Toner, image forming apparatus, image forming method, process cartridge, and two-component developer

Patent metadata

Field	Value
Publication number	US-9494886-B2
Application number	US-201314421016-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Sep 3, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

To provide a toner, which contains: a colorant; a resin; and a releasing agent, wherein a spin-spin relaxation time (T2s) originated from a soft component is 0.10 msec to 0.50 msec, where the soft component is obtained with a hard component from an echo signal of the toner by a solid-echo technique of pulsed NMR, and a proportion of a proton intensity of the soft component is 50.0% or lower.

First claim

The invention claimed is:

1. A toner comprising toner particles, the toner particles having a core-shell structure and comprising:
a colorant;
a crystalline polyester resin that comprises a urethane bond, or a urea bond, or a combination thereof; and
a releasing agent,
wherein a spin-spin relaxation time (T2s) originated from a soft component is 0.10 msec to 0.50 msec, where the soft component is obtained with a hard component from an echo signal of the toner particles by a solid-echo technique of pulsed NMR, and a proportion of a proton intensity of the soft component is 50.0% or lower.

2. The toner according to claim 1 , wherein the spin-spin relaxation time (T2s) originated from the soft component is 0.20 msec to 0.50 msec.

3. The toner according to claim 1 , wherein the spin-spin relaxation time (T2s) originated from the soft component is 0.30 msec to 0.50 msec.

4. The toner according to claim 1 , wherein the toner satisfies the following relational expressions:
T 1− T 2≦30.0° C., and, T 2≧30.0° C.

where T1 is a maximum endothermic peak obtained from first heating from 0° C. to 100° C. as measured by DSC of the toner, and T2 is a maximum exothermic peak obtained from cooling.

5. The toner according to claim 1 , wherein a maximum endothermic peak temperature obtained from second heating from 0° C. to 100° C. as measured by DSC of the toner falls in a range of 50° C. to 70° C., and an amount of heat of melting in the second heating is 30.0 Jig to 75.0 J/g.

6. The toner according to claim 1 , wherein 5% or more of a tetrahydrofuran (THF) soluble component of the toner has a molecular weight of 100,000 or greater as measured by gel permeation chromatography, and the THF soluble component has a weight average molecular weight (Mw) of 20,000 to 70,000.

7. The toner according to claim 1 , wherein the crystalline polyester resin comprises a urethane bond.

8. The toner according to claim 7 , wherein the crystalline polyester resin comprises a urea bond.

9. An image forming apparatus/toner combination, comprising:
a latent electrostatic image bearing member;
a latent electrostatic image forming unit configured to form a latent electrostatic image on the latent electrostatic image bearing member;
a developing unit comprising the toner according to claim 1 and configured to develop the latent electrostatic image with the toner, to thereby form a visible image;
a transferring unit configured to transfer the visible image onto a recording medium;
a fixing unit configured to fix the visible image on the recording medium with heat and pressure of a fixing member,
wherein the image forming apparatus employs a tandem developing system where at least four image forming units each using a different color for developing are tandemly provided, and a system speed thereof is 200 mm/sec to 3,000 mm/sec, and
wherein contact pressure of the pressing fixing member is 10 N/cm 2 to 3,000 N/cm 2 , and a fixing nip time is 30 msec to 400 msec.

10. An image forming method, comprising:
forming a latent electrostatic image on a latent electrostatic image bearing member;
developing the latent electrostatic image with a toner to form a visible image;
transferring the visible image onto a recording medium; and
fixing the visible image on the recording medium with heat and pressure of a fixing member,
wherein the image forming method employs a tandem developing system where at least four image forming units each using a different color for developing are tandemly provided, and a system speed thereof is 200 mm/sec to 3,000 mm/sec,
wherein contact pressure of the pressing fixing member is 10 N/cm 2 to 3,000 N/cm 2 , and a fixing nip time is 30 msec to 400 msec, and
wherein the toner is the toner according to claim 1 .

11. A process cartridge/toner combination, comprising:
a latent electrostatic image bearing member configured to bear a latent electrostatic image thereon; and
a developing unit comprising the toner according to claim 1 and configured to develop the latent electrostatic image on the latent electrostatic image bearing member with a toner, to thereby form a visible image.

12. A two-component developer, comprising:
the toner according to claim 1 ; and
a carrier.

Assignees

• Kumai Mio
• Sugiura Hideki
• Ricoh Co Ltd

Inventors

• Kumai Mio
• Sugiura Hideki

Classifications

• G03G9/0825

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title

• G03G2215/0607

  two-component · CPC title

• G03G9/08724 Primary

  Polyvinylesters · CPC title

• G03G9/08797

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G9/0821 Primary

  characterised by physical parameters (magnetic parameters G03G9/083) · CPC title