JP2002372820A - Image forming method and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such an image forming method and image forming device which are capable of enhancing color reproducibility and satisfying image densities when low-potential development is performed at a high speed. SOLUTION: An a-Si photoreceptor is used for a black station and OPC photoreceptors are used for color stations in a tandem type image forming method, in which the following conditions are set: The a-Si photoreceptor: The absolute value of the surface potential 300 to 450 V, an SD gap 100 to 500 μm, a developing sleeve is 1.1 to 4.0 times the circumferential speed of the photoreceptor. The OPC photoreceptors: The absolute value of the surface potential 500 to 800 V, an SD gap 350 to 800 μm, the developing sleeves are 1.1 to 4.0 times the circumferential speed of the photoreceptors. The grain size of toners 4 to 10 μm, the grain size of carriers 10 to 80 μm, the softening point of the black toners 90 to 115 deg.C, the softening point of the color toners 85 to 110 deg.C, the softening point of the black toners is higher by 5 deg.C than the softening point of the color toners. The coloring power of the black toners 1.0 to 1.8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a laser beam full color printer, an image forming method and image forming apparatus Ru used for full-color copying machine or the like, especially in a high-speed full-color image formation, the photosensitive member preventing deterioration, running stability And an image forming 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-based photoconductor (a-
Si)] In electrophotography, as a photoconductive material forming a photosensitive layer in a photoreceptor, it has high sensitivity, a high SN ratio [photocurrent (Ip) / dark current (Id)], and has a high spectral characteristic. Have an adapted absorption spectrum,
Characteristics such as quick light response, a desired dark resistance value, and harmlessness to the human body during use are required. 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 abbreviated as "a-Si: H") is a photoconductive material exhibiting such excellent properties. For example, Japanese Patent Publication No. 60-35059 discloses a photoconductive material for an image forming apparatus. The application as a photoreceptor is described.

A photoreceptor for an image forming apparatus using a-Si: H is generally prepared by heating a conductive support to 50 ° C. to 400 ° C. and depositing the conductive support on the support by a vacuum deposition method, a sputtering method, or the like.
A photoconductive layer made of a-Si is formed by a film forming method such as an ion 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.

In Japanese Patent Application Laid-Open No. 54-83746, a conductive support and 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. 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 photoconductor, the temperature near the surface of the photoconductor 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.

[0013] 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.

[0014]

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. However,
Black and white images are still in great demand. Therefore, a color machine and a black-and-white machine are selectively used according to the application, and a copier and a printer exist according to the application and occupy a lot of space. Therefore, in order to save office space, there is a demand for a machine capable of taking a full-color image and a black-and-white image by one unit.

In order to use one color machine and one black-and-white machine, high productivity, high durability and high stability of black-and-white images, low printing cost and high image quality, and high productivity of high-quality full-color images are achieved. There is a need for an image forming method capable of achieving both stability.

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.

By taking full advantage of the features and advantages of these photoconductors, images of yellow, magenta and cyan are formed by a two-component development system using OPC, and black is formed by a one-component development system using an a-Si photoconductor. It is an object of the present invention to provide a high-speed full-color image forming method and an image forming apparatus for forming an image.

[0019]

According to the present invention, there is provided a tandem-type full-color copier in which a yellow, magenta, and cyan color toner is developed by a two-component developing method using OPC. By forming an image and forming a black image by a one-component developing method using an a-Si photoreceptor, high productivity, high durability, high stability, high image quality, and high quality full-color images of black and white images are obtained. It has been found that a full-color image forming method and apparatus capable of achieving both high productivity and high stability 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. The method, wherein (A) the first image formation in the first image forming unit comprises: (i) a first charging step of charging a first photoconductor having an organic photoconductive layer;
The method includes at least a first exposure step and a first development step using a first development sleeve, and (ii) the first photoconductor has a diameter of 20 to 80 mm and faces the development sleeve in the first charging step. The developing area of the photoconductor is 500 to
After being charged to 800 V, an electrostatic image is formed on the first photoconductor by exposure in the first exposure step, and (iii) the first development step includes the first toner and the first magnetic carrier. The two-component developer forms a magnetic brush on the first developing sleeve, and (iv) the first photosensitive member and the first developing sleeve are set so that the minimum gap is 350 to 800 μm. (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, and is charged by the first electrostatic charge by the magnetic brush of the two-component developer. Developing the image to form a first toner image on the first photoreceptor; and (B) forming a second image in the second image forming unit comprises: (i) forming a second image having an organic photoconductive layer; A second charging step of charging the photoconductor, a second exposure step, and a second charging step using a second developing sleeve. Comprising at least an image process,
(Ii) The second photoconductor has a diameter of 20 to 80 mm, and after the developing area of the photoconductor facing the developing sleeve is charged to an absolute value of 500 to 800 V in the second charging step, the second exposure is performed. A second electrostatic image is formed on the second photoreceptor by the exposure in the step, and (iii) in the second developing step, the two-component developer containing the second toner and the second magnetic carrier is used in the second developing step. (Iv) a magnetic brush is formed on the developing sleeve, and (iv) the second photosensitive member and the second developing sleeve are set so that the minimum gap is 350 to 800 μm. The sleeve is rotated at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the second photoconductor, and develops the second electrostatic image with a magnetic brush of a two-component developer to form a second electrostatic image.
(C) forming a third image on the second photoconductor, and (C) forming a third image in the third image forming unit by (i) charging the third photoconductor having an organic photoconductive layer. The method includes at least a charging step, a third exposing step, and a third developing step using a third developing sleeve. (Ii) The third photoconductor has a diameter of 20 to 80 mm, and is developed in the third charging step. After the developing area of the photoconductor facing the sleeve is charged to an absolute value of 500 to 800 V, a third electrostatic image is formed on the third photoconductor by exposure in the third exposure step, and (iii) In the third developing step, the two-component developer including the third toner and the third magnetic carrier forms a magnetic brush on the third developing sleeve, and (iv) the third photosensitive member and the third developing device. The minimum gap between the sleeve and the sleeve is 350-8
(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, and The third electrostatic image is developed by the magnetic brush of FIG.
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 exposing step, and a fourth developing step having a fourth developing sleeve.
The photoreceptor has a diameter of 20 to 80 mm, and 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 photosensitive drum is exposed to light in the fourth exposure step. (Iii) a one-component magnetic developer containing a fourth toner is used in the fourth developing step, and (iv) a fourth electrostatic image is formed on the fourth photoconductor.
The minimum gap between the photoconductor and the fourth developing sleeve is 100
(V) 4th
Of the fourth photosensitive member at a peripheral speed of 1.1 to 4.
While rotating at a peripheral speed of 0 times, the fourth
To form a fourth toner image on the fourth photoconductor, and (E) the first toner, the second toner, and the third toner have different color tones from each other. And a non-magnetic yellow toner, a non-magnetic magenta toner, and a non-magnetic cyan toner.
(A) Non-magnetic yellow toner, non-magnetic magenta toner, non-magnetic cyan toner and magnetic black toner have negative 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, (c) the softening point of the yellow toner is TmY, the softening point of the magenta toner is TmY, and the softening point of the cyan toner is Assuming that TmC and the softening point of the black toner are TmBk, TmY, TmM, and TmC are respectively 85 to 110 ° C, and TmBk is 90 to 115.
° C, and TmBk is 5 ° C or more higher than the maximum of TmY, TmM, and TmC. (D) The amount of unfixed toner (M / S) on the transfer material is M / S = 0.5 mg / cm ² When the image density after one-time fixing is set to D0.5 and the image density (D0.5) of the black toner is set to D0.5Bk, D0.5Bk becomes 0.5 to 1.5. An image forming method comprising:

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. In the apparatus, (A) the first image forming unit includes (i) a first photoconductor having an organic photoconductive layer, a first charging unit, a first exposing unit, and a first developing sleeve. (Ii) the first photoreceptor has a diameter of 20 to 80 mm, and the first charging unit causes the developing area of the photoreceptor facing the developing sleeve to have an absolute value. After being charged to 500 to 800 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. And a two-component developer containing Image agent magnetic brush formed on the first developing sleeve, (iv) a first first photoreceptor
(V) the first developing sleeve has a circumference 1.1 to 4.0 times the circumferential speed of the first photosensitive member. While rotating at a high speed, a first electrostatic image is developed by a magnetic brush of a two-component developer to form a first toner image on a first photoconductor, and (B) a second image forming unit Comprises at least (i) a second photoconductor having an organic photoconductive layer, a second charging unit, a second exposing unit, and a second developing unit having a second developing sleeve. ) The second photoreceptor has a diameter of 20 to 80 mm and is charged by the second charging means.
The developing area of the photoconductor facing the developing sleeve is 5 in absolute value.
After being charged to 00 to 800 V, a second electrostatic image is formed on the second photoconductor by exposure by the second exposure unit, and (iii) the second developing unit includes a second toner and a second toner.
And (iv) forming a magnetic brush on the second developing sleeve, and (iv) forming a magnetic brush on the second developing sleeve. (V) the second developing sleeve rotates at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the second photosensitive member. Meanwhile, the second electrostatic image is developed by the magnetic brush of the two-component developer to form the second toner image on the second photoconductor, and (C) the third image forming unit performs A) a third photoconductor having an organic photoconductive layer, a third charging unit, a third exposing unit,
(Ii) the third photoreceptor has a diameter of 20 to 80 m.
m, and after the developing area of the photoconductor facing the developing sleeve is charged to an absolute value of 500 to 800 V by the third charging means, the third electrostatic image is formed by the exposure by the third exposing means. (Iii) the third developing means has a two-component developer containing a third toner and a third magnetic carrier, and the two-component developer is the third developer.
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 by a magnetic brush of a two-component developer to form a third toner image on the third photoconductor, and (D) a fourth image The 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 photoconductor 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, a fourth electrostatic image is formed on the fourth photoconductor by exposure by a fourth exposure unit, and (iii)
The fourth developing means has a one-component magnetic developer containing a fourth toner, and (iv) the fourth photosensitive member and the fourth developing sleeve are set so that the minimum gap is 100 to 500 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 photoconductor, and the fourth electrostatic charge image is formed by the one-component magnetic developer. To form a fourth toner image on the fourth photoconductor, and (E) a first toner,
The second toner and the third toner have different color tones from each other, and are selected from the group consisting of a non-magnetic yellow toner, a non-magnetic magenta toner, and a non-magnetic cyan toner. Made of black toner,
(A) non-magnetic yellow toner, non-magnetic magenta toner,
The non-magnetic cyan toner and the magnetic black toner have negative chargeability, and the weight average particle diameter of each toner is 4.0 to 1
0.0 μm. (B) the 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm;
(C) The softening point of the yellow toner is TmY, the softening point of the magenta toner is TmM, the softening point of the cyan toner is TmC,
When the softening point of the black toner is TmBk, Tm
Y, TmM and TmC are respectively 85 to 110 ° C, TmBk is 90 to 115 ° C, and TmBk
Is 5 ° C. or more higher than the maximum of TmY, TmM, and TmC, and (d) the amount of unfixed toner on the transfer material (M / S) is M / S
When S = 0.5 mg / cm ² , the image density after one-time fixing is D0.5, and the image density of the black toner (D
(0.5) is D0.5Bk, wherein D0.5Bk has a coloring power of 0.5 to 1.5.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

According to the image forming method and the image forming apparatus of the present invention, in an image forming unit for forming a yellow, magenta, and cyan color toner image, a photosensitive member having an organic photoconductive layer is used as a photosensitive member, and a developer is used as a developer. In the image forming unit for forming a black toner image using a two-component developer composed of a non-magnetic toner of yellow, magenta, and cyan and a magnetic carrier, a photosensitive element having amorphous silicon or an amorphous silicon layer as a photosensitive member is used. And a black one-component magnetic developer as a developer. Hereinafter, the image forming method of the present invention will be described with reference to the drawings, but this does not limit the present invention in any way.

FIG. 1 is a schematic diagram showing an image forming apparatus in which the image forming method of the present invention is carried out, which is an embodiment of an electrophotographic full-color machine.

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 as a photosensitive member is rotatably provided, and the photosensitive drum 4 is uniformly charged by a primary charging device 21 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 each transfer station 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 four color toner images 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.

In the present invention, the color toner image forming unit using the OPC photoreceptor and the a-S
An object of the present invention is to provide a tandem-type full-color copying machine including a black toner image forming unit using an i photoconductor. 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.

