JPS61175644A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To form the laminate type electrophotographic sensitive body having a high sensitivity and a very small residual potential after an endurance test by forming the layer contg. a specific polycyclic quinoline type pigment as a charge generating layer, and the layer contg. a specific hydrazone type compd. as a charge transfer layer respectively. CONSTITUTION:The charge generating layer is composed of the layer contg. the polycyclic quinoline type pigment shown by formula (I), and the charge transfer layer composes of the layer contg. the hydrazone compd. shown by formula (II). The binder used in forming the charge generating layer with coating is selected from a broad range of an insulating resin, and preferably is the insulating resin such as polyvinyl butyral. The compounding amount of the resin contd. in the charge generating layer is preferably <=40wt%. Said resin has the formula wherein R1, R2, R3 and R4 are each a hydrogen atom or a halogen atom, R5 is a hydrogen atom, an alkyl or an alkoxy group, R6 and R7 may be substd. and are each an alkyl, an aralkyl or a phenyl group, R6 and R7 together with a nitrogen atom can form a 5-6 membered ring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides organic light 41! Regarding the body, especially transporting cargo,・J
The present invention relates to an electrophotographic photoreceptor having a charge generation layer.

[Conventional technology]

Electrophotographic photoreceptors using inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide as one photoreceptor have been known so far.

On the other hand, many organic photoconductors have been developed since it was discovered that certain organic compounds exhibit optical properties. For example, ``)-N-vinylcarbazole, ?livinylanthracene and other light-guiding polymers, carbazole,
Low-molecular photoconductors such as anthracene, pyrazolines, diazoles, hydrazones, and polyarylalkane, phthalocyanine pigments, azo pigments, cyanine dyes, polycyclic quinone pigments, perylene pigments, indigo dyes, and thioinsophores. Organic pigments and dyes such as dyes or square methine dyes are known. Additionally, organic pigments and dyes that exhibit photoconductivity are easier to develop than inorganic materials, and furthermore, the range of possibilities for selecting compounds that exhibit photoconductivity in an appropriate wavelength range has been expanded. Many original tetraelectric pigments and dyes have been proposed.

For example, US Pat. No. 4,123,270, US Pat. No. 42,476
No. 14, No. 1 No. 4251613, No. 4251614
No. 4256821, No. 4260j572,
Same No. 4268596, Same No. 4278747, Same No. 4
No. 293628 specification, etc., Hirokosha X photoreceptor using a disazo pigment showing a light 4 electric pole with 7 as a charge generating substance in a photosensitive layer functionally separated into a ζ charge generation layer and a charge transport layer in the square indicated by y4. is known.

Electrophotographic photoreceptors using such organic photoconductors can be produced by coating by appropriately selecting a binder, making it possible to provide photoreceptors with extremely high productivity and low cost. This has the advantage that the sensitive wavelength range can be freely controlled.

The layer-type photoreceptor obtained by laminating a charge-generating layer mainly composed of a charge-transporting material and a charge-generating material has a higher sensitivity than other single-layer type photoreceptors and has a higher sensitivity and residual resistance after durability tests. Although it is advantageous in terms of increasing the potential, it is still not at a sufficient level.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and provide a laminated electrophotographic photoreceptor with high sensitivity and low residual potential even after a durability test.

The present invention aims to achieve the above-mentioned object by forming a t'C charge-generating material on a flexible support, a laminate having two layers: a charge-generating layer having f+ as a raw fraction and a charge-transporting layer having a charge-transporting layer as a main base. This is achieved by using a specific polycyclic quinone pigment in the charge generation layer and having a charge transporting JJK specific hydrazone compound in the electrophotographic photoreceptor.

[Means for solving problems]

The present invention provides a multi-layered electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a four-electrode support. The charge transport layer is separated from the layer containing the pigment based on the general formula ω) (where RI HFE2 g R5 and R4 are water $1.
atom or halodane atom, R5 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R6 and R7 represent items 5 to 6, together with an alkyl group, an aralkyl group, a phenyl group, or an N atom that may have a substituent. The forming residues are shown. ) The electrophotographic photoreceptor is characterized in that it comprises a layer containing a hydrazone compound represented by:

The present invention will be explained in detail below.

