JP2573369B2 - Electrophotographic photoreceptor and manufacturing method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used for an image forming apparatus such as a copying machine and a method for producing the same.

<Related Art> Recently, in an image forming apparatus such as a copying machine using a so-called Carlson process, a charge generating material that generates charges by light irradiation and a charge transporting material that transports generated charges are used in combination. By separating the charge generation function and the charge transport function, so-called function separation type,
It is widely used because it is easy to increase the sensitivity.

In the function-separated type photoreceptor, the photosensitive layer formed on the surface of the conductive substrate is an organic layer in which a binder resin contains a functional component such as the charge generation material or the charge transport material. The organic photoreceptor described above is preferably used because of a wide selection of materials, excellent productivity, and a high degree of freedom in functional design.

The organic photoreceptor includes a charge generation layer containing a charge generation material, a multi-layered organic photosensitive layer in which a charge transport layer containing a charge transport material is laminated, and a charge generation material and a charge transport material. Some have a single-layer type photosensitive layer contained in a binder resin, and among them, they can be easily manufactured with good yield, and they can use a negatively charged toner that is excellent in positive charge characteristics and easy to manufacture. Therefore, an organic photoreceptor having a single-layer type organic photosensitive layer is preferably used.

Further, recently, when an image forming process such as charging, exposure, and static elimination is repeatedly performed, the charge generation or the sensitivity reduction is prevented in order to prevent the single-layer type photosensitive layer from becoming fatigued and causing a decrease in charge amount or sensitivity. As a material and a charge transporting material, a perylene-based compound (charge-generating material) and an m-phenylenediamine-based compound (charge-transporting material) which are excellent in the above-described actions of preventing a decrease in the amount of charge and a decrease in sensitivity are used. An organic photoreceptor excellent in physical properties and contained in polycarbonate as a binder resin has been proposed.

<Problems to be Solved by the Invention> However, a single-layer type organic photosensitive layer containing the perylene-based compound and the m-phenylenediamine-based compound is particularly heated during operation of an image forming apparatus. When irradiated with a halogen lamp, sunlight, or the like in a state where the light is irradiated (usually around 60 ° C.), visible light contained in these lights causes a problem that sensitivity is reduced.

The present invention has been made in view of the above circumstances, and when repeatedly performing an image forming process, is excellent in the action of preventing a reduction in charge amount or sensitivity, and a perylene-based compound as a charge generating material. Another object of the present invention is to provide an electrophotographic photoreceptor containing an m-phenylenediamine compound as a charge transporting material and hardly causing a decrease in sensitivity (deterioration of visible light) by irradiation with visible light, and a process for producing the same.

<Means and Actions for Solving the Problems> In order to solve the above problems, the inventors studied the relationship between the glass transition temperature of the formed layer and the reduction in sensitivity.

That is, the visible light degradation is caused by the m-phenylenediamine-based compound being excited by its own visible light absorption or energy transfer from a visible light absorbing substance such as a perylene-based compound, causing a dimerization reaction or a decomposition reaction. ,
This is thought to be due to the change to a substance that becomes a carrier trap that lowers the sensitivity of the photoreceptor.However, the glass transition temperature of the layer mainly composed of polycarbonate is the heating temperature of the electrophotographic photoreceptor during operation or the like. If the temperature is lower than (60 ° C.), the layer undergoes a glass transition in the above-mentioned heating state,
It was presumed that the polycarbonate constituting this layer was likely to transmit the above-mentioned excitation energy, and would promote the dimerization reaction and decomposition reaction of the m-phenylenediamine-based compound.

Further, as described above, when the layer is heated to a glass transition temperature or higher, the difference in physical properties such as the coefficient of thermal expansion between the layer and the base increases, and the adhesion of the layer to the base decreases, A decrease in the conductivity between the layer and the base is also considered to be one of the causes of the decrease in sensitivity.

