JP2002372831A - Image forming method and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a full color image forming method and a full color image forming device by which sufficient image density is obtained even in the case of low potential development, and high image quality and high durability are satisfied. SOLUTION: In this tandem type image forming method, an a-Si photoreceptor whose diameter is 20 to 80 mm is used as a photoreceptor, surface potential in a developing area is set to 300 to 450 V as an absolute value, and a two-component type developing method in which the minimum space between the photoreceptor and a developing sleeve is set to 350 to 800 μm is used. The circumferential speed of the developing sleeve is made 1.1 to 4.0 times as high as that of the photoreceptor. Then, non-magnetic toner to be positively electrified whose particle size is 4 to 10 μm, whose tinting strength is 1.0 to 1.8 and which is set so that a difference between the maximum value and the minimum value of the tinting strength of YMC is <=0.5 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus for use in a laser beam color printer, a color copying machine, and the like. The present invention relates to an image forming method and apparatus.

[0002]

2. Description of the Related Art Photoreceptors are broadly classified into two types: organic and inorganic. [Organic photoconductor (OPC)] In recent years, various organic photoconductive materials have been developed as photoconductive materials for electrophotographic photoconductors. In particular, a function-separated type photoconductor in which a charge generation layer and a charge transport layer are laminated is already in practical use. And installed in copiers and laser beam printers.

However, one of the major drawbacks of these photoconductors is that their durability is generally low. The durability is roughly classified into the durability of electrophotographic physical properties such as sensitivity, residual potential, charging ability, and image blur, and the mechanical durability such as abrasion of the photoreceptor surface due to rubbing and scratches. Has become a major factor in determining the lifespan.

[0004] Among them, durability of electrophotographic physical properties, particularly, image blur, relates to ozone generated from a corona charger,
It is known that the cause is that the charge transporting substance contained in the photoreceptor surface layer is deteriorated by an active substance such as NOx.

It is known that mechanical durability is caused by physical contact of paper, a cleaning member such as a blade / roller, toner, or the like with the photosensitive layer to cause rubbing.

In order to improve the durability of electrophotographic physical properties, it is important to use a charge transporting substance which is hardly deteriorated by an active substance such as ozone or NOx, and it is necessary to select a charge transporting substance having a high oxidation potential. It has been known. Also, in order to increase mechanical durability, the surface should be rubbed by paper or a cleaning member to reduce friction. It is important to improve the releasability, and it is known to mix a lubricant such as a fluororesin powder, a fluorinated graphite, and a polyolefin resin powder in the surface layer. However, when the wear becomes extremely small, hygroscopic substances generated by active substances such as ozone and NOx accumulate on the photoreceptor surface,
As a result, there is a problem that the surface resistance is lowered, the surface charges are moved in the horizontal direction, and the image is blurred (image deletion).

[Inorganic photoconductor: Amorphous silicon photoconductor (a-Si)] In electrophotography, a photoconductive material for forming a photosensitive layer in the photoconductor has high sensitivity,
High N ratio [photocurrent (Ip) / dark current (Id)], having an absorption spectrum suitable for the spectral characteristics of the irradiating electromagnetic wave, quick photoresponse, having a desired dark resistance value, Are required to be harmless to the human body. In particular, in the case of a photoconductor for an image forming apparatus that is incorporated in an image forming apparatus used in an office as an office machine, the above-described non-pollution during use is important. Hydrogenated amorphous silicon (hereinafter, referred to as “a-Si:
H "). For example, Japanese Patent Publication No. 60-350
No. 59 describes an application as a photoreceptor for an image forming apparatus.

In general, a photosensitive member for an image forming apparatus using a-Si: H is prepared by heating a conductive support to 50 to 400 ° C., and applying a vacuum deposition method, a sputtering method, A photoconductive layer made of a-Si is formed by a film forming method such as a plating method, a thermal CVD method, a photo CVD method, and a plasma CVD method (hereinafter, referred to as “PCVD method”). Among them, the PCVD method, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on a support has been put to practical use.

Japanese Patent Application Laid-Open No. 54-83746 discloses a conductive support and an a-Si containing a halogen atom as a constituent element (hereinafter referred to as "a-Si: X").
2. Description of the Related Art A photoconductor for an image forming apparatus including a photoconductive layer has been proposed. In this publication, one halogen atom is added to a-Si.
It is stated that when the content is in the range of 40 to 40 atomic%, heat resistance is high and good electrical and optical characteristics can be obtained as a photoconductive layer of a photoconductor for an image forming apparatus.

Japanese Patent Application Laid-Open No. 57-11556 discloses that a photoconductive member having a photoconductive layer composed of an a-Si deposited film has an electrical property such as a dark resistance value, a photosensitivity, and a photoresponsiveness. In order to improve the use environment characteristics such as optical and photoconductive properties and moisture resistance, as well as the stability over time, silicon atoms and carbon are deposited on a photoconductive layer composed of an amorphous material based on silicon atoms. A technique of providing a surface layer made of a non-photoconductive amorphous material containing atoms is described.

Further, Japanese Patent Application Laid-Open No. Sho 60-67951 describes a technique relating to a photoconductor in which a light-transmitting insulating overcoat layer containing amorphous silicon, carbon, oxygen and fluorine is laminated. 62-16816
No. 1 describes a technique using an amorphous material containing silicon atoms, carbon atoms, and 41 to 70 atomic% of hydrogen atoms as constituent elements as a surface layer.

Furthermore, in JP-A-57-158650, hydrogen containing 10 to 40 atomic%, 0.2 absorption coefficient ratio of the absorption peak of 2100 cm ^-1 and 2000 cm ^-1 in the infrared absorption spectrum It is described that a photosensitive member for an image forming apparatus having high sensitivity and high resistance can be obtained by using a-Si: H of 1.7 for the photoconductive layer.

On the other hand, Japanese Patent Application Laid-Open No. 60-95551 discloses that in order to improve the image quality of an amorphous silicon photoreceptor, the temperature near the photoreceptor surface is maintained at 30 to 40.degree. By performing such an image forming process, there is disclosed a technique for preventing a reduction in surface resistance due to the adsorption of moisture on the surface of a photoreceptor and an image flow (high-humidity flow) generated thereby.

[0014] These techniques have improved the electrical, optical, photoconductive and operating environment characteristics of the photoreceptor for an image forming apparatus, and accordingly the image quality.

[0015]

In recent years, the expansion of office networks and the diversification of information have spread, and printers,
Copiers are also becoming more colorized. In particular, with the increase in the amount of information, there is a demand for further speeding up of full-color printers and full-color copying machines.

Conventionally, an OPC (organic photoreceptor) has been widely used as a photoreceptor as a latent image carrier for a full-color copying machine. However, since the OPC has low hardness and is abraded, the frequency of replacement of the photoconductor increases with the speed of the machine. For this reason, with regard to the study of a high-speed copying machine using OPC, studies have been made to increase the hardness to prevent abrasion, and to cope with an increase in speed.

On the other hand, in an image forming apparatus using an a-Si photoreceptor, since the hardness is high, the frequency of exchanging the photoreceptor due to abrasion of the drum can be reduced. In addition, the dot reproducibility is good, and when combined with a magnetic toner, there is an advantage that a high-quality copy can be obtained.

However, there are some problems in converting a-Si to a digital color copier.

The a-Si photoreceptor has a problem that image deletion occurs under a high temperature and high humidity condition and a surface potential fluctuates due to a temperature fluctuation. In order to solve this, a drum heater is inserted inside the photoconductor to control the temperature to be constant.

On the other hand, since the toner for a color copying machine has a configuration in which toners of a plurality of colors are fixed in a multiplex manner, the softening point of the toner is set low. When a toner having a high softening point is used, the color mixing in the fixing device deteriorates, and a problem occurs in color reproducibility. When such a low softening point toner is used in a high-speed full-color copying machine, the mechanical share is large in the cleaner section, the contact section between the transfer section roller and the photoconductor, and the heat generation amount of the photoconductor is large. And the toner easily melts on the photoreceptor. In particular, when the temperature of the photoconductor is controlled by the drum heater, the temperature is more remarkable, and the problem of fusion of the toner to the photoconductor and the problem of filming in which the toner resin is uniformly deposited on the photoconductor surface occur. . Therefore, even when the a-Si photoconductor is used, maintenance of the photoconductor is required, and the advantage of long life of the a-Si cannot be sufficiently obtained.

Therefore, when an a-Si photosensitive member is mounted on a color machine, it is necessary to develop a toner capable of reducing fusion and filming to the photosensitive member and achieving color reproducibility at the time of fixing. Have been.

When a photoconductor is mounted on a tandem type full-color copying machine, the size of the photoconductor is limited by the space of the apparatus. As a result, the size of each device that performs the functions of charging, exposure, development, transfer, cleaning, and charge removal is limited. In particular, when the width of the charging device is limited, a sufficient surface potential (charge potential) on the photoconductor cannot be obtained, and as a result, a high-density image cannot be obtained. Therefore, a toner and a developing method that can obtain a sufficient image density even in low potential development are required. In addition, even in a system that achieves such low potential development, it is necessary to establish a toner and a developing method that provide high-quality images with excellent color reproducibility.

Another advantage of using the a-Si photoreceptor in a full-color machine is that the quality of an image is improved. The a-Si photoreceptor has high reproducibility of the dot level generated by image exposure and can obtain a high quality image. However, if an attempt is made to reduce the diameter of the color toner, the amount of charge of the toner tends to increase and the amount of toner to be developed generally tends to decrease, which is disadvantageous for low potential development with an a-Si photosensitive member. Therefore, there is an urgent need to develop a high-definition, high-quality image forming method and an image forming apparatus exhibiting high developability.

[0024]

SUMMARY OF THE INVENTION The present invention relates to the a-S
According to the present invention, an a-Si photosensitive member is used in a tandem-type full-color copying machine to form an image by a two-component developing method. As a result, it has been found that a full-color image forming method and apparatus capable of achieving high definition and high speed can be realized.

That is, according to the present invention, the first toner image formed by the first image forming unit is transferred to a transfer material,
The second toner image formed by the first image forming unit is transferred to a transfer material having the first toner image, and the third toner image formed by the third image forming unit is transferred by the first and second toners. The image is transferred to a transfer material having an image, and the fourth toner image formed by the fourth image forming unit is transferred to the first and second image forming units.
Transferred to a transfer material having second and third toner images,
Image formation in which a transfer material having the first, second, third and fourth toner images is transported to a heat and pressure fixing unit, and heat and pressure is fixed to form a full-color image or a multi-color image on the transfer material. In the method, (A) the first image formation in the first image forming unit is performed by: (i) a first charging step of charging an amorphous silicon or a first photoconductor having an amorphous silicon layer; At least one exposure step, a first development step using a first development sleeve,
(Ii) The first photosensitive member has a diameter of 20 to 80 mm, and after the developing area of the photosensitive member facing the developing sleeve is charged to an absolute value of 300 to 450 V in the first charging step, the first exposure is performed. An electrostatic image is formed on the first photoconductor by the exposure in the step, and (iii) in the first developing step,
A two-component developer including a first toner and a first magnetic carrier forms a magnetic brush on the first developing sleeve;
(Iv) the first photoconductor and the first developing sleeve are installed such that the minimum gap is 350 to 800 μm;
(V) While the first developing sleeve is rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the first photoconductor, the first electrostatic charge image is formed by the magnetic brush of the two-component developer. Develop the first
Is formed on the first photoconductor, and (B) the second image formation in the second image forming unit is performed by (i) charging the second photoconductor having amorphous silicon or an amorphous silicon layer. (Ii) the second photoconductor has a diameter of 20 to 80 mm, and includes a second charging step, a second exposure step, and a second developing step using a second developing sleeve. After the developing region of the photoconductor facing the developing sleeve is charged to an absolute value of 300 to 450 V in the process, an electrostatic image is formed on the second photoconductor by exposure in the second exposure process, and (iii) In the developing step 2, the two-component developer containing the second toner and the second magnetic carrier forms a magnetic brush on the second developing sleeve, and (iv) the second photosensitive member and the second developing means. Minimum gap between sleeve and 350-800μ m, and (v) a two-component developer while rotating the second developing sleeve at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the second photoconductor. Developing the second electrostatic charge image with the magnetic brush to form a second toner image on the second photoconductor, and (C) forming a third image in the third image forming unit by (i) Amorphous silicon or third with amorphous silicon layer
A third charging step of charging the photoconductor, a third exposure step,
The method further includes at least a third developing step using a third developing sleeve, (ii) the third photosensitive member has a diameter of 20 to 80 mm, and the developing region of the photosensitive member facing the developing sleeve in the third charging step is After being charged to an absolute value of 300 to 450 V, an electrostatic image is formed on the third photoconductor by exposure in the third exposure step. (Iii) In the third development step, the third toner and the third toner The two-component developer containing the magnetic carrier forms a magnetic brush on the third developing sleeve, and (iv) a minimum gap between the third photosensitive member and the third developing sleeve is 350 to 800 μm. (V) the third developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the third photosensitive member while being rotated by a magnetic brush of a two-component developer. Develop the third electrostatic image to form a third toner image (D) fourth image formation in the fourth image forming unit formed on the photoreceptor;
At least a fourth charging step of charging the photoconductor, a fourth exposure step, and a fourth development step using a fourth developing sleeve. (Ii) The fourth photoconductor has a diameter of 20 to 80 m.
m, the developing area of the photoconductor facing the developing sleeve is charged to an absolute value of 300 to 450 V in the fourth charging step, and then an electrostatic image is formed on the fourth photoconductor by the fourth exposure step (Iii) in the fourth developing step,
A two-component developer including a fourth toner and a fourth magnetic carrier forming a magnetic brush on the fourth developing sleeve;
(Iv) the fourth photosensitive member and the fourth developing sleeve are provided such that the minimum gap is 350 to 800 μm;
(V) The fourth developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the fourth photoreceptor, and the fourth electrostatic charge image is formed by the magnetic brush of the two-component developer. Develop the 4th
(E) the first toner, the second toner, the third toner and the fourth toner have different color tones from each other, and It is selected from the group consisting of yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and non-magnetic black toner, and (a) non-magnetic yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and non-magnetic black toner are positively charged And the weight average particle diameter of each toner is 4.
(B) the 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm, and (c) the transfer power of each color is determined by the amount of unfixed toner on the transfer material. When (M / S) is M / S = 0.5 mg / cm ² , the image density after one-time fixing is defined as D0.5, the yellow toner coloring power is D0.5Y, and the magenta toner coloring power is D0.5Y. D
0.5M, the coloring power of the cyan toner is D0.5C, and the coloring power of the black toner is D0.5Bk.
Y, D0.5M, D0.5C, and D0.5Bk are 1.0 to 1.8, respectively, and the coloring power of the toner that exhibits the maximum coloring power among the three colors of yellow, magenta, and cyan is D0.
5max, the coloring power of the one showing the minimum coloring power is D0.5min
When the difference between D0.5max and D0.5min is 0 to 0.
5 is an image forming method.

Further, according to the present invention, the first toner image formed by the first image forming unit is transferred to a transfer material, and the second toner image is transferred to the transfer material.
The second toner image formed by the first image forming unit is transferred to a transfer material having the first toner image, and the third toner image formed by the third image forming unit is transferred by the first and second toners. The image is transferred to a transfer material having an image, and the fourth toner image formed by the fourth image forming unit is transferred to the first and second image forming units.
Transferred to a transfer material having second and third toner images,
Image formation in which a transfer material having the first, second, third and fourth toner images is transported to a heat and pressure fixing unit, and heat and pressure is fixed to form a full-color image or a multi-color image on the transfer material. The apparatus comprises: (A) a first image forming unit, (i) a first photosensitive member having amorphous silicon or an amorphous silicon layer, a first charging unit, a first charging unit,
(Ii) the first photoconductor has a diameter of 20 to 80 mm, and is opposed to the developing sleeve by the first charging means. The developing area of the photoconductor is 300 in absolute value.
After being charged to about 450 V, an electrostatic image is formed on the first photosensitive member by exposure by the first exposure means, and (iii)
The first developing means has a two-component developer containing a first toner and a first magnetic carrier, the two-component developer forming a magnetic brush on the first developing sleeve, (I
v) The first photosensitive member and the first developing sleeve are set so that the minimum gap is 350 to 800 μm.
(V) While the first developing sleeve is rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the first photoconductor, the first electrostatic charge image is formed by the magnetic brush of the two-component developer. Develop the first
(B) The second image forming unit comprises (i) a second photosensitive member having amorphous silicon or an amorphous silicon layer, a second charging unit, Exposure means, a second developing sleeve having a second developing sleeve.
(Ii) the second photoconductor has a diameter of 20 to 80 mm, and the developing area of the photoconductor opposed to the developing sleeve by the second charging means has an absolute value of 300 to 450 V After being charged, an electrostatic image is formed on the second photoconductor by exposure by the second exposure means,
(Iii) The second developing means has a two-component developer containing a second toner and a second magnetic carrier, and the two-component developer forms a magnetic brush on the second developing sleeve. (Iv) the second photosensitive member and the second developing sleeve are disposed so that the minimum gap is 350 to 800 μm, and (v) the second developing sleeve is the second photosensitive member. The second electrostatic image is developed by a magnetic brush of a two-component developer while rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of And (C) a third image forming unit comprising: (i) a third photosensitive member having amorphous silicon or an amorphous silicon layer, a third charging unit, a third exposing unit, and a third exposing unit. Third with developing sleeve
(Ii) the third photosensitive member has a diameter of 20 to 80 mm, and the developing area of the photosensitive member facing the developing sleeve by the third charging means is 300 to 450 V in absolute value. After being charged, an electrostatic image is formed on the third photoconductor by exposure by a third exposure unit,
(Iii) The third developing means has a two-component developer containing a third toner and a third magnetic carrier, and the two-component developer forms a magnetic brush on the third developing sleeve. (Iv) the third photosensitive member and the third developing sleeve are disposed so that the minimum gap is 350 to 800 μm; and (v) the third developing sleeve is the third photosensitive member. The third electrostatic image is developed with a magnetic brush of a two-component developer while rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of And (D) a fourth image forming unit comprising: (i) a fourth photosensitive member having amorphous silicon or an amorphous silicon layer, a fourth charging unit, a fourth exposing unit, and a fourth unit. 4th with developing sleeve
(Ii) the fourth photoreceptor has a diameter of 20 to 80 mm, and the fourth charging unit causes the developing area of the photoreceptor facing the developing sleeve to have an absolute value of 300 to 80 mm. After being charged to 450 V, an electrostatic image is formed on the fourth photosensitive member by the fourth exposure means, and (iii)
The fourth developing means has a two-component developer including a fourth toner and a fourth magnetic carrier, the two-component developer forming a magnetic brush on the fourth developing sleeve, (I
v) The fourth photosensitive member and the fourth developing sleeve are installed such that the minimum gap is 350 to 800 µm.
(V) The fourth developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the fourth photoreceptor, and the fourth electrostatic charge image is formed by the magnetic brush of the two-component developer. Develop the 4th
(E) the first toner, the second toner, the third toner and the fourth toner have different color tones from each other, and It is selected from the group consisting of yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and non-magnetic black toner, and (a) non-magnetic yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and non-magnetic black toner are positively charged And the weight average particle diameter of each toner is 4.
(B) the 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm, and (c) the transfer power of each color is determined by the amount of unfixed toner on the transfer material. When (M / S) is M / S = 0.5 mg / cm ² , the image density after one-time fixing is defined as D0.5, the yellow toner coloring power is D0.5Y, and the magenta toner coloring power is D0.5Y. D
0.5M, the coloring power of the cyan toner is D0.5C, and the coloring power of the black toner is D0.5Bk.
Y, D0.5M, D0.5C, and D0.5Bk are 1.0 to 1.8, respectively, and the coloring power of the toner that exhibits the maximum coloring power among the three colors of yellow, magenta, and cyan is D.
0.5max, the coloring power of the one exhibiting the minimum coloring power was D0.
If 5 min, the difference between D0.5max and D0.5min is 0
０．５0.5.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming method of the present invention will be described below with reference to the drawings, but this does not limit the present invention in any way.

