Abstract: A dispersant for an organic pigment contains a compound represented by the following formula (1): wherein R1 and R2 may 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, R3 and R4 may 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.

Abstract: 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.

Abstract: Image-recording, hydrophilic colorants represented by the below-described formula (1) are disclosed. These colorants can be provided as colorants 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. [organic pigment]?[linking group]?[hydrophilic compound]??(1) wherein the [organic pigment] is a hydrophobic pigment having no hydrophilic group by itself, the [linking group] is a group linking the [organic pigment] and the [hydrophilic compound] with each other and blocking an effect of the [hydrophilic compound] on the [organic pigment], and the [hydrophilic compound] is an anionic, cationic and/or nonionic, hydrophilic compound.

Abstract: A dispersant for an organic pigment contains a compound represented by the following formula (1): wherein R1 and R2 may 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, R3 and R4 may 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.