Abstract: Disclosed herein is a porous membrane having an immobilized enzyme wherein the enzyme is immobilized within pores which are three-dimensionally connected to each other. The porous membrane having the immobilized enzyme is three-dimensionally crosslinked in a molecular level wherein nanopores of 5 to 100 nm are interconnected, so that the immobilized enzyme may be in contact with a reactant in all directions, and the reaction solution may be easily diffused, thereby proceeding with the catalytic reaction fast and conveniently without deterioration of material transport.

Abstract: The present invention relates to new, urethane-group-containing polyisocyanates based on aliphatic and/or cycloaliphatic diisocyanates, and to their use.

Abstract: Described are novel ricinoleic acid/12-hydroxy stearic acid-based diisocyanates, which are useful as monomers to form polymers, which have applications inter alia as medical devices.

Abstract: Disclosed are novel bioabsorbable and biodegradable monomer compounds, bioabsorbable and biodegradable polymers therefrom, and methods of making such monomers and polymers, which are useful in pharmaceutical delivery systems, tissue engineering applications, tissue adhesives products, implantable medical devices, foams and reticulated foams for wound healing and drug delivery, bone hemostats and bone void fillers, adhesion prevention barriers, meshes, filters, stents, medical device coatings, pharmaceutical drug formulations, consumer product and cosmetic and pharmaceutical packaging, apparel, infusion devices, blood collection tubes and devices, other medical tubes, skin care products, and transdermal drug delivery materials.

Abstract: The present invention relates to the discovery of new class of hydrolysable amino acid derivatives and absorbable polyester amides, polyamides, polyepoxides, polyureas and polyurethanes prepared therefrom. The resultant absorbable polymers are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention, bone wax formulations, medical device coatings, stents, stent coatings, highly porous foams, reticulated foams, wound care, cardiovascular applications, orthopedic devices, surface modifying agents and other implantable medical devices. In addition, these absorbable polymers should have a controlled degradation profile.

Abstract: Processes comprising: (a) providing a composition comprising at least one silane-terminated polyurethane preploymer prepared by a process comprising: reacting (A) at least one polyether having a number average molecular weight (Mn) of 2000 to 8000 g/mol, and comprising 10 to 30 wt % ethylene oxide units based on all alkylene oxide units in the polyether; with (B) at least one isocyanate and alkoxysilane group-containing compound of the formula (I): wherein each of X, Y, and Z independently represents a C1-C8 alkyl or a C1-C8 alkoxy residue, with the proviso that at least one of X, Y, and Z represents a C1-C8 alkoxy group; and wherein R is an at least bifunctional, organic residue; (b) foaming the composition, and (c) curing the foamed composition in the presence of water; and uses of polyurethane foams prepared thereby.

Abstract: A porous polyurea material may be prepared by polymerization and crosslinking of tetra(4-aminophenyl)methane or tetra(4-aminophenyl)silane with a monomer having two to four isocyanate (—NCO) groups, or by polymerization and crosslinking of tetra(4-isocyanatophenyl)methane or tetra(4-isocyanatophenyl)silane with a monomer having two to four amino groups. The method includes: mixing an organic solution of tetra(4-aminophenyl)methane with an organic solution of a monomer having two to four isocyanate groups; reacting the mixed solution under a nitrogen atmosphere; and drying a semi-solid or solid material formed by gelation of the reaction solution, or adding the reaction solution to a non-solvent before gelation of the reaction solution to form a precipitate, followed by drying, or applying the reaction solution to a substrate before gelation of the reaction solution, followed by drying.

Abstract: The present invention relates to the discovery of a new class of hydrolysable isocyanates, hydrolysable branched polyols and branched absorbable polyesters and polyurethanes prepared therefrom. The resultant absorbable polymers are useful for drug delivery, stents, highly porous foam, reticulated foam, tissue engineering, tissue adhesives, adhesion prevention, bone wax formulations, medical device coatings, surface modifying agents and other implantable medical devices. In addition, these absorbable polymers can have a controlled hydrolytic degradation profile.

