Patents by Inventor Seikoh Naganuma

Seikoh Naganuma 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: 5106563
    Abstract: A pre-oriented molded article of ultrahigh-molecular-weight polyethylene is composed of ultrahigh-molecular-weight polyethylene having an intrinsic viscosity of at least 5 dl/g, has a degree of orientation of at least 0.8, and has such a creep property that a stretched product of the molded article having a degree of orientation of about 0.97 shows an elongation of not more than 2% in an atmosphere at 80.degree. C. at 1000 seconds. The pre-oriented molded article is produced by (1) extruding a high-concentration molding solution composed of 15 to 80 parts by weight of ultrahigh-molecular-weight polyethylene and 85 to 20 parts by weight of a solvent capable of dissolving said polyethylene from a molding die at a temperature at which the molding solution remains a solution, (2) taking up the extrudate at a draft ratio of at least 3, and cooling the extrudate during or after take-up to crystallize the polyethylene in the extrudate and to form a pre-oriented molded article.
    Type: Grant
    Filed: September 13, 1989
    Date of Patent: April 21, 1992
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Kazuo Yagi, Seikoh Naganuma
  • Patent number: 4429079
    Abstract: This invention relates to a composition comprising a mixture of at least two ethylene-rich ethylene/alpha-olefin copolymers (A) and (B) below which has excellent transparency and impact strength and improved properties, particularly low-temperature heat sealability, heat seal strength and flexural resistance.(A) 95 to 40% by weight of a random copolymer of ethylene and an alpha-olefin having 5 to 10 carbon atoms which has a melt index of 0.1 to 20 g/10 min., a density of 0.910 to 0.940 g/cm.sup.3, a crystallinity by X-rays of 40 to 70%, a melting point of 115.degree. to 130.degree. C. and an ethylene content of 94 to 99.5 mole %; and(B) 5 to 60% by weight of a random copolymer of ethylene and an alpha-olefin having 3 to 10 carbon atoms which has a melt index of 0.1 to 50 g/10 min., a density of 0.870 to 0.900 g/cm.sup.3, a crystallinity by X-rays of 5 to 40%, a melting point of 40.degree. to 100.degree. C. and an ethylene content of 85 to 95 mole %.
    Type: Grant
    Filed: March 11, 1982
    Date of Patent: January 31, 1984
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Yuzo Shibata, Seikoh Naganuma