinkers with groups that form hydrogen bonds are polyacrylamides (PAM) and their derivatives. Substances with cationic functional groups are, for example, quaternary ammonium compounds or protonatable amine compounds, such as monoammonium or polyammonium compounds, for example polyamidoamine-epichlorohydrin resins (PAE, trade name KYMENE® from Solenis); or partially or fully protonated chitosans or their reaction products, for example with epichlorohydrins, and combinations thereof. Substances with anionic functional groups are, for example, mono- or poly-carboxylates, such as carboxymethyl cellulose (CMC), sulfonates, sulfinates or sulfides, and also copolymers of polyacrylamides with carboxy groups or combinations thereof.

Van der Waals crosslinkers are, for example, high-molecular nanocomposites such as nanocellulose or synthetic nanoplastics.

The binder compositions contain preferably 0 to 40% by weight, more preferably 0.1 to 35% by weight, particularly preferably 1 to 25% by weight and most preferably 2 to 15% by weight of crosslinking agent, based on the dry weight of the binder compositions.

Furthermore, the binder compositions may contain one or more additives, such as emulsifiers, protective colloids such as polyvinyl alcohols, polyurethanes, polyacrylates and derivatives thereof, catalysts, wetting agents or dispersing agents, dyes, matting agents, fillers such as inorganic salts (e.g. CaCOa, NaCl, TiCh, kaolin , silicic acids and their derivatives and combinations thereof), optical brighteners Based on, for example, stilbene compounds, free-radical scavengers or color stabilizers, antioxidants such as butylated hydroxytoluene, hydroxybenzophenone, salicylic acid esters, complexing agents such as water softeners based on ethylene tetraacetate salts, also superabsorbent polymers, grip-enabling components such as plasticizers, hydrophobing agents such as fluorocarbons, silicones, natural and synthetic waxes (e.g. paraffins, and polyethylenes), resins, flame retardant additives, antistatic additives, biocides, rheology additives, foam regulators or retention additives.

Preferred additives are emulsifiers and, in particular, catalysts.

The binder compositions preferably contain from 0 to 40% by weight, more preferably from 0.1 to 30% by weight and most preferably from 1 to 20% by weight of additives, based on the dry weight of the binder compositions.

Examples of emulsifiers are fatty alcohol ethoxylates with low degrees of ethoxylation, in particular 2 to 5 ethoxy units, di-isotridecyl sulfosuccinate or their salts, in particular sodium salts, or combinations thereof. The binder compositions preferably contain from 0 to 15% by weight, more preferably from 0.1 to 5% by weight and most preferably from 0.5 to 3% by weight of emulsifiers, based on the dry weight of the binder compositions. For example, secondary properties such as hydrophilicity, soiling behavior, wettability or yellowing of the textile fabric can be influenced with emulsifiers.

Preference is given to acidic catalysts such as ammonium chloride, carboxylic acids such as citric acid, acetic acid, malic acid, formic acid, tartaric acid, oxalic acid, in particular hydroxy or dicarboxylic acids, sulfuric acid, phosphoric acid or, in general, stedt acids . In the case of Bronsted acids, a pH of preferably 0 to 5 and particularly preferably 2 to 4 is set. Acid catalysts are preferably added in amounts of 0 to 3% by weight, preferably 0.1 to 2% by weight, based on the dry weight of the binder compositions.

The fibers are generally based on natural or synthetic, especially organic, materials. Examples of synthetic fibers are viscose, polyester, polyamide, polypropylene or polyethylene fibers or their mixtures or their co-extrudates, which are also referred to, for example, as "BiCo_Fibers". Examples of natural fibers are wood pulp - (Pulp), leather, fur, wool, cotton, jute, flax, hemp, coconut, ramie, sisal and cellulose fibers Cellulosic fibers such as viscose, modal, lyocell and acetate are preferred , triacetate, cupro, rayon and cellulose fibers from cellulose. Fiber mixtures, which preferably contain several of the aforementioned fibers, are particularly preferred. The fibers are preferably not based on inorganic materials. The fibers are therefore preferably no ceramic fibers or mineral fibers and in particular no glass fibers. Such Fibers can be made conventionally and are commercially available.

The fibers can be of any length, such as lengths from 1 mm to infinite length, preferably 5 mm to 100 mm, more preferably 7 mm to 75 mm and most preferably 10 mm to 60 mm. The fibers have diameters of preferably 0.1 μm to 1 mm, particularly preferably 0.5 μm to 100 μm and most preferably 1 μm to 50 μm.

