Decorative automotive interior trim articles with cast integral light stable covering and process for making the same
An article including a panel structure mountable in an automobile vehicle to form a part of the vehicle interior thereof, and a process for making the same are disclosed. According to this process, an outer layer defining at least a portion of the exposed exterior surface of the structure is prepared by applying a first composition containing a thermoplastic polyurethane and a heat-activated crosslinking agent onto a mold surface and thereafter drying the composition. Next, a second composition comprising (i) a poly(vinyl chloride) resin and at least one plasticizer and/or (ii) a thermoplastic polyurethane resin material is gelled onto an inner surface of the outer layer while on the outer layer is retained on the mold surface. The gelled composition is then fused to form an inner layer interfacially chemically bonded to the outer layer. The layered composite structure is united with the reinforcing substrate so that the reinforcing substrate serves to reinforce the outer layer. The exposed exterior surface of the panel structure simulates the appearance and feel of authentic leather, while the inner layer and an optional semi-rigid polyurethane cellular foam intermediate layer provide a compressing feel to the exposed portion.
1. A panel structure mountable in a vehicle to form a part of a vehicle interior thereof, the panel structure having an exterior surface, at least a portion of which is exposed to the vehicle interior, and an interior surface, said panel structure comprising:
a reinforcing substrate;
a layered composite structure comprising an outer layer defining at least a portion of said exterior surface of the panel structure and an inner layer, said layered composite structure being united to a surface of said reinforcing substrate;
said outer layer comprising at least one light-stable aliphatic thermoplastic polyurethane and at least one heat-activated crosslinking agent;
said inner layer being adjacent to said outer layer such that said inner layer has an outer surface adjacent an inner surface of said outer layer, said inner layer comprising a polyvinyl chloride and a plasticizer,
wherein an interfacial chemical bond is formed between at least one of a pendent 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 agent of said outer layer and at least one pendent functional group of said plasticizer of said inner layer.
2. A panel structure as defined in claim 1 wherein the pendent functional group of said at least one light-stable aliphatic thermoplastic polyurethane is at least one of a hydroxyl and a carboxyl group.
3. A panel structure as defined in claim 1 wherein the pendent functional group of said plasticizer is at least one of a hydroxyl and a carboxyl group.
4. A panel structure as defined in claim 1 , wherein the heat-activated crosslinking agent is carbodiimide or aziridine.
5. A panel structure as defined in claim 1 , wherein said outer layer further comprises at least one coloring agent.
6. A panel structure as defined in claim 1 , further comprising a relatively rigid or semi-rigid polyurethane cellular foam interposed between said layered composite structure and said reinforcing substrate that adheres said layered composite structure to said reinforcing substrate.
7. A panel structure as defined in claim 6 , wherein said outer layer has a thickness in a range of from about 1.0 mils to about 1.5 mils.
8. A panel structure as defined in claim 6 , wherein said inner layer has a thickness in a range of from about 40 mils to about 60 mils.
9. A panel structure as defined in claim 6 , wherein said panel structure is a door panel.
10. A panel structure as defined in claim 6 , wherein said panel structure is an instrument panel.
11. A panel structure as defined in claim 1 , wherein at least a portion of an outer surface of the outer layer has a desired touch, color, and grain-like configuration of the panel structure.