Patents by Inventor Hazime Niwa

Hazime Niwa 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).

  • Concrete joint sealant plate and process for manufacturing thereof
    Patent number: 4464424
    Abstract: A method for preparing a concrete joint sealant plate, comprising the steps of impregnating asphalt emulsion into fibrous plate under a reduced pressure and then drying it by means of a heating presser; and a concrete joint sealant plate produced therefrom.
    Type: Grant
    Filed: December 22, 1981
    Date of Patent: August 7, 1984
    Assignee: Aoi Chemical, Inc.
    Inventors: Hazime Niwa, Saburo Furukawa