Abstract: This invention is a liquid polyisocyanate prepolymer comprising the reaction product of an organic polyisocyanate blend and a polyoxyalkylene polyol, where polyisocyanate blend isA) a diphenylmethane diisocyanate comprising from 50 weight percent to 95 weight percent 4,4'-diphenylmethane diisocyanate, from 5 weight percent to 50 weight percent 2,4'-diphenylmethane diisocyanate, and less than 10 weight percent 2,2'-diphenylmethane diisocyanate, said weight percentages based on the total weight of the ingredients in A);B) a polymethylene polyphenyl polyisocyanate comprising from 30 weight percent to 70 weight percent diphenylmethane diisocyanate, the remainder comprising polymethylene polyphenyl polyisocyanates having functionalities greater than two, said weight percentages based on the total weight of the ingredients in B);C) and optionally a uretonimine-carbodiimide modified diisocyanate comprising from 10 weight percent to 35 weight percent uretonimine-carbodiimide species, the remainder comprising essentia

Abstract: Process for making flexible polyurethane foams using MDI and TDI and a polyol composition comprising dispersed particulate material.

Abstract: The present invention relates to a process for preparing a flexible polyurethane foam from the reaction of a polyisocyanate composition prepared from the reaction of an excess of organic polyisocyanate and a polyether polyol having a high ethylene oxide content and an isocyanate reactive composition comprising a chain extending agent and a combination of a polyether polyol having a high ethylene oxide content and a random copolymer having a high ethylene oxide content, and the product prepared therefrom.

Abstract: Process for preparing a flexible polyurethane foam by reacting a polyisocyanate and two different polyols under foam forming conditions so as to prepare a rigid foam, by crushing the rigid foam so obtained and by subjecting the flexible foam so obtained to a heat treatment. Flexible foams are obtained which do not show a major glass transition temperature between -100.degree. C. and +25.degree. C.

Abstract: Process for preparing a flexible polyurethane foam by reacting a polyisocyanate and two different polyols under foam forming conditions so as to prepare a rigid foam and by crushing the rigid foam so obtained in a direction perpendicular to the direction of rise of the foam. Flexible foams are obtained which do not show a major glass transition temperature between -100.degree. C. and +25.degree. C. and which have an anisotropy of 1.80 to 4.00.

Abstract: Propylene oxide is added to an active hydrogen compound in the presence of an alkali metal hydroxide catalyst in an amount of from 0.05 to 0.5 mole per mole of the active hydrogen compound at a reaction temperature of from 60 to 98.degree. C. at a reaction pressure less than or equal to 4 kg/cm.sup.2 to prepare a polyoxyalkylene polyol which has a hydroxyl value of from 10 to 35 mg KOH/g, a monool content less than or equal to 15 mol %, a Head-to-Tail bond selectivity greater than or equal to 96 percent, and low viscosity. A polymer polyol is prepared by polymerizing an ethylenically unsaturated monomer in the polyoxyalkylene polyol. A flexible polyurethane foam is prepared by reacting the polyoxyalkylene polyol or the polymer polyol with an organic polyisocyanate compound in the presence of a foaming agent, a catalyst, a surfactant, a crosslinking agent and other additives.

Abstract: There is now provided a method of recycling toluenediisocyanate residue resulting from the production of toluenediisocyanate by the reaction of toluenediamine by phosgenation in the presence of a solvent. In accordance with the teachings of the present invention, the toluenediisocyanate residue is treated at reflux with an alkanolamine to obtain an intermediary product which is distilled thereby giving rise to various products including but not limited to at least one component selected from toluenediamine, oxazolidone and hydroxyethylimidiazolidone. Preferably the alkanolamine employed is a monoethanolamine.

Abstract: Process for preparing a flexible foam by reacting a polyisocyanate composition having an NCO value of 11-24% by weight with an isocyanate-reactive compound having a number average molecular weight of 1000-12000 using water as blowing agent.