FIG. 1 is a schematic configuration diagram of one embodiment of an electrophotographic full-color machine, which is an image forming apparatus for implementing the image forming method of the present invention.

In FIG. 1, ABCD stations indicate image forming units for forming yellow, magenta, cyan, and black images of a full-color image, respectively, but the color order of the stations does not matter at all. In the following description, for example, if the primary charging device 21 is provided, A
Primary charging devices 21A, 2B at each BCD station
1B, 1C, 21D.

In each station, image formation is performed as follows.

First, a photosensitive drum 4 serving as a photosensitive member is rotatably provided, and the photosensitive drum 4 is uniformly charged by a primary charging device 21 serving as a charging means. A light emitting element 22 exposes an information signal to form an electrostatic latent image, and is developed by a developing device 9 which is a developing unit having a developing sleeve to form a toner image.
Next, the toner image is transferred to the transfer paper 24 conveyed by the transfer paper conveyance sheet 27 by the transfer charging device 23.

On the transfer paper 24, a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are sequentially transferred and superimposed at each station.

The transfer paper 24 on which the toner images of the four colors are stacked is mixed and fixed by heat and pressure by a fixing device 25 which is a heating and pressing fixing means, and is discharged out of the device as a full-color image.

The transfer residual toner on the photosensitive drum 4 is removed by the cleaning device 26.

The present invention provides a tandem-type full-color copying machine using an amorphous silicon or a photosensitive member having an amorphous silicon layer. By using a tandem-type system, a high-speed full-color system that can be reduced in size without increasing the moving speed (process speed) of the photoconductor can be achieved.

Since there is no potential difference at each developing device position (developing area) due to dark decay as compared with the fixed developing system of one photosensitive drum, density control can be easily performed. In addition, large diameter a-
It is possible to eliminate problems such as a decrease in density and unevenness due to retransfer when Si is used, and characteristic unevenness which is a problem in manufacturing a large-diameter drum. <1> Image Forming Unit in the Present Invention An image forming apparatus using the image forming method of the present invention is a tandem type color image forming apparatus having four image forming units as shown in FIG. In a two-component developing system including a magnetic carrier, the diameter is 20 to
Using a photoreceptor having 80 mm of amorphous silicon or an amorphous silicon layer (hereinafter referred to as “a-Si photoreceptor”), a developing region is charged to 300 to 450 V in a charging step, and is used as a two-component developer toner. A non-magnetic toner having a weight average particle diameter of 4.0 to 10.0 μm, and the coloring power of the toner is determined by measuring the unfixed toner amount (M / S) on the transfer material.
When M / S = 0.5 mg / cm ² , the image density of each color (D0.5Y, D0.5M, D
0.5C, D0.5Bk) is 1.0 to 1.8, and the difference between the maximum value and the minimum value of D0.5 for the three colors of yellow, magenta, and cyan is 0 to 0.5. It was found that by using a carrier having a 50% volume average particle diameter of 10 to 80 μm as a carrier, it was possible to obtain a high-quality image with high image density and excellent color reproduction.

When the diameter of the photosensitive member is smaller than 20 mm,
The charging width is limited. Therefore, the surface potential (charging potential) on the photoreceptor, considering the charging device capability and high pressure leak,
It is difficult to obtain a sufficient charging potential, and it is difficult to obtain a high-quality image when developing a high-speed full-color copying machine. In addition, since the nip with the developing sleeve is reduced, the developing area is reduced, and the density is easily reduced.

Conversely, when the diameter of the photoreceptor is larger than 80 mm, the charging potential is sufficiently obtained and the density is sufficiently obtained. However, at the time of transfer, the toner on the transfer material formed by the previous image forming unit is transferred. Part of the image or the toner is likely to be retransferred to the photoconductor. For this reason, toner consumption increases, warpage during transfer is likely to occur. In particular, when an image is formed in four stations, the image in the first station is retransferred in the second, third, and fourth stations, so that it is difficult to maintain the image density and to remove the image. Further, when a large-diameter photosensitive member is used, there is a disadvantage that the apparatus becomes large. More preferable diameter of the photoreceptor is 30 to 80 mm
It is.

Regarding the charging of the photoreceptor, if the surface potential in the developing region of the photoreceptor facing the developing sleeve is smaller than 300 V, a sufficient image density cannot be obtained. 4
When the voltage is higher than 50 V, the two-component developing method is not preferable because it is easy to pick up a defect on the photoconductor such as uneven density due to potential unevenness of the photoconductor and a drum ghost, thereby easily causing an image defect.

In the present invention, the photosensitive drum and the developing sleeve are set so that the minimum gap is 350 to 800 μm, and the developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the photosensitive member. By performing development using a magnetic brush of a two-component developer, toner fusion to the photoreceptor surface does not occur, a sufficient image density is obtained, toner deterioration is effective, and dot It has been found that an image with good reproducibility can be stably obtained.

The minimum gap between the photosensitive member and the developing sleeve (SD
When the gap is smaller than 350 μm, the share in the gap increases, and as a result, fusion occurs easily on the photoconductor. On the other hand, if it is larger than 800 μm, the toner flying distance becomes longer, so that the toner hardly reaches the photoconductor, and a sufficient image density cannot be obtained.

When the developing is performed by a magnetic brush composed of a two-component developer while rotating the developing sleeve at a peripheral speed smaller than 1.1 times the peripheral speed of the photosensitive member, it is difficult to supply toner required for the development. Therefore, a sufficient image density cannot be obtained. When the developing sleeve is rotated at a peripheral speed greater than 4.0 times the peripheral speed of the photoreceptor, the share in the developing device becomes large, toner deterioration becomes severe, and the density reduction after continuous use tends to be remarkable. is there. A more preferable peripheral speed of the developing sleeve with respect to the photoconductor is 1.5 to 3.0 times. (A) Photoconductor Having Amorphous Silicon or Amorphous Silicon Layer in the Present Invention Next, the a-Si photoconductor used in the image forming unit in the present invention will be described below.

FIG. 2 is a schematic diagram for explaining the layer structure of the a-Si photosensitive member according to the present invention.

The a-Si photosensitive member 1100 shown in FIG.
In the figure, a photosensitive layer 1102 is provided on a conductive support 1101 for a photosensitive member. The photosensitive layer 1102 is a
-Photoconductive layer 11 made of Si: H, X and having photoconductivity
03.

FIG. 2B is a schematic configuration diagram for explaining another layer configuration of the photosensitive member for an image forming apparatus of the present invention. Photoconductor 1100 for an image forming apparatus shown in FIG.
In the figure, a photosensitive layer 1102 is provided on a conductive support 1101 for a photosensitive member. The photosensitive layer 1102 is a
-Photoconductive layer 11 made of Si: H, X and having photoconductivity
03 and an amorphous silicon-based surface layer 1104.

FIG. 2C is a schematic structural view for explaining another layer constitution of the photosensitive member for an image forming apparatus of the present invention. Photoconductor 1100 for an image forming apparatus shown in FIG.
In the figure, a photosensitive layer 1102 is provided on a conductive support 1101 for a photosensitive member. The photosensitive layer 1102 is a
-Photoconductive layer 11 made of Si: H, X and having photoconductivity
0.3, an amorphous silicon-based surface layer 1104,
And an amorphous silicon-based charge injection blocking layer 1105.

FIG. 2D is a schematic structural view for explaining still another layer constitution of the photosensitive member for an image forming apparatus of the present invention. Photoreceptor 110 for an image forming apparatus shown in FIG.
0 is on the conductive support 1101 for the photoreceptor,
A photosensitive layer 1102 is provided. The photosensitive layer 1102 is composed of a charge generation layer 1106 and a charge transport layer 1107 made of a-Si: H, X constituting the photoconductive layer 1103, and an amorphous silicon-based surface layer 1104.

A photoreceptor for an image forming apparatus using a-Si: H is generally prepared by heating a conductive support to 50 to 400 ° C. and depositing the conductive support on the support by vacuum deposition, sputtering, ion A photoconductive layer made of a-Si is formed by a film forming method such as a plating method, a thermal CVD method, a photo CVD method, and a plasma CVD method (hereinafter, referred to as “PCVD method”). Among them, the PCVD method, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on a support is preferable. <Conductive Support> The conductive support used in the present invention may be either conductive or electrically insulating. Examples of the conductive support include well-known metals such as Al and Fe, and alloys thereof, for example, stainless steel.
Further, a support in which at least the surface on the side on which the photosensitive layer is formed of an electrically insulating support such as a synthetic resin film or sheet, glass, ceramic or the like can be used.

The conductive support 1 used in the present invention
The shape of 101 may be a cylindrical or plate-like endless belt having a smooth surface or an uneven surface.

In particular, when image recording is performed using coherent light such as laser light, the number of charged carriers must be reduced in order to more effectively eliminate image defects caused by so-called interference fringe patterns appearing in a visible image. Irregularities may be provided on the surface of the conductive support 1101 within a substantially non-existent range. Support 1
The unevenness provided on the surface of 101 is disclosed in JP-A-60-168.
156, JP-A-60-178457, JP-A-60-225854 and the like.

Another method for more effectively eliminating image defects due to interference fringe patterns when coherent light such as laser light is used is as follows: unevenness due to a plurality of spherical trace depressions on the surface of the conductive support 1101. A shape may be provided. That is, the surface of the conductive support 1101 is
It has finer irregularities than the resolution required for 00, and the irregularities are caused by a plurality of spherical trace depressions. The unevenness due to the plurality of spherical trace depressions provided on the surface of the conductive support 1101 can be created by a known method described in JP-A-61-231561.

As still another method for more effectively eliminating image defects due to interference fringe patterns when using coherent light such as laser light, the photosensitive layer 1102 or the layer 11 may be used.
An interference prevention layer such as a light absorption layer or a region may be provided below 02. <Photoconductive layer> In the present invention, a part of the photosensitive layer 1102 is formed on the conductive support 1101 and, if necessary, on the undercoat layer (not shown) in order to effectively achieve the object. The photoconductive layer 1103, which is preferably formed, can be formed by a vacuum deposition film forming method by appropriately setting numerical conditions of film forming parameters so as to obtain desired characteristics. Specifically, for example, a glow discharge method (low-frequency CVD
Method, AC discharge CVD method such as high-frequency CVD method or microwave CVD method, or DC discharge CVD method), sputtering, vacuum deposition, ion plating, light CVD, thermal CVD, etc. It can be formed by a method. These thin film deposition methods are appropriately selected and adopted depending on factors such as manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for a photoconductor for an image forming apparatus to be manufactured. The glow discharge method is preferable because it is relatively easy to control the conditions for manufacturing a photosensitive member for an image forming apparatus having characteristics.

In order to form the photoconductive layer 1103 by the glow discharge method, a source gas for supplying Si which can supply silicon atoms (Si) and a source gas for supplying H which can supply hydrogen atoms (H) are basically used. Is introduced in a desired gas state into a reaction vessel capable of reducing the pressure inside the reaction vessel, and / or a glow discharge is generated in the reaction vessel. A-S on a predetermined support 1101 previously set at a predetermined position.
i: A layer composed of H and X may be formed.

In the present invention, it is preferable that the photoconductive layer 1103 contains a hydrogen atom and / or a halogen atom, which compensates for dangling bonds of silicon atoms and improves the layer quality. This is because they are indispensable for improving the properties and charge retention characteristics. Therefore, the content of hydrogen atoms or halogen atoms, or the sum of hydrogen atoms and halogen atoms is 10 to 30 atomic% with respect to the sum of silicon atoms and hydrogen atoms and / or halogen atoms.
More preferably, the content is 15 to 25 atomic%.

As a substance which can be a Si supply gas used in the present invention, a gaseous or gasifiable silicon hydride (silanes) can be used effectively. SiH ₄ and Si ₂ H ₆ are preferable in terms of easiness and high Si supply efficiency.

Then, hydrogen atoms are structurally introduced into the formed photoconductive layer 1103 so that the introduction ratio of hydrogen atoms can be more easily controlled, and a film characteristic that achieves the object of the present invention is obtained. Therefore, it is preferable to form a layer by mixing a desired amount of a gas of a silicon compound containing H ₂ and / or He or a hydrogen atom with these gases. Also,
Each gas is not limited to a single species, and a plurality of species may be mixed at a predetermined mixture ratio. Also useful as a source gas for supplying a halogen atom used in the present invention are a gaseous or gasizable halogen compound such as a halogen gas, a halide, an interhalogen compound containing a halogen, a silane derivative substituted with a halogen, and the like. Are preferred. Further, a gaseous or gasifiable silicon hydride compound containing a halogen atom, which contains a silicon atom and a halogen atom as constituent elements, can also be mentioned as an effective compound.

In order to control the amount of hydrogen atoms and / or halogen atoms contained in the photoconductive layer 1103, for example, the temperature of the support 1101, a raw material used to contain hydrogen atoms and / or halogen atoms What is necessary is just to control the amount of the substance introduced into the reaction vessel, the discharge power and the like.

In the present invention, it is preferable that the photoconductive layer 1103 contains atoms for controlling conductivity as necessary. The atoms that control the conductivity are the photoconductive layer 1103.
It may be contained in a uniformly distributed state in the inside, or there may be a part contained in a non-uniform distribution state in the layer thickness direction.

Examples of the atoms for controlling the conductivity include so-called impurities in the semiconductor field.
As is well known, an atom belonging to Group 3b of the Periodic Table that gives p-type conduction characteristics (Group 3b atom) or an atom belonging to Group 5b of the Periodic Table that gives n-type conduction characteristics (Group 5b atom) can be used. .

Further, these raw materials for introducing atoms for controlling conductivity may be diluted with H ₂ and / or He if necessary.

Further, in the present invention, the photoconductive layer 110
It is also effective that 3 contains a carbon atom and / or an oxygen atom and / or a nitrogen atom. The carbon atoms and / or oxygen atoms and / or nitrogen atoms may be evenly and uniformly contained in the photoconductive layer, or may have an uneven distribution such that the content changes in the thickness direction of the photoconductive layer. May be provided.

In the present invention, the thickness of the photoconductive layer 1103 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economical effects.
It is desirable that the thickness be 0 to 50 μm, more preferably 23 to 45 μm, and most preferably 25 to 40 μm.

In order to achieve the object of the present invention and to form the photoconductive layer 1103 having desired film characteristics, the mixing ratio of the gas for supplying Si and the diluent gas, the gas pressure in the reaction vessel, the discharge power, The temperature of the conductive support can be appropriately set.

The above-mentioned conditions are not usually determined independently and separately. Rather, the optimum values are determined based on mutual and organic relationships in order to form a photoreceptor having desired characteristics. Is desirable. <Surface Layer> In the present invention, it is preferable to further form a surface layer 1104 on the photoconductive layer 1103 formed on the conductive support 1101 as described above. This surface layer 1104 is provided in order to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability. Surface layer 1104
Represents an amorphous silicon (a-Si) based material, for example, a hydrogen atom (H) and / or a halogen atom (X)
And further contains a carbon atom, amorphous silicon (hereinafter referred to as "a-SiC: H, X"), a hydrogen atom (H) and / or a halogen atom (X), and further contains an oxygen atom. Amorphous silicon (hereinafter referred to as “a
-SiO: H, X "), amorphous silicon containing a hydrogen atom (H) and / or a halogen atom (X) and further containing a nitrogen atom (hereinafter referred to as" a-SiN:
H, X "), a hydrogen atom (H) and / or a halogen atom (X), and further a carbon atom, an oxygen atom,
A material such as amorphous silicon containing at least one nitrogen atom (hereinafter referred to as “a-SiCON: H, X”) is preferably used.

In the present invention, in order to effectively achieve the object, the surface layer 1104 is formed by appropriately setting the numerical conditions of film forming parameters by a vacuum deposited film forming method so as to obtain desired characteristics. Is done. Specifically, for example, a glow discharge method (an AC discharge CVD method such as a low-frequency CVD method, a high-frequency CVD method or a microwave CVD method, or a DC discharge CVD method), a sputtering method, a vacuum deposition method, an ion plating method, It can be formed by various thin film deposition methods such as a photo CVD method and a thermal CVD method. These thin film deposition methods are appropriately selected and adopted depending on factors such as manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the photoconductor for an image forming apparatus to be manufactured. It is preferable to use the same deposition method as that for the photoconductive layer from the viewpoint of productivity.

