JPS6019153A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To form an electrophotographic sensitive body high in sensitivity to semiconductor laser beams by using specified deformed metal-free phthalocyanine as an electrostatic charge generating substance. CONSTITUTION:An electrophotographic sensitive body is obtained by laminating on a conductive substrate a <=about 20mum thick charge generating layer contg. (A) deformed eta-type metal-free phthalocyanine, obtained by milling an alpha-type metal-free phthalocyanine at about 50-180 deg.C, and/or a deformed eta-type metal- free phthalocyanine obtained by milling a mixture of alpha-type metal-free phthalocyanine and metal-free phthalocyanine having a substituent on its benzene ring at about 30-220 deg.C, and a 5-100mum thick charge transfer layer contg. (B) a charge transfer substance, preferably, a positive hole transfer type substance having an ionization potential of about 6.6eV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor suitable for laser beam printers and copying machines that utilize semiconductor laser light.

[Background of the invention]

Conventionally, many inorganic photoconductors including selenium (Se), cadmium sulfide (CdS), zinc oxide (ZnO), and polyvinylcarbazole (PVK) have been used.

Many organic photoconductors including perylene pigments and disazo pigments have been used as electrophotographic photoreceptors.

All of these have photosensitivity in the visible light range that matches the visual sensitivity, and are suitably used as photoreceptors for copying machines or gas laser printers. However, it has been difficult to use it because the sensitive wavelength range is not compatible with laser printers using semiconductor laser light sources, which are expected to have high reliability.

Gallium-aluminum-arsenide (Ga-At-As) light-emitting devices, which are currently widely used as semiconductor lasers, have an oscillation wavelength of about 750 nm or more, and cannot guarantee a long enough lifetime for practical use. Limited to 790 nm or more. Many studies have been made in the past in order to obtain high sensitivity to such long wavelength light.

For example, 5, e, and C, which have high sensitivity in the visible light region
It is possible to add a new sensitizer to materials such as dS to make the wavelength longer, but this method has not been put to practical use because it does not have sufficient environmental resistance to temperature and humidity, and is highly toxic. . The many types of organic photoconductive materials that are known are usually 7
Sensitivity is limited to the visible light region below QQnm, and there are few materials that exceed this range.

Among these, phthalocyanine compounds, which are one of the organic photoconductive materials, are known to have a photosensitive range extended to longer wavelengths than other compounds. An example of a phthalocyanine compound exhibiting photoconductivity is the X-type metal-free phthalocyanine described in Japanese Patent Publication No. 49-4338.

However, among the phase materials that have properties that can be used practically as electrophotographic photoreceptors, that is, in addition to photoconductivity, weather resistance, storage stability, mechanical strength, productivity, economic efficiency, etc.
A device with sufficiently high sensitivity beyond 90 nm is not to be overlooked. The present inventors focused on the characteristics of this phthalocyanine compound, attempted to improve it, and developed a new material that meets the purpose, thereby arriving at the present invention.

[Purpose of the invention]

An object of the present invention is to provide an electrophotographic photoreceptor that exhibits high sensitivity to semiconductor laser light.

[Summary of the invention]

The electrophotographic photoreceptor of the present invention is characterized in that it contains a modified τ type (τ' type) metal-free phthalocyanine and/or a modified η type (η' type) metal-free phthalocyanine.

The modified τ-type metal-free 7-talocyanine is defined as Salel. That is, for the xi of 1,541 people in CuKαVNi, the Bragg angle (2θ±0.2 degrees) is 7.5°9.1.
16.8.17.3, 20.3.20.8.21.4
It is a new metal-free phthalocyanine crystal polymorph having a strong X-ray diffraction pattern of 27.4 and 27.4. In particular, the infrared absorption spectrum is 75i±2c between 700 and 760 cm-'.
The four absorption bands where rn-1 is strongest are 1320 to 134.
There are two absorption bands of almost the same intensity between 0z-', 329
It is desirable to have a characteristic absorption at 7±3 crn-1.

