MXPA97005224A - Comprehensive foam for polyurethane skin insuffled with water that has better abrasive resistance - Google Patents

Abstract

This invention relates to a process for preparing integral foams for the skin from a specific reaction mixture. The isocyanate of this reaction mixture consists of a stable liquid DIM-based prepolymer containing an allophanate-modified DIM and having an NCO content of 5 to 30%. This isocyanate consists of the reaction product of a DIM modified with allophanate and a polyether polyol. The integral skin foams prepared from these allophanate modified isocyanate prepolymers exhibit better properties and better taber abrasion resistance compared to conventional isocyanate prepolymers

Description

COMPREHENSIVE FOAM FOR POLYURETHANE SKIN INSUFFLED WITH WATER THAT HAS BETTER RESISTANCE ABRASION BACKGROUND OF THE INVENTION Field of the Invention This invention relates to integral foams for the skin having improved properties and to a process for the production of these foams. These foams are prepared from an isocyanate containing a liquid and stable DIM-based prepolymer containing an allophanate modified DIM. The liquid diphenylmethane diisocyanates and their use in the preparation of integral foams for the skin are generally known in the art. Various types of liquid diphenyl ethane diisocyanates include, for example, isocyanate prepolymers, isocyanates containing allophanate groups, isocyanates containing carbodiimide groups, isocyanates containing biuret groups, etc. These are described, for example, in US Pat. UU 3,644,457, 4,055,548, 4,115,429, 4,118,411, 4,160,080, 4,261,852, 4,490,300, 4,738,991 and 4,866,103 and in GB 994,890. Comprehensive skin foams prepared from polyurethane are also known in the art. These are described, for example, in U.S. Pat. 3,523,918, 3,726,952, 3,836,487, 3,925,527, 4,020,001, 4,024,090, 4,065,410, 4,305,991 and 5,166,183 and in CA 1,277,471. U.S. Pat. No. 3,644,457 describes liquid and stable isocyanates at room temperature derived from one mole of diphenylmethane diisocyanate and 0.1 to 0.3 moles of poly-1,2-propylene glycol ether. U.S. Pat. No. 4,055,548 discloses liquid isocyanate prepolymer compositions obtained by a polymethylene polyphenylisocyanate reaction containing from about 65 to 85 weight percent of methylene bis (phenyl) isocyanate with a polyoxyethylene glycol having a molecular weight of 200 to 600, in an equivalent ratio of 0.0185 to 0, 15: 1 Patents 4,115,429 and 4,118,411 disclose liquid and stable diphenylmethane diisocyanates in low temperature storage (up to -5 ° C) which are produced by reaction of diphenylmethane diisocyanates having a specified content of 2,4 isomer with propylene glycol or poly-1, 2-propylene ether glycol. U.S. Pat. No. 4,261,852 discloses liquid polyisocyanate compositions consisting of (a) the reaction product of 90 to 50% by weight of a reaction product of diphenylmethane diisocyanate and a polyoxypropylene diol or triol having a hydroxyl equivalent weight of 750 to 3000, said reaction product having an NCO content of from 8 to 26% by weight and (b) from about 10 to 50% by weight of a diphenylmethane diisocyanate containing from 30 to 65% by weight of diphenylmethane diisocyanate, the remainder being polymethylene polyphenyl polyisocyanate. U.S. Pat. No. 4,490,300 discloses liquid isocyanates stable at room temperature which are derived by reaction of diphenylmethane diisocyanate with an aliphatic diol having a pendant aromatic group, for example 2-methyl-2-phenyl-1,3-propanediol or phenyl-1,2. -ethanediol. U.S. Pat. No. 4,490,301 discloses liquid isocyanates stable at room temperature which are derived by reaction of diphenylmethane diisocyanate with trimethylolpropane monoallyl ether. U.S. Pat. 4,738,991 describes polyiso- organic cyanates characterized by allophanate linkages which are prepared by reaction of an organic polyisocyanate, including 2,4- and 4,4-methylenediphenyl diisocyanate, with polyhydric or monohydric alcohol, in the presence of an organometallic catalyst. The catalyst is then deactivated using a compound such as an inorganic acid, organic acid, organic chloroformate or an organic acid chloride. This reference also discloses that flexible foams can be prepared from these isocyanates containing allophanate groups. All the examples are related to isocyanates containing allophanate groups based on DIT and only one of these prepares a flexible foam of high elasticity. U.S. Pat. No. 4,866,103 discloses a