Photochromic polymeric article
US4994208A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1989 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | Apr 18, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S525/92
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A photochromic article having improved photochromic equilibrium response is described. In particular, a photochromic compound is incorporated into or applied to an article, e.g., matrix, of a synthetic organic resin prepared from a composition comprising from about 55 to about 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), from about 10 to about 40 weight percent of an aliphatic polyurethan having terminal ethylenic unsaturation, e.g., an aliphatic polyesterurethan diacrylate, and from about 0 to about 5 weight percent of a difunctional monomer selected from the group consisting of allyl methacrylate and allyl acrylate. Such photochromic articles have an improved photochromic equilibrium response at ambient temperatures compared to the response of a comparable photochromic article prepared from a polyol(allyl carbonate) homopolymer, e.g., homopolymers of diethylene glycol bis(allyl carbonate), at the same ambient temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.