JPS604557A - Photosensitive material for electrophotography - Google Patents

Abstract

PURPOSE:To provide a photo-sensitive material for electrophotography, having excellent durability and stability against the variation of environment, capable of giving a stable image for a long period, and having a layer containing a hydrazone compound as a charge transfer compound. CONSTITUTION:The photo-sensitive material has a layer (charge transfer layer) preferably having a thickness of 5-30mum and containing one or more hydazone compounds of formula I [R1 and R2 are (substituted) alkyl, aralkyl, aryl or heterocyclic group; R3 is (substituted) alkyl, aralkyl, aryl or styryl; R3 is (substituted) aryl] (e.d. the compound of formula II or III) as the charge transfer compound. The charge transfer layer can be produced by compounding 10-500pts.wt. of the compound of formula I to 100pts.wt. of a binder (e.g. polyester resin, polycarbonate, etc.), dissolving the mixture in a solvent, and coating and drying the solution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a novel organic photoconductive substance comprising a hydrazone compound.

Prior Art Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known as photoconductive materials used in electrophotographic photoreceptors. Although it has advantages, for example, it can be charged to an appropriate potential in the dark, there is little charge dissipation in the dark, or the charge can be quickly dissipated by light irradiation VC, etc.
It has various drawbacks. For example, in selenium-based photoreceptors, crystallization easily progresses due to factors such as temperature, humidity, dust, and pressure. Especially when the ambient temperature exceeds 40°C, crystallization becomes significant, resulting in decreased charging performance and white spots on images. There are drawbacks such as the occurrence of Furthermore, selenium-based photoreceptors and cadmium sulfide-based photoreceptors have the disadvantage that stable sensitivity and durability cannot be obtained even when used over time under high humidity.

In addition, zinc oxide photoreceptors are typified by rose bengal.
However, the drawback of such sensitizing dyes is that they cannot provide stable 1jii images over a long period of time due to charging deterioration due to corona charging and photobleaching noise caused by exposure light. are doing.

On the other hand, various organic photoconductive polymers such as polyvinylcarbazole'tU have been proposed, but these polymers have superior film-forming properties, light weight, etc. to the aforementioned inorganic photoconductive materials. Despite its superiority in many aspects, it has been difficult to put it into practical use until now because it has not been possible to obtain sufficient film formation properties, sensitivity, durability, and environmental changes. This is because they are inferior to inorganic photoconductive materials in terms of stability. In addition, triarylpyrazoline compounds described in U.S. Patent No. 3,837,851 and the like, U.S. Pat.
Hydrazone compounds described in JP-A-50987, etc., JP-A-Sho, JP-A-51-94828, JP-A-51-9482
Low-molecular modified light-guiding materials have been proposed, such as the 9-styrylanthracene compound described in Japanese Patent Laid-open No. 55-55278 and the 4-chlorooxazole compound described in Japanese Patent Application Laid-open No. 55-55278. These low-molecular-weight organic photoconductive materials have been able to overcome the film-forming problems that had been a problem in the field of organic photoconductive polymers by carefully selecting the binder to be used. , cannot be said to be sufficient in terms of sensitivity.

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

Another object of the present invention is to provide a novel M-light barrel tolerant material.

Another object of the present invention is to create a photosensitive film that has a stacked structure of charge generation order and electrolyte feeding waste! The object of the present invention is to provide a compound suitable as a charge transport material used in electronic research.

Structure and Effects of the Invention The present invention relates to an electrophotographic photoreceptor characterized in that it contains at least one hydrazone compound represented by the following general formula +11.

General formula (1) In the formula, R1 and 1)2 are solid or unsubstituted alkyl groups (e.g., methyl group, ethyl JV group, n-propyl group, j, θ0-propyl group, n-butyl group, ec-butyl group, t-butyl group, n-amyl group, t-amyl group, n
-Octyl group, 2-ethylhexyl group, t-octyl group, 2-hydroxyethyl effivM% 3-hydroxypropyl hs, 2-chloroethyl group, 6-chloropropyl group, 2-methoxyethyl group, 6-medoxybrobyl group M), substituted or unsubstituted aralkyl groups (e.g.

benzyl group, phenethyl group, chlorobenzyl group, dichlorobenzyl group, methoxybenzyl group, α-naphthylmenal group, β-naphnalmethyl group), substituted or unsubstituted aryl group (for example, phenyl group, tolyl group, xylyl group, Diphenyl group, chlorophenyl group, dichlorophenyl group, trichlorophenyl group, methoxyphenyl group, dimethoxyphenyl group, cyanophenyl group, α-su7
thyl group, β-naphthyl group, etc.) - a substituted or unsubstituted complex group (e.g. derived from pyridine, quinoline, carbazole, phenothiazine, phenoxazine, etc.)
s-a It can also be substituted with halogen, methoxy group, ethoxy group, propoxy group, butoxy group, etc., cyano group, etc.).

