Thermoplastic elastomers with silky feel
View Patent ↗A thermoplastic elastomer compound is blended from styrenic block copolymer, thermoplastic vulcanizate, thermoplastic polyurethane, a compatibilizer, and a masterbatch containing silicone, which is added to provide a qualitative silky feel on surfaces of plastic articles made from the compound.
1. A thermoplastic elastomer compound, comprising
(a) styrenic block copolymer selected from the group consisting of styrene-ethylene-butylene-styrene and styrene-ethylene-ethylene-propylene-styrene;
(b) thermoplastic vulcanizate in an amount of about 3 to about 6 weight percent of the thermoplastic elastomer compound, wherein the thermoplastic vulcanizate is a pre-mixed blend of a continuous phase of polyolefin and a discontinuous phase of vulcanized rubber;
(c) thermoplastic polyurethane;
(d) compatibilizer to assist in blending of the styrenic block copolymer with the thermoplastic polyurethane; and
(e) siloxane polymer in an amount of about 0.1 to about 1.0 weight percent of the thermoplastic elastomer compound.
2. The thermoplastic elastomer compound of claim 1 , wherein the siloxane polymer is in a masterbatch having a polyolefin carrier.
3. The thermoplastic elastomer compound of claim 1 , wherein the styrenic block copolymer has a weight average molecular weight of between about 70,000 and about 360,000.
4. The thermoplastic elastomer compound of claim 1 , wherein the polyolefin is polypropylene and the vulcanized rubber is crosslinked ethylene-propylene-diene rubber.
5. The thermoplastic elastomer compound of claim 1 , wherein the compatibilizer is maleic anhydride grafted styrene-ethylene-butylene-styrene.
6. The thermoplastic elastomer compound of claim 1 , further comprising plasticizer oil.
7. The thermoplastic elastomer compound of claim 1 , further comprising filler.
8. The thermoplastic elastomer compound of claim 7 , further comprising an additive selected from the group consisting of adhesion promoters; biocides; anti-fogging agents; anti-static agents; bonding, blowing and foaming agents; dispersants; flame retardants and smoke suppresants; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; oils and plasticizers; processing aids; release agents; silanes, titanates and zirconates; slip and anti-blocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of them.
9. The thermoplastic elastomer compound of claim 1 , wherein ingredients by weight percent of the thermoplastic elastomer compound are
Styrenic Block Copolymer Resin
1-30;
Compatibilizer
0.1-10;
Thermoplastic Vulcanizate Resin
3-6;
Thermoplastic Polyurethane Resin
10-90;
Silicone
0.1-1.0;
Optional Plasticizer Oil
0-40;
Optional Filler
0-30;
and
Optional Additives
0-10.
10. A plastic article formed from the thermoplastic elastomer compound of claim 1 .
11. The plastic article of claim 10 in the form of a molded article, an extruded article, or a calendered article.
12. The plastic article of claim 10 , in the form of a protective cover for handheld consumer electronics items.
13. The plastic article of claim 10 , in the form of an electronic console, controlling device, gaming console, desk computer, or laptop computer.
14. The plastic article of claim 10 , wherein the plastic article has an outer surface having a silky feel to a touch of a human hand.
15. A thermoplastic elastomer compound comprising:
(a) styrenic block copolymer selected from the group consisting of styrene-ethylene-butylene-styrene and styrene-ethylene-ethylene-propylene-styrene;
(b) thermoplastic vulcanizate in an amount of about 3 to about 6 weight percent of the thermoplastic elastomer compound;
(c) thermoplastic polyurethane;
(d) compatibilizer to assist in blending of the styrenic block copolymer with the thermoplastic polyurethane; and
(e) siloxane polymer in an amount of about 0.1 to about 1.0 weight percent of the thermoplastic elastomer compound;
wherein the thermoplastic elastomer compound has a silky feel to a touch of a human hand.
16. A plastic article formed from a thermoplastic elastomer compound, the thermoplastic elastomer compound comprising:
(a) styrenic block copolymer selected from the group consisting of styrene-ethylene-butylene-styrene and styrene-ethylene-ethylene-propylene-styrene;
(b) thermoplastic vulcanizate in an amount of about 3 to about 6 weight percent of the thermoplastic elastomer compound;
(c) thermoplastic polyurethane;
(d) compatibilizer to assist in blending of the styrenic block copolymer with the thermoplastic polyurethane; and
(e) siloxane polymer in an amount of about 0.1 to about 1.0 weight percent of the thermoplastic elastomer compound;
wherein the plastic article has an outer surface having a silky feel to a touch of a human hand.