Rubber compounds containing silicon dioxide for the production of tyres

Patent metadata

Field	Value
Publication number	US-9896568-B2
Application number	US-201515318199-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Jun 13, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A method for preparing a rubber compound comprising at least one first mixing step in which at least part of a cross-linkable polymer base is mixed at least with a reactive reinforcing filler, a dendrimer functionalized with polar groups adapted to interact with the reactive reinforcing filler and a nucleophile agent; and a subsequent mixing step in which the compound being prepared is mixed with a vulcanization system.

First claim

The invention claimed is:

1. A method for preparing a rubber compound; said method comprising a first mixing step, during which at least part of a cross-linkable polymer base is mixed with silicon dioxide, a dendrimer functionalized with polar groups suited to interact with the silicon dioxide, and a nucleophile agent; and a successive mixing step, during which the rubber compound being prepared is mixed with a vulcanization system; said method comprising an intermediate mixing step between said first mixing step and said successive mixing step and during which the rubber compound being prepared is mixed with at least one silane bonding agent; a fraction of the cross-linkable polymer base ranging from 20 to 80% by weight of the overall cross-linkable polymer base being added during the first mixing step, and the remaining part of the cross-linkable polymer base being added during the intermediate mixing step.

2. The method according to claim 1 , wherein said dendrimer is functionalized with polar groups selected from the group consisting of carboxyls, carbonyls, hydroxyls, isocyanates, amines, amides, esters, trialkoxysilanes, acrylates, methacrylates and polyethylene oxides.

3. The method according to claim 1 , wherein the dendrimer functionalized with polar groups is available in the rubber compound in a quantity ranging from 1 to 50 phr.

4. The method according to claim 1 , wherein the nucleophile agent is added during the first mixing step in a quantity ranging from 0.6 to 5 phr.

5. The method according to claim 1 , wherein the nucleophile agent comprises guanidines or sulfenamides.

6. The method according to claim 1 , wherein the nucleophile agent is selected from the group consisting of diphenyl guanidine (DPG), mercapto benzothiazole disulfide (MBTS), N-tert-butyl-2-benzothiazyl-sulfenamide (TBBS), tetrabenzyl thiuram disulfide (TBzTD), and benzothiazyl-cyclohexyl-sulfenamide (CBS).

7. The method according to claim 1 , wherein the cross-linkable polymer base is selected from the group consisting of styrene-butadiene rubber, butyl rubber, natural rubber, isoprene rubber and mixtures thereof.

8. The method according to claim 1 , wherein a fraction of silicon dioxide ranging from 10 to 80% by weight of the overall silicon dioxide is added during the first mixing step, and the remaining part of silicon dioxide is added during the intermediate mixing step.

Assignees

• Cossu Giancarlo
• Agoretti Pasquale
• Bridgestone Corp

Inventors

• Cossu Giancarlo
• Agoretti Pasquale

Classifications

• C08L9/06 Primary

  Copolymers with styrene · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08J2409/00

  Characterised by the use of homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• C08J2309/06

  Copolymers with styrene · CPC title