JPS59151158A - Single layer type electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To eliminate an induction effect and to improve the sensitivity of the titled sensitive body using photoconductive phthalocyanine powder in the visible light region by incorporating a specified disazo pigment and a specified pyrazoline compound into the photosensitive layer. CONSTITUTION:A disazo pigment represented by formula I (where X is -OCH3 or Cl) such as Dian blue and a pyrazoline compound represented by formula II[where (n) is 0 or 1, and each of A, A1 and A2 is aryl] such as 1-phenyl-3-(p- dimethylaminostyryl)-5-(p-dimethylaminophenyl)-pyrazoline are used as sensitizers. A photoconductive coating material is prepd. by kneading photoconductive phthalocyanine powder with said disazo pigment, said pyrazoline compound and a binder resin, and the coating material is applied to an electrically conductive support to form a photosensitive layer of about 2-20mum thickness. Thus, a single layer type electrophotographic sensitive body is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-layer photoreceptor for electrophotography, in which a photosensitive layer in which a phthalocyanine-based photoconducting powder is dispersed in a binder resin is provided on a conductive support.

Photoreceptors for photosensitive photography are generally of the laminated type, in which a conductive conductor is provided with an electric generation layer made of a fully vaporized selenium compound, and an electric charge transport layer made of an insulating resin; There is a single-layer type in which a photosensitive layer in which photoconductive powder is dispersed in a stone agent resin is disposed on a conductive support.In the former laminated type, there is no trapping of generated telegraphs, and there is no induction caused by exposure. On the other hand, it is difficult to manufacture because it requires #, right.Secondly, Se etc.
It has no flexibility and is highly toxic, so care must be taken when handling it. Although it has the advantage of having an induction effect, there is a high degree of ease in manufacturing that compensates for its shortcomings, and in recent years, DF of car layer photoreceptors,
One shot tends to advance.

Furthermore, as single-layer photoreceptors, there are those that use cadmium chloride, zinc oxide, etc. as photoconductive powders, and those that use phthalocyanine materials, which are the subject of the present invention, as photoconductive powders. In the former case, if the resin ratio is large, practical sensitivity cannot be obtained, so the resin ratio must be made small, and mechanical strength such as OJ flexibility, smoothness, hardness, and abrasion resistance is low. Furthermore, there is a drawback that it is degraded by ozone and the like generated due to corona charging, and research and development of the latter method is progressing because it has fewer of these drawbacks.

Furthermore, in a 7-lysocyanine yarn paint photoreceptor using a phthalocyanine-based material, it is desired to reduce the induction effect red that is characteristic of a single layer type, and conventionally, trinitroanthracene, 2.4.7, trinitrofluorenone, etc. polycyclic or heterocyclic nitro compounds, phthalic anhydride, acid anhydrides such as phthalic anhydride, chloranil,
Various electron acceptor substances such as chloranil were contained in the photosensitive layer as sensitizers.

However, both the sensitivity and the induction effect were inferior to those of the above-mentioned laminated type photoreceptor.

In view of the above points, the present invention provides a single-layer type photoreceptor that has excellent mechanical strength and is less affected by ozone, etc., as well as manufacturing aspects, and further has excellent sensitivity similar to that of a laminated type photoreceptor. No induction effect
The purpose is to improve sensitivity in the optical head area.

In order to achieve the above object, the present invention provides the electrophotographic single-layer photoreceptor described above, in which a disazo pigment represented by the following general formula is added to the photosensitive layer, and a disazo pigment represented by the following general formula + 11
n: o also 1. l:1”-N-N A, A,,
A2・Taniya・j−・shi group.

It is characterized by adding a pyrazoline compound represented by as a sensitizer.

In other words, through experiments using various sensitizers, it was found that by including the above-mentioned pyrazoline compound in the photosensitive layer, it was possible to improve the angle of 16 degrees to 1 degree, as shown in the actual results below, and it was The induction effect, which was thought to be unavoidable in the human body, can be eliminated, and the addition of disazo pigments improves the sensitivity in the town holiday light area, making it possible to copy red stamps, etc., which are often used in office work. So, overall, while taking full advantage of the inherent advantages of phthalocyanine-based Kuingu sensitizers, which are advantages in terms of manufacturing and mechanical strength, and the ability to suppress deterioration due to ozone, etc., we have also improved sensitivity and It has been possible to provide a photoreceptor for electrophotography which is excellent in all of the injection effects, is highly practical, inexpensive, and is extremely useful in practice, allowing copies with high gradation to be obtained.

