Riso Kagaku Corporation

Tokyo University of Science Foundation

Naofumi Ezaki

Shinichiro Shimura

Yoshifumi Watanabe

Kazuyuki Ando

Tetsuo Hosoya

Mitsuko Kitanohara

Toshihiro Endo

Marie Morinaga

Manami Shimizu

Shinsuke Ozawa

Naoyuki Torita

Tomohiro Matsuzawa

Hiroshi Hayashi

Yoshihiro Saito

Yasuo Yamamoto

Kenji Yamada

Hikaru Sugiura

Hidenori Otsuka

Teruaki Okawa

Tetsuya Shiraishi

Masayuki Fukaishi

Takashi Ishizuka

Koji Ueno

Tsukasa Hamada

An oil-based inkjet ink is disclosed that contains a pigment, a dispersant formed with an acidic resin, a low-molecular weight amine compound and a basic polymer, and a non-aqueous solvent. A method for producing an oil-based inkjet ink and a method for producing a dispersant is also disclosed.

Oil-based inkjet ink, method for producing oil-based inkjet ink and method for producing dispersant

An oil-based magnetic ink can be provided that has low viscosity and improved storage stability. Specifically disclosed is an oil-based magnetic ink containing a magnetic pigment that contains a ferrite, a pigment dispersant A that has an acid value but has no base value, a pigment dispersant B that has an acid value and a base value, and a non-aqueous solvent. One example of the pigment dispersant A is at least one compound selected from the group consisting of hydroxystearic acid and polyhydroxystearic acid. One example of the pigment dispersant B has an acid value of at least 5 mgKOH/g.

Oil-based magnetic ink

An oil-based inkjet ink is disclosed that contains a colorant, an oil-soluble resin that is an acrylic-based polymer having a side chain containing a polydimethylsiloxane structure, and a non-aqueous solvent. A method for producing an oil-based inkjet ink is also disclosed.

Oil-based inkjet ink and method for producing oil-based inkjet ink

An oil-based inkjet ink is disclosed that contains colored resin particles, an ionic dispersant and a non-aqueous solvent, wherein the colored resin particles contain a colorant and a urethane-urea resin. A method for producing an oil-based inkjet ink is also disclosed.

A nozzle plate which exhibits excellent ink repellency and excellent durability to wiping, even when used with an ink that adheres readily to the nozzle plate is provided. A method for forming a silicone-based cured film on the ink discharge surface of a nozzle plate for an inkjet printer, the method comprising: (1) a step of preparing a condensation-type silicone composition containing at least one compound selected from the group consisting of bismuth compounds and cyclic amidine compounds, (2) a step of applying this condensation-type silicone composition to the ink discharge surface of the nozzle plate to form a coating film, and (3) a step of heating and curing this coating film.

Method for forming silicone-based cured film on ink discharge surface of nozzle plate for inkjet printer, and nozzle plate

A non-aqueous pigment ink includes a pigment, a non-aqueous solvent, a non-water-soluble resin and a water-soluble resin, wherein the non-water-soluble resin is an acrylic polymer formed by a copolymer of a monomer mixture containing at least an alkyl (meth)acrylate (A) having a C8 to C18 alkyl group and a monomer (B) having a &#x3b2;-diketone group or &#x3b2;-keto acid ester group.

Non-aqueous pigment ink

A non-aqueous pigment ink includes a pigment, a non-aqueous solvent, a non-water-soluble resin and a water-soluble resin, wherein the non-water-soluble resin is an acrylic polymer formed by a copolymer of a monomer mixture containing at least an alkyl(meth)acrylate (A) having a C8 to C18 alkyl group and a monomer (B) having a &#x3b2;-diketone group or &#x3b2;-keto acid ester group.

A water-in-oil (W/O) emulsion ink which is suitable for use in inkjet printing and is superior in ejection performance and storage stability and low in viscosity is provided. A water-in-oil (W/O) emulsion ink which comprises a polyglycerin with a polymerization degree of not less than 3 in a water phase is provided. As an emulsifier, a polyglycerin fatty acid ester with an HLB value of 7-14 in which fatty acid moiety is oleic acid or isostearic acid, or a polyoxyethylene sorbit fatty acid ester is preferably used. The concentration of the polyglycerin in the water phase is preferably 10-70 mass % relative to 100 mass % of the whole water phase. The polymerization degree of the polyglycerin is preferably not less than 4.

W/O emulsion ink for inkjet

A water-in-oil (W/O) emulsion ink having an ejection performance suitable for inkjet printing and superior storage stability at high temperature includes as emulsifiers, a polyglyceryl fatty acid ester (A) having a fatty acid moiety is isostearic acid or oleic acid with an HLB value of 7-14 and a glycerol polymerization degree of not less than 4, at least one nonionic surfactant (B) selected from (B-a) an esterification product of an organic compound with 3-5 hydroxyl groups and a fatty acid having 18 carbon atoms, (B-b) an alkyl glyceryl ether, (B-c) a diterpene alcohol and (B-d) a sucrose fatty acid ester having an HLB value of not more than 13.

A water-in-oil (W/O) emulsion ink which is suitable for use in inkjet printing and superior in ejection performance and storage stability is provided. A polyglycerin fatty acid ester which fatty acid moiety is oleic acid or isostearic acid and which has an HLB value of 7-14, is used as an emulsifier. The polyglycerin fatty acid ester preferably has a glycerin polymerization degree of 4-20 and preferably contains 1-3 fatty acids per one molecule thereof. The polyglycerin fatty acid ester has an organic value of preferably 550-2300 and an inorganic value of preferably 600-2500. Preferably, the emulsion ink comprises 40-99 mass % of the oil phase and 60-1 mass % of the water phase, and comprises 0.5-40 mass % of the polyglycerin fatty acid ester relative to the total amount of the ink. The water phase may contain a dye and optionally a solubilizer such as an amine based surfactant.

A non-aqueous inkjet ink comprising a coloring material and a water-insoluble solvent, wherein the coloring material is water-soluble or water-dispersible, and the amount of water within the ink is less than the amount of water required to dissolve or disperse the coloring material.

Non-aqueous inkjet ink

An inkjet ink that prevents paper deformation such as curling, and also exhibits favorable pigment dispersibility. The inkjet ink includes at least a pigment, water, a water-soluble organic solvent having an &#x3b1; value of not more than 65, and a dispersant, wherein the dispersant is a copolymer having a unit A represented by general formula (a) shown below and a unit B represented by general formula (b) shown below, and the mass ratio between the water-soluble organic solvent and the water satisfies (water-soluble organic solvent)/water=5/5 to 8/2. [In general formula (a), Rrepresents a hydrogen atom or a lower alkyl group, and m represents an integer of 1 to 3.] [In general formula (b), Rand Reach represents a hydrogen atom or a lower alkyl group, wherein Rand Rmay be the same or different, and n represents an integer of 1 to 250.]

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Ibaraki, Japan

Naofumi Ezaki