Toner

Patent metadata

Field	Value
Publication number	US-9720340-B2
Application number	US-201514707770-A
Country	US
Kind code	B2
Filing date	May 8, 2015
Priority date	May 14, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Provided is a toner that has satisfactory chargeability and hardly causes a reduction in image density, fogging, and density unevenness in various environments ranging from a low-temperature and low-humidity environment to a high-temperature and high-humidity environment. The toner includes toner particles obtained by fixing resin particles to toner base particles each containing resins, in which: the resins contain 50.0 mass % or more of a styrene-acrylic resin and 1.0 to 40.0 mass % of a polyester resin A; the polyester resin A contains 0.10 to 30.00 number % of an isosorbide unit; the fixing amount of the resin particles to the toner base particles is from 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the toner base particles; and the glass transition temperature of the resin particles is higher than the glass transition temperature of the toner base particles.

First claim

What is claimed is:

1. A toner, comprising:
toner particles, said toner particles comprising resin particles fixed to toner base particles, the toner base particles each comprising resins and a colorant, wherein
the resins comprise a styrene-acrylic resin and a polyester resin A,
a content of the styrene-acrylic resin is 50.0 mass % or more with reference to the resins,
a content of the polyester resin A is 1.0 to 40.0 mass % with reference to the resins,
the styrene-acrylic resin has a peak molecular weight (Mp) of 5,000 to 30,000,
the polyester resin A has a unit represented by formula (1), and a ratio of the unit represented by formula (1) is 0.10 to 30.00 number % with reference to the number of all units constituting the polyester resin A,

a fixing amount of the resin particles to the toner base particles is 0.1 to 5.0 parts by mass with respect to 100.0 parts by mass of the toner base particles, and
glass transition temperature of the resin particles Tg2 (° C.) is higher than glass transition temperature of the toner base particles Tg1 (° C.).

2. A toner according to claim 1 , wherein the polyester resin A has an acid value of 0.5 to 25.0 mgKOH/g.

3. A toner according to claim 1 , wherein the glass transition temperature Tg2 (° C.) of the resin particles is 60.0 to 105.0° C.

4. A toner according to claim 1 , wherein the glass transition temperature Tg1 (° C.) of the toner base particles is 50.0 to 58.0° C.

5. A toner according to claim 1 , wherein the styrene-acrylic resin comprises a copolymer of styrene and butyl acrylate.

6. A toner according to claim 1 , wherein the resin particles have a median diameter (D50) on a volume basis of 20 to 200 nm.

7. A toner according to claim 1 , wherein the toner base particles are obtained by forming particles of a polymerizable monomer composition containing the resin A, the colorant, and polymerizable monomers in an aqueous medium, and polymerizing the polymerizable monomers, and
the styrene-acrylic resin comprises a resin obtained from the polymerizable monomers.

Assignees

• Canon Kk

Inventors

• Tominaga Tsuneyoshi
• Katsuta Yasushi
• Nonaka Katsuyuki
• Katsura Taiji
• Masumoto Akane
• Takada Harumi
• Mizushima Kohei

Classifications

• G03G9/08797 Primary

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/08755

  Polyesters · CPC title

• G03G9/08711

  with esters of acrylic or methacrylic acid · CPC title

• G03G9/09371

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title