Patents Assigned to Kanebo Rayon, Ltd.
  • Patent number: 5244734
    Abstract: A process for producing fine cellulose particles, which comprises(1) mixing viscose with a water-soluble anionic polymeric compound or polyethylene glycol or its derivative to form a dispersion of fine particles of viscose,(2) (i) heating the dispersion or mixing it with a coagulating agent to thereby coagulate the viscose in the dispersion, and thereafter neutralizing it with an acid to form fine particles of cellulose, or (ii) coagulating and neutralizing the dispersion with an acid to form fine particles of cellulose, and(3) thereafter, separating the fine particles of cellulose from the mother liquor. The fine cellulose particles(a) are composed substantially of II-type cellulose,(b) have a crystallinity, of 5 to 35% by weight,(c) are composed substantially of particles of not more than 20 micrometers, and(d) have a sharp particle size distribution.
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: September 14, 1993
    Assignees: Kanebo Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto
  • Patent number: 5064950
    Abstract: Fine crosslinked cellulose particles, wherein (1) said cellulose particles are composed substantially of a II-type cellulose crystalline phase and a non-crystalline cellulose phase, (2) said cellulose particles have a crystallinity, determined by X-ray diffractometry, of 5 to 35%, (3) said cellulose particles consist substantially of spherical to elongated spherical particles having an average particle diameter of not more than 300 .mu.m, and (4) said cellulose particles having an exclusion limit molecular weight by polyethylene glycol of not more than 4,000. The particles may have crosslinkage among the cellulose molecular chains in the non-crystalline phase.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: November 12, 1991
    Assignees: Kanebo, Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto, Hideo Yoshidome
  • Patent number: 4946953
    Abstract: Fine crosslinked cellulose particles, wherein (1) said cellulose particles are composed substantially of a II-type cellulose crystalline phase and a non-crystalline cellulose phase, (2) said cellulose particles have a crystallinity, determined by X-ray diffractometry, of 5 to 35%, (3) said cellulose particles consist substantially of spherical to elongated spherical particles having an average particle diameter of not more than 300 .mu.m, and (4) said cellulose particles having an exclusion limit molecular weight by polyethylene glycol of not more than 4,000. The particles may have crosslinkage among the cellulose molecular chains in the non-crystalline phase.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: August 7, 1990
    Assignees: Kanebo, Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto, Hideo Yoshidome
  • Patent number: 4902792
    Abstract: A process for producing fine cellulose particles, which comprises(1) mixing viscose with a water-soluble anionic polymeric compound or polyethylene glycol or its derivative to form a dispersion of fine particles of viscose,(2) (i) heating the dispersion or mixing it with a coagulating agent to thereby coagulate the viscose in the dispersion, and thereafter neutralizing it with an acid to form fine particles of cellulose, or (ii) coagulating and neutralizing the dispersion with an acid to form fine particles of cellulose, and(3) thereafter, separating the fine particles of cellulose from the motor liquor. The fine cellulose particles(a) are composed substantially of II-type cellulose,(b) have a crystallinity, of 5 to 35% by weight,(c) are composed substantially of particles of not more than 20 micrometers, and(d) have a sharp particle size distribution.
    Type: Grant
    Filed: December 30, 1987
    Date of Patent: February 20, 1990
    Assignees: Kanebo Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto