JP2003270813A - Organophotoreceptor, image forming method, image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organophotoreceptor which does not cause image defects such as black spots and voids and ensures good image quality, an image forming method using the organophotoreceptor, an image forming apparatus and a process cartridge. <P>SOLUTION: The organophotoreceptor having a photosensitive layer on an electrically conductive support, is characterized in that the photosensitive layer contains charge generating materials and charge transport materials, at least one of the charge transport materials is a mixture of stereoisomers of a bis(arylethenylphenyl)aniline compound and the content of the greatest isomer component in the mixture is 40-90 mass%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic photoconductor used in the field of copying machines and printers, an image forming method using the organic photoconductor, an image forming apparatus and a process cartridge.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors (hereinafter also simply referred to as photoreceptors) are Se, arsenic, arsenic / Se alloys, CdS, ZnO.
Inorganic photoconductors such as the above have been transferred to organic photoconductors that are excellent in advantages such as pollution and ease of production, and organic photoconductors using various materials have been developed.

In recent years, function-separated type photoconductors in which different materials are responsible for charge generation and charge transport functions have become the mainstream. Among them, a laminated organic photoconductor in which a charge generation layer and a charge transport layer are laminated. Is widely used.

In addition, focusing on the electrophotographic process, latent image forming methods are roughly classified into analog image forming using a halogen lamp as a light source and digital image forming using an LED or a laser as a light source. Recently, a digital latent image forming method is rapidly becoming the mainstream as a printer for a hard copy of a personal computer, and also in an ordinary copying machine because of the ease of image processing and the ease of development to a multi-function peripheral.

In digital image formation, a laser, particularly a semiconductor laser or an LED, is used as a light source when writing image information converted into a digital electric signal on a photoreceptor as an electrostatic latent image.

In digital writing, the writing speed is slow because the exposure beam diameter is small. Therefore, a combination with reversal development is mainly used as a developing method for the exposed portion, but as a problem peculiar to the image forming method using the reversal development, toner is originally formed on a portion where an image is to be formed as a white background portion. It is known that a black spot is generated due to a local defect of the photoconductor, which is a phenomenon in which the toner adheres to cause fog.

In order to solve these problems, a technique using an intermediate layer for an organic photoconductor has been developed. For example, an electrophotographic photosensitive member is known in which an intermediate layer is provided between a conductive support and a photosensitive layer, and titanium oxide particles are dispersed in a resin in the intermediate layer. Further, a technique of an intermediate layer containing titanium oxide subjected to surface treatment is also known. For example,
JP-A-4-303846, iron oxide and titanium oxide surface-treated with tungsten oxide, JP-A-9-96916, titanium oxide surface-treated with an amino group-containing coupling agent, JP-A-9-258469, organosilicon. Titanium oxide surface-treated with a compound, titanium oxide surface-treated with methyl hydrogen polysiloxane of JP-A-8-328283, metal oxide of JP-A-11-344826, or dendritic surface-treated with an organic compound Organic photoreceptors having an intermediate layer using titanium oxide have been proposed.

However, even if these techniques are used, in a severe environment such as high temperature and high humidity, the prevention of black spots is still insufficient, or the residual potential and the exposed portion potential increase with repeated use. Occurs, and there is a problem that an image density is not sufficiently obtained.

Further, if the insulating property of the intermediate layer is increased and black spots are reduced in order to prevent free carriers from the conductive support to the photosensitive layer, an image called "white spot" which is the opposite of black spots is obtained. Problems have been found to be prone to defects.
This white spot is a halftone of reversal development or a dot-like or line-like image defect that is not developed into a black solid image. This phenomenon is that the charge does not disappear in the image-exposed portion when a latent image is formed on the organic photoconductor. It seems that a minute portion is generated, and is considered to be a phenomenon opposite to that of the black dot. In this way, in the image forming apparatus using the organic photoconductor, conflicting image defects such as black black spots on a white background and white white spots on a black background or halftone occur, and both of these image defects are solved by the organic photoconductor. Development is needed.

The present inventors have found that, in order to solve the above-mentioned black spots and white spots at the same time, conventional studies centering on the intermediate layer are not sufficient, and have reached the present invention.

[0011]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, an object of the present invention is to provide an organic photoreceptor having good potential stability and not causing image defects such as black spots and white spots. More specifically, the present invention provides an organic photoreceptor having good image quality without causing image defects such as black spots and white spots, and an image forming method, an image forming apparatus, and a process cartridge using the organic photoreceptor. Especially.

[0012]

Means for Solving the Problems The inventors of the present invention have made a study on a photosensitive layer constituting an organic photosensitive member, and as a result, by using a stereoisomer mixture as a charge transporting substance in the photosensitive layer, the problems of the present invention are solved. Found that can be solved. That is, the object of the present invention is achieved by using an organic photoreceptor having the following constitution.

The present invention will be described in detail below. 1. In an organic photoreceptor having a photosensitive layer on a conductive support, the photosensitive layer contains a charge generating substance and a charge transporting substance,
At least one of the charge-transporting substances is a stereoisomeric mixture of bis (arylethenylphenyl) aniline compounds, and the content of the maximum isomer component in the stereoisomeric mixture is 40 to 90% by mass. An organic photoconductor characterized by.

2. In an organic photoreceptor having a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer on a conductive support,
The charge transport layer is a stereoisomeric mixture of bis (arylethenylphenyl) aniline compounds, and the content of the maximum isomer component in the stereoisomeric mixture is 40 to 90% by mass.
An organophotoreceptor containing a charge transport material of

3. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (1).

4. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (2).

5. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (3).

6. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (4).

7. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (5).

8. 3. The organophotoreceptor described in 1 or 2 above, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (6).

9. 9. The organophotoreceptor according to any one of 3 to 8 above, wherein the substituted or unsubstituted aromatic group of Ar ¹ and Ar ² is the general formula (7).

10. 1 to 9 above, wherein the organic photoreceptor has an intermediate layer between a conductive support and a photosensitive layer.
The organic photoreceptor according to any one of 1.

11. 10. The intermediate layer contains N-type semiconductive fine particles and a binder resin.
The organic photoconductor according to item 1.

12. An image forming method, wherein an electrophotographic image is formed using the organic photoconductor according to any one of 1 to 11 above.

13. An image forming apparatus, wherein an electrophotographic image is formed by using the image forming method described in 12 above.

14. 12. The organic photoconductor according to any one of 1 to 11 and at least one of a charger, an image exposure device, a developing device, a transfer device, and a cleaning device are integrally provided, and can be taken in and out of an image forming apparatus. A process cartridge that is configured.

The organic photoreceptor of the present invention (hereinafter, also simply referred to as a photoreceptor) has a photosensitive layer on a conductive support, and the photosensitive layer has a charge generating substance and a charge transporting substance. At least one of them is a stereoisomer mixture of bis (arylethenylphenyl) aniline compounds, and the content of the maximum isomer component in the stereoisomer mixture is 40 to 90% by mass.

That is, the charge transport material used in the photosensitive layer is a stereoisomeric mixture of bis (arylethenylphenyl) aniline compounds, and the charge transport material having charge transport property is used. It is possible to obtain an organic photoreceptor in which image defects are prevented and which has good electrophotographic characteristics such as charging property and sensitivity. The content of the maximum component of the stereoisomer mixture must be 40 to 90% by mass. When the content of the maximum component is more than 90% by mass, the dispersibility of the charge transport material is deteriorated, which causes fog and a decrease in image density, and the sharpness is apt to be decreased. On the other hand, when the content is less than 40% by mass, the occurrence of white spots is increased, the resolution is lowered, and the stability of electrophotographic characteristics is impaired. In particular, the content of the maximum component is preferably 45 to 80% by mass.

The effect as described above is obtained by using the charge transport material of the stereoisomeric mixture of bis (arylethenylphenyl) aniline compounds to improve the compatibility between the charge transport material and the binder of the photosensitive layer. It is considered to be favorable, and it is considered that the film quality of the charge transport layer and the electrophotographic characteristics are improved.

The bis (arylethenylphenyl) aniline compound of the present invention refers to a group of compounds having two arylethenylphenyl groups having the same chemical structure at the nitrogen atom of aniline, preferably the above-mentioned general formula (1). And is preferably a compound represented by the general formula (2) to the general formula (6)
As described above, those having an alkyl group or an alkoxy group at the ortho or para position of the aniline group are preferable. less than,
Examples of preferred bis (arylethenylphenyl) aniline compounds of the present invention will be given, but the present invention is not limited to the following compound examples. Also, any of these compounds can have a stereoisomeric structure.

[0031]

[Chemical 8]

[0032]

[Chemical 9]

[0033]

[Chemical 10]

[0034]

[Chemical 11]

[0035]

[Chemical 12]

[0036]

[Chemical 13]

[0037]

[Chemical 14]

[0038]

[Chemical 15]

[0039]

[Chemical 16]

[0040]

[Chemical 17]

[0041]

[Chemical 18]

The molecular weight of the charge transport material having a stereoisomeric structure is preferably 500 or more and 1500 or less. By using such a charge transport material having a relatively high molecular weight, the film quality of the charge transport layer can be improved, and the effects of the present invention described above can be made more prominent.

The charge-transporting substance of the stereoisomer mixture means a compound of the charge-transporting substance having the same chemical structural formula and having an isomer structure caused by different configurations of atoms or atomic groups therein. .

Next, the layer structure of the organic photoconductor using the above charge transport material will be described.

The organic photoreceptor of the present invention means an electrophotographic photoreceptor composed of an organic compound having at least one of a charge generating function and a charge transporting function which are indispensable for the construction of the electrophotographic photoreceptor. All of known organic electrophotographic photoreceptors such as a photoreceptor composed of a known organic charge generating material or an organic charge transporting material, and a photoreceptor composed of a polymer complex having a charge generating function and a charge transporting function.

The constitution of the organic photoconductor used in the present invention will be described below. Conductive Support The conductive support used for the photoconductor may be either a sheet or a cylinder, but a cylindrical conductive support is preferable for compact design of the image forming apparatus. .

The cylindrical conductive support means a cylindrical support required to form an image endlessly by rotating, and has a straightness of 0.1 mm or less and a shake of 0.1 mm.
A conductive support in the following range is preferable. If the straightness and the shake range are exceeded, good image formation becomes difficult.

As the conductive material, a metal drum of aluminum, nickel or the like, a plastic drum on which aluminum, tin oxide, indium oxide or the like is deposited, or a paper / plastic drum coated with a conductive substance can be used. It is preferable that the conductive support has a specific resistance of 10 ³ Ωcm or less at room temperature.

