JPH01142730A - Photoconductive film and electrophotographic sensitive body using same - Google Patents

Abstract

PURPOSE:To obtain a photoconductive film high in sensitivity and low in residual potential and an electrophotographic sensitive body good in durability by incorporating at least one of styryl compounds specified in structure as an electric charge transfer material, and at least one of trisazo pigments specified in structure as a charge generating material. CONSTITUTION:A charge transfer layer 3 formed on a charge generating layer 2 contains at least one of the styryl compounds represented by formulae I and II in which each of Ar1-Ar4 is optionally substituted aryl, and n is 0 or 1. A charge generating layer formed between a conductive substrate 1 and the charge transfer layer 3 contains at least one of the trisazo pigments represented by formula III in which each of R1 and R2 is H, lower alkyl, or the like; Z is imino, methylene, S, O, or the like; A is a group of formula IV; X is an atomic group necessary to condense with the benzene ring to form an optionally substituted hydrocarbon ring or the like; Y is a group of formula V; and R is H, lower alkyl, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoconductive coating containing a specific organic photoconductive compound and an electrophotographic photoreceptor using the same.

[Prior art and its problems] As electrophotographic photoreceptors, those having a photosensitive layer containing as a main component an inorganic leading conductive compound such as selenium, zinc oxide, or cadmium sulfide have been widely known. However, these are not necessarily satisfactory in terms of properties such as thermal stability and durability, and furthermore, they are toxic and pose problems in production and handling.

On the other hand, electrophotographic photoreceptors having a photosensitive layer containing an organic photoconductive compound as a main component are relatively easy to manufacture, inexpensive, and easy to handle. It has attracted attention in recent years because it has many advantages, including superior thermal stability. Poly-N-onylcarbazole is the most well-known such organic photoconductive compound, and 2. C
Electrophotographic photoreceptors having a photosensitive layer containing a charge transfer complex formed from a Lewis acid such as L-trinitro-9-fluorenone as a main component have already been put into practical use.

In addition, the charge generation function and charge transport function of the photoconductor are
Electrophotographic photoreceptors are known that have functionally separated photosensitive layers of a laminated type or a dispersed type in which each material is divided into separate materials. For example, a charge generation layer consisting of an amorphous selenium thin film and a poly-N-vinyl Electrophotographic photoreceptors having a photosensitive layer including a charge transport layer containing carbazole as a main component have already been put into practical use.

Further, in electrophotographic photoreceptors having the above-mentioned functionally separated photosensitive layer, attempts have been made to use organic photoconductive compounds as both the charge-generating substance and the charge-transporting substance. In this case, known charge-generating substances include azo dyes, phthalocyanine dyes, anthraquinone dyes, perylene dyes, cyanine dyes, thiapyrylium dyes, and squareium dyes. Further, as charge transport substances, amine derivatives, oxazole derivatives, oxanoazole derivatives, triphenylmethane derivatives, hydrazone derivatives, etc. are known.

When these N-generating substances and charge transporting substances do not have the ability to form a film by themselves, they are used in combination with various binders to form a film. Then, an electrophotographic photoreceptor is formed by laminating a layer having a charge generating substance and a layer having a charge transporting substance on a conductive support, or it contains a charge generating substance and a charge transporting substance in a dispersed state. 2. Description of the Related Art Electrophotographic photoreceptors formed of layers are known.

However, electrophotographic photoreceptors using A-type conductive compounds as charge-generating substances still have low photoconductive sensitivity, poor durability, and poor photoconductivity compared to those using inorganic photoconductive compounds. Currently, there are very few products that can be put to practical use.

The present invention was made in order to solve the above problems, and provides a photoconductive film with high sensitivity and low residual potential, and an electrophotographic photoreceptor using the same, as well as charging, exposure, development, and transfer. When used as an electrophotographic photoreceptor, it is necessary to repeat the process repeatedly.When used as an electrophotographic photoreceptor, it is possible to obtain a highly durable electrophotographic photoreceptor that exhibits stable characteristics over a long period of time with little fatigue deterioration due to repeated use. is intended to provide.

