Resin-based compositions for slush molding and composite parts manufactured therefrom

A polyvinyl chloride (PVC)-based composition for slush molding, the PVC-based composition comprising:

• about 100 parts per hundred resin of one or more PVC homopolymers;
• about 30 parts per hundred resin to about 90 parts per hundred resin of a primary plasticizer comprising an adipate, phthalate, trimellitate, or a combination thereof;
• about 1 parts per hundred resin to about 20 parts per hundred resin of a secondary plasticizer comprising an oil-based material;
• about 1 parts per hundred resin to about 10 parts per hundred resin of a heat stabilizer comprising a zinc-containing compound and a barium-containing compound;
• about 0.1 parts per hundred resin to about 2 parts per hundred resin of a UV absorber comprising a benzotriazole, a benzophenone, benzoate, or a combination thereof;
• about 0.1 parts per hundred resin to about 2 parts per hundred resin of a hindered amine light stabilizer (HALS) comprising a piperidine compound;
• about 5 parts per hundred resin to about 15 parts per hundred resin of an absorbent powder comprising particles of a PVC homopolymer;
• and
• optionally about 0.5 parts per hundred resin to about 2 parts per hundred resin of a pigment.

A thermoplastic polyolefin (TPO)-based composition for forming a foam layer via slush molding, the TPO-based composition comprising, by weight:

• about 50% to about 90% of a base resin comprising an olefin-block copolymer and a polypropylene copolymer;
• about 0.1% to about 0.8% of a sulfur-free stabilizer additive;
• about 2% to about 6% of a hindered amine light stabilizer (HALS) comprising a piperidine compound;
• about 1% to about 3% of a heat stabilizer comprising a zinc-containing compound and a barium-containing compound;
• about 0.25% to about 5% of a foaming agent comprising an endothermic chemical foaming agent or an exothermic chemical foaming agent;
• and
• about 0.05% to about 0.5% of an activator comprising a zinc-containing compound,
• wherein, when the foaming agent is combined with the activator, the foaming agent is configured to decompose at temperatures greater than or equal to about 150 degrees Celsius to less than about 180 degrees Celsius to release gases of nitrogen, carbon monoxide, carbon dioxide, or combinations thereof.

A composite part comprising:

• a skin layer having a first side and an opposite second side, wherein the first side of the skin layer defines a Class A surface;
• and
• a foam layer formed in situ on the second side of the skin layer,
• wherein the skin layer and the foam layer each comprise a polymer of the same type and comprise at least one polymer of the same type or at least one polymer having a monomer unit of the same type, and
• wherein the skin layer and the foam layer are chemically bonded to each other along an interface therebetween without use of an adhesive.