Patent ID: 6448364
Filing Date: 2002-09-10
Classification: C08G

Abstract:
A process for the production of a polyurethane elastomer from a reaction mixture by the reaction injection molding wherein the reaction mixture comprises:(A) an isocyanate-reactive component containing at least two isocyanate-reactive groups, having a molecular weight of from 400 to 12,000, a functionality of from about 2 to about 8, and being capped with from about 13 to about 21% by weight (based on 100% by weight of the alkylene oxide groups) of ethylene oxide, wherein said isocyanate-reactive groups being selected from the group consisting of hydroxyl groups, amine groups, and mixtures thereof; (B) an isocyanate-reactive component comprising: (1) an isocyanate-reactive component containing at least two hydroxyl groups and having a molecular weight of from 62 to 399, and (2) an isocyanate-reactive component selected from the group consisting of: (a) an isocyanate-reactive tertiary amine polyether having a functionality of at least two and a molecular weight of 62 to 399 and corresponding to the general formula: R(NR1R2)m â€ƒwherein: R: represents a saturated or unsaturated C2-C8 aliphatic or C2-C8 aliphatic substituted with â€”OH, â€”SH, or â€”NHRa wherein Ra is a C1-C8 alkyl or C2-C8 alkenyl; saturated or unsaturated C5-C8 cycloaliphatic or C5-C8 cycloalliphatic substituted with C1-C8 alkyl, C2-C8 alkenyl, C1-C8 alkylene, â€”OH, â€”SH or â€”NHRa wherein Ra is C1-C8 alkyl or C2-C8 alkenyl; or five- or six-membered aromatic or heteraromatic optionally substituted with C1-C8 alkyl, C1-C8 alkoxy, halogen, cyano, nitro, C1-C8 alkylene, â€”OH, â€”SH, or â€”NHRa wherein Ra is C1-C8 alkyl or C2-C8 alkenyl; R1 and R2: each independently represent polyether groups terminated with isocyanate-reactive groups selected from â€”OH, â€”SH and â€”NHRb wherein Rb is a C1-C8 alkyl or C2-C8 alkenyl; and m: represents an integer of from 1 to 4; (b) at least one organic amine compound containing at least one amino group having a moderated reactivity toward the organic polyisocyanate, as indicated by a gel time exceeding about 5 seconds measured from the material initiation time at 25-40Â° C., and having a number average molecular weight of from 62 to 399, said organic amine being selected from the group consisting of: (1) a sterically hindered aromatic amine in which one or more aromatic ring substituents are situated ortho to the amino groups, (2) an aromatic amine other than amine (B)(2)(b)(1) in which at least one of the amine groups exhibits reduced reactivity due primarily to electronic effects rather than steric factors, (3) an aromatic or non-aromatic amine having secondary amine groups, (4) a non-aromatic amine having sterically hindered primary amine groups, and (5) mixtures thereof; (c) at least one aminoalcohol having a molecular weight of 62 to 399 and containing at least one amine group and at least one hydroxyl group, and (d) mixtures thereof; (C) potassium halide; (D) an internal mold release agent comprising: (1) from 1 to 10% by weight, based on the weight of said reaction mixture, of mixed esters comprise the reaction product of (a) aliphatic dicarboxylic acids, (b) aliphatic polyols, and (c) monocarboxylic acids with 12 to 30 carbon atoms in the molecule, â€ƒwherein said reaction product has an acid number of less than 25 and a hydroxyl number of less than 25; and (E) at least one catalyst; and (F) a polyisocyanate component selected from the group consisting of a diphenylmethane diisocyanate, a modified diphenylmethane diisocyanate, an NCO prepolymer formed from diphenylmethane diisocyanate, and mixtures thereof.