Toner kit, deep-color cyan toner, pale-color cyan toner, and image forming method

• US 7,381,509 B2
• Filed: 08/28/2007
• Issued: 06/03/2008
• Est. Priority Date: 11/19/2003
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ikeda, Takeshi, Ayaki, Yasukazu, Ishida, Tomohito, Itoh, Nobuyuki
• Primary Examiner(s): Goodrow; John L
• Application Number:
  US11/846,308
• Publication Number:
  US 20080050670A1
• Time in Patent Office: 280 Days
• Field of Search: 430/45.55, 430/107.1, 430/111.4
• US Class Current: 430/45.55
• CPC Class Codes: G03G 9/0821 characterised by physical parameters magnetic parameters G03G9/083
• CPC Class Codes: G03G 9/09 Colouring agents for toner particles
• CPC Class Codes: G03G 9/0906 Organic dyes
• CPC Class Codes: G03G 9/0926 characterised by physical or chemical properties

Abstract

The present invention provides: a toner kit having a deep toner and a pale toner which are separated from each other, wherein: the deep toner and the pale toner satisfy prescribed conditions for an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness; the pale toner and the deep toner to be used in the toner kit; and a method for forming an image using the toner kit. Thus, the present invention can form a high quality image, while suppressing graininess and roughness over the areas covering from the low density area to the high density area.

Claims

1. A toner kit comprising:

a pale cyan toner comprising at least a binder resin and a colorant; and

a deep cyan toner comprising at least a binder resin and a colorant,

the pale cyan toner and the deep cyan toner being separated from each other, wherein;

when a toner image fixed on plain paper is expressed by an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness,

in a fixed image of the pale cyan toner, the pale cyan toner has a value of a* (a*_C1) in a range of −

30 to −

19 when b* is −

20 and a value of a* (a*_C2) in a range of −

45 to −

29 when b* is −

30;

in a fixed image of the deep cyan toner, the deep cyan toner has a value of a* (a*_C3) in a range of −

29 to −

19 when b* is −

20 and a value of a* (a*_C4) in a range of −

43 to −

29 when b* is −

30; and

the relationships of a*_C1≦

a*_C3 and a*_C2≦

a*_C4 are satisfied.

2. The toner kit according to claim 1, wherein:

a difference between a*_C1 and a*_C3 (a*_C1−

a*_C3) is in a range of −

8 to −

1; and

a difference between a*_C2 and a*_C4 (a*_C2−

a*_C4) is in a range of −

12 to −

1.

3. The toner kit according to claim 1, wherein:

the difference between a*_C1 and a*_C3 (a*_C1−

a*_C3) is in a range of −

7 to −

1; and

the difference between a*_C2 and a*_C4 (a*_C2−

a*_C4) is in a range of −

10 to −

1.

4. The toner kit according to claim 1, wherein:

the a*_C1 is in a range of −

26 to −

19;

the a*_C2 is in a range of −

39 to −

29;

the a*_C3 is in a range of −

23 to −

19; and

the a*_C4 is in a range of −

35 to −

29.

5. The toner kit according to claim 1, wherein:

the pale cyan toner has a value of L* in a range of 85 to 90 when c* represented by the following equation is 30; and

the deep cyan toner has the value of L* in a range of 74 to 84 when c* is 30.

c*=√

{square root over (a*²+b*²)}.

6. The toner kit according to claim 1, wherein:

a hue angle (H*_C1) of the pale cyan toner is in a range of 214 to 229°

; and

a hue angle(H*_C2) of the deep cyan toner is in a range of 216 to 237°

.

7. The toner kit according to claim 6, wherein:

a difference between H*_C1 and H*_C2 (H*_C2−

H*_C1) is in a range of 0.1 to 22°

.

8. The toner kit according to claim 6, wherein:

a difference between H*_C1 and H*_C2 (H*_C2−

H*_C1) is in a range of 1 to 17°

.