As the photoconductive phthalocyanine powder in the present invention, all known photoconductive phthalocyanines or their derivatives can be used, and examples of suitable combinations include )1j (metallic phthalocyanine, aluminum phthalocyanine, antimony). Phthalocyanine, /chlorphthalocyanine, perilikumphthalocyanine, /ri”nadicium 7 lycyanine, cadmium hexadecachlorophthalocyanine, cobalt phthalocyanine, cobalt chlorophthalocyanine, cadmium phthalocyanine, vanadyl 7
Talocyanine, copper-4-aminophthalocyanine, copper-4
- chlorophthalocyanine, copper-4-nitrophthalocyanine, charophthalocyanine, dysprosum phthalocyanine, dharmicum 7-yugacyanine, phormicum phthalocyanine, iron phthalocyanine, iron phorihalophthalocyanine, lead 7 thalocyanine, lead polychlorophthalocyanine, These are 7-lycyanine compounds such as cobalt hexaphenyl phthalocyanine, dialkylamino 7-thalocyanine, tetra-azophthalocyanine, tetramethyl phthalocyanine, tetraphenylphthalocyanine, platinum phthalocyanine, zinc Z-lysocyanine, and sulfonated phthalocyanine.

Phthalocyanines or derivatives thereof which are easily available and which are particularly suitable for the purposes of the present invention are metal-free phthalocyanines, copper-7 lysocyanines and their nuclear substituted derivatives, such as nuclear halogen substituted derivatives.

As the electrically insulating binder resin in the present invention, all known electrically insulating binders such as thermoplastic resins, thermosetting resins, photocurable resins, and organic photoconductive resins can be used. can be used.

Specific examples of suitable binder resins include, but are not limited to, saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate copolymers, ionically crosslinked olefin copolymers (ionomers), and styrene. - Thermoplastic binders such as butadiene block copolymer, polycarbonate, vinyl chloride-hinyl acetate, monomer, cellulose ester, polyimide, etc.: epoxy resin, flex resin, silicone resin, phenol resin, melamine resin, Thermosetting resin agents such as xylene resin, thermosetting acrylic resin, unsaturated polyester resin, acrylic resin, photocuring binder such as photocuring acrylic resin, PoIJ-N
- An organic photoconductive resin agent such as vinylulpasol, polyvinylpyrene, polyvinylanthracene, etc., preferably an acrylic resin.

These electrically insulating resins have l x l when measured individually.
It is desirable to have a volume resistivity of O''Ω or more.

Specific examples of the disazo face H in the present invention include Diane Blue, Bromdiane Blue, and Chlorogyan Blue.

Specific examples of pyrazoline compounds include 1-phenyl-8
[p-dimethylaminostyryl] = 5-[p-dimethylaminophenylcupirazoline, 1-phenyl-8[p
-diethylaminostylyl]-5-Cp-diethylaminophenyl]-pyrazoline, 1-phenyl-a (p-
methoxystyryl)-5-1:'p-methoxyphenyl]-pyrazoline and the like.

Pyrazoline compound is a phthalocyanine thread photoconductive powder 1
It is preferable to use 3 to 50 parts by weight, particularly 5 to 40 parts by weight, per 0 parts by weight. That is, when the amount of the pyrazoline compound is greater than the above range, the darkening rate tends to be rapid and the initial surface potential of the photosensitive layer tends to decrease with repeated repetition, and when the amount is less than the above range, the sensitization is impaired. It has no effect, and on the contrary, it desensitizes and is sweet.

On the other hand, the phthalocyanine-based photoconductor and the electrically insulating resin are mixed as solid components at a ratio of 1:20 to 1:10.
Use at a weight ratio of l:l improves electrophotographic properties,
The photosensitive layer has excellent mechanical properties.

End of the story:! In addition to the above-mentioned conductive powder wood, disazo pigment, and pyrazoline compound, any additives or compounding agents known per se can be blended into the photoreceptor described above, if desired.

For example, examples of such compounding agents include thickeners, thinners, anti-sagging agents, swelling agents, antifoaming agents, and dye sensitizers, which are known per se.

Akira's photoreceptor is prepared by preparing a photosensitive emulsion by dispersing it in a bath medium, spreading it on an isoelectric pattern, and then repeating it on a table. It is made from lζ.

As the above-mentioned conductive support, a sheet or drum-shaped sheet or drum of oil or plate of steel, luminicum, silver, iron, Nilaglu, etc. is used, or gold of these materials is used.
It can be used by applying it to a glass film or the like in a thin and vague manner by means of plating, electroless plating, etc.

The photosensitive layer of the present invention preferably has a thickness of 2 to 20 microns, particularly 6 to 16 microns.

As mentioned above, the photoreceptor of the present invention is highly sensitive to a wide range of wavelengths, and is stable even after repeated exposure.
It does not suffer from the induction effect (time delay in potential decay immediately after exposure) that is characteristic of phthalocyanine-based binder photoreceptors, and has good gradation reproducibility and fine line reproducibility, making it suitable for various electrophotographic photoreceptors, especially for high-speed copying. It can be applied to various uses such as photoreceptors, laser printers/light bodies, etc.

Examples of the present invention, comparative examples, and comparative experiment results will be described below.

