JPS6087335A - Composite type electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain good sensitivity over a wide wavelength range including the emission wavelength region of a semiconductor laser by using tau-type and/or eta- type metal-free phthalocyanine as an electrostatic charge generating material and a specified compd. as a charge transfer material. CONSTITUTION:A layer contg. a charge generatng material and a layer contg. a charge transfer material are formed on a conductive substrate to obtain a composite type electrophotographic sensitive body. As the charge generating material, metal-free phthalocyanine of a type selected from tau-type, tau'-type, eta-type, and eta'-type is used, and as the charge transfer material, compds. represented by the formula, are used, in which R1, R2 are each alkyl, aralkyl, or aryl, and X is an aromatic heterocyclic group. Such a composite type photosensitive body is obtained, e.g., by forming a layer contg. the charge generating material on a conductive substrate and on this layer a layer contg. the charge transfer material or it may have a reverse constitution, or both materials may be contained in one layer. The use of a combination of such a charge generating and charge transfer materials enhances sensitivity even in a long wavelength region, and the obtained photosensitive body is especially suitable for a semiconductor laser printer using a semiconductor laser as a light source.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a photoreceptor that is effective for image creation by electrophotography, and particularly relates to a charge-generating material and a charge-transporting material that have high sensitivity even to long wavelength light. The present invention relates to a composite type electrophotographic photoreceptor comprising:

[Background of the invention]

Conventionally, as a charge generating material for a composite type electrophotographic photoreceptor, organic No.
Monoazo dyes, disazo dyes and squaric acid derivative dyes soluble in amines, quinocyanine pigments shown in JP-A-53-42830 and JP-A-53-41230, quinocyanine pigments shown in JP-A-51-11763 Many organic materials such as copper phthalocyanine pigments have been proposed. In addition, the tellurium-arsenic-glassy selenium series shown in Japanese Patent Publication No. 50-15137, Japanese Patent Publication No. 49-14272
Polymers having imide bonds and inorganic substances such as amorphous selenium have also been proposed. On the other hand, as the charge transporting substance, Japanese Patent Application Laid-Open No. 52-77730, Japanese Patent Application Laid-open No. 5
Poly-N-vinylcarbazole series shown in JP-A-2-753929, etc., pyrazoline derivatives shown in JP-A-49-105537, trinitrofluorenone shown in JP-A-46-4484, JP-A-53-301.
Various nitro- and cyano-substituted compounds shown in the above publication are presented. Electrophotographic photoreceptors using these materials all have good electrophotographic properties, but these photoreceptors exhibit high sensitivity to visible light in the -400 to 700 nm wavelength range, and are highly sensitive to near-infrared light (wavelength 750 nm). Above), there was no sensitivity at all, and even if there was sensitivity, it was low sensitivity, so it could not be used as a photoreceptor for electrophotography using near-infrared light as a light source (e.g., semiconductor laser). It had the following drawback.

In recent years, as a type of high-speed printer, a printing method using an electrophotographic method using a laser as a light source has been devised. Although it varies depending on the laser used as a light source, the percentage
It is desired to develop an electrophotographic photoreceptor that has high sensitivity to specific wavelengths. In particular, when a semiconductor laser is used as a light source, the light source section can be made very small, making it possible to miniaturize printers and significantly reduce power consumption, which is attracting a lot of attention. However, since the oscillation wavelength of a semiconductor laser is usually a long wavelength of 770 nm or more, the electrophotographic photoreceptor described above cannot be used.

[Purpose of the invention]

The purpose of the present invention is to overcome the drawbacks of conventional electrophotographic photoreceptors, and to provide an extremely wide range of wavelengths (500 to 825 runs).
The object of the present invention is to provide a composite type electrophotographic photoreceptor having high sensitivity in the oscillation wavelength range of a semiconductor laser.

