Kao Corporation

Think Laboratory Co., Ltd.

Nippon Paper Industries Co., Ltd.

Yasufumi Ueda

Ryuma Mizushima

Yuta Matsumoto

Tatsuo Shigeta

Kazuki Watanabe

Takahiro Sato

Takayuki Suzuki

Tomohide Yoshida

Koji Kutsuwa

Yuki Ozaki

Takuto Matsuzono

Yusuke Shimizu

Teruyuki Fukuda

Isao Tsuru

Kaname Mitsuyoshi

Hironobu Fukuroi

Masaaki Nakano

Takako Yamamoto

Erika Maekawa

The present invention relates to an aqueous gravure ink containing a pigment, a water-soluble organic solvent, a surfactant and water, in which the water-soluble organic solvent contains a glycol ether having a boiling point of 100 to 260° C.; the surfactant contains a silicone-based surfactant containing a specific constitutional unit; a content of the water-soluble organic solvent in the ink is 1 to 10% by mass; and a content of water in the ink is 50 to 80% by mass. This ink exhibits a less burden on the environments, and is excellent in optical density and drying properties.

Aqueous gravure printing ink

The present invention relates to an aqueous gravure ink containing a pigment, a polymer, a water-soluble organic solvent, a surfactant and water, in which the water-soluble organic solvent contains a glycol ether having a boiling point of from 100 to 260&#xb0; C., and a content of the glycol ether in the ink is from 1 to 10% by mass; a total content of the water-soluble organic solvent in the ink is not more than 15% by mass; the surfactant contains an acetylene glycol-based surfactant; and a content of water in the ink is from 50 to 70% by mass.

Aqueous gravure ink

The present invention relates to a process for producing a dispersion of white fine particles from which a white ink that is capable of exhibiting excellent hiding power, rub fastness and water resistance even when printed on a low-water absorbing printing medium can be obtained by incorporating the dispersion of the white fine particles into the ink, and a water-based ink for ink-jet printing which contains the white fine particles. The present invention provides [1] a process for producing a dispersion of white fine particles, including step 1 of mixing titanium oxide and a polymer dispersant at a pH value that is not less than an acid dissociation exponent (pKa) of at least a part of an acid component of the polymer dispersant to thereby obtain a titanium oxide dispersion, in which an isoelectric point (A) of the titanium oxide and the acid dissociation exponent (pKa) (B) of the polymer dispersant satisfy a relationship represented by the formula: A&#x2212;B&#x2265;0, the polymer dispersant contains a constitutional unit derived from a hydrophobic monomer, and a volume median particle size (D) of particles in the titanium oxide dispersion is from 150 to 500 nm; and step 2 of adding a polymerizable monomer to the titanium oxide dispersion obtained in the step 1 to subject the polymerizable monomer to polymerization reaction, thereby obtaining the dispersion of the white fine particles, and [2] a water-based ink for ink-jet printing which contains the white fine particles obtained above.

Method for manufacturing white fine particle dispersion

The present invention relates to a cleaning liquid for a water-based ink that contains a pigment and a water-insoluble polymer, said cleaning liquid containing (A) an acetylene glycol having an average molar number of addition of EO of 0 to 2 mol, (B) at least one compound selected from the group consisting of an acetylene glycol having an average molar number of addition of EO of not less than 4 mol and a polyethylene glycol alkyl ether containing an alkyl group having not less than 8 carbon atoms, (C) a water-soluble organic solvent and water, in which the water-soluble organic solvent (C) contains at least one water-soluble organic solvent having a boiling point of not lower than 90&#xb0; C.; a boiling point of the water-soluble organic solvent (C) is not higher than 250&#xb0; C. in terms of a weighted mean value thereof; and a content of the water-soluble organic solvent (C) in the cleaning liquid is not more than 20% by mass; a process for producing the cleaning liquid; and a method of cleaning a water-based ink using the cleaning liquid.

Cleaning liquid for aqueous ink comprising an acetylene glycol-based surfactant

The present invention relates to a gravure printing method of conducting printing on a printing substrate with an aqueous ink reserved in an ink pan using a furnisher roll, a gravure roll, a doctor blade and a nip roll, in which the aqueous ink contains a pigment, a polymer, an organic solvent, a surfactant and water; a content of organic solvent components of the organic solvent which have a boiling point of 100 to 260&#xb0; C. in the aqueous ink is not less than 0.3% by mass and not more than 12% by mass; an average particle size of particles of the pigment is from 120 to 350 nm; and an arithmetic mean roughness (Ra) of a plate surface of the gravure roll is from 10 to 140 nm. According to the present invention, it is possible to improve transfer properties of the ink to the printing substrate such as a resin film, etc., and suppress fogging on the plate surface.

