MXPA98006156A - Relative textile binding composition in po - Google Patents

Abstract

Object of the invention is a crosslinkable textile binder composition in powder, for the production of molded parts or textile flat structures bound to polymer, containing a) a powder copolymer, obtainable by emulsion polymerization and subsequent drying, of one or various monomers of the group comprising vinyl esters, acrylic acid esters, methacrylic acid esters, vinylaromatic compounds and vinyl chloride and from 0.01 to 25% by weight, based on the total weight of the copolymer, of one or more ethylenically unsaturated monomers containing carboxylic groups, the copolymer having a glass temperature Tg or a melting point greater than 40 ° C, a molecular weight Mw of 60000 to 300000 and b) at least one powder compound, which contains two or more epoxide or isocyanate groups and has a melting point from 40§C to 150

Description

COMPOSITION FABRIC TEXTILE RETICULABLE IN POWDER The invention relates to a crosslinkable textile binder composition in powder form and to processes for the production of molded parts or flat textile structures linked to polymers using the textile binder composition. Flat textile structures »which are produced according to conventional methods for the production of non-woven fabrics, for example according to the process of extension with air (" airlay ")» wet spread ("wetlay") or extension by centrifugation ("spunlay") ) »Require a binding agent for the permanent fixing of the fibers and for the increase of the resistance capacity against mechanical stresses. These binding agents are usually based on synthetic compounds of high molecular weight and can, according to the prior art, be applied in the form of solids, for example, as granulated powder or fiber, or in the form of liquids, for example, as dispersion or solution. watery The high strength of the non-woven fabrics is the result of the union of the fibers by the polymers that adhere to the fiber and thus reinforce the fiber structure. From WO-A 90/14457 a method is known in which glass fibers are mixed after a carding step with thermoplastic powder. for example polypropylene »polyester or polyamide» and the fiber structure is then consolidated by heating and pressure. AU-B 36659/89 describes analogously a process for the consolidation of glass fiber materials by means of thermoplastic powders. In this case »the use of powders based on pol esters or polystyrene is recommended. The small resistance of the fiber structures thus bonded in contact with water or solvents is a disadvantage. Since the vitreous temperatures or the melting temperatures of the binding agents are often exceeded by the high temperatures, a long-lasting chemical cross-linking of the binding agents is necessary »in order to give the fiber structures dimensional stability at higher temperatures high Processes for the consolidation of fiber materials based on polyester fibers »polyamide or cotton with dispersions of self-crosslinkable polymers are known (US-A 4451315). In this way, it is in fact possible to obtain materials which have a high resistance, however, in the use of aqueous binders, the high cost of drying is a disadvantage. Additionally, the distribution of the binding agent in the fiber matrix is not problematic. The consolidation of powder crosslinkable copolymers based on phenol formaldehyde resins is described in US-A 4,612,224. In this binder system, the high emission of formaldehyde during the production and the use of the fiber materials thus consolidated is inconvenient. Self-crosslinkable redispersible dispersion powders based on codend vinyl esters or acid (meth) acrylic ester copolymers as an agent for bonding fibers are described in WO-A 94/20661. In this binder system it is disadvantageous that a considerable amount of water must be guaranteed in the fiber matrix for curing, which implies a high drying expense. Copolymers susceptible to curing by heating based on esters of acrylic acid and / or vinyl esters »which also contain esters of (meth) acrylic acid of mono- or polyfunctional hydroxycarboxylic acids and N-alkoxyalkyl-1 (meth) acrylamide as a component crosslinking "are described in US-A 4,129,545 as powder coating formers. EP-A 721004 discloses crosslinkable »water-dispersible» powders which contain not only film-forming polymers with at least one functional group »but also reactive components» which, after dispersion of the powder in water, form covalent bonds. Aqueous dispersions of the powder composition they are used for the production of water resistant coatings. The purpose of the invention was to develop a textile binder with which the disadvantages of the binding agents known from the prior art are avoided, such as lack of strength, high drying expense, deficient flow behavior and irregular distribution of the binder. An object of the invention is a cross-linkable textile binder composition in powder form for the production of molded parts or textile flat structures attached to polymers »containing a) a powder copolymer, which may be obtained by emulsionization and subsequent drying "of one or more monomers of the group comprising vinyl esters. esters of acrylic acid. esters of methacrylic acid, vinylaromatic compounds and vinyl chloride and from 0.01 to 25% by weight, based on the total weight of the copolymer. of one or more ethylenically unsaturated monomers containing carboxylic groups. the copolymer having a vitreous temperature Tg or a melting point greater than 40 ° C. a molecular weight Mw of 60000 to 300000. and b) at least one powder compound »containing two or more epoxide or isocyanate groups and having a melting point of 40ßC to 150 ° C. Suitable copolymers are those based on one or more monomers of the group comprising vinyl esters of unbranched or branched alkylcarboxylic acids with 1 to 15 C atoms, methacrylic esters and acrylic acid esters of alcohols with 1 to 10 C atoms. laromatics such as styrene and vinyl chloride. Preferred vinyl esters are vinyl acetate. vinyl propionate. vinyl butyrate. 