Process for subsequent condensation of polycondensates, in particular of polyamide 6.6
US5859177A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1997 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Aug 26, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2377/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The process for single-stage postcondensation of a polycondensate in a fluidized bed reactor (1) includes feeding the polycondensate through the fluidized bed reactor (1); circulating a main stream of nitrogen carrier gas through the fluidized bed reactor; withdrawing a fractional stream at a temperature of from 20.degree. to 230.degree. C. from the main stream of the nitrogen carrier gas; passing the fractional stream through a water-filled gas scrubber column (15) so as to form a conditioned stream of the nitrogen carrier gas with a predetermined dew point between 10.degree. to 80.degree. C.; and returning the conditioned stream to the main stream. In preferred embodiments the polycondensate is allowed to cool during a cool-down stage at an end of the postcondensation and the withdrawal of the fractional stream from the main stream is halted, but the circulating of the main stream through the fluidized bed reactor is continued during the cool-down stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.