Abstract: An aromatic, isocyanate-base, polyurethane polymer and a process for preparing the polymer. The process comprises reacting, such as by spraying onto a substrate or an open mold, a caprolactone polyol with a methylene dipara phenylene isocyanate in the presence of a catalytic amount of a metallo catalyst, and a fast-curing and cross-linking amount of a curing agent comprising a polyalkanol amine, particularly a triethanol amine, to provide a fast-reaction aliphatic poilyurethane polymer. The reaction of difunctional caprolactone polyols with low functionality MDI in the presence of a tin catalyst and triethanol amine provides for flexible and rigid polymer films of substantially no porosity.

Abstract: The present invention is directed to a process for the production of oligourethanes having terminal mercapto groups by reacting organic polyisocyanates with sub-equivalent quantities of organic polyhydroxyl compounds and a mercapto-alkanol in the presence of at least one ester of phosphoric acid containing at least one hydroxyl group bound to phosphorus. The present invention is also directed to the mercapto group-containing oligourethanes obtainable by this process and their use as binders for oxidatively-hardenable coating and sealing compositions, additives for epoxide resins and cross-linking agents for plastics materials and plastics crude products containing olefinic double bonds.

Abstract: A polymerizable composition of polyurethane precursors is rapidly cured using energy-activated catalysts to provide polyurethanes. The polymerizable composition is comprised of polyisocyanates with polyols, fillers, coating aids, adjuvants, and a latent catalyst. Latent catalysts are ionic salts of organometallic complex cations. The cured polyurethanes are useful as abrasion resistant coatings, protective finishes such as furniture finishes and floor tiles, binders for magnetic media, adhesives, and have various applications in industries which use photoresist technologies such as graphic arts and electronics, and in the paint and ink industries.

Abstract: A two component structural adhesive which is composed of a mixture of an epoxy component which comprises a polyepoxide and a polyisocyanate and a hardener component which comprises a long chain, flexible polyamine and an epoxy resin homopolymerization catalyst is described.

Abstract: A porous or non-porous intumescent mass comprising one or more carbonization auxiliaries, one or more fillers and optionally one or more other auxiliary agents, produced by the reaction of a polyisocyanate with an isocyanate reactive compound, optionally containing phosphorus or boron, in the presence of polyepoxide. The intumescent mass according to the invention having good fire characteristics and can be used to produce structural elements for fire resistance purposes, fire barriers, textile coatings, linings, laminates and pipe insulators.

Abstract: A thermosetting reactive resin mixture is made from an organic polyisocyanate, a polyepoxide and a heat activatable catalyst. The catalyst is a tertiary or quaternary ammonium salt of an alkylating or acidic ester of an organic phosphonic acid or of phosphoric acid. The polyisocyanate and polyepoxide are used in quantities such that the equivalent ratio of isocyanate groups to epoxide groups is from 1.2:1 to 70:1. These mixtures may be heated to produce plastics having excellent heat resistance, moisture and abrasion resistance, low dielectric losses and excellent molding properties.

Abstract: Reaction of an aromatic dianhydride with a polycyclic aromatic primary diamine at a controlled reaction rate yields a diamic acid dianhydride oligomer. The oligomer may be a precursor for an imide foam which forms at low temperature, has outstanding physical characteristics, and is extremely heat resistant. The diamic acid moiety may be converted to diimide, and other modifications of the oligomer are disclosed. Other derivatives of the oligomers are also disclosed.

Abstract: The process for preparing a polyurethane which sets rapidly and can be demolded within minutes by the reaction of a bicyclic amide acetal, a polyol and a polyisocyanate in the presence of a plasticizer such as dioctyl phathalate and a polyurethane catalyst such as stannous octoate is described.

Abstract: An ultraviolet curable ink composition comprising, as main components,(A) a polyurethane poly(meth)acrylate obtained by reacting a polyisocyanate compound of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom or a methyl group, and n is an integer of from 1 to 20, with a hydroxyl group-containing (meth)acrylate, and having, in one molecule, at least two (meth)acryloyl groups and at least two urethane bonds,(B) a radical polymerizable low molecular weight compound, and(C) a photopolymerization initiator.

Abstract: A process is described for increasing the molecular weights of thermoplastic polyamides and polyesteramides by fluxing and homogenizing the subject polymers which have been prepared by the reaction of an organic diisocyanate and a dicarboxylic acid with an effective amount of an organic diisocyanate reagent at a temperature of at least about 150.degree. C.