[Summary of the invention]

The charge generating material is required to form electrons and holes by light passing through the charge transport layer, and to inject the generated holes (or electrons) into the charge transport layer by the total electric field. I can come out. In addition, the charge transporting material must meet various conditions, such as being able to effectively inject photocarriers generated in the stain-generating material by light irradiation, and having an appropriate absorption range that does not interfere with all the wavelengths absorbed by the charge-generating material. It is extremely difficult to create the necessary and good materials. There is a clear correlation between the effective injection of optical carriers and the ionization potential of the charge transport material. For example, research results have shown that when electrons are carriers, the ionization potential of the charge transport material needs to be higher than that of the charge transport material, and conversely, when holes are the carriers, it needs to be lower. .

On the other hand, the wavelength range to which the photoreceptor is sensitive depends on the absorption wavelength range of the charge-generating material, as long as the charge-transporting material used does not completely block the light absorbed by the charge-generating material.

Many studies have been conducted on long-wavelength absorbing charge-generating substances. For example, S that has a high sensitivity in the visible range
A new method of adding a sensitizer to materials such as e and CdF3 to make the wavelength longer is known, but it does not have sufficient environmental resistance against temperature and humidity, and is highly toxic. However, it cannot be put into practical use.

Many types of organic light guides are known, but their sensitivity is usually limited to a visible light region of 700 nm or less, and there are few materials that exceed this range.

Among these, it is known that phthalocyanine compounds, which are one of the organic photoconductive compounds, have an absorption wavelength range that extends to longer wavelengths than other compounds. Although not necessarily all, there is no money Piru or pJB.

Lj+ K, Mg, V, Mn, Fe, Co, Ni.

Cu, Zn, Ga, Ge, At, Ru, Lu.

Phthalocyanine containing gold stripes such as PT and its derivatives have properties other than photoconductivity, and are disclosed in Japanese Patent Publication No. 40-10787゜49-4.
338.50-34414.50-32623゜52-
1667.53-2780.53-19933゜47-
11798.50-27730.44-12671゜4
6-30035.49-17535.48-34189
゜44-14106 Publications 15 or U.S. Patent No. 3.357.989.3.492.308%3.895
．． 944.

3.640,710% No. 3,816,118, etc., it is used in electrophotographic photoreceptors or parts thereof, and many of them have a sensitive wavelength range of 700 nm or more. However, among materials that have properties that can be used practically as electrophotographic photoreceptors, that is, weather resistance, storage stability, mechanical strength, productivity, economic efficiency, etc. in addition to photoconductivity, 790 nm or more I feel high enough to
Very few are known to have t.

Based on the above-mentioned known facts, the present inventors conducted extensive studies focusing on %7 cyanine compounds, and as a result, discovered an extremely suitable combination of a charge-generating substance and a charge-transporting substance as shown in the present invention. Ta.

The present invention uses τ type and τ' type as charge generating substances.

The present invention relates to a composite type electrophotographic photoreceptor using a metal-free phthalocyanine selected from η type and η' type and using a compound represented by the following structural formula (A) as a charge transporting substance.

□2/ In the formula, R1 and R2 represent an alkyl group, an aralkyl group, or an aryl group that may have a substituent, and X represents an aromatic heterocyclic group that may have a substituent. Some of these compounds are listed below by their full structural formulas.

R3 Furthermore, the τ-type metal-free phthalocyanine in the present invention is defined as follows. That is, Black angle (2θ±0.2
degree) is 7.2.9.2.16.8.17.4°20.4
and has a strong X-ray diffraction pattern of 20.9.

In particular, the infrared absorption spectrum is 700 to 760 cwr-
'i
, 1320 to 1340♂ with two absorption bands of approximately equal intensity and a characteristic absorption at 3288±3 cm-''.

τ′ type gold metal phthalocyanine is defined as follows.

That is, for the X-rays of 1541 people of CuKυNi, the Black angle (2θ±0.2 degrees) is 7.59.1.16.
8.17.3.20.3.20.8.21.4 and 27
．． This is a new metal-free phthalocyanine crystal polymorph with a strong X-ray diffraction pattern of 4. In particular, the infrared absorption spectrum is 751±2or between 700 and 760 cm""! −”
The four strongest absorption bands are 1320 to 1340 crn.
- Two ELs between the two have absorption bands of the same intensity at 3297±
A material having a characteristic absorption at 3 m-1 is desirable.

