# US 9,519,237 B2 · Electrostatic latent image developing toner, method for manufacturing electrostatic latent image developing toner, and method for fixing electrostatic latent image developing toner

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- Number: US 9,519,237 B2
- Document ID: US9519237B2
- Status: Granted
- Kind: B2
- Application number: 14/482,209
- Filed: 2014-09-10
- Published: 2015-03-12
- Granted: 2016-12-13
- Earliest claimed: 2013-09-11
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Seiji Okada
- Web page: https://patentgrep.com/patent/US9519237B2

## CPC

- G03G 9/09392: {Preparation thereof}
- G03G 9/09314: {Macromolecular compounds}
- G03G 9/09328: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds}
- G03G 9/09342: {Inorganic compounds}
- G03G 9/09371: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds}
- G03G 9/09708: {Inorganic compounds}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An electrostatic latent image developing toner includes toner particles. Each toner particle includes a toner core containing a binder resin, a shell layer coating a surface of the toner core, and needle-like inorganic particulates. Each shell layer contains a thermosetting resin, and the inorganic particulates are present within the shell layer. The inorganic particulates have: an aspect ratio of 1.25 or more and 2.5 or less; and an average major diameter and an average minor diameter of 300 nm or less.

## Claims

### Claim 1

A method for manufacturing an electrostatic latent image developing toner, comprising:
preparing toner cores containing a binder resin;
causing needle-like inorganic particulates to adhere to the respective toner cores; and
forming shell layers to coat surfaces of the respective toner cores and the inorganic particulates, wherein
the shell layers contain a thermosetting resin, and
the needle-like inorganic particulates are present between the toner cores and the shell layers, the inorganic particulates having
an aspect ratio of 1.25 or more and 2.5 or less, and
an average major diameter and an average minor diameter of 15 nm or more and 300 nm or less.

### Claim 2 (depends on 1)

A method for manufacturing an electrostatic latent image developing toner, according to claim 1, wherein
the forming of the shell layers involves
supplying a shell-layer-forming liquid to the surface of each toner core to which the needle-like inorganic particulates adhere, the shell-layer-forming liquid containing a monomer and/or a prepolymer of the thermosetting resin, and
resinifying the monomer and/or the prepolymer of the thermosetting resin.

### Claim 3 (depends on 1)

A method for manufacturing an electrostatic latent image developing toner, according to claim 1,
in the forming shell layers, the thermosetting resin contains a melamine resin or a urea resin.

### Claim 4 (depends on 1)

A method for manufacturing an electrostatic latent image developing toner, according to claim 1,
in the causing needle-like inorganic particulates to adhere to the respective toner cores, the toner cores are mixed with the inorganic particulates using a mixer.

### Claim 5 (depends on 2)

A method for manufacturing an electrostatic latent image developing toner, according to claim 2,
in the resinifying, the thermosetting resin is obtained through polymerization or condensation of the monomer and/or the prepolymer of the thermosetting resin.

### Claim 6 (depends on 1)

A method for manufacturing an electrostatic latent image developing toner, according to claim 1,
in the causing needle-like inorganic particulates to adhere to the respective toner cores, the inorganic particulates are not embedded in the toner cores.

### Claim 7 (depends on 2)

A method for manufacturing an electrostatic latent image developing toner, according to claim 2,
in the supplying a shell-layer-forming liquid, the shell-layer-forming liquid contains an aqueous medium.

### Claim 8 (depends on 7)

A method for manufacturing an electrostatic latent image developing toner, according to claim 7,
in the supplying a shell-layer-forming liquid, the aqueous medium is adjusted to pH 4.

### Claim 9 (depends on 8)

A method for manufacturing an electrostatic latent image developing toner, according to claim 8,
in the supplying a shell-layer-forming liquid, the monomer and/or the prepolymer of the thermosetting resin is added to the aqueous medium.

### Claim 10 (depends on 2)

A method for manufacturing an electrostatic latent image developing toner, according to claim 2,
in the supplying a shell-layer-forming liquid, the toner cores adhering to the inorganic particulates are added to the shell-layer-forming liquid.