Process for producing polyurethane elastomer and composition as starting material therefor

Claim 1

A process for producing a non-cellular or microcellular polyurethane elastomer by reaction injection molding by using a high molecular weight active hydrogen compound component (A), a chain extender component (B) and a polyisocyanate compound component (C) as starting materials, wherein the component (A) is used in an amount of from 55 to 95% by weight based on the total amount by weight of the components (A and (B), the component (B) is used in an amount of from 5 to 45% by weight based on the total amount by weight of the components (A) and (B), and the component (C) is used in an amount of from 0.8 to 1.3 times in equivalent relative to the total equivalent of the components (A) and (B), and wherein (I) said high molecular weight active hydrogen compound component (A) comprises (1) at least one polyoxyalkylene polyol (a-1) having an average molecular weight per hydroxyl group of from 800 to 4000 and an average number of hydroxyl groups per molecule of from 2 to 8 and containing at least 5% by weight of oxyethylene groups at the terminal portions of its molecules, (2) a high molecular weight amine (a-2) having from 2 to 8 active hydrogen containing groups selected from the group consisting of primary amino groups, secondary amino groups and hydroxyl groups, provided that at least one of the active hydrogen-containing groups is an amino group selected from the group consisting of primary amino groups and secondary amino groups, and an average molecular weight per active hydrogen-containing group of from 800 to 4000, and optionally (3) a high molecular weight polyol (a-3) other than the polyalkylene polyol (a-1), wherein the total number of the primary amino groups and the secondary amino groups is from 2 to 55% based on the total number of the active hydrogen-containing groups in the constituents (a-1), (a-2) and (a-3), and the constituent (a-3) is in an amount of from 0 to 30% by weight based on the total amount by weight of the constituents (a-1), (a-2) and (a-3); and (II) said chain extender component (B) comprises (1) a low molecular weight polyol (b-1) having from 2 to 4 hydroxyl groups and a molecular weight of at most 400, (2) at least one diamine (b-2) selected from aromatic and alicyclic compounds and having two primary amino groups and no amino group directly bonded to an aromatic ring, and optionally (3) a chain extender (b-3) other than the constituents (b-1) and (b-2), having from 2 to 4 active hydrogen-containing groups selected from the group consisting of primary amino groups, secondary amino groups and hydroxyl groups, and a molecular weight of at most 400, wherein the constituent (b-1) is in an amount of from 55 to 98% by weight based on the total amount by weight of the constituents (b-1), (b-2) and (b-3), the constituent (b-2) is in an amount of from 2 to 35% by weight based on the total amount by weight of the constituents (b-1), (b-2) and (b-3), and the constituent (b-3) is in an amount of from 0 to 40% by weight based on the total amount by weight of the constituents (b-1), (b-2) and (b-3).