Further, 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. Further, it is possible to eliminate problems such as a reduction in density and unevenness due to retransfer when a large-diameter photosensitive member is used, and characteristic unevenness which is a problem in manufacturing a large-diameter drum. <1> Color toner image forming unit in the present invention As described above, in an image forming unit for forming a yellow, magenta, and cyan color toner image, a photoconductor having an organic photoconductive layer as a photoconductor (hereinafter referred to as “OPC Body)) is used.

In the color image forming unit, a two-component developing method using a two-component developer containing yellow, magenta, and cyan color toners and a magnetic carrier is performed, and an OPC photosensitive member having a diameter of 20 to 80 mm is used. Use
In the charging step, the developing area of the photoconductor facing the developing sleeve is charged to an absolute value of 500 to 800V.

When the diameter of the photosensitive member is smaller than 20 mm, the charging width tends to be restricted. The surface potential (charging potential) on the photoreceptor cannot be given a sufficient charging potential in consideration of the charging device capability and high-pressure leak, and high-quality images can be obtained when developing to high-speed full-color copying machines. There are things you can't do. 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 photoconductor 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 image or toner on the transfer material formed by the previous image forming unit is transferred. Is easily retransferred to the photoreceptor. For this reason, toner consumption increases, warpage during transfer is likely to occur. In particular, when forming an image in the fourth station, the image in the first station is the second,
Since retransfer occurs at the third and fourth stations, it becomes more difficult to maintain the image density and to remove the relief. Further, when a large-diameter photosensitive member is used, there is a disadvantage that the size of the apparatus is increased.

Regarding the charging of the OPC photosensitive member, it is desirable that the surface potential of the photosensitive member in the developing region facing the developing sleeve is 500 to 800 V in absolute value. When the surface potential is lower than 500 V, there is a tendency that a sufficient image density cannot be obtained. On the other hand, if it is greater than 800V,
Abrasion of the photoreceptor increases, and the durability life tends to be shortened.
Further, it is not preferable because power consumption increases.

According to the present invention, in the color image forming unit, the minimum gap between the photosensitive member and the developing sleeve is 350 to 8
The photosensitive member is set to a thickness of 00 μm, and is developed with a magnetic brush of a two-component developer while rotating the developing sleeve at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the photosensitive member. It was found that the toner was not fused to the surface, the image density was sufficiently obtained, the toner deterioration was effective, and an image with good dot reproducibility could 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.

Further, the developing sleeve is set at a peripheral speed of 1.
When developing with a magnetic brush of a two-component developer while rotating at a peripheral speed smaller than one time, it is difficult to supply toner required for development, so that a sufficient image density cannot be obtained. On the other hand, 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 is increased, the toner and the magnetic carrier are greatly deteriorated, and the density is reduced after continuous use. Tend to appear remarkably.

The OPC photosensitive member used in the color toner image forming unit according to the present invention will be described below. (A) OPC Photoreceptor in the Present Invention The OPC photoreceptor used in the present invention has a substrate and a resin layer provided thereon, and as a resin layer farthest from the substrate,
It is preferable to provide a protective layer having a crosslinked structure. Providing a long-life and stable image forming apparatus by combining the use of the OPC photoconductor as the photoconductor of the color toner image forming unit of the tandem type image forming apparatus and the use of the amorphous silicon photoconductor as the photoconductor of the black toner image forming unit. it can. As the substrate of the OPC photoreceptor,
Examples include conductive metals such as aluminum and stainless steel. As the organic photoconductive layer used for the OPC photoconductor, an organic photoconductive layer used for a normal OPC photoconductor may be used.

The protective layer is formed of a thermoplastic resin or a curable resin and a material capable of forming a film, or a mixture thereof. In some cases, a film is formed from a gas phase by plasma CVD or the like. A charge transfer material or a resistance adjusting material may be added to maintain electrical characteristics, and organic / inorganic fine particles may be added to improve mechanical characteristics. As the thermoplastic resin, polyester, polycarbonate, polystyrene, polymethacrylate, polyamide,
Examples include polyurethane, polyimide, and polyarylate.

Examples of the curable resin include monomers and oligomers having an organic reactive group, and polymers having a plurality of reactive groups, and those utilizing a sol-gel reaction such as metal alkoxide and colloidal silica. Can be
As the curable material, an acrylic group or a vinyl group as an ethylenic double bond group having an unsaturated double bond, an epoxy group, an isocyanate, a hydroxyl group, a phenolic hydroxyl group, an amino group, a mercapto group, melamine, an alkoxysilane, etc. A compound having the following formula: Various electromagnetic waves such as heat, ultraviolet rays, and electron beams are used for curing, and it is also effective to add various curing agents to promote the curing.

Examples of the charge transfer material used for maintaining electric characteristics include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, and thiazole compounds. Can be

Examples of the resistance adjusting material used to maintain the electric characteristics include conductive metal oxide fine particles, conductive polymers, ionic surfactants, and various salts such as metal salts. As the conductive metal oxide fine particles, one of fine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony-doped tin oxide and zirconium oxide is used. Species or a mixture of two or more can be used. For the purpose of imparting surface sliding properties, ethylene tetrafluoride resin, ethylene trifluoride chloride resin, ethylene hexafluoride chloride propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene dichloride ethylene chloride resin, siloxane resin One or two or more of these copolymers can be appropriately selected, added, and dispersed. Additives such as coupling agents and antioxidants may be added to the protective layer for the purpose of improving adhesion and weather resistance.

As a method of providing a protective layer, when used as a compound for molding, it is used in the form of a film using a known molding method, for example, extrusion molding, molding, injection molding or the like. Further, a film may be formed by coating using a solvent, and after dissolving the composition of the present invention in a suitable solvent, bar coating, spin coating, dip coating, roll coating, applicator coating,
The film may be formed by a known coating method such as a sober roll coating method, a gravure roll coating method, a spray coating method, an electrostatic coating method, and a curtain coating method.
Also, silicon, by sputtering or plasma CVD method,
It is also possible to form an inorganic protective layer containing carbon, fluorine and the like. The thickness of the protective layer is preferably 15 μm or less, more preferably 7 μm or less.

An intermediate layer may be provided between the organic photoconductive layer and the protective layer for the purpose of improving smoothness and durability. As the binder resin used for the intermediate layer, polyester resin, polycarbonate resin, polyurethane resin, phenol resin, epoxy resin, melamine resin, polystyrene resin, polyvinyl butyral resin, polyamide resin, acrylic resin, styrene-butadiene copolymer, styrene- Examples include acrylic copolymers, cellulose, casein, and gelatin. The thickness of the intermediate layer is preferably 0.01 to 1
0 μm, and more preferably 0.1 to 3 μm. Also,
The intermediate layer may further contain an antioxidant, a conductive material, an ultraviolet absorber, a surfactant, and the like.

The organic photoconductive layer, the surface layer and, if necessary, the intermediate layer are laminated to prepare a positively or negatively charged OPC photosensitive member. (B) Developing Device for Color Toner in the Present Invention The developing device used in the color image forming unit is not particularly limited as long as it is a two-component developing system constituting a magnetic brush, and a normal developing device can be used.

FIG. 5 shows an example of a developing device used for a color 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.

The developing chamber 13 and the stirring chamber 14 are provided with first and second stirring screws 11 and 12, 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 conveys a layer of a two-component developer whose layer thickness is regulated by the blade 2, and supplies the developer to the photosensitive drum 4 in a developing region facing the photosensitive drum 4 to develop a 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.
An ordinary exposure apparatus can be used for the color image forming unit. The color image forming unit preferably further includes a transfer unit such as a transfer charging device, a cleaning device, and the like, as shown in FIG. 1, and those used in a normal image forming device may also be used. it can. <2> Black toner image forming unit of the present invention In an image forming unit for forming a black toner image, a photosensitive member having amorphous silicon or an amorphous silicon layer as a photosensitive member (hereinafter, referred to as “a-Si photosensitive member”) In the developing step, a one-component developing method using a one-component magnetic developer containing a magnetic black toner as a developer is performed.

In an image forming station for forming a black image, an a-Si photosensitive member having a diameter of 20 to 80 mm is used.
In the charging step, the developing area of the photoconductor facing the developing sleeve is charged to an absolute value of 300 to 450V.

When the diameter of the photosensitive member is smaller than 20 mm, the charging width tends to be limited. The surface potential (charging potential) on the photoreceptor cannot be given a sufficient charging potential in consideration of the charger performance and high-pressure leakage, and high-quality images can be obtained when developing into high-speed full-color copying machines. There are things you can't do. 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 photoconductor 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 image or toner on the transfer material formed by the previous image forming unit is transferred. Is easily retransferred to the photoreceptor. For this reason, toner consumption increases, warpage during transfer is likely to occur. Further, when a large-diameter photosensitive member is used, there is a disadvantage that the size of the apparatus is increased.

Regarding the charging of the a-Si photosensitive member, it is desirable that the absolute value of the surface potential of the photosensitive member in the developing region facing the developing sleeve is 300 to 450V. When the surface potential is lower than 300 V, there is a tendency that a sufficient image density cannot be obtained. When the voltage is higher than 450 V, in a one-component developing system, it is easy to pick up a defect of the photoconductor such as uneven density due to potential unevenness of the photoconductor and a drum ghost.

In the present invention, the black toner image forming unit has a minimum gap between the photosensitive member and the developing sleeve of 100 to 100.
500 μm, and while rotating the developing sleeve at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the photoconductor,
By performing development by forming a magnetic brush with a one-component magnetic developer of magnetic black toner, the toner does not fuse to the surface of the photoreceptor, sufficient image density can be obtained, and toner deterioration is also effective. It was also found that an image having good dot reproducibility could be stably obtained. When the minimum gap (SD gap) between the photoconductor and the developing sleeve is smaller than 100 μm, the share in the gap increases, and as a result, fusion easily occurs on the photoconductor. On the other hand, if it is larger than 500 μm, the toner flight distance becomes long, and it becomes difficult for the toner to reach the drum, so that a sufficient image density cannot be obtained.

The a-Si photosensitive member used in the black toner image forming unit according to the present invention will be described below. (A) a-Si Photoconductor in the Present Invention FIG. 2 is a schematic configuration diagram for explaining a layer configuration of the a-Si photoconductor in 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 structural view for explaining another layer constitution of the photoreceptor 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
03, 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 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 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.
No. 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 using coherent light such as laser light is to use a conductive support as long as the charge carriers are not substantially reduced. The surface of the surface 1101 may be provided with a concave and convex shape formed by a plurality of spherical trace depressions. That is, the conductive support 1
The surface of 101 has irregularities smaller than the resolving power required for the photoconductor 1100 for an image forming apparatus, and the irregularities are:
This is due to a plurality of spherical trace depressions. Conductive support 1
The unevenness due to the plurality of spherical trace dents provided on the surface of 101 is 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 coherent light such as laser light is used, 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 is preferably formed by a method of forming a vacuum deposited film 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, high-frequency C
AC discharge CVD such as VD method or microwave CVD method
Method, DC discharge CVD method, etc.), sputtering method, vacuum deposition method, ion plating method, optical CVD
And a thin film deposition method such as 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 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 in which the inside can be reduced in pressure, and 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 quality of the layer. 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%.

The substance which can be used as a gas for supplying Si used in the present invention is a substance which is effectively used in the form of gas or silicon hydride (silanes) which can be gasified. 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 photoconductive layer 1103 to be formed, so that the control of the introduction ratio of hydrogen atoms is further facilitated, and a film characteristic which 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.

The raw material gas for supplying halogen atoms used in the present invention is, for example, a gaseous or gaseous gas such as a halogen gas, a halide, an interhalogen compound containing halogen, or a silane derivative substituted with halogen. The obtained halogen compounds 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 field of semiconductors.
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 layer 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.

Incidentally, the above-mentioned conditions are not usually determined independently and separately. Rather, the optimum values are determined based on mutual and organic relevance 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. The surface layer 1104 has a free surface 11106, and is provided to achieve the object of the present invention mainly in moisture resistance, continuous repeated use characteristics, electric pressure resistance, use environment characteristics, and durability.

The surface layer 1104 is made of amorphous silicon (a-Si) based material or amorphous silicon containing hydrogen atoms (H) and / or halogen atoms (X) and further containing carbon atoms (hereinafter referred to as “a”). a-SiC:
H, X), amorphous silicon containing a hydrogen atom (H) and / or a halogen atom (X), and further containing an oxygen atom (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”);
Amorphous silicon containing a hydrogen atom (H) and / or a halogen atom (X) and further containing at least one of a carbon atom, an oxygen atom and a nitrogen atom (hereinafter referred to as “a-SiC
ON: H, X) are suitably used.

