Method for producing rubber composition

Patent metadata

Field	Value
Publication number	US-9796818-B2
Application number	US-201615158659-A
Country	US
Kind code	B2
Filing date	May 19, 2016
Priority date	May 21, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A method for producing a rubber composition, which comprises kneading 20 parts by mass or more of silica with 100 parts by mass of diene rubber, and adding from 3 to 20 parts by mass of syndiotactic-1,2-polybutadiene to the kneaded mixture obtained, followed by kneading is disclosed. This method brings out characteristics of syndiotactic-1,2-polybutadiene and can improve wet grip performance.

First claim

What is claimed is:

1. A method for producing a rubber composition, comprising kneading 20 parts by mass or more of silica with 100 parts by mass of diene rubber to form a kneaded mixture, and adding from 3 to 20 parts by mass of syndiotactic-1,2-polybutadiene to the kneaded mixture obtained, followed by kneading.

2. The method for producing a rubber composition according to claim 1 , wherein the syndiotactic-1,2-polybutadiene has a melting point of 110° C. or lower.

3. The method for producing a rubber composition according to claim 1 , wherein the diene rubber is such that the content of a vinyl bond unit in the entire polymer constituting the diene rubber is from 10 to 25 mass %.

4. The method for producing a rubber composition according to claim 1 , wherein the kneaded mixture is prepared by kneading the entire amount of silica to be contained in the rubber composition with the diene rubber.

5. The method for producing a rubber composition according to claim 1 , wherein the diene rubber comprises a modified diene rubber modified with a functional group having an interaction with a silanol group on a silica surface.

6. The method for producing a rubber composition according to claim 1 , wherein the syndiotactic-1,2-polybutadiene has a 1,2-vinyl bond content of 70 mol % or more and the degree of crystallinity of from 5 to 50%.

7. The method for producing a rubber composition according to claim 1 , wherein the kneaded mixture is prepared without adding syndiotactic-1,2-polybutadiene in the step of kneading the silica with the diene rubber.

8. The method for producing a rubber composition according to claim 1 , further comprising adding a vulcanizing agent and a vulcanization accelerator to a second kneaded mixture obtained by adding the syndiotactic-1,2-polybutadiene to the kneaded mixture.

9. The method for producing a rubber composition according to claim 1 , wherein a vulcanizing agent and a vulcanization accelerator are added to the kneaded mixture together with the syndiotactic-1,2-polybutadiene followed by kneading.

10. The method for producing a rubber composition according to claim 1 , wherein the syndiotactic-1,2-polybutadiene is phase-separated as a disperse phase from the diene rubber constituting a continuous phase in the rubber composition obtained.

11. A method for manufacturing a pneumatic tire, comprising:
kneading 20 parts by mass or more of silica with 100 parts by mass of diene rubber to form a kneaded mixture,
adding from 3 to 20 parts by mass of syndiotactic-1,2-polybutadiene to the kneaded mixture obtained, followed by kneading to obtain a rubber composition,
manufacturing an unvulcanized tire using the rubber composition, and vulcanization-molding the unvulcanized tire.

Assignees

• Toyo Tire & Rubber Co

Inventors

• Takahashi Hiroyuki

Classifications

• C08J2309/06

  Copolymers with styrene · CPC title

• C08J2409/06

  Copolymers with styrene · CPC title

• C08L9/06 Primary

  Copolymers with styrene · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08J3/203 Primary

  Solid polymers with solid and/or liquid additives · CPC title