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. 06, 1994
Filed:
Dec. 23, 1993
William H Pope, Sandersville, GA (US);
Michael W Ginn, Wrightsville, GA (US);
R Brock McNeely, Davisboro, GA (US);
ECC International Inc., Atlanta, GA (US);
Abstract
A method for producing calcined kaolin pigments of high opacifying properties and low abrasion. A kaolin crude is selected having a G.E. brightness in the range of 70 to 80, a titania content of 2.0 to 3.0% by weight, less than 2% iron expressed as Fe.sub.2 O.sub.3, and a particle size distribution such that at least 88% by weight of the particles of said crude are of less than 2 .mu.m E.S.D.. The crude is blunged with water, and the resultant slurry degritted to form an aqueous slurry having at least 65% by weight solids. The slurry is centrifuged and a fraction recovered having over 65% solids, and in which at least 92% by weight of the particles are of less than 2 .mu.m. The recovered fraction is dried to less than 1% moisture, and pulverized to break up agglomerates. The pulverized fraction is then calcined by heating same to 1450.degree. to 1600.degree. F. after which the calcined kaolin is milled to yield a product having a G.E. brightness of 79 to 81 and an Einleiner abrasion of not mere than 2.5 mg wt loss.