Coloring particles
AssigneeCanon Kabushiki Kaisha
InventorsShinnosuke Koji, Kazumichi Nakahama, Shoji Koike
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Abstract
The present invention provides coloring particles containing a dye and a water-insoluble low-molecular-weight dispersant, wherein the average particle size of the coloring particles is 10 nm or more and 80 nm or less; the solubility parameter of the dye in water with a pH of 6.0 to 10.0 is 9.20 or more, the solubility parameter being represented by formula (1); and the content of the dye and the content of the water-insoluble low-molecular-weight dispersant satisfy a relationship of formula (2).
Claims6
Coloring particles comprising:
- a dye and a water-insoluble low-molecular-weight dispersant,
- wherein the average particle size of the coloring particles is 10 nm or more and 80 nm or less;
- the dispersant is selected from the group consisting of lauric acid, oleic acid, linoleic acid, toluic acid, cinnamic acid, and palmitic acid;
- the solubility parameter of the dye in water with a pH of 6.0 to 10.0 is 9.20 or more, the solubility parameter being represented by formula (1) below;
- and the content of the dye and the content of the water-insoluble low-molecular-weight dispersant satisfy a relationship of formula (2) below on a mass basis
- Solubility parameter=log(1/(aqueous solubility of dye <mol/L>)) Formula (1)
- 3/2≦(Content of dye in coloring particles)/(Content of water-insoluble low-molecular-weight dispersant in coloring particles). Formula (2)
A method for producing coloring particles containing a dye and a water-insoluble low-molecular-weight dispersant, the method comprising:
- an emulsifying step of emulsifying a first liquid obtained by mixing a dye, a water-insoluble low-molecular-weight dispersant, and an oil-based solvent and a second liquid containing a water-soluble dispersant and a water-based solvent to obtain an emulsion having dispersoids that contain the first liquid and are dispersed using the water-soluble dispersant;
- a dispersant replacing step of replacing the water-soluble dispersant that is dispersing the dispersoids with the water-insoluble low-molecular-weight dispersant by desorbing the water-soluble dispersant from surfaces of the dispersoids;
- and
- a removing step of removing the oil-based solvent from the dispersoids,
- wherein the dispersant is selected from the group consisting of lauric acid, oleic acid, linoleic acid, toluic acid, cinnamic acid, and palmitic acid, the solubility parameter of the dye in water with a pH of 6.0 to 10.0 is 9.20 or more, the solubility parameter being represented by formula (1) below, and the content of the dye and the content of the water-insoluble low-molecular-weight dispersant satisfy a relationship of formula (2) below on a mass basis
- Solubility parameter=log(1/(aqueous solubility of dye <mol/L>)) Formula (1)
- 3/2≦(Content of dye in coloring particles)/(Content of water-insoluble low-molecular-weight dispersant in coloring particles). Formula (2)
Dependencies are inferred from the claim text.