JPS63155051A - Electrophotographic positive charge sensitive body and image forming process thereof - Google Patents

Abstract

PURPOSE:To permit provision of good UV resistance, high sensitivity and high durability to an electrophotographic sensitive body having layers contg. an electric charge generating material CGM and charge transfer material CTM by incorporating a specific compd. into said body. CONSTITUTION:This electrophotographic sensitive body which has the layers contg. the charge transfer material and charge generating material on a conductive base is the electrophotographic positive charge sensitive body contg. the compd. expressed by the formula. In the formula, A denotes an oxygen, sulfur atom or imino group. R1 denotes an aryl group, allyl group, R denotes alkyl, amino, nitro and alkoxy substituting groups which substitute hydrogen or halogen atom, n is 0 or 1, 2. The amt. of the compd. to be added is 0.1-100wt%, more preferably 1-50wt%, more particularly preferably 5-25wt% by the weight of the charge transfer material (CTM) in the charge generating layer (CGL) when said compd. is used in CGL. Said amt. is 0.1-100wt%, more preferably 1-50wt% by the weight of the binder resin in a protective layer (OCL) when the compd. is used in OCL.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and particularly to a positively charging photoreceptor.

[Conventional technology]

Conventionally, for example, as an electrophotographic photoreceptor, senone, oxidation 1!1! Azure photoreceptors are widely used in which the photoreceptor layer contains an inorganic photoconductive substance such as lead or cadmium sulfide.

On the other hand, in recent years, active research and development has been conducted on the use of various photoconductive substances as materials for photoreceptor layers of electrophotographic photoreceptors.

For example, Japanese Patent Publication No. 10496/1983 describes an organic photoreceptor having a photoreceptor layer containing poly-N-vinylcarbazole and 2,4,7-dolinite (1-9-fluorononone). This photoreceptor is not necessarily satisfactory in terms of sensitivity and durability.In order to improve these shortcomings, the charge generation function and the charge transport function are assigned to different materials in the photoreceptor layer. Many attempts have been made to develop organic photoreceptors with high sensitivity and durability.

In such so-called function-separated type electrophotographic photoreceptors, it is possible to select substances that exhibit each function from a wide range of materials, so it is relatively easy to produce electrophotographic photoreceptors with arbitrary characteristics. It is possible to cheat.

A large number of materials have been proposed as effective charge generation layers for such functionally separated electrophotographic photoreceptors. Examples of using inorganic substances include Japanese Patent Publication No. 43-161
There are amorphous cells, which are combined with organic charge transport materials, as described in 98.

In addition, many electrophotographic photoreceptors using organic dyes or organic pigments as a charge generation layer have been proposed. -37543, 55-22834, 5
It is already known from No. 479632, No. 56-116040, etc. Note: These organic photoconductive materials are usually used in negatively charged photoreceptors, and the reason for this is that when negatively charged, the mobility of the poles among the charges is large, so the photosensitivity etc. This is because it is advantageous in terms of However, when using such negative charging, there is a problem that ozone is likely to be generated in the atmosphere during negative charging by the charger, which worsens the environmental conditions. Still another problem is that positive polarity toner is required for development of negatively charged photoreceptors, but positive polarity toner is difficult to manufacture in view of the triboelectric charging sequence with respect to ferromagnetic charged particles.

Therefore, it has been proposed to use a positively charged photoreceptor using a photoconductive material. For example.

When forming a photoreceptor by laminating a charge transport layer on a charge generation layer, in order to efficiently cancel the positive charge on the surface of the photoreceptor, the charge transport layer is coated with a compound having a large electron transport ability, such as trinitrofluoro etc., but these substances are carcinogenic and are classified as 4! l! Hygiene 1 - There are problems such as being extremely inappropriate.

Furthermore, as a positively charged photoreceptor, U.S. Patent No. 3,615,41
No. 4 shows No. 6 containing thiapyrylium salt (charge generating function) so as to form a eutectic complex with polycarbonate (bi:noda resin). However, this known photoreceptor has the drawbacks of a large memory phenomenon and a tendency to generate ghosts. Also US Patent No. 3,357,989
No. 1 also shows a photoreceptor containing phthalocyanine, but the properties of phthalocyanine change depending on the active type.''Secondly, there is the difficulty of having to strictly control the crystal type, and the memory phenomenon. is large and has low short wavelength sensitivity, making it unsuitable for copying machines whose light source is visible light including the short wavelengths.

