# US 12,461,462 B2 · White toner, electrostatic charge image developer, and toner cartridge

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- Number: US 12,461,462 B2
- Document ID: US12461462B2
- Status: Granted
- Kind: B2
- Application number: 17/586,796
- Filed: 2022-01-28
- Published: 2023-03-23
- Granted: 2025-11-04
- Earliest claimed: 2021-09-21
- Assignees: FUJIFILM Business Innovation Corp.
- Applicants: FUJIFILM Business Innovation Corp.
- Inventors: Asafumi Fujita; Teppei Yawada; Kotaro Yoshihara; Tsuyoshi Murakami
- Web page: https://patentgrep.com/patent/US12461462B2

## CPC

- G03G 9/08788: {Block polymers}
- G03G 9/0821: {characterised by physical parameters (magnetic parameters G03G9/083)}
- G03G 9/08755: {Polyesters}
- G03G 9/08797: {characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature}
- G03G 9/09708: {Inorganic compounds}
- G03G 15/0126: {using a solid developer}
- G03G 15/0865: {Arrangements for supplying new developer}
- G03G 15/6585: {by using non-standard toners, e.g. transparent toner, gloss adding devices}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A white toner includes a toner particle that contains a binder resin containing a hybrid resin in which an amorphous resin unit and a crystalline polyester resin unit are chemically bonded to each other, surface-treated titanium oxide, and a release agent, in which a proportion of Al atoms in a surface of the surface-treated titanium oxide is 3 atomic % or greater and 20 atomic % or less, and a proportion of Ti atoms in the surface is 5 atomic % or greater and 15 atomic % or less.

## Claims

### Claim 1

A white toner comprising:
a toner particle that contains a binder resin containing a hybrid resin in which an amorphous resin unit and a crystalline polyester resin unit are chemically bonded to each other, surface-treated titanium oxide, and a release agent,
wherein a proportion of Al atoms in a surface of the surface-treated titanium oxide is 3 atomic % or greater and 20 atomic % or less, and a proportion of Ti atoms in the surface is 5 atomic % or greater and 15 atomic % or less,
wherein a ratio (Al/Ti) of an atomic weight of Al to an atomic weight of Ti in the surface of the surface-treated titanium oxide is 1.5 or greater and 4.0 or less.

### Claim 2 (depends on 1)

The white toner according to claim 1,
wherein the proportion of Al atoms in the surface of the surface-treated titanium oxide is 5 atomic % or greater and 15 atomic % or less, and the proportion of Ti atoms in the surface is 6 atomic % or greater and 12 atomic % or less.

### Claim 3 (depends on 1)

The white toner according to claim 1,
wherein a ratio (Al/Ti) of an atomic weight of Al to an atomic weight of Ti in the surface of the surface-treated titanium oxide is 1.5 or greater and 3.5 or less.

### Claim 4 (depends on 1)

The white toner according to claim 1,
wherein a proportion of the amorphous resin unit in the hybrid resin in terms of mass is 50% by mass or greater and 90% by mass or less.

### Claim 5 (depends on 1)

The white toner according to claim 1,
wherein a proportion of the amorphous resin unit in the hybrid resin in terms of mass is 60% by mass or greater and 85% by mass or less.

### Claim 6 (depends on 1)

The white toner according to claim 1,
wherein a mass ratio (hybrid resin/surface-treated titanium oxide) of the hybrid resin to the surface-treated titanium oxide contained in the toner particle is 0.08 or greater and 3.0 or less.

### Claim 7 (depends on 1)

The white toner according to claim 1,
wherein a ratio (proportion of amorphous resin unit in terms of mass/proportion of Al atoms) of a proportion (% by mass) of the amorphous resin unit in the hybrid resin in terms of mass to the proportion (atomic %) of Al atoms in the surface of the surface-treated titanium oxide is 2.5 or greater and 3.0 or less.

### Claim 8 (depends on 1)

The white toner according to claim 1,
wherein a content of the hybrid resin contained in the toner particle is 5% by mass or greater and 60% by mass or less with respect to an entirety of the toner particle.

### Claim 9 (depends on 1)

The white toner according to claim 1,
wherein the surface-treated titanium oxide has an average major axis length of 20 nm or greater and 300 nm or less.

### Claim 10 (depends on 1)

The white toner according to claim 1,
wherein the surface-treated titanium oxide has a BET specific surface area of 4 m2/g or greater and 12 m2/g or less.

### Claim 11 (depends on 1)

The white toner according to claim 1,
wherein a content of the surface-treated titanium oxide contained in the toner particles is 20% by mass or greater and 60% by mass or less with respect to an entirety of the toner particle.

### Claim 12 (depends on 1)

An electrostatic charge image developer comprising:
the white toner according to claim 1.

### Claim 13 (depends on 1)

A toner cartridge comprising:
a container that accommodates the white toner according to claim 1,
wherein the toner cartridge is detachable from an image forming device.