Patents by Inventor Masaaki Nishina

Masaaki Nishina 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: 5349049
    Abstract: A method of production of polyvinyl chloride resin for paste processing comprises recovering in 98% or more the polyvinyl chloride resin from an aqueous dispersion of the polyvinyl chloride resin for paste processing as aggregates by adding an organic fluid which is at most barely soluble in water and does not dissolve or swell the polyvinyl chloride resin to the aqueous dispersion in the presence of an aggregating agent, followed by separating the aggregated polyvinyl chloride resin particles from the aqueous phase of the aqueous dispersion. By the addition of the aggregating agent, dispersion of the resin particles into a medium is improved, fluidity of a sol thereof and the physical properties of molded articles formed therefrom are improved and blocking during the drying process is prevented.
    Type: Grant
    Filed: March 31, 1993
    Date of Patent: September 20, 1994
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Masaaki Nishina, Osamu Ozaki
  • Patent number: 4803260
    Abstract: A recovery method of vinyl chloride resin which comprises formulating an aggregate of vinyl chloride resin by adding to an aqueous dispersion of vinyl chloride resin an organic liquid which is difficultly soluble in water and does not dissolve or swell vinyl chloride resin and mixing the two; dehydrating the aggregate; and drying the same to recover granular vinyl chloride resin, the characteristic feature residing in that said aqueous dispersion is the one which has passed through the screen of 20 to 150-micron meshes.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: February 7, 1989
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Masaaki Nishina, Junsei Kawahuti
  • Patent number: 4721773
    Abstract: A granular vinyl chloride polymer is produced by mixing an aqueous dispersion of a vinyl chloride polymer with an organic liquid being difficulty soluble in water and incapable of dissolving or swelling the vinyl chloride polymer to prepare an aggregate of particles of the vinyl chloride polymer, dehydrating the aggregate and then drying it. The drying is carried out by using a fluidized drying machine under such conditions that the temperature of the vinyl chloride polymer is not more than 40.degree. C. in the constant rate period of drying and not more than 50.degree. C. in the falling rate period of drying.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: January 26, 1988
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Hiroshi Yoshida, Shiro Imaizumi, Masaaki Nishina
  • Patent number: 4604454
    Abstract: A method of recovering a vinyl chloride resin, which comprises mixing an aqueous dispersion of a vinyl chloride resin with an organic liquid which is difficultly soluble in water and does not dissolve nor swell the vinyl chloride resin to form a granular aggregate of the vinyl chloride resin, dehydrating the aggregate and drying it, wherein the granular aggregate before dehydration is adjusted to such a particle size that it contains not more than 20% by weight of particles having a particle diameter of not more than 100 microns.
    Type: Grant
    Filed: October 26, 1984
    Date of Patent: August 5, 1986
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Masaaki Nishina, Shiro Imaizumi, Osamu Ozaki