JPS60256145A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance printing resistance, to prevent filming, and to reduce abrasion of a photosensitive boby by incorporating a specified hydrazone compd. and a phthalocyanine type photoconductor powder in the photosensitive layer so as to render the content of the hydrazone compd. lower as it approaches the surface. CONSTITUTION:The photosensitive layer contains the hydrazone compd. (HZN) represented by the formula (R1 is H, alkyl, or aryl; R2, R3 are each alkyl, aralkyl, aryl, or a condensed polycyclic group, and both may form a ring together with each other; A is an aromatic hydrocarbon group or heterocyclic group; and (n) is 1 or 2), in a concn. distribution lowering toward the surface of the photosensitive layer, and a phthaloxyanine type photoconductor powder. The use of the (HZN) compd. in a certain concn. or higher allows electrostatic charge transfer amt. to depend on the total concn. of the photosensitive layer, irrespective of the concn. difference, if any, between th surface layer and the inner layer. The reduction of the HZN conc. near the surface can lower induction effect, and decrease of printing resistance, and it can enhance sensitivity and improve repetition characteristics.

Description

[Detailed description of the invention]

Industrial Application Field The present invention relates to an electrophotographic photoreceptor, in particular, to an electrophotographic photoreceptor, in which a photoconductive material is formed on a substrate, and a photosensitive layer is formed by dispersing particles in a binder made of an insulating polymeric material. The present invention relates to an electrophotographic photoreceptor. Prior art In recent years, for example, Japanese Patent Application Laid-Open No. 1-38543, Japanese Patent Application Laid-open No. 95852-1982, and Japanese Patent Application Laid-Open No. 53-64040
No. 7, JP-A No. 53-83744, etc.
Photoreceptors using talocyanine-based photoconductive materials have been proposed. This type of photoreceptor does not have the hygiene problems seen with inorganic photoconductive materials such as selenium and cadmium sulfide, and is known to exhibit high sensitivity to long wavelength light such as semiconductor lasers. . However, photoreceptors in which this type of 7-thalocyanine-based photoconductive powder is dispersed in a binder resin have the disadvantage of exhibiting the so-called inglucitane effect, in which a tramp occurs and a time lag occurs from exposure to potential decay. be. As a method for reducing this induction effect and improving sensitivity, the present inventor proposed a method for reducing this induction effect and improving the sensitivity by applying
+), we proposed a method of adding a large amount of hydrazone compound. However, when a large amount of the hydrazone compound was added, the hydrazone compound acted as a plasticizer, resulting in low coating film hardness and poor printing durability. Purpose of the Invention The present invention aims to improve the above-mentioned drawbacks of the photoreceptor containing the hydracine compound described in 1-1. We present an electrophotographic photoreceptor that prevents filming and reduces abrasion on the surface of the photoreceptor. Structure of the Invention The present invention provides a photosensitive layer formed on a substrate 1- by dispersing a hydrazone compound represented by the general formula fil and a 7 talocyanine-based conductive material powder in a grinding resin. In a photographic photoreceptor, hydrazone compound content 1
I1. A photosensitive device characterized in that the amount of pores is so small that it reaches the surface of the photosensitive layer: I1. R. 1/A-+-C=N-N) n III I\l. In formula 1, R1 is hydrogen, an alkyl group or an aryl group, R
