JPS59191059A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enable formation of sharp transferred image and to enhance durability by incorporating a specified hydrazone compd. in a photosensitive layer. CONSTITUTION:A photosensitive body contains a hydrazone compd. represented by general formula I in which R1-R7 are each H or halogen or an org. monovalent residue, and at least one combination of R1 and R2, R3 and R4, R4 and R5, R5 and R6, and R6 and R7 may form an optionally substd. aromatic ring; R8 is H, optionally substd. alkyl or aryl; R9, R10 are each optionally substd. alkyl or aryl; (A) is a divalent org. residue; and (n) is 0 or 1. Said compd. is especially useful for the photosensitive body of a laminated type of a charge generating layer and a charge transfer layer. As a charge generating material, amorphous Si, Se-Te, CdS, azo pigments, etc. can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a novel organic photoconductive substance comprising a hydrazone 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 a number of advantages, such as being able to be charged to transparent potentials in the dark, having little charge dissipation in the dark, or rapidly dissipating the charge when irradiated with light. On the other hand, it has various drawbacks. For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, and pressure.
In particular, when the ambient temperature exceeds 40° C., crystallization becomes significant, resulting in drawbacks such as a decrease in chargeability and the appearance of white spots on images. -1: Furthermore, selenium-based photoreceptors and cadmium sulfide-based photoreceptors have the disadvantage that stable sensitivity and durability cannot be obtained when used over time under high humidity.

In addition, zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal, but these sensitizing dyes cause charging deterioration due to corona charging and photobleaching due to exposure light. Therefore, it has the disadvantage that it is not possible to obtain a stable image in all directions over a long period of time.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior to the above-mentioned inorganic photoconductive materials in terms of film formability, lightness, and other aspects. However, it has been difficult to put it into practical use today because sufficient film formation properties have not yet been obtained, and inorganic photoconductive materials have poor sensitivity, durability, and stability against environmental changes. This was because the material was inferior. In addition, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, triarylvirasorin compounds described in U.S. Pat.
Low-molecular organic photoconductive compounds such as 9-styrylanthracene compounds described in -94s2s+5 and % 1982-94829, and 4-chlorooxazole compounds described in % 1982-53278-q, etc. materials are proposed. By appropriately selecting the binder used, these low-molecular-weight organic photoconductive materials have been able to overcome all of the film-forming defects that had been a problem in the field of organic photoconductive polymers. 1 cannot be said to be sufficient in terms of sensitivity.

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 present invention is to provide novel organic phototetraelectric materials.

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

Structure and Effects of the Invention The objects of the present invention are achieved by an electrophotographic photoreceptor having a layer containing at least one hydrazone compound represented by the following general formula (1).

General formula (1) In the formula, R1 to R7 represent a hydrogen atom, a halogen atom (chlorine atom, bromine atom, iodine atom) or a monovalent organic residue. Monovalent organic residues can be selected from a wide variety of groups, but especially alkyl groups (methyl, ethyl, n-
propyl, inpropyl, n-7'thyl, 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, ethyl phenyl, methoxyphenyl, ethoxyphenyl, chlorophenyl, nitrophenyl, dimethylaminophenyl, α-7tyl, β-naphthyl, etc.), substituted or unsubstituted aralkyl groups (benzyl, 2-phenylethyl, 2-phenyl-1- jf ethyl, bromobenzyl, 2-bromophenylethyl, methylbenzyl, methoxybenzyl, nitrobenzyl, acyl group (acetyl, propionyl, butyryl, valeryl, benzoyl,
trioyl, naphthoyl, phthaloyl, furoyl, etc.)
, substituted or unsubstituted amino groups (amino, nnotylamino, diethylamino, dipropylamino, acetylamine, benzoylamino, etc.), substituted or unsubstituted styryl groups (styryl, dimethylaminostyryl, diethylaminostyryl, dipropylaminostyryl, methoxy) styryl, ethoxystyryl, methylstyryl, etc.)
2l, hydroxy group, carboxyl group, cyan group, or substituted or unsubstituted arylazo group () enylazo, α-naphthylazo, β-naphthylazo, dimethylaminophenylazo, chlorophenylazo, nitrophenylazo, methoxyphenylazo , tolyluazo, etc.)
can be mentioned. Also, R1 and R2, R3 and R4,
Among the combinations of R4 and R5, R5 and R6, and R6 and R7, substituted or unsubstituted aromatic rings (benzene, naphthalene, chlorobenzene, bromobenzene, methylbenzene, ethylbenzene), methoxybenzene, ethoxybenzene, etc.) may be formed entirely.

