JPH0611855A - Electrophotographic sensitive body, electrophotographic device and device unit having this electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the electrophotographic sensitive body which contains a charge transfer material having a novel structure and has a high sensitivity and a stable potential characteristic even at the time of repetitive use by incorporating a specific triphenyl amine compd. into a photosensitive layer. CONSTITUTION:The photosensitive layer contains the triphenyl amine compd. expressed by formula. In the formula, R1, R2 and R3 are the same or different and denote a hydrogen atom and 1 to 3C alkyl group, at least one of which denote an ethyl group and propyl group. The photosensitive layer is constituted of a layer contg. a charge generating material/a layer contg. a charge transfer material (lower layer/upper layer), etc. Since the compd. expressed by the formula has a high transfer capacity to holes, the compd. is usable as the charge transfer material in the photosensitive layer of this form. Further, a protective layer is provided on the surface of the photosensitive layer and an under coating layer is provided between the photosensitive layer and a conductive base for the purpose of improving durability and adhesiveness and controlling charge implantation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having a specific structure. The present invention also relates to an electrophotographic apparatus and an apparatus unit having the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer containing selenium, zinc oxide, cadmium, etc. as a main component has been widely used. These have some basic characteristics, but have problems such as difficulty in film formation, poor plasticity, and high manufacturing cost. Further, the inorganic photoconductive material is generally highly toxic, and there are great restrictions in manufacturing and handling.

On the other hand, organic photoconductors containing an organic photoconductive compound as a main component have been attracting attention in recent years because they have many advantages such as supplementing the above-mentioned drawbacks of inorganic photoconductors. Has been proposed, and some of them have been put into practical use.

As such an organic photoreceptor, poly-N is used.
An electrophotographic photoreceptor containing a charge transfer complex formed of a photoconductive polymer represented by vinylcarbazole and a Lewis acid such as 2,4,7-trinitro-9-fluorenone as a main component has been proposed. There is. These organic photoconductive polymers are superior to the inorganic photoconductive polymers in terms of lightness, film forming property, etc., but they are inorganic photoconductive in terms of sensitivity, durability and stability against environmental changes. It is inferior to the material and not always satisfactory.

After that, a function-separated type electrophotographic photosensitive member in which a charge generating function and a charge transporting function are shared by different substances brings about a remarkable improvement in sensitivity and durability, which have been the drawbacks of conventional organic photosensitive members. It was Such a function-separated type photoconductor has the advantage that the material selection range of each of the charge generating substance and the charge transporting substance is wide, and that an electrophotographic photoconductor having arbitrary characteristics can be prepared relatively easily.

As the charge generating substance, various azo pigments,
Polycyclic quinone pigments, cyanine dyes, squaric acid dyes and pyrylium salt dyes are known. Among them, many structures have been proposed for azo pigments in terms of strong light resistance, large charge generation capability, easy material synthesis, and the like.

On the other hand, as the charge-transporting substance, for example, a pyrazoline compound described in JP-B-52-4188; JP-B-55.
-42380 and JP-A-55-52063; hydrazone compounds; JP-B-58-32372 and JP-A-61-132955, triphenylamine compounds; and JP-A-54-151955 and The stilbene compounds and the like disclosed in JP-A-58-198043 are known.

The properties required for these charge transport materials are (1) stability against light and heat, (2)
Stable with respect to ozone, NO _x, nitric acid, etc. generated by corona discharge, (3) having high charge transport ability, (4) having high compatibility with organic solvents and binders, and ( 5) It is easy to manufacture and inexpensive.

With the recent demand for higher image quality and higher durability, charge transport materials that can satisfy the above conditions at a higher level have been studied.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member having a photosensitive layer containing a charge transporting substance having a novel structure.

Another object of the present invention is to have high sensitivity,
An object of the present invention is to provide an electrophotographic photosensitive member having stable potential characteristics even after repeated use.

A further object of the present invention is to provide an electrophotographic apparatus and apparatus unit having the above electrophotographic photosensitive member.

[0013]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following formula (1).

[0014]

[Outside 2] (In the formula, R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, at least one of which represents an ethyl group or a propyl group.) An electrophotographic photosensitive member characterized by containing a compound.

