Toner for developing electrostatic image, developer for developing electrostatic image, and method for forming image

Abstract

A toner for developing an electrostatic image comprises: a binder resin; and a releasing agent, wherein the binder resin comprises a polycondensation resin obtained by polycondensing a polycondensation monomer in the presence of a polycondensation catalyst, the releasing agent comprises a condensation compound obtained by condensing a condensation monomer in the presence of a condensation catalyst, the toner contains a metallic element derived from the polycondensation catalyst and the condensation catalyst in an amount of from 0 to 10 ppm, and the toner contains a sulfur component in an amount of from 100 to 20,000 ppm.

Description

Claims

1. A toner for developing an electrostatic image, the toner comprising: a binder resin; anda releasing agent,wherein the binder resin comprises a polycondensation resin obtained by polycondensing a polycondensation monomer in the presence of a polycondensation catalyst,the releasing agent comprises a condensation compound obtained by condensing a condensation monomer in the presence of a condensation catalyst,the toner contains a metallic element derived from the polycondensation catalyst and the condensation catalyst in an amount of from 0 ppm to about 10 ppm, andthe toner contains a sulfur component in an amount of from about 100 ppm to about 20,000 ppm.

2. The toner for developing an electrostatic image according to claim 1, wherein the binder resin comprises the polycondensation resin in an amount of about 40% by weight or more.

3. The toner for developing an electrostatic image according to claim 1, wherein the binder resin comprises a noncrystalline polyester in an amount of from about 1% to about 90% by weight.

4. The toner for developing an electrostatic image according to claim 3, wherein the noncrystalline polyester has a glass transition temperature Tg of from about 40° C. to about 100° C.

5. The toner for developing an electrostatic image according to claim 3, wherein the noncrystalline polyester has a weight average molecular weight of from about 1,000 to about 60,000 measured by a gel permeation chromatography (GPC) molecular weight measuring method of a component soluble in tetrahydrofuran (THF).

6. The toner for developing an electrostatic image according to claim 1, wherein the binder resin comprises a crystalline polyester.

7. The toner for developing an electrostatic image according to claim 6, wherein the crystalline polyester has a crystal melting temperature Tm of from about 50° C. to about 120° C.

8. The toner for developing an electrostatic image according to claim 6, wherein the crystalline polyester has a weight average molecular weight of from about 1,000 to about 60,000 measured by a gel permeation chromatography (GPC) molecular weight measuring method of a component soluble in tetrahydrofuran (THF).

9. The toner for developing an electrostatic image according to claim 1, wherein the metallic element derived from the polycondensation catalyst and the condensation catalyst is selected from the group of consisting of tin, titanium, antimony, beryllium, strontium, germanium and a rare earth metal.

10. The toner for developing an electrostatic image according to claim 1, wherein the condensation compound comprises the metallic element in an amount of from about 0 ppm to about 10 ppm.

11. The toner for developing an electrostatic image according to claim 1, wherein the releasing agent is a crystalline ester.

12. The toner for developing an electrostatic image according to claim 11, wherein the crystalline ester is represented by formula (1): R1—(OCO—R2)n   (1)wherein R1 and R2 each represents a hydrocarbon group, which may have a substituent, and n represents an integer of 1 or more.

13. The toner for developing an electrostatic image according to claim 12, wherein the hydrocarbon group R1 has from 1 to 40 carbon atoms.

14. The toner for developing an electrostatic image according to claim 11, wherein a carboxylic acid constituting the crystalline ester is selected from those having from 14 to 30 carbon atoms.

15. The toner for developing an electrostatic image according to claim 1, which has a volume average particle size distribution index GSDv of about 1.30 or less.

16. The toner for developing an electrostatic image according to claim 1, which has a shape factor SF1 of from about 100 to about 140.

17. A method for producing the toner for developing an electrostatic image as claimed in claim 1, the method comprising: aggregating binder resin particles comprising a polycondensation resin and releasing agent particles comprising a condensation compound in an aqueous medium; andfusing and integrating the aggregated particles by heating.

18. A developer for developing an electrostatic image comprising: a toner for developing an electrostatic image as claimed in claim 1; anda carrier.

19. A method for forming an image comprising: forming an electrostatic latent image on a surface of a latent image carrying member;developing the electrostatic latent image formed on the surface of the latent image carrying member with a developer comprising a toner to form a toner image;transferring the toner image formed on the surface of the latent image carrying member to a surface of a transfer material; andfixing the toner image transferred to the surface of the transfer material by heating,wherein the toner is a toner for developing an electrostatic image as claimed in claim 1.

20. A method for forming an image comprising: forming an electrostatic latent image on a surface of a latent image carrying member;developing the electrostatic latent image formed on the surface of the latent image carrying member with a developer comprising a toner to form a toner image;transferring the toner image formed on the surface of the latent image carrying member to a surface of a transfer material; andfixing the toner image transferred to the surface of the transfer material by heating,wherein the developer is a developer for developing an electrostatic image as claimed in claim 18.