Spirofluorenopyrans

US6315928A · kind A · utility

Assignee

• Optische Werke G. Rodenstock · DE

Inventors

• Claudia Mann · Munich, DE
• Manfred Melzig · Weßling, DE
• Udo Weigand · Munich, DE

Key dates

• Filing date: Mar 2, 2001
• Grant date: Nov 13, 2001
• Expiry date: Mar 2, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B5/23
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to specific photochromic 3H-naphtho[2,1-b]pyran derivatives and to their use in plastics of all types, especially for ophthalmic purposes. In particular, the present invention relates to spiro compounds derived from naphthopyrans and having a fluorene structure, referred to as spirofluorenopyrans, in which an annelated ring system is joined by a spiro bond to the central carbon atom of the fluorene structure.