Granted Patent B2

US 12,371,552 · App. 17/614,946 · Granted Jul 29, 2025

Inventors: Dennis C. Boley (Mogadore, OH); Kenny L. Howman (Ashland, OH); Benjamin C. Galizio (Munroe Falls, OH); Jamie L. Whyte (Kent, OH); Jessica L. Placke (Rocky River, OH); Anthony M. Unger (New Albany, OH)

Assignee: Bridgestone Americas Tire Operations, LLC

C08L9/00C08L2205/035

Abstract

Claims (56)

1. A tire tread rubber composition made of ingredients comprising:

a. 100 parts of an elastomer component comprising:

i. 70-85 parts of polybutadiene having a cis bond content of at least 95% and a Tg of −101 to −110° C.,

ii. 10-25 parts of at least one styrene-butadiene rubber functionalized with a silica-reactive functional group and having a Tg of −40 to −75° C.,

iii. 10-20 parts of natural rubber, polyisoprene, or a combination thereof;

b. at least one reinforcing silica filler in an amount of 101-150 phr having a surface area of about 150 to about 300 m 2 /g;

c. no more than 20 phr of carbon black filler;

d. 30-50 phr of at least one hydrocarbon resin having a Tg of about 30 to about 50° C.;

e. 10-30 phr of liquid plasticizer; and

f. a cure package,

wherein the total amount of (d) and (e) is 40-70 phr.

2. The tire tread rubber composition of claim 1 , wherein the amount of (i) is 71-80 parts.

3. The tire tread rubber composition of claim 1 , wherein the hydrocarbon resin of (d) comprises an aromatic resin.

4. The tire tread rubber composition of claim 1 , wherein the styrene-butadiene rubber of (ii) has a styrene content of no more than about 25%.

5. The tire tread rubber composition of claim 1 , wherein the styrene-butadiene rubber of (ii) has a Tg of about −50 to about −75° C.

6. The tire tread rubber composition of claim 1 , wherein the elastomer component has an average Tg of −90 to −105° C.

7. The tire tread rubber composition of claim 1 , wherein the liquid plasticizer of (e) consists of one or more plant oils.

8. The tire tread rubber composition of claim 1 , wherein the total amount of (d) and (e) is 50 to 60 phr.

9. The tire tread rubber composition of claim 1 , wherein (d) and (e) are present in a weight ratio of 1.5/1 to 4/1.

10. The tire tread rubber composition of claim 1 , wherein (a) (iii) consists of natural rubber.

11. The tire tread rubber composition of claim 1 , wherein the elastomer component has an average Tg of −80 to −105° C.

12. The tire tread rubber composition of claim 1 , wherein the rubber composition has a value for tan δ at 60° C. of 0.23 to 0.29 and meets at least one of the following

a. has a value for tan δ at −30° C. of at least 1.1 times the tan δ at 60° C. value;

b. has a value for tan δ at 0° C. of at least 1.2 times the tan δ at 60° C. value; or

c. has a value for tan δ at 30° C. of at least 1.1 times the tan δ at 60° C. value.

13. The tire tread rubber composition of claim 12 , wherein each of (a), (b), and (c) are met.

14. The tire tread rubber composition of claim 1 , wherein at least one of the following is met:

(d) has an Eb at 23° C. of at least 450%,

(e) has an Eb at 100° C. of at least 400%, or

(f) has an Tb×Eb of at least 3000.

15. The tire tread rubber composition of claim 14 , wherein each of (d)-(f) is met.

16. A tire incorporating the tire tread rubber composition of claim 1 .

17. A tire tread rubber composition made of ingredients comprising:

a. 100 parts of an elastomer component comprising:

i. about 70 to about 80 parts of polybutadiene having a cis bond content of at least 95% and a Tg of less than −101° C.,

ii. about 10 to about 20 parts of at least one styrene-butadiene rubber having a Tg of less than −40° C.

iii. about 15 to about 25 parts of natural rubber, polyisoprene, or a combination thereof;

b. about 110 to about 130 phr of at least one reinforcing silica filler having a surface area of about 150 to about 300 m 2 /g;

c. no more than about 10 phr of carbon black filler;

d. about 35 to about 45 phr of at least one hydrocarbon resin having a Tg of about 30 to about 50° C.;

e. about 15 to about 25 phr of liquid plasticizer; and

f. a cure package;

wherein the total amount of (d) and (e) is at least about 50 phr.

18. The tire tread rubber composition of claim 17 , wherein the styrene-butadiene rubber of (ii) has a Tg of about −50 to about −75° C. and is functionalized with a silica-reactive functional group.

19. The tire tread rubber composition of claim 17 , wherein the total amount of (d) and (e) is no more than 65 phr and (d) and (e) are present in a weight ratio of 1.5/1 to 4/1.

20. A method of providing a tire tread having improved dry handling performance while maintaining wet traction performance and wear by utilizing a tire tread rubber composition made of ingredients comprising:

a. 100 parts of an elastomer component comprising:

i. 70-85 parts of polybutadiene having a cis bond content of at least 95% and a Tg of −101 to −110° C.,

ii. 10-25 parts of at least one styrene-butadiene rubber having a Tg of −40 to −75° C.

iii. 10-20 parts of natural rubber, polyisoprene, or a combination thereof;

b. at least one reinforcing silica filler in an amount of 101-150 phr having a surface area of about 150 to about 300 m 2 /g;

c. no more than 10 phr of carbon black filler;

d. 30-50 phr of at least one aromatic hydrocarbon resin having a Tg of about 30 to about 50° C.;

e. 10-30 phr of liquid plasticizer; and

f. a cure package,

wherein the total amount of (d) and (e) is 40 to 65 phr.

Assignments (1)

Continuity (2)

References Cited (400)