As described above, various attempts have been made to obtain positively charged photoreceptors, but all of them have many problems that need to be improved in terms of photosensitivity, memory phenomenon, labor hygiene, etc.

Therefore, a charge-generating layer that generates holes and electrons when irradiated with light and a charge-generating layer containing a charge-generating layer are made into two layers (surface layer), a charge-transporting layer containing a charge-transporting material having a hole-transporting function is a lower layer, and a charge-generating layer containing a charge-transporting substance having a hole-transporting function is a lower layer. It is possible to use a photoreceptor having a photoreceptor layer for positive charging. Furthermore, it is conceivable that a photoreceptor having a single-layered photoreceptor layer including the charge generation layer and the charge transport function can be used for positive charging.

In addition, in such a photoreceptor for positive charging, if a charge generation layer having electron-attracting property (2) is used in the structure, the movement of electrons to cancel the positive charge on the surface of the photoreceptor can be prevented. It is conceivable that it will be faster and that high sensitivity characteristics can be obtained.

however,! In all of the positive charging photoreceptors described in 1q, a layer containing a charge generation layer is formed as a surface layer, so they are vulnerable to external effects such as light irradiation, especially short wave light irradiation such as ultraviolet rays, corona discharge, humidity, and mechanical friction. As a result, the electrophotographic performance deteriorates during the storage of the photoreceptor and during the image formation process, resulting in a decrease in image quality.

In a negative charging photoreceptor having a conventional charge transport layer as a surface layer, the influence of the above six types of external effects is extremely small. ) The charge transport layer has the function of protecting the underlying charge generation layer.

Therefore, it is conceivable to provide a thin protective layer made of an insulating and transparent resin to protect the charge generation layer and the layer containing the charge generation layer from external effects, but the charge generated during light irradiation is blocked by the protective layer. and the light irradiation effect is lost (
Also, if the protective layer that forms the surface layer has large patterns, it will cause a decrease in sensitivity and will have little UV blocking effect. cannot be entrusted to.

[Purpose of the invention]

The object of the present invention is to have a positively charging photoreceptor layer comprising a charge generation layer (denoted as CGM) and a charge transport material (denoted as CTM), and to provide high sensitivity and durability with good UV resistance. The purpose is to provide a positively charged electrophotographic photoreceptor.

[Structure and effects of the invention]

[1] According to the present invention described above, C1゛M is formed on a conductive support.
This is achieved by an electrophotographic positively charged photoreceptor having a layer containing CGM and CGM, which is characterized by containing a compound represented by the following general formula.

In the general formula, A does not represent oxygen, a sulfur atom or an imino group. It
+ represents an aryl group or an allyl group, and the aryl group or allyl group may be substituted with a hydrogen alkyl, amino, nido, alkoxy substituent or halogen atom. represents.

n is O or 1.2, and when n=2, R may be the same or different.

The photoreceptor layer provided on the conductive support according to the present invention is CT
It may have a single-layer structure in which M and CGM are mixed, or it may have a multi-layer structure in which a layer containing CTM is a lower layer and a layer containing CGM is an upper layer. Further, a protective layer (marked as OCL) may be provided as necessary.

The compound according to the present invention is added to at least one of the above layers, but is preferably added to the surface layer of the photoreceptor layer. In addition, it may be in a form where it is most concentrated on the surface layer and gradually decreases toward the inside.

The present invention will be explained in detail below.

In the electrophotographic process based on the Carlson process, a light source that generates ultraviolet rays is generally used for image exposure, erasing exposure, pre-transfer exposure, cleaning exposure, etc. Repeated irradiation with energetic ultraviolet light is sufficient to cleave the organic compound molecules used in the photoreceptor. That is, C forming the photoreceptor
GM, CTM, binders, etc. cause radical dissociation, lose their original molecular structure, and deteriorate, resulting in deterioration of the photoreceptor. Specifically, they cause a decrease in sensitivity, an increase in residual potential, etc., and cause fogging. occurs, resulting in a decline in image quality.