η type metal phthalocyanine is defined as follows. That is, 100 parts by weight of metal-free phthalocyanine and 50 parts by weight of a mixture of one or more of metal-free phthalocyanine containing a substituent on the benzene nucleus, a phthalocyanine nitrogen isomer or metal phthalocyanine which may have a substituent on the pentene nucleus. The infrared absorption spectrum is 753 ± 1 c between 700 and 760 cm - indigo.
The four absorption bands with the strongest rn-' are 1320 to 134.
Between 0crrr1, two absorption bands 32 with approximately the same intensity as tl
It has a characteristic absorption at 85±5 an-''.

According to the study by the present inventors, the black angle (2θ±0.2 degrees) of η type metal phthalocyanine is ? , 6.9
．． 2. 16.8. Examples include those having an X# diffraction pattern with strong peaks at 17.4 and 28.5.

η'-type gold-free phthalocyanine is defined as follows. That is, 100 parts by weight of metal-free phthalocyanine and 50 parts by weight of a mixture of one or more of metal-free phthalocyanine having a substituent on the benzene nucleus, a phthalocyanine isoconstructor or metal phthalocyanine which may have a substituent on the benzene nucleus. 753±1a with an infrared absorption spectrum between 700 and 760cm-''
The four absorption bands with the strongest n″′l are 1320 to 134
Two absorption bands of almost equal strength between 0 crl 'i, 32
It is a novel metal-free phthalocyanine crystal polymorph having a characteristic absorption at 97±5c1n-1. According to the study of the present inventor, the black angle (2θ±0.2 degrees) of η' type gold metal phthalocyanine is 7.5, 9.1, 16.8.
゜17.3, 20.3, 20.8, 21.4 and 27.
4 has an X-ray diffraction pattern showing a strong peak, and 7.
．． 5.9.1.16.8.17.3.20.3.20.
It is desirable to have an X-ray diffraction pattern showing strong peaks at 8°21.4, 22.1, 27.4 and 28.5.

In addition, all metal-free phthalocyanines of τ type, η type, and η' type have extreme values in the photosensitive wavelength range of 790 to 810 n.
It is in the range of m.

The τ type and τ' type gold metal phthalocyanine used in the present invention are produced in the following manner. That is, a metal-free phthalocyanine having a τ'' crystal form is obtained by milling the α-type metal-free phthalocyanine at a temperature of 50 to 180 C, preferably 60 to 130 C, for a time sufficient to convert the crystals using a mechanical strain blade. is created.

The α-type phthalocyanine used in the present invention is a “phthalocyanine compound” by Moser and Torts (Mo5er
and Thomas ” Phthalocyani
For example, metal-free phthalocyanines are metal phthalocyanines that can be demetallized with acids such as sulfuric acid, such as lithium phthalocyanine, sodium phthalocyanine, calcium phthalocyanine, and magnesium phthalocyanine. Those made directly from phthalodinitrile, aminoiminoisoindolenine, alkoxyiminoisoindolenine, etc. are used by acid treatment of metal phthalocyanine containing phthalocyanine, etc. In this way, already well-known methods are used. The metal-free phthalocyanine gold obtained by the above method is dissolved in sulfuric acid or made into a sulfate, preferably at 5C or less, and then poured into water or ice water to be reprecipitated or hydrolyzed to obtain α-type metal-free phthalocyanine.

At this time, if an inorganic pigment is dissolved or dispersed in sulfuric acid or a reprecipitation solution, an α-type metal-free phthalocyanine containing an inorganic pigment is obtained. The inorganic pigment may be a wastewater-soluble powder that can be used as a color filler, such as titanium white.

In addition to zinc white carbon, calcium carbonate, etc., it can be used in many ways as a powder. Examples include metal powder 9 alumina, iron oxide powder, and kaolin.

The X-type gold-free striped phthalocyanine that contains this inorganic pigment is much more likely to be ground up when turning it into a pigment, compared to one that does not contain it.
Easy to make into fine particles, saving labor.

Effective and necessary for energy saving.

The α-type metal-free phthalocyanine subjected to such treatment is preferably used in a dry state, but it can also be used in the form of a water paste. Dispersion media for stirring and mixing may be those commonly used for pigment dispersion, emulsification, and the like, such as glass beads, steel beads, alumina balls, and flint stones. However, distributed media is not necessarily required. As the grinding aid, those commonly used as grinding aids for pigments may be used, and examples thereof include common salt, sodium bicarbonate, and sulfur salt. However, this grinding aid is also not necessarily required.

If a solvent is required during stirring, mixing, or grinding, it may be liquid at the temperature during stirring, mixing, or grinding, such as an alcoholic solvent, such as glycerin.

It is preferable to select one or more from the group of ethylene glycol, diethylene glycol or polyethylene glycol solvents, cellosolve solvents such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ketone solvents, and ester ketone solvents.

Typical devices used in the crystal transition process include general stirring devices such as homomixers,
There are dispersers, agitators, stirrers or kneaders, Banbury mixers, ball mills, sand mills, attritors, etc.

The temperature range in the crystal transition step of the present invention is 50 to 1so
C, preferably within the temperature range of 60 to 130C.

It is also an effective method to use crystal nuclei as in the usual crystal transition process.

α-type phthalocyanine used in the production of α-type and η′-type gold metal phthalocyanine used in the present invention and metal-free phthalocyanine having a substituent on the benzene nucleus, or even if the benzene nucleus has a substituent, the phthalocyanine nitrogen is more The structure or metal phthalocyanine is the "phthalocyanine compound" (Mose
randThomes ” Phthalocyani
ne Compounds") and other suitable methods. For example,
α-type metal-free phthalocyanine can also be obtained by the same formulation as described above, and may also contain other inorganic pigments.

In addition, various phthalocyanine nitrogen isoconstructs (D
Examples of phthalocyanines include copper tetrapyridinoborphyrazine in which one or more of the benzene nuclei of phthalocyanine are replaced with all quinoline nuclei, and metal phthalocyanines include copper, nickel, cobalt, zinc, tin, aluminum, etc. Various types can be mentioned.

Also, examples of substituents include amine group and nitro group.

Alkyl group, alkoxy group, cyano group, mercapto group,
It includes halogen atoms, and relatively simple examples include sulfonic acid groups, carboxylic acid groups, or metal salts thereof, ammonium salts, and amine salts. Furthermore, various substituents can be introduced to the benzene nucleus via an alkylene group, a sulfonyl group, a carbonyl group, an imino group, etc., and these are conventionally known in the technical field of phthalocyanine pigments as aggregation inhibitors or crystal conversion inhibitors. For example, US Pat. No. 3,973,981,
4088507) or unknown ones. Known methods for introducing each substituent will be omitted. In addition, things that are not publicly known are described as reference examples in the examples.

In the present invention, the mixing ratio of α-type metal-free phthalocyanine and metal-free phthalocyanine having a substituent group on the benzene nucleus, or a phthalocyanine nitrogen isomer or metal phthalocyanine which may have a substituent group on the benzene nucleus is Zoo1.
It may be 50 (weight ratio) or more, but preferably 100
/30 to 10010.1 (weight ratio). If the ratio exceeds this ratio, the resulting α-type and η'-type rafterthalocyanine will be less suitable as a pigment because it is prone to bleeding.

In the present invention, mixing in the above-mentioned ratio may be done by simply mixing, or by mixing before pasting the α-type metal-free phthalocyanine all over acid. The method of stirring or milling the mixture thus mixed may be the one normally used for dispersing, emulsifying, or mixing pigments, and examples of dispersion media for stirring or mixing include glass beads, steel beads, alumina balls, flint, etc. Although it may seem obvious, two-dispersion media is not necessarily required.

The grinding aid, the solvent used during crosstalk, the materials and equipment used in the crystal transition process are the same as in the case of the τ-type and r'-type metal-free phthalocyanine described above.

The temperature range in the α type and η' type gold metal phthalocyanine crystal transition step is 30 to 220 C, preferably 60 to 220 C.
Perform within a temperature range of 130C. At higher temperatures, it is easy to transition to the β form, and at lower temperatures, it takes time to transition to the α and η' forms. It is also an effective method to use crystal nuclei as in the usual crystal transition process.

It is not clear why the combination of a charge generating material and a charge transporting material of the present invention is preferable. Since high sensitivity is obtained during e-charging, it is expected that hole injection from the charge-generating substance to the charge-transporting substance is performed efficiently.

The nuclear tray-shaped photoreceptor for electrophotography of the present invention can be produced by applying h'hii! on a conductive support. A layer of r-generating material is formed, and an entire layer of charge transporting material is formed thereon.

The method for forming the charge generating material layer is the τ type.

A system containing at least one type of τ′ type, η type, η′ type metal-free phthalocyanine and optionally mixed with a binder resin is milled into fine particles (particle size of 5 μm or less,
In particular, the entire coating solution can be prepared by pulverizing and mixing the particles (particularly 1 μm or less) and forming a coating by coating.

The thickness of the charge-generating substance layer varies depending on the required sensitivity and the mixing ratio of the τ-type metal-free phthalocyanine and the binder resin, but it is usually 20 μm or less, and preferably 0.5 to 3 μm.
Not only does sensitivity decrease as the film thickness increases, but also the film loses its flexibility and peels off. Also,
Charge generating substance and binding agent?・The blending ratio of the former is 1 fat to the latter 4. A content of less than a part is good, and if the content exceeds this amount, the sensitivity tends to gradually decrease.

Further, the formation of a layer of a charge transporting substance is also performed by coating.

The charge transport material layer requires a binder resin to provide the film with mechanical strength. Using an organic solvent that can dissolve both the charge transport substance and the binder resin, a solution gold coating solution is prepared by dissolving both the charge transport substance and the binder resin. The thickness of the charge transport material layer is determined by the charging characteristics required for the photoreceptor.
, usually 5 to 100 μm, preferably 8 to 30 μm. Further, it is appropriate that the charge transport material and the binder resin be mixed in a range of 1 part by weight of the former to 05 to 4 parts by weight of the latter.

The binder resin used in the layer of charge generating material and charge transporting material includes known electrophotographic binders such as phenolic resin, area resin, melamine resin, furan resin, epoxy resin, silicone resin, vinyl chloride and vinyl acetate resin. Copolymer, xylene resin, toluene resin.

Urethane resins, vinyl acetate-methacrylic copolymers, acrylic resins, polycarbonate resins, polyester resins, cellulose derivatives, etc. are appropriately selected and used. In history, poly-N-vinylcarbasol, which exhibits photoconductivity,
Carbazole monkeys such as -9-IP-vinylphenyl)anthracene, polymers having an anthracene ring in the side chain, other heterogeneous compounds such as pyrazoline term, dibenzomooffene term, etc.
Molecules having aromatic compounds in their side chains can also be used as binder resins.

In the present invention, it is possible to add surfactants and plasticizers to the charge generating material layer and the charge transporting material layer as necessary, and by adding these agents, mechanical properties such as P11 oiliness and abrasion resistance can be improved. Electrophotographic properties can be improved by improving physical properties such as physical properties, film-forming flexibility, and fractional properties of the material.

Electrocardiographic supports include brass, aluminum, gold,
Copper, etc. are used, and these have appropriate thickness.

It may be a rigid or flexible sheet, a thin plate, cylindrical, or covered with a thin layer of plastic. It may also be a metal coating, a metal plastic sheet, a glass coated with a thin layer of aluminum iodide, steel iodide, indicum oxide or tin oxide. It is generally desirable that the support itself be conductive, rich in conductive surfaces, and strong enough to be handled.