The conductive support used in the present invention may have a surface on which a sealed alumite film is formed. The alumite treatment is usually carried out in an acidic bath of chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing treatment in sulfuric acid, it is preferable that the sulfuric acid concentration is 100 to 200 g / L, the aluminum ion concentration is 1 to 10 g / L, the liquid temperature is about 20 ° C., and the applied voltage is about 20 V. It is not limited. The average thickness of the anodized film is usually 2
It is preferably 0 μm or less, and particularly preferably 10 μm or less.

Intermediate Layer In the present invention, an intermediate layer having a barrier function can be provided between the conductive support and the photosensitive layer.

In the present invention, an intermediate layer (lower layer) is provided between the support and the photosensitive layer in order to improve the adhesion between the conductive support and the photosensitive layer or prevent charge injection from the support. (Including a pulling layer) can also be provided. Examples of the material of the intermediate layer include a polyamide resin, a vinyl chloride resin, a vinyl acetate resin, and a copolymer resin containing two or more of repeating units of these resins. Among these undercoat resins, a polyamide resin is preferable as a resin that can reduce the increase in residual potential due to repeated use. The thickness of the intermediate layer using these resins is 0.01 to 0.5 μm.
Is preferred.

The intermediate layer preferably used in the present invention includes an intermediate layer using a curable metal resin obtained by thermosetting an organic metal compound such as a silane coupling agent and a titanium coupling agent. The film thickness of the intermediate layer using the curable metal resin is preferably 0.1 to 2 μm.

The intermediate layer preferably used in the present invention includes an intermediate layer in which N-type semiconductive fine particles having a hydrophobic surface treatment are dispersed in a binder. For example, the average particle size after the silica / alumina treatment and the surface treatment with a silane compound is 0.
An intermediate layer in which titanium oxide having a thickness of 0 to 1 μm is dispersed in a polyamide resin can be mentioned. The thickness of such an intermediate layer is 1
˜20 μm is preferred.

The N-type semiconductive fine particles are fine particles having a property that the conductive carrier is an electron. That is, the property that the conductive carrier is an electron means that the N-type semiconductive fine particles are contained in the insulating binder to efficiently block the hole injection from the substrate, and the electron from the photosensitive layer is blocked. On the other hand, it refers to a substance that does not exhibit blocking properties.

Specific examples of the N-type semiconductive fine particles include fine particles of titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), etc.
Particularly, titanium oxide is preferably used.

The average particle size of the N-type semiconductive fine particles used in the present invention is 10 nm or more and 500 in number average primary particle size.
It is preferably in the range of nm or less, more preferably 10
nm to 200 nm, particularly preferably 15 nm to 50 n
m.

The number average primary particle diameter is within the above range N
The intermediate layer using the type semiconductive fine particles can have a fine dispersion in the layer, and has sufficient potential stability and a black spot generation preventing function.

In the case of titanium oxide, for example, the number average primary particle diameter of the N-type semiconductive fine particles is magnified 10,000 times by observation with a transmission electron microscope, and 100 particles are randomly observed as primary particles to obtain an image. It is measured as the number average diameter of Feret's diameter by analysis.

The N-type semiconducting fine particles used in the present invention have a dendritic, needle-like, or granular shape. The N-type semiconducting fine particles having such a shape are, for example, titanium oxide particles. As the crystal type, there are anatase type, rutile type, amorphous type, and the like, but any crystal type may be used, or two or more crystal types may be mixed and used. Among them, the rutile type is the best.

One of the hydrophobizing surface treatments performed on the N-type semiconductive fine particles of the present invention is that the surface treatment is performed a plurality of times, and the last surface treatment is reactive among the plurality of surface treatments. The surface treatment is performed with an organosilicon compound. Also,
Among the plurality of surface treatments, at least one surface treatment is at least one kind of surface treatment selected from alumina, silica, and zirconia, and the surface treatment of the reactive organosilicon compound is finally performed. preferable.

Alumina treatment, silica treatment, and zirconia treatment mean that alumina, silica, and
Alternatively, it refers to a treatment for precipitating zirconia, and the alumina, silica, and zirconia deposited on these surfaces also include hydrates of alumina, silica, and zirconia. Further, the surface treatment of the reactive organic silicon compound means that the reactive organic silicon compound is used in the treatment liquid.

In this way, the surface treatment of N-type semiconductive fine particles such as titanium oxide particles is performed at least twice, so that the surface of the N-type semiconductive fine particles is uniformly coated (treated). When the treated N-type semiconductive fine particles are used in the intermediate layer, the dispersibility of the N-type semiconductive fine particles such as titanium oxide particles in the intermediate layer is good and the image defects such as black spots are not generated. The photoconductor can be obtained.

Photosensitive Layer The photosensitive layer structure of the photoconductor of the present invention may be a photosensitive layer structure having a single layer structure in which one layer has a charge generating function and a charge transporting function on the intermediate layer, but is more preferably a photosensitive layer. It is preferable that the function of the layer is separated into a charge generation layer (CGL) and a charge transport layer (CTL). By adopting a constitution in which the functions are separated, the increase in residual potential due to repeated use can be controlled to be small, and other electrophotographic characteristics can be easily controlled according to the purpose. In the negative charging photoreceptor, the charge generation layer (C
GL) and a charge transport layer (CTL) thereon. In the case of the photoconductor for positive charging, the order of the layers is the reverse of that of the photoconductor for negative charging. The most preferable photosensitive layer structure of the present invention is a negatively charged photosensitive member structure having the above-mentioned function separation structure.