In the 8-layer electrophotographic body of the present invention, the charge generation layer contains as much charge generation material as possible in order to obtain sufficient absorbance, and the generated charge carriers t - charge efficiently. To inject into the transport j-, thin Jm, e.g. 1
A thin film layer having a thickness of 0 micron or less, preferably 0.01 micron to 1 micron is desirable. This means that most of the incident light is absorbed by the red charge generator, generating a large number of charge carriers, and that the charge carriers generated in the field are lost through recombination and capture (depletion). This is due to the need to inject into the charge transport layer without activation.

The charge generating material used in the present invention is a polynomial quinone pigment represented by the formula (R).

The charge-generating layer can be formed by coating the above-mentioned pigments and, if necessary, a transport material on a substrate with an appropriate binder (or without a binder), and can also be formed by depositing the deposited film on a vacuum evaporator. can be obtained by forming K.

The binder that can be used to form the charge generating layer by coating can be selected from a wide variety of insulating resins, as well as organic photoconductive polymers such as poly-N-vinylcarpanole, polyvinylanthra7ane, and polyvinylpyrene. can. Preferably, polyvinylbutytool, polyarylate (condensation polymer of bisphenol A and heptalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin,
Examples include insulating resins such as polyamide, polyvinylpyrinone, heptacosic resin, phrethane resin, nixy resin, casein, talyvinyl alcohol, and polyvinylpyrrolidone. The resin contained in the charge generation layer is 8
A value of 0xf or less, preferably 40xf or less is suitable.

The solvent for dissolving these resins varies depending on the type of resin, and it is preferable to select a solvent that does not dissolve the charge-generating layer or the subbing layer. Specific organic solvents include alcohols such as methanol, ethanol, and isoglopanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, amides such as fJ, N, N-dimethylformamide, N, N-tumethylacetamide, and dimethyl sulfoxide. sulfoxides such as tetrahydrofuran, soybean paste, ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aliphatic halogens such as chloroform, methylene chloride, nochloroethylene, carbon tetrachloride, trichlorethylene, etc. Hydrocarbons or aromatic compounds such as benzene, toluene, xylene, ligroin, monochlorobenzene, and nochlorobenzenato can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as an i-earper coating method, a blade coating method, a roller coach ink method, or a curtain coating method. For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying can be carried out at 30° C. to 200° C. for a period of 5 minutes to 2 hours, either stationary or with air blowing.

The charge transport layer is the above-mentioned charge generation layer and 1! It has the function of being able to receive and take charge carriers injected from the charge generation layer in the presence of an electric field, and to transport these charge carriers to the surface. In this case, this 11 charge transport layer, g, may be laminated on the charge generation layer or may be laminated below it. That is,
This is desirable because the surface of the photoreceptor shows little deterioration during VJ4 reverse durability, and furthermore, by selecting a binder in the charge transport layer, a better surface of the photoreceptor can be formed.

In the charge transport layer! The substance that transports charge carriers (hereinafter simply referred to as charge transport substance) is preferably substantially insensitive to the electromagnetic wave wavelength range to which the five charge generation layers are sensitive. The magnetic waves j mentioned here include γ-rays, X-rays,
Includes a broad definition of "optical organ" that includes far-infrared rays. When the former sensitive band length region of the charge transport layer coincides with or overlaps that of the H. fungi, the f
c'ff! , the load carriers capture each other, resulting in a decrease in sensitivity.

The charge transport material used in the present invention is a hydrazone compound represented by the general formula ().

(In the formula, R,, R2, R, and R4 are water X atoms or)
R5 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R6 and R7 form a 5- to 6-membered ring together with an alkyl group, an aralkyl group, a phenyl group, or an N&son group which may have a substituent. The residues shown are shown below. ) This human 9-razone compound is a charge transporting substance that has all of the above-mentioned pO@':i 1'P) and has excellent properties, particularly in terms of sensitivity and durability.

Typical hydrazicine compounds represented by the general formula (1) used in the present invention are illustrated in Table 1.

Table 1 In addition, in the invention, it is possible to add the above-mentioned hydrazone compound etc. used in the charge transport layer to the charge generation layer.
The sensitizing effect becomes even more remarkable @ When a charge transport material'f is added to the charge generation layer, the hydrazone compound is 10 times or less (weight ratio) of the charge generation material.
Preferably, 0.01 to 1 times (weight ratio) is appropriate from the viewpoint of high sensitivity, low residual center position, and repeatability stability.