2-ethyl hexanoate vinyl. vinyl laurate. 1-methyl vinyl acetate »vinyl pivalate and vinyl esters of branched monocarboxylic acids in a with 5 or 9 C atoms» for example VeoVa5r "or VeoVa9r". Preferred methacrylic acid esters or acrylic acid esters with methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate and 2-acrylate acrylate. -It is lhexi lo. It is essential that the composition of the copolymer be selected such that a glass temperature Tg or a melting point greater than 40 ° C is obtained, preferably from 55 ° C to 150 ° C. The vitreous transition temperature Tg and the melting point of the polymer can be determined in a known manner by differential scanning calorimetry (DSC). The Tg value can be calculated previously approximately by the Fox equation. According to Fox T.G., Bull. Am. Physics. Soc. »3» page 123 (1956) is fulfilled: 1 / Tg = s xA / TgA + x ^ / Tg. ,, + ... + x ^ / Tg ^. where? "represents the weight fraction (% by weight / 100) of monomer n. and Tg ^ is the vitreous transition temperature in degrees Kel in of the monomer homopolymer n. Tg values for homopolymers are presented in Polymer HandbooK. 23 edition. J. Wiley & Sons, New York (1975). Important for a uniform distribution of the binder powder in the fiber structure is a low melt viscosity of the binder powder. The melt viscosity of the binder powder is determined by the average molecular weight Mw and the molecular weight distribution Mw / Mn of the copolymer. The weight-average molecular weight Mw is between 60,000 and 300,000. The molecular weight and the molecular weight distribution can be adjusted in a known manner during the polymerization "for example" by the use of regulating substances and by the polymerization temperature »and can determined by gel permeation chromatography (GPC). Preferred copolymers are vinyl acetate / vinyl chloride copolymers. v1 m acetate / VeoVaS1". vinyl acetate / veVa9 * ~. methacrylate of butyl acrylate and butyl acrylate / butyl acrylate, which in all cases contain 0.01 to 25% by weight of the mentioned monomeric units containing carboxyl groups and whose composition is selected in such a way as to obtain the vitreous temperatures Tg or melting points mentioned above.Extremely unsaturated monomers containing appropriate carboxyl groups are ethylenically unsaturated mono- or dicarboxylic acids such as acrylic acid »methacrylic acid» maleic acid »fumaric acid and itaconic acid, preferably» the content of comonomer units containing carboxyl groups is 0.01 to 10% by weight »based on the total weight of the copolymer Optionally» the copolymers can contain 0.01 up to 10.0% by weight »based on the total weight of the copolymer of other adjuvant monomers from the group of acid amides ethylene-cationally unsaturated carboxylic acids »pre-acrylamide. from the group of ethylenically unsaturated sulphonic acids or their salts, preferably vinylsulphonic acid »from the group of the comonomers with multiple ethylenic unsaturation» for example divinyl adipate »diallyl maleate» allyl methacrylate or triallyl cyanurate and / or from the group of N-methylol (meth) acrylides "as well as their ethers such as isobutoxy or n-butoxy ethers. In a preferred embodiment, the copolymers they contain in all cases 0.01 to 2% by weight of acrylic acid and / or acrylamide. The preparation of the copolymers is carried out in a manner known per se preferably according to the emulsion polymerization process, as described, for example, in WO-A 94/20661, the corresponding publication of which forms part of the present invention. Request. For the production of the powders, the polymer dispersion obtained in this way is dried. Drying can be carried out by spray drying, lyophilization or coagulation of the dispersion and subsequent drying in a turbulent bed. Spray drying is preferred. Preferably the preparation of the copolymer and its drying are carried out without addition of protective colloid. As a crosslinker, powdered compounds are suitable, which contain two or more epoxide or isocyanate groups. with a melting point of 40 ° C to 150 ° C. Examples of suitable epoxy crosslinkers are those of the bisphenol-A type. that is, condensation products of bisphenol-A and epichlorohydrin or methylepiclorhydrin. Epoxy crosslinkers of this? can be obtained commercially, for example under the trade names Epicot or Eurepox. Suitable diisocyanates are likewise commercial products in common use, for example m-tetramethylxylenodiisocyanate (TMXDI) and methylenediphenyldiisocyanate (MDI). The content of the crosslinker is generally from O.l to 25% by weight, preferably from 4 to 12% by weight, based on the copolymer powder. In a preferred embodiment, the crosslinkable textile binder composition further contains a crosslinking catalyst. Suitable catalysts, for example, are powders, which are derived from triphenylphosphonium halides or quaternary ammonium compounds. Examples of these are methyl- bromide. ethyl- propyl- and buti 1-tripheni l osphonium. or the respective iodides and chlorides. Triphenylphosphonium halides with substituted alkyl radicals such as 2-carboxyethyl-1-bromide are also suitable. 3-bromopropyl- or formi 1meti 1-tripheni lphosphonium. Suitable quaternary ammonium compounds are tetrabutylammonium benzyl trimethylammonium salts and methyltributyl ammonium salts. The compounds mentioned can be obtained commercially and preferably used in amounts of 0.1 to 5% by weight, based on the copolymer powder. The production of the crosslinkable textile binder composition is carried out by mixing the powdered components in the indicated mixing ratios. For this purpose, known devices for mixing powders can be used.