Abstract: Disclosed is a thermoplastic resin foam which is obtained by subjecting a thermoplastic resin composition containing a thermoplastic elastomer and an active-energy-ray-curable resin to foam molding to give a foamed structure, and irradiating the foamed structure with an active energy ray to allow the active-energy-ray-curable resin to form a cross-linked structure in the foamed structure. Also disclosed is a thermoplastic resin foam which is obtained by subjecting a thermoplastic resin composition containing a thermoplastic elastomer, an active-energy-ray-curable resin, and a thermal cross-linking agent to foam molding to give a foamed structure, irradiating the foamed structure with an active energy ray to allow the active-energy-ray-curable resin to form a cross-linked structure in the foamed structure, and heating the resulting foamed structure bearing the cross-linked structure to thereby allow the thermal cross-linking agent to form another cross-linked structure in the foamed structure.

Abstract: The present invention relates to the discovery of new class of hydrolysable amino acid derivatives and absorbable polyester amides, polyamides, polyepoxides, polyureas and polyurethanes prepared therefrom. The resultant absorbable polymers are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention, bone wax formulations, medical device coatings, stents, stent coatings, highly porous foams, reticulated foams, wound care, cardiovascular applications, orthopedic devices, surface modifying agents and other implantable medical devices. In addition, these absorbable polymers should have a controlled degradation profile.

Abstract: A microcellular polyurethane or polyurethane-urea foam elastomer includes the reaction product of (A) with (B) and/or water, a blowing agent, a catalyst forming urethane and/or ureic groups wherein: (A) is a prepolymer having a —NCO free group content included between 2%-25% (% w/w), which includes the reaction product of (a1) one or more aliphatic, cycloaliphatic and/or aromatic diisocyanates excluding 3,3?-dimethyl-4,4?-diphenylene diisocyanate, or one or more polyisocyanates or mixture of diisocyanates and polyisocyanates; with (a2a) one or more polyester macrodiols, a number of —OH groups per molecule equal to about 2; (B) is a compound selected from (b1) a diol or polyol; (b2) a primary or secondary aliphatic, cycloaliphatic amine or aliphatic, cycloaliphatic aromatic disecondary diamine or a blocked amine; (b3) one or more polyester macrodiols having a number of —OH group per molecule equal to about 2; (b4) a mixture formed of two or more compounds (b1), (b2) and (b3).

Abstract: Absorbable polyurethanes, polyamides and polyester urethanes prepared from at least one compound selected from: or the corresponding diamines or diisocyanates thereof, wherein each X independently represents —CH2COO—, —CH(CH3)COO—, —CH2CH2OCH2COO—, —CH2CH2CH2CH2CH2COO—, —(CH2)yCOO— where y is 2 to 4 or 6 to 24, or —(CH2CH2O)z?CH2COO— where z? is 2 to 24; each Y represents —COCH2O—, —COCH(CH3)O—, —COCH2OCH2CH2O—, —COCH2CH2CH2CH2CH2O—, —CO(CH2)mO— where m is 2 to 4 or 6 to 24, or —COCH2O(CH2CH2O)n— where n is 2 to 24; R? is hydrogen, benzyl or straight-chained or branched alkyl; p is 1 to 4; and Rn represents one or more members selected from H, alkoxy, benzyloxy, aldehyde, halogen, carboxylic acid and —NO2, which is attached directly to an aromatic ring or attached through an aliphatic chain. Absorbable polymers prepared from these compounds are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention and other implantable medical devices.

Abstract: The invention relates to a polyisocyanurate comprising isocyanurate rings linked by linker groups coupled to the nitrogen atoms of said rings. The polyisocyanurate may be microporous or mesoporous or both microporous and mesoporous.

Abstract: Hydrophilic polyurethane urea foams which are made without toxic, leachable additives are disclosed. High molecular weight, isocyanate-terminated, ethylene oxide-rich prepolymers are used in place of surfactants to make the foams.

Abstract: Polyurethane/urea foams are derived from prepolymers having branched chain linked isocyanate end groups and components containing isocyanate reactive imino/enamino-functional compounds.

Abstract: A new polyurethane as well as a process for preparing same is disclosed. The new polyurethane contains therein a hard segment derived from at least one polyhydroxy substance selected from the group consisting of cellulosic substances, hemi-cellulosic substances and lignic substances, and is excellent in mechanical and thermal characteristics as compared with the existing polyurethanes. The new polyurethane can be prepared according to a method known per se, using the polyhydroxy substance alone or in mixture with a polyol compound as reactants to be polycondensed with a polyisocyanate.

