Catalytic suspension/dispersion preparation of polyamides from polyamide forming salt
US4925914A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1988 |
| Grant date | May 15, 1990 |
| Priority date | — |
| Expiry date | Aug 24, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G69/28
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention relates to a process for producing high molecular weight homopolyamides from a nylon salt formed from substantially equimolar proportions of a diamine and a dicarboxylic acid. The process comprises: (a) dispersing the nylon salt in its finely divided state having uniformly preblended therein a solid hypophosphite catalyst in a liquid aliphatic hydrocarbon, and polycondensing the dispersion either (b) at a temperature above 100.degree. C. but below the lower of the two temperatures representing the melting point of the nylon salt and the eventual polyamide product respectively where the polyamide product is a crystalline, or, (c) at a temperature up to 60.degree. C. above the glass transition temperature of the polyamide product where such product is amorphous.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.