The present invention is also an electrophotographic apparatus and apparatus unit having the above electrophotographic photosensitive member.

Preferred examples of the compound represented by the formula (1) will be given below. Of course, the present invention is not limited to these compounds.

[0017]

[Outside 3]

[0018]

[Outside 4]

[0019]

[Outside 5]

Next, synthetic examples used in the present invention will be shown.

Synthesis Example 1 (Synthesis of Exemplified Compound No. 1) In a 200 ml three-necked flask, 13.5 g of 4-propylaniline, 50 g of 4-iodotoluene, 10.0 g of anhydrous potassium carbonate and copper powder 5.
0 g was added and the mixture was heated with stirring at 190 to 200 ° C. for 8 hours. After cooling, the mixture was filtered, concentrated under reduced pressure, MEK was added, and crude crystals were collected by filtration.

The obtained crude crystals were purified by column to obtain 22.5 g of p-ditoluyl-4-propylaniline (yield 81%) Synthesis Example 2 (Synthesis of Exemplified Compound No. 13) 4 in a 200 ml three-necked flask. -Ethylaniline 12.1 g, 4-iodotoluene 50 g, anhydrous potassium carbonate 10.0 g, copper powder 5.0
g was added and the mixture was heated and stirred at 190 to 200 ° C. for 8 hours. After cooling, the mixture was filtered, concentrated under reduced pressure, MEK was added, and crude crystals were collected by filtration.

The obtained crude crystals were purified by column to obtain 25.6 g of p-ditoluyl-4-ethylaniline (yield 8
5%).

Examples of the constitution of the photosensitive layer of the electrophotographic photosensitive member of the present invention include the following modes.

(1) Layer containing charge generating substance / layer containing charge transporting substance (lower layer / upper layer) (2) Layer containing charge transporting substance / layer containing charge generating substance (lower layer / upper layer) ( 3) Layer Containing Charge Generating Substance and Charge Transporting Substance Since the compound represented by the formula (1) of the present invention has a high ability to transport holes, it can be used as the charge transporting substance in the photosensitive layer of the above-mentioned form. it can. When the form of the photosensitive layer is (1), the polarity of primary charging is preferably negative, when it is (2) it is positive, and when it is (3), it may be either positive or negative.

Further, in the electrophotographic photoreceptor of the present invention, a protective layer is provided on the surface of the photosensitive layer or a layer between the photosensitive layer and the conductive support is provided in order to improve durability and adhesiveness or control charge injection. An undercoat layer may be provided. The structure of the photoconductor of the present invention is not limited to the above basic structure.

In the present invention, the form (1) is preferable among the above-mentioned constitutions, which will be described in more detail below.

Examples of the conductive support in the present invention include the following.

(1) Aluminum, aluminum alloys,
A plate-shaped or drum-shaped metal or alloy such as stainless steel or copper.

(2) A metal or alloy such as aluminum, aluminum alloy, palladium, rhodium, gold and platinum is vapor-deposited on the non-conductive support such as glass, resin and paper or the conductive support described in (1) above. A thin film formed by laminating.

(3) A layer containing a conductive polymer, a conductive compound such as tin oxide and indium oxide on the non-conductive support such as glass, resin and paper or on the conductive support of the above (1). Formed by vapor deposition or coating.

Examples of the charge generating substance that can be used in the present invention include the following substances. These charge generating substances may be used alone or in combination of two or more.

(1) Azo pigments such as monoazo, bisazo and trisazo (2) Phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine (3) Indigo pigments such as indigo and thioindigo (4) Perylene anhydride and perylene Perylene pigments such as acid imides (5) Polycyclic quinone pigments such as anthraquinone and pyrenequinone (6) Squarylium dye (7) Pyrylium salts and thiopyrylium salts (8) Triphenylmethane dyes (9) Selenium and amorphous Inorganic substance such as silicon A layer containing a charge generating substance, that is, a charge generating layer is formed by dispersing the above charge generating substance in an appropriate binder and coating it on a conductive support. be able to. Also, vapor deposition, sputtering or C on a conductive support.
It can also be formed by forming a thin film by a dry method such as VD.

