JPH03180852A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent deterioration of mechanical strength of a photosensitive body and to enhance mobility by blending a specified electric charge transfer polymer with a charge transfer material low in molecular weight. CONSTITUTION:This photosensitive body contains the polymer charge transfer material (A) composed of structural units of formula I having hydrazone groups and a molecular weight of 1,000 - 50,000 and at least one kind of charge transfer material (B) low in molecular weight, such as p-diethylaminobenzaldehyde-N,N- diphenylhydrazone. In formula I, R is H, 1 - 4C alkyl, or the like; and each of (m) and (n) is a positive number and m/n is <= 100. As the component A, the compound of formula I in which R is H, and the like can be used.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to an electrophotographic photoreceptor using a polymeric charge transfer material having a hydrazone group, and more specifically relates to an electrophotographic photoreceptor using a charge generating material and a charge transfer material. The present invention relates to an electrophotographic photoreceptor containing a polystyrene compound, which is a polymeric charge transfer material having a didracine group, as a charge transfer material, and one or more types of low molecular weight charge transfer materials.

[Prior art and its problems] Conventionally, selenium (Se) and cadmium sulfide (CdS) have been used as photoconductive materials for photoreceptors used in electrophotography.
), M-oxide t4f (ZnO), and 7-E rufus silicon (a-3i).

Although these inorganic photoreceptors have many advantages, they also have various disadvantages, such as being harmful and being expensive. For this reason, in recent years, many organic photoreceptors using JJ machine materials that do not have these drawbacks have been proposed and put into practical use.

The structure of these photoreceptors includes a material that generates charge carriers (hereinafter referred to as charge generation material) and a material that receives and moves the generated charge carriers (hereinafter referred to as charge generation material).
There are two types of photoreceptors: a multilayer structure with a functionally separated photoreceptor in which charge transfer materials (called charge transfer materials) are formed in separate layers, and a single layer structure with a single-layer photoreceptor in which charge carrier generation and charge transfer are performed using the same material. However, multilayer structures are more widely used because they offer a wider range of material selection and higher sensitivity.

In recent years, with the development of non-impact printing technology, research and development of electrophotographic printers using laser light sources have been actively conducted. In these devices, as the device size becomes smaller and the speed increases, it is desired that the photosensitive materials have higher sensitivity in charge generation materials and higher mobility in charge transfer materials.

In the case of charge transfer materials, it is known that the mobility greatly depends on the concentration of the transfer material (e.g., triphenylamine compounds) in the binder (e.g., polycarbonate) (Takahashi, Kanbayashi).

Yokoyo, Electrophotography, 25.16 (1986)). If the concentration of the mobile material is increased, the mobility will increase, but the physical properties will deteriorate, for example, cracks will occur. Furthermore, mechanical wear is increased during the passage of the paper during printing. Therefore, it is difficult to add a charge transfer material to a binder (binder resin) at a high concentration.

The present invention was made in view of the conventional circumstances as described above, and by blending a polymer charge transfer material with one or more types of low molecular charge transfer materials, it is possible to achieve high mobility without reducing mechanical strength. An object of the present invention is to provide an electrophotographic photoreceptor containing a charge transfer material that provides the following characteristics.

[Means for Solving the Problems] As a result of continuing research in view of the conventional situation, the present inventors have developed a method that combines a polymer having a charge-transfer functional group and one or more types of low-molecular charge-transfer materials. By blending,
It has been found that high mobility can be achieved without using a high concentration of low-molecular charge transfer materials.

That is, the present invention provides an electrophotographic photoreceptor comprising a charge generating material and a charge transporting material, - film type [■]: ... [I] (wherein R is a hydrogen atom, a lower carbon atom having 1 to 4 carbon atoms, represents an alkyl group, an alkoxyl group, or a dialkylamino group, m and n are each positive integers, and m/n is 100 or less.) with a molecular weight of 1000 to 5000.
A polymeric charge transfer material having 00 hydrazone groups, and 1
The present invention is an electrophotographic photoreceptor characterized in that it contains at least one kind of low-molecular charge transfer material as a charge transfer material.