The constitution of the photosensitive layer of the function-separated negatively charged photoreceptor will be described below. Charge Generation Layer The charge generation layer contains a charge generation material (CGM). If necessary, a binder resin and other additives may be contained as other substances.

As the charge generating substance (CGM), a known charge generating substance (CGM) can be used. For example, a phthalocyanine pigment, an azo pigment, a perylene pigment, an azurenium pigment or the like can be used. Among these, CGM that can minimize the increase in residual potential with repeated use
Has a steric structure and a potential structure capable of forming a stable aggregation structure among a plurality of molecules, and specific examples thereof include a phthalocyanine pigment and a perylene pigment CGM having a specific crystal structure. For example, the Bragg angle 2θ with respect to Cu-Kα rays
CGMs such as titanyl phthalocyanine having a maximum peak at 27.2 ° and benzimidazole perylene having a maximum peak at 22.4 at 27.2 have almost no deterioration due to repeated use, and the residual potential increase can be reduced.

When a binder is used as a CGM dispersion medium in the charge generation layer, a known resin can be used as the binder, but the most preferable resin is formal resin, butyral resin, silicone resin, silicone modified butyral resin, phenoxy resin. Resin etc. are mentioned. The ratio of the binder resin to the charge generating substance is preferably 20 to 600 parts by mass with respect to 100 parts by mass of the binder resin. By using these resins, the increase in residual potential due to repeated use can be minimized. The thickness of the charge generation layer is preferably 0.01 μm to 2 μm.

Charge Transport Layer The charge transport layer contains a stereoisomer mixture as a charge transport material (CTM) and contains a binder resin for dispersing CTM to form a film. Other substances may optionally contain additives such as antioxidants.

As the charge-transporting substance (CTM), a known charge-transporting substance may be used in combination with the charge-transporting substance of the stereoisomer mixture described above. For example, triphenylamine derivative, hydrazone compound, styryl compound,
Combined use of benzidine compounds, butadiene compounds, etc.
Can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer.

Examples of the resin used for the charge transport layer (CTL) are polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd. Resins, polycarbonate resins, silicone resins, melamine resins, copolymer resins containing two or more of the repeating units of these resins, these insulating resins, and poly-
Examples include polymer organic semiconductors such as N-vinylcarbazole.

The most preferable binder for these CTLs is a polycarbonate resin. Polycarbonate resin is most preferable in improving dispersibility of CTM and electrophotographic characteristics. Further, in the case of a photoreceptor having a charge transport layer as a surface layer, a polycarbonate that is resistant to mechanical abrasion is preferable, and as such a polycarbonate, a polycarbonate having an average molecular weight of 40,000 to 25,000 is preferable. Here, the average molecular weight may be any of number average molecular weight, weight average molecular weight, and viscosity average molecular weight. The ratio of the binder resin to the charge transport material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably 10-40 μm.

Further, it is preferable that the charge transport layer contains an antioxidant. The antioxidant is a typical one that does not prevent the action of oxygen on the auto-oxidizing substance existing in the organic photoreceptor or on the surface of the organic photoreceptor under the conditions of light, heat, discharge, etc. It is a substance that has an inhibitory property. Typically, the following compounds are listed.

[0072]

[Chemical 19]

[0073]

[Chemical 20]

[0074]

[Chemical 21]

[0075]

[Chemical formula 22]

The charge transport layer may have a layer structure of two or more layers. In this case, a layer structure in which a function as a protective layer is added to the charge transport layer on the surface and abrasion resistance with a cleaning blade or the like is enhanced is preferable.

The solvent or dispersion medium used for forming the intermediate layer, the photosensitive layer, the protective layer and the like includes n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine,
N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,
1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxolane,
Dioxane, methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like can be mentioned. The present invention is not limited to these, but dichloromethane, 1,2-dichloroethane, methyl ethyl ketone and the like are preferably used. Further, these solvents can be used alone or as a mixed solvent of two or more kinds.

As the coating processing method for producing the electrophotographic photosensitive member of the present invention, coating processing methods such as dip coating, spray coating, and circular amount regulation type coating are used. Does not dissolve the lower layer as much as possible,
In order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type (a circular slide hopper type is a typical example) coating. The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount regulating coating is described in JP-A-58-1890.
This is described in detail in Japanese Patent No. 61.

Next, the image forming apparatus of the present invention will be described. FIG. 1 is a sectional configuration diagram of an image forming apparatus as an example of the image forming method of the present invention.

In FIG. 1, reference numeral 50 denotes a photosensitive drum (photosensitive member) which is an image bearing member, and an organic photosensitive layer is coated on the drum.
A photosensitive member having the resin layer of the present invention applied thereon is grounded and driven and rotated clockwise. Reference numeral 52 denotes a scorotron charger (charging means) for uniformly charging the peripheral surface of the photosensitive drum 50 by corona discharge. This charger 5
Prior to the charging by 2, the exposure may be performed by the pre-charge pre-exposure unit 51 using a light emitting diode or the like to eliminate the history of the photo conductor in the pre-image formation to eliminate the charge on the peripheral surface of the photo conductor.

After uniform charging of the photosensitive member, image exposure based on the image signal is performed by the image exposure device 53 as the image exposure means. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. Rotating polygon mirror 5
Scanning on the photosensitive drum is performed by the light whose optical path is bent by the reflection mirror 532 through the 31, f.theta.
An electrostatic latent image is formed.