The binder can be selected from a wide range of binder resins, for example, polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin. , Vinyl acetate resin, phenol resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin, alkyd resin, epoxy resin, urea resin and vinyl chloride-vinyl acetate copolymer resin, but are not limited thereto. Not something. These may be used alone or as a mixture or as a copolymer polymer of one kind or two or more kinds.

The proportion of the resin in the charge generation layer is preferably 80% by weight or less, more preferably 40% by weight or less, based on the total weight of the layer. Further, the film thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.
It is preferably from 01 μm to 2 μm.

Various sensitizers may be added to the charge generation layer.

The layer containing the charge-transporting substance, that is, the charge-transporting layer can be formed by combining at least the triphenylamine compound represented by the above formula (1) and a suitable binder resin. Examples of the binder resin used in the charge transport layer include photoconductive polymers such as polyvinylcarbazole and polyvinylanthracene, in addition to those used in the charge generation layer.

The compounding ratio of the binder resin and the triphenylamine compound of the present invention is preferably 10 to 500 parts by weight of the triphenylamine compound per 100 parts by weight of the binder resin.

The charge transport layer is electrically connected to the above-mentioned charge generation layer and has a function of receiving charge carriers generated in the charge generation layer in the presence of an electric field and transporting the charge carriers to the surface of the photoreceptor. have. Since this charge transport layer has a limit to transport charge carriers, the film thickness cannot be increased more than necessary, but 5 μm to 4 μm.
It is preferably 0 μm, particularly 10 μm to 30 μm
It is preferably m.

Further, an antioxidant, an ultraviolet absorber, a plasticizer or a known charge transporting substance can be added to the charge transporting layer as required.

As a coating method for forming the above-mentioned various layers by coating, an appropriate organic solvent is used, and a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Mayer bar coating method, a blade coating method. And the like.

The electrophotographic photoreceptor of the present invention can be used not only in an electrophotographic copying machine, but also in a laser beam printer,
It can be widely used in electrophotographic application fields such as CRT printers, LED printers, facsimiles and electrophotographic plate making systems.

FIG. 1 shows a schematic structure of an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. The photosensitive member 1 receives uniform charging of a positive or negative predetermined potential on the peripheral surface of the photosensitive member 1 by the charging unit 2 during its rotation process, and then an optical image exposure L (slit exposure) by an image exposing unit (not shown) in the exposure unit 3.・ Receiving laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photoconductor.

The formed electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is generated when the photosensitive body 1 rotates between the photosensitive body 1 and the transfer means 5 from a paper feeding portion (not shown). The transfer material 5 is sequentially transferred to the transfer material P which is synchronized and fed.

The transfer material P, which has received the image transfer, is separated from the surface of the photoconductor and is introduced into the image fixing means 8. The image is fixed by the transfer material P and is printed out as a copy.

After the image transfer, the surface of the photoconductor 1 is cleaned by the cleaning means 6 to remove the transfer residual toner, and is further discharged by the pre-exposure means 7 to be repeatedly used for image formation. .

As the uniform charging means 2 for the photoconductor 1, a corona charging device is generally widely used. In addition, the transfer device 5
Corona transfer means are also widely used. In the present invention, among the above-described components such as the photoconductor, the developing unit, and the cleaning unit, a plurality of components are integrally combined and configured as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. May be. For example, at least one of the charging means, the developing means and the cleaning means may be integrally supported together with the photoconductor to form a unit, and a single unit detachably attached to the apparatus main body by using guide means such as rails of the apparatus main body. good.

When the electrophotographic apparatus is used as a copying machine or a printer, the light image exposure L irradiates the photoconductor with reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal. According to this signal, the laser beam is scanned, the LED array is driven, or the liquid crystal shutter array is driven to irradiate the photoconductor with light.

When used as a printer for a facsimile, the optical image exposure L becomes an exposure for printing received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The entire controller 11 is CP
It is controlled by U17. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 13. The data received from the partner station is sent to the printer 19 through the receiving circuit 12. Predetermined image data is stored in the image memory. The printer controller 18 is the printer 1
9 is controlled. 14 is a telephone.

