JPH09319128A - Electrophotographic photoreceptor - Google Patents

Abstract

(57) Abstract: A function-separated type electrophotographic photosensitive member having an undercoat layer has high sensitivity, small residual potential, and excellent durability with little fluctuation in these characteristics even after repeated use. An electrophotographic photoreceptor is provided. It is also highly sensitive,
A function-separated electrophotographic photosensitive member that has a small residual potential, has little variation in these characteristics even after repeated use, has excellent electrophotographic characteristics, has good mechanical durability, and has excellent productivity. provide. An electrophotographic photosensitive member is obtained by sequentially stacking a charge generation layer and a charge transport layer containing a hole transport substance on a conductive substrate, and a fluorene compound is provided between the conductive substrate and the charge generation layer. An undercoat layer to be contained is provided. Further, in an electrophotographic photoreceptor having a charge generation layer and a charge transport layer laminated on a conductive substrate, the charge generation layer contains at least a charge generation substance, a hole transport substance, an electron transport substance and a binder resin, A fluorene compound is used as the electron transport material.

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 suitable for use in a copying machine, a printer or the like using an electrophotographic process.

[0002]

2. Description of the Related Art In the electrophotographic process, the surface of an electrophotographic photosensitive member is uniformly charged, and the charged surface of the photosensitive member is subjected to image exposure to form an image-like electrostatic latent image on the surface of the photosensitive member. The basic principle is to visualize an electrostatic latent image by developing it with a developer such as toner. Therefore, the electrophotographic photosensitive member used in this process must have good chargeability and rapid surface potential decay by light irradiation.
In order to satisfy these characteristics, it is necessary to use a substance that has a high solid-state physical property such as dark resistance, good quantum efficiency for generating charge carriers, and high charge mobility.

Conventionally, electrophotographic photoreceptors using inorganic compounds such as selenium, selenium-tellurium alloys, and arsenic selenium have been adopted as those satisfying these physical property values, and have been used in many copying machines. However, since these materials have environmental problems such as toxicity and are used in an amorphous state, they are difficult to handle because, for example, they are easily crystallized due to heat, dirt, etc. and their characteristics are deteriorated. Also, Equation 1
Since it is necessary to perform vacuum evaporation to a film thickness of 0 μm, there are drawbacks such as high cost.

In order to improve these drawbacks, electrophotographic photoreceptors using organic materials have been actively developed, and some of them have been put to practical use. Most of the organic electrophotographic photoreceptors that have been put to practical use have a photosensitive layer composed of a layer having a charge generating function (charge generating layer) and a layer having a charge transporting function (charge transporting layer) on a conductive substrate. This is a function-separated type electrophotographic photosensitive member. By separating the functions, the selection range of materials is expanded, and the characteristics such as sensitivity, repeatability and mechanical strength are improved, and it is installed in many copiers, printers, etc. It has started to be done.

However, in such an organic electrophotographic photosensitive member, when the photosensitive layer is directly provided on the conductive substrate, defects of the conductive substrate, that is, surface defects such as scratches, impurities and corrosive substances are directly reflected in the image. It often causes abnormal images such as black spots and white spots. In particular, the charge generation layer in a function-separated type electrophotographic photosensitive member is usually required to be a thin film having a thickness of several μm or less, and if there is a defect on the surface of the conductive substrate, a coating defect is likely to occur on the charge generation layer, and the conductive substrate In many cases, the adhesion between the photosensitive layer and the photosensitive layer is poor, and the entire photosensitive layer may be peeled off due to a scratch on the small photosensitive layer, which lowers the productivity of the electrophotographic photosensitive member.

In order to prevent these problems, many organic electrophotographic photoreceptors are provided with an undercoat layer such as a barrier layer or an adhesive layer between the conductive substrate and the photosensitive layer. The subbing layer is mainly composed of a thin film of insulating polymer material with a submicron thickness, but because it is insulating, it causes a decrease in sensitivity, an increase in residual potential, etc., and it is used repeatedly. However, there is a drawback that these characteristics greatly vary and durability is poor.

Therefore, various methods have been proposed in order to eliminate these drawbacks, and an inorganic conductive filler is contained in the undercoat layer.
And the like, a method of incorporating an ion-conductive polymer into the undercoat layer, a method of incorporating an electron transporting substance having an acceptor property into the undercoat layer, and the like.