For example, a-Si
In order to form the surface layer 1104 composed of C: H, X, a source gas for supplying Si that can supply silicon atoms (Si) and a C for supplying C that can supply carbon atoms (C) are basically used. A source gas and a source gas for supplying H capable of supplying hydrogen atoms (H) or / and X capable of supplying halogen atoms (X)
A source gas for supply is introduced in a desired gas state into a reaction vessel capable of reducing the pressure inside, and a glow discharge is generated in the reaction vessel to form a photoconductive layer 1103 previously set at a predetermined position. A-SiC:
What is necessary is just to form the layer which consists of H and X.

When the surface layer is composed mainly of a-SiC, the amount of carbon is preferably in the range of 30 to 90% based on the sum of silicon atoms and carbon atoms.

Further, in the present invention, it is necessary that the surface layer 1104 contains hydrogen atoms and / or halogen atoms, which compensates for dangling bonds of silicon atoms and improves the quality of the layer, especially the optical quality. It is indispensable to improve the conductivity characteristics and the charge retention characteristics. In general, the hydrogen content is desirably 30 to 70 atomic%, preferably 35 to 65 atomic%, and most preferably 40 to 60 atomic%, based on the total amount of the constituent atoms. In addition, the content of fluorine atoms is usually 0.01 to 15 atomic%, preferably 0.1 to 15 atomic%.
It is desirable that the content be 1 to 10 atomic%, optimally 0.6 to 4 atomic%. Defects in the surface layer (mainly dangling bonds of silicon atoms and carbon atoms) are caused by, for example, deterioration of charging characteristics due to injection of electric charge from the free surface to the photoconductive layer, and surface structure in a use environment such as high humidity. Changes in the charging characteristics due to the change in charge, and furthermore, an afterimage phenomenon at the time of repeated use due to charges being injected into the surface layer by the photoconductive layer during corona charging or light irradiation, and charges being trapped by defects in the surface layer. It is known that, for example, the generation of the toner adversely affects the characteristics as a photoconductor for an image forming apparatus.

By controlling the hydrogen content in the surface layer to 30 atomic% or more, the defects in the surface layer are greatly reduced, and the electrical characteristics and the high-speed continuous usability can be improved. On the other hand, when the hydrogen content in the surface layer exceeds 70 atomic%, the hardness of the surface layer decreases, and the durability decreases.

Further, by controlling the fluorine content in the surface layer to a range of 0.01 atomic% or more, it is possible to more effectively achieve the generation of the bond between silicon atoms and carbon atoms in the surface layer. Become. Further, as a function of fluorine atoms in the surface layer, it is possible to effectively prevent the bond between silicon atoms and carbon atoms from being broken due to damage such as corona. on the other hand,
When the fluorine content in the surface layer exceeds 15 atomic%, the effect of generating the bond between silicon atoms and carbon atoms in the surface layer and the effect of preventing the breaking of the bond between silicon atoms and carbon atoms are hardly recognized. Furthermore, since excess fluorine atoms hinder the mobility of carriers in the surface layer, remnant potential and image memory are remarkably observed.

The fluorine content and the hydrogen content in the surface layer are H
_It can be controlled by the flow rate of the _two gases, the temperature of the conductive support, the discharge power, the gas pressure, and the like.

The layer thickness of the surface layer 1104 in the present invention is usually 0.01 to 3 μm, preferably 0.05 to 2 μm.
m, and most preferably 0.1 to 1 μm. If the layer thickness is less than 0.01 μm, the surface layer is lost due to abrasion during use of the photoreceptor, and the
If it exceeds m, a decrease in electrophotographic characteristics such as an increase in residual potential is observed.

The surface layer 1104 according to the present invention is carefully formed so that its required properties are provided as desired. That is, a substance containing Si, C and / or N and / or O, H and / or X as a constituent element takes a form from crystalline to amorphous depending on its forming condition, and is electrically conductive. Since the properties between to semiconductive and insulating properties, and the properties between photoconductive properties and non-photoconductive properties, respectively, in the present invention,
The formation conditions are strictly selected as desired so that a compound having desired properties according to the purpose is formed.

For example, in order to provide the surface layer 1104 mainly for the purpose of improving the pressure resistance, the surface layer 1104 is made of a non-single-crystal material having a remarkable electric insulating property in a use environment.

When the main purpose is to improve the continuous repetitive use characteristics and the use environment characteristics, the above-mentioned degree of electrical insulation is alleviated to a certain extent, and the non-conductive layer has a certain sensitivity to the irradiated light. Formed as a single crystal material.

Further, in order to prevent the image flow due to the low resistance of the surface layer 1104 or to prevent the influence of the residual potential, etc., and to improve the charging efficiency, the resistance value of the layer is appropriately adjusted when forming the layer. It is preferable to control it.

Further, in the present invention, it is also possible to provide a blocking layer (lower surface layer) having a lower content of carbon atoms, oxygen atoms and nitrogen atoms than the surface layer between the photoconductive layer and the surface layer. It is effective to further improve the characteristics such as performance.

A region may be provided between the surface layer 1104 and the photoconductive layer 1103 so that the content of carbon atoms and / or oxygen atoms and / or nitrogen atoms changes so as to decrease toward the photoconductive layer 1103. good. Thereby, the adhesion between the surface layer and the photoconductive layer can be improved, and the influence of interference due to light reflection at the interface can be further reduced. <Charge Injection Prevention Layer> In the photoreceptor for an image forming apparatus of the present invention, a charge injection prevention layer having a function of preventing charge injection from the conductive support side between the conductive support and the photoconductive layer. Is more effective. That is, the charge injection blocking layer has a function of preventing charge from being injected from the conductive support side to the photoconductive layer side when the photosensitive layer is subjected to a charging treatment of a fixed polarity on its free surface. Such a function is not exhibited when it is subjected to a polarity charging process, which is a so-called polarity dependency. In order to provide such a function, it is preferable that the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer.

The atoms for controlling the conductivity contained in the layer may be uniformly distributed in the layer uniformly, or may be uniformly distributed in the thickness direction of the layer, Some portions may be contained in a state of being uniformly distributed. When the distribution concentration is non-uniform, it is preferable that the compound be contained so as to be distributed more on the support side.

However, in any case, it is preferable that the compound is uniformly distributed and uniformly distributed in the in-plane direction parallel to the surface of the support from the viewpoint of making the characteristics in the in-plane direction uniform.

As the atoms for controlling the conductivity contained in the charge injection blocking layer, there can be mentioned so-called impurities in the field of semiconductors, and the 3b group atoms in the periodic table giving the p-type conductivity or the n-type conductivity. To give the periodic table No. 5
Group b atoms can be used.

In the present invention, the content of atoms for controlling conductivity contained in the charge injection blocking layer is appropriately determined as desired so that the object of the present invention can be effectively achieved.

Further, the charge injection blocking layer contains carbon atoms,
By containing at least one of a nitrogen atom and an oxygen atom, the adhesion to another layer provided in direct contact with the charge injection blocking layer can be further improved.

The carbon atoms, nitrogen atoms, or oxygen atoms contained in the layer may be uniformly distributed throughout the layer, or may be evenly distributed in the thickness direction of the layer. Some portions may be contained in a non-uniformly distributed state. However, in any case, it is preferable that the compound is uniformly distributed and uniformly distributed in the in-plane direction parallel to the surface of the conductive support from the viewpoint of making the characteristics in the in-plane direction uniform.

The content of carbon atoms and / or nitrogen atoms and / or oxygen atoms contained in the entire layer region of the charge injection blocking layer in the present invention is appropriately determined in consideration of charging characteristics and stability during fabrication. In addition, the hydrogen atoms and / or halogen atoms contained in the charge injection blocking layer in the present invention compensate for dangling bonds existing in the layer, and are effective in improving the film quality.

In the present invention, the thickness of the charge injection blocking layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. Most preferably, it is 0.5 to 3 μm.

In the present invention, to form the charge injection blocking layer, a vacuum deposition method similar to the above-described method of forming the photoconductive layer is employed.

In addition, in the photoreceptor for an image forming apparatus of the present invention, the conductive support 11 of the photosensitive layer 1102
It is desirable to have a layer region containing at least aluminum atoms, silicon atoms, hydrogen atoms and / or halogen atoms in a non-uniform distribution state in the layer thickness direction on the 01 side.

Further, in the photoreceptor for an image forming apparatus of the present invention, in order to further improve the adhesion between the conductive support 1101 and the photoconductive layer 1103 or the charge injection blocking layer 1105, For example, Si ₃ N ₄ , SiO ₂ , Si
O or a silicon atom as a base, a hydrogen atom and / or
Alternatively, an adhesion layer formed of an amorphous material containing a halogen atom and a carbon atom and / or an oxygen atom and / or a nitrogen atom may be provided.

Further, as described above, a light absorbing layer may be provided to prevent the occurrence of interference patterns due to the light reflected from the support. These charge injection blocking layers, photoconductive layers, surface layers, and the like are combined to produce a positive or negative photoconductor. (B) Method of Manufacturing Photoreceptor in the Present Invention The above-described photoreceptor is prepared using a known CVD apparatus.

FIG. 3 shows a high-frequency plasma C using the RF band.
1 shows an example of a VD method (referred to as “RF-PCVD”) apparatus. This apparatus is roughly classified into a deposition apparatus (2100),
Source gas supply device (2200), reaction vessel (211)
1) It comprises an exhaust device (not shown) for reducing the pressure inside. The reaction vessel (2) in the deposition apparatus (2100)
111), a cylindrical support (2112), a heater for heating the support (2113), a raw material gas introduction pipe (2114) are provided, and a high frequency matching box (2115) is further provided.
Is connected.

The source gas supply device (2200) is made of SiH
₄ , H ₂ , CH ₄ , B ₂ H ₆ , PH _{3 and} other source gas cylinders (2221-2226) and valves (2231-223)
6, 2241 to 2246, 2251 to 2256) and a mass flow controller (2211 to 2216), and a cylinder for each raw material gas is supplied via a valve (2260) to a gas introduction pipe (211) in a reaction vessel (2111).
4) is connected.

FIG. 4 shows an example of an apparatus of a high frequency plasma CVD method using VHF band (referred to as "VHF-PCVD"). This apparatus is a deposition apparatus (210
0) is replaced with the deposition apparatus (3100) shown in FIG.
This is an example in which the manufacturing apparatus is an F-PCVD method. This apparatus is roughly classified into a reaction vessel (3111) having a vacuum-tight structure and capable of reducing pressure, and a source gas supply apparatus (220).
0), and an exhaust device (not shown) for reducing the pressure inside the reaction vessel. Reaction vessel (3111)
A cylindrical support (3112), a heater for heating the conductive support (3113), and electrodes are provided therein, and a high-frequency matching box (3120) is further connected to the electrodes. In addition, an exhaust pipe (312) is provided in the reaction vessel (3111).
1) is connected to a diffusion pump (not shown). The space (3130) surrounded by the cylindrical conductive support (3112) forms a discharge space. (C) Developing Device in the Present Invention The developing device used in the image forming unit in the present invention is a two-component developing system constituting a magnetic brush, and there is no particular limitation as long as the minimum gap between the developing sleeve and the photoconductor is 350 to 800 μm. Instead, an ordinary developing device can be used.

FIG. 5 shows an example of a developing device used in the image forming unit.

In FIG. 5, a developing device 9 arranged opposite to the photosensitive drum 4 includes a developing container 8, a developing sleeve 3 as a developer conveying means, and a developer return member 1 for regulating the developer reservoir 5. And a blade 2 as a member for controlling the height of the developer. The inside of the developing device 9 is divided into a developing chamber (first chamber) 13 and a stirring chamber (second chamber) 14 by a partition 6 extending in the vertical direction, and the upper part of the partition 6 is open. The developing chamber 13 and the stirring chamber 14 contain a two-component developer containing a non-magnetic color toner and a magnetic carrier, and the excess two-component developer in the developing chamber 13 is supplied to the stirring chamber 14 side. Collected.

In the developing chamber 13 and the stirring chamber 14, first and second stirring screws 11 and 12 are disposed, respectively.

The developing chamber 13 of the developing device 9 includes the photosensitive drum 4
The developing sleeve 3 is rotatably arranged so as to be partially exposed in the opening. The developing sleeve 3 is made of a non-magnetic material, rotates during the developing operation in the direction of the arrow in the figure, and has a magnet (magnet roller) 10 as a magnetic field generating means fixed inside. The developing sleeve 3 carries and transports the layer of the two-component developer whose layer thickness is regulated by the blade 2, and supplies the developer to the photosensitive drum 4 in a developing area facing the photosensitive drum 4 to develop the latent image. In order to improve the developing efficiency, a developing bias voltage in which, for example, a DC voltage is superimposed on an AC voltage is applied to the developing sleeve 3 from the power supply 15.

The developing device 9 holds the two-component developer supplied to the surface of the developing sleeve 3 by the stirring screws 11 and 12 in the state of a magnetic brush by the magnetic force of the magnet roller 10 with the above configuration. The developing sleeve 3
(Developing area) facing the photosensitive drum 4 based on the rotation of
And the developer return member 1 and the blade 2
Thus, the amount of the developer conveyed to the developing area by cutting the magnetic brush is appropriately maintained.

More specifically, the magnet roller 10 of such a developing device has a five-pole structure, and the developer stirred by the developing chamber stirring screw 11 is supplied to the transfer magnetic pole (pumping pole) N2 for pumping. The developer is constrained by the magnetic force and is conveyed to the developer reservoir 5 by the rotation of the developing sleeve 3. The amount of the developer is regulated by the developer return member 1, and is sufficiently constrained by a transport magnetic pole (cut pole) S2 having a certain or more magnetic flux density to form a magnetic brush in order to restrict the stable developer. Is transported. Next, the magnetic brush is cut off by the blade, that is, the spike height regulating member 2, so that the amount of the developer is adjusted appropriately, and the developer is conveyed by the conveying magnetic pole N1. Further, a bias voltage in which a direct current and / or an alternating electric field is superimposed is applied to the developing sleeve 3 via a bias power supply 15 provided on the image forming apparatus main body side at the developing pole S1, and the toner on the developing sleeve 3 is transferred to the photosensitive drum. 4 is moved to the electrostatic latent image side, and the electrostatic latent image is visualized as a toner image.
As the exposure device used in the image forming unit, a usual one may be used. That is, when a positively charged toner is used, a latent image is formed by image exposure when a positively charged photoreceptor is used, and a latent image is formed by back scan exposure when a negatively charged photoreceptor is used. As shown in FIG. 1, the image forming unit preferably further includes a transfer unit such as a transfer charging device, a cleaning device, and the like, and these may be those used in a normal image forming device. <2> Two-Component Developer in the Present Invention Next, the developer and the toner in the present invention will be described.

The toner (yellow toner,
Magenta toner, cyan toner, black toner)
Positively charged non-magnetic toner, used together with a magnetic carrier as a two-component developer.

Further, in the present invention, the coloring power of each toner is determined by the amount of unfixed toner (M / S) on the transfer material.
When the density is 0.5 mg / cm ² , the image density (D0.5Y, D0.5M, D0.5C, D
0.5Bk) becomes 1.0 to 1.8, and yellow,
A toner in which the difference between the maximum value and the minimum value of D0.5 for the three colors magenta and cyan is 0 to 0.5 is used.

The amount of unfixed toner (M / S) on the transfer material is represented by M
When /S=0.5 mg / cm ² , the image density (D0.5) of each color after fixing once usually can be changed by the amount of the colorant added to the toner and the dispersion of the colorant. D
When 0.5 is 1.0 or less, when an a-Si photoreceptor is used and an image is formed under a condition in which a sufficient charging potential is obtained, the density tends to decrease.

When D0.5 is prepared only with the amount of the pigment added, the amount of the pigment in the toner becomes excessive, so that the charge inhibition of the toner occurs, the viscoelasticity changes and the fixability differs,
Further, the pigment is liable to be detached from the toner during the durability, causing fogging and filming, and furthermore, a blade,
Spent tends to occur on the sleeve, and the transparency also deteriorates. Therefore, it is preferable to control D0.5 in consideration of not only the amount of addition but also the selection, dispersion and state of the pigment. However, by controlling the charge inhibition and viscoelasticity of the toner, D
Even when 0.5 is increased, D0.5 is 1.8.
If it is larger, the reproducibility of the halftone is reduced, and in addition, the density gradation is rapidly increased, and the control for environmental fluctuations becomes strict. Therefore, the coloring power D0.5 of the toner of the present invention is preferably from 1.0 to 1.8, and more preferably from 1.1 to 1.7.

When the difference between the maximum value and the minimum value of D0.5 for the three colors yellow, magenta, and cyan is larger than 0.5, the gloss difference in the same image density portion of each color becomes large, and a high-quality image can be obtained. It is difficult to obtain. Further, the environmental characteristics of each toner are easily broadened, and the color balance at the time of full-color formation is easily lost due to temperature and humidity. for that reason,
The difference between the maximum value and the minimum value of D0.5 for the three colors yellow, magenta, and cyan is preferably set in the range of 0 to 0.5. More preferably, it is 0 to 0.4.

Next, the pigment used in the present invention will be described. In the present invention, the kind of the pigment is not particularly limited, but the dispersibility in the resin is improved, the color reproducibility is high, the coloring power is high, the light resistance is high, and further, it does not become a charging inhibitor. It is appropriately determined in consideration of the conditions.

As a yellow pigment used for the yellow toner, CI Pigment Yellow (CIPigmen
t Yellow) 74, 93, 97, 109, 128, 15
1, 154, 155, 166, 168, 180, 185
Is mentioned.

Examples of the magenta pigment used in the magenta toner include quinacridone pigments, CI Pigment Red 48: 2, 57: 1,
58: 2 or CI Pigment Red 5, 31, 146, 147, 15
0, 184, 187, 238, 245, or
Eye Pigment Red (CIPigment Red) 185,
265.

Examples of the cyan pigment used for the cyan toner include a Cu-phthalocyanine pigment and an Al-phthalocyanine pigment. As the Cu-phthalocyanine pigment, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted in a phthalocyanine skeleton having a structure represented by the following formula (I) may be used.

[0109]

Embedded image As the black pigment used for the black toner, any non-magnetic carbon black or organic pigment that exhibits a black color can be used without any problem.

By using these pigments, the dispersibility of the pigment of the toner in the binder resin increases, and as a result, the coloring power increases, low potential development becomes possible, and a good full-color image can be formed.

The content of the yellow pigment is 12 parts by mass or less, preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the binder resin for the yellow toner which is sensitive to the transparency of the OHP film. Parts by weight are preferred. 1
If the amount exceeds 2 parts by mass, the reproducibility of human skin color tends to be inferior as green, red, which is a mixed color of yellow, and as an image.