Here, the reversal development process of the present invention means that the surface of the photoconductor is uniformly charged by the charger 52 to develop the image-exposed region, that is, the exposed portion potential (exposed portion region) of the photosensitive member. It is an image forming method that visualizes by a step (means). On the other hand, the unexposed portion potential is not developed by the developing bias potential applied to the developing sleeve 541.

The electrostatic latent image is then developed by the developing device 54 as a developing means. A developing device 54 containing a developer composed of toner and carrier is provided on the periphery of the photosensitive drum 50, and development is performed by a developing sleeve 541 that contains a magnet and holds the developer and rotates.
Inside the developing unit 54, the developer stirring and conveying members 544, 543,
The developer is constituted by a conveyance amount regulating member 542 and the like, and the developer is agitated and conveyed to be supplied to the developing sleeve, and the supply amount is controlled by the conveyance amount regulating member 542. The amount of the developer conveyed varies depending on the linear velocity of the applied organic electrophotographic photosensitive member and the specific gravity of the developer, but is generally 20 to 2
It is in the range of 00 mg / cm ² .

The developer is, for example, a carrier in which an insulating resin is coated around the above-mentioned ferrite core, a coloring agent such as carbon black, a charge control agent, and a low molecular weight polyolefin mainly composed of the above-mentioned styrene acrylic resin. The toner is formed by externally adding silica, titanium oxide, or the like to the colored particles made of, and the developer is transported to the developing area with the layer thickness regulated by the transport amount regulating member, and development is performed. At this time, normally, a DC bias is applied between the photosensitive drum 50 and the developing sleeve 541, and if necessary, an AC bias voltage is applied to develop. Further, the developer is developed in a state of being in contact with or non-contacting with the photoreceptor. The potential of the photoconductor is measured by providing a potential sensor 547 above the developing position as shown in FIG.

After the image formation, the recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is adjusted.

In the transfer area, a transfer electrode (transfer means: transfer device) 58 operates on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing, and the recording paper P fed is charged with a polarity opposite to that of the toner. To transfer the toner.

Then, the recording paper P is separated by a separating electrode (separator) 59.
Is discharged by the peripheral surface of the photoconductor drum 50 and conveyed to the fixing device 60. The heat roller 601 and the pressure roller 602 heat and pressurize the toner to fuse the toner, and then the paper is discharged from the outside of the device via the paper discharge roller 61. Is discharged to. The transfer electrode 58 and the separation electrode 59 stop the primary operation after passing the recording paper P and prepare for the next toner image formation. In FIG. 1, a transfer band electrode of a corotron is used as the transfer electrode 58. The setting condition of the transfer electrode varies depending on the process speed (peripheral speed) of the photoconductor and cannot be specified unconditionally. For example, the transfer current is +
100 to +400 μA, transfer voltage +500 to +
2000V can be used as the set value.

On the other hand, after the recording paper P is separated, the photosensitive drum 50 is cleaned by removing the residual toner by pressing the blade 621 of the cleaning device (cleaning means) 62.
The pre-charging pre-exposure unit 51 again removes electricity and the charger 52 charges, and the next image forming process starts.

Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charging device, a transfer device, a separator and a cleaning device are integrated.

The organic electrophotographic photosensitive member of the present invention is generally applied to electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers and liquid crystal shutter printers. It can be widely applied to devices such as printing, plate making, and facsimile.

[0091]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. In the text, "part" represents part by mass.

Example 1 Synthesis Example 1 (Synthesis Example of Exemplified Compound T20)

[0093]

[Chemical formula 23]

10 g of the compound represented by the above formula was dissolved in 32 g of phosphorus oxychloride, heated to 50 ° C., and 22 ml of dimethylformamide was added dropwise little by little (heat was generated and 40 to 40).
70 ° C). The reaction solution was stirred for 15 hours while controlling the temperature to around 90 ° C. After cooling to 40 ° C, excess phosphorus oxychloride was sufficiently hydrolyzed and the precipitated crystals were separated by filtration, suspended in water and washed, and the washing was repeated until the washing liquid became neutral. Obtained 9.25 g (77%) of the represented bisformyl compound.

[0095]

[Chemical formula 24]

2 g of the bisformyl compound obtained above,
4.3 g of the phosphonate compound represented by the following structural formula was dissolved in 20 ml of dimethylformamide. 20 reaction liquids
While maintaining the temperature around 0 ° C, 1.0 g of sodium methoxide was added little by little (heat generation). After stirring for 4 hours, water 30
After adding ml, the product was purified by a conventional method to give yellow crystals 3.3.
g (81%) was obtained. When this yellow crystal was subjected to elemental analysis and mass spectrometry, the results shown in Table 1 below were obtained, and it was confirmed that the compound was T20.

[0097]

[Chemical 25]

Elemental analysis (C ₅₃ H ₄₉ N)

[0099]

[Table 1]

Mass spectrum (C ₅₃ H ₄₉ N) Mw (calculated value) = 699 Mw ⁺ (measured value) = 699 The compound of T20 obtained by the above synthesis is designated as T20-1. This T20-1 is the following liquid chromatography (HP
CL) measurement result cis-cis / cis-trans
/ Trans-trans mixing ratio is 1.1 / 2.2 /
It was 1.0. Incidentally, T20cis-cis, T20t
The structural formulas of trans-trans and T20cis-trans are shown below.