Abstract: The invention provides salts of methyl phosphonic acid and its mono- or di-methyl ester with certain amines. The salts are useful flame retardant additives for polyurethanes and polyisocyanurates.

Abstract: Substantially linear, segmented polyester-amides are disclosed which contain aromatic residues in the hard segments and as soft segments the residues of polycarbonate diols of molecular weight from about 400 to about 4000.The polymers are characterized by the unexpected combination of excellent hydrolytic stability, thermal stability, and low temperature flexibility.

Abstract: Flame retardant isocyanate addition products are made by reacting an isocyanate with a compound selected from the group consisting of 1-phosphonoethane-2-carboxylic acid-tri-C.sub.1 -C.sub.4 -alkyl esters, 1-phosphonopropane-2-carboxylic acid-tri-C.sub.1 -C.sub.4 -alkyl esters and mixtures thereof. Known isocyanate-reactive compounds, blowing agents, catalysts, additives and auxiliary agents may optionally be included in the reaction mixture. These flame retardant products are useful in construction applications such as insulation panels for roof insulation.

Abstract: The present invention is directed to a process for the production of compression-molded materials by the compression molding lignocellulose-containing materials mixed and/or impregnated with polyisocyanates as binder in the presence of catalysts, the improvement wherein the catalysts used are latent, heat-activatable catalysts based on ammonium salts of the type which can be obtained by reacting(i) monofunctional or polyfunctional, primary, secondary and/or tertiary amines with(ii) alkyl esters of acids of phosphorus.or secondary and/or tertiary amines (i) withacidic alkylester of acids of phosporous (ii) under neutralization in substantially equivalent quantities.

Abstract: The invention is phosphono-s-triazines corresponding to the formula ##STR1## wherein: X is separately in each occurrence chlorine, bromine, haloalkyl or alkyl;Y is separately in each occurrence hydrogen, chlorine or bromine;R is separately in each occurrence hydrogen, hydrocarbyl, CH.sub.2 Y, CH.sub.2 OH or CH.sub.2 OC(R.sup.1).sub.3 wherein R.sup.1 is alkyl;a is an integer from 0 to 2 inclusive; andb is an integer from 1 to 3 inclusive, with the proviso that the sum of a and b equal 3, and with the further proviso that at least one R is CH.sub.2 OH or CH.sub.2 OC(R.sup.1).sub.3.

Abstract: The invention relates to a process for isocyanurating hexamethylene-diisocyanate containing polyol adduct thereof using a novel catalyst and to a paint composition formed from of the product of the above mentioned process and polyol, and to the composition yielding a paint film showing an excellent light resistance and weather resistance, especially high yellowing resistance.

Abstract: A binder composition containing a phenolic resin, a polyisocyanate, a phosphorus based acid and optionally an acid halide and/or a base, and methods of making and using the same.

Abstract: Polyhydroxybutadiene compounds are storage stabilized against reactivity changes by incorporating therein an effective amount of a di or triphenyl phosphine compound of the formula ##STR1## wherein each x is hydrogen, a halogen or an alkyl or alkoxy group having from 1 to 10 carbon atoms and y is an alkyl group having from 1 to 10 carbon atoms or an aryl group which may be substituted with a halogen or an alkyl or alkoxy group having from 1 to 10 carbon atoms.

Abstract: Homogeneous storable mixtures containing small quantities of salts and having a high mixed hydroxyl number of mixed hydroxyl/amine number are made by mixing (a) a polyoxyalkylene polyol and/or polyolamine and/or polyamine based on an alkyloxirane having a molecular weight of from 400 to 12,000, (b) a low molecular weight polyol which is not completely miscible with (a) and a solution-promoting additive in quantities such that for every 100 parts of (a), from 1 to 200 parts of (b) and from 0.01 to 10 parts of (c) are present. The solution-promoting additives are salts of cations of Groups IA, IIA and IIIA of the Periodic System of Elements or ammonium or mono- to tetra-alkylammonium ions and anions formed by removing at least one proton from an acid having a K.sub.s -value of at least 10.sup.-7. These mixtures are particularly useful in the production of polyurethanes.

