JPS5816242A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To improve sensitivity, durability, stability, and film-forming property, by forming a layer containing a specified hydrazone type compound on an electrophotographic receptor. CONSTITUTION:An electrophotographic receptor has a layer containing a compound represented by formulaIin which R1 are H or aryl, e.g. phenyl or anthryl, or heterocyclic, e.g. pyridine or phenothiazine; R3, R4 are alkyl, e.g. methyl or n-propyl, aralkyl, e.g. benzyl or alpha-naphthylmethyl, aryl or heterocyclic; and R5 is a divalent organic group, e.g. alkylene or arylene, or a divalent heterocyclic group derived from pyridine. The compound of formulaIis embodied by formulae II, III, etc., and hydrazone compound can be synthesized by using hydrazine represented by formula IV and a carbonyl compound represented by formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to a novel organic photoconductor comprising a hydrazone compound.
--------- The present invention relates to an electrophotographic photoreceptor having a photosensitive layer containing a monoelectric substance.

Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are 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 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. 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 photoconductive polymers including polyvinylcarbazole have been proposed, but are these polymers the aforementioned inorganic photoconductive polymers?

Although it is superior in film formability and lightness compared to other materials, it has been difficult to put it into practical use until now because it still has sufficient film formability. 7V due to environmental changes due to sensitivity and durability.

This is because they lack stability and are inferior to inorganic photoconductive materials. In addition, triarylpyrazoline compounds described in U.S. Patent No. 3,837,851 and the like, U.S. Pat.
hydrazone compounds described in Publication No. 50987, etc.
Low-molecular organic photoconductive materials such as 9-styrylanthracene compounds described in JP-A No. 51-94828 and JP-A-51-94829, and 4-chlorooxazole compounds described in JP-A-55-53278, etc. is proposed. By appropriately selecting the binder used, such low-molecular-weight organic round-groove material can overcome the film-forming defects that had been a problem in the field of organic photoconductive polymers. However, it cannot be said to be sufficient in terms of sensitivity.

An object of the present invention is to provide a new 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 material for use in a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer.

This object of the present invention is 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, RI and H are hydrogen atoms, aryl groups (e.g., phenyl, naphthyl, anthryl, etc.) or heterocyclic groups (e.g., pyridine, quinoline, carbazole, phenothiazine, sazine, etc.) A monovalent heterocyclic group derived from The above-mentioned aryl group and ascites ring group can have a substituent or an atom. The aryl group is a di-substituted amino group (e.g., dimethylamino group, diethylamino group,
dipropylamino group, dibutylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, di-substituted amino group, etc.), cyclic amino group (e.g., morpholino group, pyrrolidino group, piperidino group, etc.), alkoxy group (methoxy In addition, aryl groups and heterocyclic groups are substituted with alkyl groups (e.g., methyl, ethyl, n-propyl, ls
o-propyl group, n-butyl group, -butyl group, amyl group, t-'milhanawa, etc.), halogen atom (for example, chlorine atom, bromine atom, iodine atom, etc.) can also be substituted.

R8 and R4 are substituted or unsubstituted alkyl groups (
For example, methyl group, ethyl group, n-propyl group, 1
so-propyl group, n-butyl group, 5ea-butyl group,
t-butyl group, n-amyl group, t-amyl group, n-octyl method, 2-ethylhexyl group, t-octyl group, 2-
Hydroxyethyl group, 3-hydroxyethyl group, 2-chloroethyl group, 3-chloropropyl group, 2-methoxyethyl group, 3-methoxyethyl group), substituted or unsubstituted aralkyl group (e.g. benzyl group, phenethyl group) chlorobenzyl group, dichlorobenzyl group, methoxybenzyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc.), substituted or unsubstituted aryl group (e.g., phenyl group, tolyl group, xylyl group, diphenyl group,
Chlorophenyl group, dichlorophenyl group, trichlorophenyl group, methoxy 7! (c-nyl group, dimethoxyphenyl group, cyanophenyl group, α-su7tyl group, β-naphthyl group, etc.) or substituted or unsubstituted * ring element (e.g.
Pyridine, quinoline, carbazole, phenothiazine,
One example of heterocyclic disorder induced from phenoxazine etc.
Alkyl groups such as butyl, ethyl, propyl, butyl, and amyl groups, halogen atoms such as chlorine and bromine, alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy groups, and cyano groups are substituted. ).