For the magenta toner and the cyan toner, the content of the magenta pigment or the cyan pigment is preferably 15 parts by mass or less, more preferably 0.1 to 9 parts by mass, based on 100 parts by mass of the binder resin. For the black toner, the content of the black pigment is preferably 15 parts by mass or less, more preferably 0.1 to 9 parts by mass, per 100 parts by mass of the binder resin.
Parts by weight are preferred. To prepare the toner according to the present invention, a pigment or dye as a colorant, a charge control agent, other control agents, and the like are added to the binder resin, if necessary, and the mixture is sufficiently mixed with a mixer such as a ball mill. After mixing, a heating roll, kneader, using a hot kneader such as an extruder, melting and kneading the resin and melting the resins together, dispersing or dissolving the pigment or dye, cooling and solidifying, pulverizing and Strict classification can be performed to obtain the toner particles according to the present invention. However, when the image density (D0.5) is 1.
In order to obtain a toner having a coloring power of 0 to 1.8, it is preferable to perform the following pigment dispersion method when preparing the toner.

That is, in the present invention, in order for the pigment particles in the toner particles to achieve a specific dispersion state as described above, the first binder resin and the pigment particles that are insoluble in the dispersion medium need to be mixed. And a paste pigment containing ペ ー ス ト 50% by mass, charged in a kneader or a mixer, and heated while mixing under non-pressurization to melt the first binder resin. After transferring to the heated first binder resin, that is, the molten resin phase, the first binder resin and the pigment particles are melt-kneaded, and the liquid component is removed and evaporated to dryness.
A mixture obtained by obtaining a first kneaded material having a first binder resin and pigment particles, and then adding a second binder resin to the first kneaded material and, if necessary, additives such as a charge control agent. Is preferably heated and melt-kneaded to obtain a second kneaded product, and the obtained second kneaded product is cooled, pulverized and classified to form a toner. Here, the first binder resin and the second binder resin may be the same or different binder resins.

In the present invention, the paste pigment is
In the first kneaded material production step, it refers to a state where the pigment particles are present only once without undergoing the drying step. In other words, 5 to 50% by mass of pigment particles is present in the form of primary particles with respect to all the paste pigments. The remaining 50-95% by weight of the paste pigment is occupied by the majority of volatile liquids, together with some dispersants and auxiliaries. The volatile liquid is not particularly limited as long as it is a liquid that evaporates by general heating, but water, which is particularly preferably used in the present invention and is preferably used ecologically, is water. In the present invention, the insoluble pigment particles are pigment particles that are insoluble in a dispersion medium, which is a volatile liquid in the paste pigment, and can be dispersed in the paste pigment. For example, if you choose water as the volatile liquid,
All water-insoluble pigment particles are insoluble pigment particles.

The paste pigment used in the present invention contains water-insoluble pigment particles in an amount of 5 to 50% by mass, more preferably 5 to 50% by mass.
It is good to contain 45 mass%. When the content of the insoluble pigment exceeds 50% by mass, the dispersion efficiency in the binder resin is low, the kneading temperature must be high, or the kneading time must be set long. Further, a strong screw or battle configuration is essential for the kneading device, and the polymer chain is likely to be cut.

Conversely, when the paste pigment contains less than 5% by mass of insoluble pigment as solid content, in order to obtain the desired pigment content, a large amount of the paste pigment must be introduced into the mixing device. This is not preferable because the size of the mixing device is increased. Further, when the amount is less than 5% by mass, the water removal step in the step after the first kneading is strengthened, so that water must be completely blown off. As a result, a large load is applied to the binder resin. Will be lost.

When kneading or mixing the paste pigment and the binder resin, the ratio of the pigment to the binder resin in terms of solid content is 10:90 to 50:50, preferably 15:85 to 4: 4.
5:55 is good.

When the ratio of the paste pigment to the binder resin is 1
When the amount is less than 0% by mass, a large amount of binder resin must be charged into the kneader with respect to the paste pigment, and the segregation of the pigment tends to occur in the kneaded material. I have to set it for a long time. In this case, an extra load is applied to the binder resin, and it is difficult to obtain desired resin characteristics.

The ratio of the pigment to the binder resin is 50% by mass.
When the amount is larger, it is difficult to smoothly transfer the pigment particles in the liquid phase to the binder resin. As a result, it is difficult to obtain good dispersibility.

In the present invention, it is preferable to carry out the melt kneading under non-pressurization, because the liquid (for example, water) in the paste pigment attacks the binder resin under pressurization and partially causes the hydrolysis reaction. This may cause the deterioration of the binder resin, or may degrade the offset resistance. Therefore, in the present invention, it is preferable to perform the melt-kneading of the first binder resin and the paste pigment under no pressure.

Examples of the kneading apparatus used in the present invention include a heating kneader, a single-screw extruder, a twin-screw extruder, and a kneader, and particularly preferably a heating kneader.

As the binder resin used in the present invention, various resins conventionally known as binder resins for electrophotography are used.

For example, styrene-based copolymers such as polystyrene, styrene-butadiene copolymer, styrene-acrylic copolymer, polyethylene-ethylene-vinyl acetate copolymer, phenolic resin, epoxy resin, acrylic phthalate resin, polyamide resin In the present invention, when a polyester-based resin is used as a binder resin as a main component, good pigment dispersibility and charge stability can be achieved.

Hereinafter, the polyester resin will be described in more detail.

The polyester resin is obtained by polycondensation of an alcohol component and an acid component. Examples of the acid component constituting the polyester resin preferably used in the present invention include, for example, terephthalic acid and isophthalic acid as aromatic dicarboxylic acids. Acid, phthalic acid, diphenyl-P,
P′-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane-P, P′-dicarboxylic acid, benzophenone-4,
4'-dicarboxylic acid, 1,2-diphenoxyethane-
P, P'-dicarboxylic acid can be used, and as other acids, maleic acid, fumaric acid, glutaric acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid, itaconic acid, citraconic acid, sebacic acid And anhydrides and lower alkyl esters of these acids.

As the dihydric alcohol, the following formula (II)
The diol represented by these is mentioned.

[0127]

Embedded image (Wherein, R 1 is an alkylene group having 2 to 5 carbon atoms;
X and Y are positive numbers and 2 ≦ X + Y ≦ 6) For example, polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2) -2,2- Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-
Bis (4-hydroxyphenyl) propane, polyoxypropylene (13) -2,2-bis (4-hydroxyphenyl) propane and the like can be mentioned.

Other dihydric alcohols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
Examples include diols such as 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, and hydrogenated bisphenol A. Can be

The polyester resin in the present invention includes, for example, maleic acid, fumaric acid, glutaric acid, succinic acid, malonic acid, adipic acid having n-dodecenyl group, isododecenyl group, n-dodecyl group, isododecyl group, isooctyl group and the like. Acids having alkyl or alkenyl substituents and / or ethylene glycol, 1,3-propylene diol, tetramethylene glycol, 1,4-
Alcohols such as butylene diol and 1,5-pentyldiol may be contained.

As a method for producing the polyester resin used in the toner of the present invention, for example, the following method can be mentioned.

First, a linear condensate is formed, and in the process, the molecular weight is adjusted so that the target acid value becomes 1.5 to 3 times the hydroxyl value, and the molecular weight is adjusted to be more uniform than before so that the molecular weight becomes uniform. In order for the condensation reaction to proceed slowly and slowly, for example, (i) react at a lower temperature and for a longer time than before, (ii) reduce the amount of the esterifying agent, (iii) use an esterifying agent with low reactivity, or (Iv) The reaction is controlled by using a combination of these methods. Thereafter, a crosslinking acid component and, if necessary, an esterifying agent are further added under the conditions, and the mixture is reacted to form a three-dimensional condensate. The temperature is further increased, and the reaction is allowed to proceed slowly and for a long time so that the molecular weight distribution becomes uniform. The crosslinking reaction is advanced. When the hydroxyl value or the acid value or the MI (Meit Index) value decreases to the target value, the reaction is terminated. Obtain resin.

In the present invention, the polyester resin preferably has an acid value of 35 mgKOH / g or less, more preferably 30 mgKOH / g or less. When the acid value is 35 mgKOH / g, excellent charging stability can be obtained in each environment. If the acid value of the polyester resin is greater than 35 mgKOH / g, it is difficult to favorably charge the toner positively, and image defects such as low image density and fog are likely to occur.

In the present invention, the glass transition temperature of the toner is 50 to 70 ° C., preferably 52, in consideration of the storability and fixability of the toner and the color mixing with other toners.
The temperature is preferably up to 68 ° C. To make the glass transition temperature of the toner fall within the above range, a binder resin in the toner having a glass transition temperature within the above range may be used. In order to set the glass transition temperature of the binder resin used in the present invention within the above range, it may be appropriately determined from the molecular weight, the material, and the like. When the glass transition temperature of the toner is lower than 50 ° C., although the fixing property is excellent, the anti-offset property is deteriorated, and the contamination on the fixing roller and the winding around the fixing roller may occur. Further, the gloss of the image surface after fixing is too high, and the image quality is sometimes lowered, which is not preferable.

On the other hand, when the glass transition temperature of the toner is higher than 70 ° C., the fixability tends to deteriorate.
The set fixing temperature of the copier body must be increased, and the resulting image generally has low gloss and low color mixing for a full-color toner. The binder resin used in the present invention preferably has a number average molecular weight (Mn) of 1500 to 20.
000, more preferably 2,000 to 15,000, and the weight average molecular weight (Mw) is preferably 6,000 to 10,000.
0, more preferably 8000 to 80000, and Mw
/ Mn is preferably 2 to 10. A binder resin that satisfies the above conditions has good heat fixability, improves the dispersibility of the colorant, reduces the variation in the charge amount of the color toner, and improves the reliability of image quality.

The number average molecular weight (Mn) of the binder resin is 150
When it is less than 0 or when the weight average molecular weight (Mw) is less than 6000, the smoothness of the fixed image surface is high, and the appearance is crisp, but offset tends to occur in durability, and There are also concerns about new problems such as reduced storage stability and occurrence of toner fusion in the developing device. Further, it is difficult to obtain a shear when the toner raw materials are melt-kneaded during the production of the toner particles, and the dispersibility of the chromatic colorant is easily reduced, so that the toner coloring power is easily reduced and the charge amount of the toner is easily changed.

The number average molecular weight (Mn) of the binder resin is 200
If it exceeds 00 or the weight average molecular weight (Mw) is 100
In the case of exceeding 000, all have excellent offset resistance, but the fixing temperature must be increased, and even if the degree of dispersion of the pigment can be controlled, the surface smoothness in the image area is low. It tends to decrease, and the color reproducibility tends to decrease.

When the Mw / Mn of the binder resin is less than 2, the molecular weight itself becomes small. Therefore, similarly to the case where the molecular weight is small, offset development due to durability, deterioration of storage stability, reduction in the developing device, , The toner is easily fused, and the charge amount of the toner tends to vary.

When Mw / Mn of the binder resin exceeds 10, although the offset resistance is excellent, the fixing temperature must be increased, and even if the degree of dispersion of the pigment can be controlled. However, the surface lubricity in the image area tends to decrease, and the color reproducibility tends to decrease.

The toner of the present invention has a softening point temperature Tm calculated from the flow tester curve of 85 ° C. ≦ Tm.
It is preferred that ≦ 120 ° C.

When the softening point temperature Tm of the toner is higher than 120 ° C., although the offset resistance is excellent, it is necessary to increase the fixing temperature, and even if the degree of dispersion of the pigment can be controlled, The surface smoothness in the image portion tends to be significantly reduced, and high color reproducibility cannot be expected.

If the Tm of the toner is lower than 85 ° C., the smoothness of the fixed image is certainly high and the appearance of the image is vivid, but offset tends to occur in the durability.
Further, the storage stability is poor, and there is a concern about a new problem such as fusion of a toner in a developing device. Therefore, the softening point temperature Tm of the color toner is preferably 85 ° C. ≦ Tm ≦ 120 ° C., and more preferably 90 ° C. ≦ Tm ≦ 115 ° C.

The toner according to the present invention may be, if necessary,
A positive charge control agent may be added. The positive charge control agent contains at least one or more selected from the group consisting of quaternary ammonium salts, imidazole compounds, styrene acrylic copolymer resins containing an ammonio group, and phosphonium compounds. It is desirable.

Among them, a quaternary ammonium salt or imidazole, which is a white charge control agent, is preferably used for a color toner. 4 to be contained in the non-magnetic toner of the present invention
The quaternary ammonium salt is represented by the following general formula (III).

[0144]

Embedded image (Wherein, R2 to R5 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an unsubstituted aromatic group or a substituted aromatic group, and A ⁻ represents a counter anion.

Among R2 to R5, at least one group has 6 or more carbon atoms, and further has an alkyl group or alkenyl group composed of 10 or more, especially 12 or more, unsubstituted aromatic group or substituted group. Those which are aromatic groups are preferred.

[0146] Further A ^- as the anion of counters represented ^{by, Cl -, Br -, I} - halogen, such as ion; C
halogenate ions such as lO- ³ , ClO- ⁴ , IO- ³ , and IO- ⁴ ; those represented by the following general formula (IV);

[0147]

Embedded image Based sulfate ion;; ^- CH ₃ SO ₃ sulfonic acid type ion such as _{^{BF 4 -, PF 6 -;}} Mo 7 O 24 6-, H 2 W 12 O 42 10-,
Molybdate ions such as PO ₄ W ₁₂ O ₄₀ ^3- and tungstate ions; heteropoly acid ions containing molybdenum atoms or tungsten atoms, and the like.

Examples of the quaternary ammonium salts used in the present invention include the following. Hoechst V
P2036 (melting point: 200 ° C.), VP2038 (melting point:
215 ° C); TP302 (melting point: 215 ° C), TP415 (melting point: 204 ° C), TP302 manufactured by Hodogaya Chemical Industry Co., Ltd.
4040 (melting point: 209 ° C); A manufactured by Nippon Carlit Co.
-902 (melting point: 210 [deg.] C).

On the other hand, as the functional group for imparting positive charge to the toner in the charge control resin, various groups can be mentioned. In particular, a trisubstituted ammonium group is preferable, and a trialkyl group represented by the following formula (V) is particularly preferable. An ammonio group is more preferred because of its excellent function of imparting positive chargeability.

[0150]

Embedded image (Wherein Ra, Rb and Rc are the same or different,
Represents an alkyl group such as a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a tertiary butyl group, a pentyl group, and a hexyl group;
^- the molybdate ion, phosphate molybdate, chromate molybdate, phosphotungstic acid ion,
Silicotungstate ion, antimonate ion, bismuthate ion, chloride ion, bromide ion, iodine ion, nitrate ion, sulfate ion, perchlorate ion, periodate ion, benzoate ion, naphtholsulfonic acid ion, benzenesulfonic acid Ions, toluenesulfonate, xylenesulfonate, tetraphenylboron, tetrafluoroboron, tetrafluorophosphate, and hexafluorophosphate. )

As the main chain of the charge control resin, various polymer main chains can be employed, but the compatibility with the polyester resin as the fixing resin is particularly important in terms of toner transparency and positive chargeability. It is important to use a polymer main chain having good compatibility with the polyester resin. Examples of such a polymer main chain include styrene-acrylic copolymer resins such as styrene-acrylic acid ester copolymers and styrene-methacrylic acid ester copolymers. When the styrene-acrylic copolymer resin has a main chain, it is preferable that the functional group is substituted with an acrylic ester moiety.

In addition, as the positive charge control agent used in the present invention, an imidazole derivative represented by the following formula (VI) is preferably used.

[0153]

Embedded image (Wherein, R1 ′ to R4 ′ each represent a substituent selected from the group consisting of hydrogen, an alkyl group, an aralkyl group and an aryl group, and these may be the same or different, and may be substituted. X ′ is a phenylene group,
Propenylene group, vinylene group, alkylene group and -C
(R5 ′) represents a linking group selected from the group consisting of R6′—, and R5 ′ and R6 ′ represent a substituent selected from the group consisting of hydrogen, an alkyl group, an aralkyl group and an aryl group. When the substituents of R1 ′ to R4 ′ are further substituted, examples of the substituent include an amino group, a hydroxyl group, an alkyl group, an alkoxy group, and a halogen.

Examples of R1 'to R4' include hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and the like. , Dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl,
Icosyl group, henicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, i-propyl group, i-butyl group, t-butyl group, cyclopentyl group,
Cyclohexyl, benzyl, phenethyl, diphenylmethyl, trityl, cumyl, phenyl, tolyl, xylyl, mesityl, naphthyl and anthryl groups.

In R1 'to R4', the alkyl group preferably has 1 to 25 carbon atoms, the aralkyl group preferably has 7 to 20 carbon atoms, and the aryl group has 6 to 20 carbon atoms. 20 is preferred.

In R5 'and R6', the alkyl group preferably has 1 to 20 carbon atoms, the aralkyl group preferably has 7 to 15 carbon atoms, and the aryl group has 6 to 15 carbon atoms. Good to be.

The imidazole derivative represented by the above formula (VI) used in the present invention can be obtained by reacting the following formula (VII) or (VIII)
The imidazole derivative represented by is particularly preferable.

[0158]

Embedded image In the formula, R 1 ′ and R 2 ′ are an alkyl group having 5 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and 6 to
The followings are the substituents selected from the group consisting of 20 aryl groups, which may be the same or different, and may be substituted. Examples of the substituent in the case of substitution include an amino group, a hydroxyl group, an alkyl group, an alkoxy group, and a halogen.

R3 'to R6' each represent a substituent selected from the group consisting of hydrogen, an alkyl group, an aralkyl group and an aryl group, and these may be the same or different, and may be substituted. good. Examples of the substituent in the case of substitution include an amino group, a hydroxyl group, an alkyl group, an alkoxy group, and a halogen.

Further, the alkyl group of R3 ′ to R6 ′ preferably has 1 to 6 carbon atoms, the aralkyl group preferably has 7 to 15 carbon atoms, and the aryl group has 6 to 15 carbon atoms.
It is good to be 15.

[0161]

Embedded image In the formula, R 1 ′ and R 2 ′ are an alkyl group having 5 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and 6 to 20 carbon atoms.
The followings are the substituents selected from the group consisting of 20 aryl groups, which may be the same or different, and may be substituted. Examples of the substituent in the case of substitution include an amino group, a hydroxyl group, an alkyl group, an alkoxy group, and a halogen.

