MXPA01005687A - Method of coagulating aqueous pur dispersions containing dispersed therein reactive or secondary cross-linked polyurethane, the products obtained thereby and their use - Google Patents

Abstract

The invention relates to a method of coagulating aqueous PUR dispersions, to the coagulation products obtained thereby and to the use of the coagulated PUR dispersions. The PUR dispersions that are used according to the inventive method are reactive PUR dispersions or PUR dispersions thathave been subjected to a secondary cross-linking reaction. The inventive methods comprise the production of films, the coating of various materials and the partial or complete impregnation of non-wovens, wovens or other flat structures for the purpose of stabilization.

Description

PUR containing reactive polyurethane or post-reticv1? '*.' '1? fi-sp-rsadof products thus obtained and their use DESCRIPTION OF THE INVENTION The invention relates to a process for the coagulation of PUR dispersions, to the cagulation products thus obtained and to the use of the coagulated PUR dispersions. Suitable reactive or post-crosslinkable PUR dispersions are suitable as PUR dispersions for the process according to the invention. The processes according to the invention comprise the production of films, the coating of the most diverse materials and the partial or total impregnation of layers, fabrics or other flat articles for reinforcement purposes.

The coagulates produced by the process according to the invention are suitable for application, for example, in the sectors of clothing, protective clothing, cover material and shoe lining, protective gloves, leather goods and quilting, metal coating, medicine and hygiene items, etc. The manufacture of coated textile flat articles, such as, for example, synthetic leather has been known for a long time. The coating agent is applied in one or more layers by the direct coating process or by the transfer process on the substrate. The REÍ: 129632 coated textile flat items can be used for the manufacture of outerwear, cover material and shoe lining, leather goods and quilting, etc. It is also known to manufacture, for example, gloves with latex dispersions or, more recently, due to allergies that occur against latex, with polyurethane dispersions, especially causing the use of polyurethane dispersions for coagulation biggest technical problems The flexibility, resistance to traction and softness play, among other factors, a decisive role with regard to the comfort sought in the manufacture of coated textile flat items, qualitatively of first quality, since the rigid flat items lack comfort. If, in the production of coated textile flat articles, a bonding of the fiber crossing points is not avoided, flexibility is lost and there is a danger that the bond between the textile fibers and the binder will be destroyed in the bending stress. Unwanted sticking of fiber bundles and fiber crossing points can be avoided if the flat textile articles are treated, eg, with aqueous dispersions of organic binders and these then coagulate. In this way a high tensile strength and a greater softness of the coated textile flat articles is achieved.