Abstract: A polyisocyanate composition, suitable for use in the production of elastomers by the RIM process, or foams, said composition being the product of reacting an imino-functional or enamine-containing compound having a molecular weight of at least 1000 with a stoichiometric excess of an organic polyisocyanate.

Abstract: This invention relates to a process for coloring polyurethane resins during the production of same with reactive colorants derived from novel polyalkoxytrifluoroaniline intermediates. These colorants impart increased brightness in shade for both aromatic and heteroaromatic derivatives and increased resistance to stannous octanoate catalyst over conventional polymeric colorants derived for heteroaromatic compounds. These novel colorants have the structure: ##STR1## wherein R.sub.1 is selected from H, a lower alkyl group containing from 1 to about 10 carbon atoms, CH.sub.2 Cl, CH.sub.2 OH, phenyl or ##STR2## where R.sub.6 is H or a lower alkyl group containing from 1 to about 9 carbon atoms; R.sub.2 is selected from OH, NH.sub.2 or SH; R.sub.3 is selected from a lower alkyl group containing from 1 to about 9 carbon atoms, cyanoalkyl, acetoxyalkyl or ##STR3## where R.sub.1 and R.sub.2 are as given above; R.sub.4 is H, CF.sub.

Abstract: A light stable, fast reacting, aliphatic polyurethane sprayable coating composition and injectable open molding material is prepared by reacting an A side composition comprising a trimerized or biuret polymethylene polyisocyanate prepolymer with a B side composition comprising an admixture of an alkoxy polyalkylene glycol, such as methoxypolyethylene glycol and an aromatic polyamine such as a diethyl toluene diamine to provide a polyurethane reaction product which rapidly gels, may be quickly removed from the mold, has good green strength and high temperature resistance and is characterized by good ultraviolet or light stability properties. Optionally, the B side composition may contain a catalytic amount of a metal carboxylate like lead napthenate. The A and B side compositions may be sprayed onto a mat in an open mold and also may be sprayed in conjunction with chopped glass fibers, to form a glass-fiber spray coating.

Abstract: Reinforced cellular or noncellular molded polyurethane parts are prepared by heating a mixture of reinforcing materials and a heat-curable composition of polyisocyanates and polyols in an open or closed mold, said composition being storage-stable at room temperature and containing, optionally, auxiliaries and additives. In said composition, the polyisocyanate is dispersed in the form of discreet particles having particle diameters from 0.1 to 150 .mu.m in the polyol and the polyisocyanate particles are deactivated on their surfaces such that from 0.01 to 20 equivalent percent of the total available isocyanate groups are deactivated and such that the ratio of free isocyanate groups to hydroxyl groups is from 0.7:1 to 2.5:1.The polyurethane molded parts are suitable for use as self-supporting trim parts, reinforcement parts, or molded parts for various applications.

Abstract: An improved game ball is manufactured from a polyurethane foam prepared from a hydroxyl-containing diene polymer, a catalyst system comprised of a tin compound and a tertiary amine and a surfactant system comprised of a non-hydrolyzable silicone-polyether copolymer and a polydialkylsiloxane.

Abstract: Liquid carbodiimide-modified organic polyisocyanates are prepared by reacting a crude polymethylene polyphenylene polyisocyanate containing no more than 70 weight percent diphenylmethane diisocyanate with an isomer mixture of 40 to 100 weight percent 4,4'-, 0 to 50 weight percent 2,4- and 0 to 10 weight percent 2,2'-diphenylmethane diisocyanate and having an average functionality of 2.1 to 2.7 and a free NCO content of at least 30 percent weight percent in the presence of an effective amount of carbodimidization catalyst. Polyisocyanurate-polyurethane foams prepared by reacting the modified polyisocyanates and polyols selected from the group consisting of diethylene glycol and ethylene oxide adducts of trimethylolpropane, trimethylolethane, glycerine, pentaerythritol, .alpha.-methylglucoside, sucrose, toluene diamine and methylene dianiline in the presence of trimerization catalysts exhibit improved compression strengths and K-factors with low friability and smoke density.

Abstract: A composition for polyurethane foam comprising (a) polyols containing at least one of alkylene oxide adducts of aniline-formaldehyde condensates and alkylene oxide adducts of reduced compounds of nitrated toluenes in an amount of 30 to 70% by weight of the polyols, (b) at least one isocyanate of the formula: ##STR1## a fire retardant, together with one or more conventional catalysts, foam stabilizers, blowing agents and the like additives, can give fire retardant, high impact and heat resistant urethane foams.

