JPS59149370A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To increase the sensitivity, the durability and the stability to a change in environment by forming a charge transferring layer contg. at least one kind of pyrazoline compound. CONSTITUTION:A pyrazoline compound represented by the formula and a binder such as polyester resin or polycarbonate are dissolved in a suitable solvent, and the soln. is coated and dried to form a charge transferring layer. The resulting sensitive body has increased sensitivity and reduced residual potential, and a reduction in the sensitivity and an increase in the residual potential can be inhibited when the sensitive body is repeatedly used. In the formula, each of R1- R7 is H, halogen or a univalent org. residue; at least one combination among R1 and R2, R3 and R4, R4 and R5, R5 and R6, and R6 and R7 may form an optionally substituted aromatic ring; R8 is optionally substituted aryl or azulenyl; R9 is optionally substituted aryl or a heterocyclic group; and n is 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-child photographic photoreceptor, and more particularly to a single-child photographic photoreceptor having a photosensitive layer containing a novel organic photoconductive substance consisting of a pyrazoline compound. .

BACKGROUND ART Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known as photoconductive materials used in electrophotographic photoreceptors. These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, or quickly dissipating the charge when irradiated with light. On the other hand, it also has various drawbacks. For example, in a selenium-based photoreceptor,
Crystallization easily progresses due to factors such as temperature, humidity, dust, and pressure, and especially when the ambient temperature exceeds 40° C., crystallization becomes significant, resulting in disadvantages such as a decrease in centricity and the appearance of white spots on images. Furthermore, selenium-based photoreceptors and cadmium sulfide-based photoreceptors have the disadvantage that stable sensitivity and durability cannot be obtained when used under high humidity over time.

In addition, zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal, but such sensitizing dyes cause charge deterioration due to corona charging and photobleaching due to exposure light, so it may take a long time. It has the disadvantage that it cannot provide a stable image over a long period of time.

On the other hand, various organic photoconducting polymers have been proposed, including polyvinylcarbazole, but these polymers are inferior to the aforementioned inorganic photoconductive materials in terms of film formability, light weight, etc. Despite this, it has been difficult to put it into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic-based It was found to be inferior to photoconductive materials. In addition, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, triarylpyrazoline compounds described in U.S. Pat. Low-molecular organic photovoltaic materials have been proposed, such as the 9-steryl anthracene compound described above and the 4-chlorooxazole compound described in JP-A-55-53278. By appropriately selecting the binder used, such low-molecular-weight organic photoconductive materials can overcome the drawbacks of film-forming properties that had been a problem in the field of organic photoconductive polymers. It cannot be said that the sensitivity is sufficient.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a novel electrophotographic photoreceptor that eliminates the above-mentioned drawbacks or disadvantages.

Another object of the invention is to provide new organic photoconductive materials.

Another object of the present invention is to provide a compound suitable as a charge transport substance used in a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer.

Structure and effect of the invention This object of the present invention is represented by the following general formula (1).

This is achieved by a Seiko photographic photoreceptor having a layer containing at least 14 Jfl of a pyrazoline compound.

5 In the formula, R1 to R7 represent a hydrogen atom, a chlorine atom (chlorine atom, bromine atom, iodine atom), or a monovalent organic residue. Monovalent Ω organic residues can be selected from a wide variety of groups, but especially alkyl groups (methyl, ethyl, n-
Propyl, isopropyl, n-butyl, t-butyl, n
-amyl, n-hexyl, n-octyl, 2-ethylhexyl, t-octyl, etc.), alkoxy groups (methoxy, ethoxy, propoxy, butoxy, etc.), substituted or unsubstituted aryl groups (phenyl, tolyl, xylyl, ethylphenyl) , methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl, dimethylaminophenyl, α-naphthyl, β-naphthyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenylethyl, etc.)
-Phenyl-1-methylethyl, bromobenzyl, 2-
7'romophenyl edyl, methylbenzyl, methoxybenzyl, nitrobenzyl), anlu group (acetyl, flopionyl, butyryl, valeryl, benzoyl, triooyl, naphthoyl, 7taloyl, furoyl, etc.), substituted or unsubstituted amine group (amine , dimethylamino, diethylamino, dipropylamino, acetylamino, benzoylamino, etc.), substituted or unsubstituted styryl groups (styryl, dimethylaminostyryl, diethylaminostyryl,
dipropylaminostyryl, methoxystyryl, ethoxystyryl, methylstyryl, etc.), nitro group, hydroxy group, carboxyl group, cyano group, and substituted or unsubstituted arylazo group (phenylazo, α-naphthylazo,
β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo, tolylazo, etc.). In addition, among the combinations of R1 and R2, R3 and R4, R4 and R5, R5 and R6, and R6 and R7, at least one combination of substituted or unsubstituted aromatic rings (benzene, naphthalene, chlorobenzene, bromobenzene, methylbenzene,
Ethylbenzene, methoxybenzene, ethoxybenzene, etc.) may be entirely formed.