The following coagulation methods are known: Bath coagulation, in which the substrate is coated with a binder dissolved in an organic solvent (eg DMF, DMAC, DMSO, THF) and the product thus obtained is passed through from a bath of a non-solvent (eg water) miscible with the solvent; Due to the extraction of the solvent by the non-solvent, coagulation takes place. The drawbacks of this process lie in particular in the necessary and expensive measures for the safe handling, treatment and recovery of very large quantities of solvent. Coagulation by evaporation, which is based on the use of a volatile solvent and a less volatile non-solvent for the binder; first, it is released by moderately preferentially heating the solvent, so that the binder coagulates due to the constantly increasing proportion of non-solvent; as a disadvantage, it also results from the equally necessary use of large quantities of solvent, the enormous technical deployment required and the very limited possibilities for optimization by means of the process parameters. - Coagulation with salts, acids or electrolytes is carried out by immersion of the coated substrate or, as in the case of gloves, of the mold first submerged in the dispersion, in a concentrated salt solution or in water or another liquid mixed with acid, with which the binder coagulates due to the high content of electrolyte; The disadvantages of this procedure lie in the complicated technical execution and above all in the high formation of charged wastewater. The prepolymerization method, according to which a substrate coated with an isocyanate prepolymerizate is immersed in water and then, when C02 is dissociated, a polyurea with a porous structure is formed. It turns out to be a drawback, among others, the very high reactivity of the formulations and the very short processability times associated therewith. The possible coagulation by elevation of temperature for non-post-crosslinkable adjusted heat sensitive binders, which often leads to unacceptable results. In short, the indicated methods either require long times until the total elimination of the solvents is obtained, a considerable cost for the separation and recovery of solvents and non-solvents, the evacuation of wastewater laden with acid or saline inputs, or they do not lead in all cases to qualitatively acceptable results. The object of the invention has thus been to provide a new process for aqueous coagulation and products suitable for this without the drawbacks described. Afterwards it should be possible, using an aqueous dispersion without or only with a small content of organic solvent and without using baths of salts, acids or other electrolytes to obtain high quality products in a simple process. It has surprisingly been found that the coagulation according to the invention can be achieved by using post-crosslinkable aqueous polyurethane dispersions. The use of the term "polyurethane" also includes polyurethane-polyurea. Accordingly, a process for the coagulation of post-crosslinkable dispersions is characterized by the fact that post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 50 to 120 ° C, forming at least partially crosslinked polyurethane or stable gel. Preferably the process according to the invention is carried out at a temperature of 75 to 98 ° C. The process according to the invention for the coagulation of post-crosslinkable PUR dispersions is characterized in that post-crosslinkable dispersions having a content of a) blocked isocyanate groups (calculated as NCO = 42) of 0.1 to 7.5% in weight, preferably from 0.9 to 2.0% by weight, and b) a content of at least one polyamine with at least two primary and / or secondary amino groups attached (cyclo) aliphatically and / or hydroxyamine, the ratio of equivalents of blocked isocyanate groups a) to amino groups from b) to 1: 0.5 to 1: 1.5, preferably 1: 0.7 to 1: 1 , 2, with particular preference 1: 0.9 to 1: 1.1, are precipitated by heat treatment at a temperature of 50 to 120 ° C, preferably of 75 to 98 ° C, forming an at least partially cross-linked polyurethane or gel stable Another object of the invention are the coagulates produced according to the process according to the invention. In the process according to the invention for the coagulation of post-crosslinkable dispersions, post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 50 to 120 ° C, at least one partially crosslinked polyurethane or stable gel being formed, the dispersions being characterized in that used have a) a content of blocked isocyanate groups (calculated as NCO = 42) of 0.1 to 7.5% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two primary amino groups and / or secondarily (cyclically) bound, the ratio of equivalents of blocked isocyanate groups of a) to amino groups from b) to 1: 0.5 to 1: 1.5, preferably being precipitated by heat treatment at a temperature of 75 to 98 ° C post-crosslinkable dispersions forming an at least partially crosslinked polyurethane or stable gel, characterized in that the dispersions used have a) a group content blocked ocyanate (calculated as NCO = 42) of 0.25 to 5% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two primary and / or secondary amino groups attached (cyclo) aliphatically, ascending the ratio of isocyanate group equivalents blocked from a) to amino groups from b) to 1: 0.7 to 1: 1.2, with particular preference being characterized in that they are precipitated by heat treatment at a temperature of 75 to 98 ° C post-crosslinkable PUR dispersions forming at least partially crosslinked polyurethane or stable gel, further characterized in that the dispersions used have a) a content of blocked isocyanate groups (calculated as NCO = 42) of 0.7 to 2% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two primary and / or secondary amino groups linked (cyclo) aliphatically, the ratio of equivalents of blocked isocyanate groups a) to amino groups of b) to 1 : 0, 9 a 1: 1.1. In a preferred process variant according to the invention for the coagulation of post-crosslinkable dispersions, dispersions based on hydrophilic raw materials, in particular hydrophilic polyols, are used, and in this way water vapor permeable coagulates are formed. The coagulable post-crosslinkable polyurethanes used in the process according to the invention, present in the form of aqueous dispersions or emulsions are reaction products of 1) at least one organic di- or polyisocyanate, 2) at least one polyhydroxy compound with a molecular weight up to 16,000, 3) ionic or potentially ionic hydrophilizing agents and / or nonionic hydrophilizing agents, 4) blocking agents for isocyanate groups and 5) optionally mono-, di- or triacenes of low molecular weight as chain-terminating components, chain extenders or chain branching agents, and further 6) being contained in the dispersion polyamines crosslinking agents, the components 3) being contained in amounts such that a stable dispersion is formed. The coagulable post-crosslinkable polyurethane dispersions used in the process according to the invention, present in the form of aqueous dispersions or emulsions are preferably reaction products of 1. 