polyisocyanate-containing composition for use in the production of elastomers in a MIR process. This polyisocyanate composition is the reaction product of an alcohol and / or thiol having an average functionality of about 1., 5 to about 4 and an average equivalent weight of at least 500, with at least 2 equivalents per equivalent of hydroxyl and / or thiol of an organic polyisocyanate, including the 4,4 and 2,4 isomers of diphenylmethane diisocyanate. The reaction described is carried out under conditions such that at least 20% of the initially formed urethane and / or thiourethane groups are converted into allophanate and / or thioalophonate groups. Another process for the preparation of allophanates containing isocyanates is described in British Patent 994,890, which relates to the reaction of urethane isocyanates with an excess of diisocyanate, either by heat alone or in the presence of a catalyst such as a metal carboxylate. , a metal chelate or a tertiary amine, until reducing the isocyanate content obtained theoretically when the complete reaction of the urethane groups is achieved. U.S. Pat. No. 4,160,080 describes a process for the production of aliphatic and / or cycloaliphatically bound isocyanate groups containing allophanate. In this described process, compounds containing urethane groups react with polyisocyanates having aliphatic and / or cycloaliphatic isocyanate groups in the presence of a strong acid. The process is generally carried out at a temperature of 90 ° C to 140 ° C for about 4 to 20 hours. Japanese Patent Application No. 1971-99176 describes a method of preparing a liquid diphenylmethane diisocyanate by reaction of diphenylmethane diisocyanate with an aliphatic monovalent alcohol. In U.S. Pat. 4,305,991 describes and prepares integral foams for the skin. These foams are prepared from a reaction mixture containing a polyisocyanate, where the isocyanate groups are attached aliphatically and / or cycloaliphatically. These polyisocyanates can contain adducts such as, for example, carbodiimide, allophanate, isocyanurate, uretdione, biuret, etc. The aliphatic isocyanates used to prepare these foams provide resistance to UV light and to decomposition by heat. U.S. Pat. No. 5,166,183 also describes integral foams for the skin. The polyisocyanate composition used therein has an NCO content of about 16 to 25% and consists of i) from 10 to 100 parts by weight of an isocyanate having an NCO content of about 16 to 22%, which is prepared by mixing methylenebis (phenyl isocyanate) and a methylenebis (isocyanate of phenyl) modified with carbodiimide groups, followed by reaction with a polyester diol to form a product. This product is then mixed with ii) from 0 to 90 parts by weight of a modified isocyanate having an NCO content of about 18 to 25%, which is prepared by reaction of methylenebis (phenyl isocyanate) with poly-1 , 2-propylene glycol ether. The presence of the carbodiimide-modified isocyanate in the prepolymer serves to reduce the freezing point. It is described that the integral foams for the skin of the patent 5,166,183 exhibit a better resistance to abrasion. The use of a polyester in the formation of the prepolymer contributes to this. The polyesters, however, add to the cost of the prepolymer and have a lower miscibility (solubility) with polyethers, so that the processing of the systems is difficult. Isocyanates modified with carbodiimide are also described as isocyanates suitable for the production of integral foams for the skin in US Pat. 5,342,856. These isocyanates are reacted with an isocyanate-reactive component and a solution of a zinc carboxylate in an aliphatic polyamine. These solutions of zinc carboxylates in aliphatic polyamines and water are essential for the preparation of integral foams for the skin. An object of the present invention was to develop a DIM-based prepolymer that would result in acceptable properties in integral skin foams inflated with water. Another object was to avoid the drawbacks of other integral foams for the skin, including, for example, the cost of the prepolymers prepared from polyesters and / or isocyanates modified with carbodiimide and the problems associated with stiffening when using prepolymers made with tripropylene glycol. COMPENDIUM OF THE INVENTION This invention relates to a process for the production of an integral foam for the skin and with the integral foam for skin produced by this process. This process consists in filling a closed mold with a reaction mixture