The Dow Chemical Company

The Upjohn Co.

Nancy P Vespoli

Louis M Alberino

Dale F Regelman

James R Pritchard

Polyurethane-polyurea polymers are disclosed that are derived from the reaction injection molding of organic polyisocyanates, optional high molecular weight active hydrogen containing compounds and extender mixtures comprising (i) aromatic diamines wherein at least one of the positions ortho to each amine group is substituted by a lower alkyl group and (ii) bis(hydroxyalkyl)cycloalkanes. The improved polymers have excellent resistance to high temperature conditions.

Cyclohexanedimethanol/diamine mixtures as RIM extenders

Polyamide-polyurea containing polymers are disclosed that are derived from the reaction of (A) an organic polyisocyanate; (B) an organic compound having at least two active hydrogen containing groups; and (C) about 15 to about 160 parts per 100 parts of said (B) of a chain extender combination comprising (i) a particular enamine and (ii) an aromatic diamine and optionally (iii) an extender diol wherein the ratio of equivalents of (A) to total equivalents of (B) and (C) is within the range of about 0.90:1 to 1.10:1. The polymers find particular utility in the preparation of RIM parts having excellent physical properties. At the same time, the polymers are characterized by slower gel times than prior art aromatic diamine extended polymers thereby allowing the filling of larger molded parts.

Polyamide-polyurea polymers by the RIM process

An improved process for the reaction injection molding of high flexural modulus polyurea containing elastomers is disclosed. Elastomers of this type when prepared at the prior art molding temperatures are brittle and can shatter like glass while still in the mold. The same elastomers when molded at a temperature of from about 90.degree. to about 220.degree. C. are not at all brittle. These elastomers are also characterized by the other advantageous properties inherent in polyurea elastomers such as high tensile strength, high hardness, and good heat resistance. The improved RIM process finds particular utility in the preparation of auto parts such as panels, engine hoods, and the like.

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Guilford, CT, United States of America

Nancy P Vespoli