Rubber composition for tread and tire

Patent metadata

Field	Value
Publication number	US-10703138-B2
Application number	US-201815896511-A
Country	US
Kind code	B2
Filing date	Feb 14, 2018
Priority date	Feb 15, 2017
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

The rubber composition for a tread comprises: 5 to 30 parts by mass of a carbon black, 95 parts by mass or more of silica, 25 parts by mass or more of a powder of an inorganic compound represented by a given formula (A) and having an average primary particle size of 10 μm or less, and 70 parts by mass or more of a softening agent comprising 2 to 15 parts by mass of a coumarone-based resin, based on 100 parts by mass of a rubber component comprising 70% by mass or more of a styrene-butadiene rubber having a styrene content of from 20 to 50% by mass and a vinyl content of from 15 to 65%, and the tire has a tread composed of the rubber composition for a tread.

First claim

What is claimed is:

1. A rubber composition for a tread comprising:
5 to 20 parts by mass of a carbon black,
95 parts by mass or more of silica,
wherein a nitrogen adsorption specific surface area of the silica is 40 to 500 m 2 /g,
35 parts by mass to 50 parts by mass of a powder of an inorganic compound represented by the following formula (A) and having an average primary particle size of 10 μm or less, and
70 parts by mass or more of a softening agent comprising 2 to 15 parts by mass of a coumarone-based resin,

based on 100 parts by mass of a rubber component comprising 70% by mass or more of a styrene-butadiene rubber having a styrene content of from 20 to 50% by mass and a vinyl content of from 15 to 65%,
M.αSiO 2 .βH 2 O  (A)

wherein in formula (A), M is an oxide or hydroxide of at least one metal selected from Al, Mg, Ti and Ca, and each of α and β is an integer of from 0 to 10, and
wherein the coumarone-based resin is an only resin of the rubber composition.

2. A rubber composition for a tread comprising:
5 to 30 parts by mass of a carbon black,
not less than 120 parts by mass or more of silica,
wherein a nitrogen adsorption specific surface area of the silica is 40 to 500 m 2 /g,
25 parts by mass or more of a powder of an inorganic compound represented by the following formula (A) and having an average primary particle size of 10 μm or less, and
70 parts by mass or more of a softening agent comprising 2 to 15 parts by mass of a coumarone-based resin,

based on 100 parts by mass of a rubber component comprising 70% by mass or more of a styrene-butadiene rubber having a styrene content of from 20 to 50% by mass and a vinyl content of from 15 to 65%,
M.αSiO 2 .βH 2 O  (A)

wherein in formula (A), M is an oxide or hydroxide of at least one metal selected from Al, Mg, Ti and Ca, and each of α and β is an integer of from 0 to 10, and
wherein the coumarone-based resin is an only resin of the rubber composition.

3. The rubber composition for a tread of claim 1 , wherein the softening agent comprises 11 to 20 parts by mass of bis(2-ethylhexyl)sebacate.

4. The rubber composition for a tread of claim 1 , wherein the powder of an inorganic compound is made of aluminum oxide and/or aluminum hydroxide.

5. A tire having a tread composed of the rubber composition for a tread of claim 1 .

6. A rubber composition for a tread comprising:
5 to 20 parts by mass of a carbon black,
120 to 200 parts by mass of silica,
35 to 50 parts by mass of a powder of an inorganic compound represented by the following formula (A) and having an average primary particle size of 10 μm or less, and
70 parts by mass or more of a softening agent comprising 2 to 15 parts by mass of a coumarone-based resin,

based on 100 parts by mass of a rubber component comprising 70% by mass or more of a styrene-butadiene rubber having a styrene content of from 20 to 50% by mass and a vinyl content of from 15 to 65%,
M.αSiO 2 .βH 2 O  (A)

wherein in formula (A), M is an oxide or hydroxide of at least one metal selected from Al, Mg, Ti and Ca, and each of α and β is an integer of from 0 to 10.

7. The rubber composition for a tread of claim 6 , wherein the softening agent comprises 11 to 20 parts by mass of bis(2-ethylhexyl)sebacate.

8. The rubber composition for a tread of claim 6 , wherein the powder of an inorganic compound is made of aluminum oxide and/or aluminum hydroxide.

9. A tire having a tread composed of the rubber composition for a tread of claim 6 .

10. The rubber composition for a tread of claim 6 , wherein a softening point of the coumarone-based resin is 60° C. or higher.

11. The rubber composition for a tread of claim 6 , wherein a nitrogen adsorption specific surface area of the silica is 40 to 500 m 2 /g.

12. The rubber composition for a tread of claim 6 , wherein the rubber composition further comprises 1,3-diphenylguanidine and tetrakis(2-ethylhexyl)thiuram disulfide as vulcanization accelerators.

13. The rubber composition for a tread of claim 8 , wherein the softening agent further comprises 11 to 20 parts by mass of bis(2-ethylhexyl)sebacate.

Assignees

• Sumitomo Rubber Ind

Inventors

• Suzuki Yumi
• Nakazono Takeo

Classifications

• C08L45/02

  of coumarone-indene polymers · CPC title

• C08L25/00

  Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers · CPC title

• C08K5/0016

  Plasticisers · CPC title

• C08L9/00

  Compositions of homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• C08K5/11

  of acyclic polycarboxylic acids · CPC title