Abstract: This invention relates to molded articles comprising micro cellular polyurethane foams, preferably integral skin foams. These exhibit improved properties and are particularly suitable for soling systems in footwear. The present invention also relates to a process for the production of these molded articles. These molded articles comprise the reaction product of (A) an isocyanate comprising a stable, liquid MDI based prepolymer containing an allophanate-modified MDI, with (B) an isocyanate reactive component, in the presence of (C) at least one blowing agent.

Abstract: The present invention is directed to a low density flexible polyurethane foam and the process of making the same from a polyisocyanate composition and an isocyanate reactive composition wherein the polyisocyanate composition comprises a semi-prepolymer which is the reaction product of an excess of a base isocyanate formulation with a polyoxyethylene polyol, said base isocyanate formulation comprising a mixture of diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, said diphenylmethane diisocyanate comprising, inter alia, 2, 4'-MDI in prescribed amounts, whereby the functionality of the base isocyanate formulation ranges from 2.07 to 2.12 and said isocyanate reactive composition comprises water, a second polyoxyethylene polyol, a cross-linker and catalyst.

Abstract: This invention relates to flexible foams and flexible molded foams prepared from an isocyanate component comprising an allophanate-modified diphenylmethane diisocyanate. The present invention also relates to processes for the production of these flexible foams and flexible molded foams.

Abstract: The invention pertains to flame retardant flexible polyurethane foams prepared by reacting a polyether polyol and an organic isocyanate in the presence of a blowing agent and incorporating melamine and an effective amount of another flame retardant. The organic isocyanate comprises carbodiimide-uretonimine-modified diphenylmehtane diisocyanate and toluene diisocyanate. The polyurethane foams exceed conventional flame retardancy standards and exhibit flame spread index values of less than 25 as measured under flame test procedure ASTM D3675-90.

Abstract: A method for the preparation of flexible polyurethane foams by reacting a polyisocyanate containing at least 85% by weight of 4,4'-diphenylmethane diisocyanate or a liquid variant thereof with a polyol composition comprising at least one poly(oxyethylene-oxyalkylene) polyol having an average nominal hydroxyl functionality of from 2 to 6, a number average hydroxyl equivalent weight of from 1000 to 3000, and an average oxyethylene content of from 50 to 85% by weight and with water in the presence of a catalytically effective amount of an alkali or alkaline earth metal carboxylate salt.

Abstract: This invention relates to polyurethane elastomers produced by the reaction of polyisocyanates with polyesterpolyether polyols (diester-polyether diols) using the reaction injection molding process (RIM).

Abstract: An open-celled polyurethane foam is provided having a density of 1.5 to 5.0 pcf, a G value of 30 to 80 over a static load range of 1.0 to 2.0 psi based on a 2.0 inch thickness and a 24 inch drop height and, an airflow in the range of 0.05 to 0.5 scfm, 25% as compressive strength of 4.

Abstract: A pressure sensitive adhesive consisting of a polyurethane foam is used for adhering decorative parts to automobiles and other vehicles. The adhesive is characterized by high tensile strength and elongation, excellent peel strength and good thermal and mechanical stress tolerance.

Abstract: A flexible high-resilience polyurethane foam which has improved impact resilience and compression set, excellent effect on the reduction of transmissibility at 6 Hz and also improved mechanical strengths even under a reduced amount of a catalyst and is prepared by using, as an organic polyisocyanate composition, a mixture having a specified ratio of tolylene diisocyanate to polymethylenepolyphenyl isocyanate having a specific benzenoid composition or by using an isocyanate terminated prepolymer obtained by reacting the mixture with polyoxyalkylene polyol which has specific structure and is used for modification, and by using polyalkylene polyol which satisfies specific conditions in a hydroxyl value, monool content, and head-to-tail coupling selectivity; and a preparation process of the flexible high resilience polyurethane foam.

