RESIN-FILLED CARRIER FOR ELECTROPHOTOGRAPHIC DEVELOPER, AND ELECTROPHOTOGRAPHIC DEVELOPER USING THE RESIN-FILLED CARRIER

• US 20090239173A1
• Filed: 03/05/2009
• Published: 09/24/2009
• Est. Priority Date: 03/18/2008
• Status: Abandoned Application

• Current Assignee: Powdertech Co., Ltd.
• Original Assignee: Powdertech Co., Ltd.
• Inventors: KOBAYASHI, Hiromichi, SUGIURA, Takao
• Application Number:
  US12/398,322
• Publication Number:
  US 20090239173A1
• Time in Patent Office: Days
• US Class Current: 430/111.310
• CPC Class Codes: G03G 9/1131 Coating methods; Structure of coatings
• CPC Class Codes: G03G 9/1136 containing silicon atoms
• CPC Class Codes: G03G 9/1137 being crosslinked
• CPC Class Codes: G03G 9/1138 Non-macromolecular organic components of coatings
• CPC Class Codes: G03G 9/1139 Inorganic components of coatings

Abstract

A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.04 to 0.16 mL/g and a peak pore size of 0.9 to 2.0 μm, and wherein microparticles are included in the resin to be filled, and an electrophotographic developer using this resin-filled carrier.

Claims

1. A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.04 to 0.16 mL/g and a peak pore size of 0.9 to 2.0 μ

m, and wherein microparticles are included in the resin to be filled.

2. The resin-filled carrier for an electrophotographic developer according to claim 1, wherein in the pore size distribution of the porous ferrite core material, pore size unevenness dv represented by the following formula (1) is 1.5 or less,

dv=|d₈₄−

d₁₆|/2  

 

(1)

wherein d₁₆ is a pore size calculated from the applied pressure on mercury when the mercury pressure penetration reaches 16%, where the total pressure penetration in the high pressure region is 100%; and

d₈₄ is a pore size calculated from the applied pressure on mercury when the mercury pressure penetration reaches 84%, in which the total pressure penetration in the high pressure region is 100%.

3. The resin-filled carrier for an electrophotographic developer according to claim 1, wherein the microparticles are a metal oxide, resin microparticles, or a mixture thereof.

4. The resin-filled carrier for an electrophotographic developer according to claim 3, wherein the metal oxide comprises at least one selected from the group consisting of Ti, Si, and Al.

5. The resin-filled carrier for an electrophotographic developer according to claim 3, wherein the resin microparticles are crosslinked resin microparticles.

6. The resin-filled carrier for an electrophotographic developer according to claim 1, wherein the resin is filled in the porous ferrite core material in an amount of 6 to 30 parts by weight based on 100 parts by weight of the porous ferrite core material.

7. The resin-filled carrier for an electrophotographic developer according to claim 1, having a volume average particle size of 20 to 60 μ

m, and a ratio of volume average particle size to number average particle size (volume average particle size/number average particle size) of 1.00 to 1.30.

8. The resin-filled carrier for an electrophotographic developer according to claim 1, having a saturated magnetization of 30 to 80 Am²/kg.

9. The resin-filled carrier for an electrophotographic developer according to claim 1, having a pyconometer density of 2.5 to 4.5 g/cm³.

10. The resin-filled carrier for an electrophotographic developer according to claim 1, having an apparent density of 1.0 to 2.5 g/cm³.

11. An electrophotographic developer comprising the resin-filled carrier according to claim 1 and a toner.

12. The electrophotographic developer according to claim 11, which is used as a supply developer.