The fibers can be loose or in the form of bundles or woven textiles, yarns or preferably in the form of nonwovens such as fleece, felt, scrims or knitted fabrics, or woven fabrics. be used on floors or carpets. The nonwovens can optionally be thermally or mechanically preconsolidated, for example needled or hydroentangled.

Binder compositions can, for example, be in solid form, preferably in liquid form, in particular in aqueous form. Binder compositions in solid form can be converted into aqueous form by adding water.

The binder compositions in aqueous form have a solids content of preferably 1 to 80% by weight, particularly preferably 10 to 70% by weight and most preferably 20 to 60% by weight.

To produce the binder compositions, the vinyl ester polymers, polysaccharides, any crosslinking agents and any additives are mixed with one another. For example, polysaccharides in solid or aqueous form can be mixed with vinyl ester polymers in the form of water-redispersible powders, and water can optionally be added at the same time or at a later point in time. The polysaccharides are preferably introduced in aqueous form and the vinyl ester polymers in the form of aqueous dispersions. The polysaccharides are preferably stirred into water under high shear. Hot-water-soluble polysaccharides are preferably stirred into hot water or diluted with hot water after pre-melting. Cold-water-soluble polysaccharides are preferably stirred into water at room temperature, for example 20 to 30° C., with stirring, for example with a paddle stirrer, preferably until optical homogeneity. Vinyl ester polymers are then preferably added in the form of aqueous dispersions. To produce the textile fabrics, for example, the fibers can be mixed with the binder compositions and the resulting mixture laid out by conventional methods of nonwoven technology, for example using air-laying, wet-laying, direct spinning or carding devices, and then optionally solidified will.

Alternatively, the fibers can also be spread out flat and, if appropriate before or after solidification, the binder compositions can be applied. Such approaches are also common. The fibers can be laid out, for example, by means of an air-laying, wet-laying, direct spinning or carding device. Optionally, prior to application of the binder composition, it can also be mechanically consolidated, for example by cross-laying, needling or hydro-entanglement. The binder compositions can be applied, for example, in the form of a sheet, in spots or in a pattern over the entire area or partial areas of the fibers. The application can take place, for example, by compulsory application, such as spraying, padding (padding, padding), coating, brushing, dipping or by means of foam application, or by non-compulsory applications, such as the exhaust method, or by combined methods, for example the overflow jet method.

The product thus obtained can then be treated for drying, solidifying, fixing or binding, for example by applying elevated temperatures and/or pressure, for example at 120 to 220° C., preferably for 20 seconds to 5 minutes. Air, circulating air, air flow or infrared drying (LR drying) can also be used.

The binder compositions are also suitable for producing laminates, in which case two fiber layers are bonded together, or a fiber layer is bonded to another substrate. will stick. The procedure can be such that a fiber layer is laid out, with the binder composition being mixed beforehand or applied after laying out, and a further fiber layer being laid on, for example by air laying. Instead of the second fiber layer, another substrate, for example a plastic film, can also be placed on top. Bonding then takes place through the application of temperature and, if necessary, pressure. With this procedure, for example, insulating materials, for example made of recycled cotton, are accessible, which are permanently laminated, for example, with a fiber fleece as a cover fleece.

To produce the textile fabrics, the aqueous binder composition is used in an amount of preferably 1 to 50% by weight, more preferably 5 to 30% by weight and most preferably 10 to 25% by weight, based in each case on the total weight of the Fibers (dry/dry) . Vinyl ester polymers are used in an amount of preferably 1 to 50% by weight, more preferably 5 to 30% by weight and most preferably 10 to 25% by weight, based on the total weight of the fibers (dry/dry). The proportion of fibers is preferably 40 to 99% by weight, particularly preferably 50 to 90% by weight and most preferably 60 to 80% by weight, based in each case on the total weight of the textile fabric.

The textile fabrics produced according to the invention are preferably nonwovens, in particular tissues, felts, waddings or coarse-meshed, loose wovens, knitted fabrics or warp-knitted fabrics. The textile fabrics can be used, for example, in the automotive sector, for household products such as tablecloths, hygiene items such as toilet paper, in the clothing industry, for medical textiles or geotextiles. The binder compositions are also suitable for the production of voluminous nonwovens or wadding, which are used, for example, as semi-finished products for the production of molded parts from fiber materials or as padding, insulation and filter wadding. For this purpose, the binder compositions can be applied to the fibers and solidified by increasing the temperature, preferably in a mold.

