Thermoplastic polyurethane compounds exhibiting stain resistance and enhanced UV stability
AssigneeAvient Corporation
InventorJiren Gu
Life of this patent
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Abstract
Thermoplastic articles are molded from thermoplastic polyurethane compounds including blends of aromatic polycaprolactone thermoplastic polyurethane and aliphatic polycaprolactone thermoplastic polyurethane. The thermoplastic articles can have enhanced stability against exposure to ultraviolet (UV) light relative to thermoplastic articles molded from thermoplastic polyurethane compounds including only aromatic polycaprolactone thermoplastic polyurethane as the thermoplastic polyurethane component. Additionally, the thermoplastic articles can have good stain resistance, good clarity (i.e., low haze), and other desirable properties.
Claims15
A thermoplastic article molded from a thermoplastic polyurethane compound, the thermoplastic polyurethane compound comprising:
- 100 parts by weight of thermoplastic polyurethane selected from blends of aromatic polycaprolactone thermoplastic polyurethane and aliphatic polycaprolactone thermoplastic polyurethane, wherein at least about 50 parts by weight is the aromatic polycaprolactone thermoplastic polyurethane,
- a secondary polymer in an amount of not more than 200 parts by weight, wherein the secondary polymer is selected from thermoplastic vulcanizates, polyolefin elastomers, copolyesters, and combinations thereof
- wherein the thermoplastic article, after subjected to QUV Test, achieves a Yellow Index of less than about 8.5:
- wherein the thermoplastic article is a protective case or portion thereof for a handheld electronic device.
An overmolded article comprising:
- (a) an overmold portion comprising a thermoplastic polyurethane compound, the thermoplastic polyurethane compound comprising:
- 100 parts by weight of thermoplastic polyurethane selected from blends of aromatic polycaprolactone thermoplastic polyurethane and aliphatic polycaprolactone thermoplastic polyurethane, wherein at least about 50 parts by weight is the aromatic polycaprolactone thermoplastic polyurethane,
- a secondary polymer in an amount of not more than 200 parts by weight, wherein the secondary polymer is selected from thermoplastic vulcanizates, polyolefin elastomers, copolyesters, and combinations thereof;
- and
- (b) a substrate portion molded from a thermoplastic resin compound;
- wherein the overmold portion is bonded onto the substrate portion at a bond interface, and the bond interface is free of adhesive;
- wherein the overmold portion, after subjected to QUV Test, achieves a Yellow Index of less than about 8.5;
- and
- wherein the overmolded article is a protective case or portion thereof for a handheld electronic device.
A method of improving stability against ultraviolet light exposure by a thermoplastic articlemolded from a thermoplastic polyurethane compound including 100 parts by weight of thermoplastic polyurethane, the method comprising the step of selecting the thermoplastic polyurethane from blends of aromatic polycaprolactone thermoplastic polyurethane and aliphatic polycaprolactone thermoplastic polyurethane, wherein at least about 50 parts by weight is the aromatic polycaprolactone thermoplastic polyurethane, and a secondary polymer in an amount of not more than 200 parts by weight, wherein the secondary polymer is selected from thermoplastic vulcanizates, polyolefin elastomers, copolyesters, and combinations thereof;
- and
- wherein the thermoplastic article, after subjected to QUV Test, achieves Yellow Index of less than about 8.5;
- and
- wherein the thermoplastic article is a protective case or portion thereof for a handheld electronic device.
Dependencies are inferred from the claim text.