Abstract: Polyurethane resins having high rigidity and improved physical properties such as mechanical strengths and heat resistance are obtained by reacting a polyisocyanate with a polymer polyol derived from an epoxy-containing monomer, for example, glycidyl esters of unsaturated mono- and dicarboxylic acids, and a polyol, and bringing about ring-opening reaction of epoxy radicals in the presence of an epoxy curing agent, simultaneously with, or before or after the urethane-forming reaction.

Abstract: A binder containing a phenolic resin; a polyisocyanate; a curing component, and a phosphorus halide and use thereof.

Abstract: The present invention relates to optionally foamed intumescent masses obtained by reacting(1) polyisocyanates with a mixture containing(2) polyethers having an average OH number of from about 150 to 500 and obtained by the chemical addition of alkylene oxides having an ethylene oxide content of from about 50 to 100% by weight to low molecular weight starters, and/or(3) hydroxyl polyesters having an OH number of from about 100 to 350 obtained by the reaction of aliphatic, cycloaliphatic, araliphatic and aromatic polycarboxylic acids having 2 to 10 carbon atoms with at least two polyols selected from two different groups of the three following groups:(a) hydroxyl compounds with a molecular weight of up to about 200 having more than three OH groups,(b) hydroxyl groups with a molecular weight of up to about 150 having three OH groups, and(c) hydroxyl compounds with a molecular weight of up to about 80 having two OH groups, wherein one of the polyols belongs to group (a), and(4) a phosphate of the melamine phospha

Abstract: Compositions which are storage stable at room temperature are made from an organic polyisocyanate, a compound containing at least two isocyanate-reactive groups and a latent catalyst. The latent catalyst is formed from an amine and an alkylating ester of an acid of phosphorus. These compositions react to form isocyanate polyaddition products when exposed to a temperature of 60.degree. C. or higher. These compositions are useful in the production of adhesives, foamed and non-foamed plastics and coatings.

Abstract: The invention is phosphorus compounds containing .alpha.-halo hydroxyalkyl or .alpha.-halo t-alkoxyalkyl groups corresponding to the formula ##STR1## wherein R independently in each occurrence is alkylene, haloalkylene, alkenylene, haloalkenylene, phenylene, diphenylene, halophenylene, dihalophenylene, and oxyalkylene;R.sup.1 independently in each occurrence is hydrogen, CH.sub.2 OR.sup.3, CH.sub.2 OH, haloalkyl, phenyl, halophenyl or methyl phenoxy;R.sup.2 independently in each occurrence is haloalkyl, phenyl, haloaryl or alkyl;R.sup.3 independently in each occurrence is t-alkyl;X independently in each occurrence is bromine or chlorine;a is independently in each occurrence 1 or 2; andb is independently in each occurrence 0 or 1,with the proviso that at least one R.sup.1 is CH.sub.2 OR.sup.3 or CH.sub.2 OH.

Abstract: High molecular weight aromatic polyamines are produced by hydrolyzing a polyisocyanate having an isocyanate content of from 21 to 52.5% and an isocyanate-reactive group-containing compound having a molecular weight of from 400 to 10,000 in the presence of an excess of water. The reactants are used in quantities such that the equivalent ratio of isocyanate to isocyanate-reactive groups is from 0.1 to 5. Further, water is used in an amount such that the equivalent ratio of water to isocyanate groups is greater than 1. Low molecular weight compounds containing isocyanate-reactive groups, solvents, basic catalysts and urethanization catalysts may also be included in the mixture to be hydrolyzed. The hydrolysis is carried out at a temperature of from -20.degree. to 175.degree. C. The product amine is isolated from the reaction mixture by procedures such as phase separation, extraction and distillation. The polyamines thus-produced are particularly useful in the production of polyurethanes.

Abstract: The present invention relates to a process for the preparation of polyisocyanates containing isocyanurate groups by the trimerization of a proportion of the isocyanate groups of organic polyisocyanates and termination of the trimerization reaction by the addition of a catalyst poison, characterized in that the trimerization catalysts employed are quaternary ammonium salts based on the reaction product of tertiary amines and esters of acids of phosphorus which have an alkylating action. The invention also relates to the use of the polyisocyanates with isocyanurate groups obtainable by this process, optionally in a form freed from excess starting polyisocyanates and/or optionally in a form in which the isocyanate groups are blocked with blocking agents, as isocyanate components for the preparation of isocyanate-polyaddition products, especially polyurethanes.

