JPS58111948A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To enhance initial acceptance potential, and to reduce dark decay, by adding an org. photoconductor contg. a hydrazone compd. CONSTITUTION:A photosensitive layer used in this invention represented by general formula in which Ar is an optionally substd. aromatic polycyclic hydrocarbon group; R1, R2, and R3 are alkyl, aralkyl, or aryl, each optionally substd.; and n is 0 or 1.

Description

[Detailed description of the invention] Book! ii Beak relates to electrophotographic photoreceptors, and more specifically relates to electrophotographic photoreceptors having a photosensitive layer containing a TFR-like organic photoconductive substance made of a hydrazone compound.0 Conventionally used in electrophotographic photoreceptors. Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are known as photoconductive materials. Although it has advantages such as the fact that there is little dissipation of electric charge or that the electric charge can be easily dissipated by light irradiation, it also has various disadvantages. For example, in a selenium-based photoreceptor, crystallization progresses rapidly due to factors such as forest, temperature, humidity, dirt, and pressure, and crystallization becomes difficult when the ambient temperature exceeds 40°C), resulting in a decrease in chargeability. Selenium-based photoreceptors and sulfurized cadmium-based photoreceptors have the disadvantage of causing white spots on images, while selenium-based photoreceptors and sulfide cadmium-based photoreceptors have the disadvantage of not being stable, good quality, and durable when used over time in high humidity environments. Good.Zinc oxide photoreceptors require sensitizing effects from sensitizing dyes such as rose bengal, but these sensitizing dyes cause charging deterioration due to corona charging and photobleaching due to exposure light, so long-term use is required. On the other hand, various organic photoconductive polymers including polyvinyl carbazole have been proposed; Despite the superiority of inorganic photoconductive materials in terms of film-forming properties and light weight, it has been difficult to put them into practical use until now because sufficient film-forming properties have not yet been obtained. U.S. Patent No. 4150987, U.S. Patent No. 42787
No. 47, German and German Complete Specification 'A2939483, British Il.
Low-molecular-weight organic photoconductive materials such as nine-human dicine compounds have been proposed in publications such as Kaikaimei No. 12034493 and European Patent Association No. 4IIA No. 13172. Such low-molecular organic photoconductive materials can overcome the shortcomings in film-forming properties of organic photoconductive polymers, which have been difficult to obtain at public expense, by appropriately selecting the binder used. However, it has drawbacks such as a low electrostatic potential and large dark decay, so if you keep it in the light for a certain period of time and then put it in the dark, you can In addition to the poor performance of restoring the original charging characteristics (photomemory properties), the object of the present invention is to overcome the above-mentioned disadvantage 4). It is another object of the present invention to provide a novel electrophotographic photoreceptor that eliminates the disadvantages of photoconductivity.Another object of the present invention is to provide a novel photoconductive material. Another object of the present invention is to provide an electrophotographic photoreceptor having improved initial potential error and dark decay.Another object of the present invention is to provide an electrophotographic photoreceptor having improved photomemory properties. .

Another object of the present invention is to provide a novel compound suitable for charge transport properties used in a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer. Achieved by an electrophotographic photoreceptor having a layer containing a hydrazone compound represented by formula (1). These aromatic rings with 0 representing a group, etc., include, for example, a chlorine atom, a bromine atom, etc.
Ge/atoms, alkyl groups such as methyl, ethyl, propyl, and butyl groups; oRl, - and B, which can be substituted with a di-substituted amino group such as a dibutylamino group, a dibutylamino group, a dibenzylamino group, a diphnicylat group, etc., represent an alkyl group (e.g., a methyl group, an ethyl group). , propyl group, butyl group, anru group, henzyl group, octyl group, etc.), substituted alkyl group (e.g., 2-chloroethyl group, 3-chloropropyl group, 2-hydroxyethyl group, 3-hydro dipropyl group, 2-methoxyethyl group, 3-methoxyprobyl group, 4-methodibutyl group, 2-ethoxyethyl group, 3-ethoxypropyl group, 4-ethoxybutyl group, etc.), aralkyl group (e.g. benzyl group, phenethyl group) , naphthylmethyl group, etc.), substituted aralkyl group, (
For example, methoxybenzyl group, dimethoxybenzyl group,
Methylbenzyl group, ethylbenzyl group, chlorobenzyl group, dichlorobenzyl group, diethylaminobenzyl group,
diethylaminobenzyl group, etc.), aryl group (phenyl group, naphthyl group, etc.) or substituted aryl group (tolyl group, medium silyl group, ethylphenyl group, diethylphenyl group, methoxyphenyl group, ethoxybutyl group, dimethylainophenyl group) group, diethylaminophenyl group, dipropylaminophenyl group, chlorophenyl group, dichlorophenyl group.
(6) Representative S is shown below.

t1υ
ttea place
Ripu OCR.

