Photochromic polyurethane coating and articles having such a coating
US6187444A · kind A · utility
163Cited by
21References
38Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 22, 1998 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | May 22, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31855
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Described are photochromic polyurethane coatings that meet commercially acceptable "cosmetic" standards for optical coatings. Also described are articles having such coatings. The coatings exhibit a Fischer microhardness of from 50 to 150 Newtons per mm.sup.2 and improved photochromic properties, i.e., the formation of darker activated colors and faster rates of photochromic activation and fade when irradiated with ultraviolet light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.