JPS63284556A - Photoconductive film and electrophotographic sensitive body using it - Google Patents

Abstract

PURPOSE:To obtain a photoconductive film high in sensitivity and an electrophotographic sensitive body using it by incorporating at least one kind of trisazo pigment having a structure represented by a specified formula. CONSTITUTION:The photoconductive film contains at least one of the novel bisazo pigments represented by formula I in which Z is an atomic group necessary to form an optionally substituted aromatic hydrocarbon ring or hetero ring by condensing with a pyrazine ring; and A is represented by formula II, thus permitting the photoconductive film to be enhanced in sensitivity and the electrophotographic sensitive body having said film to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION 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]

As electrophotographic photoreceptors, those having a photosensitive layer containing as a main component an inorganic photoconductive 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 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. Poly-N-vinylcarbazole is the most well-known such organic photoconductive compound, and 2. /1
．． Electrophotographic photoreceptors having a photosensitive layer containing a charge transfer complex formed from a Lewis acid such as nitro-9-fluorenone as a main component have already been put to practical use.

In addition, electrophotographic photoreceptors are known that utilize functionally separated photosensitive layers, such as laminated or dispersed types, in which the carrier generation function and the carrier transport function of the photoconductor are separated into separate substances. 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. .

Further, in the electrophotographic photoreceptor having the above-mentioned 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, the 11799-generating substances include azo dye,
Known examples include phthalocyanine dyes, anthraquinone dyes, perylene dyes, cyanine dyes, deapyrylium dyes, and squareium dyes. Further, as carrier transport substances, amine transducers, 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-generating substance and a layer having a carrier-transporting substance on a conductive support, or it contains a carrier-generating substance and a carrier-transporting substance in a dispersed state. 2. Description of the Related Art Electrophotographic photoreceptors formed of layers are known.

However, electrophotographic photoreceptors that use organic photoconductive compounds as carrier generating substances still have lower photoconductive sensitivity than those that use inorganic photoconductive compounds. However, due to their poor durability, there are currently very few practical ones.1 The purpose of the present invention is to develop a highly sensitive photo-S conductive material by employing a novel organic photoconductive compound. An object of the present invention is to provide a transparent film and an electrophotographic photoreceptor using the same.

[Means to speed up problem solving]

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

(In the formula, represents an atomic group necessary for condensing with a pyrazine ring to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring.) The photographic photoreceptor has the general formula (1) on the conductive support.
The present invention is characterized by providing a photosensitive layer having a photoconductive coating containing at least one type of trisazo pigment represented by:

Until now, there has been no attempt to use the trisazo pigment represented by the general formula (1) as a photoconductive compound for electrophotography.
The present inventor discovered that by using this pigment as a photoconductive compound for electrophotography, particularly as a carrier generating substance, an electrophotographic photoreceptor having excellent sensitivity can be obtained.
This has led to the completion of the present invention. .

Specific examples of the compound represented by the general formula (1) include the following.

In the formula, examples of combinations of R1-R5 are shown in Table 1.

(Margin below) Table 1 91 In the formula, examples of combinations of 81 to B3 are shown in Table 2 of the attached sheet.

The compound represented by the general formula (1) can be synthesized, for example, according to the reaction formula (I) as shown in the attached sheet. The symbols in reaction formula (I) have the same meanings as those in general formula (1). Details of this synthesis method can be found in Ber, 35
, 3117 (1902) and Ber, , 18,
1942 (1885).

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 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 are laminated on a conductive support 1. A photosensitive layer 4 is provided. FIG. 1 shows an example in which a carrier transport layer 3 is provided on a carrier generation layer 2, and FIG.

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 carrier generating substance 7 in the form of fine particles is contained in a layer 6 mainly composed of a carrier transporting substance.
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, or paper or plastic made conductive by coating, vapor depositing, or laminating a conductive compound such as a conductive polymer or indium oxide, or a metal thin film such as aluminum, palladium, or gold. is used.

The carrier generation layer 2 is made by forming 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., and mixing and dispersing the substance with a C binder as necessary. It can be formed by applying the resulting dispersion, or by applying a solution obtained by dissolving a carrier-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 done.

In this case, the binder may be, for example, fuconol resin,
Polynisder resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyvinylpyrrolidone, polydilene oxide, polyvinyl chloride resin, starch, polyvinyl alcohol, acrylic copolymer resin, methacrylic copolymer resin, silicone Resins, polyacrylonitrile copolymer resins, polyacrylamide, polyvinyl butyral, etc. can be used.

Note that the carrier generation layer 2 can also be formed by forming a thin film of the compound represented by the general formula (1) 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 applying the same. In the present invention, the main 1/rear transport substance is not particularly limited, but for example, amine derivatives, oxazyl Is forms, oxadiazole derivatives, triphenylmethane derivatives, etc. can be used.

Note that the intermediate layer 5 disposed between the conductive support 1 and the photosensitive layer 4 provides a barrier function and an adhesive function, and is made of, for example, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer. , polyamide (Vuylon 6, Vylon 66, Vylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc.

Furthermore, the photosensitive layer 4 is formed by dispersing a fine particulate carrier-generating substance 7 in a layer 6 mainly composed of a carrier-transporting substance. Furthermore, it can be formed by applying a liquid in which the main 11 rear-generating substance is dispersed.

[Embodiments of the invention]

(Examples 1 to 10) 2 parts by weight of butilal resin and 10 parts by weight of isopropyl alcohol
Three types of coating liquids were prepared by adding and dispersing the most part of the 10 types of trisazo pigment type 5 listed in the table below, which were ground using a ball mill, into a solution containing 0 parts by weight. and,
Each coating solution was applied onto a 50cm N plate so that the film thickness after drying was 0.
．． Apply using a doctor blade so that there are 3 parts,
It was 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 valve q layer so that the film thickness after drying was 20 mm. Apply with a doctor blade so that
It was dried to form a charge transport layer.

The 10 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 16 KV, then observed dark decay for 5 seconds, and set the illuminance to 15 lu.
The photoelectric properties were evaluated by observing the optical attenuation by exposure to x for 5 seconds. Initial charging potential (Vo) and sensitivity (Vo) measured in this way
El/2) and residual potential (VR) results are shown in Table 3 below.

Table 3 However, the sensitivity is shown as 〇-good, △=fair, and ×=poor.

(Effects of the Invention) As explained above, according to the present invention, by using the novel organic photoconductive compound represented by the general formula (1), a photoconductive coating having high sensitivity photoconductivity and An electrophotographic photoreceptor can be obtained 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.

[Brief explanation of drawings]

FIGS. 1, 2, 3, 4, 5, and 6 are cross-sectional views, but do not show specific examples of the layer structure of the electrophotographic photoreceptor according to the present invention.

Claims (2)

[Claims] (1) A photoconductive coating containing at least one trisazo pigment represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−(I) There are tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ . (Represents the atomic group necessary to form a system aromatic ring.) (2) An electrophotographic photoreceptor comprising, on a conductive support, a photosensitive layer having a photoconductive coating containing at least one trisazo pigment represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼−−−−−−−(1
) (A in the formula 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. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Numerical formulas, chemical formulas, tables, etc. are available▼, and Z represents an atomic group necessary to form a substituted or unsubstituted hydrocarbon or heteroaromatic ring by condensation with the pyrazine ring.)