Decorative automotive interior trim articles with cast integral light stable covering and process for making the same

A process for making a panel structure mountable in an automobile vehicle to form a part of a vehicle interior thereof, the panel structure comprising a reinforcing substrate and a layered composite structure, the layered composite structure comprising an outer layer defining at least a portion of an at least partially exposed exterior surface of the panel structure and an inner layer, said process comprising the steps of:

• applying a first composition onto a first mold surface, said first 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, and at least one heat-activated crosslinking monomer or agent to form said outer layer of said layered composite structure;
• and
• casting a second composition comprising a thermoplastic polyurethane resin material having at least one ethylenically unsaturated bond in its backbone, at least one pendent hydroxyl group, or a combination thereof onto an inner surface of the outer layer while on the first mold surface to form said inner layer of said layered composite structure,
• whereby an interfacial chemical bond is formed between at least one of an unreacted functional group of said at least one light-stable aliphatic thermoplastic polyurethane and an unreacted functional group of said at least one heat activated crosslinking monomer or agent of said outer layer and at least one of said at least one ethylenically unsaturated bond and at least one pendent hydroxyl group of said inner layer.

A process for making a panel structure mountable in an automobile vehicle to form a part of a vehicle interior thereof, the panel structure comprising a reinforcing substrate and a layered composite structure, the layered composite structure comprising an outer layer defining at least a portion of an at least partially exposed exterior surface of the panel structure and an inner layer, said process comprising the steps of:

• providing a microcrystalline wax mold releasing agent on a first mold surface, the first mold surface being heated to a first temperature for melting and dispersing the microcrystalline wax mold releasing agent;
• applying a first composition onto the first mold surface containing the microcrystalline wax mold releasing agent dispersed thereon, first 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, and at least one heat-activated crosslinking agent, the first mold surface being heated to a second temperature for inducing at least a partial crosslinking of the light-stable aliphatic thermoplastic polyurethane with the heat-activated crosslinking agent;
• substantially drying the water-dispersed first composition while on the first mold surface by heating the first mold surface to a third temperature for forming the outer layer with an exterior surface;
• casting a second composition comprising a thermoplastic polyurethane resin material having at least one ethylenically unsaturated bond in its backbone, at least one pendent hydroxyl group, or a combination thereof onto an inner surface of the outer layer while on the first mold surface to form the inner layer, whereby an interfacial chemical bond is formed between at least one of an unreacted functional group of said at least one light-stable aliphatic thermoplastic polyurethane and an unreacted functional group of said at least one heat activated crosslinking monomer or agent of said outer layer and at least one of said at least one ethylenically unsaturated bond and at least one pendent hydroxyl group of said inner layer;
• and
• uniting the layered composite structure with the reinforcing substrate so that the reinforcing substrate reinforces the outer layer while retaining a touch, color, and configuration of the exposed portion.