consisting of A) a stable liquid DIM-based prepolymer containing an allophanate-modified DIM with B) an isocyanate-reactive composition, C) an insufflating agent consisting of water and D) at least one catalyst. The prepolymers A) based on stable liquid DIM have an NCO content of 5 to 30%, preferably from 15 to 29% and, more preferably, from 18 to 27% and contain an allophanate modified DIM, wherein the prepolymer consists of the reaction product of: 1) an allophanate-modified DIM prepared by reaction of: i) an aliphatic alcohol or an aromatic alcohol, wherein said alcohol contains less than 16, preferably less than 9 carbon atoms, with ii) diphenylmethane diisocyanate containing from about 0 to about 60% by weight 2,4 '-diphenylmethane diisocyanate, less than 6% by weight of 2,2'-diphenylmethane diisocyanate and the remainder being 4,4'-diphenylmethane diisocyanate and 2) a polyether polyol containing from 2 to 3 hydroxyl groups and having a molecular weight of about 76 to 10,000, preferably approximately 150 to approximately 6,000. Suitable isocyanate-reactive compositions consist of: 1) from 80 to 99% by weight, preferably from 85 to 97%, based on 100% by weight of components B) l) and B) 2), of one or more organic compounds of high molecular weight containing at least 2, preferably 2 to 3, isocyanate-reactive groups and having a molecular weight of from about 2,000 to about 10,000, preferably from about 4,000 to about 6,000, and 2) from 1 to 20%, preferably from 3 to 10%, based on 100% by weight of components B) l) and B) 2), of one or more organic compounds of low weight molecular units containing at least 2, preferably from 2 to 3, isocyanate-reactive groups and having a molecular weight of from 32 to 200, preferably from 60 to 150. The reaction mixture also contains C) an insufflating agent consisting of water and D ) at least one catalyst. This reaction mixture, inside the closed mold, is allowed to fully react to form the integral foam for the skin and the integral foam for the resulting skin is removed from the mold. This invention also relates to integral foams for the skin produced by the above process. DETAILED DESCRIPTION OF THE INVENTION Prepolymers based on stable liquid DIM suitable having an NCO content of about 5 to 30%, preferably 15 to 29% and, more preferably, 18 to 27% and containing an allophanate-modified DIM. These stable liquid DIM-based prepolymers consist of the reaction product of: 1) an allophanate modified DIM and 2) a polyether polyol. These isocyanate prepolymers are known and are described in, for example, US Pat. 5,319,053, the description of which is hereby incorporated by reference. The 1) allophanate-modified DIM suitable for use in the preparation of the stable liquid DIM-based prepolymer consists of the reaction product of (i) an aliphatic alcohol or an aromatic alcohol, wherein said alcohol contains less than 16, preferably less than 9. carbon atoms and (ii) diphenylmethane diisocyanate, consisting of from about 0 to 60% by weight of 2,4'-diphenylmethane diisocyanate, less than 6% by weight of 2,2'-diphenylmethane diisocyanate and being the residue 4,4'-diphenylmethane diisocyanate. Some compounds suitable for use as aliphatic alcohols (i) include, for example, isomeric butanols, isomeric propanols, isomeric pentanols, isomeric hexanols, cyclohexanol, 2-methoxyethanol, 2-bromoethanol, etc. Suitable aromatic alcohols for use in the preparation of the allophanate-modified prepolymer include, for example, phenol, l-naphthol, m-cresol and p-bromophenol. Preferred aliphatic alcohols are 1-butanol, 1-pentanol and 1-propanol. Preferred aromatic alcohols are phenol and m-cresol. The diphenylmethane diisocyanate preferably consists of about 1 to about 3% of the 2,4'-isomer of DIM, 0 to 1% of the 2,2'-isomer of DIM and 96-99% of the 4,4-isomer. 