R8 is a substituted or unsubstituted aryl group (phenyl, tolyl, ethylphenyl, dimethylaminophenyl, diethylaminophenyl, α-naphthyl, β-naphthyl, etc.)
and a substituted or unsubstituted azulenyl group (azulenyl, 3
-methylazulenyl, 4,6.8-) IJ methylazulenyl, 5-ituprovir-3,8-:)methylazulenyl, 6-phenyl-4,8-)methylazulenylnato).

R9 represents a substituted or unsubstituted aryl group (phenyl, tolyl, xylyl, ethylphenyl, dimethylaminophenyl, α-naphthyl, β-7thyl, etc.) and a substituted or unsubstituted heterocyclic group (pyridyl, quinolyl, 2 -benzothiazolinyl, etc.).

n is an integer of 0 or 1.

Specific examples of the pyrazoline compound represented by the general formula (1) are listed below.

H3 0) (3 H3 H3 1 a3 These compounds can be used alone or in combination of two or more.

These pyrazoline compounds represented by general formula (1) are carbonyl compounds represented by general formula (2) and general formula (2) formula 5 (wherein R1, R2, R3, R4, R5, R6, R7
, R8 and n have the same definitions as defined above. ) The hydrazine compound represented by the general formula (3) is converted to the hydrazine compound represented by the general formula (6).
) % formula % (wherein R9 has the same definition as defined above).

The electrophotographic photoreceptor containing the pyrazoline compound represented by the general formula (1) can be applied to any type of electrophotographic photoreceptor using an organic photoconductive substance, but the preferred type is: 1) Electron-donating property A direct cargo transfer complex formed by a combination of a substance and an electron-accepting substance.

2) An organic photoconductor sensitized by adding a dye.

'5) Hole Ma) IJ Lux pigment dispersed.

4) The charge generation layer and the charge transport layer contain 100% of Tsukiyome and 100% of the charge transport layer.

5) Those whose main components are a eutectic complex consisting of a dye and a resin and an organic photoconductor.

6) A charge transfer complex in which an organic or inorganic charge generating material is added.

Among them, the most desirable types are 6) to 6).

Furthermore, in the case of a 4) type photoreceptor, that is, a pyrazoline compound represented by general formula (1) is used as a charge transport material for the charge transport layer of a photoreceptor that is functionally separated into two layers: a charge generation layer and a charge transport layer. When used, the sensitivity of the photoreceptor is particularly improved and the residual potential is low. Further, in this case, the decrease in sensitivity and the increase in residual potential during repeated use can be suppressed to a negligible level in practical use. Therefore, the 4) type of photoreceptor will be described in detail.

As for the layer structure, a conductive layer, a charge generation layer, and a charge transport layer are essential.The charge generation layer may be either above or below the charge transport layer, but it is not suitable for electrophotographic photoreceptors of the type that are used repeatedly. In this case, it is preferable to laminate a conductive layer, a charge generation layer, and a charge transport layer in this order, mainly from the viewpoint of physical strength and, in some cases, from the viewpoint of chargeability. An adhesive layer may be provided as necessary for the purpose of improving the adhesiveness between the conductive layer and the charge generation layer.