For example, Japanese Patent Publication No. 63-19869 discloses the use of titanium oxide, tin oxide or the like as an inorganic conductive filler, but these need to be uniformly dispersed in the undercoat layer coating solution. However, there are technical difficulties in preparing the dispersion and pot life. JP-A-52-
No. 25638 and Japanese Patent Laid-Open No. 58-30757 disclose ion conductive polymers such as soluble nylon,
Although the use of polyamide or the like is disclosed, the above drawbacks have not been solved because of its low conductivity. Further, as the acceptor electron-transporting substance contained in the undercoat layer, an acceptor compound such as trinitrofluorenone or tetracyanoquinodimethane is used.
These have a problem in safety, and the stability of the compound, the compatibility with the insulating polymer material, etc. are poor, and the organic electrophotographic photoreceptor having such an undercoat layer has a problem such as an increase in residual potential. is there. As described above, in the case where the undercoat layer is provided, the drawbacks such as a decrease in sensitivity, an increase in residual potential, and a deterioration in durability in repeated use have not yet been sufficiently solved.

Further, in the function-separated type electrophotographic photoreceptor, the charge-generating substance also has a charge-transporting function in the charge-generating layer, but both holes and electrons can be efficiently moved. Since there are few charge generation substances, it is necessary to shorten the moving distance, and the charge generation layer is made thin. Further, in order to improve the sensitivity of the electrophotographic photosensitive member, it is necessary for the charge generation layer to absorb light efficiently, and a large amount of the charge generation substance is contained in the charge generation layer.

The charge generation layer is generally formed with a charge generation substance dispersed in a binder resin.
It is quite difficult to stably maintain a dispersion liquid in which a large amount of charge generation material is uniformly dispersed in a binder resin, and it is quite difficult to form a thin film by the dispersion liquid. It has a decisive influence on the yield of electrophotographic photoreceptor production, and in order to form a thin film, the conductive substrate surface must have a fairly high level of smoothness, which results in the production of electrophotographic photoreceptors. And the manufacturing cost is increasing. Further, the charge generation layer thin film containing a large amount of the charge generation substance has a weak film strength, and the function-separated electrophotographic photoreceptor having such a charge generation layer has a drawback that mechanical durability is poor.

On the other hand, if the charge generation layer is thickened to form a charge generation layer having no coating defects in order to improve the productivity of the electrophotographic photosensitive member, both holes and electrons are efficiently generated in the charge generation layer. However, there is a problem that the sensitivity is low, the residual potential is particularly large, and further, these characteristics fluctuate and the durability is deteriorated during repeated use of the electrophotographic photosensitive member. If the amount of the charge generating substance in the charge generating layer is reduced in order to improve the mechanical durability of, there is a problem that the sensitivity is lowered.

Conventionally, it has a high sensitivity, a small residual potential, a small change in these characteristics even after repeated use, an excellent durability of electrophotographic characteristics, a good mechanical durability, and a high productivity. It has been difficult to obtain a function-separated type electrophotographic photosensitive member excellent in performance.

[0013]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to solve the above problems and to provide a function-separated electrophotographic photosensitive member having an undercoat layer with high sensitivity and small residual potential. An object of the present invention is to provide an electrophotographic photosensitive member having excellent durability with little variation in these characteristics even after repeated use.

Further, the object of the present invention is high sensitivity, small residual potential, little change in these characteristics even after repeated use, excellent electrophotographic characteristic durability, and good mechanical durability. Another object of the present invention is to provide a function-separated electrophotographic photosensitive member that is excellent in productivity.

[0015]

The above object of the present invention is to provide an electrophotographic photosensitive member comprising a conductive substrate, and a charge generation layer and a charge transport layer containing a hole transport substance, which are sequentially laminated on the conductive substrate. This is achieved by an electrophotographic photosensitive member characterized in that an undercoat layer containing a fluorene compound is provided between the substrate and the charge generation layer.

Another object of the present invention is to provide an electrophotographic photosensitive member comprising a conductive substrate and a charge generating layer and a charge transporting layer laminated on the conductive substrate.
This is achieved by an electrophotographic photoreceptor containing a hole transporting material, an electron transporting material and a binder resin, wherein the electron transporting material is a fluorene compound. As the fluorene compound used in the present invention, a compound represented by the following general formula (1) is particularly preferable.