The composite type electrophotographic photoreceptor of the present invention exhibits high sensitivity when charged with e-electrification, and has a particularly remarkable feature in the photosensitive wavelength range, especially 7
All sensitivity peaks are shown between 90 and 810 nm. This point is the reason why the photoreceptor of the present invention is suitable for use in semiconductor lasers.

[Embodiments of the invention]

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples.

Example I T-type metalless phthalocyanine (manufactured by Toyo Ingi Co., Ltd.).

Average particle size: φ0.3 x 1 μm) 1 part by weight, modified silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., KR-5221゜solid content 6
0%) 2 parts by weight, methylphenylsiloxane compound (
Shin-Etsu Chemical Co., Ltd., KP-323) 0.005 Heavy Grain and 37 parts by weight of tetrahydrofuran were kneaded in a ball mill for about 5 hours to prepare a coating liquid for a charge generation layer. Then the thickness is 10
The above-mentioned adjustment solution was applied to aluminum foil of 0 μm2 size 70 x 100 mm square using an automatic applicator (manufactured by Toyo Kozueki Co., Ltd.), and dried at 1301 for 2 hours to form a layer of charge-generating substance.Thickness of this layer is 0.5 μm.

Next, 1 part of a bulk carrier substance IM of the following structural formula, a polycarbonate resin manufactured by CGE Co., Ltd., Lexan 141-111) 0
．． 5 to 5 parts by weight, methylphenylsiloxane compound K
P-3230,001 to 0.007 parts by weight is dissolved in 20 to 50 parts by weight of a mixture of methylene chloride and 1,2-dichloroethane in a volume ratio of 40/60, and the charge transport substance and binder resin (polycarbonate) are mixed together. Distribution ratio is 1/0.5,
1/1, 1/2.

1/3.1/4.115 charge transport) - 6 types of coating liquids were prepared; this coating liquid was applied onto the layer of the charge generating material using an automatic applicator and dried at 100C for 2 hours. to form a layer of charge transport material. In each case, the thickness of the charge transport substance layer was 15 μm.

The electrophotographic properties of the above six types of composite electrophotographic photoreceptors were measured using an electrostatic recording paper tester (manufactured by Kawaguchi Electric Co., Ltd., Model 5P-428).

The measurement was performed in dynamic mode with e5KV corona charging for a total of 10 seconds, and after being left in a dark place for 30 seconds, exposure was performed using a red phosphor lamp. During this time, the surface potential of the photoreceptor is recorded with a total recorder, and the potential V after corona charging is completed, is the half-reduced exposure amount E so (tx=a ) was read. The results are shown in Table 1.

Table 1 As shown, the Eso tends to deteriorate as the binder resin component in the charge transport material layer increases.

Example 2 τ′-type metal phthalocyanine manufactured by Toyo Ink Co., Ltd.) IM parts by weight Butyral resin (Union Car) manufactured by Kuito Co., Ltd., XY
HL) 1 part by weight was mixed with xylene as a solvent to make a 6% by weight solution, and kneaded in a ball mill for 5 hours to obtain a charge generating material layer in the same manner as in Example 1.

Next, 1 part by weight of the charge transport substance shown below, 1 part by weight of a saturated polyester resin (manufactured by Toyobo Co., Ltd., Byron 200), and 1 part by weight of KP-323o and ooa similar to those in Example 1 were added to 20 to 50 parts by weight of tetrahydrofuran. Example 1
By a method similar to that described above, a composite type electrophotographic Fj & element assembly having charge transport material layers with different thicknesses was obtained. The characteristics were measured in the same manner as in Example 1, and the results are shown in Table 2.

Table 2 As shown above, as the thickness of the charge transport material layer increases, Vo and Vso/Vo improve, but conversely, E5G
indicates a sharp trend toward gold.

Example 3 η-type metal-free phthalocyanine (manufactured by Toyo Ink Co., Ltd.).