Abstract: Hydroxylated lecithins are employed as mold release agents in the preparation of molded articles from polyurethane-forming compositions. Polyol compositions containing such mold release agents are also disclosed.

Abstract: Disclosed is a polyurethane composition of multi-pack type, curable at ambient temperature, which comprises an isocyanate component having oxadiazinetrione ring, an active hydrogen component and a Lewis base whose basic site has no hydrogen active to NCO group and a process for producing polyurethane from the composition.The composition has excellent curability at ambient temperature and is useful for coatings, adhesives and elastomers as high solid content type or solventless type. The cured product polyurethane has good mechanical properties.

Abstract: An improved polyurethane binder system is provided which incorporates organic phosphorous compounds that impart longer bench life to the binders making them more useful for preparing moldable compositions such as foundry cores and molds.

Abstract: A composition comprises polyurethane, a two-component flame retardant system consisting of an additive first flame retardant containing organophosphorus, and a second flame retardant containing organochlorine or organobromine.The composition of the invention may be employed for polyurethane foams, especially rigid foams.Diminished combustibility for rigid foam is measured by a flame-spread index less than 75 and a smoke developed index less than 450 when subjected to ASTM Test E-84, Surface Burning Characteristics of Building Materials.Dimethyl methylphosphonate is a representative additive organophosphorus first flame retardant. Trichloroisopropyl alcohol is a representative second flame retardant containing organochlorine.

Abstract: The addition of a small amount of a halogen compound, e.g. chloroethyl phosphate, in a process producing elastomeric polyurethane RIM parts using tertiary amines as the chief catalyst component results in scavenging the residual amines after the part has been cured by annealing. The parts from such a process can be coated with a wide variety of enamels having a high solids content and completely cured to result in a higher degree of adhesive between the coating and the part's surface than those parts from a process without the use of such a halogen.

Abstract: Novel, low viscosity, high solids paint compositions have been created which provide durable, high gloss surface finishes when they are applied to and cured over suitable substrates. The paints are based on urethane binder resins formed by initially reacting a hindered piperidinol ultraviolet stabilizer with a stoichiometric excess of aliphatic polyisocyanate. This reaction product is in turn reacted with a stoichiometric excess of polyether polyols. The paint compositions are cured by crosslinking the urethane binder resins at the unreacted functional hydroxyl groups of the polyol constituents by means of acid catalyzed, melamine formaldehyde crosslinking agents. Cure can generally be fully accomplished in a short time at temperatures below about 250.degree. F. The cured paint has piperidine groups chemically incorporated within its molecular structure to effectively inhibit the degradation of the urethane linkages and the loss of gloss by ultraviolet radiation.

Abstract: Poly(epoxy-polyisocyanate) silicate foamed products are produced by mixing and reactng an epoxide compound, an oxidated silicon compound and a polyisocyanate in the presence of a Lewis acid. The foam produced by this process may be utilized for thermal and sound insulation.

Abstract: This invention is directed to a polyurethane product produced by a one step process, in the absence of a polymerization catalyst, with reactants, and additives, if any, being initially intermingled in the ambient room temperature range and reacted with intermingling in the absence of externally added heat. The reactants are (1) aliphatic, aromatic, or cycloaliphatic having at least two isocyanate groups and (2) diol/polyol compounds having at least two sterically unhindered hydroxyl groups. The product is a liquid, homogeneous adhesive material characterized by a natural absence of polymerization catalyst residue and capable of being cured because of the presence of unreacted isocyanate groups, the isocyanate reactant being charged in excess of the stoichiometric requirement of the diol/polyol reactant.

Abstract: The use of an organic phosphorus acid compound to extend the pot life of urethane reaction mixtures is disclosed.

Abstract: A heat-resistant heterocyclic polymer consisting of units of the general formula ##STR1## wherein R, R.sup.1 and X are as defined hereinbelow anda method for producing heat-resistant heterocyclic polymers, consisting in that, at a temperature of 90.degree. to 400.degree. C., there is conducted a reaction of polyfunctional nitrile-containing compounds with polyfunctional isocyanates.The proposed polymers are stable at temperatures from 300.degree. to 350.degree. C. Materials based thereon are capable of retaining their properties at a temperature of up to 400.degree. C. for long periods of time. The method is simple and can be effected without isolation, purification or drying the polymer, which allows combining the process of producing the polymer with that of producing a finished article.

