Process for preparing a curable silylated polyurethane resin

A process for preparing a curable silylated polyurethane resin which comprises:

• a) silylating hydroxyl-terminated polyurethane polymer obtained from the reaction of polyol with di-isocyanate and/or polyisocyanate and optionally containing residual di-isocyanate and/or polyisocyanate with isocyanatosilane under anhydrous conditions to provide silylated polyurethane possessing residual hydroxyl groups and containing residual isocyanate selected from the group consisting of di-isocyanate, polyisocyanate and isocyanatosilane:
• and,
• b) scavenging residual isocyanate present in the silylated polyurethane with at least one isocyanate-reactive scavenging agent to provide silylated polyurethane resin of reduced isocyanate content,
• the silylated polyurethane resin of reduced isocyanate content resulting from step (b) possessing a viscosity following aging which is less than that of the isocyanate-containing silylated polyurethane resin resulting from step (a) following the same conditions of aging.