R3 'and R4' each represent a substituent selected from the group consisting of hydrogen, an alkyl group, an aralkyl group and an aryl group, which may be the same or different, and may be substituted. . Examples of the substituent in the case of substitution include an amino group, a hydroxyl group, an alkyl group, an alkoxy group, and a halogen.

Further, the alkyl group of R3 'and R4' preferably has 1 to 6 carbon atoms, the aralkyl group preferably has 7 to 15 carbon atoms, and the aryl group has 6 carbon atoms.
It is good to be 15

The imidazole derivative represented by the above formula (VII) has excellent dispersibility in a binder resin and further has the above formula (VI)
The imidazole derivative represented by II) has good dispersibility and excellent adhesion to the binder resin, so that sleeve contamination due to detachment of the imidazole derivative from the toner is suppressed.

In the above formulas (VII) and (VIII), R
When the carbon number of the alkyl group of 1 ′ and R2 ′ is less than 5,
In order to lower the positive charge ability and to exhibit the effect as a positive charge control agent, it is necessary to increase the amount of addition. on the other hand,
When the alkyl group, aralkyl group, and aryl group of R1 ′ and R2 ′ have more than 20 carbon atoms, the melting point of the imidazole derivative itself decreases, so that the melt viscosity of the imidazole derivative decreases in the melt-kneading step during toner production. However, since uniform dispersion in the binder resin becomes difficult, deterioration of image characteristics due to poor dispersion is likely to occur,
The binder resin may be restricted.

In the present invention, the imidazole derivative is used in an amount of 0.01 to 20.0 parts by mass, preferably 0.1 to 10.0 parts by mass, more preferably 0.5 to 5.0 parts by mass based on 100 parts by mass of the binder resin. It is preferable to add 0 parts by mass. When the addition amount is less than 0.01 parts by mass, the toner cannot have a sufficient charge amount, and the effect of adding the imidazole derivative may not be exhibited. On the other hand, when the addition amount is more than 20.0 parts by mass, excessive addition results in poor dispersion in the toner, resulting in agglomerates or uneven presence of the imidazole derivative per individual toner particle. This is not preferred.

When using the imidazole derivative in the present invention,
It can be used in combination with a conventionally known positive charge control agent.

The imidazole derivative used in the present invention is synthesized as follows.

Using ethanol as a solvent, an aldehyde and potassium hydroxide as a solvent are added to an imidazole derivative represented by the following general formula (D), and the mixture is refluxed for several hours.
The precipitate formed by refluxing is filtered, washed with water, and then recrystallized again with methanol.

[0170]

Embedded image (R represents a substituent selected from the group consisting of hydrogen, an alkyl group, an aryl group, and an aralkyl group, which may be the same or different.) This synthesis method is an imidazole derivative used in the present invention. Is not limited at all.

Examples of the imidazole derivative used in the present invention (general formulas (1) to (32)) are shown below. These are typical examples in consideration of easy handling. The toner is not limited at all.

[0172]

Embedded image

[0173]

Embedded image The compounds shown below are the same as those having different substituents on the left and right imidazoles, and may be a mixture thereof.

[0174]

Embedded image As the positive charge control agent used in the present invention, a phosphonium compound represented by the following formula (IX) is preferably used.

[0175]

Embedded image When a phosphonium compound is used as the charge control agent, the content in the toner is 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, per 100 parts by mass of the binder resin. When the amount of the positive charge control agent is 0.5 to 10 parts by mass, the colorant is finely and uniformly dispersed in the binder resin, and the triboelectrification of the toner is adjusted to a suitable range. If the amount of the positive charge control agent is less than 0.5 parts by mass, the positive charge control effect of the positive toner is reduced. If the amount of the charge control agent is more than 10 parts by mass, the toner is likely to be charged up under low temperature and low humidity.

The toner according to the present invention may be, if necessary,
Fatty acid metal salts as lubricants (eg zinc stearate,
A fine powder of a polymer containing fluorine (for example, fine powder of polytetrafluoroethylene, polyvinylidene fluoride or the like and a tetrafluoroethylene-vinylidene fluoride copolymer), or tin oxide;
A conductivity imparting agent such as zinc oxide may be added.

Further, in the present invention, the toner may contain a release agent. Examples of the release agent include aliphatic hydrocarbon waxes, oxides of aliphatic hydrocarbon waxes, ester waxes, waxes mainly containing fatty acid esters, saturated linear fatty acids, unsaturated fatty acids, and saturated fatty acids. Examples include alcohols, polyhydric alcohols, fatty acid amides, saturated fatty acid bisamides, unsaturated fatty acid amides, and aromatic bisamides.

As the content of the release agent in the toner,
0.1 to 20 parts by mass of binder resin
The parts by mass, more preferably from 0.5 to 10 parts by mass are good. When the content of the release agent is more than 20 parts by mass, the blocking resistance and the high-temperature offset resistance are liable to decrease, and 0.1% or less.
When the amount is less than the mass part, the releasing effect tends to be small.

These release agents are generally prepared by dissolving a binder resin in a solvent, raising the temperature of the resin solution, and adding and mixing the release agent with stirring, or at least containing the binder resin and a colorant. It is desirable that the toner is contained in the binder resin by a method of mixing a release agent when kneading the toner constituent materials.

For the production of the toner, a method in which another toner constituent material such as a colorant is dispersed in a binder resin solution, followed by spray drying can be applied. In the present invention,
The weight average particle diameter (D4) of the toner is 4.0 to 10.0 μm
m, preferably 5.0 to 9.0 μm. When the weight average particle diameter (D4) of the toner is less than 4.0 μm, it is difficult to stabilize charging, and fog and toner scattering are likely to occur in durability. When the weight average particle diameter (D4) of the toner exceeds 10.0 μm, the reproducibility of the halftone portion is greatly reduced, and the obtained image tends to be a rough image. The weight average particle diameter of the toner can be adjusted to the above range by adjusting the direction of pulverization and classification.

In the toner of the present invention, it is desirable to add an inorganic fine powder such as a fluidity improver as an external additive for the purpose of improving the fluidity of the toner. Any fluidity improver can be used as long as the fluidity can be increased before and after the addition. For example,
Fine powders of metal oxides such as silicic acid fine powder, alumina fine powder, titanium oxide fine powder, zirconium oxide fine powder, magnesium oxide fine powder, zinc oxide; boron nitride fine powder, aluminum nitride fine powder, carbon nitride Nitride such as fine powder; and further, calcium titanate, strontium titanate, barium titanate, magnesium titanate and the like.

The external additive is usually used in an amount of 0.1 to 5 parts by mass based on 100 parts by mass of the toner particles.

In the present invention, in particular, the average primary particle size is 0.1.
It is preferable to use an inorganic fine powder having a hydrophobicity of 001 to 0.2 μm. The inorganic fine powder not only increases the fluidity of the toner, but also does not hinder the chargeability of the toner. Therefore, in the toner of the present invention,
It is preferable that the surface of the inorganic fine powder is subjected to a hydrophobizing treatment with a hydrophobizing agent, so that it is possible to simultaneously impart fluidity and stabilize charging. That is, by being subjected to the hydrophobic treatment, it is possible to improve the environmental characteristics by eliminating the influence of water, which is a factor affecting the charge amount, and reducing the difference in charging ability under high humidity and low humidity. By making it possible and by performing a hydrophobic treatment in the manufacturing process, it becomes possible to prevent aggregation of the primary particles, and it is possible to apply a uniform charge to the toner. Further, the average primary particle size of the titanium oxide fine powder or alumina fine powder in the present invention is preferably 0.001 to 0.2 from the viewpoint of imparting fluidity.
μm, more preferably 0.005 to 0.1 μm.

When the average primary particle size is larger than 0.2 μm,
When the fluidity is reduced, and when the thickness is smaller than 0.001 μm, the toner is easily embedded on the toner surface, and the durability of the toner is easily reduced. This tendency is more remarkable than when applied to a color toner having a sharp melt property. Also, 0.00
If it is smaller than 1 μm, the activity of the inorganic fine powder itself is inevitably high, the particles are likely to aggregate, and it is difficult to obtain the desired high fluidity. The particle size of the inorganic fine powder in the present invention can be measured by a transmission electron microscope.

The hydrophobizing agent used in the present invention may be used for the purpose of surface modification, for example, control of charging characteristics,
Furthermore, depending on the stability and reactivity of charging under high humidity,
What is necessary is just to select suitably. Among these, silane coupling agents having a substituent containing a nitrogen atom in the side chain, titanium coupling agents, and those surface-treated with silicone oil are preferable in terms of positive charge imparting properties.

As the coupling agent having a substituent containing a nitrogen atom in the side chain, any of the conventionally known coupling agents can be used. Among them, a silane coupling agent and a titanium coupling agent can be used. Is preferred.

As the silane coupling agent and the titanium coupling agent, generally, R′mSi—Zn and R′m
Having a structure represented by Ti-Zn (where R 'is an alkoxy group or a halogen atom, Z is a group having an amino group, m and n are integers of 1 to 3, and m + n
= 4. As the substituent containing a nitrogen atom, an amino group is preferable. The amino group may be any of primary amine, secondary amine, tertiary amine and quaternary amine. For example, the following are mentioned.

[0188]

Embedded image _{-NH 2 -NH-CH 3, -NH} -C 2 H 5, -NH-C 3 H 7 -N (CH 3) 2, -N (C 2 H 5) 2, -NH-C _{2 H 4 -NH 2 -N (C} 3 H 6) 2, -NH-C 2 H 4 -N (CH 3) 2 -N (C 4 H 9) 2 -N (CH 3) 3 + Cl -, —N (CH ₃ ) ₃ ⁺ .HCO ₃ ⁻ —N (C ₂ H ₅ ) ₃ ⁺ Cl ⁻ , —N (C ₂ H ₅ ) ₃ ⁺ .HCO ₃ ⁻ —N (C ₃ H ₇ ) ₃ ⁺ Cl ^{_{- -N (C 4 H 9)}} 3 + Cl -

[0189]

Embedded image Along with these coupling agents having a substituent containing a nitrogen atom in the side chain, a coupling agent having no substituent containing a nitrogen atom in the side chain, silicone oil, and hexamethyldisilazane react on the surface. Those adsorbed and adhered are also preferably used.

The BET specific surface area of the inorganic fine powder used as an external additive after the hydrophobizing treatment is 0.1 to 500 m ² /
g is preferable, and more preferably 0.5 to 450 m ² /
g, and more preferably 1 to 400 m ² / g.

The processing amount of the inorganic fine powder used as the external additive is determined by the amount of the inorganic fine powder used as the external additive.
The amount is preferably 0.1 to 70 parts by mass with respect to 00 parts by mass.

In the present invention, the method of hydrophobizing an inorganic fine powder such as a fine silica powder, a fine titanium oxide powder or a fine alumina powder is carried out so that the fine powder has a primary particle size mechanically in a solution. A method of hydrolyzing and treating the coupling agent while dispersing is effective, but is not particularly limited. The treatment may be performed by a gas phase method.

In the present invention, when the treated silicic acid fine powder, the treated titanium oxide or the treated alumina powder is used as the inorganic fine powder, the preferable content is 0.2 to 5 parts by mass with respect to 100 parts by mass of the toner particles. , Preferably 0.3 to 3 parts by mass, more preferably 0.5 to 2.5 parts by mass.

When the amount is less than 0.2 parts by mass, the fluidity of the toner tends to decrease. The detached treated fine powder is liable to contaminate the surface of the two-component developer and the inside of the machine, and it is not preferable because the charge imparting ability of the carrier itself is reduced, and the released treated fine powder is liable to fly to the photoreceptor surface. It can easily cause poor cleaning. Further, when used as a color toner, if a large amount of fine processing powder is contained, OH
The projection image of P is blurred, and a clear image cannot be obtained.

In the present invention, the BET specific surface area of the hydrophobized silica fine powder, the hydrophobized titanium oxide fine powder or the hydrophobized alumina fine powder is 100 m ² / g.
It is preferably at least 130 m ² / g.

If the BET specific surface area is less than 100 m ² / g, it is difficult to obtain high fluidity. In addition, although the BET specific surface area was very high at the stage before the treatment, the BET specific surface area value was greatly reduced in the hydrophobizing treatment step. As a result, the BET specific surface area value was 100 m.
^In the case where the particle size is smaller than ² / g, the inorganic fine powder is not uniformly dispersed in the solution, but reacts with the treating agent in the form of an aggregate, or the treating agent itself is condensed. This case corresponds to a case where a part of the powder becomes oily and adheres to the surface of the inorganic fine powder or the aggregate of the inorganic fine powder, and it is difficult to obtain a desired uniform surface-treated fine powder.

The magnetic carrier used in the two-component developer of the present invention includes, for example, surface-oxidized or unoxidized iron,
Examples include metals such as nickel, copper, zinc, cobalt, manganese, chromium, and rare earths, and magnetic alloys or oxides and ferrites thereof. Further, a binder-type carrier in which magnetic powder is dispersed in a resin can also be used. In the present invention, it is preferable to use a coated carrier obtained by coating the surface of the carrier core with a coating material using the above-described magnetic carrier as a carrier core.

In the coated carrier, the method of coating the surface of the carrier core with the coating material may be a method in which the coating material is dissolved or suspended in a solvent and applied and adhered to the carrier core, or a method in which the coating material is simply mixed in a powder state. Method can be applied.

Examples of the coating material for the carrier core include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. No. These are suitably used alone or in combination.

The treatment amount of the above material may be determined as appropriate, but is preferably 0.1 to 30% by mass (preferably 0.5 to 20% by mass) based on the resin-coated carrier.

Further, in order to stabilize the positive charging property of the toner in the coating material, it is more preferable to disperse a negatively charging additive in the coating material of the carrier. Alternatively, it is also effective to use a resin containing a negatively-chargeable substituent such as fluorine as the coating material or to disperse the resin in the coating material.

As the negatively chargeable additive, a negative charge control agent such as a ditertiary butyl salicylic acid compound of aluminum, a ditertiary butyl salicylic acid compound of chromium, and an azo iron metal complex can be used.
Examples of the resin containing a fluorine-containing substituent include fluorine-modified acrylic, polytetrafluoroethylene, polyvinylidene fluoride, and a copolymer thereof.

The carrier used in the present invention preferably has a 50% volume average particle diameter of preferably 10 to 80 μm, more preferably 20 to 70 μm.

The 50% volume average particle diameter of the carrier is 10 μm.
If the ratio is less than 2, the packing of the two-component developer is strengthened, the mixing property between the toner and the carrier is reduced, the charging property of the toner becomes difficult to stabilize, and the carrier tends to adhere to the surface of the photosensitive drum. Become. When the 50% volume average particle diameter of the carrier exceeds 80 μm, the chance of contact with the toner is reduced, so that a toner having a low charge amount is mixed and fog is easily generated. Further, since the toner tends to be scattered, it is necessary to set the toner concentration in the two-component developer at a low level, and an image having a high image density may not be formed.

As a particularly preferred carrier, the surface of magnetic core particles such as magnetic ferrite core particles is coated with a resin coating material such as silicone resin, fluorine resin, styrene resin, acrylic resin and methacrylate resin on the carrier core. Coated at 0.01 to 5% by mass, preferably 0.1 to 1% by mass, containing not less than 70% by mass of carrier particles of 250 mesh pass, 400 mesh on, and having the above 50% volume average particle size. Magnetic carrier whose particle size distribution is adjusted.

A method for adjusting the magnetic carrier so as to have the above-mentioned 50% volume average particle size and a specific particle size distribution can be carried out, for example, by classification using a sieve. In particular, in order to perform classification with high accuracy, it is preferable to sieve it several times using a sieve having an appropriate opening. It is also effective to use a mesh whose opening shape is controlled by plating or the like.

When a two-component developer is prepared by mixing a toner and a magnetic carrier, the mixing ratio is 2 to 15% by mass, preferably 3 to 13% by mass, as the toner concentration in the developer.
When the amount is set to 4% by mass, more preferably 4 to 10% by mass, usually good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to be low. If the toner concentration is more than 15% by mass, fogging and scattering in the machine tend to occur, and the useful life of the developer tends to be short. The magnetic carrier has a saturation magnetization of 2
0~80Am are preferred of ^{2 / kg (emu / g)} . <3> Method for Measuring Each Physical Property in the Present Invention Next, a method for measuring each physical property will be described below. In addition,
The same measurement was performed in Examples described later. (1) Measurement of toner particle size distribution As a measuring device, for example, Coulter Counter TA
-II or Coulter Multisizer II (manufactured by Coulter) can be used. As the electrolyte, about 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant (preferably an alkylbenzene sulfonate) is used as a dispersant in 100 to 150 ml of the electrolytic aqueous solution.
, 0.1 to 5 ml, and the measurement sample is further
Add g. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the volume and the number of toner particles were measured for each channel by the measuring device using an aperture of 100 μm as an aperture. hand,
The volume distribution and the number distribution of the toner are calculated. then,
The weight average particle size (D4) of the toner based on the weight obtained from the volume distribution of the toner particles (the median value of each channel is set as a representative value for each channel) is obtained.

The channels are 2.00 to 2.52
μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm
m; 4.00 to 5.04 μm; 5.04 to 6.35 μm
m; 6.35 to 8.00 μm; 8.00 to 10.08 μm
m; 10.08 to 12.70 μm; 12.70 to 16.
00 μm; 16.00-20.20 μm; 20.20
25.40 μm; 25.40-32.00 μm;
13 channels of 00 to 40.30 μm are used. (2) Method for measuring 50% volume average particle size of magnetic carrier The average particle size and particle size distribution of the magnetic carrier are obtained by combining a dry dispersion unit RODOS (manufactured by JEOL) with a laser diffraction type particle size distribution measuring device HEROS (manufactured by JEOL). Used, lens focal length 200 mm, dispersion pressure 3.0 × 10 ⁵
Pa, particle size 0.5 μm or more under measurement conditions of measurement time 1-2 seconds
As shown in Table 1, the range of 350.0 μm was measured by dividing it into 31 channels, and the 50% volume average particle diameter (median diameter) of the volume distribution was determined as the average particle diameter. The volume percent of particles in the size range can be determined.

