JPH01180560A - Photoconductive film and electrophotographic sensitive body formed by using said film - Google Patents

Abstract

PURPOSE:To obtain a photoconductive film having high sensitivity and an electrophotographic sensitive body formed by using said film by using a specific hexaazo compd. CONSTITUTION:At least one kind of the hexaazo compd. expressed by the formula I is used as a photoconductive compd., more particularly, charge generating material for electrophotography. In the formula I, A denotes the formula II, etc.; R1, R2 denote a hydrogen atom, lower alkyl group, etc., Z denotes an atomic group necessary for forming a substd. or unsubstd. carbon arom. ring or hetero system arom. ring by condensing to a pyrazine ring; Ar1-Ar3 respectively denote a substd. or unsubstd. hydrocarbon or hetero system arom. cyclic group or bivalent residual org. group. R denotes a hydrogen atom, lower alkyl group, aryl group, etc. The photoconductive film having the high sensitivity is thereby obtd. and the electrophotographic sensitive body having good characteristics is obtd. by using this film.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a photoconductive coating containing a novel organic photoconductive compound and an electrophotographic photoreceptor using the same.

[Prior art J3 and its problems] As electrophotographic photoreceptors, those having a photosensitive layer containing as a main component an inorganic photosensitive compound such as selenium, curved lead oxide, or cadmium cum sulfide are widely known. . However, these are not necessarily satisfactory in terms of properties such as thermal stability +1.1 and durability, and furthermore, they are toxic, which poses problems for manufacturers 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 such as superior thermal stability. Poly-N rubinylcarbazole is the most well-known such photoconductive compound, and 2,4
Electrophotographic photoreceptors having a photosensitive layer containing a charge transfer complex formed from a Lewis acid such as 7-dolinyl-0-9-fluorene 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 a laminated type or dispersed type functional pre-type photosensitive layer in which each material is assigned to a separate material. For example, a charge generation layer consisting of an amorphous selenium thin film and a poly-N- Electrophotographic photoreceptors having a photosensitive layer including a charge transport layer containing vinyl carbazole as a main component have already been put into practical use.

Furthermore, in the electrophotographic photoreceptor having the above-mentioned functionally separated photosensitive layer, attempts have been made to use organic photoconductive compounds as both the charge generation material J3 and the charge transport material. In this case, known charge generating substances include G, U, azo dyes, phthalocyanine dyes, anthra-↓non dyes, perylene dyes, cyanine dyes, thiapyrylium dyes, and squareium dyes. Further, as charge transport substances, hydrazone derivatives, amine derivatives, oxazole derivatives, oxadiazole derivatives, triphenylmethane derivatives, etc. are known.

These charge-generating substances and charge-transporting substances are used in combination with various binders to form a coating, unless they themselves have a film-forming ability. Then, an electrophotographic photoreceptor is formed by laminating a layer containing a charge-generating substance and a layer containing a charge-transporting substance on a conductive support, or a state in which the charge-generating substance and the charge-transporting substance are dispersed. An electrophotographic photoreceptor is known in which a layer containing .

However, electrophotographic photoreceptors using organic photoconductive compounds as charge-generating substances still have lower photoconductive sensitivity and durability than those using inorganic photoconductive compounds. However, due to their inferiority, there are currently very few products that can be put to practical use.

An object of the present invention is to provide a highly sensitive photoconductive coating and an electrophotographic photoreceptor using the same by employing a novel organic photoconductive compound.

(Means for Solving the Problems) The photoconductive film according to the present invention is characterized by containing at least one type of hexaazo compound represented by the following general formula (I).

Be2 (wherein A represents, and R does not 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) .X represents an atomic group necessary to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring by condensation with a benzene ring.

represents. R's may be the same or different.

Furthermore, R+ and Rz 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! j, , Z represent an atomic group necessary to form a substituted or unsubstituted carbon-based aromatic ring or heteroaromatic ring by condensation with the pyrazine ring. Art, Ar2. Ar
3. Ar.

does not represent a substituted or unsubstituted hydrocarbon or heteroaromatic ring group, or a divalent organic residue, respectively. Art
"-□Ar'4 may be the same or different.) Furthermore, the electrophotographic photoreceptor according to the present invention has at least one hexaazo compound represented by the general formula (I) on the conductive support. The present invention is characterized by providing a photosensitive layer having a photoconductive coating containing a type of photoconductive film.

Until now, there has been no attempt to use the hexaazo compound represented by the general formula (T) as a photoconductive compound for electrophotography. It was discovered that an electrophotographic photoreceptor having excellent sensitivity can be produced by using the compound as a 1-substance, and the present invention has been completed.

Specific examples of the compound represented by the general formula (I) (J) include the following.

In the above formula (If), R1', R2', Arl-・A
Examples of r4 combinations are shown in Table 1 attached below.

In the above formula (III), the second example of the combination is attached later.
It's on the table.

In the formula ([V), R+', R2', Ar+~Ar
Examples of combinations of 3 are not shown in Table 3 attached later.

Examples of combinations of A in the above formula (V) are shown in Table 4 attached later.

The compound represented by the general formula (I) can be prepared, for example, according to the reaction formula shown in FIG. Coupling is done inside. The blue tri-7-mino form was further diazotized with sodium [iF'flW and hydrochloric acid, or sulfurium dinitrate and sulfuric acid, and the naphthol A
It is obtained by coupling with an S-based coupler in an alkali. In addition, in FIG. 7, the symbols in the formula have the same meaning as the symbols in the general formula <I).