R3 is a substituted or substituted alkyl group (eg, methyl group, ethyl group, n-propyl group).

-Propyl group, n-butyl group% 5ec-butyl group, t
-butyl group, n-amyl group, t-amylno.V%n-octyl group, 2-ethylhexyl 4, t-octyl group,
2-hydroxyethyl group, 6-hydroxypropyl group,
2-chloroethyl group, 5-chloropropyl group, 2-methoxyethyl group, 3-methoxypropyl 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.), aryl group (for example, phenyl group, naphthyl group, anthryl group, etc.), or steryl group, and this aryl group can have a substituent.

The aryl group is a substituted amino group (for example, N dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, dixylylamino group, etc.),
Cyclic amino groups (e.g. morpholino group, pyrrolidino group,
piperidino group) or alkoxy group (methoxy group,
It is preferable that one group is replaced by an ethoxy group, a propoxy group, a butoxy group, etc. In addition, aryl groups include alkyl groups (e.g., methyl, ethyl, n-
Propyl group, 160-propyl group, n-butyl group, t-
butyl group, amyl group, t-amyl group, etc.), halogen (
f! For example, chlorine, bromine, chloride, etc.) can also be substituted.

Ar Irj-s represents an aryl group (eg, phenyl group, naphthyl group, anthryl group, etc.). The above-mentioned aryl group can have a substituent.

Aryl groups include di-substituted amino groups (for example, dimethylamino group, diethylamine group, dipropylamino group, dibutylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, dixylylamino group, etc.), cyclic amine group ( For example, it is preferable that the compound is tetra-substituted with a morpholino group, pyrrolidino group, bilydino group, etc.) or an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.). In addition, aryl groups include alkyl groups (e.g., methyl group, ethyl group, n-propyl group, 18o-propyl group, n-butyl group, t-butyl group, amyl group, t-amyl group, etc.), halogen ( For example, it can also be substituted with chlorine (one odor, one odor, etc.).

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

Example compound 21'15 U21i5 -4 0H3 H3 H-9? L 02H502H5 2M5 U2M5 -17 -18 The hydrazone compound represented by the general formula (1) is a diketone represented by the general formula (21 (wherein R3 and Ar have the same meanings as above)). , can be synthesized by a conventional method using a hydrazine compound represented by the general formula (6) R1-NH2 (wherein R1 and R2 have the same meanings as above).

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

Synthesis example (synthesis of the hydrazone compound H-1) General formula (2)
in which Ar is 4-:) ethylaminophenyl group, R3
diketone 7.79F consisting of 4-methoxyphenyl group
('0.025 mol), 5.8+l (0.025 mol) of a hydrazine compound in which R1 is a phenyl group and R2 is a 1-naphthyl group in the general formula (6), and ethanol 100
d and 100ml of acetic acid were mixed and stirred for 1 hour to react.

After the reaction, pour this solution into water and a! P the precipitate that has been washed
Dry separately.

This solid content was recrystallized in MEK, with a melting point of 165-16
3.962 crystals (yield: 60%) were obtained at 8°C.

Cumulative Analysis Molecular Formula 035 H53N 302% Formula % Other hydrazone compounds used in the present invention can be synthesized in the same manner.

As the electrophotographic photoreceptor containing the hydrazone compound represented by the general formula (1), it can also be applied to an electrophotographic photoreceptor of the type n using an organic photoconductive substance, but the preferred types include 1) electron The entire stain transfer complex is formed by the combination of a donating substance and an electron-accepting substance.

2) An organic photoconductor sensitized by adding a dye.

5) Pigment dispersed in a hole matrix.

4) Functionally separated into a charge generation layer and a 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, 3) to 6) are preferable.

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 the photoreceptor, which is functionally separated into 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.

The layer structure is electrically conductive; a charge-generating layer is essential; a charge-transporting layer is essential; the charge-generating layer may be either above or below the charge-transporting layer; however, this type of electrophotography is used repeatedly; In the photoreceptor, 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, 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 formed by applying a solution in which the hydrazone compound represented by the general formula (υ) and the binding agent are dissolved in a suitable solvent and drying. That's a good thing.

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 other resins. Examples include copolymer resins containing two or more of the folding units, with polyester resins and polycarbonates being particularly preferred. Also, like poly-N-vinylcarbazole, it can be used as a whole binder for photoconductive polymers which themselves have transport capabilities.

The blending ratio of the binder and the charge transport compound is 1
00M parts of charge transport compound ii.

It is preferable that the weight is 500 to 500. The thickness of this charge transport layer is between 2 and 100 microns, preferably between 5 and 60 microns.゛In addition, the coating methods used when installing the entire charge transport layer include the blade coach ink method, Mayer coating method, spray coating method, dip coating method, jet coating method, air knife coating method, and curtain coating method. Ordinary methods such as can be used.

