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:
Mar. 19, 1991
Filed:
Jul. 20, 1989
Eka Nobel AB, Surte, SE;
Abstract
The invention relates to a process for the preparation of an acid-resistant coating and calcium carbonate particles, in which process a slurry of calcium carbonate particles is mixed simultaneously with the solution of a zinc compound and a solution of a silica-containing substance at a temperature of 70.degree.-95.degree. C., the pH being maintained at 8-11. The invention also relates to calcium carbonate particles having an acid-resistant coating in accordance with the above-mentioned process. In addition, the invention relates to the use of calcium carbonate particles having a acid-resistant coating in accordance with the above-mentioned process, as an acid-resistant filler in the production of paper at pH 4.0-7.0.