2 and 1<, are an alkyl group, an aralkyl group, an aryl group which may have a substituent, a fused polycyclic group which may have a substituent, and A is an aromatic carbonized group which may have a substituent. Hydrogen group or yf aromatic heterocyclic group and 11 represent a numerical value of 1 or 2. l? 21; and R1 may be combined to form a ring. Provide 1. In the present invention, the amount of the hydrazone compound is reduced toward the surface of the photosensitive layer. To be more precise, the amount of the hydrazone compound as well as the amount of the lysocyanine-based electrically conductive material powder contained should be reduced. This increases printing durability +11. On the way! I'm sorry. Generally, a photoreceptor using a phthalocyanine-based conductor is irradiated with visible light, but since absorption of visible light occurs on the surface of the photosensitive layer, the amount of photoconductor 3 is adjusted closer to the surface of the photosensitive layer. It was thought that it was not desirable to reduce the number of Furthermore, when a hydrazone compound or the like is used as a charge transport agent, if there is variation in concentration between the surface layer and the inner layer, the amount of charge transport is predicted to be controlled by the lower limit concentration, and hydrazone It has been believed that it is preferable for the total amount of the compound to be uniformly dispersed in the photosensitive layer. However, in the research conducted by the present inventors, 1-
When a hydrazone compound is present in the photosensitive layer, the amount of charge transport depends on the total concentration of the photosensitive layer, and even if there is a difference in concentration between the surface layer and the inner layer, the amount of charge transport is substantially the same! - It was found that there was almost no effect. The hydrazone compound used in the present invention has the general formula % (wherein R is hydrogen, an alkyl group, especially a methyl group or an aryl group, especially a phenyl group, R2 and 4- and R are an alkyl group, an aralkyl group or an aryl group which may have a substituent, a fused polycyclic group which may have a substituent, 11 is the number 1 or 2, and )\ may have a substituent) Representing an aromatic hydrocarbon group or an aromatic heterocyclic group, 1°R2 and 1< may form a ring via both. 1 Representative examples of hydrazone compounds include C and II. In the present invention, the concentration of the hydrazone compound decreases as it approaches the surface layer.The concentration of the hydrazone compound in the surface layer is 8 to 100 parts by weight of the binder resin. It is in the range of 1()% by weight or more, preferably 20-50% by weight.If it is less than 10% by weight, the amount of charge transport decreases markedly.The average concentration of the hydrazone compound is in the binder resin. ]00 parts by weight, IS・~2 +1 +)
It is at least 20% by weight, preferably 20 to 150% by weight. The hydrazone compound in the surface layer of the photoreceptor is dispersed by oxygen and light in the air, and its effectiveness gradually decreases.It seems preferable to keep the concentration of the surface layer high, but in reality the surface layer There is no problem in practical use because a new layer appears after being scraped off slightly. As the phthalocyanine photoconductive material used in the present invention, any of the phthalocyanine and its derivatives which are known per se can be used. Talocyanine, gallium 7 thalocyanine, cadmium 7 thalocyanine, indium 7 thalocyanine, lanthanum 7 thalocyanine, samarium phthalocyanine, europium phthalocyanine, nosprosium phthalocyanine, intrium 7 thalocyanine, ruthenium phthalocyanine, copper 7 thalocyanine, vananium 7 thalocyanine , tin 7-thalocyanine, titanium 7-thalocyanine, lead phthalocyanine, thorium phthalocyanine, uranium 7-thalocyanine, man-7 thalocyanine, iron phthalocyanine,
These include cobalt-7-thalocyanine, niakelphthalocyanine, ronoumphthalocyanine, paranrum-7-thalocyanine, and bananol-7-thalocyanine. Furthermore, the central nucleus of the phthalocyanine may not be a metal atom, but may be a metal halide having a valence of 1,3 or more -1-. In addition, metal-free 7-thalocyanine compounds such as copper-4-7 mino-7-thalocyanine, iron polyhalophthalocyanine, cobalt-hekigaphenylphthalocyanine, tetraazophthalocyanine, tetramethyl-7-lycyanine, and dialkylaminophthalocyanine are suitable; Can be used alone or in combination. Further, a phthalocyanine derivative in which a hydrogen atom of a benzene nucleus in a phthalocyanine molecule is substituted with at least one electron-withdrawing group selected from the group consisting of a nitro group, a cyano group, a halogen radical, a sulfone group, and a carboxyl group;