In the present invention, in order to effectively achieve the object, the surface layer 1104 is formed by appropriately setting numerical conditions of film forming parameters so as to obtain desired characteristics by a vacuum deposited film forming method. Is preferred. Specifically, for example, an AC discharge CVD method such as a glow discharge method (low-frequency CVD method, high-frequency CVD method, microwave CVD method, or the like)
Method, DC discharge CVD method, etc.), sputtering method, vacuum deposition method, ion plating method, optical CVD
And a thin film deposition method such as 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% with respect to 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 light 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, use environment, for example, under high humidity. The charge characteristics are changed due to the change of the surface structure, and the charge is injected into the surface layer by the photoconductive layer at the time of corona charging or light irradiation, and the charge is trapped by the defects in the surface layer. It is known that the characteristics as a photoconductor for an image forming apparatus are adversely affected, such as occurrence of an afterimage phenomenon.

By controlling the hydrogen content in the surface layer to 30 atomic% or more, defects in the surface layer are significantly reduced, and the electrical characteristics and the high-speed continuous use 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 formed as 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 degree of the above-mentioned electrical insulation is alleviated to some extent, and the non-resonance 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 or the like, and to improve the charging efficiency, the resistance value of the surface layer 1104 is appropriately adjusted when the layer is formed. 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 decreases 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, but not uniformly. 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. Can be used.

In the present invention, the content of the atoms for controlling the 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, a carbon atom,
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 uniformly 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 region of the charge injection blocking layer in the present invention is appropriately determined so that the object of the present invention is effectively achieved. Is done.

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.

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

In addition, in the photosensitive member for an image forming apparatus of the present invention, the conductive support 11
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 for preventing the occurrence of an interference pattern due to the reflected light from the support may be provided. The charge injection blocking layer, the photoconductive layer, the surface layer, and the like are sequentially laminated to produce a positively charged or negatively charged a-Si photosensitive member. (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 an 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 a high-frequency plasma CVD method (referred to as "VHF-PCVD") using a VHF band. 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 for black toner in the present invention The developing device used in the black toner image forming unit is not particularly limited as long as it is a one-component developing system using a one-component magnetic developer constituting a magnetic brush. A developing device can be used.

FIG. 6 shows an example of a developing device for a magnetic one-component black toner, and the structure of the present invention will be described in more detail. However, this does not limit the present invention in any way. In FIG. 6, B denotes an image carrier (so-called photoreceptor) such as a rotating drum type in a transfer type electrophotographic method. Insulator such as a rotating drum type in a transfer type electrostatic recording method. Image carrier in the case of using photosensitive paper or electrostatic recording paper in the direct type electrostatic recording method.
Latent image forming process equipment or process mechanism (not shown)
As a result, an electrostatic latent image is formed, and the surface moves in the direction of the arrow.

E is an overall reference number of the developing device, 2E is a hopper containing toner, 22E is a rotating cylindrical body (hereinafter referred to as a developing sleeve) as a toner carrier, and has built-in magnetic generating means 23E such as a magnetic roller inside. It is. The sleeve 2
2E, the substantially right half peripheral surface thereof is exposed in the hopper 2E and the substantially left half peripheral surface thereof is exposed to the outside of the hopper and is supported by bearings. The shaft 2E is driven to rotate in the direction indicated by the arrow, and the lower end 24E approaches the upper surface of the sleeve 22E. A doctor blade 27E as a toner application member disposed in this way is a stirring member for the toner in the hopper.

The axis of the sleeve 22E is substantially parallel to the generatrix of the image carrier B, and the sleeve 22E has a small gap αE on the surface of the image carrier B.
Are facing each other. Image carrier B and sleeve 22
The surface movement speed (peripheral speed) of each surface of E is substantially the same, or the peripheral speed of the sleeve 22E is slightly faster. The image carrier B and the sleeve 22
DC voltage and AC voltage are superimposed and applied between E by the alternating bias voltage applying means S ₀ E and the DC bias voltage applying means S ₁ E.

The substantially right half peripheral surface of the sleeve 22E is always in contact with the toner reservoir in the hopper 2E, and the toner near the sleeve surface forms a magnetic adhesion layer on the sleeve surface by the magnetic force of the in-sleeve magnetism generating means 23E. , And is adhered and held by electrostatic force. When the sleeve 22E is driven to rotate,
The attached toner layer on the sleeve surface is
In the process of passing through the position E, each part is layered as a thin toner layer T ₁ E having a substantially uniform thickness. The toner is charged mainly by frictional contact between the sleeve surface and the toner in the toner reservoir near the sleeve surface due to the rotation of the sleeve 22E.
The thin toner layer surface of 2E rotates toward the surface of the image carrier B with the rotation of the sleeve, and passes through the developing area A, which is the closest portion between the image carrier B and the sleeve 22E. In this passing process, the toner of the thin toner layer on the side of the sleeve 22E flies by the DC and AC electric fields generated by the DC and AC voltages applied between the image carrier B and the sleeve 22E, and the image carrier B surface of the developing area A, It reciprocates between the sleeve 22E surface. Finally, the toner on the side of the sleeve 22E is selectively transferred and adhered to the surface of the image carrier B according to the potential pattern of the latent image, and the toner images T ₂ E are sequentially formed.

The sleeve surface on which the toner has been selectively consumed after passing through the developing area A is re-rotated into the toner reservoir of the hopper 2E to receive the re-supply of the toner.
To always rotate the toner thin layer T ₁ E surface of the sleeve 22E, repeated copying process is performed.

It is preferable that the black toner image forming unit is further provided with a transfer means such as a transfer charging device, a cleaning device and the like, as shown in FIG. You can use it. <3> Toner in the Present Invention The color toner (yellow toner, magenta toner, cyan toner) in the present invention is a non-magnetic toner having a negative charge, and is used together with a magnetic carrier as a two-component developer.

The black toner of the present invention is a negatively charged magnetic toner and is used as a one-component magnetic developer.

In the present invention, the softening point (TmBk) of the black toner is 90 to 115 ° C., and the softening points of yellow, magenta and cyan (TmY, TmM and Tm, respectively)
C) is 85 to 110 ° C., and TmBk is 5 ° C. or more higher than the maximum of TmY, TmM, and TmC, and the amount of unfixed toner (M / S) on the transfer material is M / S =
The image density after normal fixing once (D0.5) at 0.5 mg / cm ² is defined as the image density of black toner (D0.5).
0.5) is defined as D0.5Bk, D0.5Bk has a coloring power of 0.5 to 1.5, so that both black-and-white images and full-color images have excellent durability and image density. And high quality images can be obtained. When TmY, TmM, and TmC are higher than 110 ° C., 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, the surface in the image area may be controlled. There is a tendency that the smoothness is greatly reduced and high color reproducibility cannot be expected.

When TmY, TmM, and TmC are lower than 85 ° C., the smoothness of the fixed image is high, and although the appearance is clear, offset tends to occur in durability. In addition, storage stability is poor, and there is a concern about a new problem such as fusion of toner in a developing device.

When TmBk is higher than 115 ° C., although the offset resistance is excellent, the fixing temperature must be increased, and a problem may occur in the fixing property in a high-speed machine.

When TmBk is lower than 90 ° C., offset tends to occur in durability. In addition, storage stability is poor, and there is a concern about a new problem such as fusion of toner in a developing device. Further, problems such as filming and fusion to the а-Si photosensitive member are likely to occur.

Further, TmBk is TmY, TmM, TmC
If the temperature is not higher than 5 ° C, the fixing temperature drops to reduce the power consumption and speed of the fixing device, and the color mixing property when a color image is output even under the fixing temperature condition that satisfies the black image. However, there is a tendency that a sufficient image is not displayed again. When TmBk is higher than TmY, TmM, or TmC by 5 ° C. or more, the black toner slightly reduces the gloss of the image, but does not cause any problem in the OHP image or the image definition. Also, in the cleaning of the a-Si photoconductor, it is better to increase the softening point of the black toner. Furthermore, TmB
It is desirable that k be higher than TmY, TmM and TmC by 10 ° C or more. The Tm can be adjusted by adjusting the monomer composition of the resin and the polymerization conditions.

The present invention provides a digital full-color machine for printing many black and white images. As described above, the a-Si photosensitive member is used for the frequently used black image forming station, and the OPC photosensitive member is used for the color image forming station. In this case, if the softening points of the toners are common, when the softening point is low, the fusion to the a-Si photoreceptor tends to be remarkable, and cleaning failure tends to occur. Therefore, TmBk is converted to TmY, TmM, Tm
It is necessary to raise it above mC.

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) after one-time fixing can be changed by the amount of a coloring agent such as a pigment in the toner and the dispersion of the coloring agent. .

The image density (D0.5) of the black toner is D0.5Bk, and the image density (D0.5) of the yellow toner.
Is D0.5Y, image density of magenta toner (D0.5)
Is D0.5M and the image density (D0.5) of the cyan toner is D0.5C, D0.5Bk is 0.5-1.
5, D0.5Y, D0.5M, D0.5C are 1.0 ~
1.8, and D0.5Y, D0.
It is preferable that the difference between the maximum value (D0.5max) and the minimum value (D0.5min) of 5M and D0.5C is 0 to 0.5.

When D0.5Bk is 0.5 or less, the saturated image density is insufficient, and when D0.5Bk is 1.5 or more, fixing offset is likely to occur, which is not preferable.

D0.5Y, D0.5M, D0.5
When C is 1.0 or less, there is a tendency that a sufficient image density cannot be obtained. When D0.5 is increased only by the amount of the pigment added,
Because the amount of pigment in the toner is excessive, charge inhibition of the toner occurs, the viscoelasticity changes and the fixability differs, and the pigment is more likely to be detached from the toner during durability, causing fogging, filming, and the like. Further, carrier spent and the like are likely to occur. Therefore, D0.5 must be controlled in consideration of not only the addition amount but also the selection, dispersion, and state of the pigment. However, even when the charge inhibition and viscoelasticity of the toner are controlled to increase D0.5,
When D0.5Y, D0.5M, and D0.5C are larger than 1.8, the halftone reproducibility is reduced, and the density gradation is rapidly increased, and the control over environmental fluctuations becomes unfavorable. . Therefore, D0.5Y, D
As for 0.5M and D0.5C, 1.0-1.8 is desirable,
Preferably, 1.1 to 1.7 is good. Also, D0.5Y,
The difference between the maximum value (D0.5max) and the minimum value (D0.5min) of D0.5M and D0.5C is 0 to 0.5 from the viewpoint of uniformity, color mixing, and coloring at the time of full-color image formation. It is desirable. Next, the developer and the toner in the present invention will be specifically described. (A) Color toner and two-component developer containing color toner First, 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,
It is appropriately determined in consideration of the high light fastness and the fact that it does not act as a charge inhibiting factor.

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

Examples of the magenta pigment used for 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 in 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 (1) may be used.

[0131]

Embedded image 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 OH
The amount of the yellow toner sensitive to the transmittance of the P film is 12 parts by mass or less, preferably 0.5 to 8 parts by mass, per 100 parts by mass of the binder resin. If the amount exceeds 12 parts by mass, the reproducibility of human flesh color tends to be inferior as a mixed color of yellow, green and red, 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.

To produce the color 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 mixed with a ball mill or the like. After mixing thoroughly, using a hot kneader such as a heating roll, kneader, or extruder, melt or knead the resin to melt the resins together, disperse or dissolve the pigment or dye, and cool. After solidification, pulverization and strict classification are performed to obtain the toner particles according to the present invention.

When the amount of unfixed toner (M / S) is M / S = 0.
When the image density (D0.5Y, D0.5M, D0.5C) after fixing once is usually 5 mg / cm ² ,
In order to obtain a color toner having a coloring power of 1.8, it is preferable to perform the following pigment dispersion method when producing the toner. That is, in the present invention, to achieve a specific dispersion state of the pigment particles in the color toner particles, the first binder resin and the pigment particles insoluble in the dispersion medium are contained in an amount of 5 to 50% by mass. The paste pigment is charged into a kneader or a mixer and heated while mixing under non-pressure to melt the first binder resin, and the paste pigment, that is, the pigment in the liquid phase, is heated. After the transition to the binder resin, ie, 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 above-mentioned paste pigment is
In the production process of the first kneaded product, it refers to a state where the pigment particles are present only once without undergoing the drying process. 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 the dispersion medium that is a volatile liquid in the paste pigment and can be dispersed in the paste pigment. For example, when water is selected 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 in solid content, in order to obtain the desired pigment content, a large amount of the paste pigment must be added to the mixing device. This is not preferable because the size of the mixing device is increased. Further, when the content is less than 5% by mass, the step of removing water 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 preferably 10:90 to 50:50, and more preferably 15:85 to 45:55.