'of DIM. It is preferred that 1) DIM modified with allophanate is also a stable liquid and has an NCO content of about 15 to 29%. As polyether polyols 2) suitable for reaction with 1) the allophanate-modified DIM to form the A) currently required stable liquid DIM prepolymers containing an allophanate-modified DIM include those polyether polyols containing from about 2 to 3 hydroxyl groups and having molecular weights of from about 76 to about 10,000, preferably from about 150 to about 6,000. These polyether polyols can be obtained in a known manner by reacting the starting compounds containing hydrogen atoms reactive with alkylene oxides, such as ethylene oxide., propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin or mixtures of these alkylene oxides. Suitable starting compounds containing reactive hydrogen atoms include polyhydric alcohols, such as, for example, ethylene glycol, propylene glycol- (1, 2) and - (1,3), butylene glycol- (1, 4) and 1 ( 1,3), hexanediol- (1, 6), octanediol- (1, 8), neopentyl glycol, cyclohexanedimethanol (1,4-bishydroxymethylcyclohexane), 2-methyl-1,3-propanediol, 2,2,4-trimethyl- 1, 3-pentanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycol, glycerin and trimethylolpropane and, in addition, water, methanol, ethanol, 1,2,6-hexanetriol, 1,2-butanetriol, trimethylolethane, pentaerythritol, mannitol, sorbitol, methyl glycoside, sucrose, phenol, isononylphenol, resorcinol, hydroquinone, 1,1,1- or 1,1,1-tris (hydroxyphenyl) ethane. They are preferred polyether polyols for the preparation of the DIM-based prepolymere. stable liquid containing allophanate groups those compounds having a functionality of 2 or 3, molecular weights of about 1,500 to about 6,000 and are prepared by alkoxylation of a suitable initiator with ethylene oxide, propylene oxide or mixtures thereof. The above-described liquid DIM-based prepolymer containing allophanate groups reacts with an isocyanate-reactive composition to form an integral foam for the skin. These isocyanate-reactive compositions consist of B) 1) one or more organic compounds containing at least 2, preferably 2 to 3, isocyanate-reactive groups and having a molecular weight of from about 2,000 to about 10,000, preferably from about 4,000 to 6,000, and B) 2) one or more organic compounds containing at least two, preferably 2 to 3, isocyanate-reactive groups and having a molecular weight of from about 32 to about 200, preferably from about 60 to about 150. As suitable for use as organic compounds containing at least 2 isocyanate-reactive groups and having molecular weights of from about 2,000 to about 10,000 are included, for example, polyethers, polyesters, polymeric polyols, PHD polyols (a dispersion of a polyurea and / or polyhydrazodicarbonamide in a relatively high molecular weight organic compound containing the minus two hydroxyl groups), polyether-ether, polyacetals, polycarbonates and amine-terminated polyethers containing at least 2 isocyanate-reactive groups of the type known for the production of polyurethanes. Suitable polyethers of high weight Molecules for use according to the invention are known and can be obtained, for example, by polymerization of tetrahydrofuran or epoxides such as, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide or epichlorohydrin, in the presence of catalysts suitable, such as, for example, BF3 or KOH, or by chemical addition of these epoxides, preferably ethylene oxide and propylene oxide, in admixture or successively, to components containing reactive hydrogen atoms, such as water, alcohols or amines . Examples of suitable alcohols and amines include the low molecular weight chain extenders indicated below, propylene glycol, glycerin, ethylene glycol, triethanolamine, water, trimethylolpropane, bisphenol A, sucrose, aniline, ammonia, ethanolamine and ethylenediamine. It is preferred to use polyethers having a functionality of 2 or 3, molecular weights of from about 1,500 to about 6,000 and prepared by alkoxylation of a suitable initiator with ethylene oxide, propylene oxide or mixtures thereof. Suitable low molecular weight chain extenders suitable for use in the polyol mixture include organic compounds containing hydroxyl groups, amino groups and sulfhydryl groups, having molecular weights of about 32 to about 200. Suitable compounds include, for example, , diols, triols, diamines, triamines, dithiols, tritiols and their mixtures. Chain extenders containing hydroxyl groups are preferred. Examples of suitable hydroxyl-containing compounds include glycols, such as, for example, ethylene glycol, propylene glycol, 1,2- and 1,3-propanediol, 1,3-, 1,4- and 2,3-butanediol. , 1,6-hexanediol, dipropylene glycol, tripropylene glycol, diethylene glycol (ie, DEG), triethylene glycol (ie, TEG), tetraethylene glycol, tetrapropylene glycol, heptapropylene glycol, 2-methyl-1,3-propanediol, 1,10-decanediol, neopentyl glycol and 2,2, 4-trimethylpentane-1,3-diol, etc. Preferred chain extenders include ethylene glycol, 1,4-butan diol and diethylene glycol. The present invention also requires water as an insufflating agent. It is also possible to use water together with other insufflating