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. 07, 1993
Filed:
Mar. 20, 1991
Applicant:
Inventor:
Clifford E Milner, Rochester, NY (US);
Assignee:
E. I. DuPont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08K / ;
U.S. Cl.
CPC ...
524413 ; 524430 ;
Abstract
This invention relates to the preparation of antihalation layers for photographic film. The invention is an improved process for the preparation of colloidal manganese dioxide dispersions adapted for use in antihalation layers, the process comprising adding a reducing agent to an aqueous solution comprising a water soluble permanganate salt and a dispersing agent, the improvement wherein said dispersing agent is a water soluble polymer selected from the group consisting of water soluble carboxylated acrylic polymers, water soluble styrene/acrylic copolymers, and water soluble alpha-methyl styrene/acrylic copolymers.