JPH012055A - Photoconductive coating and electrophotographic photoreceptor using the same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 and its Problems" Electrophotographic photoreceptors having a photosensitive layer containing as a main component an inorganic photoconductive compound such as selenium, zinc oxide, or cadmium sulfide are widely known. However, these are not necessarily satisfactory in terms of properties such as thermal stability and durability, and they also pose problems in production and handling due to their toxicity.

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. The most well-known such organic photoconductive compound is poly-N-vinylcarbazole, which
．． Electrophotographic photoreceptors having a photosensitive layer containing a charge transfer complex formed from a Lewis acid such as 7-dolinitro and 9-fluorenone as a main component have already been put into practical use.

Furthermore, electrophotographic photoreceptors are known that have a functionally separated photosensitive layer of a laminated, eve, or dispersion type in which the carrier generation function and the carrier transport function of the photoconductor are assigned to separate substances, respectively. For example, an electrophotographic photoreceptor having a photosensitive layer consisting of a carrier generation layer made of an amorphous selenium thin film and a carrier transport layer containing poly-N-vinylcarbazole as a main component has already been put into practical use.

Furthermore, in electrophotographic photoreceptors having the above-described functionally separated photosensitive layer, attempts have been made to use organic photoconductive compounds as both the carrier-generating substance and the carrier-transporting substance.

In this case, carrier generating substances include azo dyes, phthalocyanine dyes, anthraquinone dyes, perylene dyes,
Cyanine dyes, chiapyrylium dyes, squareium dyes, etc. are known. Further, as carrier transport substances, amine derivatives, oxazole derivatives, oxadiazole derivatives, triphenylmethane derivatives, etc. are known.

These carrier-generating substances and carrier-transporting substances are
When it does not have the ability to form a film by itself, it is used in combination with various binders to form a film. Then, an electrophotographic photoreceptor is formed by laminating a layer having a carrier generation layer 'M and a layer having a carrier transport substance on a conductive support, or an electrophotographic photoreceptor in which the carrier generation substance and the carrier transport substance are dispersed. An electrophotographic photoreceptor is known in which a layer containing the above-mentioned components is formed.

However, electrophotographic photoreceptors using organic photoconductive compounds as carrier generating substances still have lower photoconductive sensitivity and durability than those using inorganic photoconductive compounds. Currently, there are very few products that can be put to practical use because they are inferior in terms of both points.

"Object of the Invention" 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.

"Structure of the Invention" The photoconductive film according to the present invention is characterized by containing at least one type of bisazo pigment represented by the following general formula (1).

R31 pel.

(In the formula, Cp represents, R represents 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, and X represents a benzene ring. Represents an atomic group necessary to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring by condensation with R. 8 may be the same or different,
In addition, 81-day represents 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). The body is characterized in that a photosensitive layer having a photoconductive coating containing at least one type of suazo pigment represented by the general formula (1) is disposed on a conductive support.

Until now, there has been no attempt to use the dosuazo pigment represented by the general formula (1) as a photoconductive compound for electrophotography. It was discovered that an electrophotographic photoreceptor with excellent sensitivity can be obtained by using chlorine as a generating substance,
This has led to the completion of the present invention.

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

Table 1 shows examples of combinations of 81 to 1 in formula (2) above.

In the above formula (3), the combination example of Cp, R1, and R2 is
Shown in the table.

(Hereinafter, blank spaces) 2 Table 2 (Continued) The compound represented by the general formula (1) can be synthesized, for example, according to the reaction formula shown in FIG. In addition, in FIG. 7, the symbols in the formula have the same meanings as those in the general formula (1). Details of this synthesis method can be found in J. Schimi.
dt, A, Ni: 4mpf, Ber,, 36.37
45 (1903), J. Schmidt, et a.
l,, Ber,, 35.3117°3+29. (
+902), L, H, ^mundsen J, Che
M, Educ, I6°567 (+939).

The electrophotographic photoreceptor of the present invention uses the organic photoconductive compound represented by the general formula (1) as a carrier generating substance, and can have, for example, the following structure.

As shown in FIG. 1 or 2, a laminate of a carrier generation layer 2 containing a carrier generation substance as a main component and a carrier transport layer 3 containing a carrier transport substance as a main component on a conductive support 1 is formed. A photosensitive layer 4 is provided. FIG. 1 shows an example in which a carrier transport layer 3 is provided on the carrier generation layer 2, and FIG. 2 shows an example in which a carrier generation #28 is provided on the carrier transport layer 3.

As shown in FIG. M3 or FIG. 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 FIG.
A photosensitive layer 4 formed by dispersing is directly on the conductive support 1,
Alternatively, it is provided via the intermediate layer 5.

The conductive support 1 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 (1 is used)

The carrier generation layer 2 is formed by turning the carrier generation substance represented by the general formula (1) into fine particles in a dispersion medium using a ball mill, a homomixer, a sand mill, a colloid mill, etc.
If necessary, a dispersion obtained by mixing and dispersing with a binder is applied, or a solution obtained by dissolving a carrier-generating substance in a binder in a solvent is applied by dipping method, spray method,
It can be formed by coating using a method such as a spinner method.

In this case, examples of the binder include phenol resin, polyester resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyvinyldololidone, polyethylene oxide, polyvinyl chloride resin, starch, polyvinyl alcohol, and acrylic resin. Copolymer resin, methacrylic copolymer resin, silicone resin,
Polyacrylonitrile copolymer resins, polyacrylamide, poly and nylbutyral, etc. can be used.

Note that the carrier generation layer 2 can also be formed by forming a compound represented by the general formula (1) into a thin film by a method such as vacuum deposition.

The carrier transport layer 3 can be formed by dispersing or dissolving a carrier transport substance in a binder similar to the above and coating the same. In the present invention, the carrier transport substance is not particularly limited, but may include, for example, amine derivatives, Oxazole derivatives, oxadiazole derivatives, triphenylmecun derivatives, etc. can be used.

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, ethylene-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.

Roughly speaking, the photosensitive layer 4 is made by dispersing a fine particulate carrier generating substance 7 in a layer 6 mainly composed of a carrier transporting substance, and the photosensitive layer 4 is made by dispersing or dissolving the carrier transporting substance in the above-mentioned binder. It can be formed by applying a liquid in which a carrier-generating substance is dispersed.

"Embodiments of the Invention" Examples 1 to 14: In a solution prepared by dissolving 2 parts by weight of butyral resin in 100 mgB of isopropyl alcohol, 5 parts by weight of the 10 types of throat azo pigments listed in the table below were ground using a ball mill. Add and disperse, 3f! A similar coating solution was prepared. Each coating solution was applied onto a 50 gm plate using a doctor blade so that the film thickness after drying would be 0.3 um, and dried to form a charge generation layer.

Next, 5 parts by weight of a hydrazone compound represented by the following structural formula and 5 parts by weight of polyvinylcarbazole were dissolved in 70 parts by weight of monochlorobenzene, and this was applied onto the charge generation layer so that the film thickness after drying was 20 mm. It was coated using a doctor blade so that the charge transport layer was formed and dried to form a charge transport layer.

10f obtained in this way! Electrostatic charge test equipment M (manufactured by Kawaguchi Electric ■, [P^-8
100 type), statically charged the corona at -6 KV, then observed the Qg decay for 5 seconds, and set the illuminance to 15 KV.
The photoelectric properties were evaluated by observing the optical attenuation with 1 ux exposure for 5 seconds. Table 11 shows the results of the initial charging potential (Vo), sensitivity (El/2), and residual potential (VR) thus measured.

(Hereinafter, blank space) Table 11 However, the sensitivity is shown as ○=good, Δ=fair, and ×-poor.

"Effects of the Invention" As explained above, according to the present invention, a photoconductive film having high sensitivity photoconductivity can be obtained by using the novel suazo pigment represented by the general formula (1). can. Moreover, by using the novel bisazo pigment represented by the general formula (1), an electrophotographic photoreceptor with good characteristics can be obtained using the resulting highly sensitive photoconductive film. Therefore, the present invention can be widely applied to electrophotographic copiers, laser beam printers, LED printers, CRT printers, or other electrophotographic applications in general.

[Brief explanation of drawings]

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. 1 is a diagram showing a reaction formula for synthesizing a bisazo pigment used in Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Procedural amendment (flag) 1. Indication of the case 1988 Patent Application No. 158443 2, Title of the invention

Claims (2)

[Claims] (1) A photoconductive film characterized by containing at least one bisazo pigment represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (In the formula, Cp is, ▲There are mathematical formulas, chemical formulas, tables, etc.) etc. ▼ where R represents 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. represents an atomic group necessary to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring. R_1 to R_4 are hydrogen atoms, lower alkyl groups, aryl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, acyl groups, halogen atoms, or monovalent organic residues. ) (2) An electrophotographic photoreceptor comprising, on a conductive support, a photosensitive layer having a photoconductive coating containing at least one type of bisazo pigment represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (In the formula, Cp is, ▲There are mathematical formulas, chemical formulas, tables, etc.) etc. ▼ where R represents 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. represents an atomic group necessary to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring. R_1 to R_4 are hydrogen atoms, lower alkyl groups, aryl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, acyl groups, halogen atoms, or monovalent organic residues. )