[0017]

[Chemical 1]

(In the formula, R ₁ and R ₂ represent a fluoroalkoxycarbonyl group, and m and n represent an integer of 0 to 4. Z
Represents an oxygen atom, = C (X) (Y) or = N (W),
X and Y are a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted Represents a heterocyclic group, W represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. )

The fluorene compound represented by the general formula (1) has an electron transporting ability. In particular, the fluorene compound is contained in the undercoat layer, or the fluorene compound is contained in a charge generating substance, a hole transporting substance and By including it in the charge generation layer together with the binder resin, it is possible to obtain an electrophotographic photoreceptor having high sensitivity, a small residual potential, a small variation in these characteristics even after repeated use, and an excellent durability. In addition to this, it is possible to obtain a function-separated type electrophotographic photosensitive member which is good and excellent in productivity.

The fluoroalkoxycarbonyl group in the above general formula (1) may be an alkoxycarbonyl group having a fluorine-substituted alkyl group, and the fluorine-substituted alkyl group may be --CH ₂ CF ₃ or-(CH ₂ ) ₂ C
_{F 3, - (CH 2)} 3 CF 3, - (CH 2) 4 CF 3, -CH 2 CH
_{2 F, - (CH 2)} 3 CH 2 F, -CH 2 CHF 2, - (CF 2) 2
_{CF 3, -CH 2 CF 2 CHFCF} 3, -CH (CF 3) 2, -
_{(CH 2) 2 CF 2 CF} 3, -CH 2 (CF 2) 2 CF 3, -CH
Fluoroalkyl groups such as ₂ (CF ₂ ) ₇ CF ₃ can be mentioned.

As the substituted or unsubstituted alkyl group,
Examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group and the like, and a trifluoromethyl group and a trichloromethyl group in which these are substituted with a halogen atom such as a fluorine atom and a chlorine atom.

Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the substituent in the aryl group include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, a chlorine atom, a bromine atom and a fluorine atom. And halogen-substituted alkyl groups such as trifluoromethyl group and trichloromethyl group, and cyano groups.

The alkoxycarbonyl group includes methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group, n-butyloxy group, iso-butyloxy group, n-hexyloxy group, n-octyloxy group, n.
-Examples thereof include an alkoxycarbonyl group having an alkoxyl group such as a decyloxy group, and examples of the substituent in the alkoxycarbonyl group include a chlorine atom, a bromine atom, a halogen atom such as a fluorine atom, a trifluoromethyl group and a trichloromethyl group. Examples thereof include halogen-substituted alkyl groups.

Examples of the aryloxycarbonyl group include an aryloxycarbonyl group having an aryl group such as a phenyl group and a naphthyl group, and a substituent in the aryloxycarbonyl group is a methyl group, an ethyl group, a propyl group, Examples thereof include an alkyl group such as a butyl group, a halogen atom such as a chlorine atom, a bromine atom and a fluorine atom, a halogen-substituted alkyl group such as a trifluoromethyl group and a trichloromethyl group, and a cyano group.

As the heterocyclic group, a thiazole ring,
Examples of the heterocyclic group include an oxazole ring, a benzothiazole ring, and a benzoxazole ring. Substituents on the heterocyclic ring include a methyl group, an ethyl group, a propyl group, an alkyl group such as a butyl group, a methoxy group, and an ethoxy group. , An alkoxycarbonyl group containing an alkoxyl group such as a propoxy group and a butoxy group, a chlorine atom, a bromine atom,
Halogen atom such as fluorine atom, amino group substituted with alkyl group such as methyl group and ethyl group, cyano group,
A nitro group etc. can be illustrated. Representative examples of the fluorene compound include those shown in Table 1-1 to Table 1-10, but are not limited thereto.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

[0032]

[Table 7]

[0033]

[Table 8]

[0034]

[Table 9]

[0035]

[Table 10]

In an electrophotographic photosensitive member comprising a conductive substrate, a charge generating layer, and a charge transporting layer containing a donor compound having a hole transporting ability, which are sequentially stacked, between the conductive substrate and the charge generating layer. In order to produce an electrophotographic photoreceptor of the present invention in which an undercoat layer containing a fluorene compound is provided, a solution containing a binder resin and a fluorene compound is applied onto a conductive substrate and dried to form an undercoat layer. Then, a charge generation layer and a charge transport layer may be sequentially laminated on the undercoat layer by a known method.