Further, the solvent used in forming the charge transport layer of the present invention includes all of a large number of 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 methylene chloride, chloroform, and ethylene chloride. Examples include halogenated aliphatic hydrocarbons, tetrahydrofuran, ethyl ether, linear ethers, and mixed solvents thereof.

The charge transport layer of the present invention can contain various additives. Darkening additives include diphenyl, dienyl, 0-terphenyl, P-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dilauryl thio. propionate, 6.5-dinitrosalicylic acid, various fluorocarbons, silicone oil, silicone rubber or dibutylhydroxytoluene, 2.2'methylene-bis-C6-t-phthyl-4-methylphenol)
, α-toco7 echol, 2-t-ocf-5-chlorohydroquinone, 2,5-di-t-octylhydroquinone, and other 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 an electric charge with extremely high efficiency. Preferred materials include selenium, Seren Tellurium, Seren Hi2, Vt
Inorganic substances such as cadmium chloride, amorphous silicon, biryllium dyes, thiopyrylium dyes, triarylmethane dyes, thiazine dyes, shea = 7 ffq dyes, phthalocyanine pigments, rylene pigments, indigo pigments, thioindigo pigments Examples include organic substances such as quinacridone pigments, sulfur, aric acid pigments, azo pigments, and polycyclic quinone pigments. The thickness of the charge generation layer is preferably 5 microns or less, preferably 0.05 to 3 microns.

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

(1) Amorphous silicon (2) Selenium-tellurium (6) Selenium-arsenic (4) Cadmium sulfide <INa) o+ (10) (11) (12) (16) (14) (66) (34) (66) ShiL UL (38) (49) (54) (56) (57) 02H5U2h15 (58) (60) (61) (62) Squaric acid methii dye (66) Indigo dye (o, engineering, A2B2O7) ( 64) Thioindigo dye (0, engineering, 78800) (65) Copper phthalocyanine These pigments can be used alone or in combination of two or more. Further, the crystal type of these pigments may be α, β type, or any other type, but β type is particularly preferred.

In the present invention, when forming the entire charge generation layer using the above-mentioned pigment, the above-mentioned pigment is applied by vacuum evaporation, sputtering,
/1 of the pigment by glow discharge etc. wo can be formed. Alternatively, the above-mentioned pigment can be dispersed in a suitable binder and the dispersion liquid can be applied by a suitable coating method to form the C layer. Alternatively, the entire layer of the pigment described above can be formed using a binder.

The gap in which the pigment is to be dispersed can be dispersed by a known method using a ball mill, an attritor, etc., and the particle size is set to 5 microns or less, preferably 2 microns or less, and optimally 0.5 microns or less. This is desirable. In addition, amine-based pigments such as total ethylenediamine, diethylenetriamine, tetraethylenepentamine, bank ethylenehexamine, diethylaminepropylamine, N-aminoethylpiperazine, benzyldimethylamine, α-methylbenzyldimethylamine, tridimethylaminomethylphenol, etc. 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 bar coating method, a spray coach ink method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method can be used.

The film JF4tcJ of the charge generation layer used in the present invention has a thickness of 5 microns or less, preferably 0.01 micron to 1 micron.

Examples of the ligating agent for dispersing the above-mentioned compounds include polyvinyl butyral, polymethyl methacrylate, polyester, polyvinylidene chloride, polyamide, chlorinated rubber, polyvinyltoluene, polystyrene, polyvinyl chloride, ethyl cellulose, polyhinylhyridine, Styrene
Mention may be made of maleic anhydride copolymers and the like.

The proportion of such a binder in the charge generation layer 14 is desirably 80% by weight or less, preferably 50% by weight or less of 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,
If necessary, the surface of the charge generation layer can be polished to a mirror finish.

As a mirror finishing method, for example, Fi JP-A No. 55-1553
No. 56 Publication No. 172: The method disclosed in f can be used.

As for the conductivity, it is sufficient that the layer is provided with conductivity, and any conventionally used conductive layer may be used.

As the material for the adhesive layer, conventional binders such as camoin, polyvinyl alcohol, nitrocellulose, hydroxymethylcellulose, and polyamide are used.

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

The hydrazone 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 charge transport layer are laminated in this order, the surface of the charge transport layer must be negatively charged. When charged and exposed to light, the holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, then reach the surface and neutralize the negative charge, causing a decrease in surface potential between the exposed area and the unexposed area. A contrast occurs during pregnancy.

For visualization, any conventional development method can be used.

Regarding photoconductors other than the (4) type, the actual aspects are described in numerous patent publications and documents proposed up to this iL, so a revised and thorough explanation will be omitted here.
．． The hydrazone compound of the present invention is also effective for these types of photoreceptors.

