Two-component developer, replenishing developer, and image-forming method
First Claim
1. A two-component developer, comprising:
- a yellow toner having yellow toner particles each having at least a binder resin and a colorant, and an external additive; and
a magnetic carrier,(a) wherein the yellow toner has the following characteristics;
(i) when a concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and an absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the following expression (5)
6.00<
A422/Cy<
14.40
(5);
(ii) a lightness L* and a chroma C* of the yellow toner determined in a powder state satisfy relationships of 85.0≦
L*≦
95.0 and 100.0≦
C*≦
115.0; and
(iii) an absolute value for a triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less, and(b) wherein the magnetic carrier comprises at least magnetic core particles and a resin component;
a packed bulk density ρ
1 (g/cm3) and a true density ρ
2 (g/cm3) of the magnetic core particles of the magnetic carrier satisfy relationships of 0.80≦
ρ
1≦
2.40 and 0.20≦
ρ
1/ρ
2≦
0.42;
a specific resistance of each of the magnetic core particles of the magnetic carrier is 1.0×
103 Ω
·
cm or more and 5.0×
107 Ω
·
cm or less; and
when a 50% particle diameter on a volume basis of the magnetic carrier is represented by D50, an average breaking strength P1 (MPa) of the magnetic carrier having a particle diameter of D50−
5 μ
m or more and D50+5 μ
m or less and an average breaking strength P2 (MPa) of the magnetic carrier having a particle diameter of 10 μ
m or more and less than 20 μ
m satisfy a relationship of 0.50≦
P2/P1≦
1.10.
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Accused Products
Abstract
A two-component developer containing a yellow toner and a magnetic carrier, wherein the yellow toner has the characteristics: (i) when the concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and the absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the relationship of 6.00<A422/Cy<14.40; (ii) the lightness L* and chroma C* of the yellow toner determined in a powder state satisfy the relationships of 85.0≦L*≦95.0 and 100.0≦C*≦115.0; and (iii) the absolute value for the triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.
-
Citations
10 Claims
-
1. A two-component developer, comprising:
-
a yellow toner having yellow toner particles each having at least a binder resin and a colorant, and an external additive; and a magnetic carrier, (a) wherein the yellow toner has the following characteristics; (i) when a concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and an absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the following expression (5)
6.00<
A422/Cy<
14.40
(5);(ii) a lightness L* and a chroma C* of the yellow toner determined in a powder state satisfy relationships of 85.0≦
L*≦
95.0 and 100.0≦
C*≦
115.0; and(iii) an absolute value for a triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less, and (b) wherein the magnetic carrier comprises at least magnetic core particles and a resin component; a packed bulk density ρ
1 (g/cm3) and a true density ρ
2 (g/cm3) of the magnetic core particles of the magnetic carrier satisfy relationships of 0.80≦
ρ
1≦
2.40 and 0.20≦
ρ
1/ρ
2≦
0.42;a specific resistance of each of the magnetic core particles of the magnetic carrier is 1.0×
103 Ω
·
cm or more and 5.0×
107 Ω
·
cm or less; andwhen a 50% particle diameter on a volume basis of the magnetic carrier is represented by D50, an average breaking strength P1 (MPa) of the magnetic carrier having a particle diameter of D50−
5 μ
m or more and D50+5 μ
m or less and an average breaking strength P2 (MPa) of the magnetic carrier having a particle diameter of 10 μ
m or more and less than 20 μ
m satisfy a relationship of 0.50≦
P2/P1≦
1.10. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A replenishing developer for use in a two-component developing method including:
- performing development while replenishing a developing device with the replenishing developer; and
