Polyamide-imide solutions and the process for obtaining them
US5095070A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1991 |
| Grant date | Mar 10, 1992 |
| Priority date | — |
| Expiry date | May 17, 2011 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F6/78
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to spinnable and mouldable polyamide-imide solutions as well as the process for their preparation. They contain 4 to 35% of a polyamide-imide having a polydispersity index.ltoreq.2.1 in a solvent mixture containing 45-100% by weight of DMEU and 0-55% of an aprotic polar solvent. They are obtained by the reaction, in dimethylethyleneurea of pH.ltoreq.7 as polycondensation solvent, of a diisocyanate, an aromatic acid anhydride, optionally an alkali or alkaline earth dicarboxybenzene sulphonate and optionally another aromatic dicarboxylic acid, the polyamide-imide concentration therefore being from 4 to 35%, then by dilution in a polar solvent at a temperature of between 120.degree. and 200.degree. C. The solutions thus obtained are limpid at ambient temperature, capable of being stored and have an improved color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.