The modified η-form metal phthalocyanine is defined as follows. That is, 100 parts by weight of metal-free phthalocyanine, and one or more of metal-free 7-thalocyanine having a substituent on the benzene nucleus, a 7-thalocyanine diisoisomer or metal 7-thalocyanine which may have a substituent on the benzene nucleus. A mixture with 50 parts by weight or less of a mixture of
The four absorption bands with the strongest cin-' are 1320 to 13
Two absorption bands of approximately the same strength between 40 crn-”,
It is a new metal-free 7-thalocyanine crystal polymorph having a characteristic absorption at 3297±5z-''.According to the study of the present inventors, η-type metal phthalocyanine has a particularly high Bragg angle (
2θ±0.2 degrees) is 7.5, 9.1, 16.8°1? ,
7.5.9 with an X-ray diffraction pattern showing strong peaks at 3, 20.3, 20.8, 21.4 and 27.4;
．． 1.16.8.17.3.20.3.20.8゜21
．． It is desirable to have an X-ray diffraction pattern showing strong peaks at 4, 22.1, 27.4 and 28.5.

In addition, both the modified τ-type metal-free phthalocyanine and the modified η-type metal phthalocyanine have a maximum value in the photosensitive wavelength range of 790 to 810.
in the nm range.

The modified τ-type metal-free phthalocyanine according to the present invention is produced in the following manner. That is, by milling α-type metal-free phthalocyanine at a temperature of 50 to 180 G, preferably 60 to 130 U with stirring or mechanical strain for a time sufficient to convert the crystal, metal-free phthalocyanine having a deformed τ dust crystal form is obtained. will be produced.

The α-type 7 talocyanine used in the present invention is the “7 talocyanine compound” by Moser and Torts (Mo5er
and Thomas “phthalocyanin”
Those obtained by known methods such as e(::pounds') and other suitable methods are used. For example, metal-free phthalocyanine is a metal phthalocyanine that can be demetalized with an acid such as sulfuric acid, such as lithium phthalocyanine.
Those produced by acid treatment of metal phthalocyanines containing cyanine, sodium phthalocyanine, calcium 7-thalocyanine, magnesium phthalocyanine, talocyanine, etc., or directly produced from 7-thalodinitrile, aminoiminoisoindolenine, or alkoxyiminoisoindolenine, etc. are used. It will be done. The metal-free 7-thalocyanine obtained by the already well-known method is preferably dissolved in sulfuric acid at 5C or less or made into a sulfate salt, and then poured into water or ice water and reprecipitated or hydrolyzed to obtain α-type metal-free Phthalocyanine is obtained.

At this time, if an inorganic pigment dissolved or dispersed in sulfuric acid or a reprecipitation solution is used, an α-metal-free 7-talocyanine containing an inorganic pigment can be obtained. This inorganic pigment may be any water-insoluble powder that can be used as a color filler, such as titanium white, zinc white, white carbon, calcium carbonate, etc.
Examples include metal powder, alumina, iron oxide powder, and kaolin.

α-type metal-free phthalocyanine containing this inorganic pigment is extremely easily ground during pigmentation compared to one that does not contain it.
It is easy to make into fine particles and is effective in saving labor and energy.

The α-type metal-free phthalocyanine subjected to such treatment is preferably used in a dry state, but a water-based form can also be used. 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, bicarbonate of soda, and vitreous 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 alcoholic solvents, such as glycerin, ethylene glycol,
1 from the group of diethylene glycol or polyethylene glycol solvents, cellosolve solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ketone solvents, ester ketone solvents, etc.
It is preferable to select more than one type.

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 180
G, preferably within a temperature range of 60 to 130C.

In addition, it is also effective to use a crystal nucleus as in a normal crystal transition process.

The α-type phthalocyanine used in producing the modified α-type metal-free phthalocyanine according to the present invention and the metal-free phthalocyanine having a substituent on the benzene nucleus, or a phthalocyanine nitrogen isoconstruct or metal having a substituent on the benzene nucleus The phthalocyanine is described by Moser and Torts [phthalosif = 7 compound J (Moser a
nd Thomas"phthalocyanine
The phthalocyanine nitrogen isoconstruct may include those obtained by known methods such as "Compounds") and other suitable methods.Furthermore, the phthalocyanine nitrogen isoconstruct may include one or more of the benzene nuclei of various porphines, such as phthalocyanine. Examples of metal phthalocyanines include copper tetrapyridinoporphyrazine in which 2 is replaced with a quinoline nucleus, and various metal phthalocyanines include copper, nickel, cobalt, zinc, tin, and aluminum.

