Developing apparatus, developing method, image-forming apparatus, and image-forming method

Patent metadata

Field	Value
Publication number	US-9354545-B2
Application number	US-201414568058-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 26, 2013
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Provided is a developing apparatus, including: a toner for developing an electrostatic latent image; a toner carrier for carrying the toner; and a regulating member for regulating a layer thickness of the toner carried by the toner carrier, in which: the toner includes a toner containing toner particles each containing a binder resin and a magnetic material, and inorganic fine particles present on surfaces of the toner particles; the toner has a dielectric loss factor (∈″) at a frequency of 100 kHz and a temperature of 30° C. of 0.03 pF/m or more and 0.30 pF/m or less; the toner carrier includes a substrate, an elastic layer, and a surface layer containing a urethane resin; and the urethane resin has a partial structure derived from a reaction between a compound represented by the structural formula (1) and a polyisocyanate.

First claim

What is claimed is:

1. A developing apparatus for developing an electrostatic latent image formed on a surface of an electrostatic latent image bearing member to form a toner image on the surface of the electrostatic latent image bearing member, the developing apparatus comprising:
a toner for developing the electrostatic latent image;
a toner carrier for carrying the toner; and
a regulating member for regulating a layer thickness of the toner carried by the toner carrier,
wherein:
the toner comprises a toner containing
toner particles each containing a binder resin and a magnetic material, and
inorganic fine particles present on surfaces of the toner particles;

the toner has a dielectric loss factor (∈″) at a frequency of 100 kHz and a temperature of 30° C. of 0.03 pF/m or more and 0.30 pF/m or less;
the toner carrier includes
a substrate,
an elastic layer, and
a surface layer containing a urethane resin; and

the urethane resin has a partial structure derived from a reaction between
a compound represented by the following structural formula (1) and
a polyisocyanate:

in the structural formula (1):
n represents an integer of 1 or more and 4 or less;
R 3 's each independently represent a group selected from the group consisting of the following (a) to (c):

(a) a hydroxyalkyl group having 2 or more and 8 or less carbon atoms,
(b) an aminoalkyl group having 2 or more and 8 or less carbon atoms, and
(c) a group represented by the following structural formula (2); and
R 4 represents an alkylene group having 2 or more and 4 or less carbon atoms:

in the structural formula (2):
m in 2 or 3; and
R 5 represents an alkylene group having 2 or more and 5 or less carbon atoms.

2. A developing apparatus according to claim 1 , wherein the dielectric loss factor (∈″) of the toner at a frequency of 100 kHz and a temperature of 30° C. is 0.05 pF/m or more and 0.25 pF/m or less.

3. A developing apparatus according to claim 1 , wherein the toner has a dielectric constant (∈′) of 25 or more and 35 or less.

4. A developing apparatus according to claim 1 , wherein the toner has a moisture adsorption amount at a temperature of 30° C. and a humidity of 90% of 2.5 mg/g or less.

5. A developing apparatus according to claim 1 , wherein the magnetic material comprises a treated magnetic material obtained by treating a surface of magnetic iron oxide with a silane compound.

6. A developing apparatus according to claim 5 , wherein:
the magnetic iron oxide has a silicon atom on the surface; and
an amount of silicon to be eluted when the magnetic iron oxide is dissolved until a dissolution ratio of an iron atom becomes 5 mass % is 0.05 mass % or more and 0.50 mass % or less with reference to the magnetic iron oxide.

7. A developing apparatus according to claim 5 , wherein an amount of remaining carbon derived from the silane compound after washing of the treated magnetic material with styrene is 0.40 mass % or more and 1.20 mass % or less with reference to the magnetic iron oxide.

8. A developing apparatus according to claim 5 , wherein:
the silane compound comprises a compound obtained by subjecting an alkoxysilane to hydrolysis treatment; and
the alkoxysilane has a hydrolysis ratio of 50% or more.