Abstract: Reaction products of an organic polyisocyanate with a reactive diamine such as bis(4-aminocyclohexyl)methane and isophorone diamine, prepared at a temperature of between 135.degree. C. and 200.degree. C., are used to prepare polyurethanes useful for comfort cushioning applications such as automotive seating, furniture, mattresses, and large automotive body panels.

Abstract: A method of reducing the formaldehyde emissions from formaldehyde condensation polymers is disclosed. A substance having two or more amide linkages, such as a polyacrylamide polymer is incorporated in the polymer solution immediately or shortly before use, the acrylamide polymer reacting with free formaldehyde in the solution or that generated as a result of hydrolytic breakdown of the formaldehyde condensation polymer. The incorporation of polyacrylamide polymers in a urea-formaldehyde resin solution used in the production of urea-formaldehyde insulating foams is of particular benefit.

Abstract: The instant invention is directed to a substituted polyisocyanate or polyisocyanate mixtures of the diphenyl methane series containing chlorosulfonyl groups, a process for the preparation thereof and the use thereof for the preparation of polyisocyanate polyaddition compounds.

Abstract: A carbamylbiuret-modified polyisocyanate of the formula: ##STR1## wherein n is an integer of from about 1 to about 20; R is a divalent radical containing from about 1 to about 18 carbon atoms; and Y is a divalent radical selected from the group consisting of: ##STR2## wherein D is selected from the group consisting of O, S, and NH; X, X', and X" are independently selected from the group consisting of oxygen and sulfur; R.sup.2 and R.sup.3 are independently selected from the group consisting of aryl of from about 6 to about 18 carbon atoms, alkyl containing from about 1 to about 6 carbon atoms, and cycloalkyl containing from about 3 to about 7 carbon atoms, provided that each of R.sup.2 and R.sup.3 differs from R; and R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are independently selected from the group consisting of hydrogen, alkyl containing from about 1 to about 6 carbon atoms, cycloalkyl containing from about 3 to about 7 carbon atoms, phenyl, and benzyl.

Abstract: A process for the production of a modified isocyanate by reacting a composition containing carbodiimide groups and free isocyanate groups with a diester of an aliphatic dicarboxylic acid in the presence of oxalic or formic acid.The process permits the production of liquid forms of diphenylmethane diisocyanate useful in the manufacture of polyurethanes.

Abstract: The instant invention is directed to a process for the production of inorganic-organic synthetic materials having high strength, elasticity, dimensional stability under heat, and flame resistance, consisting of a polymer-polysilicic acid gel composite material in the form of a solid/solid xerosol, said process comprising mixing(a) an organic polyisocyanate,(b) an aqueous basic solution and/or an aqueous basic suspension having an inorganic solid content of from 20-80% by weight preferably from 30-70% by weight,(c) a flowable inorganic compound and optionally(d) catalysts and other additives and allowing the resulting mixture to react, characterized in that mixing is carried out by first combining components (a) and (b), optionally with the addition of all or part of component (d), to form a stable primary dispersion and thereafter adding component (c), optionally the addition of all or part of component (d), to form a final dispersion.

Abstract: This invention relates to new diisocyanates containing urea groups which are liquid at room temperature or can be liquefied by heating to a temperature of up to 80.degree. C. These novel diisocyanates may be in the form of solutions in isocyanate prepolymers. The invention also is directed to a process for preparation of these new diisocyanates by the reaction of special diisocyanate starting materials and water and to their use as components for the production of polyurethanes.

Abstract: A carbamylbiuret-modified polyisocyanate of the formula: ##STR1## wherein n is an integer of from about 1 to about 20; R is a divalent radical containing from about 1 to about 18 carbon atoms; and Y is a divalent radical defined hereinbelow. The compounds of the invention are useful for preparing urethane-based microcellular foams and elastomers.

Abstract: A reaction product of a fatty acid ester and an organic polyisocyanate is included in a foamable reaction mixture containing an organic polyisocyanate to provide a molded product which can be removed from a mold whose surface has not been coated with conventional mold release agents.

Abstract: Organic amides, solutions of polymers thereof, which polymers are subject to hydrolysis and degradation in the presence of amines, and polymers isolated therefrom are stabilized by the presence of aromatic sulfonic acid esters of aliphatic, arylaliphatic and alicyclic alcohols and polyols.