Measurement conditions for liquid chromatography Measuring instrument: Shimadzu LC6A (manufactured by Shimadzu Corporation) Column: CLC-SIL (manufactured by Shimadzu Corporation) Detection wavelength: 290 nm Mobile phase: n-hexane / dioxane = 10-500 / 1 Flow rate of mobile phase : About 1 ml / min sample (T20) solvent: n-hexane / dioxane =
10/1 sample (T20): 3 mg / 10 ml of solvent

[0102]

[Chemical formula 26]

The T20-1 obtained above was analyzed by liquid chromatography for cis-cis form and cis-tran.
A compound separated into an s form and a trans-trans form was also obtained. T20c-c of these cis-cis bodies
T20 of the cis-trans form was replaced with T20c-t, tra
Let T20 of the ns-trans body be T20t-t. T
20-1 and T20c-c, T20c-t, T20t-t
As shown in Table 2, cis-cis / cis-trans / trans- is used by changing the mixing ratio.
Compounds T20-2 to T20-6 having a trans mixing ratio were prepared.

Preparation of Photoreceptor 1 <Intermediate Layer> Titanium oxide SMT500SAS (first: silica / alumina treatment, second: methylhydrogenpolysiloxane treatment: titanium oxide particle diameter 35 nm: manufactured by Teika) 300 parts Polyamide resin CM8000 ( (Manufactured by Toray Industries, Inc.) 100 parts Methanol 1000 parts Titanium oxide, polyamide resin, and methanol were added to the same container and dispersed using an ultrasonic homogenizer to prepare a coating liquid for the intermediate layer. This coating solution was applied onto a cylindrical aluminum substrate by dip coating, and heat-cured at 110 ° C. for 1 hour to form an intermediate layer with a dry film thickness of 4 μm.

<Charge Generation Layer> Y-type titanyl phthalocyanine (Cu-Kα characteristic X-ray has a maximum peak angle of 2θ of 27.3 at 2θ of 27.3) 60 parts Silicone-modified butyral resin (X-40-1211M: Shin-Etsu Chemical Co., Ltd.) 700 parts) 2-butanone (2000 parts) were mixed and dispersed for 10 hours using a sand mill to prepare a charge generation layer coating liquid. This coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.2 μm.

<Charge Transport Layer> Charge transport material (T20-1) 225 parts Polycarbonate (viscosity average molecular weight: 20,000) 300 parts Antioxidant (exemplary compound 1-3) 6 parts Dichloromethane 2000 parts are mixed and dissolved. Then, a charge transport layer coating solution was prepared. This coating solution was applied onto the charge generating layer by a dip coating method to form a charge transporting layer having a dry film thickness of 24 μm, to prepare a photoreceptor 1.

Preparation of Photoreceptors 2-9 The charge transport material (T20-1) used in Photoreceptor 1 was replaced with T20.
-2-T20-6, T20c-c, T20c-t, T2
Photoconductors 2 to 9 were prepared in the same manner as the photoconductor 1 except that the isomer mixture ratio was changed as shown in Table 2 instead of 0t-t.

[0108]

[Table 2]

Evaluation As an evaluation machine, a digital copying machine Konica7 manufactured by Konica
075 (having corona charging, laser exposure, reversal development, electrostatic transfer, nail separation, blade cleaning, cleaning auxiliary brush roller adoption process) was used, and photoconductors 1 to 9 were mounted on the copying machine and evaluated. For cleaning performance and image evaluation, a character image with a pixel ratio of 7%, a human face photograph,
An original image in which a solid white image and a solid black image were equally divided into quarters was copied onto A4 neutral paper. High temperature and high humidity environment (30 ° C, 80% RH) with severe environmental conditions
In both the low temperature and low humidity environment (10 ° C., 30% RH), 10,000 copies were continuously made to produce halftone, solid white images, and solid black images, and the following evaluations were performed.

Evaluation standard image density (measured using RD-918 manufactured by Macbeth Co.)
The relative reflection density was measured with the reflection density of the paper being "0".
Images were evaluated at the initial stage and after copying 10,000 sheets. ): Black solid image is 1.2 or more. ○: Black solid image is less than 1.2 to 1.0 ×: Black solid image is less than 1.0 Fog (initially and solid white image after copying 10,000 sheets is visually observed. A): No fog occurred during copying under both environmental conditions. O: Fog with a density of 0.01 to 0.02 occurred in either environment. X: Density of 0.1 in either environment. A fog of 03 or more is generated. Resolution (judgment based on easiness of distinguishing character image) After copying 10,000 sheets, a character image of 3 points and 5 points was formed and evaluated according to the following criteria.

⊚: 3 points, 5 points are clear and easily readable ○: 3 points are partially unreadable, 5 points are clear and easily readable ×: 3 points are almost unreadable, 5 Some or all of the points are unreadable black spots (after 10,000 copies were made, 100 more solid white copy images were made and evaluated) The black spots were evaluated to be A4 when a black spot with a major axis of 0.4 mm or more was A4.
It was judged based on how many pieces there were per sheet. The major axis of the black spot can be measured with a microscope equipped with a video printer. The criteria for black spot evaluation are as shown below.

