Tire inner-layer rubber composition and pneumatic tire

Patent metadata

Field	Value
Publication number	US-9567454-B2
Application number	US-201214368110-A
Country	US
Kind code	B2
Filing date	Oct 18, 2012
Priority date	Jan 20, 2012
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

The invention provides rubber compositions for tire inner layers, capable of providing excellent ozone resistance over a wide environmental temperature range and of preventing discoloration well, as well as pneumatic tires including such compositions. The invention relates to a rubber composition for tire inner layers, containing C20-C32 normal alkanes. Preferably, the combined amount of the C20-C32 normal alkanes is 0.1-2.5 parts by mass, and the combined amount of phenylenediamine and quinone antioxidants is 0-4 parts by mass, each per 100 parts by mass of the diene rubber component. The rubber composition for tire inner layers preferably contains C48 and higher normal alkanes in a combined amount of not more than 0.1 parts by mass per 100 parts by mass of the diene rubber component. The rubber composition preferably contains not more than 15 parts by mass of process oil per 100 parts by mass of the diene rubber component.

First claim

The invention claimed is:

1. A carcass topping comprising a rubber composition for tire inner layers, said rubber composition having a combined amount of C20 to C32 normal alkanes of 0.1 to 2.5 parts by mass, a combined amount of phenylenediamine and quinone antioxidants of 0 to 4 parts by mass, a combined amount of C45 to C47 normal alkanes of 0.01 to 0.5 parts by mass, and an amount of C48 and higher normal alkanes of 0 to 0.08 parts by mass, each per 100 parts by mass of a diene rubber component of the rubber composition,
wherein
a styrene-butadiene rubber content is 10 to 45% by mass, a polybutadiene rubber content is 0 to 40% by mass, and a combined content of natural rubber and polyisoprene rubber is 40 to 80% by mass, each based on 100% by mass of the diene rubber component, and
an amount of carbon black is 15 to 85 parts by mass per 100 parts by mass of the diene rubber component.

2. The carcass topping according to claim 1 ,
wherein a combined amount of C33 to C44 normal alkanes is 0.1 to 2.3 parts by mass per 100 parts by mass of the diene rubber component.

3. The carcass topping according to claim 1 ,
wherein a combined amount of C25 to C27 normal alkanes is 0.02 to 1.5 parts by mass per 100 parts by mass of the diene rubber component.

4. The carcass topping according to claim 1 ,
further comprising 0 to 15 parts by mass of process oil per 100 parts by mass of the diene rubber component.

5. The carcass topping according to claim 1 ,
further comprising 5 to 100 parts by mass of carbon black per 100 parts by mass of the diene rubber component.

6. A base tread comprising a rubber composition for tire inner layers, said rubber composition having a combined amount of C20 to C32 normal alkanes of 0.1 to 2.5 parts by mass, a combined amount of phenylenediamine and quinone antioxidants of 0 to 4 parts by mass, a combined amount of C45 to C47 normal alkanes of 0.01 to 0.5 parts by mass, and an amount of C48 and higher normal alkanes of 0 to 0.08 parts by mass, each per 100 parts by mass of a diene rubber component of the rubber composition,
wherein
a polybutadiene rubber content is 10 to 50% by mass and a combined content of natural rubber and polyisoprene rubber is 50 to 90% by mass, each based on 100% by mass of the diene rubber component, and
an amount of carbon black is 10 to 80 parts by mass per 100 parts by mass of the diene rubber component.

7. A pneumatic tire, comprising:
a carcass topping according to claim 1 ; and
sidewalls each having a thickness of 1.0 to 2.5 mm.

8. A pneumatic tire, comprising
a base tread according to claim 6 ,
the pneumatic tire having a minimum rubber thickness at a tread groove bottom subtread of 1.0 to 2.5 mm.

Assignees

• Sumitomo Rubber Ind

Inventors

• Miyazaki Tatsuya

Classifications

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08L7/00 Primary

  Compositions of natural rubber · CPC title

• C08K5/01

  Hydrocarbons {(C08K5/0091 takes precedence)} · CPC title

• Y02T10/862

  Cross-Sectional Technologies · mapped topic

• C08L9/06

  Copolymers with styrene · CPC title