Photochromic pyran compounds

US6683709B2 · kind B2 · utility

Assignee

• RODENSTOCK GMBH · DE

Inventors

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

Key dates

• Filing date: Feb 7, 2002
• Grant date: Jan 27, 2004
• Expiry date: Feb 7, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D311/92
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Photochromic pyran compounds and their use in synthetic resin objects of all types, especially for ophthalmic applications, particularly spiro compounds having a fluorene structure derived from naphthopyrans, which are known as spirofluorenopyrans. By introducing respectively only one strongly electron donating or withdrawing group at specific positions in the periphery of the pyran dye, photochromic compounds obtained which in the excited state are distinguished by an expanded color spectrum, while simulataneously offering comparably good bleaching rates and good durability.