A phthalocyanine-based photoconductive material composition obtained by mixing phthalocyanine and at least one selected unsubstituted phthalocyanine compound with an inorganic acid that forms a salt with the phthalocyanine and precipitating it with water or a basic substance. You can also use objects. In this case, the electron-withdrawing fl) A, substituted phthalonanine derivative can be any one having a number of substituents in the molecule from 1 to 16, or the electron-withdrawing group-substituted phthalocyanine derivative and other J1-substituted The composition ratio with the phthalocyanine compound is preferably such that the number of substituents of the former is +1,001 to 2, preferably 0,002 to 1 per molecule of phthalocyanine unit in the composition. VIJ 7 Talocyanine-based highly luminous material composition V! Examples of inorganic acids that can form salts with phthalocyanine compounds used in the production of
1- Rosulfonic acid, hydrochloric acid, hydroiodic acid, hydrofluoric acid, hydrobromic acid and the like. Among the photoconductive materials listed above, those particularly suitable for achieving the object of the present invention include metal-free phthalocyanines, copper phthalocyanines, and derivatives thereof, such as derivatives substituted with nuclear electron-withdrawing groups. In the present invention, the concentration of the 7-talocyanine-based photoconductive material may be the same in the surface layer and the inner layer of the photosensitive layer, but preferably, the concentration is lower in the surface layer, similar to the hydrazone compound. 7 The average concentration of the talocyanine-based photoconductive material is the binder +
The concentration of the surface layer is 5 parts by weight or more, more preferably 5 to 30 parts by weight. As the amount of the 7-thalocyanine-based photoconductive material increases, the sensitivity improves, but the dark decay increases significantly and it becomes difficult to retain charge, making it less practical. As the amount of hydrazone compound or phthalocyanine-based photoconductive 12-] material decreases, the dark decay decreases, but the sensitivity decreases. This may be carried out by an appropriate method such as a method of coating Coating 1F in multiple layers.The photosensitive layer may have any number of layers, but the layer thickness is 2-30μ+n, preferably 8-25μ.

Set to 0. Of course, it may have a continuous concentration gradient. The coating method may be an air doctor coater, a blade coater, a Rontoco-9-11) hearth coater, a spray coater, or the like. The electrically insulating binder resin in J9 of the present invention may be electrically insulating thermoplastic + 34 resin or thermosetting 13 resin (such as photo-sharpening resin or photoconductive resin). All binders can be used. Examples of suitable binders include, but are not limited to, saturated polyester resins, polyamide O (fats), acrylic 114 resins, ethylene-vinyl acetate copolymers, Thermoplastic binders such as polymers, ionically crosslinked olefin copolymers (ionomers), styrene-butane enblock copolymers, polycarbonates, vinyl chloride-vinyl acetate copolymers, cellulose esters, and polyimides; epoxy (84 resin, urethane) resin, silicone t
ill fat, phenolic resin, melamine resin, xylene resin, alkyd resin, thermosetting acrylic O (thermosetting binder such as fat; photocurable (side (fat; box 1) -N-vinylcarbazo'- Photoconductivity of polyvinylpyrene, polyvinylanthracene, etc. is 0 (fat).These electrically insulating resins have a photoconductivity of 1×1()1 when measured alone.
It is desirable to have a volume resistance of 4Ω·0111 or more. As the conductive support, a sheet or drum-shaped foil or plate of copper, aluminum, silver, iron, nickel, etc. is used, or these metals are vacuum-deposited or electrolessly plated on a plastic film, etc. things are used. Effects of the Invention The photoreceptor of the present invention has a small induction effect seen in 7-thalocyanine photoreceptors, a small decrease in printing durability seen in photoreceptors using hydrazone, exhibits excellent sensitivity, and has excellent repeatability. is good. Next, the present invention will be explained by examples. In the examples, hydrazone compounds are indicated by the above-mentioned compound numbers. Cross bar example - 1 - 50 parts by weight of copper phthalocyanine and 0.5 parts by weight of nitrocopper 7 talonanine! 18% concentrated sulfuric acid Flo
1) Pour into parts by weight, precipitate the introduction products of copper 7 thalocyanine and nonitro copper phthalocyanine, and then filter and wash with water.
