Method for producing colored resin particle dispersion liquid, colored resin particle dispersion liquid, and electrophotographic liquid developer

Abstract

A method for producing a colored resin particle dispersion liquid comprises: polycondensing a polyester-forming monomer in a nonaqueous solvent to produce an unsaturated polyester; graft-polymerizing an ethylenic unsaturated monomer to the unsaturated polyester in a nonaqueous solvent to produce a modified polyester resin; and dispersing a colorant and the modified polyester resin to produce a colored resin particle dispersion liquid, the polycondensing and the graft-polymerizing being carried out at a temperature of 150° C. or less.

Description

Claims

1. A method for producing a colored resin particle dispersion liquid comprising: polycondensing a polyester-forming monomer in a nonaqueous solvent to produce an unsaturated polyester;graft-polymerizing an ethylenic unsaturated monomer to the unsaturated polyester in a nonaqueous solvent to produce a modified polyester resin; anddispersing a colorant and the modified polyester resin to produce a colored resin particle dispersion liquid, the polycondensing and the graft-polymerizing being carried out at a temperature of about 150° C. or less.

2. The method for producing a colored resin particle dispersion liquid as claimed in claim 1, wherein the modified polyester resin is produced in the presence of the ethylenic unsaturated monomer and the colorant.

3. The method for producing a colored resin particle dispersion liquid aid claimed in claim 1, wherein the colored resin particle dispersion liquid has a number average particle size of from about 0.05 to 1.0 μm.

4. The method for producing a colored resin particle dispersion liquid as claimed in claim 1, wherein the polyester-forming monomer provides a number of an aromatic ring and/or an alicyclic ring per repeating unit of 2 or more in the unsaturated polyester, andthe polyester-forming monomer is polycondensed with a polycondensation catalyst in the nonaqueous solvent.

5. The method for producing a colored resin particle dispersion liquid as claimed in claim 1, wherein the ethylenic unsaturated monomer comprises at least one selected from the group consisting of a monomer having an aromatic ring, a monomer having an acidic group and a monomer having a basic group.

6. The method for producing a colored resin particle dispersion liquid as claimed in claim 1, wherein the colorant is selected from the group consisting of a pigment, a dye and an oil soluble dye.

7. The method for producing a colored resin particle dispersion liquid claimed in claim 1, wherein the polyester-forming monomer is polycondensed with a catalyst comprising at least one of a Brønsted acid and a surfactant type Brønsted acid.

8. The method for producing a colored resin particle dispersion liquid as claimed in claim 1, wherein the polyester-forming monomer comprises an unsaturated polycarboxylic acid in the amount of from about 0.1 to 5% by weight.

9. The method for producing a colored resin particle dispersion liquid as claimed in claim 8, wherein the unsaturated polycarboxylic acid is an ethylenic unsaturated polycarboxylic acid.

10. A colored resin particle dispersion liquid produced by the method as claimed in claim 1, wherein the modified polyester resin has a weight average molecular weight of from about 1,500 to 40,000.

11. The colored resin particle dispersion liquid as claimed in claim 10, wherein the modified polyester resin has a melt viscosity at 100° C. of from about 103 to 106 poise.

12. The colored resin particle dispersion liquid as claimed in claim 10, wherein the modified polyester resin has an acid value of from about 10 to 200 mgKOH/g.

13. The colored resin particle dispersion liquid as claimed in claim 10, wherein the modified polyester resin has an amine value of from about 10 to 200 mgKOH/g.

14. An electrophotographic liquid developer comprising the colored resin particle dispersion liquid as claimed in claim 10.

15. An ink composition comprising the colored resin particle dispersion liquid as claimed in claim 10.