IMAGE FORMING APPARATUS, AND TONER AND DEVELOPER USED THEREIN

Abstract

An image forming apparatus producing images at a speed of from 500 to 1,700 mm/sec, including an image bearer; a charger; an irradiator; an image developer developing an electrostatic latent image with a developer including a toner including a binder resin and a colorant; a transferer; a cleaner; and a fixer, wherein the binder resin includes a crystalline polyester resin and an amorphous resin, wherein a peak ratio (W/R) of a specific peak height (W) of the crystalline polyester resin to a specific peak height (R) of the amorphous resin is from 0.050 to 0.555, and a toner transfer rate T (%) determined by the following formula (1) is from 75 to 100%:

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 in which like reference characters designate like corresponding parts throughout and wherein:

FIG. 1 is a schematic cross-sectional view illustrating an embodiment of the image forming apparatus of the present invention;

FIG. 2 is a diagram showing a specific spectrum of the crystal state of a crystalline polyester resin;

FIG. 3 is a diagram showing a specific spectrum of the crystal state of an amorphous polyester resin;

FIG. 4 is a diagram showing a specific spectrum of the crystal state of an amorphous styrene-acrylic resin;

FIG. 5 is a diagram showing a X-ray diffraction spectrum of a crystalline polyester resin; and

FIG. 6 is a diagram showing a X-ray diffraction spectrum of the toner of the present invention.

Claims

1. An image forming apparatus, comprising: an image bearer;a charger configured to charge the image bearer;an irradiator configured to irradiate the image bearer to form an electrostatic latent image on the image bearer;an image developer configured to develop the electrostatic latent image with a developer comprising a toner to form a toner image on the image bearer;a transferer configured to transfer the toner image onto a recording medium;a cleaner configured to remove the toner remaining on the image bearer after transfer; anda fixer configured to fix the toner image on the recording medium,wherein the image forming apparatus produces images at a speed of from 500 to 1,700 mm/sec and the toner comprises a binder resin and a colorant,wherein the binder resin comprises a crystalline polyester resin and an amorphous resin, wherein a peak ratio (W/R) of a specific peak height (W) of the crystalline polyester resin to a specific peak height (R) of the amorphous resin, when respective spectra are observed and measured by a total reflection method using a Fourier transform infrared spectroanalyzer, is from 0.050 to 0.555, andwherein a toner transfer rate T (%) determined by the following formula (1) is from 75 to 100%: T(%)=(V−A)×100/V  (1) wherein V represents a toner volume (mg/cm2) of the toner image on the image bearer; and A represents a toner volume (mg/cm2) thereof remaining on the image bearer after transfer.

2. The image forming apparatus of claim 1, wherein the developer is a two-component developer including the toner in an amount of 4% by weight and a magnetic particulate carrier, and wherein the toner has a variation rate P (%) of charge quantity determined by the following formula (2): P(%)=(M−H)×100/(H+ M)/2  (2)

3. The image forming apparatus of claim 1, wherein the amorphous resin is a polyester resin formed in the presence of a titanium-containing catalyst (a) having the following formula (I) or (II): Ti(—X)m(—OH)n  (I)O═Ti(—X)p(—OR)q  (II)

4. The image forming apparatus of claim 3, wherein the titanium-containing catalyst (a) is a catalyst of formula (I) selected from the group consisting of titaniumdihydroxybis(triethanolaminate), titaniumtrihydroxytriethanolaminate, titaniumdihydroxybis(diethanolaminate), titaniumdihydroxybis(monoethanolaminate), titaniumdihydroxybis(monopropanolaminate), titaniumdihydroxybis(N-methyldiethanolaminate), titaniumdihydroxybis(N-butyldiethanolaminate), a reaction product between tetrahydroxytitanium and N,N,N′,N′-tetrahydroxyethylethylenediamine, intramolecular polycondensates thereof and intermolecular polycondensates thereof.

5. The image forming apparatus of claim 3, wherein the titanium-containing catalyst (a) is a catalyst of formula (II) selected from the group consisting of titanylbis(triethanolaminate), titanylbis(diethanolaminate), titanylbis(monoethanolaminate), titanylhydroxyethanolaminate, titanylhydroxytriethanolaminate, titanylethoxytriethanolaminate, titanylisopropoxytriethanolaminate, intramolecular polycondensates thereof and intermolecular polycondensates thereof.

6. The image forming apparatus of claim 1, wherein the crystalline polyester resin has an acid value of from 20 to 45 mg KOH/g.

7. The image forming apparatus of claim 1, wherein the crystalline polyester resin has a hydroxyl value of from 5 to 50 mg KOH/g.

8. The image forming apparatus of claim 1, wherein the toner further comprises a wax having a melting point of from 70 to 150° C. as a release agent.

9. The image forming apparatus of claim 1, wherein the peak ratio (W/R) is from 0.08 to 0.450.

10. The image forming apparatus of claim 8, wherein the wax is a member selected from the group consisting of carnauba waxes, polyethylene waxes and synthetic ester waxes.

11. A container containing a toner or a developer, wherein the toner or the developer is used in the image forming apparatus of claim 1.

12. A process cartridge comprising an image developer and at least one of an image bearer, a charger and a cleaner, which is detachable from an image forming apparatus, wherein the image developer develops an electrostatic latent image with the developer according to claim 11.