The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 30, 2005
Filed:
Mar. 29, 2001
Manfred Melzig, Wessling, DE;
Herbert Zinner, Pentling, DE;
Manfred Melzig, Wessling, DE;
Herbert Zinner, Pentling, DE;
Rodenstock GmbH, Munich, DE;
Abstract
A photochromic compound suitable for use as a single substance for photochromic tinting of a transparent plastic article so that the tinted article has a neutral gray or brown color in the excited state, is made by fusing at least two non-identical photochromic sections to an aromatic structure. The photochromic sections are selected so that the different absorption wavelengths of the excited photochromic sections give rise to a neutral gray or brown color in the plastic material and are selected from the group consisting of oxazines and pyrans. At least one of the photochromic sections is not an indolino spiropyran. The aromatic structure to which the photochromic sections are fused is selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene. The positions of fusion of the photochromic sections on the aromatic structure are directly adjacent to the oxygen atom of the pyran or the oxygen or nitrogen atom of the oxazine.