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:
Oct. 30, 1984
Filed:
Aug. 02, 1982
Applicant:
Inventors:
Robert W Ashcraft, Towanda, PA (US);
Rusty E Koenigkramer, Towanda, PA (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430510 ; 430523 ; 523351 ; 524503 ; 525 56 ;
Abstract
In preparing an opaque backing layer for a photographic film, superior covering power and coating dispersion stability are obtained by (1) dispersing carbon black in a minor phase of polyvinyl pyrrolidone/vinyl acetate copolymer before addition of a major phase of polyvinyl alcohol, and (2) delaying the addition of surfactant or coating aids until after complete mixing of the polyvinyl alcohol with the solid carbon black dispersion. This coating dispersion is particularly useful for the preparation of a dischargeable opaque backing layer for a diffusion transfer film element.