The polymeric charge transfer material used in the present invention is represented by the above-mentioned membrane type [I], and concrete examples include those shown in Table 1, but similar compounds are effective. ,
It is not limited to these.

(Left below) Table 1 The polymeric charge transfer material shown in the above-membrane type [I] is -
Membrane form [1] (wherein R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group, or a dialkylamino group.

It can be produced by copolymerizing the hydrazone group-containing styrene compound represented by the following formula and the styrene monomer represented by the -membrane type [1] in an appropriate ratio.

For example, the first production method is to first produce a Grignard reagent of 4-chlorostyrene, and then add dimethylformamide (DMF) to produce 4-pormylstyrene (J, 1. Dale, l-3ta).
rr and C, W, 5trobel, J.
Org, Chem, 26°1965, 2225>
. Next, a desired 1,1-diarylhydrazine compound is added to 4-formylstyrene and condensed in the presence of an acidic catalyst to produce a hydrazone group-containing styrene compound represented by the membrane type [n]. This monomer and the general formula [I11
] The polymeric charge transfer material used in the present invention can be obtained by mixing the styrene monomers represented by the following in an appropriate ratio and copolymerizing the mixture using a polymerization initiator if necessary.

In addition, the second method uses 4
- After protecting the aldehyde group of formylstyrene as a 7-cetal, the compound and styrene are polymerized in the presence of a suitable polymerization initiator, and then hydrolyzed in an acidic solution to remove the acetal group. -Producing a formylstyrene copolymer. Then, the polymeric charge transfer material of the present invention can also be obtained by reacting this copolymer with a hydrazine compound.

In the present invention, the polymeric charge transfer material represented by -membrane type [I] is chloroform or methylene chloride.

Easily soluble in solvents such as tetrahydrofuran, methanol,
Insoluble in ethanol.

Examples of low-molecular charge transfer materials include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-
N-phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole N,N-Schiffnylhydrazino 3-methylidene-10-ethylphenothiazine, N. tonphenylhydrazino-3-medylidene-1
0-Ethylphenoxazine, p-dibenryaminobenzaldehyde N,N-diphenylhydrazone, p-diedylaminobenzaldehyde N-α naphthalene N-phenylhydrazone, p-pyrrolidinobenzaldehyde
N,N-diphenylhydrazone, 2-methyl-4-dibenzylaminobenzaldehyde-1-ethyl-1°-benzothiazolylhydrazone, 2-methyl-4-dibenzylaminobenzaldehyde-1°-propyl-1°- Benzothiazolylhydrazone, 2-methyl-4-dibenzylaminobenzaldehyde-1°,1′-diphenylhydrazino, 9-ethylcarbazole-3-carphoky1naldehyde 1°-medyl-1°-phenylhydrazone,
1-benzyl-1.2,3.4-tetrahydroquinoline-6-carpoxyaldehyde 1',1'-diphenylhydrazone, 1,3.3-trimethylindolenine-
ω-aldehyde-N,N-Schiff ■ diruhydrazone, p-
Hydrazones such as diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole, 1-phenyl-3-(p- diethylaminostyryl) -5-(p-diethylaminophenyl>pyrazoline, 1-(quinolyl (2))-3-(1)-diethylaminostyryl) -5-(o-diethylaminophenyl>pyrazoline, 1-(pyridyl (2) )-3-(
p-diethylaminostyryl) -5-(1)-diethylaminophenyl>pyrazoline, 1-(6-medoxybilidyl(2))-3-(1)-diethylaminostyryl>-5-(p-diethylaminophenyl>pyrazoline , 1-(pyridyl(3))-3-(p-diethylaminostyryl)-5-(1)-diethylaminophenyl>pyrazoline, 1-(pyridyl(2))-3-(p-diethylaminostyryl) 4-methyl -5-(p-diethylaminophenyl)pyrazoline, 1-(pyridyl(2))-
3-(α-methyl-p-diethylaminostyryl) −
5-(p-diethylaminophenyl)pyrazoline, 1-
Phenyl-3-(p-diethylaminostyryl)-4-
Pyrazolines such as methyl-5-(p-diethylaminophenyl>pyrazoline, 1-phenyl-3-(α-benzyl-p-diethylaminostyryl)-5-(1)-diethylaminophenyl)-6-pyrazoline, spiropyrazoline, 2 -(1)-diethylaminostyryl)-6
-dinithylaminobenzoxazole, 2-(p-
oxazole compounds such as diethylaminophenyl)-4-(1)-diethylaminophenyl)-5-(2-chlorophenyl)oxazole, thiazole compounds such as 2-(D-diethylaminostyryl)-6-dinitylaminobenzothiazole, Triarylmethane compounds such as his(4-diethylamine-2-methylphenyl)-phenylmethane, 1.1-bis(4-N, N-diethylamino-2-methylphenyl)hebutane, 1,
4. Polyarylalkanes such as 1,2,2-tetrakis(4-N,N-dimethylamino-2-methylphenyl)ethane, stilbene compounds such as 1,1-diphenyl-p-diphenylaminoethylene; 4. Triarylamino compounds such as 4°-3-methylphenylphenylamine biphenyl are used.