Substituents include amino groups, nitro groups, alkyl groups, alkoxy groups, cyano groups, mercapto groups, halogen atoms, sulfonic acid groups, carboxylic acid groups or their metal salts, ammonium salts, and amine salts. can be exemplified as a relatively simple example. 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, USP No. 397398!, USP No. 40885)
(see Publication No. 07), 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 the α-type metal-free phthalocyanine and the metal-free phthalocyanine having a substituent on the benzene nucleus, or the phthalocyanine nitrogen isomer or metal-caped cyanine which may have a substituent on the benzene nucleus is 1001.
It may be 50 (weight ratio) or more, but preferably 10o
/aO~10010.1 (weight ratio). If the ratio exceeds this ratio, the obtained modified α-type phthalocyanine tends to bleed and its suitability as a pigment decreases.

In the present invention, mixing at the above-mentioned ratio may be done by simply mixing, or by mixing before acid pasting the α-type metal-free phthalocyanine. 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. A dispersion medium is not necessarily required, although a stone is an example.

The grinding auxiliary agent, the solvent used for crosstalk, the material used in the crystal transition step, and the equipment used are the same as those for the above-mentioned zero-band friend τ' type gold metal phthalocyanine.

The temperature range in the crystal transition step of the modified α-type metal-free phthalocyanine is 30 to 220 C, preferably 60 to 130 C.
The temperature should be within the temperature range of C. At very high temperatures, it is easy to transform to the β form, and at very low temperatures, it takes time to transform to the modified η form. It is also an effective method to use crystal nuclei as in the usual crystal transition process.

In the present invention, the above-mentioned modified τ plastic formation includes the combined use of other charge-generating substances in addition to the modified η type thermometallic phthalocyanide. Examples of such charge generating substances include α dust, β type, γ type, and τ type.

For η plasticization, metal-free phthalocyanine of Xm can be mentioned.

Of course, a combination of the modified τ-thermal metal phthalocyanine and the modified α-type metal-free phthalocyanine is also effective.

In addition, 7-thalocyanine pigments, azo pigments, and anthraquinone pigments other than those mentioned above are known as charge-generating substances.

indigoid pigments, quinacridone pigments, perylene pigments,
It is also effective to use it in combination with polycyclic quinone pigments, methine squaric acid pigments, etc. As an example of an azo pigment, (wherein, X is O
Indicates CH3 or Ct. Examples include disazo pigments and monoazo pigments such as ).

Here, the Bragg angle (26 ± 0.2 degrees) of the τ-type metal-free 7-thalocyanine is 7.6, 9.2, 16.8 degrees.
．． It is a metal-free phthalocyanine crystal polymorph having an X-ray diffraction pattern showing strong lines at 4, 20.4 and 20.9. The typical manufacturing method is to prepare α-type metal-free phthalocyanine from 50 to
It is characterized in that it is milled at 180C, preferably from 60 to 130C, with sufficient stirring or mechanical strain for a sufficient time to exhibit the τ type. In particular, the infrared absorption spectrum is 751±2 cm between 700 and 760 an-”
-” indicates the two absorption bands with almost the same strength, 328B±
It is desirable to have an absorption characteristic of 3crn-1.

The α-type metal-free phthalocyanine is not limited to pure metal-free 7-thalocyanine, but also includes a mixture with other 7-thalocyanines. The α-type metal-free phthalocyanine is composed of 100 parts by weight of α-type metal-free 7-thalocyanine and metal-free 7-thalocyanine having a substituent on the benzene nucleus, or a phtatetracyanine nitrogen isomer or metal which may have a substituent on the benzene nucleus. It is a mixture crystal of one type or a mixture of two or more 9 types of phthalocyanine and 50 parts by weight or less, and the infrared absorption spectrum is between 700 and 760 ctn-1.
The four absorption bands with the strongest c1n-' are 1320 to 13
It is a crystalline polymorph of metal-free phthalocyanine having two absorption bands of approximately the same intensity between 40 crn'''1 and a characteristic absorption at 3285±5 crn-'. ~220C, preferably 60-1
4. Milling at 30C with stirring or mechanical strain for a time sufficient to convert the crystal form to η type.
? There are signs. α-type metal-free phthalocyanine especially has a Bragg angle (2θ±0.2 degrees) of 7.6, 9.2, 16.8,
17.4 and 28.5, those with X# diffraction patterns showing peaks, and those with X# diffraction patterns showing strong peaks at 7.6°9.2, 16.8, 17
．． It is desirable to have an X-ray diffraction pattern showing strong peaks at 4, 21.5 and 27.5.

