Dainichiseika Color & Chemicals Mfg. Co., Ltd.

Kyoto University

Naoyuki Sakai

Hiroyuki Shimanaka

Atsushi Nogami

Michiei Nakamura

Yoshiyuki Zama

Hideyuki Koiso

Kenji Ogawa

Yoshikazu Murakami

Dai Watanabe

Hisao Okamoto

Kazuo Kanou

Tohru Hosoda

Akio Yoshida

Shinya Tsuchida

Yoshinobu Tsujii

Shigeru Sakamoto

Atsushi Goto

Takeshi Fukuda

Sachio Yoshikawa

Hiroaki Saikatsu

Masanori Takakamo

Taiyo Aoyagi

Yoshimasa Tsuchiya

Seishichi Sasaki

Michiel Nakamura

Jiro Amano

Disclosed are an aqueous pigment dispersion containing at least a pigment, water, a high-molecular dispersant, and an alkali. The high-molecular dispersant is a diblock polymer having a formula (1) of A-B or a triblock polymer having a formula (2) of A-B-C. The diblock or triblock polymer is a diblock or triblock polymer obtained by polymerizing addition-polymerizable monomers with a radical generator while using an organic iodide as a polymerization initiating compound and an organic phosphorus compound, organic nitrogen compound or organic oxygen compound as a catalyst. Also disclosed are a production method and use of the aqueous pigment dispersion. With the high-molecular dispersant obtained by a simple living radical polymerization process free of the problems of conventional living radical polymerization and having a precisely-controlled molecular structure, the aqueous pigment dispersion can be obtained with the pigment dispersed in it.

Process for producing block polymer, coated pigment and aqueous pigment dispersion

This invention relates a copolymer (D) containing (A) methacrylic polymer units each having, at an end thereof, at least one group represented by the below-described formula (1) and (B) units of an aromatic vinyl monomer, wherein a weight ratio (A:B) of the units (A) to the units (B) is A:B=5 to 95:95 to 5; and its use. The present invention can provide inter alia a copolymer useful as a pigment dispersant or the like capable of affording pigment dispersions useful for inkjet inks, colors for color filters, and other applications. 

Copolymer and use thereof

An aqueous pigment dispersion is produced by ultrafinely dispersing a pigment dispersion mixture, which has been obtained by mixing at least a pigment and a dispersant in an aqueous medium, with microbeads having diameters of not smaller than 0.02 mm but smaller than 0.2 mm. A color composition for a color filter is produced by dispersing a mixture of a pigment, a dispersant, a resin varnish and a solvent with the microbeads in a mill.

Water-based pigment dispersions, inkjet recording inks, and color filters

A water-based pigment ink contains a pigment, a hydrophilic dispersant, an aqueous medium, an alkali agent for solubilizing the hydrophilic dispersant in the aqueous medium, and a hydrophilic compound having at least one structural unit of 'hydrophobic molecular chain-hydrophilic molecular chain-hydrophobic molecular chain' in a structure thereof. The water-based pigment ink is suited especially as an ink for ink-jet printers.

Water-based pigment inks, image recording method, and image recording system

Image-recording, hydrophilic colorants having an organic pigment linked to a hydrophilic compound through a linking group and which are capable of forming images excellent in print quality such as chroma, gloss, density, light fastness and abrasion fastness, and also as hydrophilic colorants capable of affording inks excellent in physical properties such as long-term storability and press stability are described.

Hydrophilic coloring matter for recording image, aqueous coloring agent for recording image, method and device for recording image

A process produces a sulfonated solid particle by burning sulfur to yield gaseous sulfur dioxide, subjecting the gaseous sulfur dioxide to catalytic oxidation to yield gaseous sulfur trioxide, and sulfonating a dry powdery or granular solid particle with the gaseous sulfur trioxide in a gas phase-solid phase reaction.

Process for producing sulfonated solid particles

An aqueous pigment dispersion is formed of a pigment, an aqueous medium and a dispersant resin. The dispersant resin contains a hydrophobic moiety and a hydrophilic moiety in its molecule. The hydrophobic moiety is a polyester linkage chain formed of ester linkages as primary linkages. The hydrophilic moiety is a water-soluble resin containing sulfonic groups or their salts. The water-soluble resin can be produced, for example, by reacting a polyol with maleic acid and/or fumaric acid to synthesize an unsaturated polyester resin and then adding acid sulfurous acid or its salt to the unsaturated polyester resin to form groups represented by the following formula (I): ##STR1## wherein M.sup.1 represents a hydrogen atom, an alkali metal, an ammonium group or a lower aliphatic quaternary ammonium group. The aqueous pigment dispersion is useful as a water-based ink for writing or recording equipments such as writing instruments, printers, copying machines, fax machines and printing machines.

Aqueous pigment dispersion, water-soluble resin, production process of

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Tokyo, Japan

Naoyuki Sakai