# US 8,465,896 B2 · Black toner

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,465,896 B2
- Document ID: US8465896B2
- Status: Granted
- Kind: B2
- Application number: 12/936,593
- Filed: 2010-02-19
- Published: 2011-02-24
- Granted: 2013-06-18
- Earliest claimed: 2009-02-27
- Assignees: Canon Kabushiki Kaisha
- Applicants: Ayako Sekikawa; Atsushi Tani; Takaaki Kaya; Shigeto Tamura; Makoto Kambayashi
- Inventors: Ayako Sekikawa; Atsushi Tani; Takaaki Kaya; Shigeto Tamura; Makoto Kambayashi
- Web page: https://patentgrep.com/patent/US8465896B2

## CPC

- G03G 9/0904: {Carbon black}
- G03G 9/08755: {Polyesters}
- G03G 9/08764: {Polyureas; Polyurethanes}
- G03G 9/08782: {Waxes}
- 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 9/0926: {characterised by physical or chemical properties}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A black toner has a toner particle including at least a resin (a) having a polyester as a main component, carbon black, and a wax, and a fine inorganic particle. When the Tgs of the black toner measured by DSC at temperature rise rate of 0.5° C./min and 4.0° C./min are defined as Tg(0.5) and Tg(4.0) respectively, Tg(0.5) is 35.0 to 60.0° C. and the difference between Tg(4.0) and Tg(0.5) is 2.0 to 10.0° C. When preparing a solution of which the black toner is dissolved in ethyl acetate and defined the concentration thereof as Cb1 (mg/mL) and the light absorbance thereof at 600 nm wavelength as A600, A600/Cb1 is less than 0.15. When preparing a solution of which the black toner is dissolved in chloroform and defined the concentration thereof as Cb2 (mg/mL) and the light absorbance thereof at 600 nm wavelength as A600, A600/Cb2 is 2.00 to 6.55.

## Claims

### Claim 1

A black toner comprising
a toner particle, which comprises at least a resin (a) having a polyester as a main component,
carbon black, and
a wax, and
a fine inorganic particle, wherein
when the glass transition temperatures of the black toner measured by DSC at a rate of temperature rise of 0.5° C./min and 4.0° C./min are defined as Tg(0.5) (° C.) and Tg(4.0) (° C.) respectively,
the Tg(0.5) is 35.0° C. or more to 60.0° C. or less, and
the difference between the Tg(4.0) and the Tg(0.5) [Tg(4.0)−Tg(0.5)] is 2.0° C. or more to 10.0° C. or less,
wherein,
when preparing a solution of which the black toner is dissolved in ethyl acetate, and defined the concentration thereof as Cb1 (mg/mL), and the light absorbance thereof at a wavelength of 600 nm as A600, the ratio of A600 to Cb1 (A600/Cb1) is less than 0.15, and
wherein,
when preparing a solution of which the black toner is dissolved in chloroform, and defined the concentration thereof as Cb2 (mg/mL), and the light absorbance thereof at a wavelength of 600 nm as A600, the ratio of A600 to Cb2 (A600/Cb2) is 2.00 or more to 6.55 or less.

### Claim 2 (depends on 1)

The black toner according to claim 1, wherein
the polyester included in the resin (a) having a polyester as a main component contains a diol unit as a constituent component, wherein the diol unit contains 50.0 mass % or more of an aliphatic diol unit having 4 to 12 (inclusive thereof) carbon atoms, and
the amount of water absorption of the black toner under an environment having a temperature of 40° C. and a humidity of 95% RH is 0.5 mass % or more to 1.5 mass % or less.

### Claim 3 (depends on 1)

The black toner according to claim 1, wherein that the amount of water absorption of the resin (a) under an environment having a temperature of 40° C. and a humidity of 95% RH is 0.5 mass % or more to 1.5 mass % or less.

### Claim 4 (depends on 1)

The black toner according to claim 1, wherein the acid value of the resin (a) is 20.0 mg KOH/g or less.

### Claim 5 (depends on 1)

The black toner according to claim 1, wherein the hydroxyl group value of the resin (a) is 20.0 mg KOH/g or more to 80.0 mg KOH/g or less.

### Claim 6 (depends on 1)

The black toner according to claim 1, wherein the carbon black has a content of 5.0 mass % or more to 15.0 mass % or less based on the toner particle.

### Claim 7 (depends on 1)

The black toner according to claim 1, wherein the black toner has a dielectric loss tangent (tan δ), represented by dielectric loss ε″/dielectric loss ε′, at a frequency of 100,000 Hz of 0.020 or less, and a volume resistivity of 1×1012 Ω·cm or more.

### Claim 8 (depends on 1)

The black toner according to claim 1, wherein a number average dispersion diameter of the carbon black in a cross-sectional photograph of the toner particle taken by a transmission electron microscope (TEM) is 100 nm or less to 500 nm or more.

### Claim 9 (depends on 1)

The black toner according to claim 1, wherein the toner particle is a capsule-type toner particle having a surface layer (B) having a urethane resin (b) as a main component on a surface of a toner base particle (A) having at least the resin (a) having a polyester as a main component, carbon black, and a wax.

### Claim 10 (depends on 9)

The black toner according to claim 9, wherein
the urethane resin (b) is a resin comprising a reaction product of a prepolymer diol component and a diisocyanate component, wherein when the total number of moles of the diol component is [OH] (mol), and the total number of moles of the isocyanate component is [NCO] (mol), the ratio of the [NCO] to the [OH] ([NCO]/[OH]) is 0.50 or more to 1.00 or less, and
the urethane resin (b) is a resin polymerized using at least 1.0 mass % or more to 30.0 mass % or less of a diol containing a carboxyl group and 10.0 mass % or more to 30.0 mass % or less of a diisocyanate.

### Claim 11 (depends on 9)

The black toner according to claim 9, wherein the amount of water absorption of the urethane resin (b) under an environment having a temperature of 40° C. and a humidity of 95% RH is 3.5 mass % or less.

### Claim 12 (depends on 9)

The black toner according to claim 9, wherein when an acid value Vb obtained by measuring a dissolved product of the urethane resin (b) dissolved in tetrahydrofuran by a titration method is Vb (mg KOH/g), the Vb is 10.0 mg KOH/g or more to 50.0 mg KOH/g or less.

### Claim 13 (depends on 1)

The black toner according to claim 1, wherein the toner particle is obtained by dissolving a dissolved product or a dispersion product obtained by dissolving or dispersing at least the resin (a) having a polyester as a main component, carbon black, and a wax in an organic medium in an aqueous medium in which resin fine particles having the urethane resin (b) as a main component are dispersed, removing the solvent from an obtained dispersion, and drying a resultant product.