Toner and method for manufacturing toner

Patent metadata

Field	Value
Publication number	US-9606462-B2
Application number	US-201514814873-A
Country	US
Kind code	B2
Filing date	Jul 31, 2015
Priority date	Aug 7, 2014
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

To provide a toner from which an image having a stable image density can be obtained with reduced occurrence of pollution of members, even when a toner container is filled with a larger amount of toner than a conventional amount for long-term use. A toner including a toner particle and an external additive containing an organic-inorganic composite fine particle and an inorganic fine particle A; wherein the organic-inorganic composite fine particle includes a resin particle and an inorganic fine particle B, the resin particle has a surface with a convex derived from the inorganic fine particle B; has a specific number average particle diameter (D1) and a specific shape factor SF-2; and has a specific fixed state to the toner particle; the organic-inorganic composite fine particle has a specific unit diffusion index on the toner particle surface; the inorganic fine particle A has a specific BET specific surface area.

First claim

What is claimed is:

1. A toner comprising a toner particle containing a binder resin, a colorant and a releasing agent, and an external additive containing (i) an organic-inorganic composite fine particle having a number average particle diameter (D1) of 50-500 nm and a shape factor SF-2 of 103-120 as measured at a magnification of 200,000, and (ii) an inorganic fine particle A having a BET specific surface area of 50-400 m 2 /g, wherein
the organic-inorganic composite fine particle:
(1) comprises a resin particle and an inorganic fine particle B which is embedded in the resin particle, and has a surface with a convex portion derived from the inorganic fine particle B;
(2) has a proportion Y (parts by mass) of a particle firmly fixed to the toner particle of 0.45 to 3.00 parts by mass with respect to 100 parts by mass of the toner particle; and
(3) X-Y≦0.30 when a content proportion of the organic-inorganic composite fine particle is X parts by mass with respect to 100 parts by mass of the toner particle;
the organic-inorganic composite fine particle has a unit diffusion index of 0.75 or more on the toner particle surface when unit diffusion index=(organic-inorganic composite fine particle coverage ratio on toner particle surface obtained from measurement)/(organic-inorganic composite fine particle coverage ratio on toner particle surface for ideal diffusion of organic-inorganic composite fine particle).

2. A method for manufacturing a toner including a toner particle containing a binder resin, a colorant and a releasing agent, and an external additive containing (i) an organic-inorganic composite fine particle having a number average particle diameter (D1) of 50-500 nm and a shape factor SF-2 of 103-120 as measured at a magnification of 200,000, and (ii) an inorganic fine particle A having a BET specific surface area of 50-400 m 2 /g, comprising:
(A) a first mixing step of mixing the toner particle and the organic-inorganic composite fine particle using a treating apparatus having a rotator in a treatment chamber so as to produce a mixture; and
(B) a second mixing step of mixing the mixture and the inorganic fine particle A using a treating apparatus having a rotator in a treatment chamber so as to produce a toner, wherein
the organic-inorganic composite fine particle:
(1) comprises a resin particle and an inorganic fine particle B which is embedded in the resin particle, and has a surface with a convex portion derived from the inorganic fine particle B;
(2) has a proportion Y (parts by mass) of a particle firmly fixed to the toner particle of 0.45 to 3.00 parts by mass with respect to 100 parts by mass of the toner particle; and
(3) X-Y≦0.30 when a content proportion of the organic-inorganic composite fine particle is X parts by mass with respect to 100 parts by mass of the toner particle;
the organic-inorganic composite fine particle has a unit diffusion index of 0.75 or more on the toner particle surface when unit diffusion index=(organic-inorganic composite fine particle coverage ratio on toner particle surface obtained from measurement)/(organic-inorganic composite fine particle coverage ratio on toner particle surface for ideal diffusion of organic-inorganic composite fine particle).

3. The method for manufacturing a toner according to claim 2 , wherein the rotator of the treating apparatus for use in the first mixing step comprises a rotator body and a treatment surface for treating objects to be treated by collision with the objects to be treated caused by the rotation of the rotator;
the treatment surface extends outward from the outer peripheral surface of the rotator body in the radial direction, and has a region remote from the rotator body on the downstream side in the rotating direction of the rotator, in comparison with a region closer to the rotator body than the former region.

4. The method for manufacturing a toner according to claim 3 , in the cross section of the treatment chamber in the direction orthogonal to the rotation axis of the rotator, at a position where the treatment surface of the rotator is present, 0.80 L≦r≦L
when L represents the radius of a circle formed by the inner peripheral surface of the treatment chamber, and r represents the distance from the center of the circle formed by the inner peripheral surface of the treatment chamber to the end position of the treatment surface farthest from the rotator body.

5. The method for manufacturing a toner according to claim 4 , in the cross section of the treatment chamber in the direction orthogonal to the rotation axis of the rotator, at a position where the treatment surface of the rotator is present, R≧0.60 L and r≦0.99 L
when L represents the radius of a circle formed by the inner peripheral surface of the treatment chamber, R represents the distance from the center of a circle formed by the inner peripheral surface of the treatment chamber to a first region of the treatment surface closest to the rotator body, and r represents the distance from the center of the circle formed by the inner peripheral surface of the treatment chamber to the end position of the treatment surface farthest from the rotator body.

6. The method for manufacturing a toner according to claim 3 , in the cross section of the treatment chamber in the direction orthogonal to the rotation axis of the rotator, at a position where the treatment surface of the rotator is present, an angle formed between a line a and a line b is larger than 90° and 130° or less on the downstream side in the rotation direction,
wherein L represents the radius of a circle formed by the inner peripheral surface of the treatment chamber,
the line a connects a first region on the treatment surface closest to the rotator body with a second region on the treatment surface located at a position 0.80 L away from the center of the circle on the treatment surface,
the line b is the tangent line of a concentric circle passing through the second region at the second region,
the concentric circle is concentric with the circle.

Assignees

• Canon Kk

Inventors

• Nomura Shotaro
• Nishikawa Koji
• Fukudome Kosuke
• Yoshiba Daisuke
• Tsuda Shohei
• Akiyama Hiroki
• Yamazaki Katsuhisa

Classifications

• G03G9/0827

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

• G03G9/09733

  Organic compounds (G03G9/08782 takes precedence) · CPC title

• G03G9/09708

  Inorganic compounds · CPC title

• G03G9/0808 Primary

  by dry mixing the toner components in solid or softened state · CPC title

• G03G9/0825 Primary

  characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093) · CPC title