Patent ID: 6737471
Filing Date: 2004-05-18
Classification: C08G

Abstract:
A polyurethane elastomer comprising the product of the reaction of:a) at least one member selected from the group consisting of diisocyanate and polyisocyanate; b) at least one polyester polyol having an OH number of 20 to 280 and a functionality of 1.8 to 2.4, and optionally; c) at least one member selected from the group consisting of polyether polyol and polyether ester polyol, each having an OH number of 10 to 149 and a functionality of 2 to 8; and d) optionally at least one member selected from the group consisting of (i) chain extenders having molecular weights lower than 800, and (ii) crosslinking agents having OH numbers of 150 to 1870, in the presence ofe) at least one amine catalyst, f) at least one member selected from the group consisting of (i) an ester of a monobasic carboxylic acid, and (ii) an ester of a polybasic carboxylic acid, the (first) dissociation constant (pK) of each being 0.5 to 4, said ester of said polybasic carboxylic acid (ii) containing a residue of a polybasic carboxylic acid selected from the group consisting of oxalic acid, malonic acid, maleic acid, fumaric acid, citric acid, phthalic acid, trimellitic acid and pyromellitic acid, and said ester of said polybasic carboxylic acid (ii) containing at least one residue of an alcohol selected from the group consisting of methanol, ethanol n-propanol, iso-propanol, n-butanol, iso-butanol, tert.-butanol and phenol, g) optionally a foaming agent, and h) optionally at least one additive selected from the group consisting of emulsifiers, foam stabilizers, cell-size regulators, flame retardants, nucleating agents, antioxidants, internal lubricants, demolding agents, colorants, dispersing agents, pigments, reaction retarders, aging stabilizers, plasticizers, fungicides and antibacteria agents, wherein the maximum ratio of the number of ester groups of f) to the number of amino groups of e) is 1.0.