Method for producing toner

Patent metadata

Field	Value
Publication number	US-9804519-B2
Application number	US-201615366295-A
Country	US
Kind code	B2
Filing date	Dec 1, 2016
Priority date	Dec 4, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method for producing a toner containing a toner particle containing a binder resin, a colorant and a crystalline substance, wherein the method includes the steps of: (I) setting a temperature of a dispersion, in which a coloring particle is dispersed with an aqueous medium, to T A (° C.), which is higher than the higher of a crystallization temperature Tc(° C.) of the crystalline substance and a glass transition temperature Tg(° C.) of the coloring particle, the coloring particle containing the binder resin, the colorant and the crystalline substance; (II) cooling the dispersion from the T A to a temperature equal to or lower than the Tg at a cooling rate of at least 5.0° C./min after the step (I); and (III) holding the dispersion in a temperature from Tg−10 to Tg+10 for at least 30 min after the step (II).

First claim

What is claimed is:

1. A method for producing a toner comprising a toner particle containing a binder resin, a colorant, and a crystalline substance, wherein
the method comprises the steps of:
(I) setting a temperature of a dispersion, in which a coloring particle is dispersed with an aqueous medium, to T A (° C.),
the T A (° C.) being higher than the higher of a crystallization temperature Tc(° C.) of the crystalline substance and a glass transition temperature Tg(° C.) of the coloring particle,
the coloring particle containing the binder resin, the colorant, and the crystalline substance;
(II) cooling the dispersion from the T A to a temperature equal to or lower than the Tg at a cooling rate of at least 5.0° C./min after the step (I); and
(III) holding the dispersion in a temperature range of at least Tg−10(° C.) and not more than Tg+10(° C.) for at least 30 min after the step (II).

2. The method for producing a toner according to claim 1 , wherein the crystalline substance satisfies at least one of the following (i) and (ii):
(i) a melting point Tm (° C.) of the crystalline substance is at least 50° C. and not more than 90° C.; and
(ii) a weight-average molecular weight (Mw) of the crystalline substance is at least 1,000, and a ratio of the weight-average molecular weight (Mw) of the crystalline substance to a number-average molecular weight (Mn) of the crystalline substance is at least 1.6.

3. The method for producing a toner according to claim 1 , wherein the dispersion comprises a poorly water-soluble inorganic dispersing agent.

4. The method for producing a toner according to claim 1 , wherein the binder resin comprises a styrene-acrylic resin.

5. The method for producing a toner according to claim 1 , wherein the T A is a temperature that is at least 5° C. and not more than 22° C. higher than the higher of the Tc (° C.) and the Tg (° C.).

6. The method for producing a toner according to claim 1 , wherein
the coloring particle contains an amorphous resin C which is different from the binder resin,
a content of the amorphous resin C is at least 1 mass part and not more than 10 mass parts, per 100 mass parts of the binder resin, and
a glass transition temperature Tgc (° C.) of the amorphous resin C is at least 10° C. higher than the Tg (° C.).

7. The method for producing a toner according to claim 1 , wherein the crystalline substance is an aliphatic hydrocarbon wax or an ester wax.

Assignees

• Canon Kk

Inventors

• Suzumura Yoshitaka
• Hasegawa Yusuke
• Sano Tomohisa
• Arimura Satoshi
• Ikejiri Takuma

Classifications

• G03G9/0804

  whereby the components are brought together in a liquid dispersing medium · CPC title

• G03G9/0825

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

• G03G9/08711

  with esters of acrylic or methacrylic acid · CPC title

• G03G9/0926 Primary

  characterised by physical or chemical properties · CPC title

• G03G9/091

  Azo dyes · CPC title