R5 represents a divalent organic residue. Specific divalent organic residues include methylene W1, ethylene group, propylene, alkylene group such as butylene group, arylene group such as phenylene group, naphthylene group, biphenylene group, or pyridine, quinoline, carbazole, phenothiazine, phenoxazine, etc. Examples include divalent double purple ring groups derived from. In addition, for example, Hs These divalent organic residues include alkyl groups such as methyl, ethyl, propyl, butyl, amyl, and octyl groups, and halogens such as chlorine, bromine, and iodine atoms. Atom, mutoxy rattan, ethoxy group, propoxy group, alkoxy group such as butoxy group, nitro group, cyano group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dibenzylamino group, diphenylamino group, etc. Substitution It can also be substituted with an acylamino group such as an amino group, an acetylamino group, a propionylamino group, a butylamino group, a benzoylamino group, a trioylamino group, a hydroxy group, a carphocycl group, a sulfo group, and the like.

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

Compound example Mu -4 CH8 ■ C8-CM CH.

CH, -CH -19 Cloudy C,1~ ■-22 H-24 H-25 These hydrazone compounds represented by the general formula (]) are represented by the general formula (2) (where %'R3%Iζ and R3 are (has the same meaning as above) and a carbonyl compound represented by general formula (8)% (in which R8 and R2 have the same meaning as above). can do.

Next, the synthesis method for typical examples of hydrazone compounds used in the present invention will be shown below.

Synthesis example: Carbonyl compound 11.359 (0,06
4 mol), 100 ml of ethanol, and 100 fnA of acetic acid were mixed and stirred for 1 hour to react. After the reaction, the solution B was poured into water, and the resulting precipitate was dried separately.

6.33 t of yellow fever crystals at 150.0°C (yield: 30 t)
I got it.

Elemental analysis Molecular formula CnTLaNs calculated value
Analysis value C: 80.19% H: 7.05%: 7.06% N: 12.76%: 12.77% Other hydrazone compounds used in the present invention can be synthesized in the same manner.

As the electrophotographic photoreceptor containing the triazole compound represented by the general formula (1), any type of electrophotographic photoreceptor using an organic photoconductive substance can be applied, but preferred types include 1) electron-donating properties; A charge transfer complex formed by a combination of a substance and an electron-accepting substance.

2) Organic photoconductive material sensitized by adding a dye 0 3) Pigment dispersed in a hole matrix 04) Functionally separated into a charge generation layer and a charge transport layer 5) A composite consisting of a dye and a resin The main components are crystal complexes and organic photoconductors.

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, a hydrazone compound represented by general formula (1) is used as a charge transport material for the charge transport layer of the photoreceptor, which is functionally separated into two layers: a stain 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, we will discuss 4) type photoreceptor 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 either above or below the charge transport layer, but in Seiko photoreceptors of the type that are used repeatedly, it is mainly From the viewpoint of physical strength and, in some cases, chargeability, it is preferable to laminate a conductive layer, a charge generation layer, and a charge transport layer in this order. 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 can be formed by applying a solution of the hydrazo compound represented by the general formula (1) and a binder dissolved in a suitable solvent and drying the solution. preferable.

Examples of the binder used here include polysulfone, acrylic resin, methacrylic (θj resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, or repeating units of these resins). Examples include copolymer resins containing two or more of these, with polyester resins and polycarbonates being particularly preferred.Also, photoconductive resins that themselves have charge transport ability, such as poly-N-vinylcarbazole, are preferred. Polymers can also be used as binders.

The blending ratio of the binder and the charge transport compound is 1
00 parts by weight of the charge transport compound is preferably 10 to 500 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-Barr coach ink method,
Conventional methods such as spray coating, dip coating, bead coating, air knife coating, and curtain 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 halogenated fats such as methylene chloride, chloroform, and ethylene chloride. Examples include group 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, chlorinated paraffin, dilaurylthiopropionate. , 3,5-dinitrosalicylic acid, various fluorocarbons, silicone oil, silicone rubber or dibutylhydroxytoluene, phenolic compounds such as 2,2'methylene-bis-(6-t-hydroquinone, 2,5-di-t-octylhydroquinone) Examples include compounds.

