# US 2013/0157185 A1 · Toner, development agent, and image forming apparatus using the same

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- Number: US 2013/0157185 A1
- Document ID: US20130157185A1
- Status: Published application
- Kind: A1
- Application number: 13/705,811
- Filed: 2012-12-05
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Ricoh Company, Ltd.
- Inventors: Shingo SAKASHITA; Hiroshi Yamashita; Masahide Yamada; Shinya Nakayama; Atsushi Yamamoto; Yukiko Nakajima
- Web page: https://patentgrep.com/patent/US20130157185A1

## CPC

- G03G 9/08: with toner particles
- G03G 9/0821: {characterised by physical parameters (magnetic parameters G03G9/083)}
- G03G 9/08755: {Polyesters}
- G03G 9/08764: {Polyureas; Polyurethanes}
- G03G 9/08782: {Waxes}
- G03G 9/08788: {Block polymers}
- 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 9/097: Plasticisers; Charge controlling agents
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A toner includes a binder resin, a coloring agent, and a releasing agent containing two or more kinds of alkyl monoester compounds having a different number of carbon atoms in a range of from 30 to 50 carbon atoms. The toner has a crystallinity of 10% or more as measured by x-ray diffraction and/or the binder resin is a crystalline resin in an amount of 50% by weight or more of the binder resin. The two or more kinds of alkyl monoester compounds include a component A accounting for the largest amount ranging from 30% by weight to less than 50% by weight of the releasing agent and a component B accounting for the second largest amount ranging from 10% by weight to less than 50% by weight of the releasing agent.

## Claims

### Claim 1

A toner comprising:
a binder resin;
a coloring agent; and
a releasing agent comprising two or more kinds of alkyl monoester compounds having a different number of carbon atoms in a range of from 30 to 50 carbon atoms,
the toner having a crystallinity of 10% or more as measured by x-ray diffraction and/or the binder resin comprising a crystalline resin in an amount of 50% by weight or more of the binder resin,
the two or more kinds of alkyl monoester compounds including a component A accounting for the largest amount ranging from 30% by weight to less than 50% by weight of the releasing agent and a component B accounting for the second largest amount ranging from 10% by weight to less than 50% by weight of the releasing agent.

### Claim 2 (depends on 1)

The toner according to claim 1, wherein an absolute difference between the number of carbon atoms Na in the component A and the number of carbon atoms Nb in the component B ranges from 1 to 12.

### Claim 3 (depends on 1)

The toner according to claim 1, wherein the component A and the component B combined account for 90% by weight or more of the releasing agent.

### Claim 4 (depends on 1)

The toner according to claim 1, wherein the two or more kinds of alkyl monoester compounds further comprises a component C having 30 to 50 carbon atoms different from those of the component A and the component B,
wherein the component A, the component B, and the component C combined account for 95% by weight of the releasing agent.

### Claim 5 (depends on 1)

The toner according to claim 1, wherein the two or more kinds of alkyl monoester compounds are obtained by esterification reaction of a long chain aliphatic carboxylic acid component having 14 to 30 carbon atoms and a long chain aliphatic alcohol component having 16 to 36 carbon atoms.

### Claim 6 (depends on 1)

The toner according to claim 1, wherein the crystalline resin has at least one of a urethane bonding and a urea bonding

### Claim 7 (depends on 1)

The toner according to claim 1, wherein the crystalline resin comprises a crystalline resin D and a crystalline resin E, which have different weight average molecular weights (Mw).

### Claim 8 (depends on 1)

The toner according to claim 1, wherein crystallinity ranges from 15% to 30%.

### Claim 9 (depends on 1)

The toner according to claim 1, wherein the crystalline resin comprises a urethane-modified crystalline polyester resin obtained by elongation and cross-linking in reaction of a two or higher isocyanate compound and a polyester resin obtained by polycondensation of an alcohol component and a carboxylic acid component.

### Claim 10 (depends on 1)

The toner according to claim 1, wherein the crystalline resin comprises a block polymer of a polyester and a polyurethane.

### Claim 11 (depends on 1)

A development agent comprising the toner of claim 1.

### Claim 12 (depends on 1)

An image forming apparatus comprising:
an image bearing member;
a charger to charge a surface of the image bearing member;
an irradiator to irradiate the surface of the image bearing member with light to form a latent electrostatic image thereon;
a development device to develop the latent electrostatic image with the toner of claim 1 to obtain a visual image;
a transfer device to transfer the visual image to a recording medium; and
a fixing device to fix the visual image on the recording medium.