Toner and toner production method

Patent metadata

Field	Value
Publication number	US-12547089-B2
Application number	US-202318173357-A
Country	US
Kind code	B2
Filing date	Feb 23, 2023
Priority date	Feb 28, 2022
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

The subject toner includes a toner particle containing a binding resin and an inorganic oxide particle, wherein the inorganic oxide particle is a particle of an oxide containing at least one element selected from the group consisting of: Si; Mg; Al; Ti; and Sr, wherein, when an area of the inorganic oxide particle is represented by Sm and a sectional area of the toner is represented by St in a cross-section of the toner observed with a transmission electron microscope, Sm/St is 4.0% or more, wherein an area Sm of the inorganic oxide particle that occupies each of four regions obtained by dividing the cross-section of the toner by a long diameter of the toner and a perpendicular bisector of the long diameter has a standard deviation of 0.40 or more in the observed cross-section, and wherein the toner has an average circularity of 0.950 or more.

First claim

What is claimed is:

1 . A toner comprising:
a toner particle containing a binding resin, and an inorganic oxide particle, wherein the inorganic oxide particle is a particle of an oxide containing at least one element selected from the group consisting of: Si; Mg; Al; Ti; and Sr, wherein, when an area of the inorganic oxide particle is represented by Sm and a sectional area of the toner is represented by St in a cross-section of the toner observed with a transmission electron microscope, Sm/St is 4.0% or more, wherein an area Sm of the inorganic oxide particle that occupies each of four regions obtained by dividing the cross-section of the toner by a long diameter of the toner and a perpendicular bisector of the long diameter has a standard deviation of 0.40 or more in the observed cross-section, and wherein the toner has an average circularity of 0.950 or more.

2 . The toner according to claim 1 , wherein the inorganic oxide particle has a long diameter of 400 to 3,000 nm in the observed cross-section.

3 . The toner according to claim 1 , wherein the inorganic oxide particle includes a pointed portion in the observed cross-section.

4 . The toner according to claim 1 , wherein the inorganic oxide particle has a long diameter of 750 to 3,000 nm in the observed cross-section.

5 . The toner according to claim 1 , wherein the area Sm of the inorganic oxide particle has a standard deviation of 0.50 or more in the observed cross-section.

6 . The toner according to claim 1 , wherein the inorganic oxide particle is a silica particle.

7 . The toner according to claim 1 , wherein the inorganic oxide particle has a shape factor SF-1 of 140 or more in the observed cross-section.

8 . The toner according to claim 1 , wherein the toner has an average circularity of 0.960 or more.

9 . The toner according to claim 1 ,
wherein the toner further comprises an external additive, and wherein the external additive has a coating ratio of 75% or more.

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

11 . The toner according to claim 1 ,
wherein the binding resin is a styrene-acrylic resin, and wherein two or more of peaks or shoulders are present in a range of a weight-average molecular weight Mw of 3,000 to 2,000,000 in a molecular weight distribution of a tetrahydrofuran soluble component of the binding resin.

12 . A toner production method for producing a toner including a toner particle containing a binding resin and an inorganic oxide particle,
the production method comprising obtaining the toner particle, wherein the obtaining the toner particle includes obtaining a pre-hot-air surface treatment toner particle and subjecting the pre-hot-air surface treatment toner particle to surface treatment with hot air, wherein the obtaining a pre-hot-air surface treatment toner particle includes melting and kneading the binding resin and the inorganic oxide particle, wherein the inorganic oxide particle is a particle of an oxide containing at least one element selected from the group consisting of: Si; Mg; Al; Ti; and Sr, wherein, when an area of the inorganic oxide particle is represented by Sm and a sectional area of the toner is represented by St in a cross-section of the toner observed with a transmission electron microscope, Sm/St is 4.0% or more, wherein an area Sm of the inorganic oxide particle that occupies each of four regions obtained by dividing the cross-section of the toner by a long diameter of the toner and a perpendicular bisector of the long diameter has a standard deviation of 0.40 or more in the observed cross-section, and wherein the toner has an average circularity of 0.950 or more.

13 . The toner production method according to claim 12 , wherein the inorganic oxide particle includes a pointed portion in the observed cross-section.

14 . The toner production method according to claim 12 , wherein the inorganic oxide particle has a shape factor SF-1 of 140 or more in the observed cross-section.

Assignees

• Canon Kk

Inventors

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

Classifications

• G03G9/10882

  Binder is obtained by reactions only involving carbon-carbon unsaturated bonds · CPC title

• G03G9/0827

  characterised by their shape, e.g. degree of sphericity · CPC title

• G03G9/0817

  Separation; Classifying · CPC title

• G03G9/08711

  with esters of acrylic or methacrylic acid · CPC title

• G03G9/09725

  Silicon-oxides; Silicates · CPC title