In the present invention, an electrophotographic photoreceptor is placed on a conductive support,
A layer comprising a charge-generating material and a charge-transporting material is provided, and the charge-generating material has the modified τ type and/or the charge-generating material.
Alternatively, it may contain a modified η natural metal phthalocyanine.

As the charge transport substance, photoconductive low molecules as shown below,
Photoconductive polymers, styryl dyes, and other materials containing dye 2 are used. Such a composite type electrophotographic photoreceptor is particularly one in which a layer made of a charge-generating substance is formed on a conductive support, and a layer made of a hole-transfer type charge-transporting substance is further formed thereon. Something is desirable. Since the carriers generated by ionized botensianin are caused by the low energy of long-wavelength light, conventional charge transport materials are inhibited by the energy shielding wall, making it difficult to obtain a highly sensitive photoreceptor for electrophotography. Therefore, by using a compound with p of 6.6 eV or less as a charge transport substance, low energy carriers can be transported smoothly and high sensitivity can be achieved.

The modified τ-type metal-free phthalocyanine exhibits maximum sensitivity between 790 and 810 Hm, and is therefore optimal as a photoreceptor for semiconductor lasers. Furthermore, the modified η-type metal 7 talocyanine has an extremely stable crystal plate, and is highly resistant to acetone, tetrahydrofuran,
Do not use organic solvents such as ethyl acetate or leave in air at 200C for more than 50 hours. This point is a great advantage in use during the production of electrophotographic photoreceptors.

An electrophotographic photoreceptor is formed by coating a mixed layer of deformed τ-thermal metal phthalocyanine and a binder resin on a conductive substrate such as aluminum. Binder resins include phenol resin, area resin, melamine resin, 7 run resin, epoxy resin, silicone resin, vinyl chloride-vinyl acetate copolymer, xylene resin, toluene resin, urethane resin, vinyl acetate-methacrylic copolymer. , acrylic resin, polycarbonate, cellulose derivatives, etc. are appropriately selected and used.

Furthermore, poly-N-vinylcarbasol exhibiting photoconductivity,
Carbazole terms such as Bo1J-9-P-vinylphenylanthracene, polymers having an anthracene ring in their side chains, other hetero terms such as pyrazoline terms, dibenzothiophene terms,
Polymers having aromatic groups in their side chains are also used as binders. Note that these photoconductive polymers can also be used as charge transport substances.

The mixing ratio of modified τ-type metal-free 7 thalocyanine and binder resin is 20 to 2 parts by weight of phthalocyanine per 100 parts by weight of resin.
00 parts by weight is appropriate, but if other sensitizers or charge transport materials are present, this can be reduced to about 1M parts. If the amount is less than 1 part by weight, no percentage sign of the modified τ-type metal-free phthalocyanine will appear in the sensitivity or sensitive wavelength range.

On the other hand, if it is 200 parts by weight or more, sufficient mechanical strength and dark charge retention ability cannot be ensured as a photoreceptor for electrophotography. The thickness of the mixed layer containing these modified τ-type metal-free 7-talocyanine is suitably 5 to 50 μm.

The photosensitivity of the electrophotographic photoreceptor according to one example of the present invention is determined by the photosensitivity when a special sensitizer or charge transport material is not used, that is, when a modified τ-type metal-free phthalocyanine is simply mixed into a general-purpose binder resin. In the case of the body, the half-exposure sensitivity (light energy required to halve the surface potential) for white light is 4
5 tuX·S (lux·seconds). At this time,
The semi-sensitive exposure amount for 800nm monochromatic light is 20mJ/m2
Extremely high sensitivity can be obtained as shown below.

