Transparent block copolymers having two monovinyl-substituted aromatic blocks of different molecular weight
US4939208A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1987 |
| Grant date | Jul 3, 1990 |
| Priority date | — |
| Expiry date | Dec 3, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L53/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Transparent linear resinous conjugated diene/monovinyl-substituted aromatic block copolymers of improved properties are prepared by forming a monovinyl-substituted aromatic homopolymer block referred to as S.sub.1, followed by forming a conjugated diene homopolymer block, referred to as B.sub.1 and linked to segments S.sub.1, followed by the formation of a conjugated diene/monovinyl-substituted aromatic random copolymer block, referred to as B/S and linked to segment B.sub.1, followed by the formation of a monovinyl-substituted aromatic homopolymer block, referred to as S.sub.2 and linked to segment B/S thereby forming the block copolymer S.sub.1 -B.sub.1 -B/S-S.sub.2 wherein the molecular weight of the S.sub.2 block is significantly greater than the molecular weight of the S.sub.1 block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.