Example 1 10 parts by weight of metal-free phthalocyanine (Heliogen Blue 7800 manufactured by BASF) and 0.0 parts by weight of a disazo pigment having the following structural formula.
8 parts by weight and 1-phenyl-8 [p-diethylaminostyryl)'5
- (15 parts by weight of p-diethylaminophenylcupirazoline) was kneaded and dried in a ball mill for 24 hours with 40 parts by weight of a thermoplastic acrylic resin (Guillanard LR320 manufactured by Mitsubishi Rayon Co., Ltd.) and a solvent of n-butanol/celeryl pacetate-1/1. An electrophotographic photoreceptor was prepared.

Comparative Example 1 In the formulation of Example 1, disazo pigment and 1-phenyl-
A photoreceptor was produced in exactly the same manner as in Example 1, except that 8Cp-'; ethylaminostyryl)5-(p-diethylaminophenyl2pyrazoline) was removed.

Comparative Example 2 The first formulation of Example 1 except for disazo face P+, and
1-phenyl-8(p-diethylaminostyryl)-5
(A photoreceptor was prepared in exactly the same manner as in Example 1, except that 1 part by weight of 2,4,7-dolinitrofluorenone was added instead of p-diethylaminophenyl-pyrazoline.

Comparative Example 8 The disazo pigment was excluded from the formulation of Example 1, and 1
-Phenyl-3 [p-diethylaminostyrane)-5
-1: A photoreceptor was prepared in exactly the same manner as in Example 1, except that 3 parts by weight of 4-nitrophthalic anhydride was added to the p-diethylaminophenyl-pyrazoline layer.

Each of the obtained photoreceptors was installed in a commercially available electrophotographic copying machine (EP810 manufactured by Minolta Camera@) and its electrostatic properties were measured, and the results shown in Table 1 were obtained. However, V in the table. is the initial surface potential when DC voltage +7.5 KV is applied, v5 is the surface potential after being left in the dark for 5 seconds after charging,
E2GO is the exposure amount until the initial surface potential becomes 200 .

Table 1 Also, when the light attenuation characteristics of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 were measured, graphs as shown in FIGS. 1 and 2 were obtained. In FIG. 2, (B) indicates Comparative Example 1, (B) indicates Comparative Example 2, and tel indicates Comparative Example 3.

From the above results, although the dark decay characteristics are not very good, the photoreceptor according to the present invention has about 8 times the sensitivity compared to the one without using a sensitizer, and the photoreceptor does not use a conventional sensitizer. The sensitivity is about three times higher than that of the previous one, and the men are shown to have extremely superior sensitivity.

Comparative Example 4 A photoreceptor was produced in exactly the same manner as in Example 1 except that the disazo pigment was not added to the formulation of Example 1. The electrostatic properties of Comparative Example 4 were measured in the same manner as in the above case.

The results shown in Table 2 were obtained.

Table 2 Also, when the spectral sensitivities of Example 1 and Comparative Example 4 were measured, the graph shown in FIG. 8 was obtained. In contrast, Example 1 is shown by a solid line, and Comparative Example 4 is shown by a broken line.

From the above results, while the desired initial surface potential and exposure amount can be obtained, by adding disazo pigments, the spectral sensitivity can be extended to the short wavelength side, and the spectral sensitivity extends into the visible light region. It is clear that the sensitivity has been improved.

Therefore, even if the red color reproducibility is improved by cutting off the long wavelength side, there is no problem in practical sensitivity, and it is now possible to copy red color etc. satisfactorily.

Example 2 10 parts by weight of ε-type copper 7-lysyanine (Onor Blue ER manufactured by Toyo Ink ■) and disazo face No. 5 having the following structural formula
25 parts by weight of 1-phenyl-3[p-diethylaminostyryl]-5-(1)-diethylaminophenylcupirazoline were added to natural plastic acrylic resin (Mitsui Higashi l
f ■ Crack 0XL-97) 45 heavy minerals and butyl acetate/Seroturu 7 part acetate = 1/l solvent were kneaded in a VC ball mill for 24 hours, applied to a light guide '4 type paint, and then dried. In this way, an electrophotographic photoreceptor was produced.

The electrostatic properties of Example 2 were measured in the same manner as described above, and the results shown in Table 3 were obtained.

f! JJs Table Also, the same results as in Example 1 were obtained regarding the spectral sensitivity.

4 Section Juice rj Q, Explanation Fig. 1 is a graph showing the light number retention property of Example 1, Fig. 2 shows the light number retention characteristics of Comparative Example 1, Comparative Example 2L-, and Comparative Example 3, respectively. Is the graph, Figure 8, the comparative measurement results for spectral sensitivity? This is a graph showing.

Claims (1)

[Scope of Claims] A single-layer electrophotographic photoreceptor comprising a photosensitive layer in which a phthalocyanine-based photoconductive powder is dispersed in a lip binder resin on a conductive support, wherein the photosensitive layer includes a disazo compound represented by The pigment has the following general formula (%): A, AI, A2: Tani quaryl group. A single-layer type photoreceptor for electrophotography, to which a pyrazoline compound is added as a sensitizer.