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. 08, 1992
Filed:
Oct. 10, 1990
Alberto Vacca, Carcare, IT;
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
An improved process for preparing silver halide emulsions by precipitation of silver halide grains in a single reaction vessel comprising a dispersing medium is disclosed. The process comprises forming a silver halide emulsion by adding silver salt and halide salt solutions in a dispersing medium contained in a reaction vessel to form silver halide nuclei and allowing said silver halide nuclei to grow in said reaction vessel. The improvement comprises, during a pause of addition of silver salt and halide salt solutions, reducing the volume of silver halide emulsion by continuously delivering the silver halide emulsion to a cleaning stage for the partial removal of dispersing medium and any salt soluble therein and returning the silver halide emulsion to the reaction vessel.