Rubber composition and pneumatic tire having tread fabricated using rubber composition

Patent metadata

Field	Value
Publication number	US-2016288570-A1
Application number	US-201415034715-A
Country	US
Kind code	A1
Filing date	Jul 29, 2014
Priority date	Nov 19, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

Provided are a rubber composition that shows a balanced improvement in fuel economy, abrasion resistance, and wet grip performance while having good processability, and a pneumatic tire including a tread formed from the rubber composition. The present invention relates to a rubber composition containing: a copolymer synthesized by copolymerization of a conjugated diene monomer and a compound represented by the formula (1) below; and carbon black and/or silica,

wherein R 11 and R 12 are the same as or different from each other and each represent a hydrogen atom or a C1-C30 hydrocarbon group.

First claim

1 . A pneumatic tire, comprising:
a tread comprising a rubber composition comprising a copolymer and at least one of carbon black and silica, wherein the copolymer comprises a first monomer unit derived from 1, 3-butadiene and a second monomer unit derived from a compound represented by formula (1)

where R 11 and R 12 are the same or different from each other and each represent a hydrogen atom or a C1-C30 hydrocarbon group.

2 . The pneumatic tire according to claim 1 , wherein the copolymer comprises the first monomer unit in a range of 5% to 95% by mass and the second monomer unit in a range of 5% to 95% by mass per 100% by mass of structural units of the copolymer.

3 . The pneumatic tire according to claim 1 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization, and the copolymer has a weight average molecular weight in a range of 5,000 to 2,000,000 and a molecular weight distribution in a range of 2.1 to 11.

4 . The pneumatic tire according to claim 1 , wherein R 11 and R 12 are ethyl groups.

5 . (canceled)

6 . The pneumatic tire according to claim 1 , wherein the copolymer further comprises a third monomer unit derived from a compound represented by formula (2)

where R 21 represents a hydrogen atom, a C1-C3 aliphatic hydrocarbon group, a C3-C8 alicyclic hydrocarbon group, or a C6-C10 aromatic hydrocarbon group, and R 22 represents a hydrogen atom or a methyl group, and the copolymer comprises the third monomer unit in a range of 1% to 50% by mass per 100% by mass of structural units of the copolymer.

7 - 8 . (canceled)

9 . The pneumatic tire according to claim 1 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization in the presence of a chain transfer agent.

10 . The pneumatic tire according to claim 1 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) in the presence of a chain transfer agent comprising a compound having a mercapto group and a functional group having an affinity for filler.

11 . The pneumatic tire according to claim 1 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization, and the copolymer has a glass transition temperature in a range of −100° C. to 100° C. and a Mooney viscosity ML 1+4 at 130° C. in a range of 30 to 100.

12 . The pneumatic tire according to claim 2 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization, and the copolymer has a weight average molecular weight in a range of 5,000 to 2,000,000 and a molecular weight distribution in a range of 2.1 to 11.

13 . The pneumatic tire according to claim 2 , wherein R 11 and R 12 are ethyl groups.

14 . The pneumatic tire according to claim 2 , wherein the copolymer further comprises a third monomer unit derived from a compound represented by formula (2),

where R 21 represents a hydrogen atom, a C1-C3 aliphatic hydrocarbon group, a C3-C8 alicyclic hydrocarbon group, or a C6-C10 aromatic hydrocarbon group, and R 22 represents a hydrogen atom or a methyl group, and the copolymer comprises the third monomer unit in a range of 1% to 50% by mass per 100% by mass of structural units of the copolymer.

15 . The pneumatic tire according to claim 2 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization in the presence of a chain transfer agent.

16 . The pneumatic tire according to claim 2 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) in the presence of a chain transfer agent comprising a compound having a mercapto group and a functional group having an affinity for filler.

17 . The pneumatic tire according to claim 2 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization, and the copolymer has a glass transition temperature in a range of −100° C. to 100° C. and a Mooney viscosity ML 1+4 at 130° C. in a range of 30 to 100.

18 . The pneumatic tire according to claim 3 , wherein R 11 and R 12 are ethyl groups.

19 . The pneumatic tire according to claim 3 , wherein the copolymer is produced by further emulsion polymerizing a compound represented by formula (2),

where R 21 represents a hydrogen atom, a C1-C3 aliphatic hydrocarbon group, a C3-C8 alicyclic hydrocarbon group, or a C6-C 10 aromatic hydrocarbon group, and R 22 represents a hydrogen atom or a methyl group, and the copolymer comprises 1% to 50% by mass of units derived from the compound represented by the formula (2) per 100% by mass of structural units of the copolymer.

20 . The pneumatic tire according to claim 3 , wherein the copolymer is produced by the emulsion polymerization in the presence of a chain transfer agent.

21 . The pneumatic tire according to claim 3 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) in the presence of a chain transfer agent comprising a compound having a mercapto group and a functional group having an affinity for filler.

22 . The pneumatic tire according to claim 3 , wherein the copolymer is produced by synthesizing the 1, 3-butadiene and the compound represented by the formula (1) by emulsion polymerization, and the copolymer has a glass transition temperature in a range of −100° C. to 100° C. and a Mooney viscosity ML 1+4 at 130° C. in a range of 30 to 100.

23 . The pneumatic tire according to claim 4 , wherein the copolymer further comprises a third monomer unit derived from a compound represented by formula (2),

where R 2 ′ represents a hydrogen atom, a C1-C3 aliphatic hydrocarbon group, a C3-C8 alicyclic hydrocarbon group, or a C6-C 10 aromatic hydrocarbon group, and R 22 represents a hydrogen atom or a methyl group, and the copolymer comprises the third monomer unit in a range of 1% to 50% by mass per 100% by mass of structural units of the copolymer.

Assignees

• Sumitomo Rubber Ind

Inventors

• Fujisawa Koji
• HIGA Gen
• Kitamura Satoko
• Mabuchi Takahiro
• TORITA Kazuya

Classifications

• B60C1/0016 Primary

  Compositions of the tread · CPC title

• C08K3/04

  Carbon · CPC title

• B60C11/0008

  characterised by the tread rubber · CPC title

• C08K3/36

  Silica · CPC title

• C08F2/38

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title