9. The toner kit according to claim 1, wherein:

the colorant of each of the pale cyan toner and the deep cyan toner contains a pigment.

10. The toner kit according to claim 1, wherein:

the pale cyan toner comprises 0.4 to 1.5% by mass of the colorant with respect to a total amount of the toner; and

the deep cyan toner comprises 2.5 to 8.5% by mass of the colorant with respect to the total amount of the toner.

11. The toner kit according to claim 1, wherein:

the deep cyan toner provides an optical density in a range of 1.5 to 2.5 for a solid image having a toner amount of 1 mg/cm² on paper; and

the pale toner provides an optical density in a range of 0.82 to 1.35 for the solid image having the toner amount of 1 mg/cm² on paper.

12. The toner kit according to claim 1, wherein:

the pale cyan toner and the deep cyan toner each have a charge control agent; and

a ratio of a content of the charge control agent in the pale cyan toner to a content of the charge control agent in the deep cyan toner is in a range of 0.60 to 0.95.

13. The toner kit according to claim 1, wherein:

a weight average particle diameter of the pale cyan toner is in a range of 3 to 9 μ

m; and

a weight average particle diameter of the deep cyan toner is in the range of 3 to 9 μ

m.

14. The toner kit according to claim 1, wherein a ratio of a weight average particle diameter of the pale cyan particle to a weight average particle diameter of the deep cyan particle is in a range of 1.05 to 1.40.

15. The toner kit according to claim 1, wherein:

each of the pale cyan toner and the deep cyan toner comprises inorganic fine powders selected from a group consisting of titania, alumina, silica, and double oxides thereof; and

a ratio of a specific surface area of the pale cyan toner to a specific surface area of the deep cyan toner is in a range of 0.60 to 0.95.

16. The toner kit according to claim 1, further comprising:

a pale color two-component developer comprising at least the pale cyan toner and a carrier; and

a deep color two-component developer comprising at least the deep cyan toner and a carrier.

17. The toner kit according to claim 1, further comprising:

a pale color one-component developer comprising the pale cyan toner; and

a deep color one-component developer comprising the deep cyan toner.

18. A toner kit comprising:

a pale cyan toner comprising at least a binder resin and a colorant; and

a deep cyan toner comprising at least a binder resin and a colorant,

a pale magenta toner comprising at least a binder resin and a colorant; and

a deep magenta toner comprising at least a binder resin and a colorant,

the pale cyan toner, the deep cyan toner, the pale magenta toner, and the deep magenta toner being separated from each other, wherein;

when a toner image fixed on plain paper is expressed by an L*a*b* color coordinate system where a* represents a hue in the red-green direction, b* represents a hue in the yellow-blue direction, and L* represents a lightness,

in a fixed image of the cyan toner, the cyan toner has a value of a* (a*_C1) in a range of −

30 to −

19 when b* is −

20 and a value of a* (a*_C2) in a range of −

45 to −

29 when b* is −

30;

in a fixed image of the deep cyan toner, the deep cyan toner has a value of a* (a*_C3) in a range of −

29 to −

19 when b* is −

20 and a value of a* (a*_C4) in a range of −

43 to −

29 when b* is −

30;

the relationships of a*_C1≦

a*_C3 and a*_C2≦

a*_C4 are satisfied;

in a fixed image of the pale magenta toner, the pale magenta toner has a value of b* (b*_M1) in a range of −

18 to 0 when a* is 20 and value of b* (b*_M2) in a range of −

26 to 0 when a* is 30; and

in a fixed image of the deep magenta toner, the deep magenta toner has a value of b* (b*_M3) in a range of −

16 to 2 when a* is 20 and value of b* (b*_M4) in a range of −

24 to 3 when a* is 30, a difference between b*_M1 and b*_M3 (b*_M1−

b*_M3) in a range of −

8 to −

1, and a difference between b*_M2 and b*_M4 (b*_M2−

b*_M4) in a range of −

12 to −

1.