Gravure printing method

The present invention relates to an ink-jet printing method including the step of ejecting a water-based ink containing pigment-containing water-insoluble polymer particles and water onto a printing medium to print characters or images on the printing medium, in which the pigment is at least one pigment selected from the group consisting of C.I. Pigment Red 177, C.I. Pigment Red 254, C.I. Pigment Green 7, C.I. Pigment Green 36 and C.I. Pigment Blue 15:6; the water-insoluble polymer constituting the particles contains a constitutional unit derived from an ionic monomer, a constitutional unit derived from a hydrophobic monomer and a constitutional unit derived from a monomer capable of forming a graft chain; and the printing medium is a low-water absorbing printing medium.

Inkjet recording method

The present invention relates to white fine particles from which a white ink that is capable of satisfying both of high hiding power and good bending resistance in a printed material can be obtained, and further relates to white fine particles from which an ink that is capable of satisfying not only excellent fixing properties even when printed on a non-liquid absorbing printing medium such as a resin film, but also suppression of increase in viscosity of the ink and at the same time good deinking properties at a high level can be obtained. The present invention provides [1] white fine particles containing titanium oxide and a polymer component with which the titanium oxide is encapsulated, in which a titanium atomic fraction of a surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by X-ray photoelectron spectroscopy (XPS) is not more than 7 atomic %, [2] a water-based ink containing the aforementioned white fine particles, in which the titanium atomic fraction of the surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by XPS is not more than 5 atomic %, and [3] a process for producing a dispersion of white fine particles, including step 1 of mixing titanium oxide and a polymer dispersant to obtain a titanium oxide dispersion and step 2 of adding a polymerizable monomer to the thus obtained titanium oxide dispersion to subject the polymerizable monomer to polymerization reaction, thereby obtaining the dispersion of the white fine particles, in which a titanium atomic fraction of a surface of the respective white fine particles as measured at a photoelectron takeoff angle of 45&#xb0; by XPS is not more than 7 atomic %.

Fine white particles comprising polymer-encapsulated titanium oxide

The present invention relates to a pigment water dispersion containing a pigment, a crosslinked polymer and water, in which the crosslinked polymer is prepared by crosslinking a carboxy group-containing polymer with a crosslinking agent, and has an acid value of not less than 70 mgKOH/g and not more than 300 mgKOH/g; and the pigment water dispersion further contains a formaldehyde-releasing compound. The pigment water dispersion of the present invention is excellent in storage stability even when being stored under high-temperature conditions for a long period of time.

Aqueous pigment dispersion

The present invention relates to [1] a process for producing a printed material, including step 1 of subjecting an image-bearing surface of a printed recording medium 1' on which characters or images are formed by analog printing to discharge treatment under specific conditions to obtain a printed recording medium 1, and step 2 of further forming characters or images on the image-bearing surface of the printed recording medium 1 by ink-jet printing using a water-based ink to obtain the printed material, [2] an ink-jet printing method including the step of ejecting a water-based ink onto a printed recording medium 1 by an ink-jetting method to form characters or images thereon, in which the printed recording medium 1 has an image-bearing surface on which characters or images are formed by analog printing, and the image-bearing surface is subjected to discharge treatment under the specific conditions, [3] a recording medium for ink-jet printing, including an image-bearing surface on which characters or images are formed by analog printing and which is subjected to discharge treatment, in which a surface free energy of the image-bearing surface after being subjected to the discharge treatment is not less than 30 mN/m, and [4] a printed material including an image-bearing surface on which characters or images are formed by analog printing and then on at least a part of which characters or images are further formed by ink-jet printing using a water-based ink, in which the image-bearing surface after forming the characters or images thereon by the analog printing is subjected to discharge treatment, and a surface free energy of the image-bearing surface after being subjected to the discharge treatment is not less than 30 mN/m.

