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:
Dec. 22, 1998
Filed:
Nov. 14, 1997
Applicant:
Inventors:
Amitava Gupta, Bethesda, MD (US);
Ronald D Blum, Roanoke, VA (US);
Venkatramani S Iyer, Roanoke, VA (US);
Assignee:
Innotech, Inc., Roanoake, VA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B05D / ;
U.S. Cl.
CPC ...
427162 ; 252586 ; 427384 ; 4274301 ; 427565 ;
Abstract
The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.