Riso Kagaku Corporation

Tetsuo Hosoya

Toshihiro Endo

Marie Morinaga

Naoyuki Torita

Hiroshi Hayashi

Shinichiro Shimura

Naofumi Ezaki

Yoshifumi Watanabe

Kazuyuki Ando

Hikaru Sugiura

Asayo Nishimura

Akiko Yamamoto

Teruaki Okawa

Syotaro Kon

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

The method is a non-aqueous inkjet printing method including the steps of: ejecting droplets of a non-aqueous pigment ink containing at least a pigment and a non-aqueous solvent onto a surface of a printing medium to form dots composed of the non-aqueous pigment ink, and then ejecting droplets of a non-aqueous post-treatment liquid containing at least silica and an organic solvent toward the printing medium so that the droplets overlap with the dots composed of the non-aqueous pigment ink, wherein either of the non-aqueous pigment ink and the post-treatment liquid contains a water-soluble resin having an amino group.

Non-aqueous inkjet printing method

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

In a non-aqueous pigment ink that includes pigment, a non-aqueous solvent, and a non-aqueous resin that functions to disperse pigment dissolved in the non-aqueous solvent, the non-aqueous solvent includes a hydrocarbon based non polar solvent at 50% by mass or more with respect to the total amount of solvent. The non-aqueous resin is an acrylic polymer having a comb shaped structure, in which alkyl groups having carbon numbers from 8 to 18 and urethane groups form side chains on a (meth)acrylate main chain. The acrylic polymer is a copolymer of an alkyl(meth)acrylate (A) having alkyl groups with a carbon number from 8 to 18, a reactive (meth)acrylate (B) having functional groups that react with amino groups, and a monomer (C) having &#x3b2;-diketone groups or &#x3b2;-keto acid ester groups, into which the urethane groups are introduced by reactions between the functional groups that react with amino groups, amino alcohol, and a multivalent isocyanate compound. The mass ratio between the copolymer moiety and the urethane group moiety in the acrylic polymer is from 80:20 to 99:1.

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.

[Problem to be solved] A non-aqueous ink, which has excellent pigment dispersion stability and can achieve reduction or elimination of print-through, thereby achieving high print density, is disclosed. [Solution] The non-aqueous ink contains at least a pigment and an organic solvent, wherein the organic solvent contains a five-membered heterocyclic compound having a C&#x2550;O bond in an amount of 50 mass % or more of the organic solvent, and the content of a polymer component in the ink is 20 mass % or less relative to the pigment.

Non-aqueous ink

A the non-aqueous pigment ink containing at least a non-aqueous solvent and a pigment that is self-dispersed in the solvent, wherein the self-dispersed pigment is treated with a compound represented by R1-X or R2-Y-R3, where X is any of &#x2014;SH, &#x2014;NCO, &#x2014;NH2 and &#x2014;NHR (where R is an alkyl group), Y is any of &#x2014;CO&#x2014;O&#x2014;O&#x2014;CO&#x2014; and &#x2014;CO&#x2014;O&#x2014;O&#x2014;, R1, R2 and R3 are alkyl groups with a carbon number of 8-22, the alkyl groups may be linear or branched, and R2 and R3 may be the same with or different from each other. Alternatively, the non-aqueous inkjet ink may contain at least a non-aqueous solvent and a pigment that is self-dispersed in the solvent, wherein a content of a polymer component in the ink is 20 mass % or less relative to the pigment, and the ink has a specific heat of 3.0 J/(g&#xb7;K) or less.

A non-aqueous ink composition for inkjet printing, comprising 5 to 15% by mass of pigment relative to a mass of the non-aqueous ink composition, a pigment dispersant in such an amount that a mass ratio of the pigment dispersant to the pigment ranges from 0.2 to 2.0, and an organic solvent, the pigment dispersant comprising

Non-aqueous ink composition for inkjet printing

A non-aqueous pigment ink which suppresses show-through and improves the print density in printed items, and also exhibits excellent storage stability. The non-aqueous pigment ink comprises a pigment, a non-aqueous solvent, and non-aqueous resin dispersion particles having a pigment dispersion capability, wherein the non-aqueous resin dispersion particles comprise a urethane-modified alkyd resin formed from an oil-modified alkyd resin and/or fatty acid-modified alkyd resin having an oil length of not less than 50% by mass into which urethane groups have been introduced, and the urethane-modified alkyd resin is prepared by bonding an amino alcohol to double bonds within the oil-modified alkyd resin and/or fatty acid-modified alkyd resin, and then reacting the amino alcohol with a polyvalent isocyanate compound to introduce the urethane groups.

A non-aqueous ink composition for inkjet printing is provided, which comprises 0.01 to 10 wt % of at least one ionic substance (A) selected from the group consisting of quarterly ammonium salts, quarterly phosphonium salts, a combination of a fatty acid and/or an alkyl phosphate with an amine compound, and synergists, 0.1 to 20 wt % of an Calkyl(meth)acrylate copolymer (B) having 1 to 40 wt %, relative to a weight of the copolymer, of urethane moiety, 0.1 to 20 wt % of a pigment (C), and an organic solvent (D). The composition achieves excellent wiping durability and printed image density.

Ink composition for inkjet printing

A non-aqueous pigment ink comprising a pigment, a non-aqueous solvent, and non-aqueous resin dispersion microparticles having a pigment dispersion capability, wherein the non-aqueous resin dispersion microparticles are an acrylic polymer comprising an alkyl (meth)acrylate unit having an alkyl group of 12 or more carbon atoms and a (meth)acrylate unit having a urethane group. The acrylic polymer is a copolymer of a monomer mixture comprising an alkyl (meth)acrylate (A) having an alkyl group of 12 or more carbon atoms and a reactive (meth)acrylate (B) having a functional group capable of reacting with an amino group, wherein the urethane group is introduced by a reaction between the functional group capable of reacting with an amino group, an amino alcohol and a polyvalent isocyanate compound, and the mass ratio within the acrylic polymer between the copolymer portion and the introduced urethane group portions is within a range from 60:40 to 99:1.

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Ibaraki-ken, Japan

Tetsuo Hosoya