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:
Sep. 09, 1997
Filed:
Dec. 01, 1995
Stewart Bennett, Concord, MA (US);
John J Cael, Mendon, MA (US);
Narendra S Kadaba, Chestnut Hill, MA (US);
Giorgio B Trapani, Cambridge, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
This invention relates to a new and improved light-polarizing sheet comprising molecularly oriented polyvinyl alcohol containing an oriented block segments of polyvinylene and said polyvinyl alcohol. In particular, the polarizing sheet comprises a polyvinylalcohol/polyvinylene block copolymer material wherein the polyvinylene blocks thereof are formed by molecular dehydration of a sheet of polyvinylalcohol; said sheet of polyvinylalcohol/polyvinylene block copolymer material comprising a uniform distribution of light-polarizing molecules of polyvinylalcohol/polyvinylene block copolymer material varying in the length, n, of the conjugated repeating vinylene unit of the polyvinylene block of the copolymer throughout the range of from 2 to 24; the concentration of each of said polyvinylene blocks, as determined by the absorption of wavelengths ranging from 200 to 700 nm remaining relatively constant, the degree of orientation of said light-polarizing molecules, as measured by the spectral dichroic ratio, R.sub.D, of said blocks, increasing throughout said range with increasing length, n, of said polyvinylene blocks; said polyvinylene block concentration and said degree of orientation of said molecules imparting to said sheet a photopic dichroic ratio, R.sub.D, of at least approximately 45.