The charge transport layer used in the present invention is preferably formed by applying a solution of the pyrazoline compound represented by the general formula (1) and a binder dissolved in a suitable solvent and drying the solution.

As the binder used here, e.g. polysulfone,
Acrylic resin, methacrylic level 1. ] Copolymer resins containing two or more of the repeating units of these resins include vinyl resins, vinyl acetate resins, phenolic resins, epoxy resins, polyester resins, alkyd resins, polycarbonates, polyurethanes, and other repeating units of these resins. It is possible,
Particularly preferred are polyester resin and polycarbonate. Furthermore, photoconductive polymers which themselves have charge transporting ability, such as poly-N-vinylcarpazole, can also be used as binders.

The blending ratio of the binder and the charge transport compound is 1
It is preferable that the charge transport compound is contained in an amount of 10 to 500 parts by weight per 00 parts by weight. The thickness of this charge transport layer is 2 to 10
0 micron, preferably 5 to 30 micron. In addition, coating methods used when providing the charge transport layer include blade coating method, Mayer-Per coating method,
Conventional methods such as spray coating, dip coating, bead coating, and air knife coating can be used.

Further, the solvent used in forming the charge transport layer of the present invention includes many useful organic solvents. Typical examples include aromatic hydrocarbons such as benzene, naphthalene, toluene, xylene, mesitylene, and chlorobenzene, ketones such as acetone and 2-butanone, and rhodanization of ichmethylene salt, chloroform, and ethylene chloride. Examples include aliphatic hydrocarbons, cyclic or linear ethers such as tetrahydrofuran and ethyl ether, and mixed solvents thereof.

The charge transport layer of the present invention can contain various additives. Such additives include diphenyl, diphenyl chloride, 0-terphenyl, P-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorine paraffin, dilaurylthiopropionate. , 6,5-dinitoof' ricylic acid, various fluorocarbons, silicone oil, silicone rubber or dibutylhydroxytoluene, 2.2'-
methylene-bis-(6-t-butyl-4-methylphenol), α-toco7xco-/L/, 2-t-octyl-5-chlorohydroquinone, 2,5-di-t-octylhydroquinone, etc. Examples include phenolic compounds.

As the charge generation material used in the charge generation layer, any material can be used as long as it absorbs light and generates charge carriers with extremely high efficiency. Preferred materials include selenium, selenium, etc. Inorganic substances such as tellurium, selenium/arsenic, cadmium sulfide, amorphous silicon, birylum dyes, thiopyrylium dyes, triarylmethane dyes, thiazine dyes, cyanine dyes, phthalocyanine pigments, poryl pigments, indigo pigments, Examples include organic substances such as voindigo pigments, quinacridone pigments, squaric acid pigments, azo pigments, polycyclic quinone pigments, and azulenium salt compounds. The thickness of the charge generation layer is preferably 5 microns or less, preferably 0.005 to 3 microns.

Representative examples of charge generating substances that can be used in the present invention are shown below.

Charge generating substance (1) Amorphous silicon (2) Selenium-tellurium (6) Selenium/arsenic sulfide cadmium 1 02H5c2u5 (a) C2H502H5 cH3 These compounds can be used alone or in combination of two or more.

In the present invention, when forming a charge generation layer using the above-mentioned compound, a layer of the above-mentioned compound can be formed by vacuum evaporation, sputtering, glow discharge, or the like.

Alternatively, a layer can be formed by dispersing the above-mentioned compound in a suitable binder and applying this dispersion by a suitable coating method. In addition, the layer of the above-mentioned compound can also be formed in the form of S ingu free. When dispersing the above-mentioned compound, it can be dispersed by a known method using a ball mill, an attritor, etc., and the particle size is 5 microns or less, preferably 2 microns or less, and optimally 0.5 microns or less.
It is desirable that the thickness be less than microns. In addition, the above-mentioned compounds can be used as amines such as ethylenediamine, diethylenetriamine, tetraethylene, ethamine, ethylethylenehexamine, diethylaminopropylamine, N-aminoethylpiperazine, benzyldimethylamine, α-methylbenzyldimethylamine, and tridimethylaminomethylphenol. It can also be applied by dissolving it in a solvent. As a coating method, conventional methods such as a blade coating method, a Mayer-Per coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method can be used.

