Toner and two-component developer

• US 8,288,069 B2
• Filed: 11/05/2010
• Issued: 10/16/2012
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fujikawa, Hiroyuki, Nakamura, Kunihiko, Komatsu, Nozomu, Itakura, Takayuki, Shiotari, Yoshiaki, Ohtsu, Takeshi
• Primary Examiner(s): Le, Hoa V
• Application Number:
  US12/940,164
• Publication Number:
  US 20110136060A1
• Time in Patent Office: 711 Days
• Field of Search: 430/137.1, 430/137.18
• US Class Current: 430/137.1
• CPC Class Codes: G03G 9/0815 Post-treatment
• 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 9/08755 Polyesters
• CPC Class Codes: G03G 9/08782 Waxes
• CPC Class Codes: G03G 9/107 having magnetic components

Abstract

Provided is a toner including: toner particles each containing at least a binder resin and a wax; and an external additive, in which surfaces of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 1.0 nm or more and 30.0 nm or less; and the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×10⁻³ N/m or more and 1.0×10⁻¹ N/m or less:
I=P_α/(A×B×10⁶)  Eq. (1)
where I represents the surface tension index (N/m) of the toner, P_α represents a capillary pressure (N/m²) of the toner for the 45-vol % aqueous solution of methanol, A represents a specific surface area (m²/g) of the toner, and B represents a true density (g/cm³) of the toner.

Claims

1. A method for producing a toner which comprises toner particles each containing at least a binder resin and a wax, and an external additive, comprising:

melt kneading a binder resin, a wax, and a polymer having a structure obtained by reacting a vinyl-based resin component and a hydrocarbon compound;

cooling the molten kneaded product;

pulverizing the cooled product coarsely and pulverizing the coarsely pulverized product with a mechanical type pulverizer;

treating the surface of the resultant fine pulverized product with hot air, and then cooling the surface-treated product with cold air to provide toner particles, wherein a temperature of the hot air is 100°

C. or higher and 450°

C. or lower, a temperature of the cold air is −

50°

C. or higher and 10°

C. or lower, and the cold air has an absolute moisture content of 5 g/m³ or less; and

adding the external additive to the toner particles, wherein the surface of the toner particles have an average surface roughness (Ra) measured with a scanning probe microscope of 2.0 nm or more and 25.0 nm or less;

wherein the toner has a surface tension index I for a 45-vol % aqueous solution of methanol measured by a capillary suction time method and calculated from the following equation (1) of 5.0×

10-3 N/m or more and 1.0×

10-1 N/m or less;

I=Pα

/(A×

B×

106) 

 

Eq. (1)

where I represents the surface tension index (N/m) of the toner, Pa represents a capillary pressure (N/m2) of the toner for the 45-vol % aqueous solution of methanol, A represents a specific surface area (m2/g) of the toner, and B represents a true density (g/cm3) of the toner.

2. A method for producing a toner according to claim 1, wherein the surface of the toner particles have a ten point height of roughness (Rz) measured with a scanning probe microscope of 10 nm or more and 1,000 nm or less.

3. A method for producing a toner according to claim 1, wherein the abundance of the wax on a surface of the toner is 60% or more and 100% or less.