As a result of the above examination, if the glass transition temperature of the layer mainly composed of polycarbonate is 62 ° C. or higher, there is no possibility that the layer undergoes glass transition even in the above-mentioned heated state, and an image having no practical problem can be obtained. Based on this finding and this finding, the present invention has been completed. Therefore, the electrophotographic photoreceptor of the present invention has an electron having a layer containing a perylene-based compound as a charge generation material and an m-phenylenediamine-based compound as a charge transport material in a polycarbonate as a binder resin. In photoreceptors,
The glass transition temperature of the layer is at least 62 ° C., and the method for producing an electrophotographic photoreceptor of the present invention comprises: a polycarbonate as a binder resin, a perylene compound as a charge generation material, and a charge transport material. Layer containing m-phenylenediamine-based compound as
The glass transition temperature of the above layer is set to 62 ° C. or more by heat treatment for 0 minute or more.

 Hereinafter, the present invention will be described in detail.

The perylene compound contained in the photosensitive layer is represented by the following general formula [I], and the m-phenylenediamine compound is represented by the following general formula [II].

(However, R ^{1 to} R ⁴ in the above formula [I] each represent the same or different alkyl groups) (Wherein, R ^{5 to} R ⁹ in the above formula [II] represent the same or different groups selected from the group consisting of an alkyl group, an alkoxy group, a halogen atom and a hydrogen atom) As the perylene compound represented, R ^{1 to} R ⁴ in the formula (I) are an alkyl group having 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, Compounds that are an isobutyl group, a tert-butyl group, a pentyl group, or a hexyl group are mentioned as preferred ones.

Specifically, N, N'-di (3,5-dimethylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N '
-Di (3-methyl-5-ethylphenyl) perylene-3,
4,9,10-tetracarboxydiimide, N, N'-di (3,5-
(Diethylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3,5-dinolpropylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N '-Di (3,5-diisopropylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3-methyl-5-isopropylphenyl) perylene-
3,4,9,10-tetracarboxydiimide, N, N'-di (3,5
-Dinormalbutylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3,5-di-tert-
(Butylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3,5-dipentylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N '
-Di (3,5-dihexylphenyl) perylene-3,4,9,10
-Tetracarboxydiimide and the like, among which N, N'-di (3,5-dimethylphenyl) perylene-3,4,9,10-tetracarboxydiimide is preferred from the viewpoint of availability. No.

On the other hand, as the m-phenylenediamine compound represented by the general formula [II], R ^{5 to} R ⁹ in the formula [II] are hydrogen, a lower alkyl group having 1 to 6 carbon atoms, Compounds which are lower alkoxy groups or halogens of 6 are mentioned as preferred. Examples of the lower alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a tert-butyl group, a pentyl group, and a hexyl group.Examples of the lower alkoxy group include a methoxy group, An ethoxy group, a normal propoxy group, an isopropoxy group, a normal butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group are exemplified.

