Dic Corporation

Dainippon Ink and Chemicals, Incorporated

Shinichi Okada

Yoshinosuke Shimamura

Yoshitaka Saito

Kumiko Iizasa

Katsunori Oba

Hiroyuki Buei

Soetrisno Misawa

Masahiro Kido

Hiroshi Harada

Sadahiro Inoue

Yukihiko Kawaharada

Atsuo Kobayashi

Kazuhiro Kaneko

Hiromichi Arakawa

Kenji Nasu

Takashi Yoshinari

Hideki Gambayashi

Hideaki Kaji

Ritsuko Small

Kyouko Takashima

Ryouta Hibino

Ryota Hibino

Provided is a method for producing an aqueous pigment dispersion including a step of dispersing a mixture containing a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment into water. The step of dispersing includes Step 1 of kneading a mixture which contains a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment, and which contains no water or water equal to or less than 30% by mass with respect to a solid content thereof, and Step 2 of dispersing a kneaded material obtained in Step 1 into water.

Method for manufacturing aqueous pigment dispersion and aqueous ink for inkjet recording

A method for producing an aqueous pigment dispersion liquid, including: a kneading step of kneading a mixture of a quinacridone pigment (a), a pigment derivative (b), an organic high-molecular compound having an anionic group (c), a basic compound (d), and an acetylene glycol surfactant (e) in a closed kneader to prepare a pigment-kneaded material having a solid content in the range of 50% to 80% by mass; and a step of diluting the pigment-kneaded material with an aqueous medium. A method for producing a water-based ink for ink jet recording, including a step of diluting the aqueous pigment dispersion liquid with an aqueous medium.

Methods for producing aqueous pigment dispersion liquid and water-based ink for ink jet recording

A highly efficient method is provided for producing a water-based ink for ink jet recording with which the number of coarse particles in a water-based pigment dispersion liquid is significantly reduced, dispersed particles are made finer, the dispersion stability is improved, the storage stability is improved, and high discharge stability is achieved when a water-based ink for ink jet recording is produced. Particularly, provided is a method for producing a water-based pigment dispersion liquid, the method including kneading a mixture containing a quinacridone type pigment (a), a styrene-acrylic acid type copolymer (c), a basic compound (d), and a polyoxyalkylene glycol or its derivative (e) to prepare a pigment dispersion that is solid at room temperature and mixing a aqueous medium and the pigment dispersion to decrease the viscosity and liquefy the pigment dispersion.

Method for producing water-based pigment dispersion liquid and water-based ink for ink jet recording

Disclosed are an ink jet recording water-based ink having excellent long-term storage stability and ejection stability at a pigment concentration greater than or equal to a certain level and a simple and efficient method for producing such a water-based ink. The present invention provides an ink jet recording water-based ink in which the total content of polyvalent metals as impurities in the water-based ink is not more than 1.2 ppm in terms of 1 mass % of a pigment concentration. Furthermore, the present invention provides a method for producing an ink jet recording water-based ink; the method enables efficient production of the above-mentioned ink jet recording water-based ink through a contact treatment with a particulate chelating resin in which each resin particle contains both an alkali metal-bonded chelating group and a hydrogen-bonded chelating group.

Ink jet recording water-based ink and method for producing the same

A resin for aqueous pigment dispersion that allows the production of an aqueous pigment dispersion for ink jet recording that contains only a few coarse particles and has excellent ejection stability, an aqueous pigment dispersion containing the resin for aqueous pigment dispersion, an ink jet recording ink, and a method for producing an aqueous pigment dispersion. A resin for aqueous pigment dispersion produced by copolymerization of a composition that contains (a) one or two or more compounds selected from the group consisting of alkenylsuccinic acids, alkenylsuccinic anhydrides, alkylsuccinic acids, and alkylsuccinic anhydrides, and (b) a styrene monomer, wherein the (a) component constitutes 5% by mass or more and the (b) component constitutes 30% by mass or more of the total amount of all the monomer component(s) and the (a) component of the composition.

Resin for aqueous pigment dispersion, aqueous pigment dispersion, ink jet recording ink, and method for producing aqueous pigment dispersion

A process is provided for producing aqueous pigment dispersions for ink-jet recording in which fine pigments are stably dispersed and such a state can be maintained for a long period of storing. Moreover, a process is provided for producing aqueous pigment dispersions for ink-jet recording in which the time required for production such as dispersing time is short, and the production efficiency is high. The process for producing aqueous pigment dispersions for ink-jet recording includes a first step of kneading (1) a styrene-acrylic type resin with a styrene type monomer unit of 50 to 90 mass %, and at least one unit selected from an acrylic monomer unit and methacrylic monomer unit, having an acid value of 50 to 300, (2) a pigment, (3) a basic compound, and (4) a humectant to produce a solid colored kneaded product, and a second step of dispersing the solid colored kneaded product in an aqueous medium comprising water or water and humectant.

Process for producing aqueous pigment dispersions for ink-jet recording

Disclosed are an aqueous pigment dispersion for inkjet ink, a method for producing the same, and an ink composition for inkjet recording which mainly contains the aqueous pigment dispersion for inkjet ink. The method for producing the aqueous pigment dispersion for inkjet ink is characterized by comprising a kneading step wherein a mixture including a styrene resin, a quinacridone pigment, a phthalimidomethylated quinacridone compound, an alkali metal hydroxide and a wetting agent is kneaded for producing a solid colored kneaded material, and a dispersing step wherein the thus-obtained solid colored kneaded material is dispersed into an aqueous medium.

Water-based pigment dispersion for ink-jet recording, ink composition for ink-jet recording and method of producing the same

The present invention provides an electrophotographic photoreceptor which can be prepared so easily as to exhibit a photosensitivity well-adjusted for the respective type of machine in the dip coating method, which is an ordinary method for the preparation of an electrophotographic photoreceptor. A novel electrophotographic photoreceptor is provided comprising a charge-transporting layer and a charge-generating layer provided on an electrically-conductive support, wherein the charge-generating layer is a layer comprising a charge-generating material containing a phthalocyanine compound represented by the following general formula (1) dispersed in a resin: ##STR1## wherein Ar.sup.1 and Ar.sup.2 each independently represent an orthophenylene group which may have a substituent; and Pc represents an unsubstituted or substituted phthalocyanine residue.

Phthalocyanine compound and electrophotographic photoreceptor comprising

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Kita-adachi-gun, Japan

Shinichi Okada