discharging an excess magnetic carrier in the developing device from the developing device, comprising;a yellow toner having yellow toner particles each having at least a binder resin and a colorant, and an external additive; and a magnetic carrier, the replenishing developer being a two-component developer containing the yellow toner at a mass ratio of 2 parts by mass or more and 50 parts by mass or less with respect to 1 part by mass of the magnetic carrier, (a) wherein the yellow toner has the following characteristics; (i) when a concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and an absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the following expression (5)
6.00<
A422/Cy<
14.40
(5);(ii) a lightness L* and a chroma C* of the yellow toner determined in a powder state satisfy relationships of 85.0≦
L*≦
95.0 and 100.0≦
C*≦
115.0; and(iii) an absolute value for a triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less, and (b) wherein the magnetic carrier comprises at least magnetic core particles and a resin component; a packed bulk density ρ
1 (g/cm3) and a true density ρ
2 (g/cm3) of the magnetic core particles of the magnetic carrier satisfy relationships of 0.80≦
ρ
1≦
2.40 and 0.20≦
ρ
1/ρ
2≦
0.42;a specific resistance of each of the magnetic core particles of the magnetic carrier is 1.0×
103 Ω
·
cm or more and 5.0×
107 Ω
·
cm or less; andwhen a 50% particle diameter on a volume basis of the magnetic carrier is represented by D50, an average breaking strength P1 (MPa) of the magnetic carrier having a particle diameter of D50−
5 μ
m or more and D50+5 μ
m or less and an average breaking strength P2 (MPa) of the magnetic carrier having a particle diameter of 10 μ
m or more and less than 20 μ
m satisfy a relationship of 0.50≦
P2/P1≦
1.10.
- performing development while replenishing a developing device with the replenishing developer; and
-
8. An image-forming method, comprising:
-
a charging step of charging an electrostatic latent image bearing member; a latent image forming step of forming an electrostatic latent image on the electrostatic latent image bearing member charged in the charging step; a developing step of developing the electrostatic latent image formed on the image bearing member with a two-component developer containing a yellow toner having yellow toner particles each having at least a binder resin and a colorant, and an external additive, and a magnetic carrier to form a yellow toner image; a transferring step of transferring the cyan toner image on the electrostatic latent image bearing member onto a transfer material through or without through an intermediate transfer body; and a fixing step of fixing the yellow toner image to the transfer material, wherein; a laid-on level of the yellow toner of a monochromatic solid image portion having an image density of 1.5 in the yellow toner image unfixed to be formed on the transfer material is in a range of 0.10 mg/cm2 or more to 0.50 mg/cm2 or less; and (a) the yellow toner has the following characteristics; (i) when a concentration of the yellow toner in a solution of the yellow toner in chloroform is represented by Cy (mg/ml) and an absorbance of the solution at a wavelength of 422 nm is represented by A422, a relationship between Cy and A422 satisfies the following expression (5)
6.00<
A422/Cy<
14.40
(5);(ii) a lightness L* and a chroma C* of the yellow toner determined in a powder state satisfy relationships of 85.0≦
L*≦
95.0 and 100.0≦
C*≦
115.0; and(iii) an absolute value for a triboelectric charge quantity of the yellow toner measured by a two-component method using the yellow toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less, and (b) wherein the magnetic carrier comprises at least magnetic core particles and a resin component; a packed bulk density ρ
1 (g/cm3) and a true density ρ
2 (g/cm3) of the magnetic core particles of the magnetic carrier satisfy relationships of 0.80≦
ρ
1≦
2.40 and 0.20≦
ρ
1/ρ
2≦
0.42;a specific resistance of each of the magnetic core particles of the magnetic carrier is 1.0×
103 Ω
·
cm or more and 5.0×
107 Ω
·
cm or less; andwhen a 50% particle diameter on a volume basis of the magnetic carrier is represented by D50, an average breaking strength P1 (MPa) of the magnetic carrier having a particle diameter of D50−
5 μ
m or more and D50+5 μ
m or less and an average breaking strength P2 (MPa) of the magnetic carrier having a particle diameter of 10 μ
m or more and less than 20 μ
m satisfy a relationship of 0.50≦
P2/P1≦
1.10. - View Dependent Claims (9, 10)
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Specification