Toner, production method of toner, image forming method, image forming apparatus, and process cartridge

Patent metadata

Field	Value
Publication number	US-10754270-B2
Application number	US-201816492818-A
Country	US
Kind code	B2
Filing date	Feb 15, 2018
Priority date	Mar 17, 2017
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

Provided is a toner including a binder resin, and a charge-controlling agent, wherein a volume average particle diameter X of the toner after a stress treatment satisfies Formula (1), and an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2).

First claim

The invention claimed is:

1. A toner comprising:
a binder resin; and
a charge-controlling agent,
wherein a volume average particle diameter X of the toner after a stress treatment below satisfies Formula (1) below, and
an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2) below,
6.0 ≤X (micrometers)≤8.5  Formula (1)

Y (% by mass)≤4.3 X (micrometers)−14.6  Formula (2)

where the stress treatment includes charging a container formed of polypropylene having a volume of 100 mL with 5 g of the toner and 10 g of alumina beads having particle diameters of 0.5 mm, and shaking the toner by shaking the container using a shaker (YS-8D, available from YAYOI Co., Ltd.) with a stroke width of 80 mm, a stroke number of 250 times/min, and a shaking duration of 1 hour.

2. The toner according to claim 1 ,
wherein the amount Y of the fine toner particles satisfies Formula (3) below,
Y (% by mass)≤3.8 X (micrometers)−14.6  Formula (3)

3. The toner according to claim 1 ,
wherein the amount Y of the fine toner particles satisfies Formula (4) below,
Y (% by mass)≤3.2 X (micrometers)−14.6  Formula (4)

4. The toner according to claim 1 ,
wherein the charge-controlling agent includes an azo iron dye.

5. The toner according to claim 1 ,
wherein the toner includes a THF-insoluble component in an amount of 10% by mass through 40% by mass,
a molecular-weight distribution of a THF-soluble component of the toner obtained by gel permeation chromatography (GPC) has a main peak between 10,000 and 16,000, where a half-value width of the main peak is a molecular weight of 60,000 through 90,000, and
within the THF-soluble component of the toner, a component having a molecular weight of 2,000 or less as determined by GPC is from 15.0% by mass through 25.0% by mass and a component having a molecular weight of 100,000 or greater as determined by GPC is 10.0% by mass or less.

6. A toner production method comprising:
kneading toner materials with melting the toner materials to obtain a melt-kneaded product;
pulverizing the melt-kneaded product to obtain a pulverized product; and
classifying the pulverized product obtained by the pulverizing,
wherein the toner production method is a method for producing the toner according to claim 1 ,
a volume average particle diameter X of the toner after a stress treatment below satisfies Formula (1), and
an amount Y of fine toner particles having particle diameters of 3 micrometers or smaller and circularity of 0.70 or less satisfies Formula (2).

7. An image forming method comprising:
forming an image by one-component development using the toner according to claim 1 .

8. An image forming apparatus comprising:
an electrostatic-latent-image bearer;
an electrostatic latent image-forming unit configured to form an electrostatic latent image on the electrostatic-latent-image bearer; and
a developing unit including a developer and configured to develop the electrostatic latent image with the developer to form a visible image,
wherein the developer includes the toner according to claim 1 .

9. A process cartridge comprising:
an electrostatic-latent-image bearer; and
a developing unit including a developer and configured to develop an electrostatic latent image formed on the electrostatic-latent-image bearer with the developer to form a visible image,
wherein the process cartridge is detachably mounted in a main body of an image forming apparatus, and
the developer includes the toner according to claim 1 .

Assignees

• Kitada Naoko
• Ogawa Satoshi
• Sekiguchi Yoshitaka
• Ishii Masayuki
• Kobayashi Shohta
• Ricoh Co Ltd

Inventors

• Kitada Naoko
• Ogawa Satoshi
• Sekiguchi Yoshitaka
• Ishii Masayuki
• Kobayashi Shohta

Classifications

• G03G9/0815 Primary

  Post-treatment · CPC title

• G03G9/0825

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

• G03G9/0817

  Separation; Classifying · CPC title

• G03G9/0827

  characterised by their shape, e.g. degree of sphericity · CPC title

• G03G9/081

  by mixing the toner components in a liquefied state; melt kneading; reactive mixing · CPC title