The electrophotographic photoreceptor of the present invention preferably has an undercoat layer, a charge generation layer, and a charge transfer layer laminated in this order on a conductive substrate. It may be a layered structure or a structure in which a charge generating agent and a charge transfer agent are dispersed and coated with a suitable resin on the underprint. Further, these undercoat layers can be omitted if necessary.

Electric? i? j When the transfer layer and the charge generation layer are functionally separated, the charge transfer layer is made into a hard film by casting a solution in which the polymeric charge transfer material and the low molecular charge transfer first grain as described above are dissolved. It is possible,
It is extremely useful as a charge transfer layer for electrophotographic photoreceptors.

The polymeric charge transfer material contained in the charge transfer material of the charge transfer layer is 100% by weight or less, preferably about 50% by weight.
is suitable.

The charge transfer material contained in the charge-like IJJG is
100% by weight or less, preferably 100% by weight,
A binder resin may be added if necessary.

Further, these resins may be used alone or in combination of two or more.

Examples of the electrically insulating binder (binder resin) to be contained in the charge transfer layer include phenol resin, urea resin, melamine resin, epoxy resin, silicone resin, vinyl chloride-vinyl acetate copolymer, butyral resin, and xylene resin. , urethane resin, acrylic resin, polycarbonate resin, polyacrylate resin, saturated polyester resin, phenoxy resin and the like.

The solvent for dissolving the charge transfer material and the binder resin varies depending on the type of resin, etc., and is preferably selected from those that do not affect the charge generation layer and undercoat layer, which will be described later, during coating. Specifically, aromatic hydrocarbons such as bembin, xylene, ligroin, monochlorobenzene, and dichlorobenpine, ketones such as ahitone, methyl ethyl ketone, and cyclohexylinone, alcohols such as methanol, ethanol, and isopropanol, and ethyl acetate.

Esters such as methyl cellosolve, carbon tetrachloride.

Chloroform, dichloromethane, dichloroethane.

Aliphatic halogenated hydrocarbons such as 1-lychloroedylene, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and sulfoxides such as dimethyl sulfoxide. type is used.

The thickness of the charge transfer layer of the electrophotographic photoreceptor is 10
~25 k is preferable.

Roughly, various commonly used additives such as ultraviolet absorbers and antioxidants are appropriately added to this charge transfer layer.
II is effective in preventing deterioration.