9 to 30% by weight of at least one organic diisocyanate, 2. 40 to 85% by weight of at least one polyhydroxylic compound at least difunctional with a molecular weight of 350 to 4,000, 3. 4 to 22% by weight of ionic or potentially ionic hydrophilizing agents and / or nonionic hydrophilizing agents, 0.5 to 5% by weight of blocking agents for isocyanate groups and 5. 0 to 5% by weight of low molecular weight mono-, di- or triamines as chain terminating components, chain extenders or chain branching agents , plus 6. the content of non-ionic hydrophilicizing agents 3) being 3% by weight being contained in the dispersion of 1 to 6% by weight of crosslinking polyamines. For the process according to the invention, reactive or post-crosslinkable dispersions are used, preferably PUR dispersions. Compounds constituting such PUR dispersions can be: 1. Di- and / or organic polyisocyanates, such as, for example, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2-methyl-pentamethylene diisocyanate, 2, 2, 4-trimethe 1 hemethylamide (THDI), dodecanomethylene diisocyanate, 1,4-diisocyanatocyclohexane, 3-isocyanatomethyl-3, 3, 5-trimethylcyclohexyl isocyanate (i) sophor ondii socianat or = IPDI), 4,4'-diisocyanatodicyclohexylmethane (®Desmodur W), 4,4'-diisocyanato-3,3'-dimethyl-cyclohexylmethane, 4,4'-di isocianat or dicyclohexylpropane- (2, 2) , 1,4-diisocyanatobenzene, 2,4- or 2,6-diisocyanatotoluene or mixtures of these isomers, 4,4'-, 2,4'- or 2,2'-diisocyanatodiphenylmethane or mixtures of the isomers, 4,4 '- diisocyanatodiphenylpropane- (2,2), p-xylylene-diisocyanate and a, a ', a'-tetramethyl-m- or -p-xylylenediisocyanate (TMXDI) as well as mixtures formed by these compounds. For the purpose of modification, small amounts of trimers, urethanes, biurets, allophanates or uretdiones of the indicated diisocyanates can also be used. Especially preferred is MDI, Desmodur W, HDI and / or IPDI. Polyhydroxy compounds having per molecule 1 to 8, preferably 1.7 to 3.5, hydroxyl groups and a molecular weight (average) of up to 16,000, preferably up to 4,000. In this regard, both defined low molecular weight polyhydroxy compounds, such as, for example, ethylene glycol, 1,2-, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, glycerin, are considered. , reaction product of 1-hydrazine + 2-propylene glycol as well as oligomeric polyhydroxy compounds or polymers with molecular weights of 350-10,000, preferably 840 to 3,000. The high molecular weight hydroxylic compounds comprise the hydroxypolyesters, hydroxypolyethers, hydroxypolyte ions, hydrotypes 1, hydroxypolycarbonates and / or hydroxypoliesteramides known per se from the chemistry of polyurethane, preferably those of average molecular weights from 350 to 4000. , with special preference those of average molecular weights of 840 to 3,000. Especially preferred are hydroxypolycarbonates and / or hydroxypolyethers. With them it is possible to prepare coagulates which are particularly stable to hydrolysis. Ionic or potentially ionic hydrophilicizing agents having an acid group and / or an acid group present in salt form as well as at least one isocyanate-reactive group, for example an OH or NH2 group. Examples of these are the Na salt of ethylenediamine-β-ethyl-sulphonic acid (AAS salt solution), dimethylolpropionic acid (s) (DMPS), dimethylolbutyric acid, aliphatic diols having sulfonate-Na groups to DE-A 2 446 440, hydroxypivalic acid or adducts of 1 mole of diamine, preferably of isophoronediamine, and 1 mole of a α, β-unsaturated carboxylic acid, preferably acrylic acid (see German patent application 19 750 186.9) . Preferred are hydrophilizing agents containing carboxylate and / or carboxyl groups of the aforementioned type or dimethylolpropionic acid. Nonionic hydrophilicizing agents in the form of polyoxyethylene or polyoxyethylene propylene alcohols with molecular weights of 300 to 5,000. Especially preferred are monohydroxyfunctional oxyethylene / oxypropylene polymers based on n-butanol with 35 to 85% by weight of ethylene oxide units and a molecular weight of 900 to 2,500. A content of at least 3, especially preferred of at least 6% by weight of nonionic hydrophilizing agent is preferred. Block agents for isocyanate groups, such as, for example, oximes (acetone-, butanone- or cyclohexanone oxime), secondary amines (diisopropylamine, dicyclohexylamine), heterocycles with NH acid (3,5-dimethylpyrazole, imidazole, 1,2,4-triazole), esters with CH acid (C este C alkyl esters, malonic acid, ethyl acetoacetate) or lactams (e-caprolactam). Butanone oxime, diisopropylamine and 1,2'-triazole are especially preferred. Polyamines as chain extenders inserted to give the polymer backbone of the post-crosslinkable dispersions special properties. This includes, for example, the polyamines exhibited at 6. The non-functional diaphragm hydrophilizing agents indicated in 3a) are also suitable as inserted chain extenders. Ethylenediamine, IPDA and H12MDA are especially preferred. Crosslinking polyamines for post-crosslinking under thermal influence. Here, preference is given to aliphatic or cycloaliphatic diamines, although polyamines tri or polyfunctional polyamines can also be used for the attainment of special properties. In principle, it is also possible to use polyamines with additional functional groups, for example OH groups. The crosslinking polyamines which, at normal to low ambient temperatures, eg from 20 to 60 ° C, are not inserted into the polymer backbone can be added to the mixture or immediately in the preparation