The binder resin used for the undercoat layer is not particularly limited, and examples thereof include polyethylene resin, polypropylene resin, acrylic resin, polystyrene resin, vinyl chloride resin, vinyl acetate resin, polycarbonate resin,
Addition polymerization type resin such as polyarylate resin, phenoxy resin, polyurethane resin, butyral resin, polyamide resin, vinylidene fluoride resin, silicone resin, fibrin resin, cyanoethyl pullulan, phenol resin, melamine resin, alkyd resin, epoxy resin, Polyaddition type resin,
Examples thereof include polycondensation type resins and copolymer resins containing two or more of these repeating units.
It is possible to use a mixture of two or more kinds.

Since the fluorene compound represented by the general formula (1) is soluble in many solvents, the solvent can be appropriately selected and used in consideration of the binder resin. Examples of the solvent include aromatic solvents such as benzene, toluene, xylene, and chlorobenzene, dichloromethane, 1,
Halogen-based solvents such as 2-dichloroethane and chloroform, ester-based solvents such as methyl acetate, ethyl acetate, propyl acetate and ethyl formate, ketone-based solvents such as acetone, methyl ethyl ketone and cyclohexanone, ether-based solvents such as diethyl ether, dioxane and tetrahydrofuran. , Alcohol solvents such as methanol, ethanol and isopropanol, and dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like.

The content of the fluorene compound is preferably 1 to 50% by weight, more preferably 2 to 30% by weight, based on the binder resin. If it is less than 1% by weight, the effect is not exhibited, and if it exceeds 50% by weight, the charging property becomes poor. The thickness of the undercoat layer is 0.1-2.
0 μm is preferred.

As the conductive substrate used in the present invention,
Metal plates such as aluminum, nickel, copper, stainless steel,
Examples thereof include a metal drum or a metal foil, a plastic film coated with a thin film of aluminum, tin oxide, copper iodide, or the like, or glass.

To form the charge generating layer on the undercoat layer, a dispersion liquid in which the charge generating substance is dispersed in a binder resin is applied on the undercoat layer and dried, or the charge generating substance is applied on the undercoat layer. It may be vapor-deposited on top. As the charge generating substance, bisazo dye, trisazo dye, phthalocyanine dye, quinacridone dye, perylene dye, polycyclic quinone dye, indigo dye, cyanine dye, pyrylium dye, bisbenzimidazole dye, indanthrone dye, triarylmethane dye, Organic dyes such as thiazine dyes, oxozine dyes, squarylium dyes, anthraquinone dyes, xanthene dyes, selenium, selenium alloys, cadmium sulfide, cadmium sulphide selenide, and inorganic compounds such as amorphous silicon are included, and when they are always present with a binder resin. Is preferably used in an amount of 10 to 400 parts by weight, and particularly preferably 25 to 100 parts by weight with respect to 100 parts by weight of the charge generating substance. The thickness of the charge generation layer is 0.05 to 1
0 μm is preferable, and 0.1 to 2 μm is particularly preferable.

Further, in order to form the charge transport layer on the charge generation layer, a solution containing a hole transport substance and a binder resin may be applied onto the charge generation layer and dried. Examples of the hole transport material include compounds having a triphenylamine moiety in the molecule, hydrazone compounds, pyrazoline compounds,
Triphenylmethane compound, oxazole compound, oxadiazole compound, carbazole group-containing compound, styryl compound, butadiene compound, polysilane compound,
Donor compounds such as poly-N-vinylcarbazole and pyrene-formalin condensates can be used alone or in combination of several kinds. The content of the hole-transporting substance in the charge-transporting layer is preferably 25 to 400 parts by weight, more preferably 50 to 400 parts by weight, based on 100 parts by weight of the binder resin.
200 parts by weight are preferred. Further, the thickness of the charge transport layer is 5
-60 μm is preferable, and 10-30 μm is particularly preferable.

If necessary, additives can be added to the charge transport layer. Examples of such additives include antifoaming agents, antioxidants, adhesion aids, plasticizers and the like.

As the binder resin in the charge generation layer or the charge transport layer, those exemplified as the binder resin used in the undercoat layer can be used.