R8 is a hydrogen atom or an optionally substituted alkyl group (e.g., methyl group, ethyl group, n-propyl group, n
-butyl group, t-butyl group, n-amyl group, t-amyl group, n-octyl group, t-octyl group, benzyl group, chlorobenzyl group, dichlorobenzyl group, methylbenzyl group, methoxybenzyl group, 2- Phenylethyl group, α-
naphthylmethyl group, β-naphthylmethyl group, allyl group] or aryl group (phenyl group, tolyl group, xylyl group, biphenyl group, chlorophenyl group, dichlorophenyl group, trichlorophenyl group, bromophenyl group,
(cyfuromophenyl group, tribromophenyl group, methoxyphenyl group, phenoxyphenyl group, acetylphenyl group, benzoylphenyl group, α-naphthyl group, β-naphthyl group, etc.).

R9 and R'IO are optionally substituted alkyl groups (e.g., methyl group, ethyl group, n-propyl group, n-propyl group,
-butyl group, t-butyl group, n-amyl group, t-amyl group, n-octyl group, -octyl group, benzyl group, chlorobenzyl group, dichlorobenzyl group, methylbenzyl group, methoxybenzyl group, 2- Phenylethyl group, α-
Naphthylmethyl group, β-naphthylmethyl group, allyl group) or Tezuma 56□ group (phenyl group, tolyl group,
(xylyl group, biphenyl group, chlorophenyl group, dichlorophenyl group, trichlorophenyl group, bromophenyl group, cyfromophenyl group, tribromophenyl group, methoxyphenyl group, phenoxyphenyl group, acetylphenyl group, benzoylphenyl group, etc.).

A indicates the divalent organic residual fund. Specific divalent organic residues include alkylene groups such as methylene, ethylene, propylene, and butylene, arylene groups such as phenylene, naphthylene, and hypophenylene, or pyridine;
Examples include divalent heterocyclic groups derived from quinoline, carbazole, phenothiazine, and phenoxazine. Other examples include O□Q kill. These two
Valid organic residues include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, amyl group, octyl group, halogen atoms such as chlorine atom, bromine atom, and iodine atom, methoxy group, ethoxy group, and propoxy group. , alkoxy groups such as butoxy groups, nitro groups, cyano groups, dimethylamino groups,
Substituted amine groups such as diethylamino group, dipropylamino group, dibutylamino group, dibenzylamino group, diphenylamino group, acylamino group such as acetylamino group, propionylamino group, butyrylamino group, benzoylamino group, trioylamino group, hydroxy It can also be substituted with groups, carboxyl groups, sulfo groups, etc.

n is an integer of 0 or 1.

Specific examples of the hydrazone compound represented by the general formula (1) used in the present invention are listed below.

(6) (4) (5) (6) (7) (8) C bow
C85 (9) (10) (1sl
CH2CH2 (16) (14) These hydrazone compounds represented by general formula (1) are carbonyl compounds represented by general formula (2) and general formula (2) (However, R1, R2, R3, R4, R5, R6 ,R7,
R8 and n have the same definitions as defined above.O) It can be synthesized by a conventional method using a hydrazine compound represented by the general formula (3).

General formula (3) % formula % (However, R9, RID and A have the same definition as defined above.) As an electrophotographic photoreceptor containing a hydrazone compound represented by general formula (1), The method can be applied to any type of electrophotographic photoreceptor using an organic photoconductive substance, but preferred types include 1) one in which a charge transfer complex is formed by a combination of an electron-donating substance and an electron-accepting substance.

2) An organic photoconductor sensitized by adding a dye.

3) Pigment dispersed in a hole matrix.

4) Functionally separated charge generation layer and 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, types 3) to 6) are desirable.

Furthermore, in the case of a 4) type photoreceptor, that is, a hydrazone 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, a decrease in sensitivity and an increase in residual potential during repeated use can be suppressed to a practically negligible level. 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 placed above or below the charge transport layer, but in an electrophotographic photoreceptor of the type that is used repeatedly. 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 a hydrazone compound represented by the general formula (1) and a binder dissolved in a suitable solvent and drying the solution.

Examples of the binder used here include polysulfone, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, and recycled resins of these resins. Examples include copolymer resins containing two or more of the return units, with polyester resins and polycarbonates being particularly preferred. Furthermore, photoconductive polymers that themselves have charge transporting ability, such as poly-N-vinylcarbazole, 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. Further, coating methods used when providing the charge transport layer include blade coating method, Mayer bar 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 FAs such as benzene, naphthalene, toluene, xylene, mesitylene, and chlorobenzene, hydrogen hydrides, ketones such as acetone and 2-butanone, and halogenated fats such as methylene chloride, chloroform, and ethylene chloride. Group hydrocarbons, cyclic or linear ethers such as hydrofuran, ethyl ether, etc., or kneads.

