Rubber composition and pneumatic tire

Patent metadata

Field	Value
Publication number	US-9139719-B2
Application number	US-201113702245-A
Country	US
Kind code	B2
Filing date	Jul 22, 2011
Priority date	Jul 23, 2010
Publication date	Sep 22, 2015
Grant date	Sep 22, 2015

Abstract

The present invention provides a rubber composition that achieves a well-balanced improvement in fuel economy, wet-grip performance, and abrasion resistance, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition, including a rubber component and silica, wherein the rubber component contains not less than 5% by mass of a conjugated diene polymer, based on 100% by mass of the rubber component, the conjugated diene polymer containing a constituent unit derived from a conjugated diene and a constituent unit represented by the following formula (I):

at least one terminal of the conjugated diene polymer being modified by a compound containing a group represented by the following formula (II):

and wherein the silica is contained in an amount of 5 to 150 parts by mass per 100 parts by mass of the rubber component.

First claim

The invention claimed is:

1. A rubber composition, comprising a rubber component and silica, wherein the rubber component comprises 10 to 60% by mass natural rubber and 10 to 60% by mass butadiene rubber, based on 100% by mass of the rubber component, and the rubber component contains not less than 5% by mass of a conjugated diene polymer, based on 100% by mass of the rubber component, and
wherein the silica is contained in an amount of 5 to 150 parts by mass per 100 parts by mass of the rubber component,
the conjugated diene polymer comprising a constituent unit derived from a conjugated diene and a constituent unit represented by the following formula (I):

wherein X 1 , X 2 , and X 3 each independently represent a group represented by the formula (Ia) below, a hydroxyl group, a hydrocarbyl group, or a substituted hydrocarbyl group, and at least one of the X 1 , X 2 , and X 3 is a hydroxyl group or a group represented by the formula (Ia):

wherein R 1 and R 2 each independently represent a C 1-6 hydrocarbyl group, a C 1-6 substituted hydrocarbyl group, a silyl group, or a substituted silyl group, and the R 1 and R 2 may be bonded to each other to form a cyclic structure together with the nitrogen atom,
at least one terminal of the conjugated diene polymer being modified by a compound containing a group represented by the following foiinula (II):

wherein m represents an integer of 1 to 11; and A represents a functional group containing a nitrogen atom.

2. The rubber composition according to claim 1 ,
wherein the R 1 and R 2 in the formula (Ia) are C 1-6 hydrocarbyl groups.

3. The rubber composition according to claim 1 ,
wherein two of the X 1 , X 2 , and X 3 in the formula (I) are selected from the group consisting of a group represented by the formula (Ia) and a hydroxyl group.

4. The rubber composition according to claim 1 ,
wherein the compound containing a group represented by the formula (II) is a compound represented by the following formula (III):

wherein n represents an integer of 0 to 10; R 3 represents a C 1-5 hydrocarbyl group; R 4 , R 5 , R 6 , and R 7 each independently represent a hydrogen atom, a C 1-5 hydrocarbyl group, a C 1-5 substituted hydrocarbyl group, or a C 1-5 hydrocarbyloxy group, and when a plurality of R 4 s and a plurality of R 5 s are present, the plurality of R 4 s and the plurality of R 5 s may be the same or different from one another; R 8 and R 9 each independently represent a C 1-6 group optionally containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a silicon atom, the R 8 and R 9 may be bonded to each other to form a cyclic structure together with the nitrogen atom, and the R 8 and R 9 may form a single group bonded to the nitrogen via a double bond.

5. The rubber composition according to claim 4 ,
wherein one of the R 6 and R 7 in the formula (III) is a hydrogen atom.

6. The rubber composition according to claim 1 ,
wherein the conjugated diene polymer has a vinyl bond content of at least 10 mol % but not more than 80 mol %, based on 100 mol % of the constituent unit derived from a conjugated diene.

7. The rubber composition according to claim 1 ,
wherein the silica has a nitrogen adsorption specific surface area of 40 to 400 m 2 /g.

8. The rubber composition according to claim 1 , which is for use as a rubber composition for a tread.

9. A pneumatic tire, formed from the rubber composition according to claim 1 .

Assignees

• Hinohara Yuko
• Nishioka Kazuyuki
• Mabuchi Takahiro
• Sumitomo Rubber Ind

Inventors

• Hinohara Yuko
• Nishioka Kazuyuki
• Mabuchi Takahiro

Classifications

• Y02T10/862

  Cross-Sectional Technologies · mapped topic

• C08L15/00 Primary

  Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence) · CPC title

• C08L9/06 Primary

  Copolymers with styrene · CPC title

• B60C1/0016 Primary

  Compositions of the tread · CPC title

• C08K3/36

  Silica · CPC title