Process for making decorative automotive interior trim articles with integral in-mold coated polyurethane aromatic elastomer covering

A process for making a layered composite structure, said process comprising:

• precoating a microcrystalline wax mold releasing agent on a first mold surface, the first mold surface being heated to a first elevated temperature to melt and disperse the microcrystalline wax mold releasing agent;
• applying a water-dispersed composition onto the first mold surface, the water-dispersed composition comprising at least one light-stable aliphatic thermoplastic polyurethane containing at least one pendent functional group selected from the group consisting of hydroxyl and carboxyl functional groups, at least one desired coloring agent, and at least one light-stable, blocked, heat-activated diisocyanate;
• heating the first mold surface at a second elevated temperature during said step of applying a water-dispersed composition to thereby induce partial crosslinking of the light-stable aliphatic thermoplastic polyurethane with the blocked, heat-activated diisocyanate;
• substantially drying the water-dispersed composition while on the first mold surface by heating the first mold surface to a third elevated temperature to form an outer layer having an outer surface complementary in configuration to the first mold surface;
• and
• spraying a rapidly reacting composition containing at least one aromatic polyisocyanate and at least one polyol onto an inner surface of the outer layer while on the first mold surface heated at a fourth elevated temperature to form an inner layer which comprises a polyurethane elastomer crosslinked with the polyurethane of the outer layer via residual unreacted functional groups of the blocked, heat-activated diisocyanate and thereby forming the layered composite structure having interfacial chemical bonding between the inner surface of the outer layer and an adjacent surface of the inner layer.