Patents by Inventor Choji Tomizawa

Choji Tomizawa 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: 6008287
    Abstract: An adhesive composition obtainable by blending a component (C) to components (A) and (B), wherein the weight ratio of (A)/(B) is from 95/5 to 40/60, and the amount of the component (C) is from 5 to 50 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B):(A): a condensate of resorcinol and formaldehyde or a condensate of resorcinol, phenol and formaldehyde,(B): an aqueous emulsion containing an ethylene-vinyl acetate-based copolymer and the weight ratio of ethylene/vinyl acetate is from 3/97 to 40/60,(C): a formaldehyde-based hardening agent or a hexamethylenetetramine-based hardening agent.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: December 28, 1999
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Yutaka Shibata, Choji Tomizawa
  • Patent number: 4279950
    Abstract: A jointing of concrete structure comprising applying an adhesive to a base concrete structure and applying a new concrete thereto, which is characteristic in that the adhesive comprises a vinyl acetate-ethylene copolymer emulsion having a glass transition temperature of -5.degree. to +5.degree. C., said adhesive being the vinyl acetate-ethylene copolymer emulsion per se, or a cement paste or cement mortar which contains the vinyl acetate-ethylene copolymer emulsion. The jointing of the present invention can give a strong joint force between the old concrete structure and the new concrete.
    Type: Grant
    Filed: December 21, 1979
    Date of Patent: July 21, 1981
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Hiromichi Tanaka, Choji Tomizawa
  • Patent number: 4128518
    Abstract: A pressure-sensitive adhesive containing a base material therefore comprising an aqueous emulsion of vinyl acetate-ethylene copolymer having an ethylene content of 15 to 40% by weight, preferably 20 to 35% by weight, the benzene-insoluble part of less than 30% by weight, preferably less than 20% by weight, and an intrinsic viscosity of the benzene-soluble part of 0.4 to 1.4 dl/g, preferably 0.6 to 1.0 dl/g, (at 30.degree. C) which is prepared by the emulsion copolymerization of vinyl acetate and ethylene and optionally at least one unsaturated monovinyl monomer in the presence of a protective colloid and a polyoxyethylenic nonionic sulfactant, or a base material comprising a blend of said aqueous emulsion of vinyl acetate-ethylene copolymer as set forth above and an emulsion of an acrylic ester copolymer; and the aqueous emulsion of vinyl acetate-ethylene copolymer useful as the base material for the pressure-sensitive adhesive.
    Type: Grant
    Filed: April 20, 1977
    Date of Patent: December 5, 1978
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takeo Oyamada, Choji Tomizawa, Masahiro Domoto, Shizuo Narisawa
  • Patent number: 4123405
    Abstract: In the process for producing the aqueous emulsion of vinyl chloride/vinyl acetate/ethylene terpolymer by polymerizing vinyl chloride, vinyl acetate and ethylene in an aqueous dispersion system under ethylene pressure in the presence of an emulsifier and/or protective colloid using a radical initiator, the improvement which comprises adding vinyl chloride and vinyl acetate to said aqueous dispersion system at substantially fixed rates while maintaining a required amount of unreacted vinyl acetate in the system, and, after completion of addition of vinyl chloride, adding additional vinyl acetate of 3 to 20% by weight based on the total amount of vinyl acetate which has been added until that time and continuing the polymerization until the concentration of vinyl acetate in the system is decreased to 1% by weight or less, wherein the volume of the aqueous dispersion system is at least 50% by volume based on the volume of the reactor when addition of the additional vinyl acetate is completed.
    Type: Grant
    Filed: June 9, 1977
    Date of Patent: October 31, 1978
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takeo Oyamada, Kazuhisa Satoh, Choji Tomizawa, Takamasa Ishihara
  • Patent number: 4108819
    Abstract: A process for producing an aqueous dispersion of vinyl acetate-ethylene copolymer containing an epoxide resin, which comprises emulsion-copolymerizing vinyl acetate, wherein an epoxide resin is dissolved, and ethylene at a pH value of 3 to 7 so that the ratio of vinyl acetate to ethylene is 60-95 : 40-5 by weight and the content of the epoxide resin is 0.5 to 60% by weight on the basis of the total weight of the solid resin components. The aqueous dispersion is useful as a two-pack type adhesive or coating composition in combination with a curing agent.
    Type: Grant
    Filed: April 22, 1977
    Date of Patent: August 22, 1978
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takeo Oyamada, Shinobu Tsuru, Choji Tomizawa, Yoshito Taira