Specifically, N, N, N ', N'-tetraphenyl-1,3-phenylenediamine, N, N, N', N'-tetrakis (3-tolyl) -1,3-phenylenediamine, N , N, N ', N'-tetraphenyl-3,5-tolylenediamine, N, N, N', N'-tetrakis (3-tolyl) -3,5-tolylenediamine, N,
N, N ', N'-tetrakis (4-tolyl) -1,3-phenylenediamine, N, N, N', N'-tetrakis (4-tolyl)
-3,5-tolylenediamine, N, N, N ', N'-tetrakis (3-ethylphenyl) -1,3-phenylenediamine,
N, N, N ', N'-tetrakis (4-propylphenyl)-
1,3-phenylenediamine, N, N, N ', N'-tetraphenyl-5-methoxy-1,3-phenylenediamine, N, N-bis (3-tolyl) -N', N'-diphenyl- 1,3-phenylenediamine, N, N'-bis (4-tolyl) -N, N'-
Diphenyl-1,3-phenylenediamine, N, N'-bis (4-tolyl) -N, N'-bis (3-tolyl) -1,3-phenylenediamine, N, N'-bis (4-tolyl ) −N, N ′
-Bis (3-tolyl) -3,5-tolylenediamine, N, N '
-Bis (4-ethylphenyl) -N, N'-bis (3-ethylphenyl) -1,3-phenylenediamine, N, N'-bis (4-ethylphenyl) -N, N'-bis (3 -Ethylphenyl) -3,5-tolylenediamine, N, N, N ', N'-tetrakis (2,4,6-trimethylphenyl) -1,3-phenylenediamine, N, N, N', N '-Tetrakis (2,4,6-trimethylphenyl) -3,5-tolylenediamine, N, N, N',
N'-tetrakis (3,5-dimethylphenyl) -1,3-phenylenediamine, N, N, N ', N'-tetrakis (3,5-dimethylphenyl) -3,5-tolylenediamine, N, N, N ′,
N'-tetrakis (3,5-diethylphenyl) -1,3-phenylenediamine, N, N, N ', N'-tetrakis (3,5-diethylphenyl) -3,5-tolylenediamine, N, N, N ′,
N'-tetrakis (3-chlorophenyl) -1,3-phenylenediamine, N, N, N ', N'-tetrakis (3-bromophenyl) -1,3-phenylenediamine, N, N, N', N '-
Tetrakis (3-iodophenyl) -1,3-phenylenediamine, N, N, N ', N'-tetrakis (3-fluorophenyl) -1,3-phenylenediamine and the like are preferred.
Examples thereof include phenylenediamine compounds. And, among the above compounds, the group R ⁵ in the general formula (II)
-R ⁹ is a compound in which, among the benzene rings, a compound in which the nitrogen atom is bonded to the carbon at the meta position with respect to the carbon to which the nitrogen atom is bonded, or
The groups R ⁵ and R ⁹ are bonded to the carbon at the para-position to the carbon to which the nitrogen atom is bonded in the benzene ring, and the groups R ⁶ and R ⁸ are bonded to the nitrogen atom in the benzene ring The compound bonded to the carbon at the meta position with respect to the carbon that has been formed has a large molecular asymmetry, a small interaction between the molecules, and is difficult to crystallize.
It can be easily dispersed in a binder resin, and is included in the present invention as a more preferable one. In particular,
N, N, N ', N'-tetrakis (3-tolyl) -1,3-phenylenediamine, N, N'-bis (4-tolyl) -N, N'-bis (3-tolyl) -1, Compounds such as 3-phenylenediamine are exemplified as being more preferred.

Examples of the polycarbonate constituting the photosensitive layer together with the above-mentioned perylene compound and m-phenylenediamine compound include bisphenol Z represented by the following general formula [III].
Type polycarbonate can be used, and the following general formula [I
V], a normal bisphenol A-type polycarbonate or the like can also be used.

In addition, another binder resin may be used in combination with the specific layer as long as it does not affect the glass transition temperature of the specific layer. Examples of the other binder resin include a thermosetting silicone resin; an epoxy resin; a urethane resin; a curable acrylic resin; an alkyd resin; an unsaturated polyester resin; a diallyl phthalate resin; a phenol resin; a urea resin; a benzoguanamine resin; A styrene polymer; an acrylic polymer; a styrene-acrylic copolymer; polyethylene, an ethylene-vinyl acetate copolymer,
Olefin polymers such as chlorinated polyethylene, polypropylene, and ionomer; polyvinyl chloride;
Vinyl acetate copolymer; polyvinyl acetate; saturated polyester; polyamide; thermoplastic urethane resin; polyarylate; polysulfone; ketone resin; polyvinyl butyral; The binder resin is used for forming a surface protective layer formed on the photosensitive layer as required, in addition to the photosensitive layer.

The photosensitive layer containing each of the above components has a glass transition temperature of 62.
It must be at least ° C. The glass transition temperature of the photosensitive layer is 62
If the temperature is lower than 0 ° C., the amount of excitation energy transmitted to the m-phenylenediamine-based compound during light irradiation is too large, and a large amount of the m-phenylenediamine-based compound undergoes a dimerization reaction or a decomposition reaction. Of the deteriorated portion is remarkably reduced, and especially in a halftone image (gray image), the deteriorated portion is darkened to cause unevenness, and a practical image can be obtained. become unable.