The electrophotographic photoreceptor of the present invention uses the organic photoconductive compound represented by the general formula (I>) as a charge-generating substance, and can have, for example, the following structure.

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 1. A photosensitive Ff 44 is provided. FIG. 1 shows an example in which a charge transport layer 3 is provided on a charge generation layer 2, and FIG. 2 shows a charge transport FJ3.
This is an example in which a charge generation layer 2 is provided on top of the charge generation layer 2.

As shown in FIG. 3 or 4, a photosensitive layer 4 similar to that described above is provided on a conductive support 1 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 directly deposited on a conductive support 1. , or provided via the intermediate layer 5.

As the conductive support 1, 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 if necessary, coagulating and dispersing the charge generation substance with a binder. Apply the dispersion obtained by
Alternatively, it can be formed 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.

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. Usable examples include toga copolymer resin, methacrylic copolymer resin, silicone resin, polyacrylonitrile copolymer resin, polyacrylamide, and polyvinyl butyral.

Note that the charge generation layer 2 can also be formed by forming a thin film of the compound represented by the general formula (I) by a method such as vacuum deposition.

The charge transport layer 3 can be formed by dispersing or dissolving a charge transport substance in a binder similar to the above and applying the same. In the present invention, the charge transport substance is not particularly limited, but for example, hydrazone derivatives, amine derivatives, oxazole derivatives, oxadiazole derivatives, triphenylmethane derivatives, etc. can be used.

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

Furthermore, the photosensitive layer 4 is formed by dispersing a particulate charge generating substance 7 in a layer 6 mainly composed of a charge transporting substance, by dispersing or dissolving the charge transporting substance in the binder as described above,
Furthermore, it can be formed by applying a liquid in which a charge generating substance is dispersed.

(Example) Examples 1 to 12 Butyral resin type 2 hanging part was mixed with isopropyl alcohol 10
5 parts by weight of the 12 types of trisazo pigments listed below were added and dispersed in a ball mill to a solution containing 0 parts by weight to prepare 12 types of coating liquids. Then, each coating solution was applied onto a 50 ta N plate using a doctor blade so that the film thickness after drying would be 0.3 IIJR, and dried to form a charge generation layer.

Next, a hydrazone compound type 5 part shown by the structural formula below and a polygonylcarbazole 70 suspended part were dissolved, and this was placed on the charge generation layer so that the film thickness after drying was 20 Im. It was applied using a doctor blade and dried to form a charge transport layer.

The 12 types of electrophotographic photoreceptors thus obtained were tested using an electrostatic charging tester (manufactured by Kawaguchi Electric, EPA-810).
0 type), statically charged the corona at 16KV, then observed dark decay for 5 seconds, and set the illuminance to i51ux.
The photoelectric properties were evaluated by observing the optical attenuation after exposure for 5 seconds. The initial charging potential (Vo) and sensitivity (E
172), and the results of residual potential (V') are shown in Table 5 below.

Table 5 However, the sensitivity is shown as 〇-good, △=fair, ×-poor.

[Effect of the invention] As explained above, according to the present invention, by using the novel hexaazo compound represented by the general formula (I),
A photoconductive coating having highly sensitive photoconductivity can be obtained. Further, by using the novel hexaazo compound represented by the general formula (I>), an electrophotographic photoreceptor with good characteristics can be obtained using the resulting highly sensitive photoconductive film. Therefore, The present invention applies to electrophotographic copying machines, laser beam printers, LED printers, C
It can be widely applied to general electrophotographic application fields such as RT printers.

[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 FIG. 7 is the sectional view according to the present invention. FIG. 2 is a diagram showing a reaction formula for synthesizing a hexaazo compound used in FIG.

Claims (2)

[Claims] (1) A photoconductive film characterized by containing at least one type of hexaazo compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, A is, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ where R is a hydrogen atom, lower alkyl group, aryl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, Represents a halogen atom or a monovalent organic residue. X represents an atomic group necessary for condensing with a benzene ring to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring. Y has ▲mathematical formula, chemical formula, table, etc.▼ or ▲mathematical formula,
There are chemical formulas, tables, etc. ▼ Represents. R's may be the same or different. Further, R_1 and R_2 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 represents an atomic group necessary to form a substituted or unsubstituted carbon-based aromatic ring or heteroaromatic ring by condensation with the pyrazine ring. Ar_1, Ar_2, Ar
_3 and Ar_4 each represent a substituted or unsubstituted hydrocarbon-based or heteroaromatic ring group, or a divalent organic residue. Ar_1 to Ar_4 may be the same or different. ) (2) An electrophotographic photoreceptor comprising, on a conductive support, a photosensitive layer having a photoconductive coating containing at least one type of hexaazo compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, A is, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ where R is a hydrogen atom, lower alkyl group, aryl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, Represents a halogen atom or a monovalent organic residue. X represents an atomic group necessary for condensing with a benzene ring to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring. Y has ▲mathematical formula, chemical formula, table, etc.▼ or ▲mathematical formula,
There are chemical formulas, tables, etc. ▼ Represents. R's may be the same or different. Further, R_1 and R_2 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 represents an atomic group necessary to form a substituted or unsubstituted carbon-based aromatic ring or heteroaromatic ring by condensation with the pyrazine ring. Ar_1, Ar_2, Ar
_3 and Ar_4 each represent a substituted or unsubstituted hydrocarbon-based or heteroaromatic ring group, or a divalent organic residue. Ar_1 to Ar_4 may be the same or different. )