Patents by Inventor Seiichi Igarashi

Seiichi Igarashi 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).

  • Method for preparing paper board having improved wet compression strength
    Patent number: 4091167
    Abstract: This invention relates to a method for preparing paper board having excellent wet tensile strength and compression strength, which comprises (a) having paper board impregnated or coated with a mixture of an unsaturated vinyl ester prepolymer having a molecular weight of 300 to 3000 and having at least one hydroxyl group at the .beta.-position with respect to an ester bond in the molecule with at least one monomer selected from the group of methylacrylate, ethylacrylate and butylacrylate in a mixing weight ratio of 10:90-40:60, and (b) irradiating the paper board having the resinous mixture with electrons to cure the resinous mixture.
    Type: Grant
    Filed: May 12, 1976
    Date of Patent: May 23, 1978
    Assignee: Rengo Co., Ltd.
    Inventors: Toshio Okada, Hideharu Ohtsuki, Hiroshi Inagaki, Toshiaki Hanyuda, Masateru Tokuno, Seiichi Igarashi
  • Paperboard impregnated with polyurethane resin
    Patent number: 3953169
    Abstract: A paperboard impregnated with polyurethane resin having specific NCO content and average molecular weight at the rate of 0.05 to 5.0 weight percent relative to the paperboard has excellent mechanical properties such as compressive strength, tensile strength, tearing strength, folding endurance, etc., even in wet state.
    Type: Grant
    Filed: September 5, 1974
    Date of Patent: April 27, 1976
    Assignee: Takeda Chemical Ind., Ltd.
    Inventors: Seiichi Igarashi, Kin-ichi Shirakawa, Kazuo Kimura, Akira Ogino