As described above, to produce the electrophotographic photoreceptor of the present invention in which the glass transition temperature of the photosensitive layer is 62 ° C. or more,
By performing the heat treatment at the above-mentioned temperature for 30 minutes or more, the crystallinity of the polycarbonate in the photosensitive layer is increased, and the glass transition temperature thereof is increased. According to the manufacturing method of the present invention, the glass transition temperature of the photosensitive layer can be increased to 62 ° C. or higher by simply heating, so that the electrophotographic photosensitive member of the present invention can be easily manufactured without requiring a large-scale apparatus. It becomes possible.

In the production method of the present invention, the heat treatment temperature of the photosensitive layer is limited to 110 ° C. or more and the heat treatment time is limited to 30 minutes or more because the heat treatment temperature is less than 110 ° C. or the heat treatment time is less than 30 minutes. This is because the crystallinity of the polycarbonate cannot be sufficiently increased.

The heat treatment temperature is preferably 130 ° C. or lower in order to prevent sublimation, decomposition, and the like of the functional components such as the charge generation material and the charge transport material contained in the specific layer.

The heat treatment under the above heating conditions may be performed simultaneously with the solidification or curing of the photosensitive layer when forming a photosensitive layer by applying a coating solution containing at least a polycarbonate, a perylene-based compound, and an m-phenylenediamine-based compound. Alternatively, it may be performed on the already solidified or cured photosensitive layer.

Since the perylene compound has no spectral sensitivity on the long wavelength side, when combined with a halogen lamp having a large red spectral energy, the perylene compound has sensitivity on the long wavelength side in order to increase the sensitivity of the photoconductor. It is preferable to use another charge generating material such as X-type metal-free phthalocyanine.

As the X-type metal-free phthalocyanine, various ones can be used. In particular, the Bragg angle (2θ ± 0.
2 °), 7.5 °, 9.1 °, 16.7 °, 17.3 ° and 22.3 °
Those showing a strong diffraction peak are preferred.

The amount of the X-type metal-free phthalocyanine is not particularly limited, but is preferably in the range of 1.25 to 3.75 parts by weight based on 100 parts by weight of the perylene compound.
If the addition amount of the X-type metal-free phthalocyanine to 100 parts by weight of the perylene-based compound is less than 1.25 parts by weight, the sensitivity on the long wavelength side cannot be sufficiently improved, and if it exceeds 3.75 parts by weight, the sensitivity on the long wavelength side cannot be improved. There is a possibility that the spectral sensitivity is too high and the reproducibility of the red document is reduced.

Further, in addition to the above-mentioned perylene-based compound and X-type metal-free phthalocyanine, for example, α-S
e, powders of amorphous chalcogenides such as α-As ₂ Se ₃ and α-Se As Te, and powders of semiconductor materials such as amorphous silicon (α-Si); II-VI group microcrystals such as ZnO and CdS; pyrylium salts Azo compounds; bisazo compounds; α-type, β-type,
aluminum phthalocyanine having a crystal form such as γ-type,
Phthalocyanine compounds such as copper phthalocyanine and titanyl phthalocyanine; anthanthrone compounds; indigo compounds; triphenylmethane compounds; slen compounds; triidine compounds; pitazoline compounds; quinacridone compounds; Materials can be used in combination as needed.

In addition, it is preferable that the photosensitive layer usually contains, in addition to the m-phenylenediamine-based compound, another conventionally known charge transporting material (hereinafter, simply referred to as “other charge transporting material”). Other charge transporting materials contained in the photosensitive layer together with the m-phenylenediamine compound include:
Tetracyanoethylene; fluorenone compounds such as 2,4,7-trinitro-9-fluorenone; fluorene compounds such as 9-carbazolyliminofluorene; nitrated compounds such as dinitroanthracene; succinic anhydride; maleic anhydride; Dibromomaleic anhydride; triphenylmethane compound; 2,5-di (4-dimethylaminophenyl) -1,3,
Oxadiazole compounds such as 4-oxadiazole; 9
Styryl compounds such as-(4-diethylaminostyryl) anthracene; carbazole compounds such as poly-N-vinylcarbazole; pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline;
4,4 ', 4 "-tris (N, N-diphenylamino) triphenylamine, 3,3'-dimethyl-N, N, N', N'-tetrakis-4-methylphenyl (1,1'- Biphenyl) -4,4 '
Amine derivatives such as -diamine; conjugated unsaturated compounds such as 1,1-bis (4-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene; 4- (N, N-diethylamino) benzaldehyde-N, Hydrazone compounds such as N-diphenylhydrazone; indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds,
Nitrogen-containing cyclic compounds such as pyrazole compounds, pyrazoline compounds and triazole compounds; condensed polycyclic compounds and the like. Among the other charge transport materials,
The photoconductive polymer material such as poly-N-vinylcarbazole can also be used as a binder resin for the photosensitive layer.

