Polymerization process and polymer produced thereby
US3953543A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1973 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | Dec 26, 1993 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F297/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The process disclosed herein involves the preparation of butadiene-styrene copolymers of improved green strength and low running temperature when used in tire compositions, which comprises the steps of polymerizing a mixture of butadiene and styrene in a hydrocarbon solvent having a lithium alkyl initiator therein while the monomer mixture is fed into the polymerization system at a rate slow enough to effect random copolymerization in the resulting polymer backbone, effecting a high degree of branching by conducting the polymerization at a temperature of 90.degree.-175.degree. C. (190.degree.-347.degree. F.) and effecting the final 10-50 percent of the polymerization with a monomer portion containing a higher proportion of styrene than is incorporated into the polymer-backbone, thereby effecting the formation of block polystyrene at the terminals of a plurality of branches. This copolymer of improved green strength and low running temperature is very useful in tire compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.