[Means for Solving the Problems] The photoconductive film of the first invention contains at least one type of styryl compound represented by the following general formula [I] or [I1] as a charge transport substance, and It is characterized by containing at least one type of trisazo pigment represented by the following general formula [III] as a biological material.

(In the formula, Ar, Ar7, Ar+, and Ar all represent an aryl group that may have a substituent, and n does not represent 0 or l.

Further, R7 and R1 represent a hydrogen atom, a lower alkyl group, an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom, or a monovalent organic residue. Z is an imino group with or without substituents,
Represents a methylene group, a sulfur atom, an oxygen atom or a selenium atom with or without a substituent.

represents. X represents an atomic group necessary for condensing with a benzene ring to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring.

represents. R is a hydrogen atom, a lower alkyl group, an aryl group,
It represents an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom, or a monovalent organic residue. Each R may be the same or different. ) Further, the electrophotographic photoreceptor of the second invention has the above general formula [I] or [I] on the conductive support as a charge transport material.
A photosensitive layer is provided which has a leading conductive coating containing at least one type of styryl compound represented by [I] and at least one type of trisazo pigment represented by the following general formula [[I1]] as a charge generating substance. It is characterized by:

As a result of intensive research to achieve the above-mentioned object, the present inventors have discovered that the present inventor contains at least one type of trisazo pigment represented by the general formula [III] as a charge-generating substance, and the general formula [III] as a charge-transporting substance. Formula [I] or [II
] has discovered that the object can be achieved by a photoconductive coating containing at least one type of styryl compound and an electrophotographic photoreceptor using the same, and has completed the present invention. Ru.

That is, by using a combination of the trisazo pigment represented by the direct general formula [III] and the styryl compound represented by the general formula [I] or [II] described in 117f, high sensitivity and low residual potential are achieved, and fatigue caused by repeated use is reduced. It is possible to create a photoconductive film with good durability and little deterioration, and an electrophotographic photoreceptor using the same.

Specific examples of the styryl compound represented by the general formula [I] include the following.

Further, specific examples of the styryl compound represented by the general formula [I] include the following.

---1-------- [port]-10 ---------C port 1-11 ---1-------(II)-12 In addition, the general formula [[] Specific examples of trisazo pigments represented by the above formula include the following. Examples of Ro1, R' t, R' 3, Ro4, and Ro in the formula are shown in Table 1 attached below.

In addition, “N” in Table 1 and Tables 2 and 3 shown below
The Greek numerals [IV] to [■] written in the columns ``o'' and ``■'' indicate the numbers of the chemical formulas listed above and below.The combination of Greek numerals and Arabic numerals corresponds to the corresponding chemical formula. The number indicates the compound represented by incorporating the groups in the column indicated by Arabic numerals.

Examples of Ro1, R't and A in the above formula are shown in Table 2 attached below.

Examples of R°3, Ro2, Ro1, Ro4 and Ro in the above formula include those shown in Table 1.

Examples of Ro1, R't and A in the above formula include those shown in Table 2.

Examples of R' t, R' t, R', and R°4 in the above formula are shown in Table 3 attached below.

Examples of Rol, IR' t and A in the above formula include those shown in Table 2.

Examples of R'+, R't, R'3 and R''4 in the above formula include those shown in Table 3.

Examples of R'1, R't and A in the above formula include those shown in Table 2.

Examples of R'8, R'7, R'3 and R'4 in the above formula include those shown in Table 3.

Examples of Rol, R't and A in the above formula include those shown in Table 2.

Note that the trisazo pigment and styryl compound used in the present invention are not limited to the above-mentioned specific examples.

The styryl compound represented by the direct formula [I] can be synthesized as shown in FIG. 7, as is known in the art. In addition, the styryl compound represented by the general formula [■] is
It can be synthesized as shown in the figure. Furthermore, the general formula [I]
As shown in FIG. 9, the trisazo pigment represented by is first reduced with iron, tin, etc. to form a triamino compound, and then converted into trisazo with sodium nitrite or the like.

