Photochromic coating exhibiting improved performance and reduced yellowness
US8512604B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 18, 2009 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Aug 18, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F222/104
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An acrylate-based optical coating composition containing a blend of monomers, a metal salt, a Hindered Amine Light Stabilizer (HALS), an antioxidant (AO), an initiator and a photochromic dye. The initiator has a range of free radical energy that is below a predetermined level. The cure process is controlled by the catalyst and initiator in combination with the HALS and AO to avoid deleterious reactions that can increase yellowness. The composition is well suited to be applied to a lens and cured in the mold to form a coating with reduced yellowness having high adhesion and abrasion-resistant properties. A photochromic segmented bifocal lens is produced with low photochromic fatigue and favorable % T values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.