Abstract: The instant invention relates to a process for producing stable equilibrium mixtures of carbodiimides, uretone imines and organic isocyanates and storage-stable solutions of carbodiimides and uretone imines in polyisocyanates which are free from carbodiimide groups. Either the carbodiimide, or the uretone imine, or both, may contain isocyanate groups. The invention relates to the process for the preparation of these products by so-called heterogeneous catalysis and the use of these products for the production of polyurethane resins.

Abstract: Polyimide-amide-carboxylic acids produced by reacting an aromatic diamine with an aromatic tetracarboxylic acid dianhydride in amounts of 1.5 to 2.0 moles of the latter per mole of the former in the presence of an inert solvent, and reacting the resulting intermediate reaction product with an aromatic diisocyanate in about equivalent amounts at a temperature of 50.degree. to 100.degree. C. while removing generated carbon dioxide from the reaction system are good in heat resistance, wear resistance, chemical resistance, etc.

Abstract: The instant invention is directed to a process for the production of pneumatic tires having particularly high dynamic strength and low plastic deformability comprising casting or centrifugally casting the following liquid reaction system whose rapid hardening requires temperatures of at most 85.degree. C.:(A) prepolymers or semiprepolymers of specified isocyanates and a polyol or polyol mixture having a hydroxyl functionality of 2.0 to 2.2 and an average molecular weight of from 1,000 to 3,000, wherein the molar ratio of polyol to diisocyanate is from 1:1.5 to 1:4.0,(B) specific aromatic diamine chain extenders,(C) catalysts, and(D) auxiliaries.

Abstract: Novel thermoplastic polyester polyurethanes are disclosed which are obtained by reacting a polyester diol, a difunctional extender, a methylenebis(phenyl isocyanate), and from about 0.0025 mole to about 0.03 mole per equivalent of isocyanate of a monocarbodiimide product derived from a methylenebis(phenyl isocyanate) or the corresponding uretidinedioneimine adduct thereof with said latter methylenebis(phenyl isocyanate).The polyester polyurethanes are characterized by a combination of thermoplasticity, extremely good hydrolytic stability which cannot be diminished by solvent action, good physical properties, particularly tensile strength and elongation, and enhanced clarity of molded articles.

Abstract: This invention relates to a process for the preparation of finely divided, stable and relatively low viscosity dispersions of ionic polyisocyanate polyaddition products in compounds having hydroxyl groups by reacting(1) organic polyisocyanate with(2) compounds having primary and/or secondary amino groups and/or primary hydroxyl groups in(3) compounds having at least one hydroxyl group,with the proviso that compounds (3) have secondary hydroxyl groups if compounds with primary hydroxyl groups are used as compound (2), and further characterized in that at least one of the components (1) or (2) has groups which are ionic and/or capable of salt formation.

Abstract: This invention relates to a process for the production of non-cellular polyurethane ureas elastomers using a chain-extender mixture produced from asymmetrically alkyl-substituted anilines by condensation with formaldehyde. The chain-extending agents used in the instant invention show medium reactivity to compounds containing isocyanate groups. These chain-extending agents may be processed both in high-pressure and in low-pressure metering and mixing units because they are either liquid at room temperature or can be melted at relatively low temperatures (below 55.degree. C.). The homogeneous, i.e. non-cellular, polyurethane urea elastomers obtained in the instant invention are distinguished by having excellent mechanical properties.

Abstract: Polymers of anionically polymerized monomers such as mono-olefins, conjugated dienes, vinyl substituted aromatics, vinyl substituted pyridine, vinyl substituted quinolines, various aldehydes, various epoxides, various oxetanes, various oxygen-containing compounds, and the like are produced and end capped with a polyisocyanate or polyisothiocyanate having the formula R--N.dbd.C.dbd.X).sub.n wherein R is a hydrocarbon, n is 2 or 3, and X is oxygen or sulfur. Such end capped polymers, of course, contain one reacted or connected isocyanate or isothiocyanate group and at least one free isocyanate or isothiocyanate end group, which free end group(s) reacts with an amide to give an imide end group. The imide terminated polymer is then hydrolyzed to form a stable amine terminated polymer. The reaction of the amide compound with the isocyanate(s) or isothyiocyanate(s), followed by hydrolysis, results in the replacement of the free isocyanate or isothiocyanate end group(s) with an amine group(s).