As described in the prior art, in a positively charging photoreceptor using an organic photoconductive substance, a charge generation layer (hereinafter referred to as ca
Since the layer (marked as t) becomes the surface layer, it lacks scratch resistance, and in order to improve durability -1-, it is necessary to increase the CGLEI thickness. However, reducing the pattern causes a decrease in sensitivity. CG as a means to suppress this decrease in sensitivity! It is effective to add a charge transport material (CTM) to the layer, but since this CTM has a structure that is more susceptible to ultraviolet oxidation than the charge generation layer (CGM), it is easily degraded by ultraviolet rays and becomes photosensitive. The durability of the body is impaired.

As a result of extensive research into improving the prevention of ultraviolet deterioration of photoreceptors, the inventors of the present invention have found that a compound in which a five-membered hetero ring and an aromatic ring are combined can be included in CGL, which is the surface layer of a positively charged photoreceptor. It has been found that the above deterioration can be significantly reduced by this.

The stabilization mechanism of the a-search compound in the above-mentioned compound, that is, the ultraviolet absorber, is thought to be due to the stored decomposition energy of ultraviolet rays (sometimes referred to as UV) becoming the energy of U absorption and absorption circular vibration. .

The energy of this vibration is released from the UV absorber as thermal energy, but the thermal energy is already insufficient to degrade the organic compounds and is thought to protect the photoreceptor from the harm of repeated UV irradiation. It will be done.

Next, specific compounds represented by the above general formula are illustrated.

-ゝ, No, A R+
11nWhen used in OCL, the amount of the compound of the present invention added is 0.1 to 100% by weight, preferably 1 to 50% by weight, particularly preferably 5 to 50% by weight, based on C'1'M in CG L. 25% weight. In addition, when used in OCL, 0.0% relative to the binder resin in OCL.
It is 1 to 100% by weight, preferably 1 to 50% by weight.

Next, the structure of the photoreceptor of the present invention will be explained with reference to the drawings. As a photoreceptor, for example, as shown in FIG. 1, there is a support! (A conductive layer provided on a conductive support or sheet) A charge transport layer (labeled as CTL) 2 containing C'I''M and a binder resin as necessary is the lower layer, CGM, C
Contains TM and binder resin if necessary c c
L, 3 is provided as an upper layer and a photoreceptor layer 4 of a zigzag laminated structure, as shown in FIG. 2, a protective layer (OCL) 4 is provided on the photoreceptor layer of FIG. 1, and as shown in FIG. As shown in Fig. 3, a photosensitive layer 4 having an intermediate layer structure containing CGM, CTM, and a binder resin as necessary is provided on a support, etc.; An OCL may be provided between the support and the photoreceptor layer, and an intermediate layer may be provided between the support and the photoreceptor layer.

Next, as the CGM suitable for the present invention, both inorganic pigments and organic pigments can be used as long as they absorb visible light and generate free charges. Amorphous se1non,
Trigonal selenone, selenone-arsenic alloy, selenium-non-tellurium alloy, cadmium sulfide.

In addition to inorganic pigments such as cadmium selenide, cadmium selenide sulfate, mercury sulfide, lead oxide, and lead sulfide, organic pigments such as those shown in the following representative examples may be used.

(1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo and thiazole azo pigments.

(2) Perilone pigments such as perilone acid anhydride and perylenic acid imide.

(3) Anthraquinone or polycyclic quinone pigments such as anthraquinone derivatives, anthanthrone derivatives, dibenzpyronequinone derivatives, vilantrone derivatives, biolant derivatives and isoviolanthrone derivatives (4) Indigoids such as indigo derivatives and thioindigo derivatives (5) Phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine (6) Carbonium pigments such as diphenylmethane pigment, triphenylmethane pigment, quinanthene pigment, and acridine pigment (7) Azine pigment, oxazine pigment, thiazine pigment, etc. Noki, nonimine pigments (8) Methine pigments such as cyanine pigments and azomethine pigments (9) Quinoline pigments (10) Nitro pigments (11) Nido pigments (12) Benzoquinone and naphthoquinone pigments (13) )
Naphthalimide pigments (4) Perinone pigments such as bisbenzimidazole derivatives Examples of azo pigments used in the invention include those shown in the following exemplary structural compound groups [I] to CV). If so, list some examples of specific preferred compounds in the group of exemplified structural compounds.