Abstract: A reaction product of a fatty acid ester and an organic polyisocyanate is included in a foamable reaction mixture containing an organic polyisocyanate to provide a molded product which can be removed from a mold whose surface has not been coated with conventional mold release agents.

Abstract: Highly stable liquid 4,4'-diphenylmethane diisocyanate (MDI) containing MDI-carbodiimide adducts are prepared by heating MDI at a temperature of from 180.degree. C. to 250.degree. C. for a period of from one hour to ten hours in the presence of tris(chloromethyl)phosphine oxide and thereafter equilibrating the adduct formation. Equilibration can occur by any of several methods, i.e., by cooling the composition to a temperature of from 60.degree. C. to 90.degree. C. within twenty minutes, maintaining the composition at this temperature for a period of from one hour to four hours and thereafter cooling the composition to room temperature or by cooling the composition to a temperature less than 100.degree. C. within twenty minutes, further cooling to room temperature, and maintaining the composition at room temperature for one week to two weeks. The resulting compositions have very low sediment contents and are particularly useful in the preparation of microcellular polyurethane foams.

Abstract: The instant invention is directed to a process for the production of inorganic-organic synthetic materials having high strength, elasticity, dimensional stability under heat, and flame resistance, consisting of a polymer-polysilicic acid gel composite material in the form of a solid/solid xerosol, said process comprising mixing(a) an organic polyisocyanate,(b) an aqueous basic solution and/or an aqueous basic suspension having an inorganic solid content of from 20 to 80% by weight, preferably from 30 to 70% by weight,(c) an organic compound containing at least one isocyanate reactive hydrogen atom and at least one non-ionic-hydrophilic group and(d) optionally catalysts and other additivesand leaving the resulting mixture to react, characterized in that components (a) and (b), optionally with the addition of part or all of component (d) are first mixed together to form a stable primary dispersion and thereafter component (c), optionally with the addition of all or part of component (d), is added to form the fi

Abstract: Stable, liquid polyisocyanate compositions are prepared by reacting a polyisocyanate or a mixture of polyisocyanates and halogen-containing carboxylic acids. The polyisocyanates hereof are used to prepare polyurethanes, polyisocyanurates, poly(isocyanurate-urethane) and the like. These isocyanates can be used in foam formation, films, fibers, coating solutions, elastomers and the like.

Abstract: The instant invention is directed to a process for the preparation of modified polyisocyanates which contain sulfonic acid alkyl ester groups and in which the isocyanate groups may be at least partly in the dimerized form, comprising: reacting isocyanatoaryl sulfonic acids having at least two isocyanate groups and wherein the isocyanate groups may be at least partly in the dimerized form, optionally as mixtures with mono and/or polyisocyanates which are free from sulfonic acid groups, with di- and/or tetrahydrofurans at 0.degree. to 190.degree. C., wherein the equivalent ratio of isocyanate groups, including any isocyanate groups present in the dimerized form, to sulfonic acid groups is greater than 1 and the equivalent ratio of di- and tetrahydrofuran groups to sulfonic acid groups is from 0.1:1 to 10:1.

Abstract: The instant invention is directed to a process for the preparation of modified polyisocyanates which contain sulfonic acid alkyl ester groups and in which the isocyanate groups may be at least partly in the dimerized form, comprising: reacting isocyanatoaryl sulfonic acids having at least two isocyanate groups and wherein the isocyanate groups may be at least partly in the dimerized form, optionally as mixtures with mono and/or polyisocyanates which are free from sulfonic acid groups, with lactones at 0.degree. to 190.degree. C., wherein at least one of said lactones is a 6 to 9 membered ring lactone and the equivalent ratio of isocyanate groups, including any isocyanate groups present in the dimerized form, to sulfonic acid groups is greater than 1 and the equivalent ratio of lactone groups to sulfonic acid groups is from 0.1:1 to 10:1.

Abstract: Mercury and copper ions may be removed very selectively from aqueous solutions by means of a metal-chelating resin consisting of a polymer produced by the condensation of a phenolic component comprising one or more phenols, formaldehyde, and a diamino component comprising one or more di-(secondary amino) compounds under neutral conditions. The resin is prepared by condensing approximately equimolar quantities of a phenolic component comprising one or more phenols, and a diamino component comprising one or more di-(secondary amino) compounds with approximately twice the molar quantity of formaldehyde under Mannich reaction conditions.