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 more, the transition of the pigment particles in the liquid phase to the binder resin is difficult to be performed smoothly, in addition, even during the melt-kneading after the migration of the pigment particles, the kneaded material is less likely to show a uniform molten state. As a result, it is difficult to obtain good dispersibility.

In the present invention, it is preferable to carry out 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 cause the offset resistance to deteriorate. 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.

The polyester resin will be described in more detail below.

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, maleic acid, fumaric acid, glutaric acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid, itaconic acid, citraconic acid, sebacic acid, anhydrides of these acids, lower Alkyl esters can be used.

As the dihydric alcohol, the following formula (2)
The diol represented by these is mentioned.

[0149]

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. And / or an acid having an alkyl or alkenyl substituent such as ethylene glycol, 1,3-propylene diol, tetramethylene glycol, 1,4-butylene diol, and 1,5-pentyl diol. .

Examples of the method for producing the polyester resin used in the toner of the present invention include the following methods.

First, a linear condensate is formed, and in the process, the molecular weight is adjusted so that the target acid value is 1.5 to 3 times the hydroxyl value, and the molecular weight is made higher than in the conventional art 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 these methods in combination. 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. Further raise the temperature, slowly so that the molecular weight distribution becomes uniform,
The reaction is allowed to proceed for a long time, the crosslinking reaction proceeds, and when the hydroxyl value or the acid value or the MI value decreases to the target value, the reaction is terminated to obtain a polyester resin.

In the present invention, the polyester resin has an acid value of 2 to 50 mgKOH / g, preferably 3 to 40 mgKOH / g.
OH / g, more preferably 5 to 30 mgKOH / g, is preferable because excellent charging stability can be obtained in each environment.

The acid value of the polyester resin is 2 mg KOH /
When the value is smaller than g, the toner tends to be charged up and tends to cause an image density list in a low-temperature and low-humidity environment. Further, the dispersibility of the colorant in the binder resin is reduced, and the amount of charge between the toner particles is likely to be different. When the acid value of the polyester resin is more than 50 mgKOH / g, the stability over time of charging of the toner decreases,
The amount of charge tends to decrease with durability. Particularly in a high-temperature and high-humidity environment, image defects such as toner scattering and fogging are likely to occur. In addition, as a resin satisfying the acid value of 2 to 50 mgKOH / g, a hybrid resin composed of a polyester unit and a vinyl copolymer unit, and a mixture of a polyester resin and a vinyl copolymer are also preferably used.

In the present invention, the glass transition temperature of the toner is 50 to 70 ° C., preferably 52, when taking into account 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. The glass transition temperature of the binder resin used in the present invention can be adjusted to the above range by appropriately adjusting the molecular weight, the material, and the like.

When the glass transition temperature of the binder resin is less than 50 ° C., although the fixing property is excellent, the offset resistance is deteriorated, and the fixing roller is contaminated and the fixing roller is wrapped. Further, the gloss of the image surface after fixing becomes too high, and the image quality deteriorates, which is not preferable. When the glass transition temperature of the binder resin is higher than 70 ° C., the fixing property is deteriorated, and the fixing temperature of the copying machine must be increased, and the obtained image generally has low gloss.
In addition, the color mixing property is reduced for a full-color toner.

The binder resin used in the present invention has a number average molecular weight (Mn) of preferably 1500 to 20,000, more preferably 2,000 to 15,000, and a weight average molecular weight (Mw) of preferably 6,000 to 100,000, more preferably. Is 8000 to 80000, and Mw / Mn is preferably 2 to 10. A resin that satisfies the above conditions has good thermal 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 the weight average molecular weight (Mw) is less than 6000 or less than 6000, the surface of the fixed image has a high smoothness, and the appearance is vivid, but offset tends to occur in the durability, and the storage resistance is poor. There are also concerns about new problems such as reduced stability, fusion of the toner in the developing device, and the occurrence of carrier spent due to toner components adhering to the magnetic carrier surface. Further, it is difficult to obtain a shear when the toner raw materials are melt-kneaded during the production of the color toner particles, the dispersibility of the colorant is easily reduced, and therefore, the coloring power of the toner is 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
If it exceeds 000, all have excellent offset resistance, but the fixing set 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 reduced. 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 above-mentioned molecular weight is small, offset development due to durability, deterioration of storage stability, deterioration in the developing device, etc. Fusing and carrier spent tend to occur, and the charge amount of the toner tends to fluctuate.

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. In addition, the surface lubricity in the image portion is reduced, and the color reproducibility is easily reduced.
The color toner according to the invention is preferably a negatively chargeable toner because charging is easily stabilized. In particular, in a toner in which a highly negatively chargeable polyester resin is used as a binder resin and a colorant is dispersed in advance, the charge is easily stabilized, and excellent durability and high image quality can be obtained.

The color toner of the present invention may optionally contain a negative charge control agent, and preferably contains an organometallic compound. Preferably,
Metal compounds of aromatic carboxylic acid derivatives, for example, metal compounds of salicylic acid and metal compounds of alkyl salicylic acid are mentioned.

In the present invention, a chromium compound or an aluminum compound of di-tert-butylsalicylic acid is preferable, and the interaction with the binder resin enables control of the softening point of the toner during kneading. This effect is rarely seen with metal compounds such as zinc.

When the metal compound of the aromatic carboxylic acid is contained in the toner resin, the content thereof is as follows.
0.5 to 10 parts by mass per 0 parts by mass, more preferably 1 to 10 parts by mass
8 parts by mass. When the metal compound of the aromatic carboxylic acid is 0.
When the amount is 5 to 10 parts by mass, the crosslinking reaction with the resin proceeds favorably during melt-kneading, the colorant is finely and uniformly dispersed in the resin, and the negative triboelectric chargeability of the toner is adjusted to a suitable range. It is preferred. When the amount of the metal compound of the aromatic carboxylic acid is less than 0.5 parts by mass, the crosslinked portion of the resin is small and the melt viscosity does not increase, or even if it increases, the rate of increase is small, and the negative charge control effect of the toner is small. If the amount of the metal compound of the aromatic carboxylic acid is more than 10 parts by mass, the metal crosslinked portion of the resin becomes too large, and the low-temperature fixability of the toner and the color mixing with other color toners are reduced. Further, under low temperature and low humidity, the toner is liable to be charged up.

The color toner of the present invention causes a cross-linking reaction by the interaction between the binder resin and the metal compound of the aromatic carboxylic acid, thereby increasing the share of the colorant on the secondary particles during kneading. , Which disperses the colorant finely and uniformly, has excellent rapid melting property even at low temperature side during heating and pressing fixation, exhibits strong elastic properties at high temperature side, and hardly causes offset. It is a toner designed to be.

The color toner according to the present invention may contain, if necessary, a fatty acid metal salt (eg, zinc stearate, aluminum stearate, etc.) as a lubricant, and a fine powder of a fluorine-containing polymer (eg, polytetrafluoroethylene, polyvinylidene fluoride). And a conductivity-imparting agent such as tin oxide or zinc oxide.

Further, in the present invention, the color toner may contain a release agent. For example, aliphatic hydrocarbon-based waxes, oxides of aliphatic hydrocarbon-based waxes, ester waxes, waxes mainly containing fatty acid esters, saturated linear fatty acids, unsaturated fatty acids, saturated alcohols,
Examples include 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 is small.

These release agents are usually 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 containing at least a 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 and then spray-dried can be applied. In the present invention, the color toner has a weight average particle diameter (D4) of 4.0 to 10.0 μm, and 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. The toner has a weight average particle size (D4) of 1
If the thickness exceeds 0.0 μm, the reproducibility of the halftone portion is greatly reduced, and the obtained image becomes a rough image. The weight average particle diameter of the toner can be adjusted to the above range by adjusting the conditions of pulverization and classification.

In the color 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. For example, fine powders of metal oxides such as silica 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, Nitride such as fine carbon powder; and calcium titanate, strontium titanate, barium titanate, magnesium titanate and the like. In the present invention, in particular, the average primary particle size is 0.0
01-0.2 μm, more preferably 0.005-0.1
Titanium oxide fine powder or alumina fine powder of μm is preferable because it has good fluidity and the charge of the negatively chargeable color toner becomes uniform, so that toner scattering and fogging hardly occur. Further, the toner is less likely to be embedded in the surface of the color toner particles, so that toner deterioration hardly occurs, and the durability of a large number of sheets is improved. This tendency is more remarkable in a color toner having a sharp melt property.

[0172] While the silica fine particles themselves have a strong negative chargeability, the titanium oxide fine powder or the alumina powder has a substantially neutral chargeability.
It can be controlled to the desired charging level. The external additive is usually used in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the toner particles.
Used in parts by weight.

The above-mentioned external additives not only increase the fluidity of the toner, but also do not hinder the chargeability of the toner. Therefore, in the toner of the present invention, the external additive is preferably subjected to a surface 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.

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. For example, alkyl alkoxy lan,
A silane-based organic compound such as siloxane, silane, or silicone oil, which does not itself thermally decompose at the reaction treatment temperature, is preferable.

Particularly preferred is an alkylalkoxylan represented by the following formula (3) having a volatile group such as a coupling agent and having both a hydrophobic group and a highly reactive coupler. Good to use.

[0176]

## STR3 ## R _m SiY _n (3) (wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y is an alkyl group, vinyl group, glycidoxy group, a hydrocarbon group such as methacryl group And n represents an integer of 1 to 3, provided that m + n = 4.) As the alkoxysilane represented by the formula (3), for example, vinyltrimethoxysilane, vinyltriethoxysilane, γ- Methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane , N-hexadecyltrimethoxysilane, n-
Octadecyltrimethoxysilane can be mentioned. More preferably, it is an alkoxysilane compound represented by the following formula (4).

[0177]

Embedded image _{C a H 2a + 1 -Si- (} OC b H 2b + 1) 3 (4) ( wherein, a is an integer of 4 to 12, b is an integer of 1-3.) Here, when a in the general formula is smaller than 4, the hydrophobic treatment becomes easy, but it is difficult to obtain hydrophobicity. Also, if a is 13
If it is larger, the hydrophobicity becomes sufficient, but coalescence between the fine powders increases, and the flowability-imparting ability tends to decrease. On the other hand, if b is larger than 3, the reactivity decreases, and it is difficult to sufficiently perform the hydrophobic treatment. Therefore, in the present invention, a is preferably 4 to 12, more preferably 4 to 8, and b is preferably 1 to 3, and more preferably 1 to 2.

The amount of the hydrophobizing agent to be treated is 1 to 100 parts by mass of titanium oxide fine powder or alumina fine powder.
It is 50 parts by mass, preferably 3 to 45 parts by mass. The treated titanium oxide has a degree of hydrophobicity of 30 to 90%, preferably 40 to 80%. 30% hydrophobicity
When the particle size is smaller than the above range, the charge amount is greatly reduced due to long-term storage at a high humidity. When the hydrophobicity exceeds 90%, it is difficult to control the charge of the titanium oxide fine powder or the alumina fine powder itself. However, it is not easy to charge up easily. In the present invention, the particle size of the external additive is measured by a transmission electron microscope.

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 of dissolving or suspending the coating material in a solvent, applying the coating material, and adhering the coating material to the carrier core, or a method of mixing 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-mentioned 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.

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

When the 50% particle size of the carrier is less than 10 μm, the packing of the two-component developer is strengthened, the mixing property between the toner and the carrier is reduced, and the chargeability of the toner is hardly stabilized. Is more likely to adhere to the surface of the photosensitive drum. 50% particle size of carrier is 80μ
If m exceeds m, the chance of contact with the toner is reduced, so that toner with a low charge amount is mixed and fog is likely to occur. 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 may be coated with a resin coating material such as a silicone resin, a fluorine resin, a styrene resin, an acrylic resin or a methacrylate resin on the carrier core. Coat 0.01 to 5% by mass, preferably 0.1 to 1% by mass, contain 70% by mass or more of carrier particles of 250 mesh pass, 400 mesh on, and have the above 50% volume average particle size. Magnetic carrier whose particle size distribution is adjusted.