of reactive dispersions or a later chosen moment. Examples of suitable aliphatic polyamines are ethylenediamine, propylene-diamine-1,2 and 1,3, tetramethylenediamine 1,4, hexamethylenediamine-1,6, the mixture of 2,2,4- and 2,4,4- isomers. tr ime ti lhexame ti 1 endi amine, 2-methyl-pentamethylenediamine and bis- (β-aminoethyl) amine (diethylene triamine). Examples of suitable cycloaliphatic polyamines are: Araliphatic polyamines, such as, for example, 1,2- and 1,4-xylylenediamine or a, a, a ', a'-tetramethyl-1, 3- and -1,4-xylylenediamine, can also be used as crosslinking agents. Particularly preferred are diamines 3, 3, 5 - 1 r ime t i 1 - 5 -amino tome 1 c i c 1 ohe x i 1 amine (IPDA) and '4,4'-diaminodicyclohexyl methane (H12MDA). The constituent components listed above are found in the reactive dispersions in the following preferred ranges, with the addition of all of the 6 components providing 100% solid matter of a dispersion: 1.) Polyisocyanates 9.0 to 30.0% by weight, especially preferably 13.0 to 20.0% by weight 2. ) Polyhydroxylic compounds 40.0 to 85.0% by weight, especially 55.0 to 75.0% by weight 3.a) Ionic hydrophilizing agents 1.0 to 5.0% by weight, particularly preferably 2.5 to 4.0% by weight 3. b) Nonionic hydrophilizing agents 3.0 to 17.0% by weight, particularly preferably 6.0 to 12.0% by weight 4. Blocking agents 0.5 to 5.0% by weight, particularly preferably 1.5 to 4.0% by weight . ) Chain lengthening polyamine 0 to 5.0% by weight, particularly preferably 0 to 1.5% by weight 6. Polyamine crosslinker 1.0 to 6.0% by weight, particularly preferably 2.0 to 4.0% by weight The post-crosslinkable reactive dispersions can be prepared by discretional processes, for example according to the following procedure. In the usual way, an NCO prepolymer is prepared in a synthesis of one or several steps, in which an excess of diisocyanate (1.) is stirred in the molten state with hydroxyl polyethers / polycarbonates (2.), optionally in the presence of a hydroxyalkylcarboxylic acid, eg DMPS (3.a) and a monofunctional polyoxyethylene alcohol (3.b) at a temperature of 60 to 110 ° C for about 3 to 6 hours, until the calculated NCO content is measured. After this, the highly viscous NCO prepolymer is diluted with acetone, for example half of the NCO groups present are reacted at ca. 45 ° C with a blocking agent (4.) and the rest of the NCO groups with a diamine, for example IPDA, lengthening the chain, or, if in the step of the previous prepolymer no potentially ionic dispersant had been incorporated, as eg DMPS, with a potentially ionic dispersant, eg the adduct of 1 mole of IPDA and 1 mole of acrylic acid. As soon as no NCO group is detected in this acetone solution, the crosslinking polyamine (6.) is added. The amount of crosslinking polyamine corresponds to the ratio of its NH 2 equivalent to the blocked NCO equivalents. In the case described, the crosslinking polyamine also adopts the role of the salt-forming cation with the carboxylic acid (3.a) inserted and confers, together with the constituent component (3.b), the polyurethane described, the necessary hydrophilicity. Now it can be added to the acetonic solution, stirring, water. A dispersion of blue tone is thus formed. After removal of the acetone at 45 ° C and in a vacuum, the ready-to-use reactive dispersion is obtained. By simultaneously using the crosslinker .6.) As a neutralizing agent for ionic groups of the compounds (3.a) coagulates of special high quality or particularly coagulable dispersions are obtained. This procedure is therefore preferred. Another embodiment consists in that a dispersion is prepared according to the described process and the crosslinking polyamine is added only before processing the dispersion. In the above-described process, the preparation of reactive dispersions according to the acetone process is described, which generally leads to a good reproducible quality of the product. However, another solvent, for example N-methylpyrrolidione, can also be used instead of acetone. A compendium on dispersions of PUR and its procedures can be found in "Rosthauser and Nachtkamp, Waterbone Polyurethanes, Advances in Urethane Science and Technology, vol 10, pp. 121-162 (1987)". In principle, the products according to the invention can also be produced without the use of organic solvents. Surprisingly it has been found that by choosing suitable raw materials, post-crosslinkable reactive polyurethane dispersions with very good water vapor permeability can also be prepared. In this case, for example, polyoxyethylene diols or hydrophilic thiols are used as component 2) of the polyurethane.or hydrophilic polyoxyethylene / polyoxypropylene diols or triols and / or hydrophilic polyols or diesterols based on dicarboxylic acids and, for example, tetraethylene glycol. The hydrophilic polyols 2) can be used in this connection either as polyols 2) alone or together with hydrophobic polyols 2). In a preferred embodiment such hydrophilic components (2) are contained together with the hydrophilizing component (3.a) and / or (3.b) in the coagulable polyurethane. The solids content of the dispersions to be used according to the invention can be between 5 and 60%, with a viscosity of about 0.01 to 100 Pa.s. The viscosity can be adjusted with thickeners, such as Mirox®AM, Walocel® MT 6000 PV, Rheolate® 225, Collacral® VL or others, the concentration, if appropriate, by dilution with water, to the respective requirements of the dispersions, to the processing conditions as well as the desired properties of the final product. The post-crosslinkable reactive polyurethane dispersions used according to the invention can be further modified according to the mode of application of the final product. Thus, for example, dyes, pigments and / or carbon black, ultraviolet filter substances, stabilizers against oxidation, haptic agents, among others, can be used. Other dispersions, such as, for example, polyurethane dispersions according to the prior art, dispersions of polyacrylate, polyacrylonitrile, polyester, polyepoxide, polybutadiene, polystyrene, among others, for the attainment of special properties, up to 50% can also be used. , preferably up to 25%. The coagulates obtained according to the invention can be processed directly in / out of the reaction solution in situ to form flat articles.