The undercoat layer, the charge generation layer or the charge transport layer can be coated by a known coating method, for example, a dipping coater, a calendar coater, a kiss coater, a gravure coater, a blade coater, a spray coater or a spin coater.

Next, in the electrophotographic photosensitive member having a charge generating layer and a charge transporting layer laminated on a conductive substrate, the charge generating layer is at least a charge generating substance, a hole transporting substance, an electron transporting substance and a binder resin. The electrophotographic photoreceptor of the present invention is characterized in that the electron transport material is a fluorene compound.

This electrophotographic photosensitive member contains a hole transporting substance capable of moving holes in the charge generating layer and a fluorene compound as an electron transporting substance capable of moving electrons, and therefore, it is The holes and electrons generated in the charge generation substance by irradiation do not remain in the charge generation layer, but can move rapidly in the opposite directions according to the charging polarity, and have high sensitivity, small residual potential, and repeated It exhibits excellent characteristics that there is little variation in these characteristics during use.

Further, since holes and electrons can rapidly move in the charge generation layer in opposite directions depending on the charge polarity, the charge generation layer can be made relatively thick and the conductive substrate can be formed. It is easy to form a defect-free charge generation layer on the top, and the electroconductive substrate surface does not require the same level of smoothness as the electroconductive substrate surface in the conventional function-separated electrophotographic photoreceptor. The productivity of the body is increased and the manufacturing cost can be reduced.

Further, in this electrophotographic photosensitive member,
The content of the charge generating substance in the charge generating layer can be reduced as compared with the content in the charge generating layer of the conventional function-separated electrophotographic photosensitive member without lowering the sensitivity, whereby the content of the electrophotographic photosensitive member can be reduced. Mechanical durability can also be improved. The content of the charge generating substance in the charge generating layer is 0.1 to 40% by weight based on the binder resin.
Is preferable, and 0.3 to 25% by weight is particularly preferable. 0.
If it is less than 1% by weight, sufficient sensitivity cannot be obtained, and 4
If it exceeds 0% by weight, the charge generation layer becomes brittle and the mechanical durability of the electrophotographic photosensitive member deteriorates.

To produce the electrophotographic photosensitive member of the present invention, a dispersion solution containing a charge generating substance, a hole transporting substance, a binder resin and a fluorene compound as an electron transporting substance is coated on a conductive substrate. The charge generation layer may be formed by drying, and then the charge transport layer may be laminated on the charge generation layer by a known method.

As the charge generating substance, the above-mentioned organic dyes and inorganic compounds can be used alone or in combination of several kinds thereof, and as the hole transporting substance, the above-mentioned donor compound can be used alone or in combination of several kinds thereof. can do.

The hole transport material is preferably used in an amount of 20% by weight or more based on the total composition of the charge generation layer.

As the fluorene compound, the fluorene compound represented by the general formula (1) is preferable, and these can be used alone or in combination of several kinds.

The fluorene compound is preferably used in an amount of 1 to 40% by weight based on the total composition of the charge generation layer.

As the binder resin, butyral resin, acrylic resin, cellulosic resin, silicone resin, polyester resin, polycarbonate resin, styrene resin, polyarylate resin, phenoxy resin, urethane resin, vinylidene fluoride resin, melamine. Resin, alkyd resin, epoxy resin, addition polymerization type resin such as phenol resin, polyaddition type resin, polycondensation type resin, and copolymer resin containing two or more of these repeating units, for example, vinyl chloride-vinyl acetate A copolymer, a styrene-butadiene copolymer, a vinylidene fluoride-trifluoroethylene copolymer, etc. can be used. The binder resin is preferably used in an amount of 30 to 70% by weight based on the total composition of the charge generation layer. The thickness of the charge generation layer is 0.5 to 50.
μm is preferable, and 1.0 to 20 μm is particularly preferable.

The charge transport layer laminated on the charge generation layer is composed of at least a charge transport material and a binder resin, and an additive may be added if necessary. As the charge transport material, either a hole transport material or an electron transport material can be used.

The above-mentioned donor compounds can be used alone or as a mixture of several kinds as the hole-transporting material, and as the electron-transporting material, in addition to the fluorene compound represented by the general formula (1), for example, , Quinone-based compounds, quinone-based vinylidene dinitrile compounds, fluorenone-based compounds, fluorenone-based vinylidene dinitrile compounds, π
An acceptor compound such as an electron compound, a π-electron compound having a cyano group, and a π-electron compound having a nitro group can be used.