Abstract: The present invention relates to water-blown integral skin polyurethane foam compositions, molded polyurethane articles, a process of preparing said articles, and an isocyanate composition for use therein. In particular, the invention relates to water-blown integral skin molded polyurethane articles having particularly advantageous physical properties, and compositions useful for producing such articles. In particular, the invention provides a polyurethane composition which has an isocyanate component (a) an isocyanate reactive component (b), a blowing agent comprising water (c), a polyether (d) selected from the group consisting of polytetrahydrofuran and polyethylene glycol having a number average molecular weight of from 200 to 2000 and optionally, one or more additives (e) from the group consisting of catalysts, chain extenders, oxo alcohols, and mixtures thereof.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 30 to 80 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw of a mixture of uretonimine with from 10 to 70 parts by weight of a polyol (b) having a number average molecular weight of between 1000 and 10,000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of less than 20 and a viscosity of from 200 to 1000 cPs.

Abstract: The present invention relates to water-blown integral skin polyurethane foam compositions, molded polyurethane articles, a process of preparing said articles, and an isocyanate composition for use therein. In particular, the invention relates to water-blown integral skin molded polyurethane articles having particularly advantageous physical properties, and compositions useful for producing such articles. In particular, the invention provides a polyurethane composition which has an isocyanate component (a) an isocyanate reactive component (b), a blowing agent comprising water (c), a polyether (d) selected from the group consisting of polytetrahydrofuran and polyethylene glycol having a number average molecular weight of from 200 to 2000 and optionally, one or more additives (e) from the group consisting of catalysts, chain extenders, oxo alcohols, and mixtures thereof.

Abstract: A method for the preparation of flexible polymeric foam by reacting a polyisocyanate component with an isocyanate-reactive component comprising at least 50% by weight of water, the polyisocyanate component comprising at least two polyisocyanate compositions, one of them being a low NCO isocyanate terminated prepolymer and the second being a high NCO polyisocyanate.

Abstract: Process for making a flexible foam by reacting a polyisocyanate composition having an NCO value of 10-25% by weight and 30-150 parts by weight, per 100 parts by weight of polyisocyanate composition, of a polyol composition comprising water at an isocyanate-index of 40-100.

Abstract: Process for making a flexible foam by reacting a polyisocyanate composition having an NCO value of 10-25% by weight and 30-150 parts by weight, per 100 parts by weight of polyisocyanate composition, of a polyol composition comprising water at an isocyanate-index of 40-100.

Abstract: Polyether polyol comprising as alkylene oxide units ethylene oxide and propylene oxide units, said polyol having a nominal average hydroxyl functionality of 2-6, an hydroxyl value of 16-45 mg KOH/g, a primary hydroxyl content of at least 50% calculated on the total amount of hydroxyl groups and an amount of ethylene oxide units, calculated on the weight of the alkylene oxide units in the polyol, of 21-49% by weight these polyols are useful for making flexible foam.

Abstract: Polyether polyol comprising as alkylene oxide units ethylene oxide and propylene oxide units, said polyol having a nominal average hydroxyl functionality of 2-6, an hydroxyl value of 16-45 mg KOH/g, a primary hydroxyl content of at least 50% calculated on the total amount of hydroxyl groups and an amount of ethylene oxide units, calculated on the weight of the alkylene oxide units in the polyol, of 21-49% by weight. These polyols are useful for making flexible foam.

Abstract: A RIM process utilizing a reaction product of an MDI containing from 6 to 50% by weight of the 2,4'-isomer and a polypropylene glycol as the isocyanate reactant results in a molded product having excellent low temperature impact properties.

