# US 7,608,667 B2 · Rubber composition and tire using the same

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- Number: US 7,608,667 B2
- Document ID: US7608667B2
- Status: Granted
- Kind: B2
- Application number: 11/275,860
- Filed: 2006-02-01
- Published: 2006-08-03
- Granted: 2009-10-27
- Earliest claimed: 2005-02-03
- Assignees: Bridgestone Corporation
- Inventors: Noriko Endo
- Web page: https://patentgrep.com/patent/US7608667B2

## CPC

- C08L 9/06: Copolymers with styrene
- B60C 1/0016: {Compositions of the tread}
- C08L 15/00: Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence)
- C08C 19/02: Hydrogenation
- 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

A rubber composition comprises as a rubber component (A) an aromatic vinyl compound-conjugated diene compound copolymer polymerized with a lithium-based polymerization initiator and having a polystyrene-conversion weight average molecular weight of 3.0×105−3.0×106 as measured by a gel permeation chromatography and (B) 10-200 parts by mass, based on 100 parts by mass of the copolymer (A), of a hydrogenated styrene-butadiene copolymer having a polystyrene-conversion weight average molecular weight of 5.0×103−2.0×105 as measured by a gel permeation chromatography and a bound styrene content of 10-70 mass % in which 25-50% of double bonds in butadiene portion is hydrogenated.

## Claims

### Claim 1

A rubber composition comprising as a rubber component (A) an aromatic vinyl compound-conjugated diene compound copolymer polymerized with a lithium-based polymerization initiator and having a polystyrene-conversion weight average molecular weight of 3.0×105−3.0×106 as measured by a gel permeation chromatography and (B) 10-200 parts by mass, based on 100 parts by mass of the copolymer (A), of a hydrogenated styrene-butadiene copolymer having a polystyrene-conversion weight average molecular weight of 5.0×103−2.0×105 as measured by a gel permeation chromatography and a bound styrene content of 10-70 mass % in which 25-50% of double bonds in butadiene portion is hydrogenated.

### Claim 2 (depends on 1)

A rubber composition according to claim 1, wherein the aromatic vinyl compound-conjugated diene compound copolymer (A) is a styrene-butadiene copolymer.

### Claim 3 (depends on 2)

A rubber composition according to claim 2, wherein the bound styrene content of the aromatic vinyl compound-conjugated diene compound copolymer (A) is 20-40 mass %.

### Claim 4 (depends on 2)

A rubber composition according to claim 2, wherein the vinyl bond content in the butadiene portion of the aromatic vinyl compound-conjugated diene compound copolymer (A) is 30-60%.

### Claim 5 (depends on 1)

A rubber composition according to claim 1, wherein 35-50% of double bonds in the butadiene portion of the hydrogenated styrene-butadiene copolymer (B) is hydrogenated.

### Claim 6 (depends on 1)

A rubber composition according to claim 1, wherein the bound styrene content of the hydrogenated styrene-butadiene copolymer (B) is 10-60 mass %.

### Claim 7 (depends on 1)

A rubber composition according to claim 1, wherein the hydrogenated styrene-butadiene copolymer (B) is compounded in an amount of 20-100 parts by mass based on 100 parts by mass of the aromatic vinyl compound-conjugated diene compound copolymer (A).

### Claim 8 (depends on 1, 2, 3, 4, 5, 6, 7)

A pneumatic tire characterized by using as a tread rubber a rubber composition as claimed in any one of claims 1 to 7.