Patents by Inventor Kazuhiro Kawamata

Kazuhiro Kawamata 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: 5227429
    Abstract: A poly(arylene sulfide) resin composition comprised of 100 parts by weight of a resin mixture of (A) 50 to 98% by weight of a heat-treated poly(arylene sulfide) such as heat-treated polyphenylene sulfide and (B) 50 to 2% by weight of a styrene/butadiene/styrene block copolymer elastomer or a modified product thereof, and 0.2 to 10 parts by weight of an aromatic maleimide compound represented by the formula (1): ##STR1## wherein R.sub.1 is a phenylene-containing radical, or the formula (2): ##STR2## wherein R.sub.2 is alkylene and n is 0, 1 or 2. The resin composition has a good impact resistance, elongation and flexibility.
    Type: Grant
    Filed: November 21, 1991
    Date of Patent: July 13, 1993
    Assignee: Tohpren Co., Ltd.
    Inventors: Takashi Kawamura, Yukio Imai, Kazuhiro Kawamata, Takayuki Okada, Junichiro Furuta
  • Patent number: 5071949
    Abstract: Disclosed is a process for the preparation of polyphenylene-sulfide resins, wherein an aromatic polyhalide compound is reacted with an alkali metal sulfide, or hydrogen sulfide and an alkali metal base, or an alkali metal hydrosulfide and an alkali metal base in the presence of an amide polar solvent. A polyphenylene-sulfide resin having a cyclic oligomer content lower than 1.5% by weight, as determined according to the methylene chloride extraction method, is obtained by (a) carrying out the reaction in the absence a polymerization assistant, (b) using the amide polar solvent in an amount not larger than 400 g per mole of the aromatic polyhalide compound, and (c) subjecting the polymerization liquid obtained by the reaction to hot solid-liquid separation at a temperature at least 50.degree. C. but lower than the boiling point of the solvent used, and washing the separated solid with the solvent used for the reaction, which is heated at a temperature at least 50.degree. C.
    Type: Grant
    Filed: October 16, 1989
    Date of Patent: December 10, 1991
    Assignee: Tohpren Co., Ltd.
    Inventors: Yoshiaki Nakamura, Kazuyoshi Nagaki, Yuichiro Shiro, Kazuhiro Kawamata