agents, such as, for example, pentane, acetone, partially or fully fluorinated hydrocarbons and methylene chloride. It is preferred to use water as the sole insufflating agent. When water is used as the sole insufflating agent, it is typically used in the present invention in amounts of between about 0.05 and 1% by weight and, preferably, between about 0.35 and 0.7% by weight, based on 100% by weight of the polyol side (side B) of the formulation. Of course, as described above, water can be used in combination with other insufflating agents. The above ranges for water as the sole insufflating agent are exceeded when mixtures of water and another blowing agent are used in the present invention. Mixtures of insufflating agents of this type need to be present in typical amounts of a conventional process to produce an integral foam for the skin. It is also required that the catalysts be present in the reaction mixture according to the present invention. Suitable catalysts include, for example, tertiary amine catalysts and organometallic catalysts. Some examples of organometallic catalysts suitable include, for example, organometallic compounds of tin, lead, iron, bismuth, mercury, etc. Preferred organotin catalysts include compounds such as, for example, tin acetate, tin octoate, tin ethylhexanoate, tin oleate, tin laurate, dimethyltin dilaurate, dibutyltin oxide, dibutyltin dichloride, dimethyltin dichloride, dibutyltin diacetate, diethyltin diacetate, dimethyltin diacetate, dibutyltin dilaurate, diethyltin dilaurate, dimethyltin dilaurate, dibutyltin maleate, dimethyltin maleate, dioctyltin diacetate, dioctyltin dilaurate, ddii (2-ethylhexyl) tin oxide, , etc. Especially preferred are heat activated or delayed-action tin catalysts, such as, for example, dibutyltin dimercaptide, dibutyltin diisooctylmercactacetate, dimethyltin dimercaptide, dibutyltin dilaurylmercaptide, dimethyltin dilaurylmercaptide, dimethyltin diisooctylmercaptoacetate, bis (isooctylmercaptoacetate) di (n-butyl) tin and di (isooctyl) tin bis (isooctylmercaptoacetate), all of which are commercially available from Witco Chemical Corp. The use of a slow acting catalyst such as an iron pentanedione or a bismuth carboxylate, as described in U.S. Pat. 4,611,044, incorporated herein by reference, is also possible. Heat-activated catalysts suitable for the present invention are amine salts. These catalysts include aliphatic and aromatic tertiary amines. Suitable heat-activated amine salts include compounds such as, for example, DABCO 8154, from Air Products, an acid blocked triethylene diamine formic, and other delayed action catalysts, such as DABCO WT, also from Air Products, and Polycat SA-1 and Polycat SA-102, which are both blocked versions with 1,8-drazabicyclo [5.4.0] undeceno- 7 (ie, Polycat DBU) and marketed by Air Products. Trialkylamines and heterocyclic amines are also suitable for the present invention. Suitable compounds include, for example, trimethylamine, triethylamine, tripropylamine, tributylamine, dimethylcyclohexylamine, dibutylcyclohexyl amine, dimethylethanolamine, triethanolamine, diethylethanolamine, ethyldiethanolamine, dimethyl isopropanolamine, triisopropanolamine, triethylenediamine, tetramethyl-1,3-butanediamine, N, N , N ', N' -tetramethylethylenediamine, N, N, ', N' -tetramethylhexanediamine-1,6,6, N, N, N 1, '-pentamethyldiethylenetriamine, bis (2-methylaminoethoxy) methane, N, N, N '-trimethyl-N' - (2-hydroxyethylethyldiamine), N, Nd? Methyl-N ', N' - (2-hydroxyethyl) -ethylenediamine, tetramethylguanidine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N- ethylmorpholine, 1/4-dimethylpiperidine, 1,2-trimethylpiperidine, N- (2-methylamino-ethyl) morpholine, l-methyl-4- (2-dimethylamino) piperidine, 1,4-diazabicyclo- [2.2.2] Octane, 2-methy1-1, 4-diazabicyclo [2.2.2] octanoquinuclidine, 1,5-diazabicyclo [5.4.0] -5-undecene and 1,5-diazabicyclo [4.3.0] -5-nonane. organ O-metals are normally used in amounts ranging from about 0.005 to about 0.5% by weight, preferably about 0.02 and 0.4% by weight, based on 100% by weight of the polyol side (side B) of the formulation. The tertiary amine catalysts, or their salts, are advantageously used in amounts ranging from about 0.05 to about 2% by weight, preferably about 0.1 and about 0.5% by weight, in 100% by weight base of the polyol side (side B) of the formulation. It is preferred that the total amount of catalysts be such that they constitute less than 2% by weight, preferably less than 1% by weight