TIRE RUBBER COMPOSITION AND TIRE

• US 20190309146A1
• Filed: 03/13/2019
• Published: 10/10/2019
• Est. Priority Date: 04/09/2018
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: YOKOYAMA, Yuka, IZUMO, Suguru
• Granted Patent: US 10,844,199 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 1/0016 Compositions of the tread
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/06 Sulfur
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 5/09 Carboxylic acids; Metal salts thereof; Anhydrides thereof
• CPC Class Codes: C08K 5/18 with aromatically bound amino groups
• CPC Class Codes: C08K 5/31 Guanidine; Derivatives thereof
• CPC Class Codes: C08K 5/47 Thiazoles
• CPC Class Codes: C08K 5/548 containing sulfur C08K5/5477 takes precedence
• CPC Class Codes: C08L 15/00 Compositions of rubber derivatives C08L11/00, C08L13/00 take precedence
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 2205/035 containing four or more polymers in a blend
• CPC Class Codes: C08L 23/00 Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 25/08 Copolymers of styrene C08L29/08, C08L35/06, C08L55/02 take precedence
• CPC Class Codes: C08L 57/02 Copolymers of mineral oil hydrocarbons
• CPC Class Codes: C08L 7/00 Compositions of natural rubber
• CPC Class Codes: C08L 9/00 Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
• CPC Class Codes: C08L 9/06 Copolymers with styrene
• CPC Class Codes: C08L 91/00 Compositions of oils, fats or waxes; Compositions of derivatives thereof
• CPC Class Codes: C08L 91/06 : Waxes

Abstract

Provided is a rubber composition for tires that provides a balanced improvement of wet grip, abrasion resistance, handling stability, and fuel economy during high-speed running, and further has less performance degradation after long-term service. Also provided is a tire including the rubber composition. Included is a rubber composition for tires containing, based on 100% by mass of a rubber component therein: 3-25% by mass of a component derived from an aromatic vinyl monomer; 0-15% by mass of a component derived from a butadiene monomer and having a vinyl configuration; 1-90% by mass of a component derived from a butadiene monomer and having a cis configuration; and 1-6% by mans of a component derived from an isoprene monomer and having a cis configuration, the rubber composition having, after vulcanization, physical properties satisfying the following relationships (1) and (2):

−25° C.<Tg<0° C.   (1); and

65<Hs<75   (2).

Claims

1. A tire, comprising a cap tread,

the cap tread comprising a rubber composition for tires,

the rubber composition comprising, based on 100% by mass of a rubber component therein:

3 to 25% by mass of a component derived from an aromatic vinyl monomer;

0 to 15% by mass of a component derived from a butadiene monomer and having a vinyl configuration;

1 to 90% by mass of a component derived from a butadiene monomer and having a cis configuration; and

1 to 6% by mass of a component derived from an isoprene monomer and having a cis configuration,

the rubber composition having, after vulcanization, physical properties satisfying the following relationships (1) and (2);

−

25°

C.<

Tg<

0°

C.  

 

(1)

wherein Tg denotes a temperature at tan δ

peak determined by viscoelastic measurements at a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain amplitude of 0.25%; and

65<

Hs<

75  

 

(2)

wherein Hs denotes a hardness at 23°

C. measured in accordance with. JIS K6253.

2. The tire according to claim 1,

wherein the rubber composition has a viscoelastic spectrum with a single peak at −

80°

C. or higher obtained by viscoelastic measurements at a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain amplitude of 0.25%.

3. The tire according to claim 2,

wherein the viscoelastic spectrum shows a single peak at −

90°

C. or higher.

4. The tire according to claim 1,

wherein the rubber composition has, after vulcanization, physical properties satisfying the following relationships (3) and (4):

tan δ

1>

0.80  

 

(3) and

tan δ

2<

0.15  

 

(4)

wherein tan δ

1 denotes a tan δ

at −

5°

C. determined by viscoelastic measurements at a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain amplitude of 2%, and

tan δ

2 denotes a tan δ

at 80°

C. determined by viscoelastic measurements at a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain amplitude of 2%.

5. The tire according to claim 1,

wherein the rubber component comprises a solution-polymerized styrene butadiene rubber that has 25% by mass or less of a component derived from a butadiene monomer and having a vinyl configuration based on 100% by mass of components derived from a butadiene monomer.

6. The tire according to claim 5,

wherein the solution-polymerized styrene butadiene rubber has a weight average molecular weight of 800,000 or more.

7. The tire according to claim 1,

wherein the rubber component comprises at least one selected from the group consisting of hydrogenated styrene butadiene rubbers, styrene-based thermoplastic elastomers, and olefin/conjugated diene/styrene copolymers.

8. The tire according to claim 1,

wherein the rubber composition comprises silica in an amount of 100 to 300 parts by mass per 100 parts by mass of the rubber component.

9. The tire according to claim 1,

wherein the rubber component has a single phase morphology.

10. The tire according to claim 1,

wherein the rubber composition comprises a resin having a softening point of 25°

C. or higher in an amount of 1 to 60 parts by mass per 100 parts by mass of the rubber component.

11. The tire according to claim 10,

wherein the resin is at least one selected from the group consisting of styrene-based resins, terpene-based resins, C5 resins, C5/C9 resins, DCPD-based resins, and rosin-based resins.

12. The tire according to claim 1,

wherein the tire comprises a base tread comprising a rubber composition that comprises, based on 100% by mass of a rubber component therein, 10% by mass or more of a styrene butadiene rubber.