Further, as the binder resin for the charge transport layer, those exemplified as the binder resin for the charge generation layer such as polycarbonate resin, polyarylate resin, styrene resin can be used. The content of the charge transport material in the charge transport layer is preferably 25 to 400 parts by weight, more preferably 50 to 200 parts by weight, based on 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably 5 to 60 μm, particularly preferably 10 to 30 μm. In the charge transport layer, an antifoaming agent, an antioxidant, and
Adhesion aids, plasticizers and the like can be added.

As the conductive substrate, those mentioned above can be used, and if necessary, an undercoat layer, an adhesive layer, a barrier layer or the like may be provided between the conductive substrate and the charge generation layer. . A charge generation layer or a charge transport layer, or an undercoat layer,
The adhesive layer, the barrier layer and the like can be coated by a known coating method such as a dipping coater, a calendar coater, a kiss coater, a gravure coater, a blade coater, a spray coater and a spin coater.

[0060]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 Fluorene compound (Exemplified compound No. 63 in Table 1) 1
g, nylon resin (CM8000, manufactured by Toray Industries, Inc.) 5 g is dissolved in ethyl alcohol 94 g, and aluminum 100
A 75 μm thick polyester film vapor-deposited to a thickness of 0Å was coated with a doctor blade and dried to form an undercoat layer having a thickness of 0.5 μm. Next, 1 g of the bisazo pigment having the following structural formula P-1 was added to butyral resin (ESREC BL-
S, manufactured by Sekisui Chemical Co., Ltd.) by ball milling with 10 g of a 5% by weight tetrahydrofuran solution and 9 g of tetrahydrofuran, and after milling, tetrahydrofuran is added to dilute it so that the solid content becomes 2% by weight. It was applied and dried to provide a charge generation layer having a film thickness of 1.0 μm.

[0062]

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Next, 6 g of a hole-transporting substance represented by the following structural formula D-1, 9 g of polycarbonate Z (manufactured by Teijin Chemicals),
Silicon oil (KF50, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.009
g was dissolved in 85 g of tetrahydrofuran, applied on the charge generation layer and dried to provide a charge transport layer having a thickness of 20 μm, and an undercoat layer, a charge generation layer and a charge transport layer were sequentially laminated on a conductive substrate. An electrophotographic photoreceptor was produced.

[0064]

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Example 2 In Example 1, as the fluorene compound, the exemplified compound No. 1 in Table 1 was used. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 33 was used.

Example 3 In Example 1, as the fluorene compound, the exemplified compound No. 1 in Table 1 was used. No. 63 is used, and X-type metal-free phthalocyanine (Fastogen B1ue 812) is used as a charge generating substance.
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 0BS, manufactured by Dainippon Ink and Chemicals, Inc. was used.

Comparative Example 1 An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the undercoat layer was not provided.

The electrophotographic photosensitive member thus produced was charged by corona discharge at -6 KV for 20 seconds using an electrostatic copying paper tester (SP-428) manufactured by Kawaguchi Electric Co., Ltd., and then darkened for 20 seconds. Attenuate, then adjust the illuminance on the surface of the photoreceptor to 20 lux, and
Irradiated for 0 seconds. The surface potential Vs (V) after being charged for 20 seconds, the surface potential V ₀ (V) after dark decay for 20 seconds, and the exposure required for V _{0 to} be 1/10 were measured under the above conditions continuously 500 times. The amount E _1/10 (lux · sec) and the surface potential V ₃₀ (V) after exposure for 30 seconds were measured. Table 1 shows the measurement results
It is shown in FIG.

[0069]

[Table 11]

As is clear from Table 11, the electrophotographic photosensitive members of the examples are superior in sensitivity to the electrophotographic photosensitive members of the comparative example, have a small residual potential in repeated use of the electrophotographic photosensitive member, and have a high sensitivity. The decrease of is also small.