The image received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, and then the CPU 17 decodes the image information to sequentially decode the image memory 16. Stored in. And
When the image of at least one page is stored in the memory 16, the image of that page is recorded. The CPU 17 reads the image information of one page from the memory 16 and sends the decoded image information of one page to the printer controller 18. Upon receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page.

The CPU 17 is receiving the next page while the printer 19 is recording.

The image is received and recorded as described above.

The present invention will be described below with reference to examples.

[0056]

【Example】

Example 1 A sand pigment was used together with 1.0 g of an azo pigment represented by the following formula and 0.5 g of butyral resin (degree of butyralization: 80 mol%) dissolved in 60 ml of tetrahydrofuran in a sand mill.
Dispersion was carried out for 8 hours to obtain a charge generation layer coating liquid.

[0057]

[Outside 6]

This coating solution was applied onto an aluminum sheet with a Meyer bar so that the film thickness after drying was 0.2 μm, and dried to form a charge generation layer.

Next, the exemplified compound N is used as a charge transport material.
o. 1. 1.0 g of polycarbonate resin (weight average molecular weight 20,000) 1.0 g of monochlorobenzene 7.
It was dissolved in 0 g. This solution was applied onto the above charge generation layer with a Meyer bar and dried to give a dry film thickness of 23.
A μm charge transport layer was formed.

The obtained electrophotographic photosensitive member was manufactured by Kawaguchi Electric Co., Ltd.
Using an electrostatic copying paper tester Model-SP-428, a static method was used for corona charging at -5 KV and holding for 1 second in a dark place, followed by exposure at an illuminance of 20 lux to examine charging characteristics.

The charging characteristics include the surface potential (V ₀ ) immediately after charging and the surface potential (V ₁ ) after being attenuated for 1 second and V
_The exposure dose (E _1/5 ) required to attenuate ₁ to 1/5, that is, the sensitivity was measured.

Further, in order to evaluate the fluctuation of the light potential and the dark potential when repeatedly used, the photoconductor prepared in this example was manufactured by Canon Inc. PPC copier NP-382.
Attach it to the photosensitive drum cylinder of 5, and
0 copies were made, and the light potential (V _L ) and the dark potential (V _D ) at the initial stage and after 5,000 copies were measured. The initial V _D and V _L were set to about -700V and -200V, respectively. The results are shown in Table 1 below.

[0063]

[Table 1]

Examples 2 to 20 Exemplified compound No. used as the charge transport material in Example 1
Exemplified Compound No. 1 instead of 1. 2, 3, 4, 5, 7,
9, 10, 11, 12, 13, 14, 15, 16, 1
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that 8, 19, 20, 22, 23 and 24 were used. The results are shown in Table 2.

[0065]

[Table 2]

Comparative Examples 1 to 4 Exemplified Compound N Used as a Charge Transport Material in Example 1
o. Instead of 1, the following comparative compound No. An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that 1 to 4 were used.
evaluated. The results are shown in Table 3.

[0067]

[Outside 7]

[0068]

[Table 3]

As is clear from Table 1, Table 2 and Table 3, the electrophotographic photosensitive member of the present invention is extremely excellent in sensitivity and potential stability during repeated use as compared with the electrophotographic photosensitive member using the comparative compound. You can see that

Example 21 1.0 g of oxytitanium phthalocyanine was added to a solution prepared by dissolving 0.4 g of a phenoxy resin in 100 g of cyclohexanone, and dispersed by a ball mill for 40 hours. After coating this dispersion on an aluminum sheet with a Meyer bar, 80
The charge generation layer having a thickness of 0.15 μm was formed by drying at a temperature of 0.5 hours.

Exemplified compound No. 1 1.0 g and 1.0 g of bisphenol Z type polycarbonate resin (weight average molecular weight 20,000) were added to 7.0 g of monochlorobenzene.
Dissolved in. This solution was applied onto the charge generation layer previously formed with a Meyer bar and then dried at 120 ° C. for 1.0 hour to form a charge transport layer having a film thickness of 21 μm.

The obtained electrophotographic photosensitive member was subjected to corona discharge of -5 KV. The surface potential (V ₀₎ Toko surface potential after leaving the photoreceptor at one second dark (V ₁₎ at this time was measured. The sensitivity was evaluated by measuring the exposure dose (E _1/6 ) required to attenuate V ₁ to ⅙. At this time, a ternary semiconductor laser of gallium / aluminum / arsenic was used as a light source (output: 5 mW, oscillation wavelength: 780 n
m) was used. The results are shown below.

