Photochromic optical article comprising a saturated photochromic coating and a film absorbing UV radiation
US8684524B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2010 |
| Grant date | Apr 1, 2014 |
| Priority date | — |
| Expiry date | Oct 12, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02C2202/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to a photochromic optical article with reduced thermal dependency, comprising: (a) a transparent substrate, (b) a saturated photochromic layer having, in the activated state and at a temperature of 20° C. or greater, a relative transmission factor of less than 1% in the visible range, and (c) an anti-UV coating of plastic material at least partially covering the saturated photochromic layer, the said anti-UV coating containing at least one agent which absorbs UV radiation (anti-UV agent) and is distributed in a pattern consisting of a multitude of points, each having a surface area of less than 0.15 mm 2, the average distance between two neighboring points lying between 0.5 and 2 mm and the ratio of the overall surface area of all the points to the total surface area of the anti-UV coating being such that the relative transmission factor of the optical article in the visible range in the activated state and at 20° C. or greater is at least equal to 5%. The invention also relates to two methods for manufacturing such an optical article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.