of 100% by weight of the polyol side (side B) of the formulation. It is also possible to be able to include various additives and / or auxiliary agents in the formulation. Some examples of suitable additives include surfactant additives such as emulsifiers and foam stabilizers. Examples of these include N-stearyl-N1, N'-bishydroxyethylurea, oleyl polyoxyethyleneamide, stearilic diethanolamide, isostearyl diethanolamide, polyoxyethylene glycol monooleate, an ester of pentaerythritol / adipic acid / oleic acid, a hydroxyethylimidazole derivative of oleic acid, N-stearylpropylenediamine and the sodium salts of sulfonates of castor oil or fatty acids. Alkali metal or ammonium salts of sulfonic acid, such as dodecylbenzenesulfonic acid or dinaphthylmethanesulfonic acid and also fatty acids can be used as surfactant additives. Suitable foam stabilizers include water-soluble polyether siloxanes. The structure of these compounds is generally such that a copolymer of ethylene oxide and propylene oxide is attached to a polydimethylsiloxane radical. Said foam stabilizers are described in US Pat. 2,764,565. In addition to surfactants, other additives that can be used in the molding compositions of the present invention include agents for release of known internal molds, pigments, cell regulators, flame retardants, plasticizers, dyes, fillers and reinforcing agents, such as glass in the form of fibers or flakes or carbon fibers. The compositions according to the present invention can be molded using conventional processing techniques at isocyanate rates ranging between about 95 and 105 (preferably between 98 and 103). The term "Isocyanate Index" (which is also commonly referred to as the NCO index), is defined here as the isocyanate equivalents, divided by the total equivalents of materials containing isocyanate-reactive hydrogen, multiplied by 100. As is used herein, the phrase "polyol side" or "side B" refers to the mixture containing the isocyanate-reactive compositions B) 1) and B) 2), the blowing agent C), the catalyst D) and any other additive or auxiliary agent that were mixed with these prior to the reaction with the isocyanate A). The following examples further illustrate the details of the process of this invention. The invention, set forth in the foregoing description, is not limited in spirit or scope by these examples. Those skilled in the art will readily understand that known variations of the conditions of the following procedures can be used. Unless stated otherwise, all temperatures are in degrees Celsius and all parts are parts by weight. EXAMPLES The following materials were used in the operative examples: Isocyanate A: An allophanate-modified isocyanate prepolymer having an NCO content of 23.4%, prepared by reaction of 100 parts of DIM having an isomer distribution of 98% of the 4,4 'isomer and 2% of the 2,4' isomer, with 3,4 parts (0,57 equivalents) of 1-butanol, to obtain an intermediate that reacted then with 8.6 parts of tripropi lenglicol. Isocyanate B: An isocyanate prepolymer having an NCO content of 23%, prepared by reaction of 100 parts of pure monomeric DIM (containing 98% of the 4,4 'isomer and 2% of the 2,4' isomer) with 15.9 parts of tripropylene glycol. Polyol A: A polyoxyalkylenetriol initiated with glycerin having an OH number of 28 and prepared from 87% propylene oxide and 13% ethylene oxide. EG: Ethylene glycol. Catalyst A: A dialkyl tin dimercaptide catalyst, marketed by Witco Corporation as UL-1. Catalyst B: A catalyst containing tertiary amine, marketed by Air Products, Inc. as Dabco 33LV. Catalyst C: A catalyst containing tin, marketed by Tylo Industries as Topcat 290. The following side B was used in the examples: Polyol A 100 parts EG 4, 79 parts Catalyst A 0, 053 parts Catalyst B 0.63 parts Catalyst C 0.265 parts Water 0.45 parts In the examples, the following procedure was used to prepare the foams. In each case, a Kymofoam Type KF-IS-202 foam machine was used under the following conditions: a) the temperature of both side A and side B was about 30 ° C, b) the mold temperature was about 50 ° C, c) the flow rate was about 60 g / sec and d) the isocyanate index was 100. Molded parts were prepared by pouring the liquid reaction mixture into a 20.3 cm x 20 aluminum plate mold, 3 cm x 2.54 cm (8 inches by 8 inches by 1 inch) and demolding in approximately 3 and a half minutes. The parts were studied in terms of density, Shore A hardness, tensile strength, elongation, C die tear, block tear and abrasion