It was dried at 120° C. under reduced pressure. 10 parts by weight of the obtained composition was mixed with thermosetting acrylic O (acrylic A 4.0
5: 22.5 parts by weight (manufactured by Hihon Ink Co., Ltd.), melamine resin (Super Beckamine J 82 f'): 7.5 parts by weight (V), 1]-diethylamino Benzaldehydonophenylhydrazone (1) 3
o parts by weight and methyl isobutyl ketone:cellosolve acetate) (1:1)? A photoconductive paint was prepared by putting it in a ball mill bot together with the f1 mass part and kneading it for 48 hours.
This paint was applied 42 times to an 8μ image on one aluminum body -+-. Next, 10 parts by weight of the obtained composition was mixed with thermosetting a15-acrylic O (22.5 parts by weight of fat, 7.5 parts by weight of melamine resin, 9 parts by weight of p-noethylamine 7-benzaldehyde diphenylhydrazone, and methyl isobutyl ketone). : Cellosolve acetate (1:1) was placed in a ball mill pot with 70 overlapping parts and kneaded for 48 hours to prepare a photoconductive paint, and this paint was coated on the photosensitive layer at a thickness of about 8μI11 and photosensitive. Example ζ 15 parts by weight of the composition obtained in Example 1 was mixed with polycarbonate (Panlite 1300: Teijin Kasei Ltd. 94) 40
Parts by weight, 45 parts by weight of polyester U1 resin (Vylon 200: manufactured by Toyobo Co., Ltd.) and N-ethylcarbazole-
53 parts by weight of 3-fuldehydodiphenylhydrazone (6) and tetrahydro7ran:toluene (
9:1) Add tJJll and put it in ball mill bond 4
After kneading for 8 hours, a photoconductive coating material was prepared, and this coating material was coated on aluminum substrate-1 in an amount of approximately 10Iil111 times. Next, 15 parts by weight of the obtained composition, 40 parts by weight of the polycarbonate, 45 parts by weight of polyester resin, 34 parts by weight of N-ethylcarbazole-(-aldehydonophenylhydrazone, and 7 parts by weight of tetrahydrocarbonate) were added.
Add toluene (9:l) mixed solvent, put in a ball mill pot, and knead for 48 hours to prepare photoconductive paint 14. Apply this paint to the second part of the photosensitive layer described in 41j to a thickness of about 5 μm. A photoreceptor was produced. 10 parts by weight of the composition obtained in Example 1 was added to the lower layer 1 coated in Example 2 with 45 parts by weight of polycarbonate, 45 parts by weight of polyester resin and N-ethylcarbazole-3-aldehyde. 36 parts by weight of donophenylhydrazone (6) and tetrahydro7ran: toluene (9:)
) A photoconductive paint was prepared by adding it to a mixed solvent and kneading it in a ball mill bottle for 48 hours.This paint was applied to the photosensitive layer 1-1 to a thickness of about 5 μm to prepare a photoreceptor. Example 4 - On top of the 1ζ layer coated in Example 1, the photoconductive paint prepared in Example 3 was coated to a thickness of about 8 μm to prepare a photoreceptor. Example 5 40 parts by weight of metal-free phthalocyanine and 1.5 parts by weight of tetra-di-10 metal-free 7-thalocyanine in 98% concentrated sulfuric acid] (
It was dissolved in 1011 parts with thorough stirring. Pour the dissolved liquid into 5 (10) parts of water to precipitate the phthalocyanine composition, filter, wash with water and sterilize.
Dry at 20°C. Add 12 parts of this composition to hydroxyethyl methacrylate copolymer, Acrydic A.
