Bayer Corporation

Bayer Materialscience, LLC

Bayer Polymers LLC

Brian R Suddaby

Neil H Nodelman

Karl W Haider

John P Forsythe

Ronald A Cageao

A Donald Meltzer

The present invention is directed to a process for preparing water-blown rigid polyurethane foams having at least an 80% closed-cell content which involves reacting a) at least one polyol mixture which is composed of (i) at least one polymer polyol; (ii) at least one polyol having a hydroxyl value within the range of from about 200 to about 800; and (iii) optionally, at least one polyol having a hydroxyl value within the range of from about 25 to about 115; with b) at least one polymeric isocyanate and/or a prepolymer thereof; in the presence of c) optionally, at least one catalyst; d) water; and e) optionally, at least one additive or auxiliary agent. The present invention is also directed to the closed-cell water blown rigid polyurethane foams produced by the process of the present invention. The invention is further directed to a polyurethane-foam forming mixture which is used to produce the water-blown rigid polyurethane foams of the present invention. Foams produced according to the present invention have reduced friability and acceptable adhesion to substrates as well as acceptable compressive strength.

Process for preparing closed-cell water-blown rigid polyurethane foams having improved mechanical properties

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

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Pittsburgh, PA, United States of America

Brian R Suddaby