A further object of the invention is a process for the production of molded parts or flat textile structures linked to polymers based on fiber materials »in which the fiber material is brought into contact with a polymeric powder binding agent and consolidated at a temperature of 100 ° C to 250 ° C and optionally under pressure, characterized in that a crosslinkable powder mixture containing a) a powder copolymer, obtainable by emulsion polymerization and subsequent drying, is used as the binder. or several monomers of the group comprising vinyl esters. esters of acrylic acid, esters of methacrylic acid, vinylaromatic compounds and vinyl chloride and from 0.01 to 25% by weight, based on the total weight of the copolymer, of one or more ethylenically unsaturated monomers containing carboxylic groups, the copolymer having a glassy temperature Tg or a melting point greater than 40 ° C, a molecular weight Mw of 60000 to 300000 »and b) at least one compound powder» containing two or more epoxide or isocyanate groups and has a melting point of 40 ° C up to 150 ° C. Natural or synthetic raw materials are suitable as fiber material. Examples of these are fibers of plastic material based on fiber-forming polymers such as viscose fibers »polyester» polyamide »polypropylene and polyethylene. Glass fibers are also suitable »ceramic fibers and mineral fibers. Examples of natural fiber materials are wood fibers »cellulose, wool, cotton, jute, flax, hemp, coconut, ramie and sisal. The fibers may also be used in the form of woven fabrics of yarns or in the form of non-woven fabrics such as extensions or knitwear. These non-woven fabrics can optionally be preconsolidated by mechanical means, for example by needling. For the bonding of the fibers, the powder mixture is generally used in an amount of 5 to 30% by weight. referred to fiber weight. For the production of the molded parts or flat structures, it is possible to proceed in this case in such a way that the fiber materials are mixed with the powder mixture and the mixture of fibers and powder is spread before the consolidation by means of the conventional processes. of the technology of non-woven fabrics, for example by means of an extension device with air »wet spread» direct spun or carded. Then. the flat textile structure is joined by heating »optionally with the use of pressure. You can also proceed in such a way that, before consolidation, the fibers extend flat. The processes for this are known and depend in the first place on the application to which the consolidated fiber material is intended. The fibers can be extended, for example, by means of an air-extension device, wet-spread, direct-spinning or carding. Optional entity. a consolidation by mechanical means, for example by cross-spreading, by means of needles or by consolidation with water jets, can be carried out before consolidation with the binding agent. The powder mixture is then sprinkled on the expanded fiber material by dusting the powder flat, punctually or as a pattern in partial fields and optionally being incorporated by needles into the fiber material. Subsequently, the fiber material is joined by application of temperature and optionally pressure. The powder textile binder is also suitable for the production of laminates, in which two fiber layers are bonded to one another, or a fiber layer is bonded to an additional substrate. In this case, it is possible to proceed in such a way that a layer of fibers is spread, the binder powder being previously incorporated by mixing or sprinkling after the extension, and an additional layer of fibers is applied thereon, for example by extension with air. Instead of the second fiber layer, another substrate can also be applied, for example a thin sheet of plastic material. The connection is then carried out using temperature and optionally pressure. With this method, for example, reclaimed cotton insulating materials which are durably coated with a fiber fleece as a covering fleece can be used. Another application is the bonding of glass fibers with cover sheets or decorative cover plates in the field of insulation for construction »or the production of shoe tips by sticking fabrics or fleeces with leather. The textile powder binder is particularly suitable for the production of bulky materials or fleeces. which find application, for example, as semifinished articles for the production of molded pieces of fiber materials or as padding, insulation and filtration sheets. For this, the binder or polyester is dusted into the fiber material and the material is consolidated by heating, preferably in a shaping mold. In a possible embodiment, the fiber structures are treated with water or superheated steam after mixing with the powder mixture or after dusting with the powder mixture. The powder-crosslinkable textile binder composition according to the invention is characterized against aqueous binders because expensive energetic drying and the disposal of waste water are avoided. Compared to the previously known powder binders, there are the advantages that a bond between the fibers is resistant to water and solvents, without the release of polluting substances, as in the case of phenylformaldehyde resins or in the case of powders. containing only N-methylalacrylamide as a crosslinker. The following examples serve for further clarification of the invention.

