Dainichiseika Color & Chemicals Mfg. Co., Ltd.

Hitachi, Ltd.

Central Japan Railway Company

A & F Corporation

Tetsuo Fukuda

Shigeru Sakamoto

Hiroaki Saikatsu

Tohru Watanabe

Michiei Nakamura

Yoshio Abe

Mitsuo Yamazaki

Hisao Okamoto

Hajime Ito

Tadashi Fujii

Shiro Yamamiya

Kiyoshi Morita

Yuichi Ahiko

Kyohei Suzuki

Yukinobu Abe

Hiroki Shimoyama

Yuuji Ueno

Ichiro Fukuda

Akio Yoshida

Hiromitsu Yanagimoto

Masanori Takakamo

Yoshimasa Tsuchiya

Seishichi Sasaki

Hideto Sanui

Takeshi Uehara

Naonori Takami

Eiji Sato

Yasuhide Ueda

Rail vehicle

A dispersant for an organic pigment contains a compound represented by the following formula (1): wherein Rand Rmay be the same or different and each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a primary, secondary or tertiary amino group, an alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted phthalimidomethyl group, Rand Rmay be the same or different and each independently represents a hydrogen atom or a lower alkyl group, and n means an average number of introduced sulfonic groups and stands for a number of from 0.5 to 3; or at least one salt selected from the group consisting of its metal salt, ammonium salt, organic amine salt, and organic quaternary ammonium salt. Also disclosed are a readily-dispersing pigment composition, a pigment dispersion, a colored coating fluid for color filters, a fabrication process of a color filter and a color filter, all of which make use of the dispersant.

Dispersants for organic pigments

Pigment dispersions for color filters are composed of pigments, dispersants, film-forming resins and liquid media. The dispersants comprises compounds represented by the following formula (I):

Pigment dispersions for color filters, fabrication process of color filters, and color filters

Dispersants for organic pigments comprise compounds represented by the following formula (I):

Pigment dispersants, pigment dispersions and writing or recording pigment inks

A disazo pigment is prepared by coupling the tetrazo compound of 3,3'-dichlorobenzidine with an acetoacetanilide compound which is other than those represented by the below-described general formula (I) and is free of water-soluble groups. In the present invention, about 0.5-50 mole % of the acetoacetanilide compound is replaced by a compound represented by the following general formula (I): ##STR1## wherein R means a methyl, ethyl, propyl or butyl group or a substituted or unsubstituted phenyl group.

Disazo pigments having improved heat resistance using lower alkyl and

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Tokyo, Japan

Tetsuo Fukuda