Patents by Inventor Sei Ishizawa

Sei Ishizawa 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: 6001752
    Abstract: Melt-adhesive composite fibers; non-woven fabrics from the composite fibers fused at intersectional points of the fibers; and surface materials for medical supplies such as sanitary napkins and paper diapers are disclosed. The composite fibers have a polypropylene as the first component and a polymer mainly composed of a polyethylene as the second component which is continuously present on at least a part of the fiber surface in the lengthwise direction of the fiber; have three-dimensional crimps of 4 to 16/inch; have a filamentary denier of 1.0 to 2.0, and have an apparent cut length of 20 to 40 mm. The composite fibers can be produced by extruding a polypropylene and a polymer mainly comprising a polyethylene through a spinneret for composite spinning to form unstretched composite filaments having such structure as mentioned above, stretching the unstretched composite filaments at a temperature of higher than 90.degree. C., but lower than 130.degree. C. at a stretching ratio of 0.60 to 0.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: December 14, 1999
    Assignee: Chisso Corporation
    Inventors: Sei Ishizawa, Masayasu Suzuki, Hirokazu Terada
  • Patent number: 5780155
    Abstract: Melt-adhesive composite fibers; non-woven fabrics from the composite fibers fused at intersectional points of the fibers; and surface materials for medical supplies such as sanitary napkins and paper diapers are disclosed. The composite fibers have a polypropylene as the first component and a polymer mainly composed of a polyethylene as the second component which is continuously present on at least a part of the fiber surface in the lengthwise direction of the fiber; have three-dimensional crimps of 4 to 16/inch; have a filamentary denier of 1.0 to 2.0, and have an apparent cut length of 20 to 40 mm. The composite fibers can be produced by extruding a polypropylene and a polymer mainly comprising a polyethylene through a spinneret for composite spinning to form unstretched composite filaments having such structure as mentioned above, stretching the unstretched composite filaments at a temperature of higher than 90.degree. C., but lower than 130.degree. C. at a stretching ratio of 0.60 to 0.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: July 14, 1998
    Assignee: Chisso Corporation
    Inventors: Sei Ishizawa, Masayasu Suzuki, Hirokazu Terada