V ₀ : -710 (V) V ₁ : -705 (V) E _1/6 : 0.25 (μJ / cm ² ).

Next, an actual image forming test was carried out by attaching the above-mentioned photosensitive member to a laser beam printer (LBP-CX manufactured by Canon Inc.) which is an electrophotographic printer of a reversal development system equipped with the same semiconductor laser as that described above. It was The conditions are as follows. Surface potential after primary charging:
-700 V, surface potential after image exposure: -150 V, transfer potential +700 V, development polarity: negative polarity, process speed:
50 mm / sec, development condition (development bias): -45
0V, scan method after image exposure: image scan, exposure before primary charging: 22.0 lux · sec full red exposure.

When images were continuously output on 3,000 sheets under these conditions, excellent images could be stably obtained from the initial stage to 3,000 sheets.

Example 22 Exemplified Compound No. as a charge transport material. Exemplified Compound No. 1 instead of 1. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 21 except that 13 was used. The charging characteristics are excellent as described below, and the obtained image is 3,0 from the beginning.
It was stable and excellent up to 00 sheets.

V ₀ : −720 (V) V ₁ : −715 (V) E _1/6 : 0.25 (μJ / cm ² ).

Example 23 An alcohol-soluble nylon (6
A 2-% methanol solution of -66-610-12 quaternary nylon copolymer) was applied and a subbing layer having a film thickness after drying of 0.5 μm was formed.

Next, a solution prepared by adding 0.5 g of the azo pigment represented by the following formula to 10 ml of tetrahydrofuran was dispersed with a sand mill.

[0080]

[Outside 8]

Then, the exemplified compound No. 110 g of bisphenol A type polycarbonate resin (weight average molecular weight of 30,000) and monochlorobenzene (80
Parts by weight) -dichloromethane (20 parts by weight) dissolved in 70 g of the solution, added to the dispersion liquid prepared above, and further added with a sand mill for 2 more.
Time dispersed.

This dispersion was applied onto the previously prepared undercoat layer with a Meyer bar so that the film thickness after drying was 18 μm, and dried.

The electrophotographic characteristics of the obtained electrophotographic photosensitive member were evaluated in the same manner as in Example 11. The results are shown below.

V ₀ : -710 (V) V ₁ : -700 (V) E _1/6 : 0.67 (μJ / cm ² ).

Example 24 Exemplified Compound No. as a charge transport material. Exemplified Compound No. 1 instead of 1. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 2 except that 13 was used. The results are shown below.

V ₀ : -700 (V) V ₁ : -690 (V) E _1/6 : 0.64 (μJ / cm ² )

[0087]

As described above, the electrophotographic photosensitive member having the photosensitive layer containing the triphenylamine compound of the present invention has high sensitivity, and in the continuous image formation, fluctuations in the light potential and the dark potential. Is small and has excellent durability.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram showing an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of the present invention 1a Axis 2 Charging means 3 Exposure section 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means 10 Image reading section 11 Controller 12 Reception circuit 13 Transmission circuit 14 Telephone 15 Line 16 Image memory 17 CPU 18 Printer controller 19 Printer L Optical image exposure P Transfer material

Front page continued (72) Inventor Norihiro Kikuchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following formula (1): (In the formula, R ₁ , R ₂ and R ₃ are the same or different and each represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, at least one of which represents an ethyl group or a propyl group.) An electrophotographic photoreceptor containing a compound. 2. The electrophotographic photosensitive member according to claim _1, wherein at least one of R _{1 to} R ₃ is an ethyl group. _3. The electrophotographic photosensitive member according to claim _1, wherein at least one of R _{1 to} R ₃ is a propyl group. 4. The electrophotographic photoreceptor according to claim 1, means for forming an electrostatic latent image, means for developing the formed electrostatic latent image, and means for transferring the developed image to a transfer material. An electrophotographic device characterized by. 5. The electrophotographic photosensitive member according to claim 1, and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit are integrally supported,
The device unit is detachable from the device body.