To form a charge transport 7ji containing a hydrazone compound, a film bottom is formed by selecting an appropriate binder. What resins can be used as binders, such as acrylic resin? Reacrylate 1.41J ester, polycargonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, insulating resin such as chlorinated rubber, or polyN- Organic photoconductive polymers such as pinylcarnozole, -rivinylanthra7ane, -rivinylbirene and the like may be mentioned.

Since the charge transport layer has a limit in its ability to transport charge carriers, Vc1! It is not possible to increase the X thickness.

Typically it is 5 microns to 30 microns, with a preferred range of 8 microns to 20 microns. When forming the charge transport layer by coating, any suitable coating method described above can be used.

A photosensitive layer consisting of such a laminated structure of a charge generation layer and a charge transport layer is provided on a substrate having a tetraelectric layer, that is, a conductive support. Examples of the substrate having a conductive layer include those whose substrate itself is conductive, such as aluminum, aluminum alloy, copper, and zinc.

Stainless steel, Hananocum, molybdenum, chromium, titanium, nickel, inzoum, gold, platinum, etc. can be used, and in addition, aluminum, aluminum alloys, inzoum oxide, tin oxide, insoum oxide alloy, etc. can be used.
Cicada 1 coated by empty deposition method: A substrate in which the plastic to be grown (e.g., carbon plaque, silver particles, etc.) is coated on the plastic together with a suitable binder,
It is possible to use a material in which conductive particles are embedded in plastic or paper, a glass material having a Δ conductive polymer, or the like.

It is also possible to provide a barrier function and an adhesive layer between the layers. The sublayer is
casein, polyvinyl alcohol, nitrocellulose,
Ethylene-acrylic acid copolymer, polyvinyl butyral, phenolic resin, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), ? urethane, gelatin, acid r
It can be formed by Hyaluminum etc.

The H thickness of the undercoat layer is suitably 0.1 micron to 40 micron, preferably 0.1 micron to 3 micron.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, and the charge transport material in the charge transport layer is composed of a particle transport material, the surface of the charge transport layer must be positively charged. When exposed to light after being charged, the exposed part is injected with free 9' silica through charge transport in the charge generation layer.
After that, it reaches the surface and neutralizes the positive charges, resulting in attenuation of the surface potential and an electrostatic contrast between it and the unexposed area.

The silence created in this way! By developing the jL high-resolution image with a load-forming toner, an l-j'5T visual image is obtained. this? It can be directly fixed, or the toner image can be transferred to paper or glass film, developed, and fixed.

Alternatively, a method may be used in which the still image on the photoreceptor is transferred, developed, and fixed onto the edge layer of transfer paper. The developer dd, dust II method, and fixing method may be any known method or known methods, and are not limited to specific methods.

On the other hand, when the charge transport material consists of a hole transport material, it is necessary to negatively charge the charge transport/J surface.
When exposed to light, the holes generated in the charge generation M are injected into the load transport IJ in the Et light area, and are then moved to the surface to neutralize the negative charges, causing the surface potential to attenuate and creating an electrostatic charge between it and the unexposed area. Contrast occurs.

In current acupuncture, it is necessary to use a positively charged toner, contrary to the case where a nucleo transporter is used.

According to the present invention, (the secondary photographic photoconductor may deteriorate due to ultraviolet rays, ozone, etc., be contaminated by oil, etc., become rusty due to metal chips, etc.), and the photoconductor may be damaged by photoconductor abutting members such as developing members, transfer members, cleaning members, etc. A protective layer may be further provided on the charge generation layer or charge transport I in order to prevent scratches and abrasion of the surface. It is desirable that the ratio is 10 Ω or more.

The protective layer used in the present invention is made of polyvinyl butyral, polyester, polygenerate, acrylic resin, methacrylic resin, nylon, polyimide, polyarylate, polyurethane, styrene-butanoene cobolinmer, styrene-acrylic acid copolymer, styrene-acrylonitrile. It can be formed by coating a resin ft such as a copolymer, a liquid f: dissolved in an appropriate organic solvent, on the photosensitive layer, and drying.

Additionally, additives such as ultraviolet absorbers can be added to the resin liquid. At this time, the film thickness of the δ-retaining layer is generally 0.05~
20 microns, preferably in the range of 0.2 to 5 microns per row.

Hereinafter, the present invention will be explained according to actual examples.