As 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, for example, classification can be performed by 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 color toner and a magnetic carrier, the mixing ratio is 2 to 15% by mass, preferably 3% by mass, as the toner concentration in the developer.
Good results are usually obtained when the content is from 13 to 13% by mass, more preferably from 4 to 10% by mass. 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 is 20
~80Am are preferred of ^{2 / kg (emu / g)} .

The measurement of the magnetic properties of the carrier is performed as follows. As the apparatus, a BHU-60 type magnetization measurement apparatus (manufactured by RIKEN) can be used. About 1.0 g of a measurement sample is weighed, packed in a cell having an inner diameter of 7 mm and a height of 10 mm, and set in the device. 238.8 kA / m (3000 Oersted) at the maximum by gradually applying the applied magnetic field
To change. Next, the applied magnetic field is caused to decrease, and finally a hysteresis curve of the sample is obtained on the recording paper. From this, the saturation magnetization is determined. Note that the saturation magnetization of the magnetic carrier can be adjusted according to the constituent materials and manufacturing conditions.

(B) Black Toner As the black pigment used in the black toner, black magnetic particles can be used, and magnetite is particularly preferable. To prepare the black toner according to the present invention, a pigment or dye as a colorant, magnetic particles, a charge control agent, other control agents, and the like are added to the binder resin, if necessary, and mixed with a ball mill or the like. After mixing thoroughly, using a hot kneader such as a heating roll, kneader, or extruder, melt or knead the resin to melt the resins together, disperse or dissolve the pigment or dye, and cool. After solidification, pulverization and strict classification are performed to obtain the toner particles according to the present invention.

When the amount of unfixed toner (M / S) is M / S = 0.
In order to obtain a black toner having a coloring power in which the image density (D0.5Bk) after fixing once at 0.5 mg / cm ² is usually 0.5 to 1.5, it is necessary to use a coloring agent and magnetic particles. What is necessary is just to adjust the addition amount.

The weight average particle diameter of the magnetic one-component black toner of the present invention is 4.0 to 4.0 as in the case of the color toner.
10.0 μm, preferably 5.0 to 9.0 μm is good.
If the weight average particle size is smaller than 4.0 μm, the toner is partially overcharged by three, and a uniform coat is impaired, so that the image quality deteriorates. Further, due to the presence of the excessively charged particles in the lower layer of the sleeve, the triboelectric charging of other particles is inhibited, and it is impossible to faithfully respond to the developing electric field, and as a result, white background fog occurs. This phenomenon is remarkable in a low-humidity environment where the charge of the toner is high. On the other hand, if the weight average particle diameter is larger than 10.0 μm, the dot reproducibility is undesirably reduced. In a particularly preferred embodiment, the weight average particle size of the yellow, magenta, and cyan color toners is preferably within a range of 2.0 μm or less. This is due to the high frequency of use for black and white images,
Those having a large particle size with high durability stability of transfer and fixing are preferable. However, if it is too large, it is not desirable because the dot reproducibility of a single black color is inferior and the balance of image quality with a color image is greatly different. For this reason, it is preferable that the diameter is larger than the color toner particle diameter within a range of 2.0 μm or less.

The negatively chargeable charge control agent used for the black toner in the present invention is not limited to those usable for two-component color toners, and is not limited by the color of the material itself. All agents can be used. In particular, an azo-based metal compound is preferable because it gives good charging characteristics.

Examples of the binder resin used for the black toner include the same resins as those used for the color toner. It is also preferable to include a release agent used for the color toner.

As the magnetic material contained in the black toner of the present invention, known materials can be used. Particularly preferred magnetic materials are iron tetroxide (Fe ₃ O ₄ ) or γ-iron sesquioxide (γ-Fe ₂ O ₃ ).

The magnetic characteristics of the magnetic particles of the black toner according to the present invention are such that the saturation magnetization at 796 kA / m is 50-1.
00 Am ² / kg, preferably 65-90 Am ² / kg
And the residual magnetization is ² to 30 Am ² / kg, preferably 4 to 20 Am ² / kg. 5 saturation magnetization
If it is less than 0 Am ² / kg, the magnetic regulation force from the sleeve cannot be received, so that fogging to the non-image portion tends to increase. On the other hand, if the saturation magnetization is larger than 100 Am ² / kg, on the contrary, the magnetic regulation force from the sleeve becomes too large, so that it becomes difficult for the toner to fly to the latent image carrier, and as a result, the image density tends to be reduced. Not preferred.
Further, when the residual magnetization 2Am ² / kg less than is problematic because the fog is increased to the non-image portion, conversely, if the residual magnetization is greater than 30 Am ² / kg, the
This is not preferable because toner agglomeration in the developing device is large, mixing property after toner replenishment becomes insufficient, and image density decreases.

In the present invention, the content of the magnetic particles in the black toner is 50 to 1 with respect to 100 parts by mass of the binder resin.
30 parts by mass, preferably 60 to 110 parts by mass.
If the amount is less than 50 parts by mass, the magnetic regulation force from the sleeve is weakened, so that fog is likely to be deteriorated. In addition, uniform coatability on the sleeve also poses a problem. Conversely, when the amount is more than 130 parts by mass, the magnetic binding force is too strong, and it is difficult to obtain a sufficient image density, which is not preferable.

In order to sufficiently exhibit the characteristics of the black toner in the present invention, it is preferable to use an inorganic fine powder such as the above-mentioned fluidity improver as an external additive. In particular, it is preferable to use two kinds of inorganic fine powders in order to improve the charging property, the lubrication of the drum, and the polishing property.

As one of the inorganic fine powders (hereinafter referred to as inorganic fine powder (A)), a fluidity improver such as silica, titanium oxide, and alumina is preferable. Among them, silica is best for improving the chargeability. The content in the toner is 0.3 to 1.8 parts by mass, preferably 0.5 to 1.8 parts by mass.
1.3 parts by mass is good. If the amount is less than 0.3 parts by mass, the fluidity of the toner becomes insufficient, and good charging characteristics cannot be obtained, so that problems such as a decrease in image density and generation of fog occur. On the other hand, if the amount is more than 1.8 parts by mass, excessive charging in a low humidity environment due to the high chargeability of the inorganic fine powder is caused, the uniform coating property on the sleeve is impaired, and the image quality deteriorates. It is not preferable because fog is deteriorated. The average particle diameter of the inorganic fine powder (A) is preferably 0.001 to 0.2 μm.

Further, as another type of inorganic fine powder (hereinafter referred to as inorganic fine powder (B)), silicon, titanium, strontium, and the like can be used from the viewpoints of lubrication of the drum, abrasion, and prevention of excessive charging of the developing sleeve. A composite metal compound selected from metals such as manganese, zinc, cobalt, nickel, cerium, aluminum, barium, calcium, and zirconium is preferred. Among them, strontium titanate is desirable. Weight average particle size D of inorganic fine powder (B)
4 is 0.4 to 5 μm, preferably 0.7 to 3 μm. If it is smaller than 0.4 μm, the inorganic fine powder (B) accumulates on the lower layer of the sleeve and prevents the toner from being excessively charged, but on the contrary, it impairs the chargeability of the toner and causes fog in a low humidity environment. . Conversely, if it is larger than 5 μm, the effect of preventing the toner from being excessively charged in a low-humidity environment cannot be suitably exerted, and the uniform coatability of the sleeve is impaired, and fogging occurs. In addition, inorganic fine powder (B)
Is from 0.1 to 5 parts by mass, preferably from 0.5 to 5 parts by mass.
4 parts by mass is good. When the amount is less than 0.1 part by mass, the image density is low, the uniform coating property of the sleeve in a low humidity environment is lost, and the image flow in a high humidity environment is also easily generated. Conversely, when the amount is more than 5 parts by mass, the chargeability of the toner is hindered and fog in a low humidity environment increases, which is not preferable. <4> 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.

[0201]

[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. In brief, the principle of the measurement is as follows. When a laser beam is irradiated from a laser light source onto a measurement particle, a diffraction image is formed on the lens focal plane on the opposite side of the laser light source, and the diffraction image is detected by a detector and arithmetically processed. Thereby, the particle size distribution of the measurement particles is measured. (3) 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 measuring device (DSC measuring device) and 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 of 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. The glass transition temperature of the toner can be measured in the same manner. (4) Measuring method of toner softening point temperature The softening point temperature is measured by, 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 flowed out by 50% by volume was determined, and this was defined as the softening point temperature Tm of the resin. 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 ) (5) Method of measuring molecular weight of binder resin Mn, Mw and Mw / Mn of binder resin are gel permeates. It can be measured by application 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.

[0209] The sample is placed in THF, left for several hours, shaken sufficiently, mixed well with THF (until the sample is no longer united), and left 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. (6) Method for measuring acid value The acid value can be measured as follows.

[0210] 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 (ml number) × N × 56.1 / Sample weight (where N is a factor of N / 10 KOH) (7) Measurement method of D0.5 5 mg / cm ²
So that, you adjust the contrast potential, other development conditions of the body. 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. (8) Method for Measuring Magnetic Properties of Magnetic Particles The magnetic properties of the magnetic fine particles in the present invention can be measured using VSMP-1 manufactured by Toei Industry Co., Ltd. In measuring the magnetic properties, the magnetic fine particles weigh 0.1 to 0.15 g.
Is precisely weighed with a direct balance having a sensitivity of about 1 mg to obtain a sample, and the measurement is performed at a temperature of about 25 ° C. The external magnetic field at the time of measuring the magnetic characteristics is set to 79.58 kA / m (1 k Oersted), and the sweep speed for drawing a hysteresis loop is set to 10 minutes.

[0211]

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 photoreceptor was prepared under the conditions shown in Table 2 and a negatively charged photoreceptor was prepared under the conditions shown in Table 3.

The photoreceptor produced by the method shown in Table 2 was 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 by the method shown in Table 3 using a 0 mm aluminum cylinder.

[0214]

[Table 2]

[0215]

[Table 3] (2) Preparation of OPC Photoconductor (2-1) Preparation of OPC Photoconductor 1 First, a paint for a conductive layer was prepared by the following procedure. 10%
50 parts by mass of conductive titanium oxide powder coated with tin oxide containing antimony oxide, 25 parts by mass of phenol resin, 20 parts by mass of methyl cellosolve, 5 parts by mass of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer , Average molecular weight 3000) 0.0
02 parts by mass were dispersed and prepared for 2 hours by a sand mill using glass beads having a diameter of 1 mm. This paint has a diameter of 6
It was applied on a 0 mm mirror-finished aluminum cylinder by a dip coating method, and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.

Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts by weight of methanol to prepare a coating for an intermediate layer. This paint was applied on the conductive layer by a dip coating method and dried at 100 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.6 μm.

Next, CuKα characteristic X-ray diffraction Bragg angles (2θ ± 0.2 °) of 9.0 °, 14.2 °, 23.9 °
3 parts by mass of oxytitanium phthalocyanine having strong peaks at 0 ° and 27.1 °, 2 parts by mass of polyvinyl butyral resin and 35 parts by mass of cyclohexanone were 1 m in diameter.
m for 2 hours using a sand mill using glass beads, and then 60 parts by mass of ethyl acetate was added to obtain a paint for a charge generation layer. This paint was applied on the intermediate layer by a dip coating method, dried at 90 ° C. for 10 minutes,
A charge generation layer having a thickness of 0.2 μm was formed.

Next, 10 parts by mass of a styryl compound represented by the following formula (5) and 10 parts by mass of a polycarbonate resin (trade name Europyrone Z-800, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were mixed with 30 parts by mass of chlorobenzene and dichloromethane. The coating solution prepared by dissolving in a solvent was dip-coated on the charge generation layer and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 15 μm.

