Toner and image forming apparatus using the same

• US 6,730,449 B2
• Filed: 02/24/2003
• Issued: 05/04/2004
• Est. Priority Date: 12/06/2000
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Toyama, Hiroshi
• Primary Examiner(s): Chapman, Mark A.
• Application Number:
  US10/372,504
• Publication Number:
  US 20030170557A1
• Time in Patent Office: 435 Days
• Field of Search: 430/108.1, 430/111.4, 399/252
• US Class Current: 430/108.1
• CPC Class Codes: G03G 9/097 Plasticisers; Charge controlling agents

Abstract

A non-magnetic mono-component toner of the present invention comprises, at least, a plurality of mother particles and a plurality of CCA particles adhering to the mother particles. The non-magnetic mono-component toner satisfies a×d<2.5, wherein “a” is the inclination of an approximation straight line of the CCA particles adhering to the mother particles, obtained by approximating distribution of particle diameter of the CCA particles relative to the particle diameter of the mother particles by the least-square method, and “d” (μm) is the volume-based mean particle diameter of the toner. Therefore, the charge on one particle of the non-magnetic mono-component toner can be efficiently reduced, thereby allowing lower developing voltage and achieving reduction in developing hysteresis.

Claims

1. A toner comprising, at least, a plurality of mother particles and a plurality of additives which are contained in the mother particles,

said toner having a liberation ratio of liberated additives liberated from said mother particles which is set to be equal to or less than a specified value corresponding to the additives,

wherein a CCA and a pigment are used as said additives and the liberation ratio of the liberated CCA is set to be 1.0% or less.

2. A toner as claimed in claim 1, wherein the liberation ratio of the mother particles in which the CCA is not contained is set to be 3.0% or less.

3. A toner as claimed in claim 1, wherein the liberation ratio of the liberated pigment is set to be 0.6% or less.

4. A toner as claimed in claim 1, wherein the toner is a pulverized toner prepared by pulverization, and that at least one of a mold releasing agent and a pulverization assisting agent is used as one of said additives and the liberation ratio of the at least one of the mold releasing agent and the pulverization assisting agent liberated from the mother particles is set to be 0.4% or less.

5. A toner as claimed in claim 1, wherein the toner is a polymerized toner prepared by polymerization, and that at least one of an initiator and dispersant to be added for polymerization reaction is used as one of said additives and the liberation ratio of the at least one of the initiator and the dispersant from the mother particles is 0.3% or less.

6. An image forming apparatus comprising:

a latent image carrier on which an electrostatic latent image is formed; and

a developing device having a conductive developing roller for carrying a toner to develop the electrostatic latent image on said latent image carrier, and a toner regulating means for regulating the toner to be carried toward said latent image carrier and charging said toner,

wherein said toner includes at least a plurality of mother particles and a plurality of additives which are contained in the mother particles,

said toner having a liberation ratio of liberated additives liberated from said mother particles that is set to be equal to or less than a specified value corresponding to the additives, and

wherein a CCA and a pigment are used as said additives and the liberation ratio of the liberated CCA is set to be 1.0% or less.

7. An image forming apparatus as claimed in claim 6, wherein the liberation ratio of the mother particles in which the CCA is not contained is set to be 3.0% or less.

8. An image forming apparatus as claimed in claim 6, wherein the liberation ratio of the liberated pigment is set to be 0.6% or less.

9. An image forming apparatus as claimed in claim 6, wherein the toner is a pulverized toner prepared by pulverization, and that at least one of a mold releasing agent and a pulverization assisting agent is used as one of said additives and the liberation ratio of the at least one of the mold releasing agent and the pulverization assisting agent liberated from the mother particles is set to be 0.4% or less.

10. An image forming apparatus as claimed in claim 6, wherein the toner is a polymerized toner prepared by polymerization, and that at least one of an initiator and a dispersant to be added for polymerization reaction is used as one of said additives and the liberation ratio of the at least one of the initiator and the dispersant from the mother particles is 0.3% or less.

11. An image forming apparatus as claimed in claim 6, wherein the liberation ratio of liberated additives liberated from said mother particles is set to be equal to or less than a specified value corresponding to the additives, and

wherein the liberation ratio of the liberated pigment is set to be 0.6% or less.

12. A toner comprising, at least, a plurality of mother particles and a plurality of additives which are contained in the mother particles,

said toner having a liberation ratio of liberated additives liberated from said mother particles which is set to be equal to or less than a specified value corresponding to the additives,

wherein a pigment is used as one of said additives and the liberation ratio of the liberated pigment is set to be 0.6% or less.

13. A toner as claimed in claim 12, wherein the toner is a pulverized toner prepared by pulverization, and that at least one of a mold releasing agent and a pulverization assisting agent is used as one of said additives and the liberation ratio of the at least one of the mold releasing agent and the pulverization assisting agent liberated from the mother particles is set to be 0.4% or less.

14. A toner as claimed in claim 12, wherein the toner is a polymerized toner prepared by polymerization, and that at least one of an initiator and a dispersant to be added for polymerization reaction is used as one of said additives and the liberation ratio of the at least one of the initiator and the dispersant from the mother particles is 0.3% or less.