TONER, DEVELOPING DEVICE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD USING THE TONER

Abstract

A toner is provided including a colorant; a binder resin (A) which is a polyester resin having no tetrahydrofuran insoluble component, and having a molecular weight distribution such that components having a molecular weight of not greater than 500 are included in an amount of not greater than 4% by weight and a peak is present in a molecular weight range of from 3,000 to 9,000 when measured by gel permeation chromatography (GPC); and a binder resin (B) which is a polyester resin having no tetrahydrofuran insoluble component, and including units of a polycarboxylic acid and a diol having the specific formula; wherein at least one of the binder resins (A) and (B) is prepared in the presence of the specific titanium-containing catalyst, and wherein a weight ratio ((A)/(B)) of the binder resin (A) to the binder resin (B) is from 60/40 to 85/15.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the present invention will become apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic view illustrating an embodiment of the developing device of the present invention;

FIGS. 2A to 2C are schematic views for explaining how the toner in the toner cartridge is agitated and transported by a rotation member; and

FIG. 3 is a schematic view illustrating an embodiment of the image forming apparatus of the present invention.

Claims

1. A toner, comprising: a colorant;a binder resin (A) which is a polyester resin having no tetrahydrofuran insoluble component, and having a molecular weight distribution such that components having a molecular weight of not greater than 500 are included in an amount of not greater than 4% by weight and a peak is present in a molecular weight range of from 3,000 to 9,000 when measured by gel permeation chromatography (GPC); anda binder resin (B) which is a polyester resin having no tetrahydrofuran insoluble component, and comprising units of a polycarboxylic acid and a diol having the following formula (1):

2. The toner according to claim 1, wherein the diol is a methacrylate monomer adduct of a bisphenol A.

3. The toner according to claim 1, wherein a main peak molecular weight of the binder resin (B) when measured by GPC is larger than that of the binder resin (A).

4. The toner according to claim 3, wherein the main peak molecular weight of the binder resin (B) is from 1.1 to 2.0 times that of the binder resin (A).

5. The toner according to claim 1, further comprising a charge controlling agent.

6. The toner according to claim 5, wherein the charge controlling agent is a negative charge controlling resin comprising constitutional units of a monomer having a sulfonate group, a phenyl maleimide or phenyl itaconimide monomer substituted with a chlorine atom or a nitro group, at least one member selected from the group consisting of an acrylate monomer and a methacrylate monomer, and an aromatic vinyl monomer.

7. The toner according to claim 6, wherein the negative charge controlling resin comprises constitutional units of the monomer having a sulfonate group in an amount of from 1 to 30% by weight, the phenyl maleimide or phenyl itaconimide monomer substituted with a chlorine atom or a nitro group in an amount of from 1 to 80% by weight, at least one member selected from the group consisting of the acrylate monomer and the methacrylate monomer in an amount of from 10 to 80% by weight, and the aromatic vinyl monomer in an amount of from 0 to 30% by weight.

8. The toner according to claim 1, further comprising an external additive.

9. The toner according to claim 8, wherein the external additive comprises 2 or more external additives, each of which has a different particle diameter.

10. The toner according to claim 8, wherein the external additive comprises an external additive having a BET specific surface area of from 30 to 80 m2/g.

11. The toner according to claim 9, wherein the external additive comprises an external additive having a BET specific surface area of from 30 to 80 m2/g and another external additive having a BET specific surface area of from 100 to 250 m2/g.

12. A developer, comprising the toner according to claim 1 and a carrier.

13. A developing device, comprising: a developing unit configured to supply a toner to an image forming part;a toner cartridge configured to supply the toner to the developing unit, comprising a first rotation member configured to agitate and transport the toner and a projection arranged on an inner wall thereof;a hopper configured to temporary trap the toner supplied from the toner cartridge to the developing unit, comprising a second rotation member configured to agitate and transport the toner;at least one opening configured to pass the toner between the toner cartridge and the developing unit; andat least one control valve configured to open and shut the at least one opening,wherein the control valve accelerates supplying the toner from the toner cartridge to the hopper by contacting the second rotation member, and the projection accelerates discharging the toner from the hopper to the toner cartridge by contacting the first rotation member, andwherein the toner is the toner according to claim 1.

14. An image forming apparatus, comprising: an image bearing member configured to bear an electrostatic latent image thereon;an electrostatic latent image forming device configured to form the electrostatic latent image on the image bearing member;a developing device configured to develop the electrostatic latent image with a toner to form a toner image;a transfer device configured to transfer the toner image onto a transfer member; anda fixing device configured to fix the toner image to the transfer member,wherein the developing device comprises: a developing unit configured to supply the toner to an image forming part;a toner cartridge configured to supply the toner to the developing unit, comprising a first rotation member configured to agitate and transport the toner and a projection arranged on an inner wall thereof;a hopper configured to temporary trap the toner supplied from the toner cartridge to the developing unit, comprising a second rotation member configured to agitate and transport the toner;at least one opening configured to pass the toner between the toner cartridge and the developing unit; andat least one control valve configured to open and shut the at least one opening,wherein the control valve accelerates supplying the toner from the toner cartridge to the hopper by contacting the second rotation member, and the projection accelerates discharging the toner from the hopper to the toner cartridge by contacting the first rotation member, andwherein the toner is the toner according to claim 1.

15. An image forming method, comprising: forming an electrostatic latent image on an image bearing member;developing the electrostatic latent image with a toner to form a toner image;transferring the toner image onto a transfer member;fixing the toner image to the transfer member,wherein the developing step comprises: supplying the toner to the electrostatic latent image formed on the image bearing member by rotating a developing roller comprising a developing blade configured to control a thickness of a toner layer so as to contact or come close to the image bearing member, andwherein the toner is the toner according to claim 1.