Rubber composition comprising a styrene-butadiene block copolymer having two kinds of blocks
US4782119A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 27, 1985 |
| Grant date | Nov 1, 1988 |
| Priority date | — |
| Expiry date | Aug 27, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S525/914
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A rubber composition containing at least 20% by weight of a styrene-butadiene block copolymer consisting of a block (A) and a block (B) characterized in that: (i) the block (A) is a styrene-butadiene copolymer block having the content of styrene of 10-80% by weight and the average content of the vinyl bonds in the butadiene portion of 30-70% by weight; (ii) the block (B) is a polybutadiene block with the average content of the vinyl bonds in the butadiene portion being not more than 60% by weight (iii) the styrene-butadiene block copolymer contains at least 20% by weight of each of the block (A) and the block (B); (iv) the average content of the vinyl bonds in the butadiene portion of the block (A) is greater by at least 5% by weight than that of the block (B); (v) the glass transition temperature of the block (A) is higher by at least 30.degree. C. than that of the block (B); (vi) the whole content of the bound styrene in the above block copolymer is 5-40% by weight; (vii) the ratio Mw/Mn between the weight average molecular weight Mw and the number average molecular weight Mn of the block copolymer is 1.8-5.0 when calculated as polystyrene according to the gel permeation chromato…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.