Rubber composition containing a polymer nanoparticle
View Patent ↗Provided is a composition comprising a rubber and a polymer nano-particle comprising a poly(mono-vinyl aromatic) core and a poly(mono-vinyl aromatic-conjugated diene) surface layer, wherein the core of the polymeric nano-particle has a glass transition temperature (Tg) of between about 150° C. and about 600° C. Also provided is a composition comprising at least two (mono-vinyl aromatic-conjugated diene) copolymer rubbers and a polymeric nano-particle comprising a poly(mono-vinyl aromatic) core and a poly(mono-vinyl aromatic-conjugated diene) surface layer; wherein the core of the polymeric nano-particle has a glass transition temperature (Tg) of between about 150° C. and about 600° C., and the poly(mono-vinyl aromatic-conjugated diene) surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 50 percent and about 150 percent that of the mono-vinyl content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
1. A composition comprising:
(a) at least two (mono-vinyl aromatic-conjugated diene) copolymer rubbers, and
(b) a polymeric nano-particle comprising a poly(mono-vinyl aromatic) core and a poly(mono-vinyl aromatic-conjugated diene) surface layer;
wherein the core of the polymeric nano-particle has a glass transition temperature (Tg) of between about 150° C. and about 600° C., and
the poly(mono-vinyl aromatic-conjugated diene) surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 50 percent and about 150percent that of the mono-vinyl content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
2. The composition of claim 1 , wherein the surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 75 percent and 125 percent that of the mono-vinyl aromatic content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
3. The composition of claim 1 , wherein the surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 90 percent and 110 percent that of the mono-vinyl aromatic content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
4. The composition of claim 1 , wherein said poly(mono-vinyl aromatic) core comprises polystyrene, and said poly(mono-vinyl aromatic-conjugated diene) surface layer comprises a poly(styrene-butadiene).
5. The composition of claim 1 , wherein the polymeric nano-particle has a mean average diameter between about 5 and 200 nanometers.
6. The composition of claim 1 , wherein the polymeric nano-particle has a mean average diameter of between about 5 and 100 nanometers.
7. The composition of claim 1 , further comprising a low PCA processing oil having a polycyclic aromatic content of less than 3 percent by weight as determined by the IP346 method.
8. A tire comprising a tread, wherein said tread comprises:
(a) at least two (mono-vinyl aromatic-conjugated diene) copolymer rubbers, and
(b) a polymeric nano-particle comprising a poly(mono-vinyl aromatic) core and a poly(mono-vinyl aromatic-conjugated diene) surface layer,
wherein the core of the polymeric nano-particle has a glass transition temperature (Tg) of between about 150° C. and about 600° C., and
the poly(mono-vinvl aromatic-conjugated diene) surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 50 percent and about 150 percent that of the mono-vinyl content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
9. The tire of claim 8 , further comprising a low PCA processing oil having a polycyclic aromatic content of less than 3 percent by weight as determined by the IP346 method.
10. The tire of claim 8 , wherein said rubber comprises at least two (mono-vinyl aromatic-conjugated diene) copolymer rubbers, and the surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 50 percent and about 150 percent that of the mono-vinyl aromatic content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
11. The tire of claim 8 , wherein the surface layer of the polymeric nano-particle comprises a mono-vinyl aromatic content that is between about 75 percent and 125 percent that of the mono-vinyl aromatic content of one of the (mono-vinyl aromatic-conjugated diene) copolymer rubbers.
12. The tire of claim 8 , wherein said at least two (mono-vinyl aromatic-conjugated diene) copolymer rubbers are each styrene-butadiene copolymers.
13. The tire of claim 8 , wherein the wherein said poly(mono-vinyl aromatic) core comprises polystyrene, and said poly(mono-vinyl aromatic-conjugated diene) surface layer comprises a poly(styrene-butadiene).
14. The composition of claim 1 , wherein the core of the polymeric nano-particle has a Tg of between about 200° C. and about 400° C.
15. The composition of claim 1 , wherein the core of the polymeric nano-particle has a Tg of between about 250° C. and about 300° C.
16. The composition of claim 5 , wherein the polymeric nano-particle is present at a level between about 1 phr and about 50 phr.
17. The tire of claim 8 , wherein the core of the polymeric nano-particle has a Tg of between about 200° C. and about 400° C.
18. The tire of claim 8 , wherein the core of the polymeric nano-particle has a Tg of between about 250° C. and about 300° C.
19. The tire of claim 8 , wherein the polymeric nano-particle is present at a level between about 1 phr and about 50 phr.
20. The tire of claim 8 , wherein the polymeric nano-particle has a mean average diameter of between about 5 and 100 nanometers.
21. The composition of claim 1 , wherein the core is cross-linked with a multiple-vinyl aromatic cross-linking agent.
22. The tire of claim 8 , wherein the core is cross-linked with a multiple-vinyl aromatic cross-linking agent.