Patents by Inventor Satoru Ashitaka

Satoru Ashitaka 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: 10577393
    Abstract: A porous hollow fiber membrane is provided for the treatment of a protein-containing liquid, which can effectively separate and remove a substance such as a small diameter virus, and which can allow effective permeation of a useful substance to be recovered such as protein in high concentration. The porous hollow fiber membrane has an asymmetric structure having a dense layer in an outer layer only and contains a hydrophobic polymer and a first hydrophilic polymer, the surface and the porous part of the hollow fiber membrane are coated with a second hydrophilic polymer, the hydrophobic polymer is a polysulfone-type polymer, the first hydrophilic polymer is a copolymer of vinylpyrrolidone with vinyl acetate, and the second hydrophilic polymer is a polysaccharide or a polysaccharide derivative. The porous hollow fiber membrane is obtained by co-dissolving the hydrophobic polymer and the first hydrophilic polymer and then the second hydrophilic polymer is coated.
    Type: Grant
    Filed: October 23, 2013
    Date of Patent: March 3, 2020
    Assignee: TOYOBO CO., LTD.
    Inventors: Satoru Ashitaka, Toru Uenishi, Noriko Monden, Noriaki Kato
  • Patent number: 9492794
    Abstract: An object of the present invention is to provide a porous hollow fiber membrane for the treatment of a protein-containing liquid where the substances to be removed such as small-sized virus contained in a solution can be efficiently separated and removed and, at the same time, useful substances to be recovered such as protein can be efficiently permeated and the decrease in the permeation characteristics thereof with elapse of time is small. The porous hollow fiber membrane for the treatment of a protein-containing liquid of the present invention is characterized in that the membrane comprises a hydrophobic polymer and a hydrophilic polymer, its permeability for pure water is 10 to 300 L/(h·m2·bar) and, when a 0.5% immunoglobulin solution is subjected to filtration at a constant pressure of 1.0 bar for 60 minutes in dead-end filtration mode, its filtration time and accumulated amount of recovered filtrate are substantially in a linear relation.
    Type: Grant
    Filed: March 8, 2011
    Date of Patent: November 15, 2016
    Assignee: TOYOBO BOSEKI KABUSHIKI KAISHA
    Inventors: Hideyuki Yokota, Toru Uenishi, Hirofumi Ogawa, Satoru Ashitaka, Noriko Monden
  • Publication number: 20150232506
    Abstract: A porous hollow fiber membrane is provided for the treatment of a protein-containing liquid, which can effectively separate and remove a substance such as a small diameter virus, and which can allow effective permeation of a useful substance to be recovered such as protein in high concentration. The porous hollow fiber membrane has an asymmetric structure having a dense layer in an outer layer only and contains a hydrophobic polymer and a first hydrophilic polymer, the surface and the porous part of the hollow fiber membrane are coated with a second hydrophilic polymer, the hydrophobic polymer is a polysulfone-type polymer, the first hydrophilic polymer is a copolymer of vinylpyrrolidone with vinyl acetate, and the second hydrophilic polymer is a polysaccharide or a polysaccharide derivative. The porous hollow fiber membrane is obtained by co-dissolving the hydrophobic polymer and the first hydrophilic polymer and then the second hydrophilic polymer is coated.
    Type: Application
    Filed: October 23, 2013
    Publication date: August 20, 2015
    Applicant: TOYOBO CO., LTD.
    Inventors: Satoru Ashitaka, Toru Uenishi, Noriko Monden, Noriaki Kato
  • Publication number: 20120305472
    Abstract: An object of the present invention is to provide a porous hollow fiber membrane for the treatment of a protein-containing liquid where the substances to be removed such as small-sized virus contained in a solution can be efficiently separated and removed and, at the same time, useful substances to be recovered such as protein can be efficiently permeated and the decrease in the permeation characteristics thereof with elapse of time is small. The porous hollow fiber membrane for the treatment of a protein-containing liquid of the present invention is characterized in that the membrane comprises a hydrophobic polymer and a hydrophilic polymer, its permeability for pure water is 10 to 300 L/(h·m2·bar) and, when a 0.5% immunoglobulin solution is subjected to filtration at a constant pressure of 1.0 bar for 60 minutes in dead-end filtration mode, its filtration time and accumulated amount of recovered filtrate are substantially in a linear relation.
    Type: Application
    Filed: March 8, 2011
    Publication date: December 6, 2012
    Applicant: TOYO BOSEKI KABUSHIKI KAISHA
    Inventors: Hideyuki Yokota, Toru Uenishi, Hirofumi Ogawa, Satoru Ashitaka, Noriko Monden