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:
Nov. 14, 1989
Filed:
Oct. 15, 1987
Cletus N Welch, Clinton, OH (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
Described is a method for imparting a photochromic response to a synthetic plastic article, e.g., an optical lens such as a sunglass lens prepared from an allyl diglycol carbonate monomer. The method described comprises depositing a thin uniform substantially dry film of a photochromic-bearing polymeric resin onto at least one planar surface of the synthetic plastic material, heating the plastic article and resin film substantially uniformly at temperatures near to but below the melting temperature of the photochromic substance for a time sufficient to transfer a photochromic amount of the photochromic material into the subsurface region of the plastic article, and thereafter removing the photochromic-lean resin film from the planar surface(s) of the plastic article.