For the complete details of the preferred specific compounds, please refer to Patent Application No. 61-195881.Exemplary Structural Compound Group [I]: Exemplary Structural Compound Group [■]: Exemplary Structural Compound Group [■]: Exemplary Structure Compound group [■]: Okaji structural compound group [■]: In addition, the following exemplary structural compound groups (Vl) to [■] consisting of polycyclic quinone pigments are most preferred as CGMs. Exemplary structural compound group [■]: , /"C'I" M usable in the present invention is not particularly limited, but includes, for example, oxazole derivatives, oxadiazole derivatives, and thiazole derivatives. , thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidasilone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, oxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives,
These may include benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.

However, in addition to having an excellent ability to transport the poles generated during light irradiation to the support side, those suitable for combination with the above-mentioned CGM are preferably used, and examples of such C 'I' M include the following exemplified compound +1. group (IK) or (
A still compound represented by X) is used. Some specific examples of individual compounds in the group of exemplified structural compounds are listed below, but please refer to Japanese Patent Application No. 61-195H1 for the complete details.

Exemplary structural compound group (IK): Exemplary structural compound group (X) In addition, the following exemplary structural compound group [β] to (X
Hydrazone compounds represented by V) can also be used. For the complete details of the specific compounds on the opposite side, please refer to the patent application 1976-19.
Reference is made to No. 5881.

Exemplary structural compound group [■] Exemplary structural compound group (XVI): In addition, as CTM, the following exemplary structural compound IIT, (X
Amine derivatives shown in (2) can also be used.

For details, refer to Japanese Patent Application No. 195881/1981.

Next, as a binder that may be used in the QC+ of the present invention, the volume resistance tPΩcI! ! -1-1 Preferably 10I0
A transparent resin with an ΩC life value of 1-1 or more preferably 1011 Ωcfi or more is used. ii; The binder described in i. contains at least 50% by weight of a resin that hardens under light or heat.
Examples of such resins that harden with light or heat include thermosetting acrylic resins, silicone resins, epoxy resins, resins, urea resins, phenolic resins, and polyesters. There are resins, alkyd resins, melamine resins, photocurable cinnamic acid resins, etc., or co-1R combinations or co-condensation resins of these.In addition, all thermosetting resins can be used for electrophotographic materials. reactor. In addition, if necessary, less than 50% by weight of a thermoplastic resin can be contained in the above-mentioned oct for the purpose of improving workability and physical properties (preventing cracks, imparting flexibility, etc.). Such thermal 6I plastic resins include, for example, borine, acrylic resins, methacrylic resins, vinyl chloride resins, vinyl acetate resins, epoxy resins, butyral resins, polycarbonate resins, silicone resins, or copolymers thereof. Resins, such as vinyl chloride-vinyl acetate ζ-R composite resin, vinyl chloride-vinyl acetate-anhydride polymer (twin acid copolymer resin), polymeric organic semiconductors such as poly-N-vinylcarbazole, and other electrophotographic materials. In addition, the OC!7 may contain an electron-accepting substance, and may also contain an ozone antioxidant or the like for the purpose of protecting CGM if necessary. , dissolved in a solvent together with the binder, applied by dip coating, streak-free coating, blade coating, roll coating, etc., and dried to give a 2μ
The layer thickness is preferably 1 μm or less.

The layer structure of the photoreceptor layer of the present invention has a laminated structure and an intermediate layer structure as described above, but C'rL, CCL, or OCt has a high sensitivity.2.Reduction of residual potential or fatigue during repeated use. etc. [1 type, 1 type or 2! ,! ! It is possible to contain the electron-accepting substance described in 1- below.

Examples of electron-accepting substances that can be used in the present invention include 1-succinic anhydride, maleic anhydride, dibro-12 maltsonic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromo phthalic anhydride, 3-nido “?Phthalic anhydride,
4-Nitro-phthalic anhydride, vinyl anhydride (1-mellitic acid, mellitic anhydride, tetracyanoedilone, te!-lacyanoquinodimethane, 0-dinitrobeninozene, pharynginide)
7 Benzene, 1, 3, 5. - trinide [l benzene,
Varanitrobenzonitrile, picryl chloride, quinoninochlorimide, chloranil, brumanil, 2-methylnaphthoki, non, dichlorodicyanovarbenzoquinone, anthraquinone, dinitroquinone, trinide, fluorozonone, 9-fluorononylidene [dicyanomethy 1 nonmalonodinitrile], polynitro-9-
Examples include fluoro[nonylidene][dicyanomethylene malonodinitrile], picric acid, and phthalic acid.

