Patents Assigned to Tohoru Ricoh Co., Ltd.
  • Water-in-oil type emulsion ink for stencil printing
    Patent number: 6149720
    Abstract: A water-in-oil type emulsion ink composed of 10-90% by weight of an oil phase and 90-10% by weight of an aqueous phase. The oil phase contains a petroleum solvent having a kinematic viscosity of greater than 6-10 mm.sup.2 /s at 40.degree. C. and such a carbon content distribution that a naphthenic carbon content C.sub.N is at least 34%, an aromatic carbon content C.sub.A is 2-20% and a paraffinic carbon content CP is less than 55%.
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: November 21, 2000
    Assignee: Tohoru Ricoh Co., Ltd.
    Inventors: Keisuke Asada, Yukitaka Watarai, Koji Ono, Yoshihiko Sato