AQUEOUS PIGMENT DISPERSION AND INKJET RECORDING INK

• Main Authors: OCHI YASUO, KIMURA TOSHIHISA, OE NOBUHIRO, TANAKA HISAKAZU, UEMURA YUKIE
• Format: Patent
• Language: English; Japanese
• Published: 08.12.2016
• 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

PROBLEM TO BE SOLVED: To provide a method for producing an aqueous pigment dispersion using a quinacridone pigment for providing an inkjet recording aqueous ink which can be applied to a printer carrying a high resolution inkjet head, has reduced coarse particles and is excellent in discharge stability.SOLUTION: There are provided: a method for producing an aqueous pigment dispersion obtained by dispersing a polymer (A) having a number average molecular weight of 1000-6000 which has an anionic group, has a solubility in water of 0.1 g/100 ml or less and forms fine particles in water when the neutralization rate of the anionic group by a basic compound is set at 100%, a water-soluble organic solvent, a red azo pigment and a basic compound in water, wherein the amount of water at the initial stage of dispersion is less than 15 mass% with respect to the red azo pigment; and an inkjet recording ink using the aqueous pigment dispersion obtained by the production method.SELECTED DRAWING: None 【課題】 高解像度のインクジェットヘッドを搭載したプリンタにも適用可能な、粗大粒子が低減され吐出安定性に優れたインクジェット記録用水性インクを与えるキナクリドン系顔料を使用した水性顔料分散体の製造方法を提供する。【解決手段】 アニオン性基を有し、水への溶解度が０．１ｇ／１００ｍｌ以下であり、且つ、前記アニオン性基の塩基性化合物による中和率を１００％にしたときに水中で微粒子を形成する、数平均分子量が１０００〜６０００の範囲内であるポリマー（Ａ）と、水溶性有機溶剤と、赤色アゾ系顔料と、塩基性化合物とを水に分散する水性顔料分散体の製造方法であって、分散初期の水量が前記赤色アゾ系顔料に対し１５質量％未満である水性顔料分散体の製造方法、及び前記製造方法により得た水性顔料分散体を使用するインクジェット記録用インク。【選択図】 なし