Method for impregnating a thermoplastic polymer
US4678684A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 21, 1986 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Mar 21, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249997
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Disclosed is a method for impregnating a thermoplastic polymer with an impregnation material such as a fragrance or pest control agent or pharmaceutical composition. A thermoplastic polymer is impregnated by (1) dissolving an impregnation material such as a fragrance or pest control agent or pharmaceutical composition material in a volatile swelling agent maintained at or near supercritical conditions for the volatile swelling agent, (2) swelling the thermoplastic polymer by contacting it at or near supercritical conditions for the volatile swelling agent with the impregnation material-laden volatile swelling agent and then (3) reducing the pressure so that the volatile swelling agent diffuses out of the thus impregnated thermoplastic polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.