(31) These compounds may be used alone or in combination of 12 or more.
can be done.

Hydrazone Compound Co., Ltd. represented by these general formulas (1),
Hydrazine represented by the general formula % formula % (1 (in the formula, 8 and Bs are synonyms as above) and -M formula % formula % (in the formula, Mr, &, and - are # (It is a synonym of the term i.) It can be easily synthesized by a condensation reaction with the ketone shown in (n).

Next, the synthesis method for one representative compound among the hydrazone compounds used in the present invention will be shown.
1. Acetic acid 40 mj%N,N-diphenylhydrazine 2
．． 2g (0,012 mol)j? 2.0 g (0,012 mol) of the ketone represented by the structural formula
Time reaction friend. Next, after pouring water to form a precipitate, the precipitate was separated and washed repeatedly with water. .17g (yield 29-
) was obtained.

Elemental analysis bimolecule 2〇,i(,N.

Calculated value (Xun Experimental value (Xun) C87,718&76 H5,9S a 93 N 8L34 8.31 Other hydrazone compounds used in the present invention can be synthesized in the same manner.

The electrophotographic photoreceptor containing the hydrazone compound represented by the general formula (1) uses an organic photoconductive substance and can be applied to any type of electrophotographic photoreceptor, but the preferred type is l)electronic photoreceptor. A charge transfer complex is formed by combining a donating substance and an electron-accepting substance.

2) An organic photoconductor sensitized by adding a dye. 3) A pigment dispersed in a hole matrix. 4) A photoconductor that can be mechanically separated into a charge generation layer and a charge transport layer.

5) A eutectic unit consisting of a dye and a resin and an organic photoconductor as the main components 6) An organic or inorganic charge generating material fp in a charge transfer complex
There are nine types with I added, including 0, etc., of which 43) to 6) are desirable.

l! 4) type of photoreceptor, a hydrazone compound represented by the general formula (1) is used as a charge transport material for the charge transport layer of the photoreceptor, which is separated into the small charge generation layer and the charge transport layer 02 layer. In this case, the sensitivity of the photoreceptor is improved to 1% and the residual potential is low.In this case, the decrease in sensitivity upon repeated use and the increase in residual potential 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, and the charge generation layer and the charge transport layer O may be either the upper part or the lower part, but in the type of electrophotographic photoreceptor that is used repeatedly, it is mainly From the viewpoint of physical stiffness and, in some cases, from the perspective of incidental properties, it is desirable to laminate a conductive layer, a charge generation layer, and a charge transport layer. 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 prepared by combining a hydrazone compound represented by general formula (1) with a binder and a 1kS agent K [1
(by applying an equalized solution and drying). Examples of the binder include polysulfone, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, and phenol resin.

Examples include epoxy resins, polyester resins, alkyd resins-polycarbonates, polyurethanes, and copolymer resins containing two or more repeating units of these resins, 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.

What is the blending ratio of this binder and charge transport compound?

10 to 500 charge transport compounds per 100 parts of binder
It is preferable to set it as weight. The thickness Fi of this charge transport layer
The coating method used to provide a zero charge transport field of 2 to 100 microns, preferably 5 to 30 microns, is a blade coating method or a Mayer bar coating method.

Spray coating method, dip coating method.

Peed coating method, air knife coating method,
A conventional method such as a curtain coating method can be used.The solvent used in forming the charge transport layer of the present invention includes many useful organic solvents. , aromatic hydrocarbons I such as benzene, toluene, xylene, mesitylene, chlorobenzene, etc.
A@, ketones such as acetone and 2-butanone, halogenated/hydrogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride*, and cyclic or linear ethers I11 such as tetrahydrofuran and ethyl ether.
Alternatively, a mixed solvent of these can be used.

The charge transport layer of the present invention may contain various additives. Such additives include 1 diphenyl=diphenyl chloride, op-phenyl, P-terphenyl,
Diptyl phthalate.

Dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, silacrylthiopropionate, 3,5-dinitronalicylic acid, various fluorocarbons I1. Silicone oil, silicone rubber or dibutylhydroxytoluene, 2,2'-methylene-bis-(6
Examples include phenolic compounds such as -1-butyl-4-methylphenol), α-tocopherol, 2-1-octyl-5-chlorohydroquinone, and 2,5-octylhydroquinone.

As the charge generation material used for charge generation t-, any n material can be used as long as it absorbs light and generates charge carriers with extremely high efficiency, and preferred materials include selenium, selenium, etc. Inorganic substances such as tellurium, selenium, cadmium sulfide, and amorphous silicon, biryllium dyes, thiopyrylium dyes, triarylmethane dyes, thiazine dyes, cyanine dyes, 7-talocyanine octopus, and perylene pigment indigo. Examples include organic substances such as pigments such as pigments, thioindigo pigments, quinacrid pigments, squalic pigments, azo pigments, and polycyclic quinone pigments.

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 (3) Selenium-arsenic (4) Cadmium sulfide (5) ■ =H, to c2 (54) Methyl squarate dye - Indigo dye (0,1, /l678000)-thioindigo dye (0,1,A2B2O7)(6]) β
- type copper phthalocyanine These pigments can be used alone or in combination of two or more. It was. The crystalline form of these pigments is αm
, βm or any other value,
The electron photoreceptor of the present invention is preferably prepared by coating a charge generation layer containing the pigment described above on a suitable support, and forming a charge transport layer on the charge generation layer. It can be made by stacking layers and using nine structured photosensitive layers. This type of electrophotographic photoreceptor.

A medium+14 layer may be provided on one of the suitable supports, a charge generating layer containing the above-mentioned pigment may be formed thereon, and a charge transport layer may be formed thereon. This middle threshold value prevents the injection of free charges from the conductive support to the photosensitive layer when the photosensitive layer having a laminated structure is charged, and also allows the photosensitive layer to be integrally adhered and held to the conductive support. This intermediate 1, which acts as an adhesive layer, is made of gold II oxide such as aluminum oxide, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, Polyurethane, polyurethane resin.

Vinylidene chloride resin, vinyl chloride-vinyl acetate copolymer, casein, gelatin, polyvinyl alcohol, nitrocellulose, aqueous S-based ethylene-acrylic acid copolymer, etc. can be used. The thickness of this intermediate #lI or adhesive layer is suitably 0.1 to Ss, preferably 0.5 to 3.

First, a charge layer was provided on the charge transport layer. It can also have a laminated structure, and in this case, a suitable surface protective layer can be formed.The charge generation layer can be formed by vacuum deposition, sputtering, glow discharge insulation, etc. depending on the type of charge generation material used. It can be provided by

When coating, the charge generating material may be applied binder-free, as a resin dispersion, or as a homogeneous solution of the binder and the charge generating material.

In dispersing the pigment, known methods such as ball milling and attritor can be used, and it is desirable that the pigment particles be 5 μm or less, preferably 2 μm or less, and more preferably 0.5 μm or less.

The am cloth method, which can also be applied by dissolving the pigment in a carbon-based detergent such as ethylenediamine, is
Conventional methods such as ear bars, spray dipping etc. are used. □ The thickness of the charge generating film used in the present invention is 5 μm or less,
Preferably Fio, o11 miflon to it chron are suitable.

The ninth binder for dispersing the charge generating substance mentioned above includes polyvinyl butyral, polymethyl methacrylate,
Binders such as polyester, polyvinylidene chloride, polyamide, chlorinated rubber, polyvinyltoluene, polystyrene, polyvinyl chloride, ethylcellulose, polyvinylpyridine, styrene-maleic anhydride copolymer, etc. occupy the charge generating layer. The ratio should be 80% or less, preferably 50% or less of the embroidery weight for charge generation! J-ish.

(9) If necessary, the surface of the charge generation layer 1 can be polished to a mirror finish in order to uniformly inject carriers into the charge generation layer and the charge transport layer of the upper layer.

The 4-hydrazone compound used in the present invention has hole transport properties, and is used in the conductive layer, charge generation layer, and charge transport layer.
When using IllI type photoreceptor, charge transport - table mt
It needs to be negatively charged, and when it is charged and exposed to light, holes are generated in the charge generation layer in the transparent part, and holes are injected into the charge transport layer, neutralizing the negative charge over the center and surface, and increasing the surface potential. Attenuation occurs and electrostatic contrast occurs in relation to the unexposed area 01
Various conventional methods can be used to form an III image. Another example of the electrophotographic photoreceptor of the present invention is:
For example, the above-mentioned hydrazone compound is used as a charge-transporting substance, and the above-mentioned is added to a charge-transporting medium consisting of this and an insulating binder (the binder itself may be a charge-transporting substance such as poly-N'-vinylcarbazole). It is also possible to form a photosensitive IfA made by dispersing the application form of 1- in conductivity. The insulating binder and charge transport material used in this case are
No. 667, JP-A No. 47-30328 1M47-185
Those disclosed in each publication, No. 45, etc. can be used.

