Patents by Inventor Ritsuro Tada

Ritsuro Tada 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: 4784917
    Abstract: A thermosetting resin composition comprising as essential constituents (a) a prepolymer comprising a poly(p-hydroxystyrene) derivative represented by the general formula ##STR1## wherein A represents a hydrogen or halogen atom or an alkenyl or alkenoyl group having 2 to 4 carbon atoms, m represents a number in the range of from 1 to 4, and n represents a number in the range of from 1 to 100, and (b) a 1,2-polybutadiene or a derivative thereof. By using this novel resin composition and a customary equipment and procedure, it is easy to obtain a tack-free prepreg which is able to produce laminated materials of low permittivity suitable for use in multilayer printed circuit boards improved in peel strength of bonded copper foil, mechanical strengths, flame retardancy, and heat resistance, as compared to conventional printed circuit boards.
    Type: Grant
    Filed: April 22, 1986
    Date of Patent: November 15, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Keiko Tawara, Akira Nagai, Akio Takahashi, Katuo Sugawara, Masahiro Ono, Ritsuro Tada, Motoyo Wajima, Toshikazu Narahara
  • Patent number: 4738900
    Abstract: Cured resin obtained by polymerization by heating of a thermo-setting, polymerizable composition comprising at least two kinds of polymerizable compounds whose exothermic polymerization temperature ranges at polymerization by heating substantially coincide with each other, for example, an aromatic maleimide compound and an aromatic cyanamide compound, the composition showing a substantially one exothermic polymerization peak at the polymerization by heating, has a good heat resistance, and a laminated, high density wiring board with a good heat resistance, capable of being directly loaded with LSI chips and chip carriers can be obtained, using the composition.
    Type: Grant
    Filed: April 23, 1986
    Date of Patent: April 19, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Ono, Akio Takahashi, Katuo Sugawara, Ritsuro Tada, Akira Nagai, Motoyo Wajima, Toshikazu Narahara
  • Patent number: 4607094
    Abstract: The thermosetting resin composition of the present invention is prepared by mixing an aromatic cyanamide compound with a cyclic ester compound and/or a cyclic amide compound. Although a solventless type composition is preferable, the present invention is not limited thereto. The cured product of the present invention can be prepared by heating and curing said thermosetting resin composition. The obtained cured product of the present invention usually contains melamine rings, isomelamine rings and linear polyester and/or a linear polyamide units.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: August 19, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Katuo Sugawara, Akio Takahashi, Masahiro Ono, Ritsuro Tada, Motoyo Wajima, Toshikazu Narahara, Akira Nagai
  • Patent number: 4587162
    Abstract: A resin composition comprising a prepolymer of homopolymer or copolymer of isocyanuric acid derivative or cyanuric acid derivative, and a cyclized polybutadiene can give a laminate for multi-layer printed circuit boards excellent in heat resistance, dimensional stability and high-frequency electrical properties.
    Type: Grant
    Filed: July 12, 1985
    Date of Patent: May 6, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Akira Nagai, Akio Takahashi, Katuo Sugawara, Masahiro Ono, Ritsuro Tada, Motoyo Wajima, Toshikazu Narahara
  • Patent number: 4486583
    Abstract: A polymer which has excellent heat resistance and mechanical properties which is useful as a molding material, contains the structural units having the following formulae [I] and [II]: ##STR1## wherein A and B each represents an at least divalent organic group having at least one aromatic ring such as a diphenyl ring; and m and n each represents a number of at least 1. The polymer is used in the form of a solution or varnish as an impregnating, laminating, bonding or film-forming coating or prepreg-forming varnish. A resin composition for forming the polymer contains an aromatic cyanamide compound and an aromatic amine which are reacted to form a prepolymer which, upon heating, is converted into a cured polymer having the structural units of formulae [I] and [II].
    Type: Grant
    Filed: August 23, 1983
    Date of Patent: December 4, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Akio Takahashi, Masahiro Ono, Ritsuro Tada, Motoyo Wajima, Hirosada Morishita
  • Patent number: 4393188
    Abstract: A process for preparing a thermosetting maleimide type prepolymer which comprises reacting (A) a polyfunctional maleimide compound, (B) a bis-maleimide, (C) a diamine and (D) an epoxy compound. The maleimide type prepolymer prepared according to the process of the present invention has rapid curability and excellent solubility in low boiling point solvents such as acetone, methyl ethyl ketone and methyl cellosolve, which are available at low cost. Accordingly, the prepolymer is advantageously used especially for the production of laminated boards having good heat resisting properties, low moisture absorption and good adhesion to various substrates such as a copper foil.
    Type: Grant
    Filed: February 12, 1981
    Date of Patent: July 12, 1983
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Akio Takahashi, Motoyo Wajima, Ritsuro Tada, Hirosada Morishita, Yutaka Mizuno, Shunya Yokozawa, Kenji Tsukanishi
  • Patent number: 3984373
    Abstract: An epoxy resin composition containing an N,N'-unsaturated amic acid compound represented by the general formula, HOCO--R.sub.2 --CONH--R.sub.1 --Y, wherein R.sub.1 is a divalent group having 2 or more carbon atoms, R.sub.2 is a divalent group having a carbon-to-carbon double bond, and Y is ##EQU1## or --NHCO--R.sub.2 --COOH. The composition is characterized, by being favorable in curing characteristics, heat resistance, and flame retardance.
    Type: Grant
    Filed: March 27, 1974
    Date of Patent: October 5, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Akio Takahashi, Motoyo Wajima, Ritsuro Tada
  • Patent number: 3963796
    Abstract: An epoxy resin composition having a remarkably improved storage stability and an excellent hardening characteristic when heated, which comprises an epoxy resin and an aromatic amino carboxylic acid or a derivative thereof as a hardener for the epoxy resin. This composition can be molded by injection molding, heretofore being deemed inapplicable to epoxy resin compositions, whereby the molded articled of epoxy resin can be produced with a high molding efficiency.
    Type: Grant
    Filed: January 6, 1971
    Date of Patent: June 15, 1976
    Assignees: Hitachi, Ltd., Hitachi Chemical Company, Ltd.
    Inventors: Hitoshi Yokono, Akio Nishikawa, Ritsuro Tada, Yasuo Miyadera