METHOD FOR PRODUCING WATER-BASED PIGMENT DISPERSION LIQUID AND WATER-BASED INK FOR INK JET RECORDING

• Main Authors: KIDO, MASAHIRO, OKADA, SHINICHI, KOBAYASHI, ATSUO, MISAWA, SOETRISNO
• Format: Patent
• Language: English; French
• Published: 16.12.2014
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; CORRECTING FLUIDS; CORRECTION OF TYPOGRAPHICAL ERRORS; DYES; FILLING PASTES; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; INKS; LAKES; LINING MACHINES; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; MORDANTS; NATURAL RESINS; ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; POLISHES; PRINTING; SELECTIVE PRINTING MECHANISMS; STAMPS; TRANSPORTING; TYPEWRITERS; USE OF MATERIALS THEREFOR; WOODSTAINS

An object is to provide a highly efficient method for producing a water-based ink for ink jet recording with which the number of coarse particles in a water-based pigment dispersion liquid is significantly reduced, dispersed particles are made finer, the dispersion stability is improved, the storage stability is improved, and high discharge stability is achieved when a water-based ink for ink jet recording is produced. To achieve the object, provided is a method for producing a water-based pigment dispersion liquid, the method including a kneading step of kneading a mixture containing a quinacridone type pigment (a), a styrene-acrylic acid type copolymer (c), a basic compound (d), and a polyoxyalkylene glycol or its derivative (e) to prepare a pigment dispersion that is solid at room temperature and a mixing step of mixing an aqueous medium and the pigment dispersion to decrease the viscosity and liquefy the pigment dispersion.