One-package heat curable aromatic polyurethane composition useful for joining substrates and as an in-mold coating comprising an isocyanate terminated prepolymer and a polyhydroxy compound

摘要

A one-package heat curable polyurethane composition, comprising an isocyanate terminated prepolymer liquid phase and a separate solid polyhydroxy compound phase insoluble in the prepolymer phase, and suitable for use as an adhesive. The liquid prepolymer phase comprises the reaction product of an aromatic polyisocyanate and a polyhydroxy compound. The separate insoluble solid polyhydroxy compound phase is dispersed or suspended throughout the liquid prepolymer phase and remains separate until heat cured. The ratio of OH groups in the solid polyhydroxy compound phase to NCO groups in the isocyanate terminated prepolymer liquid phase is less than 2:1. The one-package polyurethane adhesive composition can also be useful as an in-mold coating and an injection molding compound.