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. 17, 2009
Filed:
Feb. 14, 2002
Christian Richard, Chambery, FR;
Christian Richard, Chambery, FR;
Arjowiggins, Issy les Moulineaux, FR;
Abstract
The invention relates to a method for producing a sheet of paper () comprising paper fibres and calcium carbonate mainly in the form of calcite crystals linked directly to the paper fibres. The inventive method is characterised in that it comprises the following steps:—(i) an aqueous composition comprising calcium bicarbonates () and/or hydrated and/or dissolved carbon dioxide () and (ii) an aqueous composition comprising calcium hydroxide () are mixed in an aqueous medium in such a way as to precipitate the calcium carbonate in the form of vaterite crystals;—paper fibres (') are immediately added;—the vaterite crystals are left to transform into calcite crystals on contact with the fibres;—said mixture containing the calcite crystals which are fixed to the fibres is subsequently sent on the conveying wire of the papermaking machine (M) for drainage and so that the sheet of paper can be formed;—the sheet of paper () thus obtained is treated, if necessary, and dried.