Process of integrating a photochromic substance into an ophthalmic lens and a photochromic lens of organic material
US4286957A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 10, 1979 |
| Grant date | Sep 1, 1981 |
| Priority date | — |
| Expiry date | Jan 10, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C7/102
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process of integrating a photochromic substance, especially a spiropyran or a metal dithizonate, into a transparent substrate of polymerized organic material such as poly [ethylene glycol di-allyl di-carbonate] by thermal transfer, comprising applying the photochromic substance alone or with a solvent and/or thickening agent to the surface of a transparent organic substrate such as a lens disc, and heating until the photochromic substance is sublimed and then diffused and anchored in the organic material of the lens, preferably just beneath the surface to which it is applied. Preferably, the photochromic substance is initially carried on a temporarily support for application.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.