[0209]

[Table 1] The laser diffraction type particle size distribution measuring device HEROS used for measuring the particle size distribution is a device that performs measurement using the Franhofer diffraction principle. To briefly explain this measurement principle, when a laser beam is irradiated from a laser light source to a measurement particle,
A diffraction image is formed on the focal plane of the lens on the opposite side of the laser light source,
The diffraction image is detected by a detector and arithmetic processing is performed to measure the particle size distribution of the measurement particles.

(3) Method of Measuring Magnetic Characteristics of Magnetic Carrier The magnetic characteristics of the magnetic carrier can be measured using a BHU-60 type magnetization measuring device (RIKEN measuring device). About 1.0 g of a measurement sample is weighed, packed in a cell having an inner diameter of 7 mmφ and a height of 10 mm, and set in the above-mentioned apparatus. In the measurement, an applied magnetic field is gradually applied to change the maximum to 238.8 kA / m (3 k Oersted). Next, the applied magnetic field is reduced, and finally a hysteresis curve of the sample is obtained on the recording paper. Than this,
The saturation magnetization can be determined. (4) Method for Measuring Glass Transition Temperature of Binder Resin In the present invention, the glass transition temperature can be measured using a differential thermal analysis measurement device (DSC measurement device), DSC-7 (manufactured by PerkinElmer).

The measurement sample is 5 to 20 mg, preferably 10
Weigh the mg precisely.

This was put into an aluminum pan, and an empty aluminum pan was used as a reference.
The measurement is performed at a temperature rising rate of 10 ° C./min under normal temperature and normal humidity between 00 ° C. In this heating process, an endothermic peak of a main peak in a temperature range of 40 to 100 ° C. is obtained.

At this time, the intersection between the line at the midpoint of the baseline before and after the endothermic peak appears and the differential heat curve is defined as
In the present invention, the glass transition temperature is defined as Tg. (5) Method of Measuring Softening Point Temperature of Toner The measurement of the softening point temperature is performed by using, for example, a flow tester CFT-
It can be measured using Model 500 (manufactured by Shimadzu Corporation). The sample weighs about 1.0 g of a 60 mesh pass product. This is pressurized with a load of 100 kg / cm ² for 1 minute using a molding machine.

The pressurized sample is subjected to a flow tester measurement under the following conditions under normal temperature and normal humidity (temperature: about 20 to 30 ° C., humidity: 30 to 70% RH) to obtain a temperature-apparent viscosity curve.

From the obtained smooth curve, the temperature (= T1 / 2) at which the sample flows out by 50% by volume is determined, and this is defined as the softening point temperature Tm of the toner. RATE TEMP 6.0 (° C / min) SET TEMP 50.0 (° C) MAX TEMP 180.0 (° C) INTERVAL 3.0 (° C) PREHEAT 300.0 (second) LOAD 20.0 (kg) DIE (Diameter) ) 1.0 (mm) DIE (Length) 1.0 (mm) PLUNGER 1.0 (cm ² )

(6) Method for Measuring Molecular Weight of Binder Resin Mn, Mw and Mw / Mn of the binder resin can be measured by gel permeation chromatography (GPC). Stabilize the column in a 40 ° C. heat chamber,
At this temperature, tetrahydrofuran (THF) is flowed as a solvent at a flow rate of 1 ml / min into the column, and about 100 μl of a THF sample solution is injected to measure. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, Tosoh Corporation or Showa Denko KK having a molecular weight of about 10 ² to 10 ⁷ is used, and it is appropriate to use a standard polystyrene sample of at least about 10 points. is there. An RI (refractive index) detector is used as the detector. As the column, it is preferable to use a plurality of commercially available polystyrene gel columns in combination.

For example, Shodex GPC KF-80 manufactured by Showa Denko KK
1, 802, 803, 804, 805, 806, 807, 800P combination, Tosoh TSKgelG1000H (HXL), G2000H (HXL), G3
000H (HXL), G4000H (HXL), G5000H (HXL), G6000H (HXL),
G7000H (HXL), TSKguardcolumn combination.

A sample is prepared as follows.

After placing the sample in THF and leaving it to stand for several hours, it is shaken well, mixed well with THF (until the sample is no longer united), and allowed to stand still for 12 hours or more. Then T
The time of leaving in HF is set to 24 hours or more.
After that, the sample processing filter (pore size 0.45
０．５0.5 μm, for example, Myshodisk H-25-
5 Tosoh Corporation, Exikurodisc 25CR, Germanic
(A product of Science Japan Co., Ltd.) can be used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml. (7) Method for measuring acid value The acid value can be measured as follows.

[0220] 200 to 300 ml of sample 2 to 10 g
Weighed in an Erlenmeyer flask, and methanol: toluene = 3
About 50 ml of a 0:70 mixed solvent is added to dissolve the resin. If the solubility is poor, a small amount of acetone may be added. Using a mixed indicator of 0.1% bromthymol blue and phenol red, a standardized N /
Titrate with 10 potassium hydroxide to alcohol solution, and calculate the acid value from the consumption of potassium alcohol solution by the following calculation. Acid value = KOH (number of ml) × N × 56.1 / sample weight (however, N is a factor of N / 10 KOH)

(8) Measurement method of D0.5 The amount of toner applied on the unfixed transfer material is 0.5 mg / cm ²
The contrast potential of the main body and other development conditions are adjusted so that Thereafter, the image is usually fixed through a fixing device under the same conditions, and the image density is measured. For measuring the image density, a 404 type reflection densitometer manufactured by X-Rite can be used. (9) Method of measuring BET specific surface area of inorganic fine powder Using a fully automatic gas adsorption amount measuring apparatus Autosorb 1 manufactured by Yuasa Ionics Co., Ltd.
Determined by the T multipoint method. Note that, as pretreatment of the sample, degassing is performed at 50 ° C. for 10 hours.

[0222]

An embodiment of the present invention will be described below with reference to the drawings, but the present invention is not limited to the experimental example. <Preparation of Photoreceptor> (1) Preparation of a-Si Photoreceptor A 60 mm-diameter mirror-finished aluminum was manufactured using the same photoreceptor manufacturing apparatus for image forming apparatus by RF-PCVD as shown in FIG. On the cylinder, a positively charged photosensitive member was prepared under the conditions shown in Table 2 and a negatively charged photosensitive member was prepared under the conditions shown in Table 3.

The photoreceptor produced by the method shown in Table 2 was used for a-S
The i photoreceptor 1 and the photoreceptor produced by the method shown in Table 3 are referred to as a-Si photoreceptor 2.

Further, the diameters 15, 20, 40, 80, 10
The a-Si photoreceptors 3 to 7 were prepared using the method shown in Table 2 using a 0-mm aluminum cylinder.

[0225]

[Table 2]

[0226]

[Table 3] <Production of Binder Resin> (1) Production of Binder Resin 1 ・ Polyoxypropylene (2,2) -2,2 bis (4-hydroxyphenyl) propane 15 mol% ・ Polyoxyethylene (2,2) -2 , 2 bis (4-hydroxyphenyl) propane 34 mol% ・ terephthalic acid 15 mol% ・ fumaric acid 36 mol% ・ trimellitic acid 2 mol% These are charged into a four-necked flask, and a reflux condenser, a water separator, a nitrogen gas inlet tube, A thermometer and a stirrer were attached, and condensation polymerization was carried out while introducing nitrogen into the flask.

Further, 500 parts by mass of xylene and 100 parts by mass of a polyester resin were charged into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, a reflux tube, and a device for dropping an isocyanate compound. The polyester resin was dissolved in xylene by heating with stirring. Under reflux of xylene, a xylene solution containing 5 parts by mass of diphenylmethane-4,4 'diisocyanate was added dropwise in a predetermined amount over 2 hours.
After completion of the dropwise addition, stirring was continued for another hour to complete the reaction.
Xylene was distilled off to obtain a urethane-modified polyester resin (1) as a binder resin.

Condensation polymerization similar to that of the polyester resin (1) was carried out by appropriately changing the constituting components and the compounding amount to obtain polyester resins (2) to (6). Table 4 shows the physical properties of the obtained resin and the monomers used.

[0229]

[Table 4] (2) Production of binder resin 2-75 parts by mass of styrene-25 parts by mass of n-butyl acrylate-10 parts by mass of mono-n-butyl malate-0.3 parts by mass of divinylbenzene-1.2 parts by mass of benzoyl peroxide In the liquid, saponified polyvinyl alcohol 0.12
170 parts by mass of water in which parts by mass were dissolved were added, and the mixture was vigorously stirred to obtain a suspension polymerization solution. The suspension dispersion was added to a reactor charged with 300 parts by mass of water and purged with nitrogen, and subjected to suspension reaction polymerization. After completion of the reaction, the resultant was washed with water and dehydrated, and then dried at 40 ° C. for 24 hours to obtain a vinyl resin (7).

The resin (7) had an acid value of 1 as shown in Table 4.
3.2, Tg: 63 ° C, Mn: 6000, Mw: 188
00. <Preparation of Toner> (1) Preparation of Yellow Toner Using the components shown in Table 5, a yellow toner was prepared as follows. Table 5 also shows the physical properties of the obtained yellow toner. (1-1) Preparation of Yellow Toners Y1 to Y18-70 parts by mass of polyester resin (1)-100 parts by mass of paste pigment (CI Pigment Yellow 180 was produced by a known method. A certain amount of water is removed from the previous pigment slurry to a certain extent, and a fixed amount of 30% by mass of a paste pigment (the remaining 70% by mass is water) obtained without a single drying step. First, it is charged into a kneader-type mixer, and the temperature is raised under non-pressure while mixing. When the highest temperature is reached (necessarily determined by the boiling point of the solvent in the paste; in this case, about 90 to 100 ° C.), the pigment in the aqueous phase is distributed or transferred to the molten resin phase, and this is confirmed. After that, the mixture is heated and kneaded for another 30 minutes to sufficiently transfer the pigment in the paste. After that, once the mixer was stopped and the hot water was discharged, one more
Raise the temperature to 30 ° C, heat and knead for about 30 minutes,
After dispersing the pigment and distilling off the water, the process was completed and then cooled to take out the first kneaded product. The water content of the final kneaded product was about 0.8% by mass. 20.0 parts by mass of the first kneaded material (pigment particle content: 30% by mass) 86.0 parts by mass of polyester resin (1) Quaternary ammonium salt (“VP2036” manufactured by Hoechst (melting point: 200 ° C.) )) 4.0 parts by mass Preliminarily mix the above formulation with a Henschel mixer, set the temperature to 120 ° C. with a twin-screw extruder and melt-knead to obtain a second kneaded product, and after cooling, use a hammer mill. And roughly pulverized to about 1 to 2 mm, and then finely pulverized by an air jet type pulverizer to a particle diameter of 40 μm or less. Further, the obtained finely pulverized product is classified and selected so that the weight average particle size in the particle size distribution is 8.0 μm to obtain yellow toner particles (classified product), for the purpose of improving fluidity and imparting charging characteristics. 1.0 part by mass of titanium oxide fine powder hydrophobically treated with a Si-based compound was added to 100 parts by mass of yellow toner particles.
1). The external additives used are shown in Table 8 in detail.

Next, the yellow toners Y2 to Y1 were changed in the same manner except that the kind of the pigment as the colorant and the amount of the pigment added were changed.
2 and Y17 and Y18 were produced.

Next, yellow toners Y13 to Y16 having different toner particle sizes were obtained in substantially the same manner as the yellow toner Y1 except that the pulverization and classification conditions (wind pressure of the pulverizer, air flow of the classifier) and the amount of the external additive were changed. Obtained.

[0233]

[Table 5] (1-2) Preparation of Yellow Toners Y19 and Y20-70 parts by mass of polyester resin (1)-C.I. I. 30 parts by mass of Pigment Yellow 180 The above-mentioned raw materials are charged into a kneader-type mixer, and while mixing, the temperature is raised under non-pressure, and the mixture is sufficiently premixed. Thereafter, the mixture was kneaded twice with three rolls to obtain a first kneaded product. -26.7 parts by mass of the first kneaded material-81.3 parts by mass of polyester resin (1)-4 parts by mass of quaternary ammonium salt The above formulation is sufficiently premixed by a Henschel mixer and melted by a twin screw extruder. The mixture was kneaded to obtain a second kneaded product, and thereafter, a yellow toner Y19 was obtained in the same manner as the yellow toner Y1. Similarly, a yellow toner Y20 was obtained by changing the content of the pigment to 4 parts by mass. (1-3) Preparation of Yellow Toner Y21 100 parts by mass of polyester resin (1) I. Pigment Yellow 180 4 parts by mass • Quaternary ammonium salt 4 parts by mass The above formulation is sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, and then the yellow toner Y21 is prepared in the same manner as the yellow toner Y1. Obtained. (1-4) Preparation of Yellow Toner Y22 The first kneaded product (pigment particle content: 30% by mass) prepared with Yellow Toner Y1 was further kneaded five times with three rolls to disperse the pigment more sufficiently. From the second kneading step, a yellow toner Y22 was obtained in the same manner. (2) Preparation of Magenta Toner (2-1) Preparation of Magenta Toners M1 to M16 The first toner was prepared in substantially the same manner as the yellow toner Y1 except that a paste pigment of a magenta pigment as a colorant shown in Table 6 was used. After obtaining the kneaded product, each was diluted and kneaded to obtain a desired pigment content to obtain a second kneaded product, and thereafter, the weight average particle diameter was 7.5 in the same manner as in the production of the yellow toner Y1.
μm magenta toners M1 to M16 were obtained.

[0234]

[Table 6] (3) Preparation of Cyan Toner (3-1) Preparation of Cyan Toners C1, C2 and C4 to C6 Almost the same as the yellow toner Y1 except that the paste pigment of the cyan application as a colorant shown in Table 7 was used. After the first kneaded product is obtained, the second kneaded product is obtained by diluting and kneading each to obtain a desired pigment content, and the weight average particle size is reduced in the same manner as in the production of the yellow toner Y1. 6.0-
8.0 μm of cyan toners C1 and C2 were obtained. In addition, C4 to C6 were obtained in the same manner as in the production of the yellow toner Y1, except that the external additive was changed from titanium oxide A shown in Table 8 to alumina A.

[0235]

[Table 7]

[0236]

[Table 8] (3-2) Production of Cyan Toner C3 C3 was produced in substantially the same manner as the yellow toner Y21 except that the pigment used as the colorant was changed.

That is, the following raw materials were sufficiently premixed with a Henschel mixer and melt-kneaded with a twin-screw extruder to obtain a cyan toner C3 shown in Table 7 in substantially the same manner as in the production of the yellow toner Y21. -100 parts by mass of polyester resin (1)-C.I. I. Pigment Blue 15: 3 2 parts by mass • Quaternary ammonium salt 4 parts by mass (3-3) Preparation of cyan toners C7 to C9 Instead of the charge control agent used in cyan toner C1, an imidazole compound and an ammonium group-containing styrene acrylic are used. Except for using a polymer resin or a mixture of a quaternary ammonium salt and an imidazole compound, cyan toners C7 to C9 shown in Table 7 were produced in the same manner as in the production of cyan toner C1.
I got (3-4) Production of Cyan Toners C10 to C15 The same procedure as in the production of the cyan toner C1 was performed except that the resins (2) to (7) were used instead of the resin (1) used for the cyan toner C1. The cyan toner C1 shown in Table 7
0-C15 was obtained. (4) Preparation of Black Toner (4-1) Preparation of Black Toner Bk1-70 parts by mass of polyester resin (1)-30 parts by mass of CB-A The above-mentioned raw materials are charged into a kneader type mixer, and the mixture is raised under non-pressure while mixing. Warm and mix well. Thereafter, the mixture was kneaded four times with three rolls to obtain a first kneaded material. -10.0 parts by mass of the first kneaded material-93.0 parts by mass of polyester resin (1)-4 parts by mass of quaternary ammonium salt The above raw materials are sufficiently premixed by a Henschel mixer and melt-kneaded by a twin-screw extruder. Then, a second kneaded product was obtained, and thereafter, a black toner Bk1 shown in Table 9 was obtained in substantially the same manner as in the production of the yellow toner Y1.

Table 10 shows the black pigment used as the coloring agent.

[0239]

[Table 9]

[0240]

[Table 10] (4-2) Preparation of Black Toners Bk2 and Bk3 After obtaining the first kneaded material in substantially the same manner as the black toner Bk1, the blending amount was adjusted so as to obtain a desired amount of carbon black, and the black toner Bk1 was thereafter obtained. The black toners Bk2 and Bk3 shown in Table 9 were obtained in the same manner as in the production of. (4-3) Preparation of Black Toner Bk4 ・ 100 parts by mass of polyester resin (1) ・ 2.0 parts by mass of CB-A ・ 4 parts by mass of quaternary ammonium salt The mixture was melted and kneaded by an extruder, and the rest was obtained in the same manner as in the production of the Bk1 toner to obtain a black toner Bk4 shown in Table 9. (4-4) Production of Black Toners Bk5 and Bk6 Instead of CB-A used for black toner Bk1, C
BB or CB-C, except that the amount of carbon black added was slightly changed.
1 in the same manner as in the production of Black toner Bk shown in Table 9.
5, Bk6 was obtained. (4-5) Preparation of Black Toner Bk7-70 parts by mass of polyester resin (1)-C.I. I. Pigment Yellow 17 7.5 parts by mass I. Pigment Red 5 15 parts by mass I. Pigment Blue 15: 3 7.5 parts by mass The above-mentioned raw materials are charged into a kneader-type mixer, and while mixing, the temperature is raised under non-pressure, and the mixture is sufficiently premixed. Thereafter, the mixture was kneaded four times with three rolls to obtain a first kneaded material. -20.0 parts by mass of the first kneaded material-83.67 parts by mass of polyester resin (1)-3.33 parts by mass of the first kneaded material of CB-A used for producing black toner Bk1-Quaternary ammonium 4 parts by mass of salt The above raw materials were sufficiently premixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, and black toner Bk7 shown in Table 9 was obtained in substantially the same manner as in the production of black toner Bk1. (5) Preparation of carrier and developer A two-component developer using Mn-Mg-Fe-based ferrite as a core agent and coating a nitrogen-containing silane coupling agent and a modified silicone resin formed of a silicone resin at about 0.2% by mass. Carrier (carrier 1) was prepared. The 50% volume average particle size of the carrier 1 was 40 μm.