[0219]

Embedded image Thus, a negatively charged OPC photosensitive member was produced. This photoconductor is referred to as “OPC photoconductor 1”. (2-2) Preparation of OPC Photoconductor 2 Next, using the same material as used in manufacturing the OPC photoconductor 1,
A conductive layer, an intermediate layer, a charge transport layer, and a charge generation layer were laminated on an aluminum cylinder, and a surface protective layer was further laminated to prepare a positively charged OPC photosensitive member 2. The surface protective layer was prepared as follows. Antimony-containing tin oxide fine particles having an average particle size of 0.02 μm (trade name: T-1, manufactured by Mitsubishi Materials Corporation)
100 parts by mass, (3,3,3-trifluoropropyl)
After milling 30 parts by mass of trimethoxysilane (trade name LS-1090, manufactured by Shin-Etsu Chemical Co., Ltd.) and 300 parts by mass of a 95% ethanol-5% aqueous solution, the solution is filtered, washed with ethanol, and dried. Surface treatment of the tin oxide fine particles was performed by heat treatment at 120 ° C. for 1 hour. A binder resin 10 represented by the following formula (6) is added to the surface-treated tin oxide fine particles.
0 parts by mass, 30 parts by mass of a photopolymerization initiator represented by the following formula (7), and 300 parts by mass of ethanol were mixed and dispersed by a sand mill for 96 hours to prepare a coating solution for a protective layer.

[0220]

Embedded image

[0221]

Embedded image This coating solution was applied on the charge generation layer by a dip coating method, and was irradiated with ultraviolet light at a light intensity of 500 mW / cm ² for 30 seconds using a metal halide lamp to form a protective layer having a thickness of 3 μm. I got In addition, diameter 15, 2
OPC photoconductors 3 to 7 were prepared using the same method as OPC photoconductor 1 using aluminum cylinders of 0, 40, 80, and 100 mm. (3) Preparation of Toner Using the binder resin shown in Table 4 , each toner was prepared as follows. (3-1) Preparation of Yellow Toner Y1 The yellow toner was prepared as follows. -70 parts by mass of polyester resin (1)-100 parts by mass of paste pigment (C.I. Pigment Yellow 180 is produced by a known method. That is, water is removed to some extent from the pigment slurry before the filtration step. Paste pigment of 30% by mass (the remaining 70% by mass is water), which is obtained without passing through the drying step once. First, the above-mentioned raw materials are charged into a kneader-type mixer according to the above-mentioned formulation, and then added without mixing. Raise the temperature under pressure. Maximum temperature (necessarily determined by the boiling point of the solvent in the paste)
In this case, the pigment in the aqueous phase is distributed or transferred to the molten resin phase when the temperature reaches about 90 ° C to 100 ° C. After confirming this, the mixture is heated and melted and kneaded for another 30 minutes to sufficiently remove the pigment in the paste. Move to After that, once the mixer was stopped and the hot water was discharged, the temperature was further raised to 130 ° C., and the mixture was heated and kneaded for about 30 minutes to disperse the pigment and distill off the water. After cooling, the kneaded material was taken out. The water content of the final kneaded product was about 0.8% by mass. 20.0 parts by mass of the kneaded product (30% by mass of pigment particles) 86.0 parts by mass of polyester resin (1) 8 parts by mass of aluminum compound of di-tert-butylsalicylic acid 4.0 parts by mass The above formulation is sufficient. Premixed with a Henschel mixer, melt-kneaded at a temperature of 120 ° C with a twin-screw extruder, cooled, coarsely crushed using a hammer mill to about 1-2 mm, and then finely crushed by an air jet method. To a particle size of 40 μm or less. Furthermore, the obtained finely pulverized product was classified, and the weight average diameter in the particle size distribution was 8.
0 μm to obtain yellow toner particles (classified product), and for the purpose of improving fluidity and imparting charging characteristics, apply titanium oxide fine powder hydrophobized with a Si-based compound to 100 parts by mass of yellow toner particles. 1.0 parts by mass of an external additive was added to obtain a yellow toner Y1. (3-2) Preparation of Yellow Toners Y2 to Y12 Yellow toners Y2 to Y12 were prepared in the same manner except that the types of pigments and the amounts of the pigments were changed. (3-3) Preparation of Yellow Toners Y13 to Y16 Yellow toners Y13 to Y16 having different toner particle sizes were obtained in substantially the same manner as the yellow toner Y1, while changing the pulverization and classification conditions and the amount of external additives. (3-4) Preparation of Yellow Toner Y17 Except that the binder resin (9) was used instead of the binder resin (1) used for the yellow toner Y1, the rest was the same as the yellow toner Y17. I got

Table 5 shows the materials and physical properties used for each yellow toner.

[0223]

[Table 4]

[0224]

[Table 5] (3-5) Preparation of Magenta Toners M1 to M16 The first kneaded product was obtained in substantially the same manner as the yellow toner Y1, that is, using the paste pigments of the magenta pigments shown in Table 6, and the desired pigment was obtained. The resulting mixture was diluted and kneaded so as to obtain contents, thereby obtaining magenta toners M1 to M16 having a weight average diameter of 7 to 7.5 μm. (3-6) Preparation of Magenta Toner M17 A magenta toner M17 was obtained in the same manner except that the resin (9) was used instead of the resin (1) used in the magenta toner M1.

[0225]

[Table 6] (3-7) Preparation of Cyan Toners C1 to C4 In a similar manner to the yellow toner Y1, using the paste pigments of the cyan materials shown in Table 7, a first kneaded product was obtained, and then the desired pigment content was obtained. Were diluted and kneaded so as to obtain cyan toners C1 and C2 each having a weight average particle diameter of 6.0 to 8.0 μm, and C3 and C4 by changing external additives from titanium oxide A to alumina A. (3-8) Preparation of Cyan Toners C5 to C7 Instead of the charge control agent used for the cyan toner C1,
A chromium compound of tertiary butyl salicylic acid, a zirconium compound of di-tert-butyl salicylic acid, n
The same procedure was followed except that an aluminum compound of octylsalicylic acid was used.
5-C7 was obtained. (3-9) Preparation of Cyan Toners C8 to C14 Instead of the binder resin (1) used for the cyan toner C1,
Cyan toners C8 to C14 were obtained in the same manner except that binder resins (2) to (7) and binder resin (9) were used.

[0226]

[Table 7] (3-10) Preparation of Black Toner Bk1 A black toner was prepared as follows. 100 parts by mass of polyester resin (9) 85 parts by mass of magnetic particles (a) 0.3 parts by mass of aluminum compound of di-tert-butylsalicylic acid 1.5 parts by mass of azo-based iron compound 5 parts by mass of low molecular weight polypropylene The above raw materials were sufficiently premixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, and the black toner Bk1 was obtained in substantially the same manner as the yellow toner Y1. The physical properties of the magnetic particles and the external additives used are shown in Tables 8 to 1.
Table 11 shows the physical properties of the obtained toner.

[0227]

[Table 8]

[0228]

[Table 9]

[0229]

[Table 10]

[0230]

[Table 11] (3-11) Preparation of Black Toner Bk2 Except for using the polyester resin (10) and the magnetic particles (b), the same procedure as in the black toner Bk1 was performed.
Black toner Bk2 was obtained. (3-12) Preparation of Black Toners Bk3 to Bk5 Except for using magnetic particles (c) to (e) instead of magnetic particles (a) used in black toner Bk1, the rest is the same. , Black toner Bk3 to Bk5
I got (3-13) Preparation of Black Toner Bk6 A black toner Bk6 was obtained in substantially the same manner as the black toner Bk1, except that the polyester resin (8) and the magnetic particles (f) were used. (3-14) Preparation of Black Toner Bk7 A black toner Bk7 was obtained in substantially the same manner as the black toner Bk1 except that the polyester resin (1) and the magnetic particles (g) were used. (3-15) Preparation of Black Toner Bk8 A black toner Bk8 was obtained in substantially the same manner as the black toner Bk1 except that the polyester resin (7) and the magnetic particles (h) were used. (3-16) Preparation of Black Toner Bk9 Except for using the polyester resin (11) and the magnetic particles (i), the black toner Bk9 was prepared in substantially the same manner as the black toner Bk1.
Black toner Bk9 was obtained. (3-17) Preparation of Black Toner Bk10 A black toner Bk10 was obtained in substantially the same manner as the black toner Bk1, except that the polyester resin (9) and the magnetic particles (nu) were used. (3-18) Preparation of Black Toner Bk11 Black toner Bk11 was prepared in substantially the same manner as black toner Bk1 except that 60 parts by mass of magnetic particles (a) were added.
k11 was obtained. (3-19) Preparation of Black Toner Bk12 A black toner Bk12 was obtained in substantially the same manner as the black toner Bk1, except that 100 parts by mass of the magnetic particles (a) were added. (3-20) Preparation of Black Toner Bk13 A black toner Bk13 was obtained in substantially the same manner as the black toner Bk1, except that 5.0 parts by mass of an aluminum compound of di-tert-butylsalicylic acid was added. (3-21) Preparation of Black Toner Bk14 A black toner Bk14 was obtained in substantially the same manner as the black toner Bk1 except that 120 parts by mass of the magnetic particles (a) were added. (3-22) Preparation of Black Toner Bk15 The black toner Bk15 was prepared in substantially the same manner as the black toner Bk1, except that 130 parts by mass of the magnetic particles (a) were added and the aluminum compound of di-tert-butylsalicylic acid was not added. Bk15 was obtained. (4) Preparation of carrier and developer Mn-Mg-Fe-based ferrite is used as a core agent, and a nitrogen-containing silane coupling agent and a modified silicone resin formed of a silicone resin are coated at about 0.2% by mass to form a two-component developer. A carrier (carrier 1) was produced. The 50% volume average particle size of the carrier 1 was 40 μm.

Next, the kind of the core agent, the coating agent, and the particle size were changed.
Carriers 2 to 7 were produced. Table 12 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 color toner obtained above so that the total amount becomes 100 parts by mass to prepare a two-component developer.

[0233]

[Table 12] <Experimental example 1> The black station described above had a diameter of 1
A negatively charged a-Si photosensitive member (2 to 2) prepared in the same manner as the negatively charged a-Si photosensitive member 2 using an aluminum cylinder having a mirror finish of 5, 20, 60, 80, and 100 mm
4, 6, 7), and the color station has a diameter of 1
The negatively-charged OPC photoconductors (1, 3, 4,...) Prepared in the same manner as the negatively-charged OPC photoconductor 1 using an aluminum cylinder having a mirror finish of 5, 20, 60, 80, and 100 mm
6 and 7), which have the same structure as the image forming apparatus shown in FIG. 1 of the above embodiment and produce full-color images of four colors including charging, exposure, development, transfer, cleaning, and charge removal. The images were evaluated with a possible experimental device.

The first image forming unit uses yellow toner, the second image forming unit uses magenta toner, and the third image forming unit uses magenta toner.
The cyan toner is arranged in the image forming unit and the magnetic black toner is arranged in the fourth image forming unit. The peripheral speed (process speed) of the photoreceptor is set to 200 mm / s, the surface potential of the photoreceptor is set to -350 V in the developing region, the distance between the photosensitive drum and the developing sleeve is 400 μm, and the developing sleeve is twice the peripheral speed of the photoreceptor. It rotates at the speed. 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. Carrier 1 was used as a carrier.

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 13 shows the results.

[0237]

[Table 13] When a photoconductor having a diameter of 15 mm was used, the surface potential of the a-Si photoconductor of 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 a photoreceptor 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 density of the image generated by the first image forming unit was reduced. It 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> Experimental apparatus used in Experimental Example 1 and diameter of 60 m
An image was formed in the same manner as in Experimental Example 1 using m-a-Si photosensitive member 2. The charging potential was changed from 200 to 500 V, and the image density and the reflection density were 0.6, and the reflection density was 0.6.
The density difference after one rotation between the exposed portion and the specific exposed portion, which is called a ghost, was examined. Table 14 shows the results.

[0239]

[Table 14] When the absolute value of 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.

Similarly, the 60 mm diameter O
When the test was performed on the PC photoreceptor 1, a good image was obtained under the condition of an absolute value of the surface potential of 500 V to 800 V. Table 15 shows the results.

[Table 15] <Experimental Example 3> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
Using the a-Si photoconductor 2 of m, the dependence of the minimum gap (SD gap) between the photoconductor and the developing sleeve was evaluated. The SD gap is changed from 300 to 900 μm for the first, second, and third image forming units, and is changed from 80 to 530 μm for the fourth image forming unit. The fusion and density of the photoreceptor when 10,000 images were printed were examined. Table 16 shows the results.

[0241]

[Table 16] When the SD gap was smaller than 350 μm in the a-Si photosensitive member, drum fusion occurred. On the other hand, when it was larger than 800 μm, a sufficient image density could not be obtained.

