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. 06, 1977
Filed:
Aug. 24, 1976
Johan Jozef Einerhand, Maastricht, NL;
Gerardus Johannes Colbers, Maastricht, NL;
Wilhelmus Martha Huck, Elsloo, NL;
Herman Jozef Geurts, Kerkrade, NL;
Hercules Incorporated, Wilmington, DE (US);
Abstract
A process for the production of lead sulfochromate or lead chromate-sulfate-molybdate type pigments having a low content of acid soluble lead, good color and tinting properties and excellent resistance to industrial environments is described. The process comprises forming the desired lead chromate-containing precipitate in acidic aqueous medium containing chloride ions and a specified excess of lead ions in the absence of a pH buffering agent, coating the precipitate with a silicon and antimony compound, adjusting the pH of the medium to below 7 and recovering the coated precipitate as a pigment.