Conventionally, 800. In a long wavelength region such as nm, the half-decreased exposure amount is usually more than xoomJ/m'', and it can be seen that the electrophotographic photoreceptor according to the present invention is very specifically adapted to a semiconductor laser.

The modified metal-free phthalocyanine used in the present invention is an inexpensive, non-polluting material that is easy to synthesize, and can be used in combination with a binder resin to form a flexible film or a drag etc. depending on the purpose. It can also be pointed out that it can be manufactured into various shapes and is extremely easy to handle as a photoreceptor for printers.

Incidentally, an electrophotographic photoreceptor using a modified η-type gold metal phthalocyanine is also manufactured by a similar method and exhibits similar characteristics.

By further forming a charge transport layer on the electrophotographic photoreceptor described above, a composite electrophotographic photoreceptor can be obtained. When quarrying such a laminated structure, the layer of deformed τ-type metal-free phthalocyanine (i.e. charge generation layer) is 0.1 μm thick.
It is possible to use it as a thin film to some extent. The charge transport layer may be formed below the charge generation layer containing the τ-type metal-free phthalocyanine (that is, between the conductive substrate and the charge generation layer).

As the charge transport material, the various photoconductive polymers shown in the previous section are used. Furthermore, oxazole derivatives, styryl dye pastes, cyanine dye bases, oxadiazole derivatives, pyrarizone derivatives, hydrazone compounds, poly-N-vinylcarbazole, triphenylmethane compounds, triphenylamine compounds, 2,4.7 -) dinitrofluorescein. It is also possible to form a charge transport layer by mixing known photoconductive low molecules such as nitrofluorenone such as nitrofluorenone into a general-purpose resin.

The charge transporting substance that can be used in the present invention includes at least one type of heterocyclic group of the general formula (where Z represents 0 or S,
The heterocyclic group may be substituted), and n is 0.
1 or 2, and R1 and R1 each represent an alkyl group having 3 or less carbon atoms. As a substituent for such a hetateradical group, -CH
lower alkyl groups such as a, CxHs, -C, R7, -
Ct.

-13r, etc., 7N(CHa)i, N(C2H
5) Examples include, but are not limited to, dialkylamino groups such as 2, N (Cs R7) z, and phenyl groups.

Specific examples of such compounds are listed below based on their structural formulas.

(CHshN Other typical examples of oxazole derivatives include. Examples of styryl dye pastes are detailed in the next section. Examples of cyanine dye bases include 2H5. Oxadiazole derivatives include, for example. Examples of pyrazoline derivatives include 2H5. Examples of hydrazone derivatives include 2H5. Examples of triphenylmethane compounds include N(CzHsh CHs).

By adopting a composite type photoreceptor structure in which charge transport layers are laminated in this way, the white light half-exposure amount is 1 to 2 tux-
The monochromatic light half-life exposure amount can reach 10 mJ/m2 or less.

A composite electrophotographic photoreceptor using a charge generation layer containing a liquid η-type metal 7-talocyanine can also be produced by a similar manufacturing method and exhibits similar characteristics.

In order to produce the electrophotographic photoreceptor of the present invention as a composite type, a layer of a charge-generating substance is formed on a conductive support, and a layer of a charge-transporting substance is further formed thereon. Alternatively, a layer of charge generating material may be formed on a layer of charge transporting material.

The method for forming the charge-generating substance layer is to disperse the deformed τ-type gold metal phthalocyanine alone or in a mixture with a binder resin into fine particles (particle size of 5 μm or less, especially 1 μm or less) using a ball mill or roll mill, or to form a mixed metal phthalocyanine. The mixing ratio of the metal phthalocyanine and the binder resin varies, but it is usually 20 μm or less, particularly preferably 0.1 to 3 μm, so that the thickness does not deteriorate as the film thickness increases, and the film does not have flexibility. If peeling occurs. Further, the blending ratio of the modified τ-type metal-free phthalocyanine and the binder resin is preferably 1 part by weight of the former to 5 parts by weight or less of the latter, and if it exceeds this, the sensitivity tends to gradually decrease.