Examples of binder resins that can be used in the photoreceptor layer in the present invention include polyethylnon, borine [! Addition polymerization of pyrinone, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, poly: [ster resin, alkybutane resin, polycarbonate resin, silicone resin, melamine resin, etc.] type resins, 8F addition type resins, IE condensation type resins, and copolymer resins containing two or more of these resins, such as vinyl chloride-vinyl acetate co-1F polymer resins, vinyl chloride-vinyl acetate copolymer resins, In addition to insulating resins such as vinyl acetate-maleic anhydride copolymer resins, polymeric organic semiconductors such as poly-N-vinylcarbazole may be mentioned.

Next, the conductive support supporting the photoreceptor layer may be a metal plate made of aluminum or nickel, a metal drum or metal foil, a plastic film coated with aluminum, tin oxide, indium oxide, etc., or a conductive material coated thereon. Paper, film such as Plus Deck, or drums can be used.

CTL is prepared by dissolving or dispersing the above-mentioned CI'M in a suitable solvent together with a central pillar or a suitable binder resin and drying it.8 The solvent used to form C'rL is as follows: For example, N
, N-dimethylformamide, benzene, toluene, xylene, monochlorobenzene, ■, 2-dichloroethane, dichloromethane, 1,1,2-trichloroethane, tetrahydrofuran, methyl ethyl ketone, ethyl acetate,
Butyl acetate and the like can be mentioned.

When the photoreceptor layer according to the present invention is formed with a multilayer structure of CGL and CTL, the thickness of CTL is preferably 5 to 50 μm.
m1 is particularly preferably 5 to 30 μm.

CTM is 20 to 200 parts by weight, preferably 30 to 150 parts by weight, per 100 parts by weight of binder resin in C1''L.

If the CTM content is less than this, the photosensitivity will be poor and the residual potential will tend to be high, and if it is more than this, the solvent solubility will be poor.

CGL can be used by combining the CGM and CTM described above separately or by -
First, apply it alone or dissolve or disperse it together with a suitable binder resin in a suitable solvent, and dry it to form C'
It can be formed in the same manner as in the case of 1'L.

When CCL is formed by dispersing the above CGM, it is preferable that the CGM has an average particle size of 2 μm or less, preferably 1 μm or less. That is, if the particle size is too large, dispersion in the layer will be poor, and some of the particles will protrude from the surface, resulting in poor surface smoothness. In some cases, discharge may occur at the protruding parts of the particles, or toner may Particles tend to adhere and toner filming phenomenon occurs easily.

However, if the above particle size is too small, it tends to aggregate,
It is desirable that the lower limit of the average grain size be 0.01 μm wide because the resistance of the layer increases, the sensitivity and repeatability decrease due to the increase of crystal defects, or there is a limit to miniaturization.

CGL can be provided by the following method.

That is, the CGM described above is made into fine particles in a dispersion medium using a ball mill, homomixer, etc., and then mixed with a binder resin and CT.
This is a method of applying a dispersion obtained by adding M and mixing and dispersing it. When the particles are dispersed under the action of ultrasound in this method, uniform dispersion is possible.

CGM per 100 weight of binder resin in CCL is 20~
200 mm parts, preferably 25 to 100 parts by weight,
Ci'M Mo (20 to 200 parts by weight, preferably Ha3
0-150tli ff1 part.

If the amount of CGM is less than this, the photosensitivity will be low and the residual potential will increase, and if it is more than this, the dark decay will increase and the acceptance potential will decrease.

The thickness of the CGL formed as described above is preferably 1 to 10 μm, particularly preferably 2 to 7 μm.

In the case of a laminated structure, the film thickness ratio of CGL and CTL is 1; (1 to
30) is preferable.

Next, when the photoreceptor of the present invention is composed of a single layer, the proportion of CCM contained in the binder resin is 20 to 200 parts by weight, preferably 25 to 1 part by weight, based on 100 parts by weight of the binder resin.
00 parts by weight.

If the content of CGM is less than this, the photosensitivity will be low and the residual potential will increase, and if it is more than this, dark decay and acceptance potential will decrease.

Next, the content ratio of C'l'M to the binder resin is 20 to 200 parts by weight per 100 parts by weight of the binder resin.
The amount is 1 part by weight, preferably 30 to 150 parts by weight.