The mixing ratio of the other charge transporting material and the m-phenylenediamine compound in the photosensitive layer is not particularly limited, but is in the range of 95: 5 to 25:75 by weight, particularly 80:20 to 5 by weight.
It is preferably within the range of 0:50. The mixing ratio of the other charge transporting material to the m-phenylenediamine compound is 95: 5.
Below, when the image forming process is repeated,
The effect of preventing a reduction in the amount of charge and a reduction in sensitivity becomes insufficient. Conversely, if the compounding ratio exceeds 25:75, the sensitivity of the photoconductor may become insufficient.

The content of the charge generating material relative to 100 parts by weight of the binder resin in the photosensitive layer comprising the above components is preferably in the range of 2 to 20 parts by weight, particularly preferably in the range of 3 to 15 parts by weight. Further, the content of the other charge transporting material with respect to 100 parts by weight of the binder resin is preferably in the range of 40 to 200 parts by weight, particularly preferably in the range of 50 to 100 parts by weight. When the content of the charge generating material is less than 2 parts by weight or the content of the other charge transporting materials is less than 40 parts by weight, the sensitivity of the photoconductor may be insufficient or the residual potential may be increased. . On the other hand, when the content of the charge generation material exceeds 20 parts by weight, or
If the content of the other charge transporting material exceeds 200 parts by weight, the abrasion resistance of the photoconductor may be insufficient.

The thickness of the photosensitive layer is not particularly limited, but is comparable to that of a conventional single-layer organic photosensitive layer, that is, 10 to 50 μm, particularly
Preferably it is in the range of 15 to 25 μm.

On the photosensitive layer, as described above, the binder resin was used as a main component, and as necessary, additives such as a conductivity-imparting material and a benzoquinone-based ultraviolet absorber were appropriately contained. A surface protective layer can be laminated. The thickness of the surface protective layer is preferably in the range of 0.1 to 10 μm, particularly preferably in the range of 2 to 5 μm.

When an antioxidant is used in combination with the photosensitive layer and the surface protective layer, it is possible to prevent deterioration of a functional component such as a charge transport material having a structure susceptible to oxidation due to oxidation.

As the antioxidant, 2,6-di-tert-butyl-
p-cresol, triethylene glycol-bis [3-
(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], pentane Erythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-) Hydroxyphenyl) propionate], 2,2-thiobis (4-
Methyl-6-tert-butylphenol), N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,
Examples include phenolic antioxidants such as 4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene.

The conductive substrate on which the photosensitive layer is formed on the surface is formed in an appropriate shape such as a sheet shape or a drum shape according to the mechanism and structure of the image forming apparatus into which the electrophotographic photosensitive member is incorporated.

The conductive substrate may be entirely formed of a conductive material such as a metal, or the substrate itself may be formed of a structural material having no conductivity, and may be provided with conductivity on its surface. good.

The entirety of the conductive substrate is made of a conductive material, and as the conductive material used in the former case, alumite-treated or untreated aluminum, copper, tin,
Platinum, gold, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium,
Metal materials such as stainless steel and brass are preferable, and particularly, aluminum subjected to anodic oxidation by the alumite sulfate method and sealed with nickel acetate is preferably used.