Accordingly, another object of the invention is flat articles manufactured from the coagulates obtained according to the invention. The flat articles obtained according to the invention can also be subsequently colored by known methods. The characterization of the dispersions to be used according to the invention is carried out by determining the content of non-volatile substances, the viscosity and determining the tensile and elongation properties of the extended film strips. The application of the post-crosslinkable reactive dispersions to be used according to the invention can be carried out, for example, by pouring, spraying, dipping, spraying, filling, with a doctor blade or roller or by padding, the dispersions being used in the liquid or foamed state. In general, after application according to one of the indicated methods, it is coagulated by immersion in hot water from 50 ° C to 120 ° C, preferably from 75 ° C to 98 ° C, with hot steam, for special applications by filling of forming parts with hot water, heating the parts of the mold between 120 ° C and 130 ° C or in a furnace with a dryer by radiation or high frequencies and then drying and condensing at a temperature of 60 ° C to 180 ° C, preferably from 100 ° C to 160 ° C. Suitable carrier materials are textile flat articles, flat metal substrates, glass, ceramics, leather and plastics such as PVC, polyolefins, polyurethane or the like.

By textile flat articles in the sense of the present invention, it is understood, for example, knitted or unbonded fabrics, knits or webs. The textile flat articles can be constituted by synthetic, natural fibers and / or their mixtures. Basically, discrete fiber textile materials are suitable for the process according to the invention. Special objects of the process according to the invention are the coating of support materials, the coating of substrates, the production of flat and shaped sheets, such as, for example, gloves, protective covers, among other applications, the reinforcement of layers and the endowed general for purposes of haptic variation. The coagulate that is formed is so resistant that the process of precipitation can be carried out after application in a saponification bath and "splitting" (NaOH at 3%) with microfibers, a part of the polyester present being able to saponify and drag dissolved. This leads to particularly pleasant and soft touch flat items. Flat items coated or filled on one or both sides can be polished subsequently and are then especially soft. Also a mechanical treatment in a rotating drum increases the softness.