If the CTM content is less than this, the photosensitivity will be poor and the residual potential will tend to be high, and if it is more than this, the solvent solubility will be poor.

The weight ratio of CTM to CGM in the single-layer photoreceptor layer is preferably 1:3 to 1:2.

The thickness of the single-layer photoreceptor layer is 7 to 50 μm, and more preferably 10 to 30 μm.

Further, the intermediate layer functions as an adhesive layer or a barrier layer, and in addition to the binder resin, for example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-anhydrous Maleic acid copolymer, casein, N
-Alkoxymethylated nylon, starch, etc. are used.

Next, an image forming process using the positively charged photoreceptor of the present invention will be explained with reference to FIG.

FIG. 4 shows an image forming block 1 of the present invention surrounding a photoreceptor drum of the present invention which carries a toner image following an electrostatic latent image. An example of the arrangement of various functions related to access and IB materials is shown.

The positively charged photoreceptor 20 of the present invention is grounded by a conductive support, and is rectified to give a positive charge. Positively charged and clockwise (direction A in the diagram)
Rotate to .

Also, the reflected light E from the original on the original placing table is reflected by the mirror 1.
The photoreceptor 20 (Drano, etc.) passes through an optical system consisting of nons, etc.
” is inputted through the slit S.

Since the photoreceptor drum 20 is charged in advance by the charger 21, electrostatic latent images corresponding to the original are sequentially formed on the photoreceptor drum 20 according to the incidence of light from the optical system, and the rotating photoreceptor The electrostatic latent image on the body drum 20'' is turned into a visible toner image by the developing device 22.

On the other hand, the transfer paper is fed out from the paper feeder, guided up the guide plate, and reaches the paper feed [1-ra 32, photoreceptor drum,
Feed the paper in accordance with the timing signal so that the leading edge of the toner image marked 11 on 20 and the leading edge of the transfer paper do not match.

Thereafter, the toner image on the photosensitive drum 20 is transferred to a transfer paper by the action of the transfer pole 23. and separation pole 24
The transfer paper separated from the photoreceptor drum 20-t is sent to the fixing device via the transfer paper conveyance means 35, and is fixed by heat fixing "ν-ra" and pressure "F[7-ra". After that, the paper is ejected onto a paper ejection tray by a paper ejection roller.

On the other hand, after the transfer process is completed, the drum surface of the photoreceptor drum 20 is electrically cleaned by a cleaning removal electrode 25 that performs AC corona discharge in order to facilitate the removal of residual toner on the drum by the cleaning device 26. The toner remaining on the drum without being completely transferred is then scraped off by a cleaning device 26 such as a blade.

This will prepare the drum for the next copy.

The above is Hanawamoto's process for copying, but in order to improve the image quality, copying machines use a process called pre-exposure. The first pre-exposure device 27 is the cleaning device 26
and the charger 21, and consists of a light source such as a fluorescent light. The photosensitive drum 20 from which toner has been removed from the surface by the cleaning device 26 is subjected to cleaning exposure by the pre-exposure device 27 to remove residual charges on the drum surface and the potential becomes zero.

The second 1fj exposure device 28 includes a developing device 22 and a transfer pole 23.
, the separation electrode 24, and the third pre-exposure device 29 is disposed at a position behind the separation electrode and other separation parts and in the flow direction of the cleaning and removal electrode 25, and is equipped with a light source such as a fluorescent light. Consists of etc. Light irradiation by the second and third pre-exposure devices,
That is, by the transfer i; i exposure and erasing exposure, the surface charge of the photoreceptor drum 20 is reduced and made uniform, which improves the efficiency during transfer 9 separation.
To facilitate cleaning of 0hi afterimages.

〔Example〕

The present invention will be described below with reference to Examples, but the embodiments of the present invention are not limited thereby.

Example 1 Conductive support 1 consisting of a polyester film laminated with aluminum foil and a aluminum drum J
Then, an intermediate layer having a thickness of 0.1 μm made of vinyl chloride-vinyl acetate-maleic anhydride co-R combination (varnish MF-10, manufactured by Shimizu Kagaku Kogyo Co., Ltd.) was formed.