On the other hand, in the latter case of imparting conductivity to the surface of a substrate made of a structural material having no conductivity, the above-described metal or aluminum iodide may be applied to the surface of a synthetic resin substrate or a glass substrate. A structure in which a thin film made of a conductive material such as tin oxide, indium oxide, or the like is formed by a known film forming method such as a vacuum evaporation method or a wet plating method; A structure in which a film of a material or the like is laminated, a structure in which a substance imparting conductivity is injected into the surface of the synthetic resin base or the glass base, or the like can be employed.

The conductive substrate may be subjected to a surface treatment with a surface treatment agent such as a silane coupling agent or a titanium coupling agent, as necessary, to increase the adhesion to the photosensitive layer.

For the photosensitive layer and the surface protective layer described above, a coating solution for both layers containing the above-described components is prepared, and these coating solutions are sequentially applied to the conductive substrate for each layer, and dried or cured. By doing so, lamination can be formed.

In preparing the coating solution, various solvents can be used depending on the type of the binder resin or the like to be used. Examples of the solvent include aliphatic hydrocarbons such as n-hexane, octane, and cyclohexane; benzene, xylene,
Aromatic hydrocarbons such as toluene; halogenated hydrocarbons such as dichloromethane, carbon tetrachloride, chlorobenzene, methylene chloride; methyl alcohol, ethyl alcohol, isopropyl alcohol, allyl alcohol, cyclopentanol, benzyl alcohol, furfuryl alcohol, diacetone Alcohols such as alcohols; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone;
Various solvents such as esters such as ethyl acetate and methyl acetate; dimethylformamide; dimethyl sulfoxide, and the like, may be used alone or as a mixture of two or more. When preparing the coating liquid, a surfactant, a leveling agent, and the like may be used in combination in order to improve dispersibility, coatability, and the like.

The coating solution can be prepared by a conventional method, for example, using a mixer, a ball mill, a paint shaker, a sand mill, an attritor, an ultrasonic disperser, or the like.

<Example> Hereinafter, the present invention will be described in more detail with reference to examples.

Examples 1 to 3, Comparative Examples 1 and 2 100 parts by weight of poly- (4,4'-cyclohexylidenediphenyl) carbonate (manufactured by Mitsubishi Gas Chemical Company, trade name Z-200) as a binder resin, a charge generating material 5 parts by weight of N, N'-di (3,5-dimethylphenyl) perylene 3,4,9,10-tetracafboxodiimide and 0.2 part by weight of an X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) 3,3'-dimethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,
70 parts by weight of 4'-diamine and 30 parts by weight of N, N, N ', N'-tetrakis (3-tolyl) -1,3-phenylenediamine,
5 parts by weight of 2,6-di-tert-butyl-p-cresol (manufactured by Kawaguchi Chemical Co., Ltd., trade name Antage BHT) as an antioxidant was mixed and dispersed with a predetermined amount of tetrahydrofuran in an ultrasonic disperser to form a single layer. A coating solution for a photosensitive layer was prepared. This coating solution was applied to an aluminum tube having an outer diameter of 78 mm and a length of 344 mm, dried at room temperature, and then heat-treated in a dark place under the heat treatment conditions shown in Table 1 to obtain a glass transition temperature shown in the table. And a drum-type electrophotographic photosensitive member having a single-layer photosensitive layer having a thickness of about 22 μm was prepared. The glass transition temperature was measured by differential scanning calorimetry (DSC method).

The following tests were performed on the electrophotographic photoreceptors produced in the above Examples and Comparative Examples.

Initial surface potential measurement Each of the above electrophotographic photoreceptors is loaded into an electrostatic copying tester (Gentec Cynthia 30M, manufactured by Gentec), the surface thereof is charged positively, and the surface potential V ₁ sp (V) is measured. did.

Measurement of half-reduction exposure amount and residual potential Each electrophotographic photosensitive member in the charged state is exposed using a halogen lamp as an exposure light source of the electrostatic copying test apparatus, and the surface potential V ₁ sp (V) is reduced to half. The half-exposure amount E1 / 2 (μJ / cm ² ) was calculated.