Abstract: This invention relates to a novel polyisocyanate based on polymethylene poly(phenylisocyanate), to a process for the production of a polyurethane backing on a substrate using this novel polyisocyanate to produce the polyurethane backing, and to the polyurethane backed substrate produced by this process. In particular, this novel polyisocyanate has a functionality of less than about 2.4, an isocyanate group content of 25 to 30%, and a urethane content of from about 2 to 6%, and comprises comprising polymethylene poly(phenylisocyanate), from about 5 to 25% of 4,4'-methylene bis(phenyloisocyanate), and from about 20 to 50% of 2,2'- and 2,4'-methylene bis(phenyl-isocyanate). This polyisocyanate can be reacted with a polyol mixture to produce the polyurethane backing on a substrate.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 40 to 90 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw 3-ring oligomers of polymethylene polyphenyl polyisocyanate;(iv) 1 to 20 pbw of n-ring oligomers of polymethylene polyphenyl polyisocyanate (n being greater than 3); and(v) 1 to 10 pbw of a mixture of uretonimine with from 5 to 50 parts by weight of a propoxylated propylene glycol (b) having a number average molecular weight of between 2000 and 6000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of from 20 to 30 and a viscosity of from 50 to 500 cPs.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 40 to 90 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw 3-ring oligomers of polymethylenepolyphenyl polyisocyanate;(iv) 1 to 20 pbw of n-ring oligomers ofpolymethylene polyphenyl polyisocyanate (n being greater than 3); and(v) 1 to 10 pbw of a mixture of uretonimine with from 5 to 50 parts by weight of a propoxylated propylene glycol (b) having a number average molecular weight of between 2000 and 6000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of from 20 to 30 and a viscosity of from 50 to 500 cPs.

Abstract: Method for preparation of fluorochlorohydrocarbon-free (FCHC-free) low-density polyurethane soft-foam materials and soft-elastic polyurethane soft-foam materials as well as polyisocyanate mixtures modified with urethane groups, and based on diphenylmethane-diisocyanate, which are applicable thereto.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 30 to 80 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw of a mixture of uretoniminewith from 10 to 70 parts by weight of a polyol (b) having a number average molecular weight of between 1000 and 10,000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of less than 20 and a viscosity of from 200 to 1000 cPs.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 30 to 80 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw of a mixture of uretonimine with from 10 to 70 parts by weight of a polyol (b) having a number average molecular weight of between 1000 and 10,000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of less than 20 and a viscosity of from 200 to 1000 cPs.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 40 to 90 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw 3-ring oligomers of polymethylene polyphenyl polyisocyanate;(iv) 1 to 20 pbw of n-ring oligomers of polymethylene polyphenyl polyisocyanate (n being greater than 3); and(v) 1 to 10 pbw of a mixture of uretonimine with from 5 to 50 parts by weight of a propoxylated propylene glycol (b) having a number average molecular weight of between 2000 and 6000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of from 20 to 30 and a viscosity of from 50 to 500 cPs.

Abstract: The invention provides a process for the preparation of a cellular polymeric product which comprises reaction of a polyisocyanate composition with an isocyanate-reactive composition having a functionality of at least 2, in the presence of a blowing agent and in the presence of an inert, organic liquid which is substantially insoluble in the reaction mixture and which is present as the disperse phase of an emulsion or a microemulsion, characterized in that the polyisocyanate composition comprises polymethylene polyphenylene polyisocyanate having a functionality of at least 2.5 and a urethane-modified, isocyanate-ended prepolymer, wherein the isocyanate functionality of the polyisocyanate composition is at least 2.3 and wherein the concentration of urethane linkages in the polyisocyanate composition is in the range from 1 millimole to 150 millimoles per 100 grams thereof.

Abstract: Process for making a flexible foam by reacting a polyisocyanate composition having an NCO value of 10-25% by weight and 30-150 parts by weight, per 100 parts by weight of polyisocyanate composition, of a polyol composition comprising water at an isocyanate-index of 40-100.

Abstract: Disclosed as a particular isocyanate prepolymer composition particularly suitable for use in polyurethane compositions having particular applicability for producing microcellular molded polyurethane articles particularly suitable for use as sealing devices. In particular, the isocyanate prepolymer composition is the result of reacting an isocyanate blend (a) having(i) 0 to 10 pbw 2,4'-diphenylmethane diisocyanate;(ii) 40 to 90 pbw 4,4'-diphenylmethane diisocyanate;(iii) 1 to 10 pbw 3-ring oligomers of polymethylene polyphenyl polyisocyanate;(iv) 1 to 20 pbw of n-ring oligomers of polymethylene polyphenyl polyisocyanate (n being greater than 3); and(v) 1 to 10 pbw of a mixture of uretonimine with from 5 to 50 parts by weight of a propoxylated propylene glycol (b) having a number average molecular weight of between 2000 and 6000, and a hydroxyl number of between 10 to 75. The resulting isocyanate prepolymer (I) has a free NCO of from 20 to 30 and a viscosity of from 50 to 500 cPs.