EXAMPLE 1 Production of a polymer powder containing carboxylic acid groups In a reactor with a volume of 3 liters, 838.8 g of deionized water and 6.7 g of sodium lauryl sulphate were charged beforehand and heated under nitrogen with stirring at SO ° C . At this temperature, the initiator solution (6.7 g of potassium peroxodisulfate and 218.4 g of water) was added to the reactor and the following compositions were metered into it from separate containers over the course of 4 hours: Dosage of monomer i: Raetacrylic acid 67.3 g Butyl acrylate 403.7 g Styrene 861.3 g Dodecyl mercaptan 6.7 g Dosage of monomer 2: Water 67.3 g Acrylamide (30%) 44.9 g Initiator dosage: Water 217.6 g Potassium Peroxodisulfate 6.7 g After the dosages »the polymerization was carried out for approximately 2 hours at 80 ° C. After cooling and adjusting the pH value to 8 with ammonia, the spray dispersion was dried. The vitrea temperature of this product was 59 ° C.

EXAMPLE 2 Production of a polymer powder containing carboxylic acid groups In a reactor with a volume of 3 liters, 855 g of deionized water and 6.7 g of sodium lauryl sulphate were charged beforehand and heated under a nitrogen atmosphere with stirring at 80 ° C. ° C. At this temperature the initiator solution (6.7 g of potassium peroxodisulfate and 217.4 g of water) was added to the reactor and the following compositions were metered in from separate containers over the course of 4 hours: Monomer dosage i: Acid methacrylic 67.2 g Butyl acrylate 403.4 g Styrene 860.5 g Dodecy 1 ercaptan 6.7 g Dosage of monomer 2: Water 67.3 g N-meti lolacri lick (48%) 28.0 g Initiator dosage: Water 217.4 g Potassium Peroxodisulfate 6.6 g After the dosages »the polymerization was carried out for approximately 2 hours at 80 ° C. After cooling and adjusting the pH value to 8 with ammonia, the spray dispersion was dried. The vitrea temperature of this product was 59 ° C.

EXAMPLE 3 Production of the powder mixture 98 g of the polymer powder containing carboxylic acid groups of example 1 were mixed in a powder mixer with 2 g of a multifunctional epoxy compound in powder form and with 0.5 g of tri eni leti phosphonium bromide » TEP EXAMPLE 4 Production of the polymer mixture 98 g of the polymer powder containing carboxylic acid groups of example 2 were mixed in a powder mixer with 2 g of a multifunctional epoxy compound powder and with 0.5 g triphenyl bromide Ifosphonium bromide. TEP EXAMPLE 5 A binder powder was produced based on a self-crosslinkable and redispersible dispersion powder according to the prior art according to WO-A 94/20661. This polymer powder was stabilized with a pol (vinyl alcohol) and contained N-methylol groups as crosslinkable groups. The molecular weight (GPC) was approximately 700000 g / mol. Production of the shaped bodies of fibers (with water): For the production of pressed plates, 115 g of regenerated cotton were mixed with 13.2 g in each case of the binder palladium of examples 1 to 5. They were spread on a surface of 24 x. 24 cm The fiber / powder mixtures were wetted with approximately 40 g of water by spray application and pressed afterwards at temperatures of approximately 10 ° C for 5 minutes, resulting in hard press plates of 2 mm thickness. or soft sheets 10 mm thick with a weight per unit area of approximately 2200 g / m2 and a bulk density of approximately 1115 kg / ra3 or respectively 223 kg / m3. Production of shaped bodies of fibers (dry): For the production of molded sheets were mixed 115 g of regenerated cotton with 13.2 g in each case of binder powder according to the examples and spread over a surface 24 x 24 cm. The fiber / powder mixtures were pressed immediately afterwards at temperatures of about 180 ° C for 5 min. with which hard plates of 2 mm thickness or soft plates of 10 mm thickness were obtained with a weight per unit area of approximately 2200 g / m2 and an apparent density of approximately 1115 kg / m3 or respective 223 kg / m3. Technical application tests: Maximum tensile strength »FMT: Stamped test specimens (dimensions: 10 x 100 mm) were stamped from the formed bodies of pressed fibers and tested at room temperature in a Zwick tensile testing machine. similar to DIN 53857. Water absorption: For the determination of water absorption »the shaped bodies of dry fibers (dimensions: 50 x 20 mm) were kept for 1 h or 24 h in water and absorption was determined gravimetrically weight as a result of swelling in water. Thermal stability: For the test with regard to the faculty of thermal stability »strips of 240 x 20 mm in length were cut. These strips were fixed horizontally on a flat base layer »in such a way that the strips protruded over a length of 100 mm beyond the edge of the base layer. In the IB In case of the hard shaped bodies (plate thickness 2 mm) a weight of 40 g was hung. while the soft shaped bodies (plate thickness: 10 mm) were left exposed only to the gravity of their own weight. The faculty of thermal stability was determined by measurement of flexion d after maintenance for 1 hour at T = 120 ° C. The results of the technical application test are shown in tables 1 and 2. The textile binding powders according to the invention (examples 3 and 4) have a significantly higher FMT value and a higher FMT value compared to non-crosslinked systems (examples 1 and 2). improved thermal stability (= less bending under thermal stress). Additionally. both tables indicate that the examples 3 and 4 corresponding to the invention present at room temperature a maximum traction force improved compared to the previous technique (example 5). The thermal stability of hard pressed and strongly compacted shaped bodies of 2 mm thickness should be considered really equal within the framework of the accuracy of the measurement. In soft-shaped "wadding-type" shaped fiber bodies, the thermal stability of the binder powders according to the invention (examples 3 and 4) is significantly improved compared to the prior art (example 5). In the production of the shaped bodies of fibers without the addition of water during the pressing, a clear improvement (= decrease) of the swelling in water in front of the prior art manifests itself in all cases.