Examples of the conductive substrate used in the present invention include a plastic film provided with a thin layer of aluminum 1 cum, nickel, chromium, etc., and paper or plastic film coated with or impregnated with a conductive substance.

The charge generation layer may be made of a known photoconductive material, such as Se.
, CdS, ZnO, or other inorganic materials, or Cu, Al,
Phthalocyanines containing metal atoms such as Irl, Ti, Pb, and V, inorganic phthalocyanines, azo pigments,
Bisazo pigments, cyanine pigments, etc.
These materials can be used alone or in combination.

In addition, the electrically insulating binder (binder resin) contained in the charge generation layer is a phenol resin.

Urea resin, melamine resin, epoxy resin, silicone resin, vinyl chloride-vinyl acetate copolymer, butilal resin,
Examples include xylene resin, urethane resin, acrylic resin, polycarbonate resin, polyacrylate resin, saturated polyester resin, and phenoxy resin. The proportion of the charge generating material contained in the charge generating layer is suitably 0.05 to 90% by weight, preferably 30 to 65% by weight.

Further, the solvent that dissolves these resins varies depending on the type of resin, and it is desirable to select one from among those that do not dissolve the undercoat layer, which will be roughly described later.

Specific organic solvents include alcohols such as methanol, ethanol, and isopropyl alcohol, acetone,
Ketones such as medylethyl ketone and cyclohexane,
N,N-dimethylformamide.

Amides such as N,N-dimethylacetamide, Te1~
Ethers such as hydrofuran, dioxane, and ethylene glycol methyl ether, esters such as methyl acetate and ethyl acetate, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and 1-lichloroethylene. Alternatively, aromatic compounds such as benzene, toluene, xylene, monodichlorobenbin, dichlorobenzene, etc. can be used.

At this time, the thickness of the charge generation layer is approximately 0.1 to 0.5 in order to maintain chargeability and ensure stability. Furthermore, a plasticizer or the like can be used together with the binder if necessary. Coating can be performed using a coating method such as a dipping coating method, a spray coating method, a wire bar coating method, a blade coating method, or a roller coating method.

In addition to these layers, an undercoat layer can be provided on the conductive substrate for the purpose of preventing a decrease in chargeability and improving adhesion. Binders used for the undercoat layer include nylon 6, nylon 66, nylon 11. nylon 610
．． Alcohol-soluble polyamides such as copolymerized nylon and alkoxymethylated nylon, cavin, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, gelatin, polyurethane, and polyhinyl butyral are used. The method for forming the lower layer can be the same as that for the charge generation layer described above. At that time, the film thickness of the undercoat layer is O11-20, preferably 0.
A tone of 5 to 10 is best. Further, these subbing layers can be omitted if necessary.

The electrophotographic photoreceptor of the present invention can be used not only with laser beam printers but also with semiconductor lasers with a wavelength of 750 to 850 nm.
The present invention can also be applied to various other optical storage devices using light sources.

Hereinafter, the present invention will be specifically explained, and the present invention is not limited to the following examples unless it exceeds the gist thereof.

[Example] Examples of the present invention will be described in detail below.

II! In Example 1, a polystyrene compound represented by formula (3) was produced by the method shown in the following series of reaction formulas.

00Ctl=CH2゜(In the formula, m/n is 1.〉 14.79 ml of magnesium metal, 20 d of ethyl ether, and a small amount of ethyl bromide were added to a 11 flask, and heated. Furthermore, 81.8 g of 4-chlorostyrene/tetrahydrofuran (THF>
400 d of solution was added over a period of 3 hours. During the reaction, heat is generated and the temperature reaches a high temperature, so cool it in a water bath and cool the reaction solution to 50%.
The temperature was maintained below 0°C.

After the dropwise addition was completed, the reaction was continued for another 2 hours at room temperature.

Dimethylformamide (DMF>43.8 g) was added dropwise over a period of 2 hours, and the mixture was allowed to stand overnight at room temperature.