Next, polycarbonate resin (Panlite L-1250
, manufactured by Ondai Kasei Co., Ltd.) / CT M (IX-75) =
100/75 (RR1 ratio) was applied by dip coating to a 16.5 weight to 1 layer (Ttl 1,2-thyl ethane solution in the intermediate layer) to form a CTL with a thickness of 15μ.Next 4, 10-jib "1", which was promoted as CGM
Muang Xuan Throng (Vl-3)/Panlight L-
C,TM (lX-75) was crushed in a ball mill in 1,2-dichloroethane for 24 hours so that 1250 = 1/2 (weight ratio) was 9% by weight, and then dispersed for another 24 hours. 75 @ for 1250; A% and C
Exemplary compound (2) was added in an amount of 10 times to 1 time relative to TM.

Add 1 monochlorbenzene to this solution and add 1.2-dichlorobenzene/monochlorobenzene-7/3 (volume ratio).
The dispersion solution prepared to give the above-mentioned C'I"t was coated in a streaky manner on top of the C'I"t, and dried to form a CGL of 5 μm.

Photoreceptor sample 1 of the present invention was obtained by using photoreceptor layers having a laminated structure.

Comparative Example (1) A comparative photoreceptor sample (1) was obtained in exactly the same manner as in Example 1 except that Exemplary Compound (2) was omitted.

Example 2 Photoreceptor sample 2 was obtained in exactly the same manner as in Example 1 except that exemplified compound (3) was used instead of exemplified compound (2).

Example 3 On the photoreceptor layer (same as the photoreceptor of Comparative Example 1) except for Exemplified Compound (2) of Example 1, 1.55% of thermosetting acrylic-melamine-epoxy (1:l:1) resin was added. A coating solution prepared by dissolving 0.151 parts of compound (2) in a mixed solvent of monochlorobenzene/1,1,2-trichloroethane was coated with a stripe and dried. Photoreceptor sample 3 was obtained by using OCI with a thickness of 1 μm.

Example 4 On the photoreceptor layer excluding the exemplified compound (2) of Example 1, a primer for silicone hard coat P1191 (manufactured by Toshiba Silicon Co., Ltd.) was coated with a streak line of 0.1μ, and then -1- silicon hard coat toss guard 5
10 (manufactured by Toshiba Silicon Co., Ltd.) and Exemplary Compound (3) to 100 parts by weight of resin! Apply the solution added so that it becomes S without streaks, and dry it to form an OC with a thickness of 1 μm.
L was formed to obtain photoreceptor sample 4.

Example 5 Vinyl chloride-vinyl acetate-maleic anhydride copolymer (vinyl chloride-vinyl acetate-maleic anhydride copolymer
Made of varnish L Knock MP-10 (mentioned above) with a thickness of approximately 0.1
An intermediate layer of .mu.m was formed.

Next, as a coating liquid for CTL, butyral resin (varnish l knock BX-1, manufactured by Shimizu Chemical Co., Ltd.) 8iTi amount % and C'r
M (IX-75) 6% by weight methyl ethyl keto=
A coating solution obtained by dissolving in 7 is applied onto the intermediate layer.

It was dried to form a 10 μm thick CTL.

Next, apply C, GM (IV-7) 0.29 using Paint Conditioner.
, manufactured by Red Devi 1 Co., Ltd.) for 30 minutes, and polycarbonate resin (Panlite I, -1250, mentioned above) was added thereto at a concentration of 1.2-dichloroethane/l.

1.2- Add a solution of 0.5% by weight in a trichloroethane mixed solvent and disperse for 3 minutes, then add polycarbonate resin, CTM (IX-
75) and Exemplary Compound (2) at 3 and 3 i, respectively.
1? Amount %, 2.6wt rIt% and rJ, 26'
J? 1.2-dichloroethane, /1,1 so that the amount is %
．． A solution 19.19 obtained by dissolving in a 2-)-dichloroethane mixed solvent was added and further dispersed for 300 minutes. The thus obtained dispersion was coated onto the CTlj''- and dried to obtain photoreceptor sample 5 having a CC+ layer having a thickness of 5 μm and having a laminated structure.

Comparative Example (2) Same as Example 5 except that exemplified compound (2) was removed.
! Comparative photoreceptor sample (2) was prepared in exactly the same manner as in Example 5.
Tokunoko.

Example 6 Photoreceptor sample 6 was obtained in exactly the same manner as in Example 5, except that exemplified compound (3) was used instead of exemplified compound (2).

