Toner and method for producing toner

Patent metadata

Field	Value
Publication number	US-2023273541-A1
Application number	US-202318173408-A
Country	US
Kind code	A1
Filing date	Feb 23, 2023
Priority date	Feb 28, 2022
Publication date	Aug 31, 2023
Grant date	—

Abstract

The present disclosure provides a toner excellent in low-temperature fixability and excellent in durability under harsh environments of high-temperature and high-humidity, and a method for producing the toner. The toner can contain: a toner particle containing a binder resin, wax, and an inorganic oxide particle; and an external additive, wherein the inorganic oxide particle contains, as a main component, an oxide of at least one element selected from the group consisting of Si, Mg, Al, Ti, and Sr; when a thin piece obtained by cutting the toner with a microtome is observed with a transmission electron microscope (TEM), the major axis A of the inorganic oxide particle is 0.10 to 3.00 μm; and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration at a transmittance of light having a wavelength of 780 nm of 50% is 5.0 to 30.0% by volume.

First claim

What is claimed is:

1 . A toner comprising:
a toner particle containing a binder resin, wax, and an inorganic oxide particle; and an external additive, wherein the inorganic oxide particle contains, as a main component, an oxide of at least one element selected from the group consisting of Si, Mg, Al, Ti, and Sr; wherein,
when a thin piece obtained by cutting the toner with a microtome is observed with a transmission electron microscope (TEM), a major axis A of the inorganic oxide particle is 0.10 to 3.00 μm; and
in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration at a transmittance of light having a wavelength of 780 nm of 50% is 5.0 to 30.0% by volume.

2 . The toner according to claim 1 , comprising at least one wax selected from the group consisting of an ester wax and a hydrocarbon wax.

3 . The toner according to claim 1 , wherein when the thin piece is observed with a transmission electron microscope (TEM), a relationship between a shortest distance B between the inorganic oxide particle and a surface of the toner particle and a shortest distance C between a domain of the wax and the surface of the toner particle satisfies B<C.

4 . The toner according to claim 1 , wherein when the thin piece is observed with a transmission electron microscope (TEM), a relationship between a shortest distance B between the inorganic oxide particle and a surface of the toner particle and the major axis A of the inorganic oxide particle satisfies A>B.

5 . The toner according to claim 1 , wherein a relationship between a major axis D of the external additive and the major axis A of the inorganic oxide particle satisfies A>D.

6 . The toner according to claim 1 , wherein when the thin piece is observed with a transmission electron microscope (TEM), the inorganic oxide particle have a shape factor SF-1 of 140 or more.

7 . The toner according to claim 1 , wherein when the thin piece is observed with a transmission electron microscope (TEM), the inorganic oxide particle have a sharp portion.

8 . The toner of claim 1 , wherein the inorganic oxide particle are silica particles.

9 . The toner according to claim 1 , wherein the external additive has a heating loss between 200° C. and 400° C. as measured by thermogravimetry (TGA) of 0.5 to 8.0%.

10 . The toner according to claim 1 , wherein the binder resin is a styrene-acrylic resin.

11 . The toner according to claim 1 , wherein, in a molecular weight distribution of a tetrahydrofuran-soluble matter of the binder resin, two or more peaks or shoulders are present between a weight-average molecular weight Mw of 3,000 and a weight-average molecular weight Mw of 2,000,000.

12 . A method for producing a toner, the toner comprising a toner particle containing a binder resin, wax, and an inorganic oxide particle, and an external additive, the method comprising:
melt-kneading, wherein the inorganic oxide particle contains, as a main component, an oxide of at least one element selected from the group consisting of Si, Mg, Al, Ti, and Sr; when a thin piece obtained by cutting the toner with a microtome is observed with a transmission electron microscope (TEM), a major axis A of the inorganic oxide particle is 0.10 to 3.00 μm; and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration at a transmittance of light having a wavelength of 780 nm of 50% is 5.0 to 30.0% by volume.

Assignees

• Canon Kk

Inventors

• Tanaka Masatake
• Katsura Taiji
• Kawaguchi Shintaro
• Nozaki Dai

Classifications

• G03G9/0821 Primary

  characterised by physical parameters (magnetic parameters G03G9/083) · CPC title

• G03G9/08782

  Waxes · CPC title

• G03G9/09725 Primary

  Silicon-oxides; Silicates · CPC title

• G03G9/09708

  Inorganic compounds · CPC title

• G03G9/081

  by mixing the toner components in a liquefied state; melt kneading; reactive mixing · CPC title