The formation of a layer of charge transport material is also carried out by coating.

A binder resin is required in the layer of the charge transport material in order 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 containing both the charge transport substance and the binder resin is used as a coating liquid. The thickness of the charge transport material layer is determined by the charging characteristics required for the photoreceptor, but is usually 5 to 100 μm, preferably 8 to 100 μm.
A suitable thickness is 30 μm. The blending ratio of the charge transport substance and the binder resin is 1 part by weight of the former and 0.0 parts by weight of the latter.
A suitable range is 5 to 5 parts by weight.

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

Toluene resin, urethane resin, vinyl acetate-methacrylic copolymer, acrylic resin, polycarbonate resin, polyester resin, cellulose derivative, etc. are appropriately selected and used. Furthermore, bov-N-vinylcarbasol, bo!, which exhibits photoconductivity, is also available. j-9-(P-vinylphenyl)anthracene and other carbazole groups, polymers with anthracene terms in their side chains, other hetero terms such as pyrazoline groups, dipenzothiophene terms, and aromatic terms in their side chains. Polymers are also utilized as binder resins.

In the present invention, a surfactant or a warming agent may be added to the charge generating substance layer and the charge transporting substance layer as necessary, and the addition of these agents will improve the properties of the charge generation substance layer and the charge transport substance layer, as well as adhesion and abrasion resistance. Mechanical properties such as, film formability.

Electrophotographic properties can be improved by improving physical properties such as flexibility and material dispersibility.

Conductive 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, copper iodide, indium oxide or tin oxide. It is generally desirable that the support be itself conductive or have a conductive surface and be strong enough to handle.

[Embodiments of the invention]

The present invention will be explained in detail below. In the description of each example, all parts mean parts by weight.

Example 1 10 parts of α-type metal-free 7-thalocyanine, 200 parts of common salt as a grinding aid, and 300 parts of ethylene glycol as a dispersion medium were placed in a sand mill and kneaded at 100 t:' for 20 hours.

After confirming the transition to the modified τ type using an X-ray diffraction diagram, the container was taken out and the grinding aid and dispersion medium were removed with water and methanol. After that, it is purified with dilute sulfuric acid aqueous solution, filtered,
After washing with water and drying, clear greenish blue crystals were obtained. This crystal was confirmed by X-ray diffraction and infrared spectroscopy to be a modified τ-type metal-free phthalocyanine.

4 parts of this modified τ-type metal-free phthalocyanine, acrylic resin (manufactured by Toyo Ink Manufacturing Co., Ltd., T C0at) (-031
2) 18 parts, acrylic resin (manufactured by Toyo Ink Manufacturing Co., Ltd.,
After kneading 18 parts of T-Coat PFX-9004), 7 parts of methyl ethyl ketone, and 8 parts of toluene in a porcelain ball mill for 48 hours, it was rolled onto a 100 μm thick aluminum plate so that the coating thickness was 6 to 7 μm. coat,
Dry at 130c for 60 minutes.

It was dried and used as an electrophotographic photoreceptor.

The composite type electrophotographic photoreceptor constructed as shown in this example is an electrostatic recording paper tester (manufactured by Kawaguchi Electric Co., Ltd., 5P-42).
8) was used to evaluate the electrophotographic properties. In this case, charge by performing corona discharge of positive or negative 5 kV for 10 seconds (the surface potential Vo(v) immediately after charging for 10 seconds is taken as the initial potential), and leave it in a dark place for 30 seconds (at this time, the potential tv
Expressed as so(v), (V, go/Vo) xl 00
(H) is the dark attenuation), the surface is exposed with a tungsten lamp so that the illumination intensity is 2 Lux, and the surface at this time is
The attenuation of the potential and the time were recorded, and the white light sensitivity (half exposure amount, Ego (tux-s)) was expressed as the product of the time t (seconds) required for VlIO to decrease to 1/2 and the illuminance. Spectral sensitivity is determined by using each wavelength from a spectrometer as a light source instead of a tungsten lamp, and measuring the time t (seconds) required for V2O to become 1/2 and the energy of each wavelength (mW/m
The reciprocal of the product with 2) was defined as the sensitivity (m''/mJ).

