JP2010018691A5 - - Google Patents

Description

In this pre-mixing process, SBR is modified by reacting SBR with a diene rubber containing SBR, a modifier and an organic peroxide, an azo initiator, or a radical generator that uses carbon black. Under stirring conditions such as 140 ° C. or higher, more preferably 160 to 200 ° C. (180 ° C. in the examples), the mercapto group or the disulfide bond moiety reacts with the vinyl group in the SBR. An amino group is introduced into the main chain, that is, the main chain of the polymer molecule can be modified by premixing with respect to SBR in which the main chain is unmodified.

The silane coupling agent has a general formula
(R ′) _3-n (OR) _n SiR ″ SxR ″ Si (OR) _n (R ′) _3-n
R: an alkyl group having 1 to 3 carbon atoms
R ′: an alkyl group having 1 to 3 carbon atoms
R ″: an alkylene group having 1 to 5 carbon atoms
X: 2-4
n: 1 to 3
In represented, polysulfide silane coupling agent having a sulfur chain which reacts with the alkoxysilyl group and the polymer capable of reacting with silanol groups of the silica surface is used. Specifically, for example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) ) Disulfide and the like are preferably used.

A specific polyfunctional group-containing disulfide compound is premixed at a temperature of 20 to 135 ° C. with a silica-containing diene rubber composition containing the above components as essential components, ie, a diene rubber containing 50% by weight or more of natural rubber. after silica in the composition obtained by mixing the formulations which are generally used as a blending agent for rubber, for example, reinforcing agents or fillers are represented by carbon black, sulfur, etc. according to the type of diene rubber Vulcanizing accelerators, thiazole-based, sulfenamide-based, guanidine-based, thiuram-based vulcanizing accelerators, processing aids such as stearic acid, paraffin wax, aroma oil, anti-aging agents, plasticizers, etc. Used.

Example 1
In Comparative Example 1, first, natural rubber and disulfide compound SS were premixed for 1 minute at 80 ° C. using a Banbury mixer, and then the components other than sulfur and vulcanization accelerator were mixed, and then sulfur and Vulcanization accelerators were mixed using open rolls.
SS: Ouchi Emerging Chemical Industry Product Knocker SS
o, o′-Dibenzamide diphenyl disulfide

Comparative Example 2, Examples 10-11
In Comparative Example 1 and Example 1, the silica content was changed to 38 parts by weight, and the silane coupling agent content was changed to 6 parts by weight. Furthermore, in Examples 10 to 11 in which the premixing temperature was changed to 70 ° C. , various disulfide compounds were used in predetermined amounts.

Comparative Example 4 and Example 14
In Comparative Example 1 and Example 1, 20 parts by weight of 100 parts by weight of natural rubber were replaced with SBR (Nippon Zeon product Nipol 1502). Furthermore, in Example 14 in which the premixing temperature was changed to 100 ° C., 0.80 part by weight of DTS was used as the disulfide compound.

Comparative Example 5 and Example 15
In Comparative Example 1 and Example 1, 40 parts by weight of 100 parts by weight of natural rubber were replaced with SBR (Nipol 1502). Furthermore, in Example 15 in which the premixing temperature was changed to 100 ° C., 0.80 part by weight of DTS was used as the disulfide compound.