Patents by Inventor Shuji Nakatsuka

Shuji Nakatsuka 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).

  • Publication number: 20210346849
    Abstract: A hollow fiber porous membrane includes polyethersulfone or polysulfone. The hollow fiber porous membrane has an inner diameter from 300 to 600 ?m, a thickness from 70 to 200 ?m, a molecular weight cut-off of 10000 or lower, and a plurality of pores having a pore diameter from 0.1 to 0.5 ?m throughout an outer surface; and a swelling rate of less than 5% as defined below: Swelling Rate (%): for 20 or more of the hollow fiber porous membranes, after a membrane thickness in a cross section of each one of the hollow fiber porous membranes in the width direction is measured at randomly selected 10 or more locations, an average membrane thickness is calculated based on 200 or more locations in total, and the swelling rate is calculated by a formula below: Swelling Rate (%)=(location numbers where the membrane thickness as measured exceeded 1.3 times the average membrane thickness)/(membrane thickness measurement numbers)×100.
    Type: Application
    Filed: September 18, 2019
    Publication date: November 11, 2021
    Applicants: DAICEN MEMBRANE-SYSTEMS Ltd., NIPRO CORPORATION
    Inventors: Shuji NAKATSUKA, Takashi SUNOHARA, Toshinari TAKAHASHI
  • Patent number: 6788368
    Abstract: The reflective liquid crystal display device comprises a polarizing plate disposed forwardly of a liquid crystal cell, a relector which is disposed on backside of the liquid crystal cell and reflects an incident light, and a light-scattering sheet which is disposed forwardly of the reflector and scatters the incident light isotopically. The light-scattering sheet can be prepared with the use of a spinodal decomposition method of coating a mixture liquid containing a plurality of polymers varying in refractive index on a transparent support and evaporating or removing a solvent to form a light-scattering layer having a droplet phase structure. The light-scattering layer includes a light-scattering layer showing a maximum intensity of the scattered-light at scattering angles of 3 to 40°, and a light-scattering layer showing maximums intensity of the scattered-light respectively at smaller angles of 2 to 2° and larger angle &thgr;b.
    Type: Grant
    Filed: November 23, 2001
    Date of Patent: September 7, 2004
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Hiroshi Takahashi, Yoshiyuki Nishida, Masaya Omura, Shuji Nakatsuka
  • Patent number: 6632366
    Abstract: The present invention relates to a cellulose compound hollow fiber membrane having high mechanical strength and is hardly degraded by microorganisms, wherein a cellulose compound is comprised as a membrane material, the thickness of the membrane is 50 to 500 &mgr;m, a dense membrane surface having an average pore diameter of 0.001 to 0.05 &mgr;m exists on the internal and/or external surface thereof, the inside of the membrane is composed of a three-dimensional network-like porous structure having voids with an average pore diameter of 0.05 to 2 &mgr;m, and 70% by weight or more of the membrane material is cellulose acetate propionate or cellulose acetate butyrate.
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: October 14, 2003
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Shuji Nakatsuka, Sachiko Matsuoka
  • Publication number: 20030025856
    Abstract: The reflective liquid crystal display device comprises a polarizing plate 1 disposed forwardly of the liquid crystal cell 6, a reflecting means 5 which is disposed on backside of the liquid crystal cell and reflects an incident light, and a light-scattering sheet 2 which is disposed forwardly of reflecting means and scatters the incident light isotopically. The light-scattering sheet can be prepared with the use of spinodal decomposition method comprising by coating a mixture liquid containing a plurality of polymers varying in refractive index on a transparent support and evaporating or removing a solvent to form a light-scattering layer having a droplet phase structure. The light-scattering layer includes a light-scattering layer showing a maximum intensity of the scattered-light at scattering angle of 3 to 40°, and a light-scattering layer showing maximums intensity of the scattered-light respectively at smaller angle of 2 to 20° and larger angle &thgr;b.
    Type: Application
    Filed: November 23, 2001
    Publication date: February 6, 2003
    Inventors: Hiroshi Takahashi, Yoshiyuki Nishida, Masaya Omura, Shuji Nakatsuka
  • Patent number: 6372136
    Abstract: To provide a cellulose acetate semipermeable membrane having a high filtration rate and high mechanical strength and which is hardly degraded by microorganisms, the present invention provides a cellulose acetate semipermeable membrane containing a cellulose acetate having an &agr;-cellulose content of not less than 99% by weight, a 6 wt/vol % viscosity of 20 to 220 mPa·s at 25±1° C. and an acetylation degree of 58 to 62%. The cellulose acetate semipermeable membrane is suitable particularly as a hollow fiber membrane.
    Type: Grant
    Filed: April 5, 2000
    Date of Patent: April 16, 2002
    Assignee: Daicel Chemical Industries, Ltd.
    Inventor: Shuji Nakatsuka
  • Patent number: 6177181
    Abstract: Porous membranes having a micro phase separation structure and showing a light transmittance at the wavelength of 400 nm of not less than 30% are obtained by the dry phase conversion method comprising drying a coating layer of a dope containing a polymer, a good solvent for the polymer and a poor solvent for the polymer which solvent has a higher boiling point than the good solvent. The polymer includes cellulose derivatives, vinyl-series polymers such as acrylonitrile-series polymers and (meth)acrylic acid ester-series polymers, polysulfone-series polymers, and the like. The porous polymer membranes have a porosity of 10 to 60%, a mean pore size of about 0.002 to 0.35 &mgr;m and a maximum pore size of not greater than 0.4 &mgr;m. These porous membranes shows not only excellent transparency but also high productivity.
    Type: Grant
    Filed: July 23, 1998
    Date of Patent: January 23, 2001
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Toyozo Hamada, Shuji Nakatsuka, Kiyoharu Mizumoto