Coupling may be carried out as it is, but it can also be synthesized by once isolating with sodium borofluoride or the like and then coupling under alkali in a solvent such as N,N-dimethylpolamide.

In Figures 7, 8, and 9, the symbols in the formulas are:
It has the same meaning as the symbol in direct general formulas [I], [II], and [III].

The electrophotographic photoreceptor of the second invention uses the trisazo pigment represented by the general formula [III] as a charge-generating substance and the styryl compound represented by the general formula [I] or [II] as a charge-transporting substance. For example, the following configuration can be used.

As shown in FIG. 1 or FIG. 2, a laminate of a charge generation layer 2 containing a charge generation substance as a main component and a charge transport layer 3 containing a charge transport substance as a main component on a conductive support l. A photosensitive layer 4 is provided. FIG. 1 shows an example in which the charge transport layer 3 is provided on the charge generation layer 2, and FIG. 2 shows an example in which the charge generation layer 2 is provided on the charge transport layer 3.

As shown in FIG. 3 or 4, a photosensitive layer 4 similar to the above is provided on a conductive support i with an intermediate layer 5 interposed therebetween.

As shown in FIG. 5 or 6, a photosensitive layer 4 consisting of a layer 6 containing a charge transport material as a main component and a charge generating material 7 dispersed therein is deposited directly on a conductive support 1 or It is provided through the intermediate layer 5.

The conductive support l may be a metal plate, a conductive polymer, a conductive compound such as indium oxide, or paper or plastic made conductive by coating, vapor depositing, or laminating a thin film of a metal such as aluminum, palladium, or gold. is used.

The charge generation layer 2 is made by forming a charge generation substance represented by the general formula [I[[] into fine particles in a dispersion medium using a ball mill, a homomixer, a sand mill, a colloid mill, etc., and adding a binder if necessary. By applying a dispersion obtained by mixing and dispersing, or by applying a solution obtained by dissolving a charge generating substance in a binder in a solvent using a method such as a dipping method, a spray method, or a spinner method. can be formed.

In this case, examples of the binder include phenol resin, polyester resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyvinylpyrrolidone, polyethylene oxide, polyvinyl chloride resin, starch, polyvinyl alcohol, acrylic resin, etc. Polymer resin, methacrylic copolymer resin, silicone resin,
Polyacrylonitrile copolymer resin, polyacrylamide, polyvinyl butyral, etc. can be used, but the material is not limited thereto. Further, these binders may be used alone or in combination of two or more.

Note that the charge generation layer II can also be formed by forming a trisazo pigment represented by the general formula [I11] into a thin film by a method such as vacuum deposition.

The charge transport layer 3 can be formed by dispersing or dissolving a charge transport substance represented by the general formula [I] or III] in a binder and applying the mixture.

In this case, examples of the binder include phenol resin, polyester resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyvinylpyrrolidone, polyethylene oxide, polyvinyl chloride resin, starch, polyvinyl alcohol, and acrylic resin. Examples include, but are not limited to, copolymer resins, metagril-based copolymer resins, silicone resins, polyacrylonitrile-based copolymer resins, polyacrylamide, and polyvinyl butyral. Further, these binders may be used alone or in combination of two or more.

The intermediate layer 5 disposed between the conductive support 1 and the photosensitive layer 4 has a barrier function and an adhesive function, and is made of, for example, casein, polyvinyl alcohol, nitrocellulose, edylene-acrylic acid. It can be formed from copolymers, polyamides (nylon 6, nylon 66, nylon 610, copolymerized nylons, alkoxymethylated nylons, etc.), polyurethane, gelatin, aluminum oxide, and the like.

Further, in the layer 6 mainly composed of a charge transport substance, fine particles of ? The photosensitive layer 4 containing the lXlX cargo substance 7 can be formed by dispersing or dissolving a charge transporting substance in a binder such as the one described above, and further applying a liquid in which a charge generating substance is dispersed. can.

Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited to these Examples.

[Example] (Example 1) 1 part by weight of the NOl[lV]-1 trisazo pigment shown in Table 1 was added to silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., EN-
1001N), 50 parts by weight of tetrahydrofuran, and a planetary ball mill (manufactured by Fritsch Co., Ltd., P-6).
) and subjected to dispersion treatment for 6 hours to obtain a charge generation layer coating solution.

This liquid was applied onto an Aρ plate (manufactured by Toyo Aluminum Co., Ltd.) that had been degreased by UV cleaning using an electrically conductive applicator (manufactured by Riken Seimitsu Co., Ltd.). At this time, a doctor blade with a gap of 100 μm was used. Next, the coating film was dried at 40° C. for 30 minutes and at 80° C. for 1 hour to form a charge generation layer having a thickness of 0.2 to 0.4 μm.

Next, 1 part by weight of styryl compound No. [U]-3,
Polycarbonate resin (manufactured by Mitsubishi Kasei Corporation, N0VAR)
EX 7030^) was dissolved in 6 parts by weight of a mixed solution of dichloromethane and chlorobenzene to obtain a coating solution for a charge transport layer. This liquid was applied onto the charge generation layer using a doctor blade with a gap of 100 μm. Thereafter, the coating film was dried at 40°C for 30 minutes and at 80°C for 6 hours to form a charge transport layer with a thickness of 18 μm.

The photoreceptor thus produced was evaluated using an electrostatic charging tester (EPA-8100, manufactured by Kawaguchi Denki Seisakusho). At that time, a current of -28μ was passed through the charger in a static manner to cause discharge.

First, we investigated the spectral sensitivity. To measure the spectral sensitivity, the light source was converted into li-color using an optical interference filter (manufactured by Toshiba (Madhi), KL).
Sensitivity E = the light energy required to reduce the band Ti potential from approximately -700V to half by irradiating the photoreceptor with energy of 2.7μW7cm" at each wavelength.
This was done by measuring ytCμJ/cm2).

The results are shown in FIG.

Next, ■ initial charging potential V , (V ), ■ white light 5Q
Sensitivity E+7t ((
! ux-s) and (2) residual potential VR (V), which is the surface potential 10 seconds after the start of light irradiation. In addition, the charging potential was measured before and after 30 minutes of irradiation with white light of 125 (H!ux) to determine the retention rate, and the light resistance to deterioration was evaluated. The results are shown in Table 4 below.

Next, we investigated the repeatability characteristics. The repetition characteristic is the 11th
The evaluation was made by observing the 4-process shown in the figure, measuring the charged potential at each repetition, and calculating the ratio (%) to the initial value. The results are shown in FIG.

(Comparative Example) In addition, as a comparative example, a photoreceptor was prepared in the same manner as in Example 1, except that instead of the trisazo face H of NOl[IV]-1, [10 Gu ampoule-(CD[3)] was used. The characteristics of this case were evaluated in the same manner as in Example 1.

The results are shown in Table 4, Figures 10 and 12 for the lower leg. In FIG. 1O and FIG. 12, solid lines indicate Example 1.
The broken line shows the measurement result of the comparative example.

Table 4 From these results, by combining the styryl compounds represented by formulas (1) and (n) above with the trisazo pigment represented by formula (Iff) above, it is possible to improve chargeability, photosensitivity, and high characteristics. It has been found that an electrophotographic photoreceptor can be obtained which has a low residual potential and has excellent repeatability and light deterioration resistance.

(Examples 2-2) Trisazo pigment N used in Example I as a charge generating substance
o, [iV] - 1 was replaced with the trisazo pigment listed in Table 5, and the styryl compound No. used in Example 1 was used as the charge transport material, [[l] = 5 instead of 3. Using the styryl compounds listed in the table, an electrophotographic photoreceptor was prepared in the same manner as in Example 1, and the initial charging potential, sensitivity, and residual potential of this electrophotographic photoreceptor were measured to evaluate each characteristic. Ta. The results are shown in Table 5 attached below.

