Method for preparing photochromic plastic article
US5130353A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1990 |
| Grant date | Jul 14, 1992 |
| Priority date | — |
| Expiry date | Mar 7, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L1/284
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for incorporating by thermal diffusion a photochromic substance into a synthetic organic host material is described. In the process, a surface of the host material containing a coating of a resin composition of from about 5 to about 50 parts of hydroxy (C.sub.2 -C.sub.3) alkyl cellulose, e.g., hydroxy propyl cellulose, and from about 95 to about 50 parts of poly(vinylpyrrolidone), which resin composition contains a photochromic substance, is heated to diffuse at least a portion of the photochromic substance into the surface of the host material. Subsequently, the coating is removed by washing with warm soapy water. In a particular embodiment, the host material is a polymer prepared from diethylene glycol bis(allyl carbonate).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.