Examples of mixed solvents include:

The charge transport layer of the present invention can contain various additives. Such additives include diphenyl, diphenyl chloride, 0-terphenylene, P-p-phenyl, dibutyl phthalate, dimethyl glycol tucrate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated/2-loughin, and nlauryl. Thimebrobione-1.,6,5-dinitroturityl e
, various fluorocarbons, silicone oil, silicone rubber or dibutylhydroxytoluene, 2.2'-
Notylene bis-(6-t-butyl-4-methylphenol 9, α-tocopherol, 2-t-octyl-5-
Examples include fe/lipid compounds such as croconoidroginone and 2,5-di-t-octylneudroginone.

As a charge generation material used in the charge generation layer, fi is a material that absorbs light and generates a charge phase with extremely high efficiency.
No. 9 materials can be used, and preferred materials include selenium, selenium/tellurium, selenium/arsenic, cadmium sulfide, amorphous silicon, zero inorganic substances, birylum dyes, thiopyrylium dyes, Triarylmecne dyes, thiazine dyes, cyanine dyes, phthalocyanine thread pigments, perylene pigments, indigo pigments, thioindigo pigments, quinacridone pigments, squaric acid pigments, azo pigments (monoazo, disazo, trisazo), Examples include organic substances such as polyquinone pigments and azulenium salt compounds. The thickness of the charge generation layer is preferably 5 μm or less, preferably 0.05 to 3 μm.

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

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.

The above-mentioned compound can be dispersed in a suitable binder, and the dispersion can be applied by a suitable coating method to form a layer. In addition, the layer of the above-mentioned compound can also be formed in a binder-free manner. When the above-mentioned compound is completely dispersed, it can be dispersed by a known method using a ball mill, an attritor, etc., and the particle size should be 5 microns or less, preferably 2 microns or less, and optimally 0.5 microns or less. This is desirable. In addition, the above-mentioned compounds were added to ethylene diamine, diethylene triamine, tetraethylene to ethamine, ivy ethylene hexamine, diethylamine propylamine, N-aminoalbi to radin,
It can also be applied by dipping in an amine solvent such as benzyldimethylamine, α-methylbenzyldimethylamine, +-phosphorusmethylaminemethylphenol. As a coating method, conventional methods such as a blade coating method, a Meyer bar 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 preferably 5 microns or less, preferably 0.01 micron to 1 micron.

Binders for dispersing the aforementioned compounds include polyvinyl butyral, polymethyltutaacrylate, polyester, polyvinylidene chloride, polyamide, chlorinated rubber,
Polyvinyltoluene, polystyrene, polyvinyl trichloride,
Ethylcellulose, 'h') vinylhyricine, styrene-maleic anhydride copolymer, etc. can be used. The proportion of such a binder in the charge generation layer is desirably 80% by weight or less of the total weight of the charge generation layer, and preferably 5ON% or less relative to the total weight of the charge generation layer.

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 for mirror finish, for example, Japanese Patent Application Laid-Open No. 55-15535
The method disclosed in Japanese Patent Publication No. 1, No. 1 can be used.

The conductive layer only needs to be imparted with conductivity, and any conventionally used conductive layer may be used.

As the material for the adhesive layer, various conventional materials such as casein, polyvinyl alcohol, nitrocellulose, hydroxymethyl cellulose, and polyamide can be used.

The thickness of the adhesive layer is 0.1 to 5 microns, preferably 0.5 to 5 microns.
6 microns is suitable.

The hydrazone compound used in the present invention has hole transport properties, and when using a photoreceptor in which a groove side charge generation layer and a charge transport layer are laminated in this order, the surface of the charge transport layer must be negatively charged. When exposed to light, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area, and then reach the surface and neutralize the negative charge, causing a decrease in surface potential and creating an electrostatic contrast between the exposed area and the unexposed area. occurs.

Various conventionally used developing methods can be used for visualization.

Regarding photoreceptors other than the (4) type, implementation aspects are described in numerous patent publications and documents that have been proposed so far, so a detailed description will be omitted here, but these types of photoreceptors The hydrazone compounds of the present invention are also effective for the body.

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 An ammonia aqueous solution of camoin (casein 1) was placed on an aluminum plate.
1.2f', 28% ammonia water 12%, water 222%) was applied with a Mayer bar and dried, coating amount 1. .

7 m2 of adhesive layer was formed. Next, disazo pigment 5t having the following structure and butyral resin (butyralization degree 63 mol% 922 dissolved in ethanol 95d) were dispersed together, and then coated on the adhesive layer to give a coating weight of 0.2S' after drying. A charge generation layer of /m2 was formed.

Next, a solution prepared by dissolving the hydrazone compound No. (3) 5 y, poly-4,4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 30,000) 5 f in dichloromethane 150- was poured onto the charge generation layer. After applying and drying, the coating amount was 10? /m2 of charge transport layer was formed.

The electrophotographic photoreceptor prepared in this manner was statically charged with corona at 5 KV using an electrostatic copying paper tester Model 5P-428 manufactured by Kawaguchi Denki (→5 KV), and then subjected to corona charging in a dark place for 1
After holding for 0 seconds, it was exposed to light at an illuminance of 51 ux to examine charging characteristics.

Initial potential “O (■), potential retention rate f for 10 seconds in the dark
f: Rv (%), half-attenuation exposure fi: f E% (lu
x・5ee) shows the charging characteristics of this photoreceptor.

■O: 510 volts Rv: 80% E: 9.51 ux mouth eec Example 2 Azlenium salt compound 52 having the following structure and butyral resin (degree of butyralization: 63 mol%, 921, dissolved in 95 ml of total ethanol) were dispersed together. After that, it was coated on the adhesive layer prepared in Example 1, and the coating amount after drying was 0.2?/m.
Two charge generation layers were formed.

Next, the hydrazone compound N0(7)! 1M, poly-4
, 4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 30,000) 5f dissolved in 150 tnl of dichloromethane was placed on the charge generation layer.
After coating and drying, a charge transport layer with a coating weight of 10 f/m2 was completely formed.

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.

v, ): e480 Porto Rv near 5% EW: 13.51ux-sec Examples 3-1
1 The following pigment was vacuum deposited on an aluminum plate with a thickness of 100 microns to form a charge generation layer with a thickness of 0.15 microns.

Next, polyester resin (Byron 2oo, Toyobo ■)
A solution prepared by dissolving each of the 51 exemplified human dicine compounds shown in Table 1 in 150 ml of dichloromethane was applied onto the charge generating layer and dried to form a charge transporting layer having a coating amount of 1197 m2.

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

3 (1) 480 80 10.54
(2) 470 82 9.05
(4) 490 78 14.56 (
6) 500 74 20.57 (8)
470 75 1as8 (in)
510 80 14.59 (11)
520 82 11.01D (13)
460 81 14.011 (14)
520 84 2aO Example 12 Selenium/tellurium (tellurium 10%) was vacuum deposited on an aluminum plate to form a charge generating layer N having a thickness of 08 microns.

Next, the same charge transport layer as used in Example 1 was applied and dried to a coating weight of 11? /m2 and (7ta.

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.

vo: e 480 volts 1 (y: 81% R'V2.: 8.51 ux-secExample 13 Hydrazone compound used in Example 1 p (5) 5 y
and poly-N-vinylcarbazole (molecular weight 600,000) 5?
β-type copper phthalocyanine 1. is dissolved in dichloronotane 150 Inf. After adding Q t 1.1 and dispersing,
It was applied onto the casein layer of the aluminum plate provided with the casein layer used in Example 1, and the total coating amount after drying was IQ? /
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: Q520 volts Rv: 84 articles Fj72: 22.51 ux-sec Example 14 A 02 thick molybdenum plate (substrate) with a clean surface was fixed at a predetermined position in a glow discharge deposition tank. Next, the tank was completely evacuated to a vacuum level of about 5 x 10-6 torr. Thereafter, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150°C.

Thereafter, hydrogen gas and silane gas (15 torr for hydrogen gas) were introduced into the tank, and the gas flow rate and the main valve of the deposition tank were adjusted to stabilize the pressure at l'3.5 torr.

Next, 5 MHz high-frequency power was fully applied to the induction coil (the glow was dissipated inside the coil in one tank; all the power was generated and the input power was 60 W. Under the above conditions, an amorphous silicon film was grown on the substrate and the film thickness increased. After maintaining the same conditions at 2 microns, the glow discharge was stopped.After that, the heating heater and high frequency power supply were all turned off, and the substrate temperature reached 100°C. ,
Once the inside of the tank was lowered to below 10-'' torr, the pressure was returned to atmospheric pressure, and the substrate was taken out. Next, a charge transport layer was formed on the amorphous 7 recon layer in exactly the same manner as in Example 1.

The photoreceptor obtained in this way was installed in a charging exposure experiment equipment and
It was corona charged at 6 KV and immediately irradiated with a light image. A light image was illuminated over the entire transmission type test chart using a tungsten lamp light source.

Immediately thereafter, a good toner image was obtained on the surface of the photoreceptor by cascading a chargeable developer (including toner and carrier) over the entire surface of the photoreceptor.

Patent applicant: Canon Co., Ltd.

Claims (1)

[Scope of Claims] 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,
Furthermore, at least one combination of R1 and R2, R3 and R4, R4 and R5, R5 and R6, and R6 and R7 may form a substituted or unsubstituted aromatic ring. R8
represents a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group. R9 and R10 represent a substituted or unsubstituted alkyl group or aryl group. A (represents the divalent organic residual fund. n ij Ol or an integer of 1.)