A: Black spot frequency of 0.4 mm or more: All copied images are 3 pieces / A4 or less B: Black spot frequency of 0.4 mm or more: 4 pieces / A4 or more, 1
9 pieces / A4 or less occurred 1 or more C: 0.4 mm or more black spot frequency: 20 pieces / A4 or more occurred 1 or more white spots (After copying 10,000 sheets, halftone image 1
00 sheets were produced and evaluated. For evaluation of white spots, a white spot having a major axis of 0.4 mm or more was A4.
It was judged based on how many pieces there were per sheet. The blank major axis can be measured with a microscope equipped with a video printer. The criteria for evaluation of blank areas are as shown below.

A: White spot frequency of 0.4 mm or more: All copied images are 3 / A4 or less B: White spot frequency of 0.4 mm or more: 4 / A4 or more, 1
9 pieces / A4 or less occurred on 1 or more sheets C: 0.4 mm or more white spot frequency: 20 pieces / A4 or more occurred on 1 or more sheets Other evaluation conditions The other evaluation conditions using the digital copying machine Konica 7075 are as follows. Was set to the condition.

Charging conditions Charging device: Scorotron charger, initial charging potential of -750
V exposure condition Set the exposure amount to make the exposed portion potential -50V.

Development conditions DC bias: -550V The developer is composed of a carrier having ferrite as a core and coated with an insulating resin, a styrene-acrylic resin as a main material, a colorant such as carbon black, a charge control agent and a low molecular weight polyolefin. Uses a toner developer in which silica, titanium oxide, etc. are externally added to the colored particles.

Transfer conditions Transfer pole; Corona charging system Cleaning conditions Hardness 70 °, impact resilience 34%, thickness 2 at cleaning part
(Mm), a cleaning blade having a free length of 9 mm was brought into contact with the counter by a weight load method so that the linear pressure was 20 (N / m).

The evaluation results are shown in Table 3.

[0118]

[Table 3]

As is clear from Table 3, the photoconductor 1 containing the charge transport material of the stereoisomer mixture in the charge transport layer, and the content ratio of the maximum isomer component of the mixture was within the range of the present invention,
In Nos. 2, 4, 5, and 6, image characteristics such as image density, fog, and resolution are good, and image characteristics such as black spots and white spots are less likely to occur, and all characteristics are improved in a balanced manner. In particular, the content of the maximum isomer component is 51 to 80% by mass.
The photoconductors 1, 4, and 5 have remarkable improvement effects. On the other hand, in the photoconductor 3 in which the maximum isomer component of the mixture is 37.5% by mass, which is outside the range of the present invention, the occurrence of white spots is increased and the resolution is also lowered. Further, in the photoconductors 7, 8 and 9 in which the maximum isomer component is 100% by mass, black spots and white spots often occur, and the image density and resolution are lowered.

Example 2 Synthesis Example 2 (Synthesis Example of Exemplified Compound T50)

[0121]

[Chemical 27]

10 g of the compound represented by the above formula was dissolved in 34 g of phosphorus oxychloride, heated to 50 ° C., and 23 ml of dimethylformamide was added dropwise little by little (heat generation of 40 to 40 ° C.).
70 ° C). The reaction solution was stirred for 15 hours while controlling the temperature to around 90 ° C. After cooling to 40 ° C, excess phosphorus oxychloride was sufficiently hydrolyzed and the precipitated crystals were separated by filtration, suspended in water and washed, and the washing was repeated until the washing liquid became neutral. 9.43 g (78%) of the represented bisformyl compound were obtained.

[0123]

[Chemical 28]

2 g of the bisformyl compound obtained above,
4.3 g of the phosphonate compound represented by the following structural formula was dissolved in 20 ml of dimethylformamide. 20 reaction liquids
While maintaining the temperature around 0 ° C, 1.0 g of sodium methoxide was added little by little (heat generation). After stirring for 4 hours, water 30
After adding ml, the product was purified by a conventional method to give yellow crystals 3.3.
g (81%) was obtained. When this yellow crystal was subjected to elemental analysis and mass spectrometry, the results shown in Table 4 below were obtained, and it was confirmed that the compound was T50.

[0125]

[Chemical 29]

Elemental analysis (C ₄₀ H ₃₉ N)

[0127]

[Table 4]

Mass spectrum (C ₄₀ H ₃₉ N) Mw (calculated value) = 533 Mw ⁺ (measured value) = 533 The compound of T50 obtained by the above synthesis is designated as T50-1. This T50-1 is the following liquid chromatography (HP
CL) measurement result cis-cis / cis-trans
/ Trans-trans mixing ratio is 1.2 / 2.0 /
It was 1.0. Incidentally, T50cis-cis, T50t
The structural formulas of trans-trans and T50cis-trans are shown below.

[0129]

[Chemical 30]

The T50-1 obtained above was analyzed by liquid chromatography for cis-cis form and cis-tran.
A compound separated into an s form and a trans-trans form was also obtained. T50c-c of these cis-cis bodies was changed to T50c-c,
T50 of the cis-trans form is converted to T50c-t, tra
The T50 of the ns-trans body is referred to as T50t-t. T
50-1 and T50c-c, T50c-t, T50t-t
4 of the above compounds and changing the mixing ratio, as shown in Table 5, cis-cis / cis-trans / trans-
Compounds of T50-2 to 50-6 having a mixing ratio of trans were prepared.

Preparation of Photoreceptors 10-18 The charge transport material (T20-1) used in Photoreceptor 1 was replaced with T50.
-1 to T50-6, T50c-c, T50c-t, T5
Photosensitive members 10 to 18 were prepared in the same manner as the photosensitive member 1 except that the isomer mixture ratio was changed as shown in Table 5 instead of 0t-t.

