Patents by Inventor Masazumi Nakashima

Masazumi Nakashima 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).

  • BN-group ceramics having excellent resistance to loss by dissolving
    Patent number: 5389587
    Abstract: h-BN-group ceramics having excellent dissolving-loss proofness against hot melt of metal, glass and the like. If 50% or more of h-BN and 1-less than 50% of complex compound consisting of two or more kinds of compounds selected from the group of (AlN, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3 and SiO.sub.2) are contained in a sintered body, then dissolving-loss proofness against hot melt is remarkably improved. Furthermore, besides the aforementioned complex compound, if less than 30% of one kind or two or more kinds compounds selected from the group (AlN, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3 and SiO.sub.2) is contained, then in addition to the dissolving-loss proofness, unwettability and thermal shock proofness are extremely improved.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: February 14, 1995
    Assignee: Kabushiki Kaisha Kouransha
    Inventors: Masazumi Nakashima, Sumihiko Kurita
  • Boron nitride sinter and process for its production
    Patent number: 5334339
    Abstract: The present invention relates to a high-strength BN single sinter or a high-strength composite sinter consisting of BN and other ceramics, and a process for its production. The present invention is characterized in that an amorphous BN powder or a powder capable of producing armorphous BN in the course of the sintering step is used as a part or whole of a starting material for a BN component. A boron nitride sinter obtained according to the present invention can be effectively utilized, for instance, as an electronic component part.
    Type: Grant
    Filed: May 19, 1988
    Date of Patent: August 2, 1994
    Assignee: Kabushiki Kaisha Kouransha
    Inventors: Masazumi Nakashima, Hiroshi Nakawara, Suminiko Kurita
  • Boron nitride ceramics and molten metal container provided with members made of the same ceramics
    Patent number: 5308044
    Abstract: The present invention relates to ceramics having excellent fusing damage resistivity against melt of metal or other inorganic materials. If a member formed of BN ceramics in the prior art comes into contact with melt of metal, glass or the like, the member would be readily fused and damaged at its contact portion. Hence, if AlN in the range of 1.ltoreq.AlN<50 weight % is added to BN ceramics containing 50 weight % or more of BN component, the fusing damage resistivity is greatly improved. Furthermore, Y.sub.2 O.sub.3 whose weight proportion relative to AlN content is 1.0-10.0%, is added, strength of the BN ceramics is greatly improved. A protective cap for a thermocouple formed of the ceramics according to the present invention is excellent in durability against molten metal, and so, continuous temperature measurement for molten metal is possible.
    Type: Grant
    Filed: August 14, 1991
    Date of Patent: May 3, 1994
    Assignee: Kabushiki Kaisha Kouransha
    Inventors: Masazumi Nakashima, Mitsunori Kusumoto, Sumihiko Kurita, Hiroshi Nakamura, Katsumi Ura, Akira Murata