Similarly, when the test was carried out for the OPC photosensitive member 1, good images were obtained under the conditions of 350 to 800 μm. <Experimental Example 4> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
The dependence of the peripheral speed ratio of the sleeve on the OPC photosensitive member 1 and the a-Si photosensitive member 2 was evaluated. The peripheral speed of the sleeve varies from 1.05 to 5 times the peripheral speed of the photoreceptor, and the initial black image density, the image density when 50,000 sheets of 7% yellow and black originals are imaged, and on the drum Was examined for fog. Table 17 shows the results.

[0243]

[Table 17] When the sleeve peripheral speed ratio was smaller than 1.1, a decrease was observed from the initial image. When the sleeve peripheral speed ratio was greater than 4.0, the density was reduced after 50,000 sheets were run.

Further, fogging occurred and a good image could not be obtained. <Experimental Example 5> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
Using m OPC photoreceptor 1 and a-Si photoreceptor 2, the image quality dependence on the particle size of the toner was evaluated. Yellow toner Y1, Y13 to Y16 and black toner Bk
1 to 4 were used. The results are shown in Tables 18 and 19.

[0245]

[Table 18]

[0246]

[Table 19] <Experimental Example 6> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
Using the OPC photosensitive member 1 of m, the dependence on the particle size of the carrier was evaluated. The results are shown in Table 20.

[0247]

[Table 20] 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 size 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. <Experimental Example 7> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
Using the OPC photosensitive member 1 of m, the dependence of the image on the binder resin of the toner was evaluated. Using the cyan toner C1 and the cyan toners C9 to C13, the transition of the density of each resin in the initial and after 50,000 sheets in a low-temperature and low-humidity environment (initial density → the density in 50,000 sheets), and in the high-temperature and high-humidity environment The image quality and the transparency of the OHP were evaluated. The results are shown in FIG.

[0248]

[Table 21] <Experimental Example 8> Experimental apparatus used in Experimental Example 1 and a diameter of 60 m
Using the a-Si photosensitive member 1 of m, the dependence of the image on the softening point of the black toner was evaluated. Using the black toner Bk1 and the black toners Bk6 to Bk9, the cleaning property and the fixing property in a single color were evaluated. Table 2 shows the results
It is shown in FIG.

[0249]

[Table 22] The a-Si photoreceptor and the one-component black toner were preferably used at a softening point in the range of 90 to 115 ° C.

Similarly, using the experimental apparatus used in Experimental Example 1 and the OPC photosensitive member 1 having a diameter of 60 mm, the dependence of the image on the softening point of the color toner was evaluated. Using cyan toner C9, cyan toner C12, and cyan toner C14, the cleaning property and the fixing property of a single color were evaluated. O
Color softening point of PC photoreceptor has a softening point of 85 to 115 ° C.
A good image was obtained under the following conditions. The results are shown in Table 23.

[Table 23] <Experimental example 9> Experimental apparatus used in Experimental example 1 and a diameter of 60 m
Using the a-Si photosensitive member 1 of m, the dependence on the coloring power of the toner was evaluated.

The coloring power of the toner is as follows: when the amount of unfixed toner (M / S) on the transfer material is M / S = 0.5 mg / cm ² , the image density (D0.5) after normal fixing once. Was evaluated.
Using black toners Bk3, Bk5 and Bk11 to Bk15 having different coloring powers for the black toner,
Images of 16 gradations were produced with each toner, and the density and gradation were evaluated. The results are shown in Table 24.

[0252]

[Table 24] As shown in Table 24, when D0.5 is small, a sufficient image density cannot be obtained. When D0.5 is larger than 1.5,
There was a problem in the reproducibility of the density of the intermediate colors due to environmental changes.

[0253]

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 disposed in the image forming unit, the black toner is disposed in the fourth image forming unit, the negatively charged OPC photosensitive member 1 is disposed in the color station, and the negatively charged a-Si photosensitive member is disposed in the black station. 2 was arranged. The peripheral speed (process speed: PS) of the photoconductor is 133
It was rotated at mm / s. The surface potential of the a-Si photosensitive member was set to -400 V in the developing region, and the surface potential of the OPC photosensitive member was set to -700 V. The distance between the photosensitive drum and the developing sleeve was 450 μm, and the developing sleeve was rotated at a speed of 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.

As the toner, Y1 was used for the yellow toner, M1 for the magenta toner, C1 for the cyan toner, and Bk1 for the black toner. Carrier 1 was used as a carrier.

Table 25 shows the difference in the softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0257]

[Table 25] <Experimental example 10> Using the image forming apparatus used in Example 1,
Except that the yellow toner Y17, the magenta toner M17, the cyan toner C14, and the black toner Bk1 were used, a full-color image was formed by changing the fixing temperature in the same manner as in Example 1. When the fixing temperature was high, a good image was obtained, but when the fixing temperature was lowered, there was a problem in the color mixing of the color toner.

In the case of the toner used in Example 1, there was no problem in the low-temperature fixability, and a good image was obtained. Therefore, the softening point of the color toner is
It has been found that lowering by 5 degrees or more is effective.

[0259]

[Embodiment 2] OPC photoconductor 5
The image evaluation was performed using the same image forming apparatus as in Example 1 except that the a-Si photosensitive member 5 was arranged in the black station. Circumferential speed of photoconductor (Process speed: P
S) was set to 100 mm / s, the surface potential of the a-Si photosensitive member was set to −320 V in the development area, and the OPC photosensitive member was set to −320 V.
It was set to 650V. The distance between the photosensitive member of the color station and the developing sleeve was 600 μm, the distance between the photosensitive member of the black station and the developing sleeve was 400 μm, and the developing sleeve 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. The toner used was Y2 for the yellow toner, M2 for the magenta toner, C2 for the cyan toner, and black toner Bk1. Carrier 6 was used as a carrier.

Table 25 shows the difference in the softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0261]

[Embodiment 3] The OPC photosensitive member 1 is installed in the color station.
The image evaluation was performed using the same image forming apparatus as in Example 1 except that the a-Si photosensitive member 2 was arranged in the black station.

Peripheral speed of photosensitive member (process speed: PS)
Is 300mm / s for black and white printing and 200mm / s for color printing
s. The surface potential of the a-Si photoreceptor was set at -380 V in the development area, and the surface potential of the OPC photoreceptor was set at -550 V.

The distance between the photosensitive drum and the developing sleeve is 450
μm, the developing sleeve rotated at a speed three times the peripheral speed of the photoreceptor. An image forming apparatus capable of forming 70 black and white images and 45 color images per minute by image exposure was used. The toner used was Y3 for the yellow toner, M3 for the magenta toner, C3 for the cyan toner, and Bk1 for the black toner. Carrier 7 was used as a carrier.

Table 25 shows the difference in softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0265]

Embodiments 4 to 14 The yellow toner Y1 was changed to Y2 to Y12.
The image formation was performed under the same conditions as in Example 1 except that any one of the above was changed. Table 25 shows the difference in softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0266]

Embodiments 15 to 29: Magenta toner M1 was changed to M2 to M1
Except that I changed it to any of 6. Image formation was performed under the same conditions as in Example 1. Table 25 shows the difference in softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0267]

Examples 30 to 35 An image was formed under the same conditions as in Example 1 except that the cyan toner C1 was changed to any one of C2 to C7. Table 25 shows the difference in softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0268]

Embodiments 36-49 The black toner Bk1 was replaced with Bk2-
Image formation was performed under the same conditions as in Example 1 except that any one of Bk15 was used. Table 25 shows the difference in softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0269]

Comparative Example 1 An image was formed under the same conditions as in Example 1 except that the yellow toner Y1 was changed to Y17. Table 25 shows the difference in the softening point of the toner, the coloring power of the black toner, and the evaluation results.
Shown in

[0270]

Comparative Example 2 An image was formed under the same conditions as in Example 1 except that the magenta toner M1 was changed to M17. Table 25 shows the difference in the softening point of the toner, the coloring power of the black toner, and the evaluation results.
Shown in

[0271]

Comparative Example 3 An image was formed under the same conditions as in Example 1 except that the cyan toner C1 was changed to C14. Table 25 shows the difference in softening point of toner, coloring power of black toner, and evaluation results.
Shown in

[0272]

Embodiment 50 The OPC photosensitive member 2 is provided in the color station.
The image evaluation was performed using the same image forming apparatus as in Example 1 except that the a-Si photosensitive member 1 was arranged in the black station.

Circumferential speed of photosensitive member (process speed: PS)
Was set to 200 mm / s. The surface potential of the a-Si photosensitive member was set to 380 V in the developing region, and 650 V for the OPC photosensitive member. The distance between the photosensitive member and the developing sleeve was 500 μm, and the developing sleeve rotated at a speed 1.9 times the peripheral speed of the photosensitive member. An image forming apparatus capable of forming 50 images per minute using back scan exposure for image formation was manufactured. The toner is Y1 for yellow toner, M1 for magenta toner, C1 for cyan toner, and black toner Bk.
1 was used. Carrier 1 was used as a carrier.

Table 25 shows the difference in the softening point of the toner, the coloring power of the black toner, and the evaluation results.

[0275]

According to the present invention, a black-and-white image having high productivity, high durability and high stability and a high image quality having excellent productivity and stability are provided.
A full-color image forming method and apparatus capable of obtaining a high-quality full-color image can be provided.

[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, second, and third image forming units of the image forming apparatus of the present invention.

FIG. 6 is a schematic diagram illustrating a fourth image forming unit of the image forming apparatus of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 3 developing sleeve 4 photoreceptor 5 developer reservoir 9 developing device 10 magnet 11, 12 stirring screw 13 developing chamber 14 stirring substance 15 power supply 21 charging device 22 light emitting element 23 transfer charging device 24 transfer paper 25 fixing device 26 cleaning device B photosensitive Body 2E Developing device 21E Developing container 23E Magnetic roller 24E Doctor blade 27E Stirring member of stirring chamber in developing container TE Toner in developing container T1E Toner on sleeve T2E Toner on photoconductor S0E Alternating bias voltage applying means S1E Development area αE Photoconductor and sleeve 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 volume 2112,3112 cylindrical support 2113,3113 support overheated heater 2114 source gas inlet pipe 2115 high-frequency matching box 2200 material gas feed system 3130 discharge space