The support used in the electrophotographic photoreceptor of the present invention only needs to be imparted with electrical conductivity, and may be a conventionally used type of electrically conductive material. Specifically, aluminum.

Examples include metal sheets such as vanadium, molybdenum, chromium, cadmium, titanium, nickel, steel, fluoride, palladium, indium, tin, platinum, gold, stainless steel, and brass, and plastic sheets on which metals are vapor-deposited or laminated. .

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser printers.

It can also be widely used in electrophotographic applications such as CRT printers and electrophotographic plate making systems.

According to the present invention, compared to conventional electrophotographic photoreceptors using organic photoconductive materials, the electrophotographic photoreceptor of the present invention has the advantage of having a higher initial potential and lower dark decay. The photoreceptor has better photomemory properties than conventional ones and is useful for practical use.

Hereinafter, one embodiment of the present invention will be described.

Implementation file Ammonia aqueous solution of casein (casein 1
1.2ym28 air water l#.

Apply 222mj of water) with Mayer Par and dry, coating amount 1
Form an adhesive layer of 0 yawl.

Next, 5t of bisazo dye having the following structure.

tHs Butyral resin (degree of butyralization 63 mol-) 8# [After dispersing with a solution dissolved in ethanol 95mjK, II
After coating on the attached layer and drying, a charge generation layer with a coating amount of 0.2 pads was formed. Geo-chopsticksidiphenyl-2゜2'-propane carbonate (viscosity average molecular weight 30,000) 5pt dichloromethane y 150mJ was coated with Hirakashimaru liquid on the charge generation layer, dried, and the amount of 1 in 11 was
An electrophotographic photoreceptor was prepared by forming a charge transport H11 of 10#/Wr.

The initial potential, sensitivity, darkening *2, and photomemory properties of the electrophotographic photoreceptor thus prepared were measured using an electrostatic copying paper tester [Model 18P-408J manufactured by Kawaguchi Electric ■. At this time, corona charging is carried out to -5 volts using the stubbuck method, and the charging potential at this time is set as the initial potential (V.). Dark decay (Vl) is the charging potential (Is) held at 9 o'clock after corona charging for 5 seconds in a dark place, and 90 sensitivity is the exposure required for the potential (V, ) to decay after darkening. The photomemory property is measured by (CMA・lux seconds), and the photomemory property is evaluated by holding the photoreceptor under 1000 lux for 5 minutes and then determining the time t#I required to recover the original charging characteristics. did.

These results are shown in tube 1I11 Table 1: 590 volts Vo: -570 volts PM: 2 minutes IA wheel: 4.8 lux・sec Comparison 11-3 Hydrazone compound used in Example 1/% (1 ) in place of diethylaminobenzaldehy)'- of the following formula (A)
Using N,N-diphenylhydrazone, Tomohaka prepared a comparative amount of electrophotographic photoreceptor (Hiryo Sample 1) in the same manner. Also, Comparative Samples 2 and 3 were used in Example 1. The hydrazone compound 4 (instead of υ, the following formula (B) and (
(43) The charging characteristics of each comparative sample 1 to 3 were measured by the same method as in Example 111.The results are shown in Table 2.

1211 In place of the hydrazone compound (1) used in Example 1m*1, the hydrazone compounds listed in Table 3 below were used.% A9 An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 1. Then, its charging characteristics tIIl were determined. These results are also listed in Table 4.

! 31I Actual size 15 Hydrazone compound 4 (6) 5# and 5# of bisphenol A and copolyester of terephthalic acid and isophthalic acid (molar ratio of terephthalic acid and isophthalic acid 1:1) were dissolved in dichloromethane at 150 mjK. 1. Ott of β-type steel phthalocyanine was added to the solution, and after a few minutes, the nine casein layers used in the practical application were coated with Klk on the casein layer of an aluminum plate, and the coating amount after drying was set to 10 pads.

