INK, INK CARTRIDGE, AND INKJET RECORDING METHOD

• Main Authors: YASUDA AKIKO, OGASAWARA MIKIFUMI, NAGAI SOICHI, FUJIOKA FUMIAKI, AIDA KEIGO
• Format: Patent
• Language: English; Japanese
• Published: 15.01.2015
• 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; LINING MACHINES; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; 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 an ink that gives sufficient optical density on both of a plain paper with high permeability and a plain paper with low permeability, and is further improved in resistance to bleeding and resistance to white blur.SOLUTION: The ink comprises a self-dispersion pigment, a surfactant, and a water-soluble organic solvent; and the ink has dynamic surface tension of, measured by a maximum bubble pressure method at 25°C, 46 mN/m or more at a life time of 50 msec, and 40 mN/m or less at a life time of 2,000 msec. The self-dispersion pigment includes a functional group containing a phosphonic acid group bonded to a particle surface, in which an amount of the functional groups introduced and bonded to the self-dispersion pigment is 0.33 mmol/g or less. The water-soluble organic solvent includes a water-soluble organic solvent (A); the water-soluble organic solvent (A) has a dissolution index of 0.8 or more with the surfactant; and the proportion of the water-soluble organic solvent (A) in the total content of the water-soluble organic solvent is 75 mass% or more. 【課題】浸透系及び上乗せ系の両方の普通紙における光学濃度を満足しつつ、耐ブリーディング性と耐白モヤ性をさらに向上させたインクを提供すること。【解決手段】自己分散顔料、界面活性剤、及び水溶性有機溶剤を含有するインクである。最大泡圧法により２５℃において測定されるインクの動的表面張力が、寿命時間５０ｍ秒において４６ｍＮ／ｍ以上、かつ、寿命時間２，０００ｍ秒において４０ｍＮ／ｍ以下であり、自己分散顔料が、ホスホン酸基を含む官能基が粒子表面に結合している顔料であり、かつ、自己分散顔料に結合している官能基の導入量が、０．３３ｍｍｏｌ／ｇ以下であり、水溶性有機溶剤が、水溶性有機溶剤Ａを含み、前記水溶性有機溶剤Ａの前記界面活性剤の溶解指数が０．８以上であり、かつ、水溶性有機溶剤の合計含有量に占める水溶性有機溶剤Ａの割合が７５質量％以上である。【選択図】なし