Stabilized photochromic materials
US4166043A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1974 |
| Grant date | Aug 28, 1979 |
| Priority date | — |
| Expiry date | Dec 23, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31511
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Organic photochromic materials comprising a photochromic dye and a resinous material can be stabilized with a protective coating which will protect them from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful organic photochromic dyes include the spiropyrans, the spirooxazines, the metal dithizonates, the phenazines, the phenothiazines and other known photochromic compositions. Useful resinous materials include vinyl-type thermoplastics, cellulosic materials, polyesters, epoxy resins and aminoplast resins. The encapsulated photochromic materials of the invention comprise an organic photochromic dye in combination with an organic resinous material enclosed within an outer shell of an inorganic material and find use in the preparation of photochromic plastic films, sheets, ophthalmic lenses such as lenses for sunglasses and in camera lenses and filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.