Abstract: The present invention is directed to polyurethane moldings produced via the RIM process. These polyurethane moldings have excellent reactivity, demold properties (at a 30 s demold), and good elongation and tear strength, and comprise the reaction product of an aliphatic polyisocyanate having a viscosity of less than about 20,000 mPa.multidot.s at 25.degree. C. and a NCO functionality of 2.3 to 4.0 with an isocyanatereactive component comprising b1) a relatively high molecular weight organic compound containing at least one of the groups selected from the group consisting of hydroxy groups and amine groups; and b2) a low molecular weight chain extender selected from the group consisting of diols, triols, primary amines, secondary amines, aminoalcohols, and mixtures thereof; in the presence of a catalyst. The OH:NH ratio of the chain extender is from 1:1 to 25:1.

Abstract: Process for preparing a flexible foam by reacting a polyisocyanate composition having an NCO value of 11-22% by weight with an isocyanate-reactive compound having a number average molecular weight of 1000-12000 using water as blowing agent.

Abstract: Process for preparing a flexible foam by reacting an isocyanate-terminated prepolymer having an NCO value of 5-18% by weight, a polyisocyanate having an NCO value of at least 25% by weight, 20-95 parts by weight, per 100 parts by weight of polyisocyanate, of an isocyanate-reactive compound of molecular weight of 1000-12000, and water.

Abstract: The invention provides a liquid polyisocyanate prepolymer composition which is a result of combining about 50 to 90 percent by weight of an isocyanate blend (a.) having 55 to 75 weight percent 4,4'-MDI, 17 to 27 weight percent 2,4'-MDI, 1 to 10 weight percent 3-ring MDI oligomer, and 1 to 15 weight percent n-ring MDI oligomer (n greater than 3); about 5 to 30 weight percent of a polyhydroxy containing polyol (b.) having a molecular weight of from 700 to about 6,000, and about 5 to 15 weight percent of a toluene diisocyanate (c.). The resulting isocyanate prepolymer composition has a free NCO content of from about 20 to 40 weight percent and particularly desirable flow characteristics. The invention further provides a method of making an isocyanate prepolymer composition, a process of making a polyurethane foam utilizing the isocyanate prepolymer composition of the invention, and polyurethane foams produced by the disclosed process.

Abstract: Polyisocyanate based organic aerogels having pore sizes less than 100 nm, densities in the range 10 to 800 kg/m.sup.3 and surface areas in the range 10 to 1500 m.sup.2 /g are provided.

Abstract: A flexible polyurethane foam which has a low density, enhanced impact resilience, improved compression set and excellent effect on the reduction of 6 Hz vibration transmissibility and is obtained by a reaction of an organic polyisocyanate composition, that is, a mixture of (a) polymethylenepolyphenyl isocyanate containing from more than 60 to 90% by weight of a two benzene ring compound and having a weight ratio [three benzene ring compound]/[four or more benzene ring compounds + less active ingredient] of 1.1-20.0, and (b) tolylene diisocyanate in a ratio (a)/(b) of 97.apprxeq.80/3.apprxeq.20 by weight, or by reaction of a prepolymer derived from said organic polyisocyanate composition and a specific polyol, with a resin premix comprising a water blowing agent and an active hydrogen containing compound; and a process for preparing the flexible polyurethane foam.

Abstract: A method for the preparation of flexible polyurethane foams by reacting a polyisocyanate containing at least 85% by weight of 4,4'-diphenylmethane diisocyanate or a liquid variant thereof with a polyol composition comprising at least one poly(oxyethylene-oxyalkylene) polyol, the composition having an average nominal hydroxyl functionality of from 2.5 to 6, a number average hydroxyl equivalent weight of from 1000 to 3000 and an average oxyethylene content of from 25 to less than 50% by weight and with water.

