# US 12,760,170 B2 · Rubber composition and pneumatic tire

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- Number: US 12,760,170 B2
- Document ID: US12760170B2
- Status: Granted
- Kind: B2
- Application number: 18/031,650
- Filed: 2021-12-08
- Published: 2023-11-30
- Granted: 2026-10-13
- Earliest claimed: 2020-12-10
- Assignees: Bridgestone Corporation
- Applicants: Bridgestone Corporation
- Inventors: Nao Kawakami
- Web page: https://patentgrep.com/patent/US12760170B2

## CPC

- C08L 9/06: Copolymers with styrene
- B60C 1/00: Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
- C08K 3/36: Silica
- C08K 9/04: Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)}
- C08L 7/00: Compositions of natural rubber
- C08K 2201/006: Additives being defined by their surface area
- C08L 2201/50: Aqueous dispersion, e.g. containing polymers with a glass transition temperature (Tg) above 20°C
- C08L 2201/52: Aqueous emulsion or latex, e.g. containing polymers of a glass transition temperature (Tg) below 20°C
- 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
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)

## Abstract

Provided are a pneumatic tire in which balance between dry steering stability and low rolling resistance is improved while excellent on-ice performance and wet grip performance are maintained, and a rubber composition from which the tire is obtained. The rubber composition contains a rubber component containing a natural rubber and a modified styrene-butadiene copolymer rubber having a glass transition temperature of −50° C. or lower, a resin, a filler containing silica having a cetyltrimethylammonium bromide specific surface area of 190 m2/g or more, and an oil component. A content of the modified styrene-butadiene copolymer rubber in the rubber component is more than 50% by mass.

## Claims

### Claim 1

A rubber composition comprising:
a rubber component comprising a natural rubber and a modified styrene-butadiene copolymer rubber having a glass transition temperature of −50° C. or lower;
a resin;
a filler comprising silica having a cetyltrimethylammonium bromide specific surface area of 190 m2/g or more; and
an oil component, wherein
a content of the modified styrene-butadiene copolymer rubber in the rubber component is more than 50% by mass,
the filler comprises aluminum hydroxide,
a ratio (s/a) of a content(s) of the silica to a content (a) of the aluminum hydroxide is 5 to 10 on a mass basis,
the content of the silica having a cetyltrimethylammonium bromide specific surface area of 190 m2/g or more is 100% by mass in a total amount of all silica, and
the rubber component further comprises 1% to 30% by mass of a modified styrene-butadiene copolymer rubber having a glass transition temperature of −40° C. or higher.

### Claim 2 (depends on 1)

The rubber composition according to claim 1, wherein
the silica is comprised in an amount of 60 parts by mass or more per 100 parts by mass of the rubber component.

### Claim 3 (depends on 2)

The rubber composition according to claim 2, wherein
the oil component is comprised in an amount of more than 0 parts by mass and 20 parts by mass or less per 100 parts by mass of the rubber component.

### Claim 4 (depends on 2)

The rubber composition according to claim 2, wherein
the resin has a glass transition temperature of higher than 60° C.

### Claim 5 (depends on 2)

A pneumatic tire using:
the rubber composition according to claim 2.

### Claim 6 (depends on 1)

The rubber composition according to claim 1, wherein
the aluminum hydroxide is comprised in an amount of 1 to 20 parts by mass per 100 parts by mass of the rubber component.

### Claim 7 (depends on 1)

The rubber composition according to claim 1, wherein
the oil component is comprised in an amount of more than 0 parts by mass and 20 parts by mass or less per 100 parts by mass of the rubber component.

### Claim 8 (depends on 1)

The rubber composition according to claim 1, wherein
the resin has a glass transition temperature of higher than 60° C.

### Claim 9 (depends on 1)

A pneumatic tire using:
the rubber composition according to claim 1.