# US 2018/0321606 A1 · Toner, developer, and image forming apparatus

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- Number: US 2018/0321606 A1
- Document ID: US20180321606A1
- Status: Published application
- Kind: A1
- Application number: 16/031,490
- Filed: 2018-07-10
- Published: 2018-11-08
- Earliest claimed: 2016-01-18
- Assignees: Ricoh Company, Ltd.
- Inventors: Koh OHNUMA; Tsuyoshi Sugimoto; Shinya Nakayama; Hideyuki Santo; Shin Hasegawa; Suzuka Karato; Kohsuke Nagata
- Web page: https://patentgrep.com/patent/US20180321606A1

## CPC

- G03G 9/08755: {Polyesters}
- G03G 9/08: with toner particles
- G03G 9/087: Binders for toner particles
- G03G 9/08786: {Graft polymers}
- G03G 9/08788: {Block polymers}
- G03G 9/08791: {characterised by the presence of specified groups or side chains}
- 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 15/0865: {Arrangements for supplying new developer}
- G03G 15/2064: {combined with pressure}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

Provided is a toner including a crystalline polyester resin including a constitutional unit derived from saturated aliphatic dicarboxylic acid and a constitutional unit derived from saturated aliphatic diol, an amorphous hybrid resin, an amorphous polyester resin, a release agent, and a colorant, wherein the crystalline polyester resin includes a constitutional unit derived from sebacic acid as the constitutional unit derived from the saturated aliphatic dicarboxylic acid, and the amorphous hybrid resin is a composite resin including a polyester-based resin unit and a styrene-based resin unit.

## Claims

### Claim 1

A toner comprising:
a crystalline polyester resin including a constitutional unit derived from saturated aliphatic dicarboxylic acid and a constitutional unit derived from saturated aliphatic diol;
an amorphous hybrid resin;
an amorphous polyester resin;
a release agent; and
a colorant,
wherein the crystalline polyester resin includes a constitutional unit derived from sebacic acid as the constitutional unit derived from the saturated aliphatic dicarboxylic acid, and
the amorphous hybrid resin is a composite resin including a polyester-based resin unit and a styrene-based resin unit.

### Claim 2 (depends on 1)

The toner according to claim 1,
wherein the crystalline polyester resin includes a constitutional unit derived from straight-chain aliphatic diol having from 2 through 8 carbon atoms as the constitutional unit derived from the saturated aliphatic diol.

### Claim 3 (depends on 1)

The toner according to claim 1,
wherein SP1, SP2, and SP3 satisfy formulae (1) to (3) below,
SP1<SP3<SP2 Formula (1)
0.4<SP2−SP1<1.1 Formula (2)
0.1<SP3−SP1<1.0 Formula (3)
where SP1 is an SP value of the crystalline polyester resin, SP2 is an SP value of the amorphous polyester resin, and SP3 is an SP value of the amorphous hybrid resin.

### Claim 4 (depends on 1)

The toner according to claim 1,
wherein a glass transition temperature (Tg1st) determined from a DSC curve of first heating as measured by differential scanning calorimetry (DSC) is from 45° C. through 55° C.

### Claim 5 (depends on 1)

A developer comprising:
the toner according to claim 1.

### Claim 6 (depends on 1)

A toner stored unit comprising:
a container; and
the toner according to claim 1, stored in the container.

### Claim 7 (depends on 1)

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 that includes a toner and is configured to develop the electrostatic latent image formed on the electrostatic latent image-bearer to form a visible image,
wherein the toner is the toner according to claim 1.

### Claim 8 (depends on 1)

An image forming method comprising:
forming an electrostatic latent image on an electrostatic latent image-bearer; and
developing the electrostatic latent image formed on the electrostatic latent image-bearer with a toner to form a toner image,
wherein the toner is the toner according to claim 1.