# US 12,215,231 B2 · Tire tread rubber composition

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,215,231 B2
- Document ID: US12215231B2
- Status: Granted
- Kind: B2
- Application number: 17/344,060
- Filed: 2021-06-10
- Published: 2021-09-30
- Granted: 2025-02-04
- Earliest claimed: 2018-05-04
- Assignees: Bridgestone Americas Tire Operations, LLC
- Applicants: Bridgestone Americas Tire Operations, LLC
- Inventors: James P. Kleckner; Anthony M. Unger; Benjamin C. Galizio
- Web page: https://patentgrep.com/patent/US12215231B2

## CPC

- C08L 7/00: Compositions of natural rubber
- C08L 9/06: Copolymers with styrene
- B60C 1/0016: {Compositions of the tread}
- B60C 11/0008: {characterised by the tread rubber}
- C08C 19/25: Incorporating silicon atoms into the molecule
- C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L 15/00: Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence)
- B60C 2011/0025: {Modulus or tan delta}
- C08L 2205/03: containing three or more polymers in a blend
- C08L 2207/04: Thermoplastic elastomer
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- C08C: TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS

## Abstract

Disclosed herein are tire tread rubber compositions comprising a specified elastomer component, reinforcing silica filler, a specified hydrocarbon resin, a cure package, and optionally oil. The elastomer component includes styrene-butadiene rubber and polybutadiene.

## Claims

### Claim 1

A tire tread rubber composition comprising:
a. 100 parts of an elastomer component comprising
i. 30-50 parts of solution-polymerized styrene-butadiene rubber,
ii. 30-50 parts of polybutadiene rubber having a cis bond content of at least 95% and a Tg of less than −101° C., and
iii. 20-40 parts of natural rubber consisting of guayule natural rubber,
wherein any additional diene-monomer containing rubber is present in an amount of no more than 5 parts,
b. at least one reinforcing silica filler in an amount of 81-120 phr,
c. no more than 15 phr of carbon black filler,
d. 11-35 phr of at least one hydrocarbon resin having a Tg of about 30 to about 50° C.,
e. 0-40 phr oil, and
f. a cure package,
wherein the total amount of (d) and (e) is no more than 59 phr.

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 1)

The tire tread rubber composition of claim 1 wherein the at least one hydrocarbon resin of (d) is an aromatic hydrocarbon resin and is present in an amount of 11-30 phr
and wherein the total amount of (d) and (e) is no more than 49 phr.

### Claim 4 (depends on 1)

The tire tread rubber composition of claim 1, wherein the styrene-butadiene rubber of (i) has a styrene monomer content of 25-35 weight %.

### Claim 5 (depends on 1)

The tire tread rubber composition of claim 1, wherein the styrene-butadiene rubber of (i) is oil-extended with 30-40 parts of at least one oil per 100 parts of styrene-butadiene rubber.

### Claim 6 (depends on 1)

The tire tread rubber composition of claim 1, having a total oil content of 15-25 phr.

### Claim 7 (depends on 1)

The tire tread rubber composition of claim 1, wherein the hydrocarbon resin of (d) includes less than 5 phr of terpene resin.

### Claim 8 (depends on 1)

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

### Claim 9 (depends on 1)

The tire tread rubber composition of claim 1, wherein any oil present contains 50% by weight or less oleic acid.

### Claim 10 (depends on 1)

The tire tread rubber composition of claim 1, wherein (c) comprises no more than 10 phr of carbon black filler.

### Claim 11 (depends on 1)

The tire tread rubber composition of claim 1, wherein the total amount of (d) and (e) is 20-44 phr.

### Claim 12 (depends on 1)

The tire tread rubber composition of claim 1, wherein each of (a), (b), and (c) are met.

### Claim 13 (depends on 1)

The tire tread rubber composition of claim 1 wherein the styrene-butadiene rubber of (a)(i) has
a vinyl bond content of no more than 20% and a Tg of about −40 to about −50° C.
and wherein the total amount of (d) and (e) is no more than 50 phr.

### Claim 14 (depends on 13)

The tire tread rubber composition of claim 13, wherein the at least one hydrocarbon resin of (d) comprises an aromatic resin.

### Claim 15 (depends on 14)

The tire tread rubber composition of claim 14, wherein the aromatic hydrocarbon resin has a Tg of about 35 to about 50° C.

### Claim 16 (depends on 1)

The tire tread rubber composition of claim 1, wherein the rubber composition has a value for tan δ at 60° C. of 0.18 to 0.25 and meets at least one of the following
a. has a value for tan δ at −30° C. of at least 1.5 times the tan δ at 60° C. value;
b. has a value for tan δ at 0° C. of at least 1.4 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.

### Claim 17 (depends on 16)

The tire tread rubber composition of claim 16, wherein the total amount of (d) and (e) is 20-44 phr.

### Claim 18 (depends on 17)

The tire tread rubber composition of claim 17, wherein the total amount of (d) and (e) is 20-44 phr.

### Claim 19 (depends on 1)

A tire including a tread comprising the tire tread rubber composition of claim 1.