Example 7 OCL containing the same exemplified compound (2) as in Example 3 was installed in the photoreceptor layer (same as the photoreceptor of Comparative Example 2) excluding the exemplified compound (2) of Example 5 and L. , photoreceptor sample '7 was obtained.

Example 8 O CL containing the same exemplary compound (2) as in Example 4 was placed on the photoreceptor layer except for the exemplary compound (2) in Example 5.
was installed, and photoreceptor sample 8 was obtained.

+Fi Examples Samples 1 to 8 and Comparative Example Samples (1), (2
), we conducted a photo test of 20,000 yen against chargeability and a constant lzt measurement of sensitivity change due to UV exposure.

The chargeability live-action test was carried out using the image forming process of the present invention.
-L (ix 2812 M 11 (manufactured by Konishiroku Photo Co., Ltd.) modified experimental machine was equipped with a sample photoreceptor drum,
Positively charging the photoreceptor, repeating m cycles 20,000 times, which consists of each process including image exposure to the photoreceptor and fixing;
The positive charging potential at the beginning of the actual test is ) -y. , the positive charging potential after 20,000 cycles is shifted to +■1.

In addition, the sensitivity change due to UV exposure is determined by irradiating the sample sheet photoreceptor with ultraviolet rays of known intensity, and -+
The potential of the photoreceptor charged to 600V is 1-IQOV
11) The sensitivity S of the 8 photoconductors determined using @QC is defined as the relationship E"'(x:I'/S, and the smaller [>saa is, the greater the sensitivity S is and the sharper the contrast. Please change the image.

If the sensitivities before and after UV irradiation are So and S+, respectively, the reciprocal ratio Rs; (1/S +)/(1/S.)
= S o / S + represents UV resistance, and the larger Ijs is, the more UV resistance there is.

UV irradiation is done using a physical and chemical mercury lamp S II L-100
A photosensitive sheet cut from a sample film using UV-2 (manufactured by Toshiba Corporation) was placed at a distance of 30 cm, other electromagnetic waves were blocked, and irradiated with UV intensity of 1500 cd/am for 100 minutes to measure sensitivity. was measured using an electrostatic tester (Kawaguchi Electric Seisakusho, Model 5P-428).

These results are shown in Table 1.

Table 1 Note: Sample numbers in parentheses are comparative samples.

From Table 1, it can be seen that the photoreceptors of the present invention are both excellent in ultraviolet resistance and electrophotographic properties, whereas the comparative photoreceptors suffer from poor ultraviolet deterioration and have poor electrophotographic properties.

[Brief explanation of the drawing]

First! ! ! 1 to 3 are cross-sectional views of the rE-charged photoreceptor of the present invention. FIG. 4 is an explanatory diagram of the image forming block '7'.
Charge generation layer (CGL) 4... Photoreceptor layer 5... Charge transport material (CTM) 6... Charge generation layer (CGM) 7... Protective layer (OCL) 20... Photoreceptor 2! ... Charger 22 ... Developing device 26 ... Cleaner: Nog device 27, 28 and 29 ... Pre-exposure device Applicant: Konishi Rokushapei Kogyo Co., Ltd. Figure 4

Claims (3)

[Claims] (1) An electrophotographic photoreceptor having a layer containing a charge transporting substance and a charge generating substance on a conductive support, which contains a compound represented by the following general formula. Charged photoreceptor. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, A represents oxygen, a sulfur atom, or an imino group. R
_1 represents an aryl group or an allyl group, and the aryl group or allyl group may have a substituent. R represents an alkyl, amino, nitro, or alkoxy substituent substituting hydrogen or a halogen atom. n is 0, 1, or 2, and when n=2, R may be the same or different. ] (2) In the electrophotographic positively charging photoreceptor, a charge transport layer, a charge generation layer, and a protective layer provided as necessary are laminated in this order on a conductive support, and a charge transport substance is contained in the charge generation layer. 2. The positively charged electrophotographic photoreceptor according to claim 1, further comprising a compound represented by the general formula in the charge generation layer and/or a protective layer provided as necessary. (3) An image characterized in that, using the electrophotographic positively charged photoreceptor, a positive charge is applied to the photoreceptor, imagewise exposure is performed to form a positive electrostatic latent image, and toner development is performed. formation process.