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 An ammonia aqueous solution of camoin (camoin 1) was placed on an aluminum plate.
1.2F, 28% ammonia water ir, water 222rnt)
Apply with Meyer Par, dry, and crush the coating 1. Q 97m
A second adhesive layer was formed.

Next, 5 parts of the disazo pigment having the following structure and 22 parts of butyral resin (degree of butyralization 66 mol%) were mixed with 95 parts of ethanol.
- After being dispersed with a solution dissolved in -, the charge generating layer was coated on the adhesive layer, and the coating amount after drying was 0.2 to form a total charge generating layer of 7 m2.

Next, the hydrazone compound (H-1) 5f, poly-4
, 4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 60θ00) 52 in dichloromethane 150m7! A solution dissolved in the above was applied onto the charge generation layer and dried to form a charge transport layer having a coating amount of 1097 m2.

The electrophotographic photoreceptor produced in this way was manufactured by Kawaguchi Electric Co., Ltd.
Seisaku t-m photo paper testing device II Model EIP -
428 using a static method (j5 KV), and after holding in a dark place for 10 seconds, the sample was exposed to light at an illuminance of 51 uX to examine the charging characteristics (i-).

The initial potential Vo (Vl), the potential retention heavy metal Rv□□□ for 10 seconds in the dark, and the half-attenuation exposure amount E (lux·BθC) indicate the RL% property of the present photoreceptor.

'v'o: e 460 (VI Rv; 88 (961 El: 4.01 uxjsec) Examples 2 to 18 The following pigment was deposited on a 100-micron-thick aluminum plate by nitrogen evaporation, and a charge was applied to a thickness of 0.15 microns. A generation layer was formed.

Next, polyester resin (Vylon 200, Toyobo Co., Ltd.) 52 and the above-mentioned hydrazone compounds H-2 to H-1
A solution of 85f 'e dissolved in 150 ml of dichloromethane was applied onto the charge generating layer and dried, resulting in a coating amount of 11 l/m.
2 charge transport layers were formed.

The electrophotographic photoreceptor thus prepared was subjected to charging characteristics Wω in the same manner as in Example 1, and the results are shown in Table 1.

Table 1. 74 ,2 11H-11460834,4 12Tl-12510865,2 16n-113470884,2 14H-14480864,0 15H-15460884,2 16H-16480854・6 17 H-17480895,0 18H-184608 25,4 Example 19 On an aluminum plate Selenium-tellurium (10% tellurium) was deposited in a full vacuum to form a charge generation layer with a thickness of 0.8 microns.

Next, the same charge transport layer as used in Example 1 was coated and dried to give a coating weight of 11 r/m<2>.

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: e500V RV: B6C'fJ E duration: 4.41uxjsec Example 20 Hydrazone compound (H-1) used in Example 1 5? andbo IJ-N-vinyl carno (sol (molecular lid 300,000) 5
After dissolving 1.0v of β-type copper phthalocyanine in a dichloromethane 150ml 1K bath solution, casein i used in Example 1 (camoin on an aluminum plate with ! 'aT) was added.
-, and the total coating amount after drying was 1017 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.

Rv: A% Example 21 0.2M thick molybdenum plate (substrate) with a clean surface
was fixed at a predetermined position in the glow discharge evaporation N tank. Next, the tank was completely evacuated to a vacuum level of approximately 5×10 −6 torr.

Thereafter, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150°C. Thereafter, water wing gas and silane gas (15% by volume relative to hydrogen gas) were introduced into the bone, and the gas flow rate and the main valve of the deposition tank were adjusted to stabilize the pressure at 0.5 torr. Next, 5 MHz high frequency power was fully applied to the induction coil to generate a glow discharge inside the coil in the tank.
The input voltage was 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 heater and high frequency power supply, wait for the substrate moisture to reach 100°C, close the hydrogen gas and silane gas outflow valves, and once the temperature inside the tank is lower than 10-6 torr, return to atmospheric pressure and remove the substrate. I took it out. Next, a charge transport layer was formed on this amorphous silicon layer in the same manner as in Example 1.

The photoreceptor thus prepared for 40 days was charged and placed in an exposure apparatus, and was corona charged at M and Lθ of 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, an e-chargeable developer (including toner and carrier) was cascaded over the entire surface of the photoreceptor to obtain a good toner image on the surface of the photoreceptor.

Patent applicant: Canon Co., Ltd. Represented by Patent Attorney Sou Karino

Claims (1)

[Claims] (1) An electrophotographic photoreceptor having a layer t- containing at least one compound represented by the following general formula (13). General formula (1) (wherein R1 and R2 are substituted or It represents an unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. R3 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted represents an aralkyl group, a substituted or unsubstituted aryl group, or a styryl group. Ar represents a substituted or unsubstituted aryl group.