The binder compositions according to the invention, which contain vinyl ester polymers in addition to polysaccharides, are surprisingly stable and do not tend to separate, not even in the plants and process conditions in the production of textile fabrics. The binder compositions can be applied as binders for textile fabrics by established methods.

In addition, the textile fabrics produced according to the invention have the desired performance properties, such as mechanical properties, and permanently fix the fibers, which represents a particular challenge when using binders containing biopolymer components. With the present invention, textile fabrics with advantageous strength, such as dry strength or even wet strength, or improved solvent resistance, are accessible using polysaccharides in binders, which have the desired resistance to mechanical stress without compromising the integrity and elasticity of the s textile fabric significantly to influence sen.

In addition to the goal of providing more textile fabrics based on renewable raw materials, the biodegradability of textile fabrics is also an important ecological criterion. This criterion can also be advantageously achieved with the textile fabrics produced according to the invention. The following examples serve to further explain the invention:

Preparation of the binder compositions:

The polysaccharides (hereinafter abbreviated as "PSC") were stirred into water under high shear.

Here, hot-water-soluble polysaccharides were stirred in with hot water under high shear or diluted with hot water by pre-melting.

Cold-water-soluble polysaccharides were mixed with water at room temperature with a paddle stirrer at 400-1000 rpm for 15-30 minutes until optically homogeneous.

Vinyl ester polymers (abbreviated to “VAE”) were then added in the form of an aqueous dispersion, and stirring was continued for 5 minutes using a paddle stirrer.

Table la: binder compositions of Examples 1 to 3: a) : VAc : vinyl acetate; E: ethylene; NMA: N-methylolacrylamide;

PVOH:

polyvinyl alcohol; b) : anionic emulsifier; c) : non-ionic emulsifier; d) the details in wt. % are based on the total weight of the aqueous vinyl ester polymer dispersion; the amount remaining to 100% by weight is the water content; e) PSC 1: maltodextrin (obtained from Avebe);

PSC 2: dextrin with 6000 to 7000 glucose units (obtained from Avebe). Testing of the compatibility and storage stability of the binder compositions:

The binder compositions were based on 50 wt. -% (dry) on the polysaccharides (PSC) and aqueous emulsifier or polyvinyl alcohol-stabilized vinyl ester polymer dispersions (VAE) given in Table la and were stored for one month after their preparation at room temperature and according to the table 1b given periods of time on their storage stability or. Separation checked. The results are summarized in Table 1b.

Table 1b: Storage stability of the binder compositions of Examples 1 to 3:

Surprisingly, the binder compositions with the emulsifier-stabilized vinyl ester polymer dispersions of Examples 1 and 2 were more stable than the analogs of Example 3 stabilized with the protective colloid polyvinyl alcohol.

Here, with the non-ionic emulsifier, binder compositions that are significantly more storage-stable than with the anionic emulsifier were obtained, as examples 1 and 2 show. Determination of biodegradability:

To test the biodegradability, binder systems are usually applied to biodegradable reference materials. For this purpose, 25% by weight of the binder compositions (solid/solid) given in Table 2 were applied to cellulose powder and examined for aerobic biodegradability in accordance with ISO 14855-1. The test results are summarized in Table 2.

Table 2: Biodegradability: a) : VAE 1: vinyl ester polymer from example 1; VAE 2: vinyl ester polymer from Example 2; PSC 1: polysaccharide from example la; PSC 2: polysaccharide from example 1b;

Compared to the pure VAE binder of Comparative Example 4, the binder compositions of Examples 5 and 6 show significantly higher degradability and thus meet the requirement for biodegradability of >90%.

Determination of the wet and dry strengths of non-woven fabrics: On a thermally pre-bonded airlaid non-woven (75 g/m ² ; 88% fluff pulp and 12% PP/PE bicomponent fibers; 0.85 mm thickness), the water was applied to a solids content of 20% Diluted dispersion of the binder composition of the respective (comparative) example by means of a spray liquor with a semi-automatic spray unit according to the airless method (unijet 8001 E slot nozzles; 5 bar) is sprayed homogeneously on both sides and then in a laboratory through-air dryer (Mathis LTF; from Mathis, Switzerland) dried for 3 min at 160 °C (amount applied: 20 % by weight of binder composition based on the dry weight of binder composition and fleece).

