Patents by Inventor Kazuo Kusida

Kazuo Kusida 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).

  • Process for the preparation of cross-linked polyarylene sulfide
    Patent number: 5268451
    Abstract: The present invention discloses a process for producing a granular polyarylene sulfide which has a high melt viscosity and a high degree of cross-linkage, becomes gel under melting and is easy to handle in the production and the fabrication thereof.The process disclosed herein comprises (1) a step (A) an initial-stage polymerization step for obtaining a polyarylene sulfide by reacting an alkali metal sulfide, a dihaloaromatic compound and a polyhaloaromatic compound, having three or more halogen substituents in a molecule, in the presence of water in an amount of 0.5 to 2.9 moles per mol of said alkali metal sulfide at a temperature in the range of 180.degree. to 235.degree. C. until the total conversion ratio of said dihalo- and polyhaloaromatic compounds reaches 50 to 98% and the melt viscosity of a polyarylene sulfide obtained at the end of the step becomes 5 to 5,000 poise, measured at 310.degree. C.
    Type: Grant
    Filed: December 3, 1992
    Date of Patent: December 7, 1993
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yo Iizuka, Toshio Hosokawa, Yoshinobu Itoh, Shinji Yamamoto, Kazuo Kusida, Takayuki Katto
  • Process for the preparation of cross-linked polyarylene sulfide
    Patent number: 5200500
    Abstract: The present invention discloses a process for producing a granular polyarylene sulfide which has a high melt viscosity and a high degree of cross-linkage, becomes gel under melting and is easy to handle in the production and the fabrication thereof.The process disclosed herein comprises (1) a step (A) an initial-stage polymerization step for obtaining a polyarylene sulfide by reacting an alkali metal sulfide, a dihaloaromatic compound and a polyhaloaromatic compound, having three or more halogen substituents in a molecule, in the presence of water in an amount of 0.5 to 2.9 moles per mol of said alkali metal sulfide at a temperature in the range of 180.degree. to 235.degree. C. until the total conversion ratio of said dihalo- and polyhaloaromatic compounds reaches 50 to 98% and the melt viscosity of a polyarylene sulfide obtained at the end of the step becomes 5 to 5,000 poise, measured at 310.degree. C.
    Type: Grant
    Filed: August 22, 1990
    Date of Patent: April 6, 1993
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Yo Iizuka, Toshio Hosokawa, Yoshinobu Itoh, Shinji Yamamoto, Kazuo Kusida, Takayuki Katto
  • Densification of particulate porous fluorinated resins
    Patent number: 4069291
    Abstract: A suspension of a particulate porous fluorinated resin in an aqueous medium containing a powder of an inorganic suspension stabilizer is heated approximately at a melting temperature of the resin whereby the resin is densified, the degree of densification of the resin depending on the heating temperature.
    Type: Grant
    Filed: June 18, 1976
    Date of Patent: January 17, 1978
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Kunizoh Kidoh, Hideki Wakamori, Genzo Asai, Kazuo Kusida
  • Process for producing vinylchloride resin having a highly porous uniform granular structure
    Patent number: 3966696
    Abstract: A process for suspension polymerization of vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith in an aqueous medium in the presence of an oil-soluble polymerization catalyst is improved by the use of a suspending agent comprising a well known protective colloid and a saccharose alkyl ester.
    Type: Grant
    Filed: March 6, 1975
    Date of Patent: June 29, 1976
    Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Kunizoh Kidoh, Hidetora Kashio, Toshio Hosokawa, Kazuo Kusida