EXAMPLES Example 1 (according to the invention) The preparation of a reactive PUR dispersion based on MDI as an isocyanate component, butanone oxime as a blocking agent and 4,4'-diaminodicyclohexylmethane as a post-crosslinking polyamine is described. Formulation 110.0 g (0.110 equiv.) Of a polyether OH OH 56, prepared by propoxylation of trimethylolpropane 110.0 g (0.110 equiv.) Of a polycarbonate of OH 56 Index, based on 1,6-dihydroxyhexane 80.0 g (0.080 equiv.) Of a polypropylene glycol of OH value 56 49.5 g (0.022 equiv.) Of a monovalent polyether OH 25 (dispersant), prepared by ethoxy- and propoxylation (in blocks of approx. 50/50%) of n-butanol 76.5 g (0.612 equiv. Of 4,4'-diisocyanatodiphenylmethane (MDI) 12.18 g (0.14 equiv.) Of butanone oxime 60.40 g (0, 15 equiv.) Of dispersant (30% aqueous solution of the adduct of 1 mole of acrylic acid and 1 mole of IPDA, 1 equivalent of NH / NH2 = 403 g, 1 add the aqueous dispersant solution and stir at 45 ° C for about 1 hour until the NCO group is no longer detectable, then H12MDA is added to the casting and dispersed with water, the water being poured with good agitation at short intervals into the acetonic solution After distilling off the acetone (45 ° C, 250-20 mbar, approx. 3-4 hours) a milky blue dispersion with a viscosity (23 ° C) of approx. 600 mPa.s and a solid matter of 45%. g-pi lp 2 (according to the invention) This reactive dispersion differs from that of Example 1 only in the blocking agent. Instead of butanone oxime, 13.44 g (0.14 equiv.) Of 3,5-dimethylpyrazole are now contained. The blue shade dispersion with a solids content of 45% has a viscosity (23 ° C) of approx. 4,400 mPa.s. F. otn i >; ^ (according to the invention) This reactive dispersion differs from that of Example 1 only in the blocking agent. Instead of butanone oxime, 14.14 g (0.14 equiv.) Of diisopropylamine are now contained. The stable blue shade dispersion with a solids content of 45% has a viscosity (23 ° C) of approx. 2,200 mPa.s F. oniplf. ? (according to the invention) The preparation of a reactive PUR dispersion based on IPDI as isocyanate component, 1,2,4-triazole as a blocking agent and 4,4'-diaminodicyclohexylmethane as crosslinking polyamine is described. Formulation 185.0 g (0.185 equiv.) Of a polyether OH OH 56, prepared by propoxylation of trimethylolpropane 230.0 g (0.230 equiv.) Of a polybutylene glycol of OH Index 56 70.0 g (0.070 equiv.) of a polyether glycol having an OH number of 56, prepared by propoxyethoxylation (blocks of 50/50%) of water 34.0 g (0.015 equiv.) of a monovalent polyether OH 25 (dispersant see Example 1) 100 , 0 g (0.90 equiv.) Of isophorone diisocyanate (IPDI) 12.07 g (0.175 equiv.) Of 1,2,4-triazole 60.45 g (0.150 equiv.) Of the potentially ionic dispersant according to Example 1 , 37 g (0.075 equiv.) Of isophoronediamine (IPDA) - 18.40 g (0.175 equiv.) Of 4,4'-diamino-dicyclohexylamine (H12MDA or PACM 20) 968.68 g of demineralized water 1. 684.97 g of dispersion (at 40%) 673.97 g of proportion of calculated solid matter 1,011.00 g of water content viscosity at 23 ° C: approx. 1,000 mPa.s The above dispersed polyurethane (100%) has a content of blocked NCO groups, calculated as NCO 42, of 1.09% by weight NH2 groups, calculated as NH2 / 16, of 0.41% by weight IPDI is reacted together with the dehydrated hydroxyl compounds at 105 ° C for approx. 5 hours, until the NCO content is reduced to 2.67%, the calculated being 2.7%. After this the white triazole flakes are added and stirred for approx. 1 hour at 100 ° C.