[0132]

[Table 5]

Example 1 using the photoconductors 10 to 18
The same evaluation as was done. The results are shown in Table 6.

[0134]

[Table 6]

As is clear from Table 6, the photoconductors 10 and 11 containing the charge transport material of the stereoisomer mixture in the charge transport layer and the maximum isomer component of the mixture being within the scope of the present invention,
In Nos. 13, 14, and 15, the image characteristics such as image density, fog, and resolution are good, and the occurrence of image defects such as black spots and white spots is small, and all the characteristics are improved in a balanced manner. In particular, the photoconductors 10, 13, and 14 in which the content of the maximum isomer component is 48 to 80 mass% have a remarkable improvement effect. On the other hand, in the photoconductor 12 in which the maximum isomer component of the mixture is 37.5% by mass, which is out of the range of the present invention, the occurrence of white spots is increased and the resolution is lowered. The maximum isomer component is 1
In the case of the photoconductors 16, 17 and 18 of 00 mass%, black spots and white spots are often generated, and the image density and resolution are lowered.

[0136]

As is apparent from the examples, by using the organic photoreceptor having the constitution of the present invention, an electrophotographic image having a good resolution without black spots or white spots can be obtained. Further, it is possible to provide an image forming method, an image forming apparatus and a process cartridge which can achieve a good electrophotographic image using the organic photoreceptor.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus as an example of an image forming method of the present invention.

[Explanation of symbols]

50 photoconductor drum (photoconductor) 51 Pre-charge exposure unit 52 Charger 53 Image exposure device 54 Developer 541 Development sleeve 543,544 developer stirring and conveying member 547 potential sensor 57 Paper Feed Roller 58 transfer electrode 59 Separation electrode (separator) 60 fixing device 61 Paper ejection roller 62 cleaning device 70 Process cartridge

Claims (14)

[Claims] 1. An organic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains a charge generating substance and a charge transporting substance, and at least one of the charge transporting substances is bis (arylethenylphenyl). ) An organophotoreceptor which is a stereoisomeric mixture of aniline compounds and in which the content of the maximum isomer component in the stereoisomeric mixture is 40 to 90% by mass. 2. An organic photoreceptor having a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer on a conductive support, wherein the charge transport layer is a stereoisomer of a bis (arylethenylphenyl) aniline compound. An organophotoreceptor which is a mixture and contains a charge-transporting substance in which the content of the maximum isomer component in the stereoisomer mixture is 40 to 90% by mass. 3. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1 or 2, wherein the aniline compound is a compound represented by the following general formula (1). [Chemical 1] [In the general formula (1), R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ represents a hydrogen atom or a substituted or unsubstituted aromatic group, and Ar ² represents a substituted or unsubstituted aromatic group. ] 4. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1, wherein the aniline compound is a compound represented by the following general formula (2). [Chemical 2] [In the general formula (2), R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ is a hydrogen atom or a substituted or unsubstituted aromatic group,
Ar ² represents a substituted or unsubstituted aromatic group. ] 5. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1 or 2, wherein the aniline-based compound is a compound represented by the following general formula (3). [Chemical 3] [In the general formula (3), R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ is a hydrogen atom or a substituted or unsubstituted aromatic group,
Ar ² represents a substituted or unsubstituted aromatic group. ] 6. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1 or 2, wherein the aniline compound is a compound represented by the following general formula (4). [Chemical 4] [In the general formula (4), R ¹ , R ² and R ³ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group.
Ar ¹ represents a hydrogen atom or a substituted or unsubstituted aromatic group, and Ar ² represents a substituted or unsubstituted aromatic group. ] 7. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1 or 2, wherein the aniline compound is a compound represented by the following general formula (5). [Chemical 5] [In the general formula (5), R ¹ , R ² and R ³ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group.
Ar ¹ represents a hydrogen atom or a substituted or unsubstituted aromatic group, and Ar ² represents a substituted or unsubstituted aromatic group. ] 8. The bis (arylethenylphenyl)
The organophotoreceptor according to claim 1 or 2, wherein the aniline compound is a compound represented by the following general formula (6). [Chemical 6] [In the general formula (6), R ¹ and R ² are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹
Represents a hydrogen atom or a substituted or unsubstituted aromatic group, and Ar ² represents a substituted or unsubstituted aromatic group. ] 9. The organophotoreceptor according to claim 3, wherein the substituted or unsubstituted aromatic group of Ar ¹ or Ar ² has the following general formula (7). . [Chemical 7] [In the general formula (7), R ^{6 to} R ¹⁷ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or 1 carbon atom.
To halogenated alkyl groups, halogen atoms or alkoxy groups having 1 to 4 carbon atoms. ] 10. The organic photoconductor has an intermediate layer between a conductive support and a photosensitive layer, wherein the organic photoconductor has an intermediate layer.
The organic photoreceptor according to any one of 1. 11. The intermediate layer contains N-type semiconductive fine particles and a binder resin.
The organic photoconductor according to item 1. 12. An image forming method, comprising forming an electrophotographic image using the organic photoconductor according to claim 1. Description: 13. An image forming apparatus, wherein an electrophotographic image is formed using the image forming method according to claim 12. 14. An organic photoconductor according to any one of claims 1 to 11 and at least one of a charging device, an image exposing device, a developing device, a transferring device, and a cleaning device, which are integrated with each other. A process cartridge characterized in that it can be taken in and out of a forming device.