Developing unit and electrophotographic image forming apparatus
First Claim
Patent Images
1. A developing unit, comprising at least:
- a toner of (1);
a developing roller of (2); and
a toner regulating member for controlling a toner amount on a surface of the developing roller;
(1) a toner,comprising;
toner particles each containing at least a binder resin, a coloring agent, and a wax component; and
an inorganic fine powder, wherein;
whena displacement amount (μ
m) obtained when a load is applied to one particle of the toner at a temperature of Y°
C. and at a loading rate of 9.8×
10−
5 N/sec, and the load is reached at a maximum load of 2.94×
10−
4 N, is defined as a displacement amount X2(Y),a displacement amount (μ
m) obtained when, after the load has reached the maximum load, the particle is left to stand under the maximum load for 0.1 second, is defined as a maximum displacement amount X3(Y),a displacement amount (μ
m) obtained when, after the standing for 0.1 second, the load is reduced at an unloading rate of 9.8×
10−
5 N/sec, and then the load is reached at 0 N, is defined as a displacement amount X4(Y),a difference between the maximum displacement amount X3(Y) and the displacement amount X4(Y), is defined as an elastic displacement amount (X3(Y)−
X4(Y)), anda percentage of the elastic displacement amount (X3(Y)−
X4(Y)) to the maximum displacement amount X3(Y), {(X3(Y)−
X4(Y))/X3(Y)}×
100, is defined as Z(Y) (%),Z(25), Z(Y) at the temperature Y is 25°
C., satisfies a relationship of 40≦
Z(25)≦
80, andZ(50), Z(Y) at the temperature Y is 50°
C., satisfies a relationship of 10≦
Z(50)≦
55;
in a load-displacement curve of which a displacement amount of the toner versus the load thereon at a temperature of 25°
C. is plotted, when a gradient of the load-displacement curve from an origin to a point at which the load reaches the maximum load, is defined as R(25) (N/μ
m), 2.94×
10−
4/displacement amount X2(25), R(25) satisfies a relationship of 0.49×
10−
3≦
R(25)≦
1.70×
10−
3;
having a glass transition temperature (TgA) of 40°
C. or more and 60°
C. or less, and a peak temperature (P1) of a maximum endothermic peak of 70°
C. or more and 110°
C. or less; and
satisfying a relationship of 15°
C.≦
(P1−
TgA)≦
70°
C.; and
(2) a developing roller, comprising;
a mandrel;
an elastic layer formed on a periphery of the mandrel; and
a surface layer containing a urethane resin, the surface layer coating a peripheral surface of the elastic layer, whereinthe urethane resin has, between two adjacent urethane bonds,a structure represented by the following structural formula (a), andone or both of structures selected from a structure represented by the following structural formula (b) and a structure represented by the following structural formula (c)
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Abstract
Provided are a developing unit alleviating fogging occurrence and an electrophotographic image forming apparatus providing images over long periods. The developing unit includes at least a toner of (1) and a developing roller of (2). (1) When a displacement amount when a load is applied at Y° C. and 9.8×10−5 N/sec to 2.94×10−4 N is X2(Y), a displacement amount when the toner is left to stand for 0.1 second is X3(Y), a displacement amount when the load is reduced at 9.8×10−5 N/sec to 0N is X4(Y), and percentage of (X3(Y)−X4(Y)) to X3(Y) is Z(Y), 40≦Z(25)≦80 and 10≦Z(50)≦55 are satisfied; when a gradient from the origin to the maximum load in the load-displacement curve at 25° C. is R(25), 0.49×10−3≦R(25)≦1.70×10−3 is satisfied; the toner has glass transition temperature TgA (40° C.-60° C.) and maximum endothermic peak temperature P1 (70° C.-110° C.), 15° C.≦(P1−TgA)≦70° C. is satisfied. (2) The developing roller includes a surface layer containing a urethane resin having structure (a), and one or both structures (b)-(c).
32 Citations
5 Claims
-
1. A developing unit, comprising at least:
-
a toner of (1); a developing roller of (2); and a toner regulating member for controlling a toner amount on a surface of the developing roller; (1) a toner, comprising; toner particles each containing at least a binder resin, a coloring agent, and a wax component; and an inorganic fine powder, wherein; when a displacement amount (μ
m) obtained when a load is applied to one particle of the toner at a temperature of Y°
C. and at a loading rate of 9.8×
10−
5 N/sec, and the load is reached at a maximum load of 2.94×
10−
4 N, is defined as a displacement amount X2(Y),a displacement amount (μ
m) obtained when, after the load has reached the maximum load, the particle is left to stand under the maximum load for 0.1 second, is defined as a maximum displacement amount X3(Y),a displacement amount (μ
m) obtained when, after the standing for 0.1 second, the load is reduced at an unloading rate of 9.8×
10−
5 N/sec, and then the load is reached at 0 N, is defined as a displacement amount X4(Y),a difference between the maximum displacement amount X3(Y) and the displacement amount X4(Y), is defined as an elastic displacement amount (X3(Y)−
X4(Y)), anda percentage of the elastic displacement amount (X3(Y)−
X4(Y)) to the maximum displacement amount X3(Y), {(X3(Y)−
X4(Y))/X3(Y)}×
100, is defined as Z(Y) (%),Z(25), Z(Y) at the temperature Y is 25°
C., satisfies a relationship of 40≦
Z(25)≦
80, andZ(50), Z(Y) at the temperature Y is 50°
C., satisfies a relationship of 10≦
Z(50)≦
55;in a load-displacement curve of which a displacement amount of the toner versus the load thereon at a temperature of 25°
C. is plotted, when a gradient of the load-displacement curve from an origin to a point at which the load reaches the maximum load, is defined as R(25) (N/μ
m), 2.94×
10−
4/displacement amount X2(25), R(25) satisfies a relationship of 0.49×
10−
3≦
R(25)≦
1.70×
10−
3;having a glass transition temperature (TgA) of 40°
C. or more and 60°
C. or less, and a peak temperature (P1) of a maximum endothermic peak of 70°
C. or more and 110°
C. or less; andsatisfying a relationship of 15°
C.≦
(P1−
TgA)≦
70°
C.; and(2) a developing roller, comprising; a mandrel; an elastic layer formed on a periphery of the mandrel; and a surface layer containing a urethane resin, the surface layer coating a peripheral surface of the elastic layer, wherein the urethane resin has, between two adjacent urethane bonds, a structure represented by the following structural formula (a), and one or both of structures selected from a structure represented by the following structural formula (b) and a structure represented by the following structural formula (c) - View Dependent Claims (2, 3, 4, 5)
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Specification
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Current AssigneeCanon Ayutthaya Limited (Canon Inc.)
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Original AssigneeCanon Ayutthaya Limited (Canon Inc.)
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InventorsKawamura, Kunimasa, Nakamura, Minoru, Urushihara, Shohei, Yamada, Masaki, Katsuta, Yasushi
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Primary Examiner(s)Chen, Sophia S
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Application NumberUS14/075,410Publication NumberTime in Patent Office354 DaysField of Search399/252, 399/286, 399/279, 430/108.1, 430/120.1, 430/123.5US Class Current399/252CPC Class CodesG03G 15/0806 on a donor element, e.g. be...G03G 15/0818 characterised by the struct...G03G 9/00 DevelopersG03G 9/0821 characterised by physical p...G03G 9/08795 characterised by their chem...G03G 9/08797 characterised by their phys...