The charge generating material used for the charge generating layer can be photosensitive, and preferred materials include selenium, selenium/tellurium, and selenium φ arsenic sulfide.

1 Inorganic substances such as amorphous silicon, pyrylium dyes, thiopyrylium dyes, triarylmethane dyes,
Thiazine dyes, cyanine dyes, phthalocyanine pigments, perylene pigments.

Examples include organic substances such as indigo pigments, thioindigo pigments, quinacridone pigments, squaric acid pigments, azo pigments, and polycyclic quinone pigments. The thickness of the charge generation layer is 5
μ or less, preferably 0.05 to 3 μ is desirable.

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 (8) Selenium-arsenic (4) Cadmium sulfide (6) 2 (22) (23) (24) (26) (27) (28) (30) co o
C (49) (50) (51) C1chi
C1I-(52) (53) (54) (56) (57) (58) Methyl squaric acid dye (59) Indigo dye (C11,478000) (60
) Thioindigo dye (C11, Mu78800) (61
) Copper phthalocyanine These pigments can be used alone or in combination of two or more. Further, the crystal form of these pigments may be α, β type, or (lt!), but β type is particularly preferred.

In the present invention, when forming a charge generation layer using the pigment fPFI described above, the pigment layer can be formed by vacuum evaporation, sputtering, glow discharge, or the like. Alternatively, a layer can be formed by dispersing the above-mentioned pigment in a suitable binder and applying this dispersion by a suitable coating method. In addition, the above-mentioned pigment layer can also be formed in a binder-free manner.

When dispersing the above-mentioned pigment, it can be dispersed by a known method using a ball mill, an attritor, etc., and the particle size can be set to 5 microns or less, preferably 2 microns or less, and optimally 0.5 microns or less. desirable. Also,
The above pigments are added to an amine solvent such as ethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, diethylaminepropylamine, N-aminoethylpiperazine, benzyldimethylamine, α-methylbenzyldimethylamine, tridimethylaminomethylphenol, etc. It can also be melted and applied. 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 5 microns or less,
Preferably, 0.01 micron to 1 micron is appropriate.

Binders for dispersing the above-mentioned compounds include polyvinyl buteral, polymethyl methacrylate, polyester, polyvinylidene chloride, polyamide, chlorinated rubber,
polyvinyltoluene, polystyrene, polyvinyl chloride,
ethylcellulose, polyvinylpyridine, styrene-maleic anhydride copolymers, etc.).

The proportion of such a binder in the charge generation layer is preferably 80% by weight or less, preferably 50% by weight or less of the total weight of 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. 6 can be used.

As a conductive layer, it is sufficient if it has conductivity.
Any type of conductive layer conventionally used may be used.

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

The thickness of the adhesive layer is 0.1 to 5 μ, preferably 0.5 to 3
μ is appropriate.

The hydrazone compound used in the present invention has hole transport properties, and when using a photoreceptor in which a conductive layer, a 'gf 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, charged, and 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 to neutralize the negative charge, resulting in a decrease in surface potential between the exposed area and the unexposed area. 〇An electrostatic contrast imager is generated. Various conventional developing methods can be used to visualize the image.

(4) With regard to photoreceptors other than the above types, the actual A'fl+ mode has been described in numerous patent publications and documents that have been proposed so far, so a detailed explanation 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 1 Casein ammonia aqueous solution (casein 1
1.2f, 28% ammonia water 17. 222 mt of water) was applied with a Mayer bar and dried, coating amount 1,0 f/r11
’ adhesive layer was formed.

Next, 2 tons of butyral resin (butyralization degree 63 mol %) was added to ethanol using a disazo pigment 52 having the following structure. After dispersing with a solution dissolved in 95 ml, the charge generating layer was coated on the adhesive layer to form a charge generation layer having a coating amount of 0.2 flrl after drying.

Next, the hydrazone compound's proboscis (H-1) 5'.

