Pneumatic tire with tread
View Patent ↗The present invention is directed to a pneumatic tire comprising a ground contacting tread, the tread comprising a rubber composition comprising from 30 to 70 parts by weight, per 100 parts by weight of s first elastomer (phr) having a glass transition temperature Tg ranging from about −40° C. to about −10° C. and a solubility parameter ranging from about 4.1 MPa 1/2 to about 4.5 MPa 1/2 ; from 70 to 30 phr of a second elastomer having a Tg ranging from about −105° C. to about −30° C. and a solubility parameter ranging from about 3.7 MPa 1/2 to about 4.1 MPa 1/2 ; from 1 to 40 phr of a first plasticizer having a solubility parameter ranging from 3.4 MPa 1/2 to 3.8 MPa 1/2 ; from 1 to 20 phr of a second plasticizer having a solubility parameter ranging from 4.3 MPa 1/2 to 4.7 MPa 1/2 ; and from 30 to 150 phr of silica.
1. A pneumatic tire comprising a ground contacting tread, the tread comprising a rubber composition comprising
from 30 to 70 parts by weight, per 100 parts by weight of elastomer (phr), of a styrene-butadiene rubber having a bound styrene of at least 36 percent by weight;
from 70 to 30 phr of a rubber selected from polybutadiene rubber and polyisoprene rubber;
from 1 to 40 phr of a polyalphaolefin having a glass transition temperature Tg below −60° C.;
from 1 to 20 phr of a resin derived from styrene and alphamethylstyrene having a glass transition temperature Tg ranging from 20° C. to 100° C.; and
from 30 to 150 phr of silica;
wherein the styrene-butadiene rubber is viscoelastically incompatible with the rubber selected from polybutadiene rubber and polyisoprene rubber.
2. The pneumatic tire of claim 1 , wherein the polyalphaolefin is selected from the group consisting of polymers of butene, pentene, hexane, heptene, octene, nonene, decene, undodecene, and dodecene.
3. The pneumatic tire of claim 1 , wherein the polyalphaolefin is a polymer of 1-decene.
4. A pneumatic tire comprising a ground contacting tread, the tread comprising a rubber composition comprising
from 30 to 70 parts by weight, per 100 parts by weight of s first elastomer (phr) having a glass transition temperature Tg ranging from about −40° C. to about −10° C. and a solubility parameter ranging from about 4.1 MPa 1/2 to about 4.5 MPa 1/2 ;
from 70 to 30 phr of a second elastomer having a Tg ranging from about −105° C. to about −30° C. and a solubility parameter ranging from about 3.7 MPa 1/2 to about 4.1 MPa 1/2 ;
from 1 to 40 phr of a first plasticizer having a solubility parameter ranging from 3.4 MPa 1/2 to 3.8 MPa 1/2 ;
from 1 to 20 phr of a second plasticizer having a solubility parameter ranging from 4.3 MPa 1/2 to 4.7 MPa 1/2 ; and
from 30 to 150 phr of silica
wherein the first elastomer is viscoelastically incompatible with the second elastomer.
5. The pneumatic tire of claim 4 , wherein the first elastomer is a styrene-butadiene rubber having a bound styrene content of at least 36 percent by weight.
6. The pneumatic tire of claim 4 , wherein the second elastomer is selected from polybutadiene and polyisoprene.
7. The pneumatic tire of claim 4 , wherein the second plasticizer is a resin derived from styrene and alphamethylstyrene having a styrene/alphamethylstyrene ratio ranging from 0.4 to 1.5; a molecular weight ratio Mw/Mn ranging from 1.5 to 2.5, and a glass transition temperature Tg ranging from 30° C. to 100° C.
8. The pneumatic tire of claim 4 , wherein the first plasticizer is a polyalphaolefin.
9. The pneumatic tire of claim 8 , wherein the polyalphaolefin is selected from the group consisting of polymers of butene, pentene, hexane, heptene, octene, nonene, decene, undodecene, and dodecene.
10. The pneumatic tire of claim 8 , wherein the polyalphaolefin is a polymer of 1-decene.