The charge measurement of the photoreceptor thus prepared was carried out in the same manner as in the actual film. The results are shown in No. 49. however,
Table 4 with charging polarity te Vo: +520 volts Vs+: +490 volts PM: 4 minutes N remaining: 12. A photoreceptor was prepared in exactly the same manner as in Example 115 using the hydrazo compound used in Comparative Example 2. The charging characteristics were investigated.The results are shown in tSS111.

SS table Ve: +340 volts Vm: +230 volts PM: 40 minutes]! Remaining: 3 fulx seconds $116 The following pigments were vacuum deposited on a 100 fi Arun plate with a thickness of 100.
After forming a charge generation layer with a thickness of 0.1571, polyester resin (Pylon 200 [4 spinning 1@) 5# and the exemplified hydracine compound (button S#t dichloromethane 1
50114 was applied onto the electroluminescence and dried.
A charge transport layer with a coating weight of 1197w1 was formed.

The charging characteristics of the electrophotographic photoreceptor thus prepared were examined in the same manner as in Example 1. The results are shown in Table II6.

Table 6 Ve: -560 volts V: -5 SO volts PM: 2 minutes IA axis: i4 lux/second ratio soft 115 Hydrazone compound used in implementation 9116, 4 (21)
Instead of using the hydrazone compound used in Comparative f#13, a photoreceptor was prepared in exactly the same manner as in Example f916, and then its charging 4I property was measured. The results are shown in Table 7. 01m7 Table Vo: -390 volts Vs: -280 volts PM: 2G minute E: 11. Flux Second Implementation 1117 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 applied and dried to give a coating amount of t 11 pad.

A good electrophotographic photosensitive plate prepared in this manner was examined for charging characteristics in the same manner as in Example 991. The results are shown in Section SaW.

81st N V: -590 volts Vs: -570 volts Pw: 2 minutes Mi axis: 3.3 lux seconds Example 18 A molybdenum plate (substrate) with a thickness of 0.2 mm and whose surface was cleaned.
[Fixed in a predetermined position in the glow discharge deposition tank.
Evacuate the K tank and b 11.5 X 1 G-' tOr
It's good to straighten the vacuum. After that, increase the input voltage of the heater to stabilize the molybdenum substrate temperature at 150℃, and then add water bulk gas and silane gas (15J amount - for hydrogen gas)
was introduced into the tank, and the gas flow rate and main pulp of the deposition tank were adjusted to stabilize the temperature at 0.5 torr K.9) Next, the induction coil K
A glow discharge tube is generated inside the coil in the tank by inputting the bird frequency power from the PM, and the input power is 30W. In the above case, an amorphous silicon film was grown on the substrate and the same conditions were maintained until the film thickness reached 2μ, and then the glow discharge was stopped.After that, the heating heater and high frequency power supply were turned off, and the substrate temperature was raised to 100℃. After waiting for the water volume gas and silane gas to flow out, the pulp is closed and the inside of the tank is temporarily reduced to IO-' torr.
After lowering the pressure to atmospheric pressure, the substrate 'fr was taken out.

Then, on top of this amorphous silicon layer, i#1I is applied.
The entire charge transport layer was formed in exactly the same manner as 11.

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. The light image was irradiated through a test chart of a transmission sample using a tungsten Lang light. Immediately thereafter, the photoreceptor surface was cascaded with a charged bulk agent (containing toner and carrier) onto the photoreceptor surface. An image was obtained.Example 19 Aqueous hydroxypropyl cellulose* was applied to a Tki plate and dried to form an adhesive layer with a coating weight of 0.6 #/g.

Next, add 150 mg of dichloromethane/5 t of di-N-vinylcarbazole and the aforementioned notified hydrazo/compound 4 (1
) of StS [2.4.7-1 linitrofluorenone 0
．． After dissolving 1#, 9 bisazo I used in real jl1M1
Section II 1.0# was added and after dispersion, the above adhesive layer hK was applied and dried to form a photosensitive layer with a coating weight of 11#/Wt.
I did the same thing. The results are shown in Table 9. However, the charging polarity was □: □■.

Table 9 Vo: +510 volts vs: +480 volts PM: 3 minutes Dedicated to: 13. flux second Patent applicant: Canon Co., Ltd.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor characterized by having a layer containing at least 1llt of a hydrazone compound represented by the following general formula (1). R, , R, and R represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aral group, and R represents a substituted or unsubstituted aral group. ＠0 indicates an aryl group. aFi
, O or 1. )