COMBO 1 Testing of hard shaped bodies (weight per unit area: 2200 kg / m2, bulk density: 115 kg / m3) Example Pressed shaped bodies Wet dry pressed shaped bodies FMT StabiFMT Absorption Stability Thermal aigua absorption thermal water 1 h / 24 h 1 h / 24 h fN] [mm] [weight%] [N] [mm] [weight %] M Ex. 1 390 70 72/83 282 70 214/238 O Ex. 2 440 66 67/83 310 66 198/225 Ex. 3 948 21 48/57 560 22 139/161 Ex. 4 926 19 51/60 526 20 159/180 Ex. 5 326 20 68/79 165 41 253 / 284 COMBO 2 Tests of soft shaped bodies (weight per unit area: 2200 km / m2, bulk density: 223 kg / m3) Example Compressed shaped bodies in dry pressed shaped bodies FMT E Stabilized Abrassoorrhesion FMDT FM Absorption FMMTT Stability Absorption of thermal water thermal water 1 h / 24 h 1 h / 24 h [N] [mm] [weight%] [N] [ mm] [weight%] Ex. 1 15.2 16 602/621 15.4 15 728/739 Ex. 2 16.3 14 509/550 16.2 14 730/741 Ni Ex. 3 18.8 8 441/447 18.3 11 758/774 Ex. 4 17.9 7 423/439 18.3 8 721/752 Ex. 5 11.9 14 589/662 7.9 39 987 / 994

Claims (10)

NOVELTY OF THE INVENTION CLAIMS

1. Crosslinking textile binder composition in powder form for the production of molded parts or textile flat structures bound to polymers, containing a) a copolymer powder, obtainable by emulsion polymerization and subsequent drying of one or more monomers of the group comprising esters vinyl esters of acrylic acid esters of methacrylic acid vinyl aromatic compounds and vinyl chloride and from 0.01 to 25% by weight, based on the total weight of the copolymer of one or more ethylenically unsaturated monomers containing carboxylic groups, the copolymer having one vitreous temperature Tg or a melting point greater than 40 ° C »a molecular weight Mw of 60000 to 300000» and b) at least one compound powder »containing two or more epoxide or isocyanate groups and having a melting point of 40 ° C C up to 150 ° C.

2. The crosslinkable textile powder binding composition according to claim 1. characterized in that the composition further contains 0.1 to 5% by weight, based on the copolymer powder, of a powder crosslinking catalyst.

3. A cross-linkable textile powder binding composition according to claim 1 or 2. characterized in that a copolymer of the vinyl acetate / vinyl chloride group is used as the copolymer. vin acetate / VeoVad1-. vinyl acetate / VeoVag1"» methyl methacrylate butyl acrylate and styrene / butyl acrylate, which in all cases contain 0.01 to 25% by weight of the monomer units containing carboxyl groups mentioned. Crosslinkable textile binder composition in powder form according to claim 1, characterized in that "as monomer units containing carboxyl groups" are those of the acrylic acid group »methacrylic acid, maleic acid, fumaric acid and itaconic acid. powder according to claim 1 to 4, characterized in that the copolymer further contains 0.01 to 10.0% by weight, based on the total weight of the copolymer »of one or more monomers of the group of the ethylenically unsaturated carboxylic acid amides» of the sulfonic acid group ethylenically unsaturated or their salts 'from the group of the comonomers with multiple ethylenic unsaturation' and group of the N-methylol (meth) acri lamides »as well as their ethers such as isobutoxy- or n-butoxyethers. 6. The cross-linkable textile binder composition according to claim 1, characterized in that acrylic acid and / or acri-lamide are present in an amount of 0.01 to 2% by weight in all cases. 7. Process for the production of molded parts or flat textile structures linked to polymers based on fiber materials »in which the fiber material is brought into contact with a polymeric binder powder and consolidated at a temperature of 100 ° C up to 250 ° C and optionally under pressure, characterized in that a crosslinkable powder mixture according to claim 1 to 6 is used as the binding agent. 8. Process according to claim 7, characterized in that one or several fiber materials are used as the fiber material. from the group of viscose fibers, polyester. polyamide. polypropylene or polyethylene. glass fibers. ceramic fibers, mineral fibers, wood fibers, cellulose »wool, cotton, jute, flax» hemp, coconut »ramie and sisal» in the form of woven textile products »of yarns, or in the form of non-woven fabrics such as extensions or knitwear. Process according to claim 7 or 8. characterized in that the crosslinkable powder mixture is used in an amount of 5 to 30% by weight, based on the fiber weight. 10. Process according to claim 7 to 9. characterized in that the fiber structure is treated with water or steam superheated after mixing it with the powder mixture or after sprinkling the powder mixture.