Patents by Inventor Chikao Yokokawa

Chikao Yokokawa 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).

  • Patent number: 6139612
    Abstract: An improved asphalt mix and a process for making the same are disclosed. The asphalt mix includes aggregate grains and additive oil. The aggregate grains are obtained from crushing recycled asphalt concrete at an ambient temperature to such an extent that each aggregate grain will retain asphalt on its surface. The additive oil is preferably hydrocarbon oil having a low vapor pressure so as to be practically nonvolatile at ambient temperatures. The additive oil also has mutual solubility with asphalt at ambient temperatures. When the aggregate grains and the additive oil are mixed together at an ambient temperature, the asphalt on the surfaces of aggregate grains swells by absorbing the oil, so that the asphalt on the grains will amalgamate together when compacted at ambient temperatures to form a pavement. The asphalt concrete formed of the asphalt mix achieves sufficient strength immediately after compaction at an ambient temperature.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: October 31, 2000
    Assignee: Hikarigiken Co., Ltd.
    Inventors: Terutaka Kitagawa, Chikao Yokokawa
  • Patent number: 5290324
    Abstract: The present invention provides a process for producing a coal-water mixture using a reaction mixture obtained by subjecting a low-rank coal of high water content to a hydrothermal treatment in the presence of carbon monoxide and water at a temperature not higher than the critical temperature of water. The above hydrothermal treatment makes the walls of pores present in the coal hydrophobic and densifies the coal matrix, whereby the coal after the treatment has a lower equilibrium moisture content. Hence, it becomes possible to produce a coal-water mixture containing a high concentration of coal and having good stability and fluidity, from a low-rank coal of high water content which has been unusable as a material for a coal-water mixture. Further, in the production of a coal-water mixture from the above reaction mixture, the amount of surfactant used can be reduced because the liquid phase of the reaction mixture contains a large amount of humic acid having surface activity.
    Type: Grant
    Filed: June 24, 1992
    Date of Patent: March 1, 1994
    Assignee: Mitsui Mining Company, Limited
    Inventors: Chikao Yokokawa, Sadao Wasaka