Example 4 X-type metal-free phthalocyanine (Fastogen B1u)
e 8120BS, manufactured by Dainippon Ink and Chemicals, Inc., 0.3 g, and 10 g of a polycarbonate Z (manufactured by Teijin Chemicals Co., Ltd.) in 10% by weight tetrahydrofuran solution, 0.6 g of the hole transport substance represented by the structural formula D-1 and a fluorene compound (Table Tetrahydrofuran was added to a mill base prepared by ball milling together with 0.6 g of the exemplified compound No. 63 of 1) and stirred to prepare a coating solution of 6% by weight.
A charge-generating layer having a thickness of 5 μm was provided by coating with a doctor blade on a 75 μm-thick polyester film vapor-deposited to a thickness of 0Å and drying.

Then, 2 g of the hole transporting material represented by the structural formula D-1 and 3 of polycarbonate Z (manufactured by Teijin Chemicals Ltd.)
g and phenylmethyl-polysiloxane (KF50, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.002 g, and tetrahydrofuran 20 g
To prepare a coating solution, which was coated on the charge generation layer with a doctor blade and dried to laminate a charge transport layer having a film thickness of 18 μm to prepare an electrophotographic photoreceptor.

Example 5 In Example 4, as the fluorene compound, the exemplified compound No. 1 in Table 1 was used. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that 33 was used.

Comparative Example 2 An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the hole transport material represented by the structural formula D-1 and the fluorene compound were removed from the charge generation layer.

The electrophotographic photosensitive member thus manufactured was charged by corona discharge at +6 KV for 20 seconds using an electrostatic copying paper tester (SP-428) manufactured by Kawaguchi Electric Co., and further dark decay for 20 seconds. After that, the illuminance on the surface of the photoconductor is adjusted to 20 lux and the tungsten light is adjusted to 3
Irradiated for 0 seconds. Under the above conditions, the measurement was performed 100 times continuously, and the surface potential Vs (V) after charging for 20 seconds, the surface potential V ₀ (V) after dark decay for 20 seconds, and the exposure required for V ₀ to become 1/2 the amount E1 / 2 (lux · sec), V0 is the exposure amount required to be 1/10 E _1/10 (lux · sec) and 30
The surface potential V ₃₀ (V) after the second exposure was measured. The measurement results are shown in Table 3.

[0076]

[Table 12]

As is clear from Table 12, the electrophotographic photosensitive members of the examples have higher sensitivity and smaller residual potential than the electrophotographic photosensitive members of the comparative example, and the sensitivity is also improved in repeated use of the electrophotographic photosensitive members. Does not decrease and the residual potential is small.

[0078]

INDUSTRIAL APPLICABILITY According to the present invention, in a function-separated type electrophotographic photosensitive member having an undercoat layer, the sensitivity is high, the residual potential is small, and the durability of these characteristics is small even after repeated use. An excellent electrophotographic photosensitive member can be obtained.

Further, according to the present invention, the sensitivity is high, the residual potential is small, the variations in these characteristics are small even after repeated use, the electrophotographic characteristics are excellent in durability, and the mechanical durability is also good. In addition, it is possible to obtain a function-separated electrophotographic photosensitive member having excellent productivity.

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[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication G03G 5/06 319 G03G 5/06 319 // C07D 263/56 C07D 263/56 277/42 277 / 42 277/82 277/82

Claims (4)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive substrate, and a charge generation layer and a charge transport layer containing a hole transport substance, which are sequentially laminated on the conductive substrate. A fluorene compound is provided between the conductive substrate and the charge generation layer. An electrophotographic photoreceptor comprising an undercoat layer containing 2. An electrophotographic photoreceptor comprising a charge generation layer and a charge transport layer laminated on a conductive substrate, wherein the charge generation layer comprises at least a charge generation substance, a hole transport substance, an electron transport substance and a binder resin. An electrophotographic photoreceptor containing the electron transporting material, wherein the electron transporting material is a fluorene compound. 3. The fluorene compound is an electron transporting material represented by the following general formula (1):
Alternatively, the electrophotographic photosensitive member according to item 2. (Wherein R ₁ and R ₂ represent a fluoroalkoxycarbonyl group, m and n represent an integer of 0 to 4, and Z represents
Represents an oxygen atom, ═C (X) (Y) or ═N (W), X, Y
Is a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted heterocyclic group And W represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. ) 4. The electrophotographic photosensitive member according to claim 2, wherein the content of the charge generating substance in the charge generating layer is 0.1 to 40% by weight based on the binder resin.