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

Patent metadata

Field	Value
Publication number	US-9442416-B2
Application number	US-201414568062-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 26, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Provided is a developing apparatus, including 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. The toner carrier is placed to be brought into contact with the electrostatic latent image bearing member. The toner carrier includes a substrate, an elastic layer, and a surface layer containing a urethane resin. The urethane resin has a partial structure derived from a reaction between a compound represented by the structural formula (1) and a polyisocyanate. The toner contains toner particles each containing a binder resin and a magnetic material, and inorganic fine particles. The toner has a weight average particle diameter (D4) of from 9.5 μm to 14.0 μm. The toner has a porosity of 50 or more and 56 or less.

First claim

What is claimed is:

1. An image-forming apparatus, comprising:
an electrostatic latent image bearing member;
a charging unit for charging a surface of the electrostatic latent image bearing member;
an image exposure unit for irradiating the charged surface of the electrostatic latent image bearing member with image exposure light to form an electrostatic latent image on the surface of the electrostatic latent image bearing member;
a developing apparatus for developing the electrostatic latent image formed on the surface of the electrostatic latent image bearing member to form a toner image on the surface of the electrostatic latent image bearing member;
a transferring unit for transferring the toner image formed on the surface of the electrostatic latent image bearing member onto a transfer material through or without through an intermediate transfer member; and
a fixing unit for fixing the toner image transferred onto the transfer material onto the transfer material,
the image-forming apparatus being configured to recover transfer residual toner on the surface of the electrostatic latent image bearing member after the transfer of the toner image with the developing apparatus,
wherein:
the developing apparatus includes
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 carrier is placed to be brought into contact with the electrostatic latent image bearing member;
the toner carrier includes
a substrate,
an elastic layer, and
a surface layer containing a urethane resin;

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

the toner comprises magnetic toner containing
toner particles each containing a binder resin and a magnetic material, and
inorganic fine particles;

the toner has a weight average particle diameter (D4) of 9.5 μm or more and 14.0 μm or less; and
a porosity of the toner obtained from the following mathematical expression (1) is 50 or more and 56 or less:
Porosity=((true density−tap density)/true density)×100  Mathematical expression (1)

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.

2. An image-forming apparatus according to claim 1 , wherein a ratio (D4/D1) of the weight average particle diameter (D4) of the toner to a number average particle diameter (D1) of the toner is 1.30 or less.

3. An image-forming apparatus according to claim 1 , wherein:
the toner contains fine particles having a number average particle diameter (D1) of primary particles of 100 nm or more and 2.0 μm or less; and
the fine particles comprise at least one kind of fine particles selected from the group consisting of resin fine particles, strontium titanate fine particles, barium titanate fine particles, and calcium titanate fine particles.

4. An image-forming method, comprising:
a charging step of charging a surface of an electrostatic latent image bearing member;
an image exposure step of irradiating the charged surface of the electrostatic latent image bearing member with image exposure light to form an electrostatic latent image on the surface of the electrostatic latent image bearing member;
a developing step of developing the electrostatic latent image formed on the surface of the electrostatic latent image bearing member with a developing apparatus to form a toner image on the surface of the electrostatic latent image bearing member;
a transferring step of transferring the toner image formed on the surface of the electrostatic latent image bearing member onto a transfer material through or without through an intermediate transfer member; and
a fixing step of fixing the toner image transferred onto the transfer material onto the transfer material,
the image-forming method including recovering transfer residual toner on the surface of the electrostatic latent image bearing member after the transfer of the toner image with the developing apparatus,
wherein:
the developing apparatus includes
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 carrier is placed to be brought into contact with the electrostatic latent image bearing member;
the toner carrier includes
a substrate,
an elastic layer, and
a surface layer containing a urethane resin;

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

the toner comprises magnetic toner containing
toner particles each containing a binder resin and a magnetic material, and
inorganic fine particles;
the toner has a weight average particle diameter (D4) of 9.5 μm or more and 14.0 μm or less; and

a porosity of the toner obtained from the following mathematical expression (1) is 50 or more and 56 or less:
Porosity=((true density−tap density)/true density)×100  Mathematical expression (1)

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.

5. An image-forming method according to claim 4 , wherein a ratio (D4/D1) of the weight average particle diameter (D4) of the toner to a number average particle diameter (D1) of the toner is 1.30 or less.

6. An image-forming method according to claim 4 , wherein:
the toner contains fine particles having a number average particle diameter (D1) of primary particles of 100 nm or more and 2.0 μm or less; and
the fine particles comprise at least one kind of fine particles selected from the group consisting of resin fine particles, strontium titanate fine particles, barium titanate fine particles, and calcium titanate fine particles.

7. An image-forming method according to claim 4 , wherein an absolute value (|V1−V2|) of a difference between a potential (V1) of the surface of the electrostatic latent image bearing member

Assignees

• Canon Kk

Inventors

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

Classifications

• G03G9/09708

  Inorganic compounds · CPC title

• G03G9/0819

  characterised by the dimensions of the particles · CPC title

• G03G9/0825

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

• G03G15/0812

  characterised by the developer regulating means, e.g. structure of doctor blade · CPC title

• G03G15/0808 Primary

  characterised by the developer supplying means, e.g. structure of developer supply roller · CPC title