Abstract: A novel isocyanate reactive mixture is described which allows for the preparation of energy absorbing foams which meet Chrysler specification DC-640. The reactive mixture contains a) a filled polyol, b) a propylene oxide adduct of a mono-, di-, or trialkanolamine and c) a polyoxyalkylene polyamine. Foams prepared from the reactive mixture are also described.

Abstract: The invention provides a process for the preparation of a cellular polymeric product which comprises reaction of a polyisocyanate composition with an isocyanate-reactive composition having a functionality of at least 2, in the presence of a blowing agent and in the presence of an inert, organic liquid which is substantially insoluble in the reaction mixture and which is present as the disperse phase of an emulsion or a microemulsion, characterized in that the polyisocyanate composition comprises polymethylene polyphenylene polyisocyanate having a functionality of at least 2.5 and a urethane-modified, isocyanate-ended prepolymer, wherein the isocyanate functionality of the polyisocyanate composition is at least 2.3 and wherein the concentration of urethane linkages in the polyisocyanate composition is in the range from 1 millimole to 150 millimoles per 100 grams thereof.

Abstract: The invention provides a liquid polyisocyanate prepolymer composition which is a result of combining about 50 to 90 percent by weight of an isocyanate blend (a.) having 55 to 75 weight percent 4,4'-MDI, 17 to 27 weight percent 2,4'-MDI, 1 to 10 weight percent 3-ring MDI oligomer, and 1 to 15 weight percent n-ring MDI oligomer (n greater than 3); about 5 to 30 weight percent of a polyhydroxy containing polyol (b.) having a molecular weight of from 700 to about 6,000, and about 5 to 15 weight percent of a toluene diisocyanate (c.). The resulting isocyanate prepolymer composition has a free NCO content of from about 20 to 40 weight percent and particularly desirable flow characteristics. The invention further provides a method of making an isocyanate prepolymer composition, a process of making a polyurethane foam utilizing the isocyanate prepolymer composition of the invention, and polyurethane foams produced by the disclosed process.

Abstract: A method for the preparation of flexible polymeric foam by reacting a polyisocyanate component with an isocyanate-reactive component comprising at least 50% by weight of water, the polyisocyanate component comprising at least two polyisocyanate compositions, one of them being a low NCO isocyanate terminated prepolymer and the second being a high NCO polyisocyanate.

Abstract: Storage stable, liquid prepolymers of diphenylmethane diisocyanate containing urea and/or biuret groups are prepared by reacting an aminocrotonate with a mixture of isocyanates having a specified diphenylmethane diisocyanate isomer content. These prepolymers have isocyanate group contents of from about 5 to about 30%.

Abstract: An isocyanate terminated prepolymer based upon diphenylmethane isocyanates. This prepolymer is the reaction product of a diphenylmethane isocyanate mixture having from about 75 to about 95 wt % binuclear isomers and from about 5 to about 25 wt % polymeric isocyanate with a polyether polyol. The binuclear isomer content is generally from about 15 to about 40 wt % 2,4'-isomer and from about 2 to about 10 wt % 2,2'-isomer. The polyether polyol has a functionality of from about 3 to about 8, an OH number of from about 350 to about 1000 mg KOH/g and a molecular weight of from about 150 to about 1000. These prepolymers are particularly useful as starting materials for the production of light-colored, dimensionally stable rigid polyurethane foams.

Abstract: Polyaromatic polyisocyanates are modified by reaction with 0.1 to 10 weight %, preferably 2 to 7 weight % (based on polyisocyanate) of a polyether alcohol of molecular weight 206 to 948, obtainable by the reaction of alkylene oxides with C.sub.6 -C.sub.30, preferably C.sub.8 -C.sub.20, hydrocarbons containing 1 to 3 active H atoms, and are used for the production of rigid polyurethane foamed materials.