Photochromic composition
US5462698A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Mar 31, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/733
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A photochromic composition comprising (A) 100 parts by weight of a compound having at least one epoxy group in the molecule and (B) 0.0001 to 10,000 parts by weight of a photochromic compound. The compound (A) is represented by the following general formula ##STR1## wherein A is a residue of an n-valent alcoholic hydroxyl-containing compound, a residue of an n-valent phenolic-hydroxyl-containing compound, or a residue of an n-valent carboxylic acid, R.sup.1 is a hydrogen atom or a methyl group, and n is an integer of 1 to 4. Examples of the (B) photochromic compound include fulgide compounds, spirooxazine compounds and chromene compounds. A polymer obtained by polymerizing the above photochromic composition of the invention by a radical polymerization method has a good durability of photochromic properties, and also possesses a dark color-forming density, a fast color fading speed, is transparent, and has a high surface hardness. Thus, especially, the polymer is suitable for use as a photochromic lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.