Next, carriers 2 to 7 were prepared by changing the kind of the core agent, the coating material, and the particle size. Table 11 shows the production method, the particle size of the carrier, and the like.

The above-mentioned carrier is mixed with 5 parts by mass of the toner obtained above so that the total amount becomes 100 parts by mass to prepare a two-component developer.

[0243]

[Table 11] <Experimental example 1> A charge, exposure, development, transfer, and a structure similar to those of the image forming apparatus shown in FIG.
The images were evaluated using an experimental device capable of producing four full-color images with cleaning and static elimination.

The first image forming unit uses yellow toner, the second image forming unit uses magenta toner,
Cyan toner is arranged in the third image forming unit, and black toner is arranged in the fourth image forming unit.
The photoreceptor includes the positively charged photoreceptors 1, 3, 4,
6, 7 were used.

Peripheral speed of photosensitive member (process speed: PS)
Is 200 mm / s, and the surface potential of the photoreceptor is 35 in the development area.
It was set to 0V. Distance between photoconductor and developing sleeve is 400
μm, and the developing sleeve was rotated at twice the peripheral speed of the photoconductor. Image exposure was employed for image formation.

The toner used was Y1 for the yellow toner, M1 for the magenta toner, C1 for the cyan toner, and Bk1 for the black toner.

For image evaluation, the image density when only the black toner was developed, the image density when only the yellow toner was developed, and the image density of the yellow portion when four colors were developed were examined. Table 12 shows the results.

[0248]

[Table 12] When the photoconductor 3 having a diameter of 15 mm is used, the surface potential is 350
V could not be obtained, and a high-density image could not be obtained. For this reason, the peripheral speed of the photoreceptor was reduced to 100 mm / s to perform image output at the same potential. However, even in that case, a sufficient image could not be obtained.

When the photoreceptor 7 having a diameter of 100 mm was used, a sufficient density was obtained in a single color. However, when an image was formed in four colors, the image generated by the first image forming unit was A decrease in image density was observed. It is considered that this is because the toner on the transfer material was re-transferred onto the photosensitive member due to the increase in the diameter of the photosensitive member. <Experimental Example 2> Using the experimental apparatus used in Experimental Example 1, an image was formed using an a-Si photosensitive member 1 having a diameter of 60 mm as a photosensitive member. The charging potential is varied from 250 to 500 V, and the image density in a black image, the variation in the density when the reflection density is 0.6, and the density difference after one round of the exposure part called the ghost and the specific exposure part when the reflection density is 0.6 Was examined. Table 13 shows the results.

[0250]

[Table 13] When the surface potential was smaller than 300 V, the image density was low. On the other hand, when the voltage is higher than 450 V, the dispersion of the density of the image having the reflection density of 0.3 becomes worse, and the drum ghost becomes larger. <Experimental Example 3> The a-Si photosensitive member 1 having a diameter of 60 mm was used as the photosensitive member of the experimental apparatus used in Experimental Example 1, and the dependence of the minimum gap (SD gap) between the photosensitive member and the developing sleeve was evaluated. . The SD gap was varied from 300 to 900 μm, and the fusing and density of the photoreceptor were examined when 10,000 sheets of a black original with 7% printing on an image were imaged. Table 14 shows the results.

[0251]

[Table 14] When the SD gap was smaller than 350 μm, drum fusion occurred. On the other hand, when it was larger than 800 μm, a sufficient image density could not be obtained. <Experimental Example 4> The dependence of the peripheral speed ratio of the sleeve on the a-Si photosensitive member 1 having a diameter of 60 mm was evaluated using the experimental apparatus used in Experimental Example 1. Change the peripheral speed of the sleeve from 1.05 to 5 times the peripheral speed of the photoreceptor, and examine the initial black image density and the image density when 50,000 sheets of black original with 7% printing on the image are printed. Was. Table 15 shows the results.

[0252]

[Table 15] When the sleeve peripheral speed ratio was smaller than 1.1, a decrease in image density was observed from the beginning. When the sleeve peripheral speed ratio was greater than 4.0, the density was reduced after 50,000 sheets were run. Further, fog occurred and a good image was not obtained. <Experimental Example 5> Using the experimental apparatus used in Experimental Example 1, an a-Si photosensitive member 1 having a diameter of 60 mm was used as a photosensitive member, and the image quality dependence on the particle size of the toner was evaluated. Yellow toners Y1 and Y13 to Y16 were used. Table 16 shows the results.
Shown in

[0253]

[Table 16] <Experimental Example 6> An a-Si photosensitive member 1 having a diameter of 60 mm was used as the photosensitive member of the experimental apparatus used in Experimental Example 1, and the image quality dependence on the carrier particle size was evaluated. Table 17 shows the results.

[0254]

[Table 17] When the carrier particle size is smaller than 10 μm, the carrier adheres to the image area from the initial stage of durability, and when the carrier size is smaller than 10 μm, the coating amount on the sleeve is not uniform and the density unevenness is easily generated. . On the other hand, when the carrier particle diameter is larger than 80 μm, the density of spikes formed on the sleeve is coarse, and spikes occur in the halftone portion, resulting in lack of image uniformity. <Experiment 7> Using the experimental apparatus used in Experiment 1, an a-Si photosensitive member 1 having a diameter of 60 mm was used as the photosensitive member, and the dependence of the toner on the coloring power was evaluated. The coloring power of the toner is calculated by calculating the amount of unfixed toner (M / S) on the transfer material by M
The image density (D0.5) after fixing once usually when /S=0.5 mg / cm ² was evaluated. Using Y3 and Y17 to Y22 having different coloring powers for the yellow toner,
Images of 16 gradations were produced with each toner, and the density and gradation were evaluated. The results are shown in FIG.

[0255]

[Table 18] From the results shown in Table 18, when D0.5 is small, a sufficient image density cannot be obtained, and when D0.5 is larger than 1.8, a problem occurs in the reproducibility of the density of intermediate colors due to environmental fluctuations. <Experimental Example 8> Using the experimental apparatus used in Experimental Example 1, an a-Si photosensitive member 1 having a diameter of 60 mm was used as the photosensitive member, and the image dependency on the binder resin of the toner was evaluated. Toner C having a different resin from cyan toner C1
Using 10 to C15, the transition of the density of each resin at the initial stage under low temperature and low humidity environment and at the end of 50,000 sheets durability (initial density → density at 50,000 sheets), image quality under high temperature and high humidity environment, OHP The transparency was evaluated. The results are shown in Table 19.

[0256]

[Table 19]

[0257]

Example 1 A Canon copier CLC1000 was modified and an image was evaluated using an experimental apparatus having the same structure as the image forming apparatus shown in FIG. 1 of the above embodiment.

The first image forming unit uses cyan toner, the second image forming unit uses magenta toner, and the third image forming unit uses magenta toner.
The yellow toner is arranged in the image forming unit, the black toner is arranged in the fourth image forming unit, and the positively charged a-Si photosensitive member 1 manufactured as described above is arranged on the photosensitive member. The peripheral speed (process speed: PS) of the photoconductor is 13
Rotated at 3 mm / s.

The surface potential of the photosensitive member was set to 400 V in the developing region, the distance between the photosensitive member and the developing sleeve was set to 450 μm, and the developing sleeve was rotated at a speed 1.75 times the peripheral speed of the photosensitive member. An image forming apparatus capable of forming 30 images per minute by using image exposure for image formation was manufactured.

The toners include yellow toner Y1, magenta toner M1, cyan toner C1, and black toner Bk1.
, And Carrier 1 was used as the magnetic carrier.

When the transfer force of each color is set to M / S = 0.5 mg / cm ² for the unfixed toner amount (M / S) on the transfer material, the image density after one-time fixing is usually D0.5Y Is 1.4
2, D0.5M is 1.23, D0.5C is 1.30, D
0.5Bk was 1.28. D0.5Y, D
The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of 0.5M and D0.5C was 0.19.

Table 20 shows the gloss difference of each color, the saturation of the color image, and the color reproducibility when the environment changes.

The gloss difference was measured by the following method.

For measurement of gloss (gloss), a VG-10 type gloss meter manufactured by Nippon Denshoku Co., Ltd. was used.

In the measurement, first, the voltage was set to 6 V by a constant voltage device, then the light emitting angle and the light receiving angle were adjusted to 60 °, respectively, and using a zero point adjustment and a standard plate. The image was placed, white paper was further superimposed on three sheets, the measurement was performed, and the numerical value shown on the display was read in%.

As the sample image, an image was prepared for each of the yellow, magenta, and cyan colors with a reading value of 1.50 using an X-Rite 404 type reflection densitometer. The difference between the value and the minimum value was determined.

When the difference in gloss was less than 3, ◎
Less than 10 was evaluated as ○, 6 or more and less than 10 was evaluated as Δ, and 10 or more was evaluated as ×. The measurement of the color saturation of the color image was performed as follows.

The saturation of the image is a value calculated by the following equation. The larger the C *, the clearer the image.

[0269]

(Equation 1) When performing full-color image formation, C * for each color
The greater the spread, the more vivid images can be reproduced for single colors and intermediate colors.

The color tone of the toner was quantitatively measured based on the definition of the color system standardized by the International Commission on Illumination (CIE) in 1976. That is, a * and b * (a * and b * are chromaticities representing hue and saturation) and L * (lightness) were measured. A spectrocolorimeter type 938 manufactured by X-rite was used as the measuring instrument, the light source for measurement was C light source, and the viewing angle was 2 °.

[0271] Sample images were prepared for each of the yellow, magenta, and cyan colors in which the values read by an X-Rite 404 type reflection densitometer were 1.50.
After reading *, the color space that can be formed was determined, and the color saturation was evaluated.

Next, with respect to the color reproducibility when a full-color image using three colors was formed, flesh color and green images were prepared and evaluated.

An image with good color reproducibility for yellow, magenta, cyan, flesh color and green was obtained. ◎ One color is slightly applied to saturation, but the other colors are excellent in color reproducibility. Was evaluated as ○, a substance having some difficulty in color reproducibility but having no problem in practical use was evaluated as Δ, and a substance having difficulty in color reproduction was evaluated as x.

The method of measuring the color reproducibility when the environment fluctuated was performed as follows.

In a low temperature and low humidity environment (23 ° C./5%)
L * (lightness) 55 using yellow, magenta, and cyan
-65, a * and b * are respectively a *: -2 to 2, b
*: A gray image of -2 to 2 was formed. Without changing the setting conditions of the image forming apparatus, the environment is changed to a high temperature and high humidity environment (30 ° C.).
/ 80%), and a gray image was imaged.

Regarding the gray tint fluctuations, those having good tint variations were evaluated as good, those having slight tint variations but having no problem, and those having obvious tint variations were identified as x.
Was evaluated.

[0277]

[Table 20]

[0278]

Example 2 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M5 for the magenta toner, and C2 for the cyan toner.

As a result, D0.5Y was 1.11, D0.
1.15 for 5M, 1.23 for D0.5C, D0.5Bk
Was 1.28. D0.5Y, D0.5M,
The maximum value (D0.5max) and the minimum value (D0.D0.5C) of D0.5C.
5 min) was 0.12.

Table 20 shows the gloss difference of each color, the saturation of a color image, and the color reproducibility when the environment fluctuates.

[0281]

Example 3 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M10 was used for the magenta toner, and C2 was used for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C,
And the gross difference in each color in this case, the saturation of the color image,
Table 20 shows the color reproducibility when the environment changes.

[0283]

Comparative Example 1 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M13 was used for the magenta toner, and C2 was used for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of a color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

As a result of evaluation of the image, the gloss difference between the respective colors was large, and a clear image could not be obtained. Further, the control of the density fluctuation due to the environmental difference was severe, and the density unevenness became severe due to the environmental difference.

[0286]

Example 4 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M5 for the magenta toner, and C4 for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

[0288]

Comparative Example 2 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M5 for the magenta toner, and C5 for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

As a result of evaluation of the images, the gloss difference between the respective colors was large, and clear images could not be obtained. Further, the control of the density fluctuation due to the environmental difference was severe, and the density unevenness became severe due to the environmental difference.

[0291]

Example 5 Evaluation of image formation was performed in the same manner as in Example 1 except that Y18 was used for the yellow toner, M13 was used for the magenta toner, and C5 was used for the cyan toner.

D0.5Y is 1.57 and D0.5M is 1.7.
64, D0.5C 1.69, D0.5Bk 1.2
It was 8. D0.5Y, D0.5M, D
0.5C maximum value (D0.5max) and minimum value (D0.5m
in) was 0.12.

Table 20 shows the gloss difference of each color, the saturation of a color image, and the color reproducibility when the environment fluctuates.

[0294]

Example 6 Image formation was evaluated in the same manner as in Example 1, except that Y18 was used for the yellow toner, M1 for the magenta toner, and C5 for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

[0296]

Comparative Example 3 Image formation was evaluated in the same manner as in Example 1, except that Y18 was used for the yellow toner, M5 for the magenta toner, and C5 for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

As a result of evaluation of the images, the gloss difference between the colors was large, and clear images could not be obtained. Further, the control of the density fluctuation due to the environmental difference was severe, and the density unevenness became severe due to the environmental difference.

[0299]

Example 7 Image formation was evaluated in the same manner as in Example 1 except that Y8 was used for the yellow toner, M13 was used for the magenta toner, and C5 was used for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

[0301]

Comparative Example 4 Image formation was evaluated in the same manner as in Example 1 except that Y5 was used for the yellow toner, M13 was used for the magenta toner, and C5 was used for the cyan toner.

The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5Y, D0.5M, and D0.5C, the gross difference in each color in this case, the saturation of the color image, and the environment Table 20 shows the color reproducibility at the time of fluctuation.

As a result of evaluation of the image, the gloss difference between the colors was large, and a clear image could not be obtained. Further, the control of the density fluctuation due to the environmental difference was severe, and the density unevenness became severe due to the environmental difference.

[0304]

Embodiment 8 A Canon copier CLC1000 was modified and an image was evaluated using an experimental apparatus having the same structure as the image forming apparatus shown in FIG. 1 of the above embodiment.

The first image forming unit uses cyan toner, the second image forming unit uses magenta toner, and the third image forming unit uses magenta toner.
The yellow toner is disposed in the image forming unit, the black toner is disposed in the fourth image forming unit, and the positively charged a-Si photoreceptor 5 manufactured as described above is disposed on the photoreceptor. The peripheral speed (process speed: PS) of the photoconductor is 10
It was rotated at 0 mm / s.

The surface potential of the photosensitive member was set to 320 V in the developing area, the distance between the photosensitive member and the developing sleeve was set to 600 μm, and the developing sleeve was rotated at a speed 1.5 times the peripheral speed of the photosensitive member. An image forming apparatus capable of forming 21 images per minute by using image exposure for image formation was manufactured.

As the toner, Y2 was used for the yellow toner, M2 for the magenta toner, C2 for the cyan toner, and Bk2 for the black toner. Carrier 6 was used as a magnetic carrier.

D0.5Y is 1.41 and D0.5M is 1.41.
41, D0.5C 1.23, D0.5Bk 1.50
Met.

Table 20 shows the gloss difference of each color, the saturation of the color image, and the color reproducibility when the environment changes.

[0310]

Embodiment 9 A Canon copier CLC1000 was modified, and an image was evaluated using an experimental apparatus having the same structure as the image forming apparatus shown in FIG. 1 of the above embodiment.

The first image forming unit uses cyan toner, the second image forming unit uses magenta toner, and the third image forming unit uses magenta toner.
The yellow toner is arranged in the image forming unit, the black toner is arranged in the fourth image forming unit, and the positively charged a-Si photosensitive member 1 manufactured as described above is arranged on the photosensitive member. The peripheral speed (process speed: PS) of the photoconductor is 30
It was rotated at 0 mm / s.

The surface potential of the photoreceptor was set at 380 V in the developing area, the distance between the photoreceptor and the developing sleeve was 450 μm, and the developing sleeve was rotated at a speed three times the peripheral speed of the photoreceptor. For image formation, image exposure is used, and 7
An image forming apparatus capable of forming zero sheets was manufactured.

The toner used was Y3 for the yellow toner, M3 for the magenta toner, C1 for the cyan toner, and Bk7 for the black toner. Carrier 7 was used as a magnetic carrier.

D0.5Y is 1.38 and D0.5M is 1.38.
30, D0.5C is 1.30, D0.5Bk is 1.25
Met.

Table 20 shows the gloss difference of each color, the saturation of the color image, and the color reproducibility when the environment fluctuated.

[0316]

Examples 10 to 20 The image formation evaluation was performed under the same conditions as in Example 1 except that the yellow toner was changed to Y2 to Y12. Table 20 shows the gloss difference for each color, the saturation of the color image, and the color reproducibility when the environment changes.

[0317]

Examples 21 to 35 Evaluation of image formation was performed under the same conditions as in Example 1 except that the magenta toner was changed to M2 to M16. Table 20 shows the gloss difference for each color, the saturation of the color image, and the color reproducibility when the environment changes.

[0318]

Embodiments 36 to 39 Using cyan toners as C2 and C7 to C9
The image formation evaluation was carried out under the same conditions as in Example 1 except for changing to. Table 20 shows the gloss difference for each color, the saturation of the color image, and the color reproducibility when the environment changes.

[0319]

Embodiments 40 to 44 Using black toners as Bk2 and Bk5
The image formation evaluation was performed under the same conditions as in Example 1 except that the values were changed to Bk8. Table 20 shows the gloss difference for each color, the saturation of the color image, and the color reproducibility when the environment changes.

[0320]

Embodiment 45 A Canon copier CLC1000 was modified and an image was evaluated using an experimental apparatus having the same structure as the image forming apparatus shown in FIG. 1 of the above embodiment.

The first image forming unit uses cyan toner, the second image forming unit uses magenta toner, and the third image forming unit uses magenta toner.
The yellow toner is arranged in the image forming unit, the black toner is arranged in the fourth image forming unit, and the negatively charged a-Si photosensitive member 2 manufactured as described above is arranged on the photosensitive member. The peripheral speed (process speed: PS) of the photoconductor is 20
It was rotated at 0 mm / s.

The surface potential of the photosensitive member was set to 380 V in the developing region, the distance between the photosensitive member and the developing sleeve was set to 500 μm, and the developing sleeve was rotated at a speed 1.9 times the peripheral speed of the photosensitive member. Uses back scan exposure for image formation.
An image forming apparatus capable of forming 50 images per minute was manufactured.

