# US 8,273,515 B2 · Toner and method of manufacturing the same, two-component developer, developing device and image forming apparatus

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- Number: US 8,273,515 B2
- Document ID: US8273515B2
- Status: Granted
- Kind: B2
- Application number: 12/621,049
- Filed: 2009-11-18
- Published: 2010-05-20
- Granted: 2012-09-25
- Earliest claimed: 2008-11-19
- Assignees: Sharp Kabushiki Kaisha
- Inventors: Satoru Ariyoshi; Katsuru Matsumoto
- Web page: https://patentgrep.com/patent/US8273515B2

## CPC

- G03G 9/081: {by mixing the toner components in a liquefied state; melt kneading; reactive mixing}
- G03G 9/087: Binders for toner particles
- G03G 9/08775: {Natural macromolecular compounds or derivatives thereof}
- G03G 9/08777: {Cellulose or derivatives thereof}
- 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 2215/0604: solid type
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A toner containing a lignin resin, a carbon-neutral biomass polymer having a low environmental load and taking global environmental protection into account, as a constitutional component of a binder resin, and having a wide fixing non-offset range and an excellent fixing property, is provided. The toner contains at least a binder resin, a colorant, and a release agent. Furthermore, in the toner, the binder resin includes a resin A that is a lignin resin and a resin B that is another resin component, and the resin B has a peak top molecular weight of 103 to 104 and an acid number of 20 or less.

## Claims

### Claim 1

A toner comprising toner particles comprising at least a binder resin, a colorant and a release agent,
the binder resin comprising a resin A that is a lignin resin and a resin B that is another resin component,
the resin A being selected from the group of lignin digested with acetic acid, digested and blasted lignin, kraft lignin, lignosulfonic acid, and organosolv lignin, and
the resin B being a polyester resin and having a peak top molecular weight of 103 to 104 and an acid number of 20 or less,
wherein the toner particles are obtained by mixing, melt-kneading and pulverizing the binder resin, the colorant and the release agent.

### Claim 2 (depends on 1)

The toner of claim 1, wherein a ratio of the resin A in the binder resin is 20 to 50% by weight.

### Claim 3 (depends on 1)

The toner of claim 1, wherein the lignin resin as the resin A is lignosulfonic acid.

### Claim 4 (depends on 1)

A method for manufacturing the toner of claim 1, comprising:
a pre-mixing step of mixing at least a binder resin including a resin A that is a lignin resin and a resin B that is another resin component, a colorant and a release agent to obtain a mixture;
a melt-kneading step of melt-kneading the mixture obtained in the pre-mixing step to obtain a melt-kneaded material;
a pulverizing step of pulverizing the melt-kneaded material obtained in the melt-kneading step to obtain a pulverized material; and
a classifying step of classifying the pulverized material obtained in the pulverizing step by removing excessively pulverized particles and coarse particles therefrom.

### Claim 5 (depends on 1)

A two-component developer comprising the toner of claim 1 and a carrier.

### Claim 6 (depends on 1)

The toner of claim 1, wherein the polyester resin has a glass transition temperature of the range of 30 to 80° C. and a softening temperature of the range of 60 to 120° C.

### Claim 7 (depends on 6)

The toner of claim 6, wherein the polyester resin has a molecular weight distribution index Mw/Mn of 2.8, the molecular weigh distribution index Mw/Mn being a ratio or weight average molecular weight Mw to number average molecular weight Mn.