摘要:
Homogeneous storable mixtures containing small quantities of a potassium halide, having a high mixed hydroxyl number or mixed hydroxyl/amine number and an average functionality of at least 2.0 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 and (b) a low molecular weight polyol which is not completely miscible with (a) wherein these mixtures are reacted with a prepolymer or a polyisocyanate to produce shrink stable thermal break urethanes having good adhesion to substrate properties and wherein the use of such mixtures increases processing flexibility without detrimentally affecting the physical properties of the thermal break urethanes produced.
摘要:
This invention relates to a process for the production of polyurethane/urea moldings which exhibit both high flexural modulus and high impact strength. The process comprises reaction injection molding of a reaction mixture in the presence of a catalyst via the one-shot process. The isocyanate component of this invention is a prepolymer of methylenebis(cyclohexyl isocyanate) having an NCO content of 12-27%, an average isocyanate functionality of less than 2.3, a monomer content of greater than about 25% by weight, and containing urethane or urea groups. The isocyanate-reactive blend comprises a high molecular weight polyether polyol and a low molecular weight chain extender, wherein the isocyanate-reactive blend has an OH:NH equivalent ratio of from 1:1 to 15:1. This invention also relates to the polyurethane/urea molded article produced by the above process.
摘要:
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.
摘要:
Energy absorbing flexible foams can be produced by reacting an isocyanate with a first polyol, prepared at least in part by an active double metal cyanide catalyst and a second polyether polyol is prepared at least in part by a basic or acidic catalyst.
摘要:
Increases in reactivity of acidic containing RIM systems are reduced by inclusion of a catalyst system of a zinc-containing compound, a non-zinc containing metal compound and a tertiary amine.
摘要:
The present invention is directed to a process for producing a molded product comprising(A) reacting:(i) an organic polyisocyanate having an isocyanate group content of from 5 to 45% by weight, preferably from 15 to 35% by weight, and most preferably from 20 to 35% by weight, prepared by reacting:(a) an organic di- and/or polyisocyanate, and(b) an active hydrogen containing fatty acid ester prepared by reacting an alcohol or polyol with an aliphatic, saturated or unsaturated fatty acid, said ester being characterized in that at least one aliphatic acid which contains more than 8 carbon atoms is built into the molecule, said ester further characterized as having an acid number of from 0 to 100 and a hydroxyl number of from 0 to 150 with at least one of said numbers being greater than zero, said ester having an average molecular weight of from 500 to 5000,(ii) an isocyanate reactive component comprising:(a) from about 0.5 to about 10% by weight based on the weight of components (ii)(b) and (ii)(c), of a zinc carboxylate containing from 8 to 24 carbon atoms per carboxylate group,(b) from about 0.3 to 100% by weight, preferably from 0.5 to 95% by weight, more preferably from 5 to 45% by weight, and most preferably from 10 to 35% by weight, based on the weight of components (ii)(b) and (ii)(c), of a compatibilizer which compatibilizes said carboxylate in component (ii), and(c) 0 to about 99.5% by weight, preferably from 5 to 99.5% by weight, more preferably from 55 to 95% by weight, and most preferably from 65 to 90% by weight, based on the weight of components (ii)(b), and (ii)(c), of at least one active hydrogen containing compound other than said compatibilizer,at an isocyanate index of from about 90 to about 400 and preferably from about 95 to about 115, in a closed mold,(B) allowing the components to react, and(C) removing the product from the mold.
摘要:
The present invention is directed to a polyester polyol having a molecular weight between about 850 and 2000, a functionality of about 5 to 9 and an OH number of about 200 to 350, based on 100% solids, which is prepared by reacting(a) an acid component based on at least one polyfunctional cycloaliphatic or aromatic carboxylic acid, anhydride or ester and optionally up to about 50 percent by weight of at least one acyclic, polyfunctional carboxylic acid and(b) a hydroxyl component containing at least a portion of at least one polyol having a functionality of at least 3.The present invention is also directed to a process for preparing these polyester polyols by reacting the above components and is further directed to the use of these polyester polyols in combination with organic polyisocyanates for the production of polyurethanes, particularly polyurethane coatings.
摘要:
The present invention is directed to a process for the production of polyurethane moldings by reacting a reaction mixture comprising(a) an organic polyisocyanate(b) a compatible polyol blend comprising(i) at least one polyether polyol having an hydroxyl functionality of from 2 to 8, and a molecular weight of from 350 to below 1800, and(ii) at least one hydroxyl functional organic material containing from 2 to 8 hydroxyl groups and having a molecular weight below 350, components (i) and (ii) being used in a weight ratio of component (b)(i) to (b)(ii) of from about 10:1 to about 1:10, and(iii) no more than 45% by weight based on the weight of component (b) of an active hydrogen containing compound having a molecular weight of 1800 or more,said reaction mixture being processed as a one-shot system by the RIM process at an isocyanate index of from about 70 to about 130.
摘要:
This invention relates to a process for the preparation of a flexible foam. This process comprising reacting a liquid, storage stable, allophanate-modified polyisocyanate having an NCO group content of about 20 to about 42%, with an isocyanate-reactive component, in the presence of a blowing agent and at least one catalyst, wherein the relative amounts of the polyisocyanate and the isocyanate-reactive component are such that the NCO index if from about 70 to about 130.
摘要:
A high solids, chip resistant, sprayable polyurethane coating composition comprising the reaction mixture of a ketoxime-blocked polyisocyanate and a cyclohexanedicarboxylic acid-based polyester polyol, is disclosed. The composition is characterized by its relatively low viscosity and the resulting coating is characterized by its low volatile organic content.