There is an NCO content of 1.4%, with the calculated value of 1.49%. It is then diluted with 500 g of acetone and mixed at approx. 45% with the aqueous dispersant solution and 15 minutes later with IPDA. It is then stirred for 30 minutes at 45 ° C and no NCO group is detected any more.

(IR spectrum). It can now be added by stirring the crosslinking polyamine PACM 20 and dispersed 10 minutes later by adding water. After the distillation of acetone (45 ° C, 250-20 mbar, approx. 3-4 hours) a storage-stable milky blue dispersion (50 ° C) with a viscosity is obtained (23 ° C) of approx. 1,000 mPa.s and a solids content of 40%. t. -amp 5 (according to the invention) The preparation of a reactive PUR dispersion whose coatings are permeable to water vapor is described. The synthesis differs only in non-essential aspects from that described in Example 1. The variation concerns the composition of the three polyol components as follows. All other components correspond to the quantity and type indicated in Example 1. 100.0 g (0.100 equiv.) Of a polyether OH OH 56, prepared by propoxylation of trimemethylolpropane 100.0 g (0.100 equiv.) Of a polycarbonate of OH 56, based on 1,6-dihydroxyhexane 100.0 g (0.100 equiv.) Of a polypropylene / ethylene glycol (proportion of polyethylene glycol of approximately 50%) of OH number 56 The dispersion of blue tonality, almost a solution, with a solids content of 35% has a viscosity (23 ° C) of approx. 2,000 mPa s. t. < - lt I have applied 1 Rt »? r» 'napkin yarn A non-pretreated, non-glued batt based on polyamide and polyester fibers is subjected to a scarf treatment with a dispersion according to Example 1 diluted with water to a content of solid material of 10% and treated in a flat state in a hot water bath at 95 ° C, with which the polyurethane coagulates. After this the napa is crushed and dried at 120 ° C. For film formation, it is then condensed at 150-160 ° C. With sufficient drying efficiency both processes can be carried out in one step. The initial gel solidifies in the thermal treatment giving a dry film with resistance capacity. The coagulate resists surface migration of water during drying and does not migrate to the surface. By means of an additional mechanical treatment such as a rotating drumBy polishing, polishing or adding sizing agents, multiple variations of the touch are achieved. By incision of the nappa in a similar way to the manufacture of leather the diameter of the nappa can be easily regulated. Application example 2 Bo <; - Nappa with nappa with subsequent "splittins" An unpainted nappa based on polyamide and polyester fibers is subjected to a scarf treatment with a dispersion according to Example 2 diluted with water at a solids content of 10% and coagulates in a bath with 3% caustic solution at 95-100 ° C. At the same time the polyester fiber contained in the web is partially saponified and dissolved. The duration of the treatment is 45 minutes. The napa is then washed well with water, crushed and dried at 120 ° C. It is then condensed at 160 ° C. After this, each side is polished once or twice. A textile flat article with a particularly pleasant, soft touch is obtained. Application layer 3 Lacquer of metal and / or glass bottles The metal or glass bodies are heated directly or indirectly with a hot liquid at 90-110 ° C and immersed in a dispersion prepared according to Example 3 diluted to 20% . The thickness of the film can be controlled by the immersion time and the concentration of the PUR dispersion. The gel formed is then dried without touching it at 60-80 ° C and then condensing at 160 ° C. By adding aqueous preparations of pigments a series of interesting chromatic nuances can be obtained. The coatings are characterized by very good adhesion values. Application example 4 Coating of cloth gloves as gloves d * < -y »v ^? o The fabric scrap extends over the glove mold and is immersed with it in the dispersion prepared in accordance with Example 5 and adjusted to a viscosity of 2,000-3,000 mPa.s with a thickener for commercial use. The thickness of the dispersion prevents it from crossing it when submerged. After immersion, the outside of the glove impregnated on the mold is immersed for 10 seconds in hot water at 60-95 ° C, then dried at 120 ° C and condensed at 160 ° C. As required the post-crosslinkable dispersions are mixed with pigment preparations for the manufacture of colored gloves. I have applied 5 Gloves or protective covers without support A mold heated at 80-120 ° C is immersed in the dispersion according to Example 4 diluted to a solids content of 25%. Depending on the desired film thickness, the residence time is 5-20 seconds. After this the gel is dried on the mold at 80-100 ° C and then condensed at 160 ° C. A film free of pores with very good elasticity and strength is formed.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (19)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. Process for the coagulation of post-crosslinkable dispersions, characterized in that post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 50 to 120 ° C, forming at least partially crosslinked polyurethane or stable gel.

2. Process for the coagulation of post-crosslinkable PUR dispersions according to claim 1, characterized in that post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 75 to 98 ° C, forming at least partially crosslinked polyurethane or stable gel.

3. Process for the coagulation of post-crosslinkable dispersions according to claim 1, characterized in that post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 50 to 120 ° C, forming at least partially cross-linked polyurethane or stable gel, and because the dispersions used have a) a content of blocked isocyanate groups (calculated as NCO = 42) of 0.1 to 7.5% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two groups primary amino and / or secondary (cyclo) aliphatically bound, the ratio of equivalents of blocked isocyanate groups of a) to amino groups b) to 1: 0.5 to 1: 1.5.

4. Process for the coagulation of post-crosslinkable PUR dispersions according to claim 1, characterized in that post-crosslinkable dispersions are precipitated by heat treatment at a temperature of 75 to 98 ° C, forming at least partially cross-linked polyurethane or stable gel, and because the dispersions used have a) a content of blocked isocyanate groups (calculated as NCO = 42) of 0.25 to 5% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two primary amino groups and / or attached (cyclo) aliphatically, the ratio of equivalents of blocked isocyanate groups' of a) to amino groups from b) to 1: 0.7 to 1: 1.2 increasing.