The electrophotographic photoreceptor of this example has a positive 5. Under charging conditions of Ok V, (1) initial potential Vo = 750■, (2) dark decay rate Vso/Vo = 7596, (3) half-reduced exposure amount E
A value of 50 = 3.5 Lux·sec was obtained, indicating extremely high sensitivity. Furthermore, when we set the half-reduced exposure amount E: 8° for the light split into 8QQHm, we found that it was 12
It was found that it is highly sensitive to light with a long wavelength of mJ/m2.

Example 2 1 part of modified τ-type metal 7 talocyanine produced in the same manner as in Example 1, silicone resin (manufactured by Shin-Etsu Silicone, K-52)
40, non-volatile content 15%) and 35 parts of tetrahydrofuran were milled in a magnetic ball mill, and the coating liquid was mixed with lOθ
Deep coated on a μm thick aluminum plate) L, 90C
, and was cured for 20 minutes to form a charge generation layer. The dry thickness of the charge generation layer was 1 μm. Next, using 1 part of the charge transport substance shown in Table 1, 3 parts of the binder resin, and 1 part of tetrahydrofuran or dichloromethane (lk mixed and fc coating liquid,
A charge transport layer was formed by dip coating on the charge generation layer and drying at 90C for 11 hours.

The total film thickness including both layers was the value shown in Table 1.

The electrophotographic properties of these electrophotographic photoreceptors were evaluated in the same manner as in Example 1. The results are shown in Table 2.

The half-reduction exposure amount Ego is 3 tux・sec or less, and 8
It was found that E::0 at 00 part m exhibits a high sensitivity of 12 mJ/m'' or less.

Example 3 Purified α-type metal-free phthalocyanine 10 (1,7-72y derivative P c +C0NHxNHCsHn) 1
．． 3 (However, Pc indicates a phthalocyanine nucleus, and the number in parentheses is
The number 1 indicates the average number of substitutions from the analysis. ) 15 parts:
200 parts of ground common salt and 80 parts of polyethylene glycol were placed in a kneader and ground at 100 m for 8 hours. After taking it out, it was purified with a 2% dilute aqueous sulfuric acid solution, filtered, washed with water, and dried to obtain modified η-type metal phthalocyanine 2.

Next, 1 part of this modified η-type gold metal phthalocyanine, 1 part of phthyral resin (XYHL manufactured by Union Carby),
and 20.30 or 40 parts of Kishio, respectively, were kneaded in a ball mill for 5 hours to prepare a coating liquid.

This coating liquid was applied with an applicator onto a 1100A aluminum plate and dried for 1 hour to form a charge generation layer. In case O,
In the case of Sμm1 and 40 parts of xylene, it was 0.2 μm.

Next, 1 part of the following oxazole compound, 3 parts of polycarbonate (manufactured by General Electric Company, Lexan 141)
A mixed solution of 16 parts of dichloromethane and 16 parts of dichloromethane was coated on the charge generation layer and dried to prepare an electrophotographic photoreceptor.

The film thickness after drying was about 20 μm.

Electrophotographic properties were measured in the same manner as in Example 1. The results are shown in Table 3.

As the thickness of the charge generation layer decreases, the initial potential VOs dark decay Vsa/V6 improves. In either case 3tux
- It is clear that the sensor has high sensitivity with a half-reduced exposure amount of less than a second (ESO).

〔Effect of the invention〕

As explained above, according to the present invention, an electrophotographic photoreceptor that is highly sensitive to semiconductor laser light can be obtained. Toyo Ink Manufacturing Co., Ltd., 2-3-13 Kyobashi, Chuo-ku, Tokyo Inventor: Isao Kumano, Toyo Ink Manufacturing Co., Ltd., 2-3-13 Kyobashi, Chuo-ku, Tokyo Applicant: Toyo Ink Manufacturing Co., Ltd. 2-3-13 Kyobashi, Chuo-ku, Tokyo

Claims (1)

[Claims] 1. An electrophotographic photoreceptor characterized by containing modified τ-type metal-free 7-talocyanino and/or modified η-type gold-metal 7-talocyanine.