Two-component developer, replenishing developer, and image-forming method
First Claim
1. A two-component developer, comprising:
- a magenta toner having magenta toner particles each having at least a binder resin and a colorant, and an external additive; and
a magnetic carrier,(a) wherein the magenta toner has the following characteristics;
(i) when a concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and an absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the following expression (3)
2.00<
A538/Cm<
6.55
(3);
(ii) a lightness L* and a chroma C* of the magenta toner determined in a powder state satisfy relationships of 35.0≦
L*≦
45.0 and 60.0≦
C*≦
72.0; and
(iii) an absolute value for a triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta 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.
1 Assignment
0 Petitions
Accused Products
Abstract
A two-component developer containing a magenta toner and a magnetic carrier, wherein the magenta toner has the characteristics: (i) when the concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and the absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the relationship of 2.00<A538/Cm<6.55; (ii) the lightness L* and chroma C* of the magenta toner determined in a powder state satisfy the relationships of 35≦L*≦45 and 60≦C*≦72; and (iii) the absolute value for the triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less.
61 Citations
11 Claims
-
1. A two-component developer, comprising:
-
a magenta toner having magenta toner particles each having at least a binder resin and a colorant, and an external additive; and a magnetic carrier, (a) wherein the magenta toner has the following characteristics; (i) when a concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and an absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the following expression (3)
2.00<
A538/Cm<
6.55
(3);(ii) a lightness L* and a chroma C* of the magenta toner determined in a powder state satisfy relationships of 35.0≦
L*≦
45.0 and 60.0≦
C*≦
72.0; and(iii) an absolute value for a triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta 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 magenta toner having magenta 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 magenta 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 magenta toner has the following characteristics; (i) when a concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and an absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the following expression (3)
2.00<
A538/Cm<
6.55
(3);(ii) a lightness L* and a chroma C* of the magenta toner determined in a powder state satisfy relationships of 35.0≦
L*≦
45.0 and 60.0≦
C*≦
720 and(iii) an absolute value for a triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta 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 0.80ρ
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; an electrostatic 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 electrostatic latent image bearing member with a two-component developer containing a magenta toner having magenta toner particles each having at least a binder resin and a colorant, and an external additive, and a magnetic carrier to form a magenta toner image; a transferring step of transferring the magenta 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 magenta toner image to the transfer material, wherein; a laid-on level of the magenta toner of a monochromatic solid image portion having an image density of 1.5 in the magenta 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 magenta toner has the following characteristics; (i) when a concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and an absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the following expression (3)
2.00<
A538/Cm<
6.55
(3);(ii) a lightness L* and a chroma C* of the magenta toner determined in a powder state satisfy relationships of 35.0≦
L*≦
45.0 and 60.0≦
C*≦
72.0 and(iii) an absolute value for a triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta 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 0.20ρ
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)
-
-
11. A full-color image-forming method, comprising:
-
forming a first electrostatic latent image on an electrostatic latent image bearing member; developing the electrostatic latent image with a first two-component developer selected from the group consisting of a two-component developer a containing a cyan toner having cyan toner particles each having at least a binder resin and a colorant, and an external additive, and a magnetic carrier, a two-component developer b containing a magenta toner having magenta toner particles each having at least a binder resin and a colorant, and an external additive, and a magnetic carrier, and a two-component developer c 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 first toner image on the electrostatic latent image bearing member; transferring the first toner image onto a transfer material through or without through an intermediate transfer body; forming a second electrostatic latent image on the electrostatic latent image bearing member; developing the electrostatic latent image with a second two-component developer except the first two-component developer selected from the group consisting of the two-component developer a, the two-component developer b, and the two-component developer c to form a second toner image on the electrostatic latent image bearing member; transferring the second toner image onto the transfer material through or without through the intermediate transfer body; forming a third electrostatic latent image on the electrostatic latent image bearing member; developing the electrostatic latent image with a third two-component developer except the first two-component developer and the second two-component developer selected from the group consisting of the two-component developer a, the two-component developer b, and the two-component developer c to form a third toner image on the electrostatic latent image bearing member; transferring the third toner image onto the transfer material through or without through the intermediate transfer body; and fixing the first to third toner images on the transfer material under heat to form a full-color image on the transfer material, wherein; a laid-on level of each of the cyan toner, the magenta toner, and the yellow toner of a monochromatic solid image portion having an image density of 1.5 and formed on the transfer material is in a range of 0.10 mg/cm2 or more to 0.50 mg/cm2 or less; (a) the cyan toner has the following characteristics; (i) when a concentration of the cyan toner in a solution of the cyan toner in chloroform is represented by Cc (mg/ml) and an absorbance of the solution at a wavelength of 712 nm is represented by A712, a relationship between Cc and A712 satisfies the following expression (1)
2.00<
A712/Cc<
8.15
(1);(ii) a lightness L* and a chroma C* of the cyan toner determined in a powder state satisfy relationships of 25.0≦
L*≦
40.0 and 50.0≦
C*≦
60.0; and(iii) an absolute value for a triboelectric charge quantity of the cyan toner measured by a two-component method using the cyan toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less; (b) the magenta toner has the following characteristics; (i) when a concentration of the magenta toner in a solution of the magenta toner in chloroform is represented by Cm (mg/ml) and an absorbance of the solution at a wavelength of 538 nm is represented by A538, a relationship between Cm and A538 satisfies the following expression (3)
2.00<
A538/Cm<
6.55
(3);(ii) a lightness L* and a chroma C* of the magenta toner determined in a powder state satisfy relationships of 35.0≦
L*≦
45.0 and 60.0≦
C*≦
72.0 and(iii) an absolute value for a triboelectric charge quantity of the magenta toner measured by a two-component method using the magenta toner and the magnetic carrier is 50 mC/kg or more and 120 mC/kg or less; and (c) 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 (d) 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.
-
Specification