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. 10, 2009
Filed:
Mar. 11, 2005
Djamschid Amirzadeh-asl, Moers, DE;
Jürgen Bäuml, Kamp-Lintfort, DE;
Udo Selter, Moers, DE;
Sachtleben Chemie GmbH, Duisburg, DE;
Abstract
This patent describes the use of barium sulfate as filler for thermosetting and thermoplastic plastics, elastomers, sealants, adhesives, fillers, varnishes, paints, paper, glass and as substrate for colored pigment formulations as well as for single-layer or multilayer coatings consisting of metal oxides, metal oxide mixtures and/or metal compounds, as a nucleus of crystallization for lead sulfate in the negative electrode paste of lead accumulators and as an X-ray contrast medium, the barium sulfate being produced by a continuous process wherein a barium salt solution and a sulfate solution are simultaneously and continuously brought together in equimolar quantities in a precipitating suspension at a temperature of 30 to 90° C., with constant stirring, the precipitating suspension is withdrawn continuously in a steady volume and the barium sulfate precipitate is filtered, washed and optionally dried, wherein the barium salt solution has a concentration of 0.1 to 0.8 Bamol/l and the sulfuric acid has a concentration of 0.1 to 2.0 SOmol/l, and the flow rate and stirring speed are controlled, at a constant precipitation volume, in such a way that a pH value of 1 to 5 is obtained in the precipitating suspension, and the lamellar barium sulfate particles produced as result of the precipitation are 0.1 to 50 μm wide, 0.1 to 50 μm long and 0.1 to 2 μm thick and the needle-shaped particles produced as result of the precipitation are 1 to 50 μm long and 0.1 to 2 μm thick, the ratio of length or width to the thickness being 3:1 to 500:1.