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/08 G03G 5/08 9/083 9/10 9/087 15/08 503A 9/09 506A 9 / 10 507H 15/08 503 9/08 101 506 361 507 331 (72) Inventor Katsumi Kondo 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Makoto Shinbayashi 3 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inside the inventor Takaaki Uetaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yuji 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Corporation F term (reference) 2H005 AA01 AA21 CA08 CA21 CA22 EA03 EA05 FA02 FA06 2H030 AA03 AB02 AD01 BB33 BB44 BB63 BB71 2H068 AA21 DA00 FC02 2H077 AB02 A C02 AD02 AD06 AD24 AE06 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 forming in the first image forming unit includes (i) a first charging step of charging a first photoconductor having an organic photoconductive layer, a first exposing step, and a first developing sleeve. And (ii) the first photoreceptor 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 500 to 800 V in the first charging step, and then the electrostatic image is formed by the exposure in the first exposure step. (Iii) in the first developing step, the two-component developer containing the first toner and the first magnetic carrier forms a magnetic brush on the first developing sleeve, and (iv) the first developing sleeve. And the first developing sleeve is arranged such that the minimum gap is 350 to 800 μm, and (v) the first developing sleeve has a peripheral speed of 1.1 to 1.1 μm of the first photosensitive member. While rotating at a peripheral speed of 4.0 times, the first electrostatic image is developed with a magnetic brush of a two-component developer to form a first toner image on the first photoconductor, and (B)
The second image forming in the second image forming unit is
(I) including at least a second charging step of charging a second photoconductor having an organic photoconductive layer, a second exposing step, and a second developing step using a second developing sleeve;
The 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 500 to 800 V in the second charging step, the photosensitive member is exposed to light in the second exposure step. (Iii) in the second developing step, a two-component developer containing the second toner and the second magnetic carrier is formed on the second developing sleeve. A magnetic brush is formed, and (iv) a minimum gap between the second photosensitive member and the second developing sleeve is 35 mm.
(V) the second developing sleeve has a peripheral speed of 1.1 to 1.1 μm of the second photosensitive member.
While rotating at a peripheral speed of 4.0 times, the second electrostatic image is developed by a magnetic brush of a two-component developer to form a second toner image on the second photosensitive member. The third image formation in the third image forming unit includes (i) a third charging step of charging a third photoconductor having an organic photoconductive layer,
And (iii) the third photoconductor has a diameter of 20 mm.
-80 mm, and the developing area of the photoconductor facing the developing sleeve in the third charging step is 500-80 in absolute value.
After being charged to 0 V, a third electrostatic image is formed on the third photoconductor by exposure in a third exposure step, and (iii)
In the third developing step, the two-component developer containing the third toner and the third magnetic carrier forms a magnetic brush on the third developing sleeve, and (iv) the third photosensitive member and the third The developing sleeve is provided such that the minimum gap is 350 to 800 μm, and (v) the third developing sleeve is
While rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the third photosensitive member, the third electrostatic image is developed by a magnetic brush of a two-component developer to form a third toner image (D) forming a fourth image on the third photoconductor, and (D) forming a fourth image in the fourth image forming unit by (i) charging the fourth photoconductor having the amorphous silicon or the amorphous silicon layer to the fourth photoconductor. Charging step, fourth exposure step, and fourth step using a fourth developing sleeve.
(Ii) the fourth photoconductor has a diameter of 20 to 80 mm, and the developing area of the photoconductor facing the developing sleeve in the fourth charging process is 30 in absolute value.
After being charged to 0 to 450 V, an electrostatic image is formed on the fourth photoconductor by a fourth exposure step. (Iii) In the fourth development step, the one-component magnetic developer containing the fourth toner is removed. (Iv) the fourth photoconductor and the fourth developing sleeve are provided so that the minimum gap is 100 to 500 μm; and (v) the fourth photoconductor is a fourth photoconductor. Developing a fourth electrostatic image with a one-component magnetic developer while rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of to form a fourth toner image on a fourth photoconductor; (E) The first toner, the second toner, and the third toner have mutually different color tones and are selected from the group consisting of nonmagnetic yellow toner, nonmagnetic magenta toner, and nonmagnetic cyan toner. , The fourth toner comprises a magnetic black toner, and (a) a non-magnetic yellow toner. Toner, non-magnetic magenta toner, non-magnetic cyan toner and the magnetic black toner has a negative chargeability, a weight average particle diameter of each toner 4.0
(B) a 50% volume average particle diameter of the magnetic carrier of the two-component developer is 10 to 80 μm;
(C) The softening point of the yellow toner is TmY, the softening point of the magenta toner is TmM, the softening point of the cyan toner is TmC,
When the softening point of the black toner is TmBk, Tm
Y, TmM, and TmC are respectively 85 to 110 ° C,
TmBk is 90 to 115 ° C., and TmBk is T
5 ° C. or higher than the maximum of mY, TmM, and TmC,
(D) The amount of unfixed toner (M / S) on the transfer material is represented by M / S =
The image density after one-time fixing at 0.5 mg / cm ² is D0.5, and the image density of the black toner (D0.
5) is D0.5Bk, D0.5Bk is 0.5
An image forming method having a coloring power of 1.5 to 1.5. 2. The non-magnetic yellow toner is CI Pigment Yellow 7.
4, 93, 97, 109, 128, 151, 154, 1
The image forming method according to claim 1, further comprising at least 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
The image forming method according to claim 1, further comprising at least a magenta pigment selected from the group consisting of 4, 187, 238, 245, and CI Pigment Red 185, 265. Method. 4. The image forming method according to claim 1, wherein the non-magnetic cyan toner contains at least a Cu-phthalocyanine pigment or an Al-phthalocyanine pigment. 5. The magnetic black toner according to claim 1, wherein the magnetic black toner contains at least magnetite.
The image forming method according to any one of the above. 6. The first to third photoreceptors are photoreceptors having a positive or negatively charged organic photoconductive layer, and the fourth photoreceptor is positively or negatively charged amorphous silicon or amorphous silicon. 2. The image forming method according to claim 1, wherein the photosensitive member has a silicon layer. 7. The first to third photoconductors have a positively charged organic photoconductive layer, and the fourth photoconductor has a positively charged amorphous silicon or an amorphous silicon layer. The image forming method according to any one of claims 1 to 5, wherein the latent image is formed by back scan exposure. 8. A photoconductor having a negatively charged organic photoconductive layer, wherein the first to third photoconductors have a negatively charged amorphous silicon or an amorphous silicon layer. The image forming method according to claim 1, wherein the latent image is formed by image exposure. 9. The method according to claim 1, wherein the first to fourth toners contain an organometallic compound, and the organometallic compound is a negative charge control agent. The image forming method as described in the above. 10. 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. 11. The image forming method according to claim 1, wherein the first to fourth toners are made of a binder resin containing polyester as a main component. 12. The polyester has an acid value of 2 to 50 m.
The image forming method according to claim 11, wherein gKOH / g is used. 13. The image forming method according to claim 1, wherein the first to fourth toners have a glass transition temperature (Tg) of 50 to 70 ° C. 14. An amount of unfixed toner on a transfer material (M / S)
Is M / S = 0.5 mg / cm ² , the image density after one-time fixing is D0.5, the image density (D0.5) of the yellow toner is D0.5Y, the image density of the magenta toner (D0 .5) is D0.5M, the image density (D0.5) of the cyan toner is D0.5C, and the image density (D0.5) of the black toner is D0.5Bk.
D0.5M and D0.5C are 1.0 to 1.8, respectively.
0.5Bk has a coloring power of 0.5 to 1.5, and the maximum value of D0.5Y, D0.5M, and D0.5C (D0.
5max) and the minimum value (D0.5min) are 0 to 0.
The image forming method according to claim 1, wherein the number is 5. 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) a first image forming unit includes (i) a first image forming unit having an organic photoconductive layer. Photoconductor, first charging means, first exposure A step, at least a first developing means having a first developing sleeve, (ii) the first photoconductor has a diameter of 20 to 80 mm, and is opposed to the developing sleeve by the first charging means. After the developing area of the photoreceptor is charged to an absolute value of 500 to 800 V, an electrostatic image is formed on the first photoreceptor by exposure by the first exposing means, and (iii) the first developing means (Ii) a two-component developer including a first toner and a first magnetic carrier, the two-component developer forming a magnetic brush on the first developing sleeve, and (iv) a first photoconductor. And the first developing sleeve are arranged such that the minimum gap is 350 to 800 μm. (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,
Developing a first electrostatic image with a magnetic brush of a two-component developer to form a first toner image on the first photoconductor;
(B) The second image forming unit comprises (i) a second photoconductor having an organic photoconductive 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 500 to 800 in absolute value.
After being charged to V, a second electrostatic image is formed on the second photoreceptor by exposure by the second exposure means, and (iii) the second developing means comprises a second toner and a second magnetic material. (Ii) having a two-component developer containing a carrier, the two-component developer forming a magnetic brush on the second developing sleeve;
The minimum gap between the second photosensitive member and the second developing sleeve is 3
(V) It is set to be 50 to 800 μm.
The second developing sleeve has a peripheral speed of 1.1 to 1.1 of the second photosensitive member.
While rotating at a peripheral speed of 4.0 times, the second electrostatic image is developed by a magnetic brush of a two-component developer to form a second toner image on the second photosensitive member. The third image forming unit includes at least (i) a third photosensitive member having an organic photoconductive layer, a third charging unit, a third exposing unit, and a third developing unit having a third developing sleeve. And (i
i) The third photoconductor has a diameter of 20 to 80 mm,
After the developing section of the photosensitive member facing the developing sleeve is charged to an absolute value of 500 to 800 V,
The third electrostatic image is changed to the third image by the exposure by the third exposure means.
(Iii) the third developing means is formed on the third photoconductor.
(Ii) forming a magnetic brush on the third developing sleeve, and (iv) forming a magnetic brush on the third photosensitive member. The third developing sleeve is set so that the minimum gap is 350 to 800 μm. (V) The third developing sleeve is 1.1 to 4.0 times the peripheral speed of the third photosensitive member. While rotating at a peripheral speed of 3, the third electrostatic image is developed by a magnetic brush of a two-component developer to form a third toner image on the third photoconductor, and (D) fourth image formation The unit includes at least (i) 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 to 80 mm, and is formed by a fourth charging means. After the developing region of the photoconductor facing the developing sleeve is charged to an absolute value of 300 to 450 V, an electrostatic image is formed on the fourth photoconductor by the fourth exposure unit, and (iii) the fourth developing process is performed. The means has a one-component magnetic developer containing a fourth toner, and (iv) a minimum gap between the fourth photosensitive member and the fourth developing sleeve is 100 to 500 μm.
m, and (v) the fourth developing sleeve is rotated by a one-component magnetic developer while rotating at a peripheral speed of 1.1 to 4.0 times the peripheral speed of the fourth photosensitive member. Developing a fourth electrostatic charge image to form a fourth toner image on a fourth photoconductor,
(E) The first toner, the second toner, and the third toner are:
The fourth toner is made of a magnetic black toner, and has a different color tone, and is selected from the group consisting of a non-magnetic yellow toner, a non-magnetic magenta toner, and a non-magnetic cyan toner; The toner, the non-magnetic magenta toner, the non-magnetic cyan toner and the magnetic black toner have a negative charge property, each of the toners has a weight average particle diameter of 4.0 to 10.0 μm, and (b) a two-component developer 50% volume average particle diameter of the magnetic carrier of 10 to 8
(C) the softening point of the yellow toner is Tm
Y, when the softening point of the magenta toner is TmM, the softening point of the cyan toner is TmC, and the softening point of the black toner is TmBk, TmY, TmM, and TmC are 85 to 1 respectively.
10 ° C., TmBk is 90 to 115 ° C., and TmBk is at least 5 ° C. higher than the maximum of TmY, TmM, and TmC. (D) Unfixed toner amount (M) on the transfer material
/ S) is M / S = 0.5 mg / cm ² , the image density after one-time fixing is D0.5, and the image density (D0.5) of the black toner is D0.5Bk. .
An image forming apparatus having a coloring power in which 5Bk is 0.5 to 1.5. 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 at least 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 method according to claim 15, further comprising at least a magenta pigment selected from the group consisting of 4, 187, 238, 245, and CI Pigment Red 185, 265. apparatus. 18. The non-magnetic cyan toner according to claim 15, wherein the non-magnetic cyan toner contains at least a Cu-phthalocyanine pigment or an Al-phthalocyanine pigment.
8. The image forming apparatus according to claim 7, 19. The magnetic black toner according to claim 15, wherein the magnetic black toner contains at least magnetite.
19. The image forming apparatus according to any one of claims 18 to 18. 20. The first to third photoconductors are photoconductors having a positive or negatively charged organic photoconductive layer, and the fourth photoconductor is positively or negatively charged amorphous silicon or amorphous silicon. The image forming apparatus according to claim 15, wherein the image forming apparatus is a photoconductor having a silicon layer. 21. A photosensitive member having a positively charged organic photoconductive layer, wherein the first to third photosensitive members have a positively charged amorphous silicon or an amorphous silicon layer. The image forming apparatus according to any one of claims 15 to 19, wherein the latent image is formed by back scan exposure. 22. A photoconductor having a negatively charged organic photoconductive layer, wherein the first to third photoconductors have a negatively charged amorphous silicon or an amorphous silicon layer. The image forming apparatus according to any one of claims 15 to 19, wherein the latent image is formed by image exposure. 23. The method according to claim 15, wherein the first to fourth toners contain an organometallic compound, and the organometallic compound is a negative charge control agent. Image forming apparatus. 24. 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. 25. The image forming apparatus according to claim 15, wherein the first to fourth toners are made of a binder resin containing polyester as a main component. 26. The polyester has an acid value of 2 to 50 m.
The image forming apparatus according to claim 25, wherein gKOH / g is used. 27. The image forming apparatus according to claim 15, wherein the first to fourth toners have a glass transition temperature (Tg) of 50 to 70 ° C. 28. Amount of unfixed toner on transfer material (M / S)
Is M / S = 0.5 mg / cm ² , the image density after one-time fixing is D0.5, the image density (D0.5) of the yellow toner is D0.5Y, the image density of the magenta toner (D0 .5) is D0.5M, the image density (D0.5) of the cyan toner is D0.5C, and the image density (D0.5) of the black toner is D0.5Bk.
D0.5M and D0.5C are 1.0 to 1.8, respectively.
0.5Bk has a coloring power of 0.5 to 1.5, and the maximum value of D0.5Y, D0.5M, and D0.5C (D0.
5max) and the minimum value (D0.5min) are 0 to 0.
The image forming apparatus according to any one of claims 15 to 27, wherein the number is 5.