For each tear strength test, 10 fleece strips (20 cm clamped length; 5 cm clamped length) were produced in the transverse direction to the machine production direction.

To measure the wet tensile strength, the strip samples were each stored in water for 1 minute before the measurement.

The wet and dry strengths were determined analogously to DIN EN 29073 (Part 3: Test methods for nonwovens, 1992) and the measurement samples were measured using a maximum tensile force measurement on a Zwick® 1445 testing machine (100 N load cell) with TestXpert® software version 11.02 (company . Zwick Roell) with a clamping length of 10011 mm, a clamping width of 1511 mm and at a deformation rate of 150 mm/min.

The formaldehyde content was determined according to ISO 14184-1.

The results of the testing are summarized in Tables 3 to 6.

Discussion of the dry strengths from Table 3:

The nonwovens of Examples 8, 9, 11 and 12 come surprisingly close to the strengths of the nonwovens of Comparative Examples 7 and 10. This is surprising because otherwise biopolymers usually lead to a considerable deterioration in strength.

The nonwovens of Examples 8, 9, 11 and 12 are pleasantly soft despite the polysaccharides themselves having a hardening effect and also show good elasticity (elongation).

In addition, the nonwovens of Examples 8, 9, 11 and 12 have a lower formaldehyde content than the nonwovens of Comparative Examples 7 and 10, which has a positive effect on the toxicological profile of the nonwovens. Table 3: Dry strength of nonwovens, without crosslinker: a) : VAE 1: vinyl ester polymer from example 1;

VAE 2: vinyl ester polymer from Example 2; BSC 1: polysaccharide from example la;

PSC 2: polysaccharide from example 1b; b) : Based on the dry weight of binder composition and fleece.

Table 4: Dry and wet strength of nonwovens, also with crosslinkers: a) : VAE 1: vinyl ester polymer from example 1;

VAE 2: vinyl ester polymer from Example 2; PSC 1: polysaccharide from example la;

PSC 2: polysaccharide from example 1b; b) Crosslinker 1: ARKOFIX® NZF (trade name of Archroma);

Crosslinker 2: KNITTEX® CHN (trade name from Huntsman); catalyst: citric acid; the data in % refer to wt. % dry matter; c) : Based on the dry weight of binder composition and fleece.

Table 5: Dry and wet strength of nonwovens, also with crosslinkers: a) : VAE 1: vinyl ester polymer from example 1; VAE 2: vinyl ester polymer from Example 2;

PSC 1: polysaccharide from example la;

PSC 2: polysaccharide from example 1b; b): Crosslinker 1: Arkofix NZF (trade name of Archroma);

Crosslinker 2: Knittex CHN (trade name from Huntsman); catalyst: citric acid; the data in % relate to % by weight of dry substance; c) : Based on the dry weight of binder composition and fleece.

Table 6: Dry and wet strength of nonwovens, also with crosslinkers: a) : VAE 1: vinyl ester polymer from example 1; VAE 2: vinyl ester polymer from Example 2;

PSC 1: polysaccharide from example la;

Crosslinker 2: Knittex CHN (trade name from Huntsman); Crosslinker 3: KYMENE 217 LXE (trade name of Solenis)

catalyst: citric acid; the data in % relate to % by weight of dry substance; c) : Based on the dry weight of binder composition and fleece.

Discussion of Tables 4 to 6:

The results show that the wet strengths of the nonwovens with vinyl ester polymers VAE and polysaccharides PSC could be further improved by adding crosslinkers and catalysts.

The nonwovens obtained were pleasantly soft despite the polysaccharides, which had a hardening effect per se, and also when crosslinking agents were used, and they also showed good elasticity (elongation).

Surprisingly, the formaldehyde content of the nonwovens could be significantly reduced, even when using crosslinking agents, which has a positive effect on the toxicological profile of the nonwovens. Only in the case of crosslinker 2 are the formaldehyde values significantly higher, since this splits off formaldehyde during crosslinking.

Claims

28

patent claims

1. Process for the production of textile fabrics by applying one or more binder compositions to fibers, characterized in that binder compositions contain one or more polysaccharides and one or more polymers of vinyl esters.

2. A method for producing textile fabrics according to claim 1, characterized in that polymers of vinyl esters on one or more monomers selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate , Vinyl pivalate and vinyl esters of a-branched monocarboxylic acids having 5 to 15 carbon atoms are based.

3. Process for the production of textile fabrics according to claim 1 or 2, characterized in that polymers of vinyl esters are additionally based on one or more monomers selected from the group consisting of acrylic acid esters or methacrylic acid esters of branched or unbranched alcohols having 1 to 15 carbon atoms, Dienes, olefins, vinyl aromatics and vinyl halides are based.

4. Process for the production of textile fabrics according to claims 1 to 3, characterized in that polymers of vinyl esters are additionally based on one or more ethylenically unsaturated monomers which are carboxyl, anhydride, silane, isocyanate, amide, hydroxyl, carry epoxy or NH groups. Method for producing textile fabrics according to claim 4, characterized in that s carboxyl-bearing monomers are selected from the group comprising acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid and maleic acid, anhydride-bearing monomers are selected from the group comprising Maleic anhydride and ethylenically unsaturated succinic anhydride derivatives, silane-bearing monomers are selected from the group comprising acryloxypropyltri(alkoxy)- and methacryloxypropyltri(alkoxy)-silanes, vinyltrialkoxysilanes and vinylmethyldialkoxysilanes, with ethoxy and ethoxypropylene glycol ether radicals, for example, being present as alkoxy groups Hydroxy-bearing monomers can be selected from the group comprising hydroxyethyl acrylate and methacrylate, hydroxypropyl acrylate and methacrylate, hydroxybutyl acrylate and hydroxybutyl methacrylate, epoxy-bearing monomers can be selected from the Group comprising glycidyl acrylate and glycidyl methacrylate, and monomers bearing NH groups are selected from the group comprising acrylamide, methacrylamide, N-alkylol-functional comonomers with a C 1 -C 4 -alkylol radical, C 1 -C 4 -alkyl ethers of N -Methylolacrylamide, N-methylolmethacrylamide and N-methylolallylcarbamate, C to C4-alkyl esters of N-methylolacrylamide, N-methylolmethacrylamide and N-methylolallylcarbamate. Process for the production of textile fabrics according to claims 1 to 3, characterized in that the polymers of vinyl esters are additionally based on one or more ethylenically unsaturated monomers carrying NH groups selected from the group consisting of N-methylolacrylamide, N-methylolmethacrylamide, N -Methylolallylcarbamate, C- to C4-alkyl ether of N-methylolacrylamide. Process for the production of textile fabrics according to Claims 1 to 6, characterized in that polymers of vinyl esters are stabilized with protective colloids. Process for the production of textile fabrics according to Claims 1 to 7, characterized in that polymers of vinyl esters are stabilized as an emulsifier. Process for the production of textile fabrics according to Claims 1 to 8, characterized in that polymers of vinyl esters are stabilized with nonionic emulsifiers. Process for the production of textile fabrics according to claim 1 to 9, characterized in that one or more polysaccharides are selected from the group consisting of starch, glycogen, cellulose, cellulose derivatives, chitosan, chitin, hyaluronic acid, glycosaminoglycans, alginates, galactans, cane sugar, maltodextrin and the products obtained by enzymatic or chemical cleavage or chemical modification of the aforesaid polysaccharides, glycoproteins and their derivatives and polysaccharides based on glucose, sucrose, fructose, galactose, lactose, maltose or mannose. Process for the production of textile fabrics according to Claims 1 to 10, characterized in that the binder compositions contain one or more crosslinking agents. Process for the production of textile fabrics according to Claim 11, characterized in that the binder compositions contain one or more catalysts.

13. Process for the production of textile fabrics according to Claims 1 to 12, characterized in that the fibers are natural, synthetic or other organic fibers, with synthetic fibers being selected from the group consisting of viscose, polyester, polyamide, Polypropylene or polyethylene fibers or their mixtures or their co-extrudates, and natural fibers are selected from the group consisting of wood, cellulose, leather, fur, wool, cotton, jute, flax, hemp , coir, ramie, sisal and cellulose fibers.

14. Textile fabrics obtainable by the process according to claims 1 to 13.

15. Textile fabric according to claim 14, characterized in that the textile fabric is biodegradable.

16. Binder compositions for textile fabrics containing one or more polysaccharides and one or more polymers based on one or more vinyl esters and one or more ethylenically unsaturated monomers, the carboxyl, anhydride, silane, isocyanate, amide, hydroxyl - Carry epoxy or NH groups are based.

17. Binder compositions for textile fabrics according to claim 16, characterized in that one or more crosslinkers are present.

18. Binder compositions for textile fabrics according to claim 17, characterized in that one or more catalysts are present.