811 ] : Large ]] Hon Ink Co., Ltd.) 13.4 stacked parts, isocyanate compound (Desmonyl N75:E
1 Polyurethane Co., Ltd.) 8.8 parts by weight, epoxy resin (Epitsu) 1 (101: Shell Chemical Co., Ltd.) 5.6 parts by weight, hydrazone compound (3) 16.7 parts by weight, and methyl isobutyl ketone :Cellosolve acetate
) (1:1) in a ball mill for 48 hours) to prepare a photoconductive paint, which was coated on an aluminum substrate to a thickness of about 8 m. The light guide obtained in Example 3 was placed on this photosensitive layer. 1
A photoreceptor was prepared by applying a photoreceptor at a rate of approximately 8 μW. 1 (Example 1) 10 parts of the composition obtained in Example 1, 22.5 parts by weight of thermosetting acrylic resin (Acrizo Ink A 405, manufactured by Irimehon Ink Co., Ltd.), and melamine (Sosou ( Super Beckamine J820, solid content 10% (manufactured by Dainippon Ink Co., Ltd.) 7.5 parts by weight,
1) 3 parts by weight and 7 parts by weight of methyl isobutyl ketone: cellosolve acetate) (1:1) were placed in a ball mill bond for 48 hours, ■? 9. Prepare a photoconductive paint and ladle this paint onto an aluminum substrate.
A photoreceptor was prepared by coating the film in micrometers. ((-Example 1) 10 parts by weight of the composition obtained in Example 1 was added to a thermosetting acrylic resin (Acrizo Ink A 4 (1,"r: Fire 1
22.5 parts by weight of 1Pon Ink Co., Ltd., melamine resin (
Super Benkamin J820: Manufactured by Dainippon Ink Co., Ltd.)
7.5 parts by weight, parts by weight of hydrazone compound (+) and 70 parts by weight of methyl isobutyl ketone: cellosolve acetate 19--) (1:1) were placed in a ball mill bottle to form a photoconductive paint. was prepared by pHI,
A photoreceptor was prepared by applying this paint to a thickness of about 15 μm on an aluminum substrate I-. 1 to Comparative Example-3 - 15 parts by weight of the composition obtained in Example 1, 40 parts by weight of polycarbonate (Panrai) K13 (manufactured by IH Teijin Kasei Ltd.), polyester (byron 20C)
): Toyobo Co., Ltd.) 45 parts by weight, 53 parts by weight of N-ethylcarbazole-3-aldehydone phenylhydrazone and tetrahydro7ran:toluene (9:1) as a solvent were added and placed in a ball mill bot for 48 hours. The mixture was kneaded to prepare a photoconductive paint, and this paint was coated on an aluminum substrate to form a chain of about 15 μm to prepare a photoreceptor. Comparative Example-4 10 parts by weight of the composition obtained in Example 1, 45 parts by weight of polycarbonate (Panrai 1300; manufactured by Yojin Kasei Co., Ltd.), polyester resin (Vylon 200: manufactured by Toyobo Co., Ltd.)
45 parts by weight of hydrazone compound (6), 20-36 parts of heavy acid and tetrahydro7rane: toluene (9
:1) A photoconductive paint was prepared by putting the mixed solvent in a ball mill bottle and kneading it for 48 hours, and this paint was coated on an aluminum substrate to a thickness of about 15 μI to prepare a photoreceptor. The obtained photoreceptor was incorporated into a commercially available electrophotographic copying machine (manufactured by Minolta Camera Co., Ltd.: EF' 30 (IRE)), and its electrostatic properties were measured. The results are shown in Table 1. In the table, vo is the initial surface potential (V) after applying DC voltage +7.5 KV, D D f<, is the decay rate (%) of the potential after being left in the dark for 1 second after charging, 1., 1/2 is the exposure amount (lux・se) until the initial surface potential becomes 1/2
e). In addition, normal continuous copying can be performed at 1110 (
The electrostatic properties when one sheet was taken were also measured. As is clear from Table 1, the photoreceptor of the present invention has good electrostatic properties, the properties are stable even during continuous copying, and there is almost no deterioration in image quality such as filming, compared to the comparative example. It is superior compared to Song Kai Example-9- ε-type copper phthalocyanine (Toyo Ink (Match) M) i. Parts by weight, 211 parts by weight of hydrazone compound example (12), 22.5 parts by weight of thermosetting acrylic In+resin (llR62 (1: manufactured by Mitsubishi Rayon), melamine resin (Kneepan 2)
0HS: Mitsui Toatsu Co., Ltd.! ! ! 7.5 parts by weight and methyl isobutyl ketone: cellosolve acetate) (]:
]) 5050 weight was placed in a ball mill pot 2 and kneaded for 48 hours, and the lead conductive paint was #11i! L: This paint was applied to an aluminum substrate to a thickness of approximately 8 μm. Next, 1 part by weight of ε-type copper phthalocyanine, 9 parts of hydrazone compound example (+2), thermosetting acrylic resin (l
lR620: 22.5 parts by weight (manufactured by Mitsubishi Rayon Co., Ltd.),
Melamine resin (knee pan 2ous knee:, Seitoatsu Co., Ltd.)
7.5 parts by weight of methyl isobutyl ketone: cellosolve acetate) (1:I) 5 (1 part by weight) were placed in a bowl and kneaded for 48 hours to prepare a photoconductive +ll paint. Approximately 8μ (1
) to prepare a photoreceptor. J tilting example-5 ε-type copper 7 talocyanine 10 parts by weight, hydrazone compound (
12) 21 parts by weight, thermosetting acrylic lf1. l Fat (H
I762 (1: Mitsubishi Rayon Co., Ltd.) 22.5 parts by weight, melamine resin 4 resin (Kneepan 2 ('lll5: Mitsui Toatsu Co., Ltd.) 7.5 parts by weight, and methyl isobutyl ketone: cellosolve acetate (1) :+) Part by weight of So was put in a ball mill bond and kneaded for 48 hours to prepare a leading conductive paint.
A photoreceptor was prepared by applying the photoreceptor so that it became μbl. Comparative Example 9 - 10 parts by weight of ε-type copper phthalocyanine, hydrazone compound (
+2) 9 parts by weight, thermosetting acrylic (fat (111 and 620: manufactured by Mitsubishi Rayon Co., Ltd.) 22.5 parts by weight, melamine (1 (fat (knee pan 2011S: manufactured by Mitsui Toatsu Co., Ltd.) 7.5 parts by weight) Parts by weight and methyl isobutyl ketone: Cellosolve acetate L (1:1) 5 (1 part by weight) were placed in a 24-mill bottle, kneaded for 18 hours, and then mixed into a round conductive layer 1*.
Prepare the paint and apply this coating to the aluminum paint.1. JA,
Coat each photoreceptor so that it has a signature of 15 μm.
1.Made. The electrostatic property +1 of the obtained photoreceptor was measured in the same manner as in Example 1. The results are shown in Table-2. -27- As is clear from Table 2, the photoreceptor of the present invention has excellent electrostatic properties and repeatability, and is an electrophotographic photoreceptor that exhibits superior properties compared to general copiers and laser printers. It is. Patent applicant: Minolta Camera Co., Ltd. ft Agent: Patent attorney: Ao 111 Ao Haga 2 people 28-

Claims (1)

[Scope of Claims] 1. In an electrophotographic photoreceptor containing a hydrazone compound represented by the following general formula [I] and a 7-lycyanine-based photoconductive material powder in the photosensitive layer, the content of the hydrazone compound in the photosensitive layer is An electrophotographic photoreceptor characterized in that the amount decreases toward the surface:\3 [wherein R1 is hydrogen, an alkyl group, or an aryl group, R
2, R3 is an alkyl group, an aralkyl group, an aryl group which may have a substituent, a fused polycyclic group which may have a substituent, n is a number of 1 or 2, and A has a substituent. represents an optional aromatic hydrocarbon group or an aromatic heterocyclic group. R2, R
, may be combined to form a ring. 1