Example Ammonia water g of casein on an aluminum cylinder
ic casein 11.2P, 28% ammonia water 1y-1
222d) of water was applied by a coating method and dried to form a full-length undercoat layer with a thickness of 7rm''.

Next, a charge generating material 11 (: 1 part,
Butyral! Seal sealant (S-LEC BM-2:, d water chemistry (
(Company) 1 part by weight and 30 parts by weight of isopropyl alcohol were dispersed for 4 hours using a 2-lumyl dispersion rock. This layer was first formed and coated using the above-mentioned immersion coating method, followed by drying to form an alpha charge generation layer. The film thickness at this time was 0.3μ. Next, the compound of Table 1 & (1) (P-diethylaminopenzaldehy)"-N-phenyl-α-nafdelhydrason 1:ilr part, polysulfone tree N (P 1700 manufactured by Zion Carbide Co., Ltd.)
1 part by weight and 61 parts of monochlorobenzene were mixed and stirred by a stirrer.

This liquid was applied onto the charge generation layer by dip coating and dried to form a charge transport layer. At this time, the film 4 is 1
It was 2μ.

Corona discharge of -5k'/ was applied to the photoreceptor thus prepared. The surface potential at this time was measured (at ?7J period).
O) o Furthermore, the surface potential of this photoreceptor was measured after leaving it in the dark for 5 seconds (t, t) (dark decay Vs).

Sensitivity was evaluated by measuring the exposure 1 k (E 1/2 1 u engineering·gee) required to make the t position V after dark decay into a plate shape of 14.

These results were as follows.

V6: -635 Melt V: -620 Melt E1/2: 4.91ux-*me Examples 2 to 1
0 A photoreceptor f was prepared in exactly the same manner as in Example 1, except that the compounds shown in Table 1 were used in place of the compound (1) used in Example 1, and the photoreceptor f was prepared using the same method as in Example 1. Characteristics were measured. These results are shown in Table 2.

Table 2 2 2 625 610
5.03 3 630
610 5.54 4
620 605 5.35
5 620 600
5.16 6 645
630 6.07 7
650 630 6.28
8 630 615
5.39 9 635 6
20 5.610 10 6
35 615 5.7 Comparative Examples 1 to 6 Photoreceptors were prepared in exactly the same manner except that the charge transport materials shown in Table 3 were used in place of the hydrazone compound used in Example 1. That emperor tq! Table 4 shows the f properties.

Table 3 vJ Ri2 [) Table 4 1 1 6005707.2 2 2 5955706.9 3 3 6055857.4 4 4 6155908.1 5 5 5805557.7 6 6 5905607.5 It is clear from the results of Examples and Comparative Examples As can be seen, the laminated photoreceptor of the present invention provides a gi body with extremely high sensitivity compared to the photoreceptors x1 to x'6 of the comparative examples. Furthermore, using the photoconductors of Examples 1 to 3 using a copying machine (NP-150Z: manufactured by Canon Inc.), image production was repeated 20,000 times. As a result, good quality images were obtained for all photoreceptors even after repeating 20,000 times. As a result, it can be seen that the photoreceptor of the present invention has extremely excellent fire resistance.

〔Effect of the invention〕

As is clear from the above, the present invention uses a specific multifunctional quinone pigment as a charge generation material in the charge generation layer and a specific hydrazone compound in the charge transport layer, thereby achieving extremely high sensitivity compared to conventional ones. This made it possible to provide a high-efficiency, J-type photographic photoreceptor.

Acting Patent Attorney Johei Yamashita

Claims (2)

[Claims] (1) In a laminated photographic photoreceptor in which a charge generation layer and a charge transport layer are provided on a conductive support, the charge generation layer has the formula (
I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼It consists of a layer containing a polycyclic quinone pigment represented by (I), and the charge transport layer is the general formula (II).▲There are mathematical formulas, chemical formulas, tables, etc.▼(II ) (In the formula, R_1, R_2, R_3 and R_4 represent a hydrogen atom or a halogen atom, R_5 represents a hydrogen atom, an alkyl group or an alkoxy group, and R_6 and R_7 represent an alkyl group or aralkyl group which may have a substituent. 1. An electrophotographic photoreceptor comprising a layer containing a hydrazone compound represented by the following formula. (2) The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer contains a hydrazone compound represented by formula (II).