Method for preparing brominated polycarbonates, and products obtained thereby
US5977265A · kind A · utility
2Cited by
5References
24Claims
0Family size
Assignee
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Key dates
| Filing date | Sep 2, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Sep 2, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
High flow brominated polycarbonates, useful as flame retardant additives for other polymers such as polyesters, are obtained by equilibration of a brominated aromatic polycarbonate such as a tetrabromobisphenol A homo- or copolycarbonate with a di- or polyhydroxy aromatic compound such as bisphenol A, or a diaryl carbonate, and an equilibration catalyst, under conditions such that the weight average molecular weight of the brominated polycarbonate is reduced by at least 35%. Preferred equilibration catalysts are Group I metal carboxylates, such as sodium stearate, and hexaalkylguanidinium salts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.