Further, the surface potential 0.19 seconds after the start of the exposure was measured as a residual potential V ₁ rp (V).

Surface potential change value and residual potential change value measurement after irradiation with visible light At two points on each of the electrophotographic photoreceptors, surface potentials V _1a sp, V _1b sp, and
After measuring the residual potentials V _1a rp and V _1b rp [or more, unit (V)], the electrophotographic photosensitive member was preheated to 60 ° C. in a dark place.
After storing for 20 minutes, while keeping the temperature at 60 ° C., the V _1b side of the two points is masked with a light-shielding body, and a yellow fluorescent lamp (trade name: National 1500 lux using colored fluorescent lamp FL20SYF, 20W)
For 20 minutes. Then, the exposed electrophotographic photoreceptor is left in a dark place at room temperature for 30 minutes, cooled, and then loaded into an electrostatic copying test apparatus (Gentec Cynthia 30M, manufactured by Gentec Corporation), and the surface thereof is correctly adjusted After charging, the two surface potentials V _2a sp (exposure side) and V _2b sp
(Light blocking side), residual potential V _2a rp (exposure side), V _2b
rp (light shielding side) [the unit (V)] was measured.

Based on the above measured values, the surface potential change value ΔV _1-2 sp (V) after irradiation with visible light was calculated using the following equation (a),
The residual potential change value ΔV _1-2 rp (V) after visible light irradiation was calculated using the following equation (b).

ΔVs.p. = (V _2a sp−V _1a sp) − (V _2b sp−V _1b sp)… (a)
ΔVr.p. = (V _2a rp−V _1a rp) − (V _2b rp−V _1b rp) (b)
Practical test Each of the electrophotographic photoreceptors after irradiation with visible light was loaded into a copying machine (DC-1655, manufactured by Mita Kogyo Co., Ltd.), and the halftone document was copied, and the density unevenness of the image was visually observed. , A sample without density unevenness was evaluated as ○, and a sample with density unevenness was evaluated as ×.
Was evaluated.

 The results are shown in the following table.

From the results in the above table, the glass transition temperature of the single-layer photosensitive layer is
All of the electrophotographic photoreceptors of Examples 1 to 3 having a temperature of 62 ° C. or higher have a glass transition temperature of 20 V or less in the amount of change in surface potential due to irradiation with visible light as compared with Comparative Examples 1 and 2 in which the glass transition temperature is lower than the above value.
The amount of change in the residual potential is as small as 20 V or less.
It was found that the electrophotographic photosensitive members of Examples 1 to 3 were hardly deteriorated by visible light.

<Effect of the Invention> The electrophotographic photoreceptor of the present invention is configured as described above, and when repeatedly performing an image forming process, a perylene-based compound having an excellent action of preventing a decrease in charge amount or a decrease in sensitivity, and the like. Since the glass transition temperature of the photosensitive layer containing the m-phenylenediamine-based compound is 62 ° C. or higher, particularly when the photosensitive member is heated, such as during operation of an image forming apparatus, a halogen lamp or sunlight The sensitivity is hardly reduced even if the light including the visible light is irradiated.

Further, according to the method of manufacturing the electrophotographic photoreceptor of the present invention, the glass transition temperature of the photosensitive layer can be set to 62 ° C. or higher by simply heating the photosensitive layer. Can be manufactured.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Keizo Kimoto 1-2-2, Tamazo, Chuo-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. (56) References JP-A-1-142462 (JP, A)

Claims (2)

(57) [Claims] (1) In a polycarbonate as a binder resin,
In an electrophotographic photoreceptor provided with a layer containing a perylene compound as a charge generating material and an m-phenylenediamine compound as a charge transport material, the glass transition temperature of the layer is at least 62 ° C. Electrophotographic photoreceptor. 2. In a polycarbonate as a binder resin,
A layer containing a perylene-based compound as a charge generating material and an m-phenylenediamine-based compound as a charge transporting material is heat-treated at a temperature of 110 ° C. or more for 30 minutes or more, and the glass transition temperature of the layer is set to 62 ° C. or more. A method for producing an electrophotographic photoreceptor, comprising: