# US 7,745,084 B2 · Toner, developer including the toner, and image forming method, image forming apparatus and process cartridge using the toner

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- Number: US 7,745,084 B2
- Document ID: US7745084B2
- Status: Granted
- Kind: B2
- Application number: 11/185,803
- Filed: 2005-07-21
- Published: 2006-02-02
- Granted: 2010-06-29
- Earliest claimed: 2004-07-30
- Assignees: Ricoh Company, Ltd.
- Inventors: Hideki Sugiura; Hitoshi Iwatsuki
- Web page: https://patentgrep.com/patent/US7745084B2

## CPC

- G03G 9/0808: {by dry mixing the toner components in solid or softened state}
- G03G 9/0806: {whereby chemical synthesis of at least one of the toner components takes place}
- G03G 9/0815: {Post-treatment}
- G03G 9/0819: {characterised by the dimensions of the particles}
- G03G 9/0821: {characterised by physical parameters (magnetic parameters G03G9/083)}
- G03G 9/0827: {characterised by their shape, e.g. degree of sphericity}
- G03G 9/08755: {Polyesters}
- G03G 9/08791: {characterised by the presence of specified groups or side chains}
- 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 9/09708: {Inorganic compounds}
- G03G 9/09716: {treated with organic compounds}
- G03G 9/09725: {Silicon-oxides; Silicates}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A toner including a binder resin and a colorant, wherein a pellet of the toner which is prepared by applying a pressure of 15 kg/cm2 to the toner has a tensile strength of from 900 Pa to 10,000 Pa, and wherein the toner has a methanol wettability of from 25 to 65% by volume, wherein the methanol wettability is measured by a method in which the toner is dispersed in a mixture solvent of water and methanol, and methanol is added to the toner dispersion while checking the transparency of the dispersion to determine a transparency fall starting point, wherein the methanol wettability is defined as {Vm/(Vm+Vw)}×100, wherein Vm represents a total volume (ml) of methanol in the dispersion at the transparency dropping point, and Vw represents the total volume of the pure water added.

## Claims

### Claim 1

A toner comprising:
a binder resin;
a colorant, and
a fluorine-containing compound,
wherein an atomic ratio (F/C) of a fluorine atom to a carbon atom at a surface of the toner is from 0.010 to 0.110,
wherein the fluorine-containing compound adheres to the binder resin or an ion of the fluorine-containing compound bonds with the binder resin, and the ion contains the fluorine atom
wherein a pellet of the toner which is prepared by applying a pressure of 15 kg/cm2 to the toner has a tensile strength of from 900 Pa to 10,000 Pa, and wherein the toner has a methanol wettability of from 25 to 65% by volume, wherein the methanol wettability is measured by a method in which (1) 0.5 g of the toner is dispersed in a mixture solvent of 42 ml of pure water and 18 ml of methanol; (2) the mixture is subjected to a dispersion treatment for 5 minutes using an ultrasonic dispersion machine to prepare a toner dispersion; and (3) methanol is added to the toner dispersion while checking a transparency of a mixture of methanol and the toner dispersion to determine a transparency dropping point of the toner dispersion, wherein the methanol wettability (MEW) is defined by the following equation:
MEW(% by volume)={Vm/(Vm+Vw)}×100,
wherein Vm represents a total volume (ml) of methanol in the mixture at the transparency dropping point, and Vw represents the total volume of pure water in the mixture.

### Claim 2 (depends on 1)

The toner according to claim 1, wherein the binder resin comprises a polyester resin.

### Claim 3 (depends on 2)

The toner according to claim 2, wherein the polyester resin comprises a modified polyester resin.

### Claim 4 (depends on 3)

The toner according to claim 3, wherein the polyester resin further comprises an unmodified polyester resin, and wherein a weight ratio of the modified polyester resin to the unmodified polyester resin is from 5/95 to 80/20.

### Claim 5 (depends on 1)

The toner according to claim 1, wherein the fluorine-containing compound is an ion having the following formula (I):
wherein X represents SO2— or CO—; each of R1, R2, R3 and R4 represents a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, or an aryl group having from 6 to 18 carbon atoms; and each of m and n is a positive integer.

### Claim 6 (depends on 1)

The toner according to claim 1, wherein the fluorine-containing compound is bonded with the polyester resin.

### Claim 7 (depends on 1)

The toner according to claim 1, wherein the toner is prepared by a method including the following steps:
reacting a toner composition comprising a polyester prepolymer with a crosslinking agent and/or a polymer chain extension agent in an aqueous medium to prepare a dispersion comprising a polyester resin; and
adding the fluorine-containing compound to the dispersion to adhere the fluorine-containing compound to the polyester resin or to bond an ion of the fluorine-containing compound with the polyester resin, wherein the ion contains a fluorine atom.

### Claim 8 (depends on 1)

The toner according to claim 1, further comprising a first hydrophobized particulate inorganic material having a primary particle diameter of from 30 to 150 nm, wherein the first hydrophobized particulate inorganic material is present at least on a surface of particles of the toner.

### Claim 9 (depends on 8)

The toner according to claim 8, further comprising a second hydrophobized particulate inorganic material having a primary particle diameter of from 1 to 20 nm, wherein the second hydrophobized particulate inorganic material is present at least on the surface of particles of the toner.

### Claim 10 (depends on 1)

The toner according to claim 1, wherein the toner has a circularity of from 0.90 to 0.99.

### Claim 11 (depends on 1)

The toner according to claim 1, wherein the toner has a first form factor SF-1 of from 103 to 150, and a second form factor SF-2 of from 101 to 140.

### Claim 12 (depends on 1)

The toner according to claim 1, wherein the toner has a volume average particle diameter of from 2 to 7 μm.

### Claim 13 (depends on 1)

The toner according to claim 1, wherein the toner has a ratio (Dv/Dn) of a volume average particle diameter (Dv) to a number average particle diameter (Dn) not greater than 1.15.

### Claim 14 (depends on 1)

A developer comprising the toner according to claim 1 and a carrier.

### Claim 15 (depends on 1)

An image forming apparatus comprising:
an image bearing member configured to bear an electrostatic latent image thereon;
a developing device configured to develop the electrostatic latent image with a developer comprising the toner according to claim 1 to form a toner image on the image bearing member; and
a transferring device configured to transfer the toner image onto a receiving material optionally via an intermediate transfer medium.

### Claim 16 (depends on 15)

The image forming apparatus according to claim 15, wherein the image bearing member is a photoreceptor comprising amorphous silicon.

### Claim 17 (depends on 15)

The image forming apparatus according to claim 15, further comprising a contact charging device configured to charge the image bearing member while contacting the image bearing member.

### Claim 18 (depends on 17)

The image forming apparatus according to claim 17, further comprising:
a fixing device configured to fix the toner image on the receiving material, wherein the fixing device comprises:
a heating member comprising a heater;
a film which contacts the heating member and which is configured to heat the receiving material having the toner image thereon while contacting the image; and
a pressing member configured to press the film toward the hearing member,
wherein the receiving material bearing the toner image thereon is passed through a nip between the film and the pressing member.

### Claim 19 (depends on 1)

A process cartridge comprising:
an image bearing member configured to bear an electrostatic latent image; and
a developing device configured to develop the latent image with a developer comprising the toner according to claim 1.

### Claim 20 (depends on 1)

An image forming method comprising:
forming an electrostatic latent image on an image bearing member;
developing the electrostatic latent image with a developer including the toner according to claim 1 to prepare a toner image;
transferring the toner image onto a receiving material optionally via an intermediate transfer medium.