Patents Examined by Vu Nguyuen
  • Patent number: 7691193
    Abstract: Disclosed are an aqueous pigment dispersion for inkjet ink, a method for producing the same, and an ink composition for inkjet recording which mainly contains the aqueous pigment dispersion for inkjet ink. The method for producing the aqueous pigment dispersion for inkjet ink is characterized by comprising a kneading step wherein a mixture including a styrene resin, a quinacridone pigment, a phthalimidomethylated quinacridone compound, an alkali metal hydroxide and a wetting agent is kneaded for producing a solid colored kneaded material, and a dispersing step wherein the thus-obtained solid colored kneaded material is dispersed into an aqueous medium.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: April 6, 2010
    Assignee: Dainippon Ink & Chemicals, Inc.
    Inventors: Shinichi Okada, Kyouko Takashima, Ryouta Hibino