Method for preparing cyclic polyarylate oligomers
US4927904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1989 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Jun 12, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/87
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Cyclic polyarylate oligomer compositions are prepared by the reaction of an aromatic dicarboxylic acid halide, such as isophthaloyl chloride or terephthaloyl chloride, with a water-soluble salt of a dihydroxyaromatic compound, such as bisphenol A disodium salt. Freshly prepared solutions of the halide in an organic liquid such as methylene chloride, and of the salt in water, are simultaneously introduced into an organic liquid containing a catalytic amount of at least one quaternary ammonium salt having a single alkyl group containing about 8-20 carbon atoms and having not more than 5 additional carbon atoms. The dihydroxyaromatic compound salt is employed in the amount of at least about 3% in excess of stoichiometric.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.