The electrophotographic photoreceptors of Examples 2 to 21 all showed good characteristics, but among them, Examples 2, 6. +2°16.20 etc. have particularly good chargeability and sensitivity, have a small residual potential, and are found to be suitable as electrophotographic photoreceptors.

In addition, Examples 2 to 21 (B) exhibited excellent characteristics similar to those of Example I in terms of repetition characteristics and light deterioration resistance.

[Effects of the Invention] As explained above, according to the present invention, the direct coupling formula [I
] or [I11] By using a combination of at least one type of styryl compound represented by [I11] and at least one type of trisazo pigment represented by the above general formula [[I1], high sensitivity and low residual potential can be obtained, and it can be used repeatedly. It is possible to obtain a photoconductive film with good durability and less fatigue deterioration, and an electrophotographic photoreceptor using the same.

Therefore, the present invention can be widely applied to electrophotographic application fields in general, such as electrophotographic copying machines, laser beam printers, LED printers, and CRT printers.

Margin below

[Brief explanation of the drawing]

1, 2, 3, 4, 5 and 6 are sectional views showing different specific examples of the layer structure of the electrophotographic photoreceptor according to the present invention, and FIGS. The figure shows the reaction formula for synthesizing styryl compounds represented by the general formulas [(] and [II] used in the present invention, respectively.
The figure shows a reaction formula for synthesizing the trisazo pigment represented by the general formula [III] used in the present invention. Figure 10 is a graph showing the results of the spectral sensitivity investigated in Example I.
The figure shows the T = I' value curve of the repetition characteristics investigated in Example 1.
FIG. 12 is a graph showing the results of repeated characteristics of J and 9 solids in Example 1.

Claims (2)

[Claims] (1) As a charge transport substance, the following general formula [I] or [
A photoconductive coating comprising at least one styryl compound represented by formula [II] and at least one trisazo pigment represented by the following general formula [III] as a charge generating substance. ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−［
I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−[I
I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−[I
II] (In the formula, Ar_1, Ar_2, Ar_3, Ar_4 all represent an aryl group that may have a substituent, and n represents 0 or 1. In addition, R_1, R_2, R_3 are a hydrogen atom, a lower alkyl group , represents an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom or a monovalent organic residue.Z is an imino group with or without a substituent, a methylene group with or without a substituent, Represents a sulfur atom, an oxygen atom, or a selenium atom.A is ▲There are mathematical formulas, chemical formulas, tables, etc.▼▲There are mathematical formulas, chemical formulas, tables, etc.▼▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲Mathematical formulas, chemical formulas, tables, etc. etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ . Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼.R represents a hydrogen atom, a lower alkyl group, an aryl group,
Represents an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom, or a monovalent organic residue. Each R may be the same or different. ) (2) Containing at least one type of styryl compound represented by the following general formula [I] or [II] as a charge-transporting substance on the conductive support, and containing at least one styryl compound represented by the following general formula [III] as a charge-generating substance. An electrophotographic photoreceptor comprising a photosensitive layer having a photoconductive coating containing at least one type of trisazo pigment. ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−［
I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−[I
I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−[I
II] (In the formula, Ar_1, Ar_2, Ar_3, Ar_4 all represent an aryl group that may have a substituent, and n represents 0 or 1. In addition, R_1, R_2, R_3 are a hydrogen atom, a lower alkyl group , represents an aryl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom or a monovalent organic residue.Z is an imino group with or without a substituent, a methylene group with or without a substituent, Represents a sulfur atom, an oxygen atom, or a selenium atom.A is ▲There are mathematical formulas, chemical formulas, tables, etc.▼▲There are mathematical formulas, chemical formulas, tables, etc.▼▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲Mathematical formulas, chemical formulas, tables, etc. etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ . Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼.R represents a hydrogen atom, a lower alkyl group, an aryl group,
Represents an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a halogen atom, or a monovalent organic residue. R may be the same or different. )