JP-2026074680-A - Colored resin particle dispersion for inkjet and aqueous ink composition for inkjet

Abstract

[Problem] To provide a colored resin particle dispersion and an aqueous ink composition suitable for inkjet printing. [Solution] The inkjet colored resin particle dispersion of the present invention is characterized in that colored resin particles, each composed of at least a (meth)acrylic acid ester monomer represented by the following general formula (X) and at least one dye selected from the following group A, are dispersed in water. [In the formula, A is a hydrogen atom (H) or a methyl group ( CH3 ), and R is a hydrogen atom (H), an alkyl group having 1 to 22 carbon atoms, etc.] Group A: Basic dyes, oil-soluble dyes, acidic dyes, and salt-forming dyes which are salt-forming products of basic dyes. The aqueous inkjet ink composition of the present invention is characterized by containing an inkjet colored resin particle dispersion having the above composition. [Selection Diagram] None

Inventors

• 羽賀 久人

Assignees

• 三菱鉛筆株式会社

Dates

Publication Date

20260507

Application Date

20241021

Claims (4)

1. An inkjet-compatible colored resin particle dispersion characterized in that colored resin particles, each composed of at least a (meth)acrylic acid ester monomer represented by the following general formula (X) and at least one dye selected from the following group A, are dispersed in water. [In the above formula (I), A is a hydrogen atom (H) or a methyl group ( CH3 ), and R represents a substituent having a hydrogen atom (H), an alkyl group having 1 to 22 carbon atoms, or a polyalkylene glycol chain having 2 to 18 carbon atoms. The substituent having an alkyl group or a polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, an alkoxy group having 1 to 18 carbon atoms, a perfluoroalkyl group having 1 to 18 carbon atoms, or a trialkoxysilyl group as a substituent.] Group A: Basic dyes, oil-soluble dyes, acid dyes, and salt-forming dyes which are salt-forming products of basic dyes.
2. The inkjet-use colored resin particle dispersion according to claim 1, characterized in that the colored resin particles further contain terpene phenol resin.
3. The inkjet-compatible colored resin particle dispersion according to claim 1 or 2, characterized in that the average particle size of the colored resin particles is 10 to 800 nm.
4. An aqueous inkjet ink composition characterized by comprising the inkjet-compatible colored resin particle dispersion described in claim 1 or 2.

Description

This invention relates to a colored resin particle dispersion for inkjet printing and an aqueous ink composition for inkjet printing. Conventionally, inkjet colorants have included those primarily composed of pigments such as carbon black, those containing dissolved dyes, and those using colored resin particles. Colored resin particles are created by encapsulating colorants in resin to form colored resin particles, thereby utilizing the image-related characteristics of the colorants while improving water resistance and color development. Ideally, the resin should possess properties that impart water resistance, lightfastness, long-term stability, and color development to the ink. Conventional colored resin particle dispersions and aqueous ink compositions for inkjet printers include, for example, 1) An inkjet ink comprising colored resin particles and water as a dispersion medium for dispersing the colored resin particles, wherein the colored resin particles are produced by combining the dispersed phase in an emulsion in which a dispersed phase containing a resin, a colorant, and an organic solvent is dispersed in an aqueous dispersion medium, and the acid value of the resin is 15 KOH mg/g or more and 100 KOH mg/g or less (see, for example, Patent Document 1). 2) A dispersion of colored resin particles comprising colored resin particles, a basic dispersant, and a non-aqueous solvent, wherein the colored resin particles comprise a colorant and a (meth)acrylic resin, and the (meth)acrylic resin comprises a unit A having a carboxyl group, a unit B having a phosphate group and/or a phosphate ester group, and a unit C having an aromatic ring; an inkjet ink comprising this dispersion of colored resin particles (see, for example, Patent Document 2). 3) A colored resin particle dispersion containing colored resin particles and water, wherein the colored resin particles comprise at least one dye selected from the group consisting of oil-soluble dyes, disperse dyes, and vat dyes, and a water-insoluble chain polymer, the water-insoluble chain polymer having a structure represented by a specific formula, a cyclic structure, and hydrophilic groups. Known examples include colored resin particle dispersions and inks for inkjet use containing this colored resin particle dispersion (see, for example, Patent Document 3). However, while the inkjet-compatible colored resin particle dispersions and inkjet-compatible aqueous ink compositions described in Patent Documents 1 to 3 exhibit better color tones and color density than conventional materials, resulting in good color development, achieving a high level of balance between water resistance, light resistance, long-term stability, and color development remains difficult, and the results have not been satisfactory. Japanese Patent Publication No. 2013-91718 (Claims, Examples, etc.)Japanese Patent Publication No. 2018-53069 (Claims, Examples, etc.)Japanese Patent Publication No. 2014-132061 (Claims, Examples, etc.) Embodiments of the present invention will be described in detail below. However, it should be noted that the technical scope of the present invention is not limited to each of the embodiments described below, but extends to the invention described in the claims and its equivalents. The inkjet-compatible colored resin particle dispersion of the present invention is characterized in that colored resin particles, each composed of at least a (meth)acrylic acid ester monomer represented by the following general formula (X) and at least one dye selected from the following group A, are dispersed in water. [In the above formula (X), A is a hydrogen atom (H) or a methyl group ( CH3 ), and R represents a substituent having a hydrogen atom (H), an alkyl group having 1 to 22 carbon atoms, or a polyalkylene glycol chain having 2 to 18 carbon atoms. The substituent having an alkyl group or a polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, an alkoxy group having 1 to 18 carbon atoms, a perfluoroalkyl group having 1 to 18 carbon atoms, or a trialkoxysilyl group as a substituent.] Group A: Basic dyes, oil-soluble dyes, acid dyes, and salt-forming dyes which are salt-forming products of basic dyes. The (meth)acrylic acid ester monomer represented by the general formula (I) used in the present invention is chosen because it can produce stable particles with consistent concentrations of the above-mentioned dyes of group A that can be encapsulated, does not adversely affect other components, and has a long-lasting effect. In the above general formula (I), R represents a hydrogen atom (H), a C1-C22 alkyl group, or a substituent having a polyalkylene glycol chain with 2-C18 carbon atoms. The substituent having an alkyl group or polyalkylene glycol chain may have a phenyl group, a benzyl group, an epoxy group, a hydroxyl group, a dialkylamino group, a C1-C18 alkoxy group, a C1-C18 perfluoroalkyl group, or a trialkox