Average particle size φ0.5 x 1.5 μm 31 parts by weight, 0.5 to 5 parts of the same modified silicone resin as in Example 1, and 0.0 parts of the same methylphenylsiloxane compound as in Example 1.
The mixture was mixed in a ball mill for 5 hours to obtain a charge generating material layer in the same manner as in Example 1.

Next, 1 part by weight of the charge transport material shown below, 1 part by weight of the same saturated polyester resin as in Example 2, and 0.003 part by weight of the methylphenylsiloxane compound were dissolved in 25 parts by weight of tetrahydrofuran. Composite type electrophotographic photoreceptors having charge generating material layers having different thicknesses were obtained by the same method as above.

The characteristics were measured in the same manner as in Example 1, and the results are shown in Table 3.

Table 3 As shown, 5E50 tends to deteriorate as the amount of modified silicone resin in the charge generating material layer increases.

Example 4 η′ type metal phthalocyanine manufactured by Toyo Ink Co., Ltd.

Average particle size φ0.4 x 1.3 μma 1 part by weight, the same modified silicone resin type 1 sweet part as in Example 1, and 0.005 part by weight of a methylphenylsiloxane compound, all in tetrahydrofuran, 3 to 20% by weight in total solvent. The mixture was kneaded in a ball mill for 5 hours, and the thickness of the charge-generating substance layer was changed in the same manner as in Example 1.

Next, 1 part by weight of the charge transporting substance shown below, 1 part by weight of the same saturated polyester resin as in Example 2, 0.003 parts of a methylphenylsiloxane compound, and 25 parts by weight of total tetrahydrofuran were dissolved in the same solution as in Example 1. By this method, a composite electrophotographic photoreceptor was obtained. The characteristics were measured in the same manner as in Example 1, and the results are shown in Table 4.

Table 4 As shown, the thickness of the charge generating substance layer is preferably 3 μm or less.

Example 5 A2. of the composite type electrophotographic photoreceptor produced in Examples 1 to 4. A9. The spectral sensitivities of four types of samples, A14 and A20, were measured. The measurement was carried out using the same measurement system as in the above example, with a halogen lamp (60
0W) Spectroscopy was performed using a full spectrometer, and the sensitivity for each wavelength was completely reduced to zero.

The results are shown in the figure. As is clear from the above, the composite type electrophotographic photoreceptor of the present invention has good sensitivity even in the long wavelength region of 800 nm.

〔Effect of the invention〕

As described above, the composite type electrophotographic photoreceptor of the present invention has high sensitivity even in a long wavelength range, and is particularly suitable as a photoreceptor for a semiconductor laser printer using a semiconductor laser as a light source.

[Brief explanation of drawings]

The figure is a continuation of page 1 of the composite type electrophotographic photoreceptor according to the present invention. 0 Inventor: Itsuki Mori Hata @ Inventor: Tsuyoshi Narahara @ Inventor: Takano Pressure: 0 Inventor: Sawa 1) Manabu @ Inventor: Kumano Isao @ Inventor Enoki1) 3-1-1 Saiwai-cho, Hitachi City, Hitachi, Ltd. 3-1-1 Saiwai-cho, Hitachi, Hitachi, Ltd. Hitachi Research Laboratory, Hitachi, Ltd. 2-chome Kyobashi, Chuo-ku, Tokyo No. 3-13 Toyo Ink Manufacturing Co., Ltd. 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd. 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd. 2 Kyobashi, Chuo-ku, Tokyo No. 3-13 Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] 1. A composite electrophotographic photoreceptor in which a layer containing a charge generating substance and a charge transporting substance is provided on a conductive support, in which τ type, τ Kai, η Taki are used as the charge generating substance. , ij' type, and a compound represented by the following structural formula (A) as a charge transporting substance. R. (In the formula, %R1 and R2 represent an alkyl group, an aralkyl group, or an aryl group that may have a substituent group, and
tI'i represents an aromatic heterocyclic group which may have a substituent group. )