Abstract: A hydrophilic foam is produced by mixing an isocyanate terminated branched polyethylene polyol with a polyester prepolymer and water. The foam may be used to impregnate fabrics, e.g., non-wovens, to produce reinforced sheets of foam of high absorbency and markedly improved abrasion resistance. Preferred polyesters are condensation products of adipic acid plus one or more alkanediols or a polylactone. Other prepolymers may also be included in the mix undergoing foaming, along with conventional additives.

Abstract: The present invention relates to a process for the preparation of polyisocyanates having biuret groups by reaction of excess quantities of organic polyisocyanates with compounds which react with isocyanate groups to form biuret groups, characterized in that the organic polyisocyanates are reacted with a mixture of water and at least one aliphatic, cycloaliphatic or araliphatic monoamine or polyamine.

Abstract: Covers a diisocyanate having the following structural formula: ##STR1## WHERE X IS AN AVERAGE NUMBER RANGING FROM ABOUT 6 TO 50, AND Y AND Z ARE AVERAGE NUMBERS RANGING FROM ABOUT 1 TO ABOUT 20, WITH THE SUM OF Y AND Z BEING FROM ABOUT 6 TO ABOUT 40. Also covers a method of preparing said diisocyanate.

Abstract: The instant invention is directed to a process for the production of inorganic-organic resins, by reaction of an organic polyisocyanate with aqueous basic solutions having an inorganic solid content of from 20 to 80% by weight in the presence of catalysts and optionally other additives, characterized in that the organic polyisocyanate and the aqueous basic solution are used in a proportion by weight of between 80:20 and 10:90 parts by weight and that organic ammonium compounds are used as catalysts.

Abstract: The instant invention is directed to a novel process for the production of inorganic/organic plastic materials and the resultant products. The process generally comprises reacting an aqueous alkali metal silicate solution with a liquid organic polyisocyanate having a viscosity at 25.degree. C of at least about 400 cP. Preferably, the process is utilized to produce high quality, lightweight foams having excellent physical properties.

Abstract: The present invention relates to a process for the preparation of polyisocyanates having biuret groups by reaction of excess quantities of organic polyisocyanates with compounds which react with isocyanate groups to form biuret groups, characterized in that the organic polyisocyanates are reacted with a mixture of water and at least one aliphatic, cycloaliphatic or araliphatic monoamine or polyamine.

Abstract: This invention relates to a process for the manufacture of an organo-metallate polymere which comprises reacting in a liquid phase a metallate with a pseudohalide compound and/or other polymerizable compound and allowing the reaction to proceed to completion.

Abstract: The instant invention relates to hydrophobic inorganic-organic lightweight foams produced from aqueous suspensions of finely divided water-insoluble inorganic materials and polyisocyanates. More particularly, the invention relates to a process for the production of highly filled, hydrophobic, lightweight polyurea foams comprising reacting(a) liquid, water insoluble polyisocyanates free from ionic groups, having viscosities of more than 200 cP at 25.degree. C. and having isocyanate functionalities of greater than 2.1, with(b) an aqueous suspension of inorganic filler, said suspension having a solids content of from 30 to 80 percent by weight and having a pH value of above 8, at least 50 percent by weight of the suspended fillers having a particle size of less than 50 microns,(c) in the presence of the foam stabilizer of the polyether/polysiloxane type and in the presence of a tertiary amine catalyst,The weight ratio of components (b) to component (a) being better 1:2 and 6:1.

Abstract: Cellular polymeric solids are made by mixing an acidulous or acidic polymerizable medium that is polymerizable and/or cross-linkable by a free radical mechanism (e.g. an unsaturated polyester) with an effective amount of two or more acid sensitive mono- or poly-azo compounds containing the group: ##STR1## wherein Y is an acid sensitive group (e.g.

Abstract: A novel cocatalyst combination for the trimerization of polyisocyanates to polyisocyanurates is disclosed. The catalyst combination comprises: (a) alkali metal glycine salts, (b) hydroxyalkyltrialkylammonium carboxylate salts, and (c) alkali metal salts selected from the group consisting of (i) alkali metal salts of N-phenyl aliphatic amides, and (ii) alkali metal salts of aliphatic carboxylic acids. The use of the cocatalyst combination provides for the facile formation of polyisocyanurate foam laminate boardstock which is characterized by good fire resistance and good physical properties.