Patents by Inventor Takumi Ishiwaka

Takumi Ishiwaka 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: 5137931
    Abstract: Disclosed is a foamable phenolic resin composition comprising, as indispensable components, 100 parts by weight as solids of a resol type phenolic resin, 3 to 100 parts by weight of an acidic curing agent, 1 to 50 parts by weight of a blowing agent, 0.1 to 50 parts by weight of a saccharide and 0.1 to 10 parts by weight of a foam stabilizer, in which a partial or complete acetylation product of a castor oil/ethylene oxide adduct having a hydroxyl value smaller than 15 mg-KOH/g, which is obtained by acetylating a castor oil/ethylene oxide adduct formed by adding 20 to 70 moles of ethylene oxide to 1 mole of castor oil is used as the foam stabilizer and/or a resol type liquid penolic resin obtained by subjecting a phenol and an aldehyde to addition condensation reaction in the presence of a catalyst having a metal ion-forming capacity, in which the residual amount of the catalyst is smaller than 0.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: August 11, 1992
    Assignees: Asahi Yukizai Kogyo Co., Ltd., Bridgestone Corporation
    Inventors: Syuji Okumura, Shigetoshi Awano, Masahiro Kinoshita, Kazuo Tamemoto, Akihiro Maruyama, Takumi Ishiwaka, Takashi Ohashi
  • Patent number: 5093378
    Abstract: An improved process for producing a flexible polyurethane foam having improved flame retardance and physical properties by reacting a polyhydroxy compound and a polyisocyanate compound in the presence of a blowing agent, wherein the improvement comprises using as the polyhydroxy compound one in which an aldehyde condensation polymer has been formed by polycondensation and dispersed such that it accounts for preferably from 5 to 30 wt % of the total amount of the polyhydroxy compound, and adding as the flame retardant a melamine powder preferably in an amount of from 5 to 100 parts by weight for 100 parts by weight of said polyhydroxy compound.
    Type: Grant
    Filed: June 22, 1989
    Date of Patent: March 3, 1992
    Assignee: Bridgestone Corporation
    Inventors: Takumi Ishiwaka, Hajime Hasegawa, Takashi Ohashi
  • Patent number: 5008297
    Abstract: In a method for producing resol type phenol resin foams by using starting material for the foams prepared by blending a resol type phenol resin, a blowing agent and a catalyst, a low molecular weight resol type phenol resin with the number average molecular weight of less than 200 and a high molecular weight resol type phenol resin with the number average molecular weight of greater than 200 are mixed at a weight ratio of from 5/95 to 80/20 and used as the resol type phenol resin. The resol type phenol resin foams are excellent in adhesion, fire-proofness capable of foaming cure in a short time and useful for sprayed-in-place foaming, etc. The phenol resin foams produced by the invention are capable of integral foaming with rigid urethane resin foam layer into foamed laminates of excellent thermal insulation, fire-proofness, etc.
    Type: Grant
    Filed: May 25, 1989
    Date of Patent: April 16, 1991
    Assignee: Bridgestone Corporation
    Inventors: Akihiro Maruyama, Munehiko Kato, Takumi Ishiwaka, Katsuto Seki, Takashi Ohashi
  • Patent number: 4887923
    Abstract: There is provided a platen roll low in generation of noise with keeping superior printability which comprises a shaft and a single layer of rubber composition concentrically and tightly applied around said shaft or two layers of an inner layer of a resin concentrically and tightly applied around said shaft and an outer layer of a rubber composition concentrically and tightly applied around said inner layer.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: December 19, 1989
    Assignee: Bridgestone Corporation
    Inventors: Takumi Ishiwaka, Yukio Andoh, Michiyuki Yamaguchi, Shosuke Suzuki, Yoshinori Egashira, Takeo Yokobori, Takashi Ohashi
  • Patent number: 4707408
    Abstract: A roll for use in business machines has a shaft and a roll main body disposed at the circumference of said shaft, wherein the roll main body is made of a polyurethane resin comprising a surface layer composed of a skin layer and an inner layer composed of a foam layer which are formed into an integrated structure. The roll is suitably used for removing residual toners on the photo-sensitive drum in dry process copying machines.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: November 17, 1987
    Assignee: Bridgestone Corporation
    Inventors: Shigeru Iwasawa, Takumi Ishiwaka
  • Patent number: 4647596
    Abstract: Polyol component essentially consists of polyesterpolyetherpolyol containing polyesterpolyol by the weight ratio of 100:0 to 20:80, in which the polyesterpolyetherpolyol is a copolymer of polytetramethyleneglycol (PTMG) and .epsilon.-caprolactone by the weight ratio of 20:80 to 80:20 with an average molecular weight of 1000 to 3000 and the polyesterpolyol is a condensate of adipic acid as a main acid component with an average molecular weight of 1000 to 3000, is reacted with isocyanate component essentially consists of 4,4'-diphenylmethanediisocyanate (MDI) to make a prepolymer with terminal radical of NCO.
    Type: Grant
    Filed: April 28, 1986
    Date of Patent: March 3, 1987
    Assignee: Bridgestone Corporation
    Inventors: Seiji Ishii, Masanori Miyoshi, Takumi Ishiwaka, Osamu Kondo
  • Patent number: 4258139
    Abstract: A process for producing flame-resistant foam resins is disclosed. The flame-resistant foam resin is produced by reacting an organic polyisocyanate with urea.
    Type: Grant
    Filed: October 24, 1979
    Date of Patent: March 24, 1981
    Assignee: Bridgestone Tire Company Limited
    Inventors: Toshio Yukuta, Takumi Ishiwaka, Kiyoshi Usui
  • Patent number: 4234695
    Abstract: A method of producing polyurea foams is disclosed. The polyurea foam is produced by reacting an organic polyisocyanate with water in the presence of urea or by reacting a crude tolylene diisocyanate or a mixture of crude tolylene diisocyanate and crude diphenylmethane diisocyanate as an organic polyisocyanate with water in the presence of an amine catalyst, a silicone surfactant and, if necessary, a tin catalyst.
    Type: Grant
    Filed: October 25, 1979
    Date of Patent: November 18, 1980
    Assignee: Bridgestone Tire Co., Ltd.
    Inventors: Toshio Yukuta, Takumi Ishiwaka, Kiyoshi Usui
  • Patent number: 4221875
    Abstract: According to the present invention polyurethane foams, can be obtained as flame resistant and non-corrosive product. The invention specifies the foaming of raw material mixture comprising polyhydroxyl compound, polyisocyanate, blowing agent and etc. to be carried out in the presence of melamine powder added thereto as novel flame retardant, the final products being inexpensive and suitable to be used as structural material, etc.
    Type: Grant
    Filed: February 27, 1978
    Date of Patent: September 9, 1980
    Assignee: Bridgestone Tire Co., Ltd.
    Inventors: Toshio Yukuta, Takumi Ishiwaka, Noboru Yamaguchi