5. Process for the coagulation of post-crosslinkable PUR dispersions according to claim 1, characterized in that post-crosslinkable PUR dispersions are precipitated by heat treatment at a temperature of 75 to 98 ° C, forming at least partially cross-linked polyurethane or stable gel, and also because the dispersions used have a) a content of blocked isocyanate groups (calculated as NCO = 42) of 0.7 to 2% by weight, and b) a content of at least one polyamine and / or hydroxyamine with at least two groups primary amino and / or secondary (cyclo) aliphatically bound, the ratio of equivalents of blocked isocyanate groups of a) to amino groups from b) to 1: 0.9 to 1: 1.1.

6. Process for the coagulation of post-crosslinkable dispersions according to claim 1, characterized in that dispersions based on hydrophilic raw materials, especially hydrophilic polyols, form coagulates which are permeable to water vapor.

7. Post-crosslinkable coagulable polyurethane dispersions obtained according to claim 1, characterized in that they are reaction products, in the form of aqueous dispersions or emulsions, of at least one organic di- or polyisocyanate, or at least one polyhydroxy compound with a weight molecular up to 16,000, iü. ionic or potentially ionic hydrophilizing agents and / or nonionic hydrophilizing agents, iv. blocking agents for isocyanate groups and v. optionally mono-, di- or triamines of low molecular weight as chain-breaking components, • chain extenders or chain branders, and also vi. the crosslinking polyamines being contained in the dispersion, the components 3) being contained in amounts such that a stable dispersion is formed.

8. Post-crosslinkable coagulable polyurethane dispersions according to claim 6, characterized in that they are reaction products, in the form of aqueous dispersions or emulsions, of i. 9 to 30% by weight of at least one organic diisocyanate, ii. 40 to 85% by weight of at least one polyhydroxylic compound at least difunctional with a molecular weight of 350 to 4,000, iii. 4 to 22% by weight of ionic or potentially ionic hydrophilizing agents and / or nonionic hydrophilizing agents, iv. 0.5 to 5% by weight of blocking agents for isocyanate groups and v. 0 to 5% by weight of mono-, di- or triamines of low molecular weight as chain-breaking components, chain extenders or chain branchers, and further vi. the content of non-ionic hydrophilicizing agents 3.) to 3% by weight being contained in the dispersion of 1 to 6% by weight of crosslinking polyamines.

9. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that as an ionic hydrophilicizing agent 3.) they contain dimethylolpropionic acid and / or reaction products of 1 mole of diamine and 0.5 to 2 mole of acrylic acid .

10. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that as blocking agent 4.) contain butanone oxime, diisopropylamine and / or triazole.

11. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that as blocking agent 4.) they contain dimethylpyrazole.

12. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that as crosslinker 6.) they contain polyamines which furthermore act as a neutralizing agent of the acid groups of component 3.).

13. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that as crosslinker 6.) they contain isophoronediamine, TCD-diamine, Laromin C260, PACM 20 and / or diethylenetriamine.

14. Post-crosslinkable coagulable polyurethane dispersions obtained according to claims 1 and 7, characterized in that the component 2 is partially or totally constituted by hydrophilic polyols, thus obtaining coagulates permeable to water vapor.

15. Use of the coagulable dispersions obtained according to claim 1 for coating surfaces.

16. Coagulates obtained by the process according to claim 1.

17. Water vapor permeable coagulates obtained by the process according to claim 1.

18. Use of the dispersions obtained by the process according to claim 1 for the manufacture of flat articles, flat textile articles, coated substrates, sheets, gloves and protective covers.

19. Use of the coagulable dispersions according to claims 3 to 14 for the reinforcement of layers. ty < - ^ .- i? n-i.at.-p for coagulation HP aqueous dispersions of PUR containing reactive polyurethane or post-ret-tyi? 1? dispersed, products thus obtained and their use SUMMARY OF THE INVENTION The present invention relates to a process for the coagulation of PUR dispersions, to the cagulation products thus obtained and to the use of the coagulated PUR dispersions. Suitable reactive or post-crosslinkable PUR dispersions are suitable as PUR dispersions for the process according to the invention. The processes according to the invention comprise the production of films, the coating of the most diverse materials and the partial or total impregnation of layers, fabrics or other flat articles for reinforcement purposes.