Patents by Inventor Akira Takeshi

Akira Takeshi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Calcium carbonate in a platelet-like particulate form and a method for the preparation thereof
    Patent number: 5075093
    Abstract: The invention provides a method for the preparation of a calcium carbonate powder of which the particles have a platelet-like particulate configuration and which is useful as a pigment or filler in various products with superiority to kaolin clays and mica powders. The method is a two-step carbonation method of a milk of lime of which the first step is performed by blowing carbon dioxide into the milk of lime until 10 to 70% of the calcium hydroxide is carbonated and the second step is performed by admixing the thus partially carbonated milk of lime with an aqueous carbonating solution containing an alkali metal carbonate or ammonium carbonate and an alkali metal hydroxide or ammonium hydroxide in specified concentrations to complete the carbonation of the calcium hydroxide.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: December 24, 1991
    Assignee: Okutama Kogyo Kabushiki Kaisha
    Inventors: Hiroichi Tanaka, Masanori Matsukawa, Akira Takeshi