resistance, with the results shown in Table 1. The densities given in the Table 1 were obtained by measuring the mass (in grams) of the molded part and dividing the mass by the volume of the mold in cubic centimeters. Example A (comparative): A polyurethane foam was prepared by reaction of Isocyanate B with the B side described above, at an NCO index of 100. Example B (comparative): A polyurethane foam was prepared by reaction of Isocyanate B with side B described above, at an NCO index of 100. Example 1: A polyurethane foam was prepared by reaction of Isocyanate A with the B side described above, to a NCO index of 100. Example 2: A polyurethane foam was prepared by reaction of Isocyanate A with the B side described above, at an NCO index of 100. Example 3: A polyurethane foam was prepared by reaction of Isocyanate A with side B described above, at an NCO index of 100. Physical properties were determined for each foam using the following ASTM test methods: Shore A hardness: ASTM D-2240 Tensile strength: ASTM D-412 Elongation: ASTM D-412 Die Cutting C: ASTM D-624 and D-3489 Block Tearing: ASTM D-3574F Taber Abrasion Resistance: ASTM D-3489 Although the invention has been described in detail in the foregoing for purposes of illustration, it is to be understood that such detail has only those purposes and that those skilled in the art can make variations therein without departing from the spirit and scope of the invention, except in what may be limited by the claims.

Claims (1)

CLAIMS 1. A process for the production of an integral foam for the skin consisting of filling a closed mold with a reaction mixture, wherein said reaction mixture consists of: A) A prepolymer based on stable liquid DIM having an NCO content from 5 to 30% and containing an allophanate modified DIM, wherein said prepolymer consists of the reaction product of: 1) an allophanate-modified DIM prepared by reacting: i) an aliphatic alcohol or an aromatic alcohol, wherein said alcohol contains less than 16 carbon atoms, with ii) diphenylmethane diisocyanate containing approximately 0 to 60% by weight of 2,4'-di-n-methane diisocyanate, less than 6% by weight of diisocyanate of 2, 2 'diphenylmethane and the remainder being 4,4'-diphenylmethane diisocyanate and 2) a polyether polyol containing 2 to 3 hydroxyl groups and having a molecular weight of about 76 to 10,000; B) an isocyanate-reactive composition consisting of: 1) from 80 to 99% by weight, based on 100% by weight of components B) 1) and B) 2), of one or more organic compounds of high molecular weight containing at least 2 isocyanate-reactive groups and that they have a molecular weight of approximately 2,000 to 10,000 and 2) of 1 to 20%, based on 100% by weight of components B) l) and B) 2), of one or more organic compounds of low molecular weight containing at least 2 isocyanate-reactive groups and having a molecular weight of from about 32 to about 200; C) an insufflating agent consisting of water, and D) at least one catalyst, allowing said reaction mixture to fully react and separating the resulting foamed part from the mold. The method of Claim 1, wherein said stable liquid DIM-based prepolymer has an NCO content of about 15 to 29% by weight and consists of the reaction product of 1) an allophanate-modified DIM prepared by reaction of: i) an aliphatic alcohol or an aromatic alcohol containing less than 9 carbon atoms with ii) diphenylmethane diisocyanate consisting of about 1 to 3% by weight of the 2,4'-isomer, about 0 to 1 % by weight of the 2,2"isomer and approximately 96 to 99% by weight of the 4,4 'isomer and 2) a polyether polyol having a molecular weight of from about 150 to about 6,000. of Claim 2, where said aliphatic alcohol l) i) is selected from the group consisting of 1-butanol, 1-pentanol and 1-propanol. 4. The method of Claim 2, wherein said aromatic alcohol l) i) is selected from the group consisting of phenol and m-cresol. The method of Claim 1, wherein B) said isocyanate-reactive composition consists of: 1) One or more high molecular weight organic compounds containing from 2 to 3 isocyanate-reactive groups and have a molecular weight of about 4,000 to 6,000 and 2) one or more low molecular weight organic compounds containing 2 to 3 isocyanate-reactive groups and have a molecular weight of about 60 to about 150. The method of Claim 2, wherein the NCO content of said stable liquid DIM-based prepolymer is from 18 to 27% by weight. 7. An integral foam for the skin produced by the method of Claim

1.