# US 7,608,379 B2 · Toner and manufacturing method thereof

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- Number: US 7,608,379 B2
- Document ID: US7608379B2
- Status: Granted
- Kind: B2
- Application number: 11/505,977
- Filed: 2006-08-18
- Published: 2007-03-22
- Granted: 2009-10-27
- Earliest claimed: 2005-08-18
- Assignees: Sharp Kabushiki Kaisha
- Inventors: Yoshitaka Kawase; Satoru Ariyoshi; Katsuru Matsumoto; Yoshinori Yamamoto
- Web page: https://patentgrep.com/patent/US7608379B2

## CPC

- G03G 9/08755: {Polyesters}
- G03G 9/0804: {whereby the components are brought together in a liquid dispersing medium}
- G03G 9/0808: {by dry mixing the toner components in solid or softened state}
- G03G 9/08793: {Crosslinked polymers}
- G03G 9/08795: {characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants}
- G03G 9/08797: {characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A toner of excellent anti-hot offsetting property, with no variety of the charging performance and suitable as a toner for the development of electrostatic images, and a manufacturing method thereof are provided. At first, a crosslinked resin at least containing a tetrahydrofuran insoluble component and a colorant are dry-kneaded. Next, the obtained kneaded resin product is mixed with an aqueous dispersant solution prepared in advance and they are heated, to form colorant-containing resin particles in a liquid mixture of the kneaded resin product and the aqueous dispersant solution. Then, the liquid mixture is cooled and the colorant-containing resin particles are separated from the liquid mixture.

## Claims

### Claim 1

A toner manufacturing method comprising:
a dry kneading step of dry kneading a crosslinked resin at least containing a tetrahydrofuran insoluble component and a colorant,
a granulating step of mixing a kneaded resin product obtained by the dry kneading and an aqueous dispersant solution containing a dispersant, and heating or heating and pressurizing them to form colorant-containing resin particles in the liquid mixture of the kneaded resin product and the aqueous dispersant solution,
a cooling step of cooling the liquid mixture containing the formed colorant-containing resin particles, and
a separation step of separating the colorant-containing resin particles from the liquid mixture.

### Claim 2 (depends on 1)

The toner manufacturing method of claim 1, wherein the crosslinked resin contains the tetrahydrofuran insoluble component by 0.5% by weight or more and 30% by weight or less.

### Claim 3 (depends on 1)

The toner manufacturing method of claim 1, wherein a softening point of the crosslinked resin is equal to or lower than 150° C.

### Claim 4 (depends on 1)

The toner manufacturing method of claim 1, wherein a softening point of the crosslinked resin is within a range of 60° C. to 150° C.

### Claim 5 (depends on 1)

The toner manufacturing method of claim 1, wherein a glass transition point of the crosslinked resin is within a range of 30° C. to 80° C.

### Claim 6 (depends on 1)

The toner manufacturing method of claim 1, wherein a glass transition point of the crosslinked resin is within a range of 40° C. to 70° C.

### Claim 7 (depends on 1)

The toner manufacturing method of claim 1, wherein a weight average molecular weight of the crosslinked resin is within a range of 5,000 to 500,000.

### Claim 8 (depends on 1)

The toner manufacturing method of claim 1, wherein the crosslinked resin is a crosslinked polyester resin.

### Claim 9 (depends on 1)

The toner manufacturing method of claim 1, wherein the dispersant is a water-soluble polymeric compound.

### Claim 10 (depends on 9)

The toner manufacturing method of claim 9, wherein a weight average molecular weight of the water-soluble polymeric compound is within a range of 5,000 to 50,000.

### Claim 11 (depends on 9)

The toner manufacturing method of claim 9, wherein a weight average molecular weight of the water-soluble polymeric compound is within a range of 5,000 to 20,000.

### Claim 12 (depends on 9)

The toner manufacturing method of claim 9, wherein the water-soluble polymeric compound is a polycarboxylic acid compound.

### Claim 13 (depends on 1)

The toner manufacturing method of claim 1, wherein a wax is further kneaded together with the crosslinked resin and the colorant in the dry kneading step.