# US 9,753,386 B2 · Positively chargeable toner

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- Number: US 9,753,386 B2
- Document ID: US9753386B2
- Status: Granted
- Kind: B2
- Application number: 15/197,887
- Filed: 2016-06-30
- Published: 2017-01-05
- Granted: 2017-09-05
- Earliest claimed: 2015-07-02
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Haruhiro Nishitera
- Web page: https://patentgrep.com/patent/US9753386B2

## CPC

- G03G 9/0823: {Electric parameters}
- G03G 9/09321: {obtained by reactions only involving carbon-to-carbon unsaturated bonds}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A positively chargeable toner contains plural toner particles each containing a core, and a shell layer disposed over the core. The shell layer contains a first resin containing at least one repeating unit having an amide group, and a second resin containing at least one repeating unit having a quaternary ammonium cation. The toner attains a charge amount Q3 after stirring for 3 minutes and attains a charge amount Q30 after stirring for 30 minutes, and “Q30≦Q3” and “20 μC/g≦Q3” are both satisfied. Assuming that a second mixture of 100 parts by mass of the standard carrier and 10 parts by mass of the toner charged to a saturated charge amount is born on a development roller to measure a charge amount distribution, an arithmetic mean X and a standard deviation Y of the charge amount distribution satisfy “Y/X≦3.5”.

## Claims

### Claim 1

A positively chargeable toner comprising a plurality of toner particles each containing a core, and a shell layer disposed over a surface of the core, wherein
the shell layer contains a first resin containing at least one repeating unit having an amide group, and a second resin containing at least one repeating unit having a quaternary ammonium cation,
the first resin is a copolymer of styrene, butyl acrylate, and acrylamide at a mass ratio of 9:1:1,
the second resin is a copolymer of methyl methacrylate, butyl acrylate, and 2-(methacryloyloxy)ethyl trimethyl ammonium chloride at a mass ratio of 20:7:6,
the shell layer contains first resin particles substantially made of the first resin, and second resin particles substantially made of the second resin, and
a ratio of the first resin particles in the shell layer is 0.5% by mass or more and 5.0% by mass or less, and a ratio of the second resin particles in the shell layer is 95.0% by mass or more and 99.5% by mass or less.

### Claim 2

A positively chargeable toner comprising a plurality of toner particles each containing a core, and a shell layer disposed over a surface of the core, wherein
the shell layer contains a first resin containing at least one repeating unit having an amide group, and a second resin containing at least one repeating unit having a quaternary ammonium cation,
in a case where a first mixture of 100 parts by mass of a standard carrier and 10 parts by mass of the toner is stirred under an environment of a temperature of 23° C. and a humidity of 60% RH using a shaker mixer, the toner attains, in the first mixture, a charge amount Q3 after stirring for 3 minutes and attains a charge amount Q30 after stirring for 30 minutes, and both relationships of “Q30≦Q3” and “20 μC/g≦Q3” are satisfied,
in a case where a second mixture of 100 parts by mass of the standard carrier and 10 parts by mass of the toner having been charged to a saturated charge amount is born on a development roller to measure a charge amount distribution of the toner in the second mixture, an arithmetic mean X and a standard deviation Y of the charge amount distribution satisfy a relationship of “Y/X≦3.5”,
the shell layer contains first resin particles substantially made of the first resin, and second resin particles substantially made of the second resin,
the first resin is a copolymer of a styrene-based monomer, an acrylic acid alkyl ester monomer, and an acrylamide, and
the second resin is a copolymer of a (meth)acryloyl group-containing quaternary ammonium compound monomer, a methacrylic acid alkyl ester monomer containing, in an ester portion thereof, an alkyl group having 1 or 2 carbon atoms, and an acrylic acid alkyl ester monomer containing, in an ester portion thereof, an alkyl group having at least 3 and no greater than 6 carbon atoms.

### Claim 3 (depends on 1)

The positively chargeable toner according to claim 1, wherein
the first resin and the second resin each are a resin containing merely at least one repeating unit not having a hydroxyl group.