Wire coat rubber composition for a tire and a tire comprising a wire coat rubber composition

Patent metadata

Field	Value
Publication number	US-11459447-B2
Application number	US-202016903502-A
Country	US
Kind code	B2
Filing date	Jun 17, 2020
Priority date	Jun 21, 2019
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

In accordance with the invention a wire coat rubber composition for a tire comprises from 70 phr to 100 phr of cis 1,4-polyisoprene rubber, from 0 phr to 30 phr of solution styrene butadiene rubber, from 65 phr to 95 phr pre-silanized precipitated silica, from 0.1 phr to 5 phr of a cobalt salt, up to 15 phr carbon black, up to 10 phr of a resin, and up to 10 phr oil. Further the present invention is directed to a tire comprising such a wire coat composition.

First claim

The invention claimed is:

1. A wire coat rubber composition for a tire, the rubber composition comprising: 75 phr to 90 phr of cis 1,4-polyisoprene rubber, from 10 phr to 25 phr of solution-polymerized styrene-butadiene rubber, from 65 phr to 95 phr of pre-silanized precipitated silica, from 0.1 phr to 5 phr of a cobalt salt, from 0 phr to 15 phr carbon black, from 0 phr to 10 phr of a resin, and from 0 phr to 10 phr oil, wherein the pre-silanized precipitated silica has a CTAB adsorption surface area which is within the range of 130 m 2 /g to 210 m 2 /g, wherein the solution-polymerized styrene-butadiene rubber has a glass transition temperature which is within the range of −30° C. and −90° C., and wherein the solution-polymerized styrene-butadiene rubber is tin-coupled or thio-functionalized.

2. The wire coat rubber composition of claim 1 , wherein the solution-polymerized styrene-butadiene rubber has a bound styrene content which is within the range of 10% to 20%, and a vinyl content which is within the range of 20% to 40%.

3. The wire coat rubber composition of claim 1 , wherein the solution-polymerized styrene-butadiene rubber has a glass transition temperature which is within the range of −50° C. and −70° C. and wherein the solution-polymerized styrene-butadiene rubber is tin-coupled.

4. The wire coat rubber composition of claim 1 , wherein the solution-polymerized styrene-butadiene rubber is functionalized for improved compatibility with silica, and wherein the solution-polymerized styrene-butadiene rubber is thio-functionalized.

5. The wire coat rubber composition of claim 1 wherein the pre-silanized precipitated silica is present at a level which is within the range of from 70 phr to 90 phr.

6. The wire coat rubber composition of claim 1 , wherein said pre-silanized precipitated silica is precipitated silica pre-reacted with a silica coupler comprised of bis(3-triethoxysilylpropyl)polysulfide containing an average of from 1 to 5 connecting sulfur atoms in its polysulfidic bridge or an alkoxyorganomercaptosilane.

7. The wire coat rubber composition of claim 1 , wherein said pre-silanized precipitated silica is pre-hydrophobated by treating silica with both an organomercaptosilane and an alkylsilane at a weight ratio of said organomercaptosilane to said alkylsilane which is within the range of from 10/90 to 90/10; wherein said alkylsilane is of the general Formula):X n —Si—R 4-n , wherein R is an alkyl radical having from 1 to 8, carbon atoms, wherein n is a numeral from 1 to 3, and X is a halogens or an alkoxy radical of the formula: R 1 O—, wherein R 1 is an alkyl radical having from 1 to 3 carbon atoms; and where said organomercaptosilane is of the general formula: (X) n (R 2 O) 3-n —Si—R 3 —SH), wherein X is a halogen, wherein R 2 is an alkyl radical containing from 1 to 4 carbon atoms, and R 3 is an alkylene radical containing from 1 to 4 carbon atoms, and wherein n represents an integer from 0 to 3.

8. The wire coat rubber composition of claim 1 , wherein the cobalt salt is present at a level which is within the range of 0.2 phr to 2 phr.

9. The wire coat rubber composition of claim 1 , wherein the carbon black is present at a level of less than 3 phr.

10. The wire coat rubber composition of claim 1 , wherein the level of resin in the composition is less than 5 phr.

11. The wire coat rubber composition of claim 1 , wherein the wire coat rubber composition contains less than 5 phr oil.

12. The wire coat rubber composition of claim 1 further comprising from 1 to 15 phr of sulfur.

13. The wire coat rubber composition of claim 1 , further comprising from 1 to 20 phr of zinc oxide.

14. A tire comprising a ply or a ply strip, wherein the ply or the ply strip is comprised of wires which are coated with the wire coat rubber composition according to claim 1 .

Assignees

• Goodyear Tire & Rubber

Inventors

• Tahon Julia Martine Francoise Claudine
• Bethea Robert Anthony
• Golden James Joseph
• Welter Carolin Anna
• Kaes Christian Jean-Marie

Classifications

• B29D2030/383

  Chemical treatment of the reinforcing elements, e.g. cords, wires and filamentary materials, to increase the adhesion to the rubber · CPC title

• C08L2203/202

  use in electrical wires or wirecoating · CPC title

• C08L7/00 Primary

  Compositions of natural rubber · CPC title

• B60C9/0007

  Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal · CPC title

• B60C1/0041

  Compositions of the carcass layers · CPC title