Polyetherimide preparation method including addition of macrocyclic polyetherimide oligomers
US5856421A · kind A · utility
19Cited by
4References
14Claims
0Family size
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Key dates
| Filing date | Mar 17, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Mar 17, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G73/1007
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Macrocyclic polyether oligomers, preferably as mixtures of oligomers of different degrees of polymerization, are incorporated in a direct displacement reaction mixture for the formation of polyetherimides, said reaction mixture comprising at least one alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon and at least one bis(halo- or nitrophthalimide). The macrocyclic oligomers can be isolated from an earlier-prepared linear polyetherimide composition. Their incorporation in the reaction mixture does not increase the proportion of oligomers in the polyetherimide product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.