Full-color image-forming method

Patent metadata

Field	Value
Publication number	US-9304428-B2
Application number	US-201414226809-A
Country	US
Kind code	B2
Filing date	Mar 26, 2014
Priority date	Feb 2, 2007
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Provided are a toner containing at least a binder resin and a colorant, the toner having a specific hue angle and an absorbance at a specific wavelength in reflectance spectrophotometry, and a full-color image-forming method involving the use of the toner, the method including the steps of: forming an electrostatic image on a charged electrostatic image bearing member; developing the formed electrostatic image with the toner to form a toner image; transferring the formed toner image onto a transfer material; and fixing the transferred toner image to the transfer material to form a fixed image.

First claim

What is claimed is:

1. An image-forming method, comprising:
forming a black image by forming an electrostatic latent image on an electrostatic image bearing member, and developing the electrostatic latent image with a black toner; and
transferring the black image onto a transfer material,
wherein:
the black toner contains a binder resin and a colorant,
the colorant is contained in the black toner in an amount of from 8 parts by mass to 18 parts by mass based on 100 parts by mass of the binder resin, and
the colorant is dispersed in the binder resin so that the black toner has a value (c* K ) for c* based on a CIELAB color coordinate system of 20.0 or less, an absorbance (A K600 ) at a wavelength of 600 nm of 1.610 or more, and a ratio (A K600 /A K460 ) of A K600 to an absorbance (A K460 ) at a wavelength of 460 nm of 0.970 to 1.035 in reflectance spectrophotometry, and
wherein, when a true density of the black toner is represented by ρ TK and a toner amount upon development of image data represented by the CIELAB color coordinate system with L*=13.2, a*=1.3, and b*=1.9 onto the transfer material is represented by M1 K (mg/cm 2 ), a coloring coefficient A K represented by the following expression is 3.0 to 12.0
A K =A K600 /( M 1 K ×ρ TK ).

2. A full-color image-forming method, comprising the steps of:
forming each of a plurality of electrostatic images on a charged electrostatic image bearing member;
developing the formed electrostatic images with toners to form toner images;
transferring the formed toner images onto a transfer material; and
fixing the transferred toner images to the transfer material to form fixed images,
wherein:
the step of forming the toner images includes a step of performing development with a first toner selected from a black toner, a cyan toner, a magenta toner, and a yellow toner to form a first toner image, a step of performing development with a second toner except the first toner selected from the black toner, the cyan toner, the magenta toner, and the yellow toner to form a second toner image, a step of performing development with a third toner except the first toner and the second toner selected from the black toner, the cyan toner, the magenta toner, and the yellow toner to form a third toner image, and a step of performing development with a fourth toner except the first toner, the second toner, and the third toner selected from the black toner, the cyan toner, the magenta toner, and the yellow toner to form a fourth toner image;
the black toner contains at least a binder resin and a colorant, and the black toner has a value (c* K ) for c* based on a CIELAB color coordinate system of 20.0 or less, an absorbance (A K600 ) at a wavelength of 600 nm of 1.610 or more, and a ratio (A K600 /A K460 ) of A K600 to an absorbance (A K460 ) at a wavelength of 460 nm of 0.970 to 1.035 in reflectance spectrophotometry; and
the black toner contains the colorant of 8 to 18 parts by mass with respect to 100 parts by mass of the binder resin, and
wherein, when a true density of the black toner is represented by ρ TK and a toner amount upon development of image data represented by the CIELAB color coordinate system with L*=13.2, a*=1.3, and b*=1.9 onto the transfer material is represented by M1 K (mg/cm 2 ) a coefficient A K resented by the following expression is 3.0 to 12.0
A K =A K600 /( M 1 K ×ρ TK ).

3. A full-color image-forming method according to claim 2 , wherein the step of forming the toner images includes a step of transporting the toners to a developing portion with a toner carrying member and a step of developing the electrostatic images with the toners in the developing portion, and a ratio (Q K /A K600 ) of a charge quantity (Q K ) (mC/kg) of the black toner on the toner carrying member in the transporting step to A K600 is 22.0 to 50.0.

4. A full-color image-forming method according to claim 2 , wherein, in the step of forming the toner images, a ratio (H K80 /H K20 ) of an average height (H K80 ) of a toner layer of a toner image formed on the electrostatic image bearing member for image data having a black monochromatic density of 80% to an average height (H K20 ) of a toner layer of a toner image formed on the electrostatic image bearing member for image data having a black monochromatic density of 20% is 0.90 to 1.30.

5. An image-forming method, comprising:
forming a black image by forming an electrostatic latent image on an electrostatic image bearing member, and developing the electrostatic latent image with a black toner; and
transferring the black image onto a transfer material,
wherein:
the black toner contains a binder resin and a colorant,
the colorant is contained in the black toner in an amount of from 8 parts by mass to 18 parts by mass based on 100 parts by mass of the binder resin, and
the colorant is dispersed in the binder resin so that the black toner has a value (c* K ) for c* based on a CIELAB color coordinate system of 20.0 or less, an absorbance (A K600 ) at a wavelength of 600 nm of 1.610 or more, and a ratio (A K600 /A K460 ) of A K600 to an absorbance (A K460 ) at a wavelength of 460 nm of 0.970 to 1.035 in reflectance spectrophotometry,
wherein:
when
an average height of a first toner layer is defined as H K20 , where the first toner layer is formed by developing image data having black monochromatic density of 20% on the electrostatic image bearing member with the black toner, and
an average height of a second toner layer is defined as H K80 , where the second toner layer is formed by developing image date having black monochromatic density of 80% on the electrostatic image bearing member with the black toner,
said step is performed so that H K20 and H K80 satisfies the following relationship:
0.90≦ H K80 /H K20 ≦1.30, and

wherein, when a true density of the black toner is represented by ρ TK and a toner amount upon development of image data represented by the CIELAB color coordinate system with L*=13.2, a*=1.3, and b*=1.9 onto the transfer material is represented by M1 K (mg/cm 2 ), a coefficient A K represented by the following expression is 3.0 to 12.0
A K =A K600 /( M 1 K ×ρ TK ).

Assignees

• Canon Kk

Inventors

• Ayaki Yasukazu
• Tamura Shigeto

Classifications

• G03G9/0821 Primary

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

• G03G13/01 Primary

  for multicoloured copies {(colour correction on photography G03B27/725; picture communication systems H04N1/46)} · CPC title

• G03G9/10

  characterised by carrier particles · CPC title

• G03G9/08797

  characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature · CPC title

• G03G13/08

  using a solid developer, e.g. powder developer · CPC title