METHOD FOR MANUFACTURING A WATER-BASED INK FOR INKJET PRINTING AND A WATER-BASED PIGMENT DISPERSION LIQUID

• Main Authors: OKADA SHINICHI, KOBAYASHI ATSUO, MISAWA SOETRISNO, KIDO MASAHIRO
• Format: Patent
• Language: Chinese; English
• Published: 30.05.2012
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COLOUR PRINTING; 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; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; SELECTIVE PRINTING MECHANISMS; STAMPS; TRANSPORTING; TYPEWRITERS; USE OF MATERIALS THEREFOR; WOODSTAINS

Provided is a highly efficient method for manufacturing a water-based pigment dispersion liquid. Said method substantially reduces the number of coarse particles in the manufactured water-based pigment dispersion liquid, reduces the size of the dispersed particles, and improves the stability of the dispersion, thereby improving storage stability and allowing the production of a water-based ink for inkjet printing, said ink having good discharge stability. The provided method is characterized by the inclusion of: a kneading step in which a pigment dispersion that is solid at room temperature is produced by kneading a mixture containing a quinacridone pigment (a), a styrene-acrylate copolymer (c), a basic compound (d), and either a polyoxyalkylene glycol or a derivative thereof (e); and a mixing step in which an aqueous medium is mixed with the aforementioned pigment dispersion, reducing the viscosity of and liquefying said pigment dispersion.