Bayer Corporation

Bayer Aktiengesellschaft

A Donald Meltzer

David D Steppan

Neil H Nodelman

Jan L Clatty

Eduard Mayer

Albert Magnotta

Ronald A Cageao

Brian R Suddaby

The present invention is directed to a method of forming a gasket around a substrate from a novel polyurethane/urea composition via the RIM process. Window gaskets may be produced by this method. These novel polyurethane/urea compositions comprise the reaction product of a (cyclo)aliphatic polyisocyanate having a viscosity of less than about 25,000 mPa.multidot.s at 25.degree. C. and a NCO functionality of 2.0 to 4.0 with an isocyanate-reactive component comprising b1) a relatively high molecular weight organic compound containing hydroxyl groups, amine groups, or mixtures thereof; and b2) a low molecular weight chain extender selected from the group consisting of diols, primary amines, secondary amines, aminoalcohols, and mixtures thereof; in the presence of a catalyst. The isocyanate and isocyanate-reactive components are selected such that the crosslinking density of the resultant polyurethane/urea composition is at least 0.3 moles/kg. It is also possible that the isocyanate-reactive component comprises b3) a low molecular weight chain terminator, and/or b4) a low molecular weight crosslinking agent. When either or both of these components are included in the isocyanate-reactive component, A, b1), b2), and/or b3) and/or b4) must be selected such that the crosslinking density of the resultant polyurethane/urea composition is at least 0.3 moles/kg.

Method of producing gaskets from polyurethane/urea compositions and

This invention relates to a process for the production of polyurethane/urea moldings from a reaction injection molding process by processing the reaction mixture consisting of a diisocyanate and an isocyanate-reactive component via the one-shot process at an isocyanate index of about 80 to 130. The diisocyanate is an unmodified cycloaliphatic diisocyanate. The isocyanate-reactive component consists of 1) at least one polyol having functional groups which are hydroxyl groups, amine groups, or mixtures of hydroxyl groups and amine groups such that the equivalent ratio of hydroxyl groups to amine groups is from 0:1 to 1:1, and 2) at least one chain extender which is selected from diols, triols, primary aliphatic amines, secondary aliphatic amines, aminoalcohols and mixtures thereof. The equivalent ratio of hydroxyl groups to amine groups in the chain extender component is from 1:2 to 10:1. A catalyst capable of catalyzing the reaction between isocyanate groups and isocyanate-reactive groups is also present in the reaction mixture.

Cycloaliphatic diisocyanate based rim elastomers

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.

High modulus, high impact polyurethane/polyurea RIM

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Brecksville, OH, United States of America

A Donald Meltzer