9. A developing apparatus according to claim 1 , wherein:
the toner particles each have a core-shell structure having a core and a shell; and
a resin for forming the shell comprises a polyester-based resin having an acid value of 0.1 mgKOH/g or more and 5.0 mgKOH/g or less.

10. A developing method, comprising developing an electrostatic latent image formed on a surface of an electrostatic latent image bearing member with a developing apparatus to form a toner image on the surface of the electrostatic latent image bearing member,
wherein:
the developing apparatus includes
a toner for developing the electrostatic latent image,
a toner carrier for carrying the toner, and
a regulating member for regulating a layer thickness of the toner carried by the toner carrier;
the toner comprises a toner containing
toner particles each containing a binder resin and a magnetic material, and
inorganic fine particles present on surfaces of the toner particles;

the toner has a dielectric loss factor (∈″) at a frequency of 100 kHz and a temperature of 30° C. of 0.03 pF/m or more and 0.30 pF/m or less;
the toner carrier includes
a substrate,
an elastic layer, and
a surface layer containing a urethane resin; and

the urethane resin has a partial structure derived from a reaction between
a compound represented by the following structural formula (1) and
a polyisocyanate:

in the structural formula (1):
n represents an integer of 1 or more and 4 or less;
R 3 's each independently represent a group selected from the group consisting of the following (a) to (c):

(a) a hydroxyalkyl group having 2 or more and 8 or less carbon atoms,
(b) an aminoalkyl group having 2 or more and 8 or less carbon atoms, and
(c) a group represented by the following structural formula (2); and
R 4 represents an alkylene group having 2 or more and 4 or less carbon atoms:

in the structural formula (2):
m is 2 or 3; and
R 5 represents an alkylene group having 2 or more and 5 or less carbon atoms.

11. A developing method according to claim 10 , wherein the dielectric loss factor (∈″) of the toner at a frequency of 100 kHz and a temperature of 30° C. is 0.05 pF/m or more and 0.25 pF/m or less.

12. A developing method according to claim 10 , wherein the toner has a dielectric constant (∈′) of 25 or more and 35 or less.

13. A developing method according to claim 10 , wherein the toner has a moisture adsorption amount at a temperature of 30° C. and a humidity of 90% of 2.5 mg/g or less.

14. A developing method according to claim 10 , wherein the magnetic material comprises a treated magnetic material obtained by treating a surface of magnetic iron oxide with a silane compound.

15. A developing method according to claim 14 , wherein:
the magnetic iron oxide has a silicon atom on the surface; and
an amount of silicon to be eluted when the magnetic iron oxide is dissolved until a dissolution ratio of an iron atom becomes 5 mass % is 0.05 mass % or more and 0.50 mass % or less with reference to the magnetic iron oxide.

16. A developing method according to claim 14 , wherein an amount of remaining carbon derived from the silane compound after washing of the treated magnetic material with styrene is 0.40 mass % or more and 1.20 mass % or less with reference to the magnetic iron oxide.

17. A developing method according to claim 14 , wherein:
the silane compound comprises a compound obtained by subjecting an alkoxysilane to hydrolysis treatment; and
the alkoxysilane has a hydrolysis ratio of 50% or more.

18. A developing method according to claim 10 , wherein:
the toner particles each have a core-shell structure having a core and a shell; and
a resin for forming the shell comprises a polyester-based resin having an acid value of 0.1 mgKOH/g or more and 5.0 mgKOH/g or less.

Assignees

• Canon Kk

Inventors

• Matsui Takashi
• Magome Michihisa
• Uratani Kozue
• Ohmori Atsuhiko
• Yamada Masaki
• Ito Minoru

Classifications

• G03G9/09328

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• G03G9/0836

  Other physical parameters of the magnetic components · CPC title

• G03G9/09385

  Inorganic compounds · CPC title

• G03G15/0818 Primary

  characterised by the structure of the donor member, e.g. surface properties · CPC title

• G03G9/0834

  Non-magnetic inorganic compounds chemically incorporated in magnetic components · CPC title