Block copolymers of monovinylarenes and conjugated dienes containing two interior tapered blocks
US5399628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1993 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Dec 2, 2013 |
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 monomer in the presence of a randomizer; (2) an initiator and monovinylaromatic monomer; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; (5) conjugated diene monomer; and (6) a coupling agent; and the polymodal tapered block copolymers prepared thereby. The copolymers are particularly useful neat or in blends for applications such as packaging and food or drink containers which require transparency and good environmental stress crack resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.