The thickness of the charge generation layer used in the present invention is 5 microns or less,
Preferably, 0.01 micron to 1 micron is appropriate.

Binders for dispersing the aforementioned compounds include polyvinyl butyral, polymethyl methacrylate, polyester, polyvinylidene chloride, polyamide, chlorinated rubber,
polyvinyltoluene, polystyrene, polyvinyl chloride,
Examples include ethyl cellulose, polyvinylpyridine, and styrene-maleic anhydride copolymer. The proportion of such a binder in the charge generation layer is 80% by weight or less, preferably 50% by weight, of the total weight of the charge generation layer.
The following are desirable.

In addition, in the electrophotographic photoreceptor of the present invention, in order to uniformly inject carriers into the charge transport layer above the charge generation layer, the surface of the charge generation layer can be polished to a mirror finish, if necessary. .

As a mirror finishing method, for example, Japanese Patent Application Laid-Open No. 55-15535
<The method disclosed in Publication No. S can be used.

The conductive layer may be any type of conductive layer conventionally used as long as it is imparted with conductivity.

Materials for the adhesive layer include casein, polyvinyl alcohol, nitrocellulose, hydroxymethylcellulose,
Various conventional binders such as polyamide can be used.

The thickness of the adhesive layer is suitably 0.1 to 5 microns, preferably 0.5 to 3 microns.

The pyrazoline compound used in the present invention has hole-transport properties, and when using a photoreceptor in which a conductive layer, a charge generation layer, and a suitable transport layer are laminated in this order, the surface of the charge transport layer must be made negative. It needs to be charged, and when exposed to light, holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, and then reach the surface and neutralize the negative charge, resulting in a decrease in surface potential and the unexposed area. An electrostatic contrast occurs between the two.

Various conventionally used developing methods can be used to make the image visible.

(4) With regard to photoconductors other than the above types, implementation modes are described in numerous patent publications and documents that have been proposed so far, so a detailed description will be omitted here. The pyrazoline compounds of the present invention are also effective.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in a wide range of electrophotographic applications such as laser printers, CRT printers, and electrophotographic plate making systems.

Next, examples of the present invention will be shown.

Example 1 Aqueous ammonia solution (11.2 m of casein, 128 m of ammonia, 222 m of water) was placed on an aluminum plate.
Coated with Meyer Par and dried, coating amount 1.017' /
An adhesive layer of m2 was formed. Next, disazo pigment 52 having the following structure and 2 vol of butyral resin (degree of butyralization 66 mol%) were dispersed together with a solution dissolved in 95 ml of ethanol, and then coated on the adhesive layer. ,25'/rn2
Forms a charge generation layer (~).

Next, the pyrazoline compound Nα(2) 5 F , poly-4,47-, oxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 30,000) 5 f
A solution prepared by dissolving 150 rnl of dichloromethane was applied onto the charge generation layer and dried to form a charge transport layer with a coating weight of 101/rn2.

The electrophotographic photoreceptor thus prepared was statically charged at 05 KV using an electrostatic copying paper tester Model 5P-428 manufactured by Kawaguchi Denki, and after being held in a dark place for 10 seconds, the illuminance was 5 lux. The charging characteristics were investigated by exposing the sample to light.

The charging characteristics of the present photoreceptor are shown by taking the initial potential ■o(v), the potential holding rate for 10 seconds in the dark as Rv(sub), and the decay exposure amount E)(lux·8eC).

Vo: (E1520vo/I/)Rv:
84"3 < : 8.71ux・sec Example 2 Azlenium salt compound 52 having the following structure butyral resin (degree of butyralization 66 mol%) 22 was mixed with ethanol 9
After dispersing with the liquid dissolved in 5- (7), it was coated on the adhesive layer prepared in Example 1, and the coating amount after drying was 0.2 f 7
A charge generation layer of m2 was formed.

