Tapered block copolymers of conjugated dienes and monovinylarenes
US5256736A · kind A · utility
71Cited by
9References
17Claims
0Family size
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Key dates
| Filing date | May 8, 1991 |
| Grant date | Oct 26, 1993 |
| Priority date | — |
| Expiry date | May 8, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F297/044
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for preparing tapered block copolymers in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; (3) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent to produce a polymodal tapered block copolymer. The copolymers are particularly useful for packaging applications which require good environmental stress crack resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.