Rubber composition for use in tires

• US 8,362,118 B2
• Filed: 12/06/2010
• Issued: 01/29/2013
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Mihara, Satoshi
• Primary Examiner(s): NERANGIS, VICKEY M
• Application Number:
  US12/961,345
• Publication Number:
  US 20110144236A1
• Time in Patent Office: 785 Days
• Field of Search: 524/77, 524/492, 524/493, 524/575
• US Class Current: 524/77
• CPC Class Codes: B60C 1/0016 Compositions of the tread
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08L 15/00 Compositions of rubber derivatives C08L11/00, C08L13/00 take precedence
• CPC Class Codes: C08L 2312/00 Crosslinking
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: C08L 57/02 Copolymers of mineral oil hydrocarbons
• CPC Class Codes: C08L 65/00 Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 9/00 Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Abstract

A rubber composition for use in tires including from 60 to 120 parts by weight of a silica having a CTAB specific surface area of from 70 to 175 m²/g and from 3 to 25 parts by weight of an aromatic modified terpene resin excluding terpene phenol resins per 100 parts by weight of a diene rubber including from 30 to 80 weight % of a terminal-modified styrene-butadiene rubber and from 10 to 50 weight % of a butadiene rubber. An average glass transition temperature of the diene rubber is −55° C. or lower and an average glass transition temperature of a component formed from the diene rubber, the aromatic modified terpene resin, and an optional plasticizer is −45° C. or lower.

Claims

1. A rubber composition for use in tires comprising:

from 60 to 120 parts by weight of a silica having a CTAB specific surface area of from 80 to 170 m²/g and from 3 to 20 parts by weight of an aromatic modified terpene resin excluding terpene phenol resins per 100 parts by weight of a diene rubber comprising from 30 to 80 weight % of a terminal-modified styrene-butadiene rubber and from 10 to 50 weight % of a butadiene rubber;

wherein the total of the terminal-modified styrene-butadiene rubber and the butadiene rubber is from 60 to 100 weight % based on the amount of the diene rubber, the terminal functional group of the terminal-modified styrene-butadiene rubber is a hydroxy group or an N-methylpyrrolidone group, the average glass transition temperature of the diene rubber is −

55°

C. to −

70°

C., the average glass transition temperature of a compound formed from the diene rubber, the aromatic modified terpene resin, and an optional oil component-containing plasticizer is from −

45°

C. to −

60°

C., the hydroxy value of the aromatic modified terpene resin is from 0 to 25 KOH mg/g, and the glass transition temperature of the aromatic modified terpene resin is from 20 to 80°

C.

2. The rubber composition for use in tires according to claim 1, further comprising a terpene phenol resin having a hydroxy value of from 0 to 20 KOH mg/g as the plasticizer, wherein the compounded amount (B) of said terpene phenol resin is adjusted so that, in relation to a compounded amount (A) of the aromatic modified terpene resin, the weight ratio B/(A+B) is 0.9 or less.

3. The rubber composition according to claim 2, wherein the weight ratio B/(A+B) is from 0.1 to 0.7.

4. The rubber composition for use in tires according to claim 1, comprising from 60 to 100 parts by weight of the silica.

5. The rubber composition for use in tires according to claim 1, further comprising a silane coupling agent in an amount of from 3 to 15 weight % with respect to the amount of the silica.

6. The rubber composition for use in tires according to claim 5, wherein the silane coupling agent is from 4 to 10 weight % with respect to the amount of the silica.

7. The rubber composition according to claim 1, wherein the diene rubber comprises an amount of styrene from 14 to 40 weight %.

8. The rubber composition according to claim 7, wherein the diene rubber comprises an amount of styrene from 20 to 35 weight %.

9. The rubber composition according to claim 1, wherein the diene rubber comprises an amount of vinyl from 10 to 75 weight %.

10. The rubber composition according to claim 9, wherein the diene rubber comprises an amount of vinyl from 30 to 70 weight %.

11. The rubber composition according to claim 1, wherein the average glass transition temperature is from −

55 to −

65°

C.

12. The rubber composition according to claim 1, wherein the diene rubber comprises from 15 to 45 weight % of the butadiene rubber.

13. The rubber composition according to claim 1, comprising from 5 to 20 parts by weight of the aromatic modified terpene resin per 100 parts by weight of the diene rubber.

16. A studless tire using the rubber composition for use in tires according to claim 1 in a tread portion.

14. A rubber composition for use in tires comprising:

from 60 to 120 parts by weight of a silica having a CTAB specific surface area of from 80 to 170 m²/g and from 3 to 20 parts by weight of an aromatic modified terpene resin excluding terpene phenol resins per 100 parts by weight of a diene rubber comprising from 30 to 80 weight % of a terminal-modified styrene-butadiene rubber and from 10 to 50 weight % of a butadiene rubber;

wherein the total of the terminal-modified styrene-butadiene rubber and the butadiene rubber is from 60 to 100 weight % based on the amount of the diene rubber, the terminal functional group of the terminal-modified styrene-butadiene rubber is a hydroxy group or an N-methylpyrrolidone group, the average glass transition temperature of the diene rubber is −

55°

C. to −

70°

C., the average glass transition temperature of a compound formed from the diene rubber and the aromatic modified terpene resin is from −

45°

C. to −

60°

C., the hydroxy value of the aromatic modified terpene resin is from 0 to 25 KOH mg/g, and the glass transition temperature of the aromatic modified terpene resin is from 20 to 80°

C.

15. A rubber composition for use in tires comprising:

from 60 to 120 parts by weight of a silica having CTAB specific surface area of from 80 to 170 m²/g and from 3 to 20 parts by weight of an aromatic modified terpene resin excluding terpene phenol resins per 100 parts by weight of a diene rubber comprising from 30 to 80 weight % of a terminal-modified styrene-butadiene rubber and from 10 to 50 weight % of a butadiene rubber; and

an oil component-containing plasticizer;

wherein the total of the terminal-modified styrene-butadiene rubber and the butadiene rubber is from 60 to 100 weight % based on the amount of the diene rubber, the terminal functional group of the terminal-modified styrene-butadiene rubber is a hydroxy group or an N-methylpyrrolidone group, the average glass transition temperature of the diene rubber is −

55°

C. to −

70°

C., the average glass transition temperature of a compound formed from the diene rubber, the aromatic modified terpene resin and the oil component-containing plasticizer is from −

45°

C. to −

60°

C., the hydroxy value of the aromatic modified terpene resin is from 0 to 25 KOH mg/g, and the glass transition temperature of the aromatic modified terpene resin is from 20 to 80°

C.