Photochromic articles with reduced temperature dependency and methods for preparation
US7320826B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2003 |
| Grant date | Jan 22, 2008 |
| Priority date | — |
| Expiry date | Jul 27, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31993
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Described are photochromic articles that include a substrate, a temperature dependent reducing amount of at least one organic photochromic material (b) that changes from more absorbing to less absorbing of radiation in its activating spectral absorbance as the temperature increases from 10° C. to 35° C. and at least one other photochromic material (c) that is different from photochromic material (b). In the article, photochromic material (b) is interposed between photochromic material (c) and a source of activating radiation. The photochromic article demonstrates a more consistent photochromic response, for example, an optical density response loss of 50 percent or less over a temperature range of from 10° C. to 35° C. as measured in the Photochromic Temperature Dependence Test. Methods for producing the aforedescribed articles are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.