Color toner

• US 7,288,348 B2
• Filed: 09/09/2004
• Issued: 10/30/2007
• Est. Priority Date: 09/12/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ishigami, Koh, Hashimoto, Akira, Fujikawa, Hiroyuki, Ida, Tetsuya, Komatsu, Nozomu, Sugahara, Nobuyoshi, Hayami, Kazuhiko, Ichikawa, Yasuhiro, Kobori, Takakuni, Tanikawa, Hirohide, Itakura, Takayuki
• Primary Examiner(s): Chapman; Mark A.
• Application Number:
  US10/936,565
• Publication Number:
  US 20050079429A1
• Time in Patent Office: 1,146 Days
• Field of Search: 430/45, 430/110.3, 430/110.4, 430/137.18, 430/137.2, 430/45.1
• US Class Current: 430/45.1
• CPC Class Codes: G03G 9/081 by mixing the toner components in a liquefied state; melt kneading; reactive mixing
• CPC Class Codes: G03G 9/0817 Separation; Classifying
• CPC Class Codes: G03G 9/0819 characterised by the dimensions of the particles
• CPC Class Codes: G03G 9/0821 characterised by physical parameters magnetic parameters G03G9/083
• CPC Class Codes: G03G 9/0825 characterised by their structure; characterised by non-homogenuous distribution of components microcapsular toners G03G9/093
• CPC Class Codes: G03G 9/0827 characterised by their shape, e.g. degree of sphericity
• CPC Class Codes: G03G 9/08704 Polyalkenes
• CPC Class Codes: G03G 9/08706 Polymers of alkenyl-aromatic compounds
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08782 Waxes
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature
• CPC Class Codes: G03G 9/09708 Inorganic compounds

Abstract

In a color toner having toner particles which have toner base particles containing a binder resin, a colorant and a wax, and inorganic fine particles, (i) in the toner base particles, particles having a circle-equivalent diameter of 3.00 μm or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950, (ii) in the particles having a circle-equivalent diameter of 3.00 μm or more in the toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and (iii) in the particles having a circle-equivalent diameter of 3.00 μm or more in the toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less. Also disclosed is a full-color image forming method making use of the toner.

Claims

1. A color toner comprising toner particles which comprise toner base particles containing at least a binder resin, a colorant and a wax, and inorganic fine particles, wherein;

(i) in said toner base particles, particles having a circle-equivalent diameter of 3.00 μ

m or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950;

(ii) in the particles having a circle-equivalent diameter of 3.00 μ

m or more in said toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and

(iii) in the particles having a circle-equivalent diameter of 3.00 μ

m or more in said toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less.

2. The color toner according to claim 1, wherein, in said toner base particles, particles having a circle-equivalent diameter of from 0.60 μ

m or more to less than 3.00 μ

m are present in a content A (% by number) which satisfies 0.1≦

A<

15.0 with respect to all toner base particles.

3. The color toner according to claim 1, wherein, in said toner base particles, particles having a circle-equivalent diameter of from 0.60 μ

m or more to less than 2.00 μ

m are present in a content B (% by number) and particles having a circle-equivalent diameter of from 2.00 μ

m or more to less than 3.00 μ

m are present in a content C (% by number) which B and C satisfy 0.5<

B/C<

15.0 with respect to all toner base particles.

4. The color toner according to claim 1, wherein said toner base particles have an average surface roughness of from 5.0 nm or more to less than 35.0 nm as measured with a scanning probe microscope.

5. The color toner according to claim 1, which has, in the endothermic curve measured by differential thermal analysis, one, or a plurality of, endothermic peak(s) in the range of from 30°

C. to 200°

C. and a maximum peak temperature of the endothermic peak(s) in the range of from 60°

C. to 110°

C.

6. The color toner according to claim 1, wherein said binder resin has at least a polyester unit.

7. The color toner according to claim 1, wherein said binder resin is a resin selected from the group consisting of (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, (c) a mixture of the hybrid resin and a vinyl polymer, (d) a mixture of a polyester resin and a vinyl polymer, (e) a mixture of the hybrid resin and a polyester resin and (f) a mixture of the hybrid resin, a polyester resin and a vinyl polymer.

8. The color toner according to claim 1, wherein said wax is a hydrocarbon wax.

9. The color toner according to claim 1, wherein said inorganic fine particles comprise at least titanium oxide.

10. The color toner according to claim 1, which has a light transmittance (%) in the range of from 10% to 80% which is of the light of 600 nm in wavelength with respect to a liquid dispersion prepared by dispersing said toner in an aqueous solution of 45% by volume of methanol.

11. The color toner according to claim 1, which is a non-magnetic toner.

12. The color toner according to claim 1, wherein said toner base particles are toner base particles obtained through at least:

a kneading step of melt-kneading a mixture containing the binder resin and the colorant, to obtain a kneaded product;

a cooling step of cooling the kneaded product obtained;

a crushing step of crushing the kneaded product cooled, to obtain a crushed product;

a pulverization step of finely pulverizing the resultant crushed product by the use of an air pulverizing means to form a finely pulverized product;

a classification step of classifying the resultant finely pulverized product by the use of a multi-division classifying means that utilizes the Coanda effect, to obtain a median powder; and

a surface modification step of subjecting the resultant median powder to surface modification of particles by the use of a surface modifying apparatus.

13. A full-color image forming method which forms an image by the use of at least a magenta toner, a yellow toner, a cyan toner and a black toner;

said toners each being a color toner comprising toner particles which comprise toner base particles containing at least a binder resin, a colorant and a wax, and inorganic fine particles, wherein;

(i) in said toner base particles, particles having a circle-equivalent diameter of 3.00 μ

m or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950;

(ii) in the particles having a circle-equivalent diameter of 3.00 μ

m or more in said toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and

(iii) in the particles having a circle-equivalent diameter of 3.00 μ

m or more in said toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less.