Magenta toner for electrostatic charge image development

Patent metadata

Field	Value
Publication number	US-10146147-B2
Application number	US-201815934472-A
Country	US
Kind code	B2
Filing date	Mar 23, 2018
Priority date	Mar 31, 2017
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

To provide a magenta toner for electrostatic charge image development including a crystalline polyester resin and an amorphous resin as a binder resin, which is a means for improving low temperature fixability, scattering properties, GI value, saturation, and light fastness.
A magenta toner for electrostatic charge image development including an amorphous resin and a crystalline polyester resin as a binder resin, wherein predetermined quinacridone-based pigment, metal element-containing monoazo pigment, and naphthol AS-based pigment are included as a coloring agent, and the combined content of the quinacridone-based pigment and the metal element-containing monoazo pigment is 50-90% by mass of the total coloring agent.

First claim

What is claimed is:

1. A magenta toner for electrostatic charge image development comprising an amorphous resin and a crystalline polyester resin as a binder resin, wherein a quinacridone-based pigment represented by the following General Formula (1), a metal element-containing monoazo pigment represented by the following General Formula (2) or (2′), and a naphthol AS-based pigment represented by the following General Formula (3) are comprised as a coloring agent, and a combined content of the quinacridone-based pigment and the metal element-containing monoazo pigment is 50-90% by mass of the total coloring agent:

wherein X and Z are independently of each other a halogen atom, or an optionally substituted alkyl group or alkoxy group; and n1 and n2 are an integer of 0-4, respectively;

wherein R and R′ denote a hydrogen atom, a halogen atom, or an optionally substituted alkyl group or alkoxy group; R″ denotes a halogen atom, or an optionally substituted alkyl group or alkoxy group; n3 is an integer of 0-4; X is a hydrogen atom or a carboxylic acid anion; M is a monovalent or divalent metal ion; and n is a number determined by a valence number of X and M so that the metal element-containing monoazo pigment is electrically neutral;

wherein R′ is an optionally substituted alkyl group or alkoxy group; n4 is an integer of 0-4; and Ar is a hydrogen atom, an optionally substituted aryl group, or the following:

2. The magenta toner for electrostatic charge image development of claim 1 , wherein a mass ratio of the quinacridone-based pigment and the metal element-containing monoazo pigment (quinacridone-based pigment: metal element-containing monoazo pigment) is 8:2 to 4:6.

3. The magenta toner for electrostatic charge image development of claim 1 , wherein the metal element-containing monoazo pigment includes strontium, sodium or calcium as the metal element.

4. The magenta toner for electrostatic charge image development of claim 1 , wherein the metal element-containing monoazo pigment includes a rosin compound.

5. The magenta toner for electrostatic charge image development of claim 1 , further comprising a release agent, wherein a total content of the coloring agent is 5-10% by mass, based on total 100% by mass of the binder resin and the release agent.

6. The magenta toner for electrostatic charge image development of claim 1 , wherein the binder resin has a domain matrix structure in which the amorphous resin containing at least a styrene acrylic resin is a matrix, and the crystalline polyester resin is a domain.

7. The magenta toner for electrostatic charge image development of claim 1 , further comprising a release agent, wherein the crystalline polyester resin is comprised at 5-30% by mass, based on total 100% by mass of the binder resin and the release agent.

8. The magenta toner for electrostatic charge image development of claim 1 , wherein the crystalline polyester resin is a hybrid crystalline polyester resin formed by chemically bonding a crystalline polyester polymerization segment and a vinyl polymerization segment.

9. The magenta toner for electrostatic charge image development of claim 1 , wherein the crystalline polyester resin has an acid value (AV value) of 15-30 mgKOH/g.

10. The magenta toner for electrostatic charge image development of claim 1 , wherein the amorphous resin contains an amorphous polyester resin.

Assignees

• Konica Minolta Inc

Inventors

• Kayamori Takanari
• Matsubara Masaharu
• Tonegawa Naoya
• Izawa Kouji
• Iioka Atsushi

Classifications

• G03G9/091 Primary

  Azo dyes · CPC title

• G03G9/08755 Primary

  Polyesters · CPC title

• G03G9/092

  Quinacridones · CPC title

• G03G9/0924 Primary

  Dyes characterised by specific substituents · CPC title

• C09B67/0051

  mixture of two or more monoazo dyes · CPC title