Process for depolymerizing polycaprolactam processing waste to form caprolactam
US5869654A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Apr 18, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D201/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides an improved process for the recovery of caprolactam from polycaprolactam processing waste. The present process for depolymerizing polycaprolactam waste to form caprolactam comprises the step of: in the absence of added catalyst, contacting the polycaprolactam waste with superheated steam at a temperature of about 250.degree. C. to about 400.degree. C. and at a pressure within the range of about 1.5 atm to about 100 atm and substantially less than the saturated vapor pressure of water at the temperature wherein a caprolactam-containing vapor stream is formed. The formed caprolactam may then be used in the production of engineered resins and fibers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.