500 ml of ethyl ether was added, and the reaction solution was added to a dilute aqueous hydrochloric acid solution. After extraction, the ethereal region was washed with pure water and then dried over magnesium sulfate. After distilling the ether,
4-formylstyrene was produced by distillation (boiling point 70°C
/ 0.8mmH! J). The yield was 42g (63%).

Production of compound (2) Compound (1) produced by the above method 66 g, 1゜1-
diphenylhydrazine 92.59, benzene 300d,
Then, a small amount of para-toluenesulfonic acid was placed in a 500-flask equipped with a Dean-Starck receiver and heated.
Time passed quickly. After the reaction was completed, benzene was distilled off and recrystallized from methanol to obtain compound (2) as a pale yellow solid with a melting point of 79°C.

Preparation of compound (3) In a 50 m flask, 15 g of compound (2) and 5 g of styrene were added.
cJ, 15 d of benzene was charged, and azobisisobutyronitrile (AIBN>0.5 g was added. 60°C
After polymerization was carried out for 24 hours, the polymerization solution was poured into a large amount of methanol. The resulting solid was dried at 50'C under reduced pressure. Yield: 17.5 g, average molecular weight: AAA
, ooo, compound (3) with a number average molecular weight of 84,000
I got it.

Production Example 2 In this production example, polystyrene compound (4) represented by formula (3) was placed in a 100-d flask by the method shown by the following reaction formula. Poly(p-formylstyrene costyrene) (compound (4)) 59.1,1-diphenylhydrazine 159, tetrahydrofuran (T port F>
50 mA, p-toluenesulfone 9 was charged, and the reaction was carried out at room temperature for 4 hours. After the reaction was completed, tetrahydrofuran was distilled off under reduced pressure, 50 g of benzene was added, and the solution was poured into 500 g of methanol. The obtained solid product was filtered and dried to produce compound (3). The yield was 12.3 g.

Example 1 Af! An undercoat made of nylon was formed on the substrate, and a phthalocyanine-containing butylal film (0.1 mm thick) was coated on the undercoat layer as a charge generation layer. On this charge generation layer, Polymer charge transfer material (polystyrene compound obtained in Production Example 2, m/n-1)/Low molecular charge transfer material (p-diethylaminobenzaldehyde-N, N
-diphenylhydrazone>/methylene chloride (1:1:2
The solution (weight ratio) was applied at 15% and baked at 80'C for 130 minutes to immediately form a charge transfer layer with a thickness of 15%.

After bringing the surface potential to -1100V with a -5kV corona discharge using an electrostatic copying tester, irradiation with light at an illuminance of 5 lux, time (seconds) until the surface potential becomes 1/2 and obtained the half-decreased exposure ME1/2 (lux seconds).The result is V3-980 V, F
1/2 = 0.90 rutz') It showed high sensitivity of 1/2 = 0.90 rutz'). The mechanical properties were also very good.

FIG. 1 is a schematic cross-sectional view of the photoreceptor manufactured in this example.
In the figure, 1 is an AI2 substrate, 2 is a charge generation layer, 3 is a charge transfer layer, and 4 is an undercoat layer.

[Effect of the Invention 1] As explained above, according to the present invention, by blending a polymeric charge transfer material with one or more types of low molecular charge transfer materials, a charge that provides high mobility without decreasing mechanical strength can be produced. An electrophotographic photoreceptor containing the moving material 8 is obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of one embodiment of the present invention.

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor containing a charge-generating material and a charge-transfer material, the general formula [I]; ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, R is a hydrogen atom, a carbon Represents a lower alkyl group, alkoxyl group or dialkylamino group having 1 to 4 atoms, m and n are each positive integers and m/n is 100 or less.) with a molecular weight of 1000
An electrophotographic photoreceptor comprising, as a charge transfer material, a polymeric charge transfer material having ~500,000 hydrazone groups and one or more types of low molecular charge transfer materials.