The toner used was Y1 for the yellow toner, M1 for the magenta toner, C1 for the cyan toner, and Bk1 for the black toner.

D0.5Y is 1.42 and D0.5M is 1.42.
23, D0.5C 1.30, D0.5Bk 1.28
Met.

Table 20 shows the gloss difference of each color, the saturation of the color image, and the color reproducibility when the environment fluctuated.

[0326]

According to the present invention, it is possible to provide a full-color image forming method and apparatus capable of obtaining a sufficient image density even in low potential development and satisfying high image quality and high durability.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a full-color image forming apparatus using a color image forming method of the present invention.

FIG. 2 is a schematic configuration diagram for explaining a layer configuration of a photoconductor for an image forming apparatus of the present invention.

FIG. 3 is an RF for manufacturing a photoreceptor according to the present invention.
It is a figure which shows an example of the apparatus of -PCVD.

FIG. 4 shows a VH for producing a photoreceptor in the present invention.
It is a figure which shows an example of an apparatus of F-PCVD.

FIG. 5 is a schematic diagram showing first to fourth image forming units of the image forming apparatus of the present invention.

[Explanation of symbols]

 2 Blade 3 Developing sleeve 4 Photoconductor 9 Developing device 10 Magnet 11, 12 Stirring screw 13 Developing chamber 14 Stirring material 15 Power supply 21 Charging device 22 Light emitting element 23 Transfer charging device 24 Transfer paper 25 Fixing device 26 Cleaning device 1100 Photoconductor 1101 Conductive Support 1102 Photosensitive layer 1103 Photoconductive layer 1104 Surface layer 1105 Charge injection blocking layer 1106 Charge generation layer 1107 Charge transport layer 2100, 3100 Deposition device 2111, 3111 Reaction vessel 2112, 3112 Cylindrical support 2113, 3113 Support heating heater 2114 Source gas introduction pipe 2115 High frequency matching box 2200 Source gas supply device 3130 Discharge space

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/113 G03G 9/08 361 15/08 501 351 503 9/10 351 506 9/08 325 507 331 15 / 08 507X 507L (72) Inventor Iku Iku 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Makoto Shinbayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yuji Mikuri 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takaaki Uetaki 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo F-term inside Canon Inc. Reference) 2H005 AA01 AA21 BA00 CA05 CA08 CA21 CA22 CA28 DA03 EA03 EA05 EA10 FA02 2H030 AA05 AA06 AB02 AD02 BB28 BB33 BB71 2H068 DA00 DA71 2H07 7 AD02 AD06 BA07 EA03 GA13

Claims (28)

[Claims] 1. A first toner image formed by a first image forming unit is transferred to a transfer material, and a second toner image formed by a second image forming unit has a first toner image. The third toner image formed by the third image forming unit is transferred onto the transfer material having the first and second toner images, and the fourth toner image formed by the fourth image forming unit is transferred onto the transfer material having the first and second toner images. Of the first, second and third toner images
Is transferred to a transfer material having a toner image of
An image forming method in which a transfer material having third and fourth toner images is transported to a heat and pressure fixing unit and subjected to heat and pressure fixing to form a full-color image or a multi-color image on the transfer material. A) The first image formation in the first image forming unit includes (i) a first charging step of charging an amorphous silicon or a first photosensitive member having an amorphous silicon layer, a first exposure step, (Ii) the first photosensitive member has a diameter of 20 to 80 mm, and the developing region of the photosensitive member facing the developing sleeve in the first charging step is absolutely required. After being charged to a value of 300 to 450 V, an electrostatic image is formed on the first photoconductor by exposure in the first exposure step. (Iii) In the first development step, the first toner and the first toner Magnetic carrier Two-component developer magnetic brush formed on the first developing sleeve comprising, (iv) The first photosensitive member and the first developing sleeve, the minimum clearance 350-80
(V) the first developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the first photoconductor, while the two-component developer is being rotated. The first toner image is developed by the magnetic brush of
(B) the second image formation in the second image forming unit is performed by (i) a second charging step of charging the second photoconductor having amorphous silicon or an amorphous silicon layer. , A second exposure step, and a second development step using a second development sleeve. (Ii) The second photoconductor has a diameter of 20 to 80 mm, and faces the development sleeve in the second charging step. After the developing area of the photoconductor is charged to 300 to 450 V in absolute value, an electrostatic image is formed on the second photoconductor by exposure in the second exposure step. (Iii) In the second development step, A two-component developer including a second toner and a second magnetic carrier forms a magnetic brush on the second developing sleeve; and (iv) a minimum gap between the second photoconductor and the second developing sleeve. Is 350-80
(V) the second developing sleeve rotates at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the second photoconductor, and The second electrostatic image is developed by the magnetic brush of
And (C) a third image formation in the third image forming unit is performed by (i) a third charging step of charging the third photoconductor having amorphous silicon or an amorphous silicon layer. , A third exposure step, and a third development step using a third development sleeve. (Ii) The third photoconductor has a diameter of 20 to 80 mm, and faces the development sleeve in the third charging step. After the developing area of the photoconductor is charged to an absolute value of 300 to 450 V, an electrostatic image is formed on the third photoconductor by exposure in the third exposure step. (Iii) In the third development step, A two-component developer including a third toner and a third magnetic carrier forms a magnetic brush on the third developing sleeve; and (iv) a minimum gap between the third photosensitive member and the third developing sleeve. Is 350-80
(V) the third developing sleeve rotates at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the third photosensitive member, and The third electrostatic image is developed by the magnetic brush of
And (D) a fourth image formation in the fourth image forming unit is performed by (i) a fourth charging step of charging the fourth photoconductor having amorphous silicon or an amorphous silicon layer. , A fourth exposure step, and a fourth development step using a fourth development sleeve.
The photoreceptor has a diameter of 20 to 80 mm. After the developing area of the photoreceptor facing the developing sleeve is charged to an absolute value of 300 to 450 V in the fourth charging step, the electrostatic image is formed by the fourth exposure step. Is formed on the fourth photoconductor, and (ii)
i) in the fourth developing step, a two-component developer including a fourth toner and a fourth magnetic carrier forms a magnetic brush on the fourth developing sleeve, and (iv) a fourth photosensitive member and a fourth photosensitive member. 4
(V) The fourth developing sleeve has a circumference 1.1 to 4.0 times the circumferential speed of the fourth photosensitive member. While rotating at a high speed, a fourth electrostatic image is developed by a magnetic brush of a two-component developer to form a fourth toner image on a fourth photosensitive member. The second toner, the third toner, and the fourth toner have different color tones, and are selected from the group consisting of a nonmagnetic yellow toner, a nonmagnetic magenta toner, a nonmagnetic cyan toner, and a nonmagnetic black toner. (A) The non-magnetic yellow toner, the non-magnetic magenta toner, the non-magnetic cyan toner and the non-magnetic black toner have a positive charge property, and each toner has a weight average particle diameter of 4.0 to 10.0 μm. ,
(B) The 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm, and (c) the transfer force of each color is
The amount of unfixed toner on the transfer material (M / S) is calculated as M / S = 0.5
mg / cm ² , the image density after one fixation is D
0.5, the yellow toner coloring power is D0.5Y,
The coloring power of the magenta toner is D0.5M, the coloring power of the cyan toner is D0.5C, and the coloring power of the black toner is D0.
Assuming 5Bk, D0.5Y, D0.5M, D0.5
C and D0.5Bk are 1.0 to 1.8, respectively, and the coloring power of the toner that exhibits the maximum coloring power among the three colors of yellow, magenta and cyan is D0.5max, and the coloring that exhibits the minimum coloring power When the force is D0.5min, D0.5max
Wherein the difference between D and 0.5 min is 0 to 0.5. 2. The non-magnetic yellow toner is CI Pigment Yellow 7.
4, 93, 97, 109, 128, 151, 154, 1
2. The image forming method according to claim 1, further comprising a yellow pigment selected from the group consisting of 55, 166, 168, 180 and 185. 3. The non-magnetic magenta toner includes a quinacridone pigment or CI Pigment Red 48: 2, 57: 1, 58:
2 or C.I. Pigment Red (CIPig
ment Red) 5, 31, 146, 147, 150, 18
3. The image forming method according to claim 1, further comprising a magenta pigment selected from the group consisting of 4, 187, 238, 245, and CI Pigment Red 185, 265. . 4. The image forming method according to claim 1, wherein the nonmagnetic cyan toner contains a Cu-phthalocyanine pigment or an Al-phthalocyanine pigment. 5. The non-magnetic black toner according to claim 1, wherein the non-magnetic black toner contains a non-magnetic black pigment.
The image forming method according to any one of the above. 6. The D0.5Y, D0.5M, D0.5
The image forming method according to any one of claims 1 to 5, wherein C and D0.5Bk are respectively 1.1 to 1.7. 7. The photoconductor according to claim 1, wherein the first to fourth photoconductors are photoconductors having positively or negatively charged amorphous silicon or an amorphous silicon layer. The image forming method as described in the above. 8. The photoconductor according to claim 1, wherein the first to fourth photoconductors are a photoconductor having a positively charged amorphous silicon or an amorphous silicon layer, and form a latent image by image exposure. 7. The image forming method according to any one of 6. 9. The photoconductor according to claim 1, wherein the first to fourth photoconductors are photoconductors having negatively charged amorphous silicon or an amorphous silicon layer, and form latent images by back scan exposure. 7. The image forming method according to any one of claims 1 to 6. 10. The toner according to claim 1, wherein the first to fourth toners contain at least one of a quaternary ammonium salt, an imidazole compound, a styrene acrylic copolymer resin containing an ammonium group, and a positive charge control agent of a phosphonium compound. The image forming method according to claim 1. 11. The image forming method according to claim 1, wherein the magnetic carrier of the two-component developer has a 50% volume average particle diameter of 20 to 70 μm. 12. The toner according to claim 1, wherein the first to fourth toners are made of a binder resin containing, as a main component, one selected from the group consisting of polyester, styrene acryl and modified products thereof. 12. The image forming method according to claim 11. 13. The polyester has an acid value of 35 mg.
13. The image forming method according to claim 12, wherein KOH / g or less. 14. The toner has a glass transition temperature (T
g) is 50 to 70 ° C.
14. The image forming method according to any one of the above items 13. 15. A first toner image formed by a first image forming unit is transferred to a transfer material, and a second toner image formed by a second image forming unit has a first toner image. The third toner image formed by the third image forming unit is transferred to the transfer material having the first and second toner images, and the fourth toner image formed by the fourth image forming unit is transferred to the transfer material having the first and second toner images. Is transferred to a transfer material having first, second, and third toner images, and the transfer material having first, second, third, and fourth toner images is conveyed to a heat and pressure fixing unit. An image forming apparatus for forming a full-color image or a multi-color image on a transfer material by performing heat and pressure fixing, wherein (A) the first image forming unit comprises (i) amorphous silicon or an amorphous silicon layer First photoreceptor having First charging means, first exposing means, a first developing means having a first developing sleeve has at least provided, (ii) a first photosensitive body diameter 20
８０80 mm, and the developing area of the photoconductor facing the developing sleeve by the first charging means is 300 to 450 in absolute value.
After being charged to V, an electrostatic image is formed on the first photoconductor by exposure by the first exposure unit, and (iii) the first developing unit includes a first toner and a first magnetic carrier. A two-component developer, wherein the two-component developer is the first
A magnetic brush is formed on the developing sleeve of (iv), and the minimum gap between the first photosensitive member and the first developing sleeve is 350 to
(V) the first developing sleeve has a peripheral speed of 1.1 to 4.0 of the first photosensitive member.
While rotating at twice the peripheral speed, the first electrostatic image is developed by a magnetic brush of a two-component developer to form a first toner image on the first photoconductor. The image forming unit includes at least (i) a second photosensitive member having amorphous silicon or an amorphous silicon layer, a second charging unit, a second exposing unit, and a second developing unit having a second developing sleeve. (Ii) the second photoreceptor has a diameter of 20
８０80 mm, and the developing area of the photosensitive member facing the developing sleeve by the second charging means is 300 to 450 in absolute value.
After being charged to V, an electrostatic image is formed on the second photoconductor by exposure by the second exposure unit, and (iii) the second development unit includes a second toner and a second magnetic carrier. A two-component developer, wherein the two-component developer is
(Iv) forming a magnetic brush on the developing sleeve, and (iv) the minimum gap between the second photosensitive member and the second developing sleeve is 350 to
(V) the second developing sleeve has a peripheral speed of 1.1 to 4.0 of the second photosensitive member.
While rotating at twice the peripheral speed, the second electrostatic image is developed with a magnetic brush of a two-component developer to form a second toner image on the second photosensitive member. The image forming unit includes at least (i) a third photosensitive member having amorphous silicon or an amorphous silicon layer, a third charging unit, a third exposing unit, and a third developing unit having a third developing sleeve. (Ii) the third photoreceptor has a diameter of 20
And the developing area of the photoconductor facing the developing sleeve by the third charging means is 300 to 450 in absolute value.
After being charged to V, an electrostatic image is formed on the third photosensitive member by exposure by the third exposure unit, and (iii) the third developing unit includes a third toner and a third magnetic carrier. A two-component developer, wherein the two-component developer is
A magnetic brush is formed on the developing sleeve of (iii), and the minimum gap between the third photosensitive member and the third developing sleeve is 350 to
(V) the third developing sleeve has a peripheral speed of 1.1 to 4.0 of the third photosensitive member.
While rotating at twice the peripheral speed, the third electrostatic image is developed with a magnetic brush of a two-component developer to form a third toner image on the third photosensitive member. The image forming unit includes (i) at least a fourth photosensitive member having amorphous silicon or an amorphous silicon layer, a fourth charging unit, a fourth exposing unit, and a fourth developing unit having a fourth developing sleeve. (Ii) the fourth photoreceptor has a diameter of 20
The developing area of the photoconductor facing the developing sleeve is 300 to 45 mm in absolute value by the fourth charging means.
After being charged to 0 V, an electrostatic image is formed on the fourth photosensitive member by the fourth exposure means, and (iii) the fourth developing means comprises a two-component image including a fourth toner and a fourth magnetic carrier. And a two-component developer forms a magnetic brush on the fourth developing sleeve, and (iv) a minimum gap between the fourth photosensitive member and the fourth developing sleeve is 350 ~ 800
(v) the fourth developing sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the fourth photosensitive member, and the two-component developer is rotated. A fourth toner image is formed on the fourth photosensitive member by developing the fourth electrostatic charge image with the magnetic brush of (E), the first toner, the second toner,
The third toner and the fourth toner have different color tones and are selected from the group consisting of a non-magnetic yellow toner, a non-magnetic magenta toner, a non-magnetic cyan toner and a non-magnetic black toner, and (a) Non-magnetic yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and non-magnetic black toner have positive chargeability, and each toner has a weight average particle diameter of 4.0 to 10.0 μm;
(B) the 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm, and (c) the transfer force of each color is
The amount of unfixed toner on the transfer material (M / S) is calculated as M / S = 0.5
mg / cm ² , the image density after one fixation is D
0.5, the yellow toner coloring power is D0.5Y,
The coloring power of the magenta toner is D0.5M, the coloring power of the cyan toner is D0.5C, and the coloring power of the black toner is D0.
Assuming 5Bk, D0.5Y, D0.5M, D0.5
C and D0.5Bk are 1.0 to 1.8, respectively, and the toner having the maximum coloring power of the three colors of yellow, magenta and cyan has a coloring power of D0.5max and the coloring of the toner having the minimum coloring power. When the force is D0.5min, D0.5m
An image forming apparatus, wherein the difference between ax and D0.5 min is 0 to 0.5. 16. The non-magnetic yellow toner,
I Pigment Yellow 7
4, 93, 97, 109, 128, 151, 154, 1
The image forming apparatus according to claim 15, further comprising a yellow pigment selected from the group consisting of 55, 166, 168, 180, and 185. 17. The non-magnetic magenta toner may be a quinacridone pigment or CI Pigment Red 48: 2, 57: 1, 58:
2 or C.I. Pigment Red (CIPig
ment Red) 5, 31, 146, 147, 150, 18
17. The image forming apparatus according to claim 15, further comprising a magenta pigment selected from the group consisting of 4, 187, 238, 245, and CI Pigment Red 185, 265. . 18. The image forming apparatus according to claim 15, wherein the non-magnetic cyan toner contains a Cu-phthalocyanine pigment or an Al-phthalocyanine pigment. 19. The non-magnetic black toner according to claim 15, wherein the non-magnetic black toner contains a non-magnetic black pigment.
19. The image forming apparatus according to any one of claims 18 to 18. 20. The method according to claim 19, wherein the D0.5Y, D0.5M, D0.
The image forming apparatus according to any one of claims 15 to 19, wherein 5C and D0.5Bk are 1.1 to 1.7, respectively. 21. The photoconductor according to claim 15, wherein the first to fourth photoconductors are photoconductors having positively or negatively charged amorphous silicon or an amorphous silicon layer. The image forming apparatus as described in the above. 22. The photoconductor according to claim 15, wherein the first to fourth photoconductors are photoconductors having positively charged amorphous silicon or an amorphous silicon layer, and form latent images by image exposure. 21. The image forming apparatus according to claim 20. 23. The photoconductor according to claim 15, wherein the first to fourth photoconductors are photoconductors having negatively charged amorphous silicon or an amorphous silicon layer, and form latent images by back scan exposure. 21. The image forming apparatus according to any one of claims 20 to 20. 24. The toner according to claim 1, wherein the first to fourth toners include at least one of a quaternary ammonium salt, an imidazole compound, a styrene acrylic copolymer resin containing an ammonium group, and a positive charge control agent of a phosphonium compound. The image forming apparatus according to any one of claims 15 to 23. 25. The image forming apparatus according to claim 15, wherein the magnetic carrier of the two-component developer has a 50% volume average particle diameter of 20 to 70 μm. 26. The toner according to claim 15, wherein the first to fourth toners are made of a binder resin containing, as a main component, one selected from the group consisting of polyester, styrene acryl and modified products thereof. The image forming apparatus according to any one of claims 25. 27. The polyester has an acid value of 35 mg.
27. The image forming apparatus according to claim 26, wherein KOH / g or less. 28. The toner according to claim 1, wherein the toner has a glass transition temperature (T).
g) is 50-70 ° C.
The image forming apparatus according to any one of claims 27 to 27.