Abstract: The present invention relates to a new process for the preparation of polyisocyanates containing isocyanurate groups by the partial trimerization of the isocyanate groups of 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (also known as isophorone diisocyanate and abbreviated IPDI), using catalysts which accelerate the trimerization of isocyanate groups, characterized in that the catalysts used are quaternary hydroxyalkyl ammonium hydroxides containing at least one hydroxyalkyl group. The present invention also relates to the polyisocyanates containing isocyanurate groups produced according to this process and to their use, optionally in the form of products which are blocked with blocking agents for isocyanate groups, as isocyanate components for polyurethane lacquers.

Abstract: To a dispersion of a complex of 3 moles of 4,4'-methylenedianiline with 1 mole of a specified inorganic salt in an inert liquid, which still contains some free methylenedianiline, there is added, with agitation, at least 0.5 equivalent of an organic isocyanate per equivalent of free methylenedianiline. Then, there is added, while continuing agitation, at least 0.5 weight % of lecithin. The resulting dispersion is a good curing agent for isocyanato-terminated polyurethane prepolymers. Compositions containing both the prepolymer and the curing agent of this invention have good shelf stability at room temperature and cure to polyurethane products having good physical properties and hydrolytic stability.

Abstract: A polyimide foam is provided which has improved resistance to crumbling and to high temperatures. The foam is produced by reacting polymethylene polyphenylisocyanate (PAPI) with benzophenone-3,3',4,4'-tetracarboxylic acid dianhydride (BTDA) in the presence of furfuryl alcohol and concentrated phosphoric acid (PA). The ratio of PA to PAPI, (PA/PAPI), must be approximately 20 to 26% by weight.

Abstract: A process of forming polyurethane compositions which emit reduced amounts of toxic smoke on burning is described. The process comprises reacting a mixture of an organic compound having two or more active hydrogen atoms, an organic polyfunctional isocyanate, a catalyst and at least one metal salt of an aliphatic or alicyclic monocarboxylic acid wherein the metal is cobalt, copper, nickel or manganese. The metal salt is added to the mixture in an amount which is sufficient to reduce the formation of toxic substances when the polyurethane is ignited.

Abstract: The use of polyisocyanates as binders in the preparation of particle boards is subject to the drawback that the boards exhibit a tendency to adhere to the face of the platens used in their formation. This problem is minimized by incorporating minor amounts of a mixture of certain mono- and di- (saturated or unsaturated aliphatic) acid phosphates or the corresponding pyrophosphates, into the polyisocyanate to be used as binder. The polyisocyanates and the acid phosphates and or pyrophosphates, are applied to the particles separately, or after preblending one with the other. Whether the components are applied separately or in combination one with the other, they can each be applied either neat or in the form of an emulsion or emulsions.

Abstract: The use of polyisocyanates as binders in the preparation of particle boards is subject to the drawback that the boards exhibit a tendency to adhere to the face of the platens used in their formation. This problem is minimized by utilizing, in association with the polyisocyanate to be used as binder, minor amounts of one or more phosphates or thiophosphates of the formula: ##STR1## where R=alkyl (C.sub.3 and higher), alkenyl (C.sub.3 and higher), aryl, alkyl-substituted aryl, ##STR2## (where R.sub.2 is alkyl, aryl, or alkyl-substituted aryl, A and B are H, methyl, chloromethyl, 2,2,2-trichloromethyl, m=1-25) and lower-alkyl substituted by from 1 to 2 acyloxy groups where acyl is the residue of an aliphatic carboxylic acid having at least 2 carbon atoms; R.sub.1 is Cl, Br, lower-alkoxy, lower-alkylmercapto, arylamino, mono(lower-alkyl)amino, di(lower-alkyl)amino, hydroxy(lower-alkylene)oxy, aryloxy, hydrocarbylureido, and an enol residue; X=O or S and n=1 or 2.

Abstract: A process is disclosed for the preparation of liquid, storage-stable, polyisocyanate compositions containing a release agent formed in situ which compositions are useful, for example, as binder resins in the formation of particle boards which latter, because of the presence of the release agent, show no tendency to adhere to the face of metal platens used in their formation. The process comprises heating an organic polyisocyanate (polymethylene polyphenyl polyisocyanate preferred) with an acid phosphate (e.g. a mixture of mono- and di-alkyl acid phosphates) under conditions controlled as to time and temperature so as to yield a product which is storage stable and shows no tendency to deposit solid or to separate into two liquid phases.