Method for manufacturing printed matter

Provided is a gravure printing method by which high printing density and excellent highlight suitability are obtained, even if a gravure plate having high resolution and reduced thickness is used. The gravure printing method comprises: using an aqueous ink having a Zahn cup #3 viscosity at 20&#xb0; C. of 11.0 seconds or more and 20.0 seconds or less, and having an evaporation rate of 30 mass % or less in a drying test, the drying test involving drying 1 g of the ink at a temperature of 40&#xb0; C. and an air flow of 1,400 L/min for 30 minutes; and transferring 1 ml/mor more and 7 ml/mor less of the ink onto a printing medium.

Provided is an aqueous gravure ink that is environmentally friendly, allows high-resolution printing by virtue of its excellent highlight suitability, and is excellent in drying property. The aqueous gravure ink comprises: a pigment; a polymer; a water-soluble organic solvent; a surfactant; and water, in which the water-soluble organic solvent has a boiling point of 100&#xb0; C. or more and 260&#xb0; C. or less, in which a content of the water-soluble organic solvent in the aqueous gravure ink is 10 mass % or more and 35 mass % or less, and in which a content of the water in the aqueous gravure ink is 50 mass % or more and 70 mass % or less.

The present invention relates to an ink-jet printing method that is capable of obtaining good printed materials that are free of occurrence of color migration and deformation of a printing medium even when printed on a transparent resin printing medium using a water-based ink containing a white ink, and a black or chromatic ink. The present invention provides an ink-jet printing method including the step of ejecting a water-based ink onto a printing medium using a printing apparatus to print characters or images on the printing medium, said printing apparatus including an ink-jet printing head that ejects the water-based ink onto the printing medium that is transported in a feeding direction thereof; and an drying mechanism that is disposed on a downstream side in a feeding direction of the printing medium, in which the printing medium is in the form of a transparent resin printing medium, and the water-based ink includes a white ink, and a black or chromatic ink, and in which the drying mechanism blows a superheated steam that is heated to a temperature of 100 to 180&#xb0; C. onto at least one of a printing surface and an opposite surface of the printing medium.

Ink jet recording method

The present invention relates to an ink-jet printing method that is capable of obtaining good printed materials that are free of occurrence of color migration and deformation of a printing medium even when printed on a resin printing medium. The present invention provides an ink-jet printing method using a water-based ink containing a black ink, a chromatic ink and a white ink which each contain a pigment (A), an organic solvent (C) having a boiling point of not lower than 90&#xb0; C. and lower than 250&#xb0; C., and water, said method including step 1 of ejecting at least one water-based ink selected from the group consisting of the black ink and the chromatic ink onto a transparent resin printing medium to print an image 1 on the printing medium; step 2 of ejecting the white ink onto the resulting image 1 to print a white image that covers the image 1 on the printing medium; and step 3 of heating and drying the resulting printed material from a side of a surface of the printing medium on which the white image is formed, using an infrared heater.

An inkjet recording medium having an ink receiving layer containing an inorganic pigment, starch, and copolymer latex on at least one surface of a base, characterized in that the inorganic pigment contains engineered calcium carbonate and kaolin, an amount of the engineered calcium carbonate is from 50% by weight or more to less than 80% by weight and an amount of the kaolin is from 10% by weight or more to less than 50% by weight with respect to a total amount of the inorganic pigment, and from 1 parts by weight or more to 10 parts by weight or less of an organic pigment having a glass transition temperature (Tg) of 20&#xb0; C. or more is contained in the ink receiving layer with respect to 100 parts by weight of the inorganic pigment.

Inkjet recording medium and inkjet recording method

The present invention relates to an ink-jet printing apparatus that is capable of obtaining printed materials that are free of occurrence of color migration and have good appearance even when printed on a resin printing medium using a water-based ink, and an ink-jet printing method. The present invention provides an ink-jet printing apparatus including an ink-jet printing head that ejects a water-based ink onto a resin printing medium that is transported in a feeding direction thereof, and an under heater that heats the printing medium from a rear side surface of the printing medium opposed to a front side surface thereof which faces to the ink-jet printing head, in which the under heater is disposed at a position spaced at a distance of from 0.05 to 3.0 mm apart from the rear side surface of the printing medium upon printing, and an ink-jet printing method using the ink-jet printing apparatus.

Growing community of inventors

Wakayama, Japan

Yasufumi Ueda