Capped photochromic silver halides for incorporation into a plastic matrix
US5252450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1991 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Feb 6, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K9/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A photochromic composition for incorporation into a light-transmitting polymer is described. Silver halide crystallites are capped with an organic capping group using multivalent metal ions integrated into the surface of the silver halide crystallite to provide crystallite surface sites that provide a handle between the organic capping group and the silver halide crystallites. The size of the capped silver halide crystallites are less than about 1000 .ANG.. A reverse micelle technique is used to control the size of the silver halide crystallite while integrating the multivalent ions and bonding the organic capping group. The capped crystallites are soluble in organic solvents and, as such, are readily incorporated into a polymer matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.