Next, a solution prepared by dissolving the pyrazoline compound Nα(5) 5 F and poly-4,4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 50,000) 5 f in 150 +++ liters of dichloromethane was applied onto the charge generation layer. The coating was applied and dried to form a charge transport layer having a coating amount of 1 Of' 7 m2.

The charging characteristics of the electrophotographic photosensitive plate thus prepared were examined in the same manner as in Example 1. The results are shown below.

Vo: θ480 point Rv: 8 [1 drop: 6.51 ux-esc Examples 3 to 10 The following pigments were vacuum deposited on an aluminum plate with a thickness of 100 μm to form a charge generation layer with a thickness of 0.15 μm.

Kuni polyester resin (Byron 200. Toyo 1ful
i■) 51 and the exemplified pyrazoline compound 5 shown in the following table
v and 150 rnl of dichloromethane, respectively.

A solution dissolved in
A charge transport layer of 1 t/m2 was formed.

The charging characteristics of the electrophotographic photoreceptor thus prepared were examined in the same manner as in Example 1, and the results are shown in the following table.

Example 11 Selenium/tellurium (10% tellurium) was vacuum deposited on an aluminum plate to form a charge generation layer with a thickness of 0.8 μm.

Next, the same charge transport layer as used in Example 1 was coated and dried to give a coating weight of 11 f/m2.

The charging characteristics of the electrophotographic photosensitive plate thus prepared were examined in the same manner as in Example 1, and the results are shown below.

v, : e470 volts Rv: 80 Bg: 8.51 uX'Sec Example 12 Pyrazoline compound used in Example 1) kl(6)5F and poly-N-vinylcarbazole (molecular weight 500,000) 5f in dichloromethane 150 mJ Add β-type copper phthalocyanine to the dissolved solution.1. Off was added and after dispersion, it was applied onto the aluminum casein layer provided with the force-in layer used in Example 1, and the coating amount after drying was set to 105'/m2.

Charge measurement of the photoreceptor thus prepared was carried out in the same manner as in Example 1, and the results are shown below.

However, the charging polarity was set to ■.

vo: ■510 volts Rv: 74% Viscosity: 18.51 ux φθec Example 16 A molybdenum plate (substrate) with a thickness of 0.2 W and whose surface was cleaned was fixed at a predetermined position in a glow discharge deposition tank.

The inside of the tank was thoroughly evacuated to a vacuum level of about 5 x 10-' torr. Thereafter, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150°C.

Then hydrogen gas and silane gas (15 volume i for hydrogen gas)
%) was introduced into the tank and stabilized at Q, 5 torr by adjusting the gas flow rate and the main valve of the deposition tank.

Next, 5 MHz high frequency power was applied to the induction coil to generate a glow discharge inside the coil in the tank, resulting in an input power of 6°W. An amorphous silicon film was grown on the substrate under the above conditions, and the same conditions were maintained until the film thickness reached 2 microns, after which glow discharge was discontinued. After that, turn off the heating heater and high-frequency power supply, wait for the substrate temperature to reach 100°C, close the hydrogen gas and silane gas outflow valves, and once the inside of the tank is below 10-” torr, return to atmospheric pressure and remove the substrate. Next, a charge transport layer was formed on this amorphous silicon layer in exactly the same manner as in Example 1.

The photoreceptor thus obtained was installed in a charging exposure experimental device.
It was corona charged at 6 KV and immediately irradiated with a light image. The light image was illuminated through a transmission type test chart using a tungsten lamp light source.

Immediately thereafter, a good toner image was obtained on the photoreceptor surface by cascading a charging station, the image side (containing toner and carrier), onto the photoreceptor surface.Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor comprising a layer containing at least one compound represented by the following general formula (1). General formula (1) (wherein R1, R2, R3, R4, R5, R6 and R7
represents a hydrogen atom, a halogen atom, or a monovalent organic residue; parent, period and R2, R3 and R4, R4 and R5, R5 and R6
At least one combination of R6 and R7 may form a monosubstituted or unif-substituted aromatic ring. R8 represents a substituted or unsubstituted aryl group or azulenyl group. R9 represents a substituted or unsubstituted aryl group or a heterocyclic group. n represents an integer of O or 1. )