Patents Assigned to NMB Co., Ltd.
  • Patent number: 6642320
    Abstract: A multi-functional cement dispersant contains a graft copolymer obtained by a graft reaction of one or more selected from polyoxyalkylene monoalkylester, polyoxyalkylene monoalkylether and polypropyleneglycol of specified kinds to a copolymer obtained by radical polymerization of a mixture of radical polymerizable monomers containing maleic anhydride and monomers of a specified kind at a specified ratio. Hydraulic cement compositions produced with such a multi-functional cement dispersant have a superior fluidity with reduced loss over time and hardened objects produced from such a composition exhibit a superior early strength and have a low dry shrinkage and a high resistance against freezing and thawing.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: November 4, 2003
    Assignees: Taiheiyo Cement Kabushiki Kaisha, NMB Co., Ltd., Takemoto Yushi Kabushiki Kaisha
    Inventors: Hiroshi Nakanishi, Masaki Ishimori, Minoru Yaguchi, Takumi Sugamata, Tomomi Sugiyama, Mitsuo Kinoshita, Shinji Tamaki