A solution prepared by dissolving 5f of poly-4,4'-dioxydiphenyl-2,2-probane carbonate (viscosity average molecular weight: 30,000) in 150 γ nL of dichloromethane was applied onto the charge generation layer and dried to obtain a coating amount of 107/back of charge. A transport layer was formed.

The electrophotographic photoreceptor thus prepared was statically charged with corona at 05 KV using Kawaguchi Electric Co., Ltd.'s Seiden Copying Paper Testing Equipment Model SP-428, and then charged at 10 KV in a dark place.
After holding it for a second, it was exposed to light at an illuminance of 5 tux and the charging characteristics were examined.

Initial potential Vo (V), potential retention rate for 10 seconds in the dark Rv (%, half-attenuation exposure amount El/2 (tuxsaee
) shows the charging characteristics of this photoreceptor.

■o: θ480■ Rv: 82chi El/2: 3.6 tux-8ec Example 2~
18 A 0-th order polyester resin (Byron 200, Toyobo ■) 5f on which the following pigment was vapor-deposited on a 100μ thick aluminum plate to form a charge generation layer with a thickness of 0.15μ.
A solution dissolved in 150 mt of hydrosizone thread compounds H-2 to H-185f-i dichloro y' tough was applied and dried on the charge generation layer to form a charge transport layer with a coating weight of 11 f/rrl. The charging characteristics of the electrophotographic photosensitive plate prepared in the same manner as in Example 1 were examined, and the results were summarized in Example 19. Selenium-tellurium (10'% tellurium) was vacuum deposited on an aluminum plate to a thickness of 0.8 μm A charge generation layer was formed.

Next, the same charge transport layer as used in Example 1 was applied and dried, and the coating amount was 11 f/n? And so.

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: e510V Rv: 82chi El/2: 2.7 tux-aec Example 2
0 Hydrazone compound (H-1) 5f used in Example 1 and poly1J-N-vinylcarbazole (molecular weight 300,000) 5F
β-type steel phthalocyanine 1.Of was added to a solution dissolved in dichloromethane 15 (hnl), and after dispersion, it was applied onto the casein layer of the aluminum plate provided with the casein layer used in Example 1, and the coating amount after drying was Let it be 10 t/d.

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 charge polarity is ■.

Vo: ■460v Rv: 79% El/2: , 16 tux-sec Example 21 A 0.2 tm thick molybdenum plate with a cleaned surface (
(substrate) was fixed at a predetermined position in a glow discharge deposition tank. Next, the inside of the tank was evacuated to a vacuum level of about 5×10″torr.

Thereafter, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150°C. After that, hydrogen gas and silane gas (15 volumes per hydrogen gas) were introduced into the tank, and the gas flow rate and the main pulp of the evaporation tank were adjusted to 0.5 torr.
It was stabilized. Next, a high frequency power of 5 Ml (z) was applied to the induction coil to generate a glow discharge inside the coil in the tank, resulting in an input power of 30 W. Under the above conditions, an amorphous silicon film was grown on the substrate to a film thickness of 2 μm. The glow discharge was stopped after maintaining the same conditions until the temperature reached 100°C.
After waiting for the hydrogen gas and silane gas to flow out, the pulp was closed and the inside of the tank was once lowered to below 10"torr, and the pressure was returned to atmospheric pressure, and the substrate was taken out. Next, Example 1 was deposited on top of this amorphous silicon layer. A charge transport layer was formed in the same manner.

The thus obtained photoreceptor was placed in a charging and exposure experimental apparatus, charged with corona at e6KV, and immediately irradiated with a light image. The light image was illuminated through a transmission type test chart using a tungsden lamp light source. Immediately thereafter, use a charged developer (
A good toner image was obtained on the photoreceptor surface by cascading the toner (containing toner and carrier) onto the photoreceptor surface.

Applicant Canon Co., Ltd. Copia 'A Kaunike Yr Daiyu ￥r person patent attorney Gi Marushima 313-

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) (In the formula, 'R1 and R represent a hydrogen atom, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. R1 and R6 are substituted or unsubstituted alkyl groups. , represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. R represents a divalent organic residue.)