Styrene-butadiene copolymer rubber composition
US4575534A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 6, 1984 |
| Grant date | Mar 11, 1986 |
| Priority date | — |
| Expiry date | Apr 6, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L21/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed herein is a rubber composition comprising at least 20% by weight of styrene-butadiene copolymer based on the total weight of the rubber content. The styrene-butadiene copolymer is obtained by randomly copolymerizing styrene with 1,3-butadiene in a hydrocarbon solvent in the presence of an organolithium compound as an initiator and then subjecting to a coupling reaction with a polyfunctional coupling agent, and contains 30-70% by weight of branched polymers therein, and has the following properties: PA0 (a) a content of bound styrene in the copolymer 3-15% by weight; PA0 (b) a content of vinyl bonds contained in the butadiene units is 15-30% by weight; PA0 (c) a Mooney viscosity (ML.sub.1+4.sup.100.degree. C.) is 15-50; and PA0 (d) a molecular weight distribution of the copolymer is bimodal at a ratio Mw/Mn of 1.4-2.2 in which Mw is a weight-average molecular weight and Mn is a number-average molecular weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.