Michael Julian Lubianetsky

US Patent:

6451236, Sep 17, 2002

Filed:

Feb 2, 2000

Appl. No.:

09/497073

Inventors:

Robert A. Sallavanti - Dalton PA
Michael J. Lubianetsky - Blakely PA

Assignee:

Gentex Optics, Inc. - Carbondale PA

International Classification:

B29C 7100

US Classification:

264129, 264143, 264157, 26421113, 264340

Abstract:

A method of making photochromic thermoplastic wherein the material is extruded into a length or lengths having at least one relatively small cross-sectional dimension. The length or lengths are treated with a solution of photochromic dye dissolved in a solvent, for example, cyclohexanone, which attacks the material. The length or lengths have a surface area-to-volume ratio sufficiently large to absorb an effective amount of the dye at their surface or surfaces. The length or lengths are dried to evaporate the solvent. The length or lengths are heated during the treating and drying steps. The dried length or lengths are cut into smaller pieces which may be introduced directly into a molding machine to form photochromic articles. Where a plurality of lengths are provided, the surfaces thereof are maintained separated from one another during the treating and drying steps.

US Patent:

52718727, Dec 21, 1993

Filed:

Jul 21, 1992

Appl. No.:

7/917914

Inventors:

Robert A. Sallavanti - Dalton PA
Michael J. Lubianetsky - Blakely PA

Assignee:

Gentex Corporation - Carbondale PA

International Classification:

F21V 900
F21V 904
G02B 522

US Classification:

252582

Abstract:

An optical filter for absorbing neodymium YAG-doubled laser radiation at 532 nanometers, comprising a polymeric matrix of transparent polycarbonate containing platinum deuteroporphyrin IX dimethyl ester, has an optical density of 1. 8 at 532 nm while having a photopic luminous visible transmission of 53. 8%. Optionally, the filter may contain other additives for absorption at other laser wavelengths, such as vanadyl tetra-4-tert-butylphthalocyanine for absorption of ruby laser radiation at 694 nanometers and tris(p-diethylaminophenyl)aminium hexafluoroantimonate for absorption of neodymium YAG laser radiation at 1064 nanometers.