JPS59184347A - Electrophotographic sensitive material - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive material contg. a phthalocyanine photoconductor dispersed in resin and having superior sensitivity by adding a specified amount of 3,5-dinitrobenzoic acid as a charge transferring substance to an electrically insulating resin medium. CONSTITUTION:This electrophotographic sensitive material cotains a phthalocyanine photoconductor-base charge generating substance dispersed in an electrically insulating resin medium contg. 3,5-dinitrobenzoic acid as a charge transferring substance by 1.8-4pts.wt. per 100pts.wt. resin medium. When the 3,5 -dinitrobenzoic acid is used in combination with the phthalocyanine photoconductor, it acts as not a sensitizer but a charge transferring substance and can receive and transfer charge carriers generated from the phthalocyanine photoconductor under irradiated light.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic material, and more particularly to an electrophotographic material with excellent sensitization properties.

Conventionally, photosensitive materials made by dispersing 7-crocyanine-based photoconductive pigments as charge-generating substances in an electrically insulating medium have been widely used in the field of electrophotography. Also as a chemical sensitizer, trinitroanthrane, 2°4, 7. - Various electron acceptor substances are known, such as polycyclic or heterocyclic nitro compounds such as trinitronefluorenone, acid anhydrides such as fucuric anhydride and trimellidic anhydride, and talolanil and promanil.

However, in recent years, organic electrophotographic photoreceptors have been used to absorb light,
It is known that a photoreceptor consisting of a so-called charge-generating substance that generates electric charge and a so-called charge-transfer substance that receives and transfers the generated charge carriers has a good optical GlW, and the characteristics of each substance are as follows. , various studies have been conducted.

The present inventors selected a phthalocyanine-based photoconductor as a charge generating substance, and a 35-
It has been found that by selecting dinitrobenzoic acid and incorporating it into an electrically insulating medium, an extremely superior sensitizing effect can be obtained compared to conventional sensitizers.

An object of the present invention is to provide an electrophotographic photosensitive material having a phthalocyanine photoconductor-resin dispersion system and having excellent sensitivity.

That is, the present invention provides an electrophotographic photosensitive material comprising a charge-generating substance mainly composed of a 7-cyanine-based photoconductor dispersed in an electrically insulating resin medium, wherein the resin medium contains 35-dinitro as an electrotransfer substance. The present invention provides an electrophotographic light-sensitive material characterized in that it contains benzoic acid in an amount of 1.8 to 44 years per 100 parts of the resin medium.

3,5-dinitrobenzoic acid used in the present invention is a type of Lewis acid, and exhibits electron-accepting properties. Generally, when combined with a charge-generating substance, a Lewis acid simply plays the role of a so-called sensitizer that promotes the generation of charge from the charge-generating substance. When phthalocyanine-based photoconductors are selected and used in combination, 35-dinitrobenzoic acid acts not only as a sensitizer but also as a charge transport substance, and is generated from the phthalocyanine-based photoconductor upon irradiation with light. The charged charge carriers can be accepted and transferred.

In the present invention, it is important to incorporate 35-dinitrobenzoic acid in an amount of 1.8 to 44 parts by weight, more preferably 55 to 44 parts by weight, per 100 parts by weight of the electrically insulating medium. When the amount of 35-dinitrobenzoic acid is less than the above range, as is clear from FIG. 1 created from the examples described later, favorable results in terms of sensitivity cannot be obtained.
If the amount exceeds the above range, 35-dinitrobenzoic acid will crystallize in the photosensitive layer, and the film forming properties of the photosensitive layer will deteriorate significantly, making it almost unusable.

In the present invention, the phthalocyanine photoconductor includes:
All phthalocyanines or derivatives thereof which are known per se and have photoconductivity can be conveniently used, suitable examples of which are aluminum phthalocyanine, aluminic polychlorphthalocyanine, acitimone fucrocyanine, barium phthalocyanine, heliricum phthalocyanine, cadmium Hexadecal rolphthalocyanine, cadmium fucrocyanine,
Sericum fucrocyanine, chrome phthalocyanine, co/chlor phthalocyanine, co/chlor phthalocyanine, copper 4-aminophthalocyanine, copper bromochlorofucrocyanine, copper-4-chlorofucrocyanine, copper-4
- Nitro-7 crocyanine, copper phthalocyanine, sulfone In, copper polychlorofucrocyanine, deuteriofucrocyanine, dysprosum fucrocyanine, erbicum fucrocyanine, europium phthalocyanine, gadolinium fucrocyanine, gallium phthalocyanine,
Kermanicum phthalocyanine, phormicum phthalocyanine, indium fucrocyanine, iron phthalocyanine, iron polynolophthalocyanine, lanthanum phthalocyanine,
Lead phthalocyanine, lead polychlorofucrocyanine, cobalt hexaphenyl phthalocyanine, copper pentaphenyl phthalocyanine, lithium phthalocyanine, ° lutetium phthalocyanine, magnesicum phthalocyanine, manganese phthalocyanine, mercury phthalocyanine, molybdenum phthalocyanine, naphthalocyanine, neodymium phthalocyanine, nitro 7-crocyanine, Nickel polyallophthalocyanine, osmicum phthalocyanine, palladium phthalocyanine, palladium chlorophthalocyanine, alkoxyphthalocyanine, alkylaminophthalocyanine, alkylmercaptophthalocyanine, alkylaminophthalocyanine, allyloxyphthalocyanine, allylmercaptophthalocyanine, copper fucrocyanine piperidine, cycloalkylaminophthalocyanine, sial 4
/ Rareaminophthalocyanine, dialkylaminophthalocyanine, dicycloalkylaminophthalocyanine,
Hexate'cahydrophthalocyanine, imidomethylphthalocyanine, 1,2-naphthalocyanine, 2,3-naphthalocyanine, octaazophthalocyanine, sulfur phthalocyanine, tetra-azophthalocyanine, tetra-4-
Acetylaminofuclocyanine, tetra-4-aminopenzoyl phthalocyanine, tetra-4-aminophthalocyanine, tetrachloromethylphthalocyanine, tetradiazophthalocyanine, tetra-4,4-dimethyloctaazophthalocyanine, tetra-4,5- Diphenylene dioxide fucrocyanine, tetra-4,5-diphenyloctaazophthalocyanine, tetra-(6-1f rubenzothiazoyl)fucrocyanine, tetra-p-methylphenylaminophthalocyanine, tetramethylphthalocyanine, tetra-naphthotria Solfthalocyanine, tetra-4-naphthylphthalocyanine, tetra-4-
Nitrophthalocyanine, tetra-berinaphthalocyanine
4,5-octaazophthalocyanine, tetra-2,3-
7-enylene oxide phthalonanine, tetra-4-phenyl octaazophthalocyanine, tetra-phenyl phthalocyanine, tetra-phenylphthalocyanine tetracarboxylic acid, tetra-phenyl fucrocyanine, tetra-baricum carboxylate, tetra-phenyl fucrocyanine, tetra -4-Trifluoromethylmercaptophthalocyanine, tetrapyridyl phthalocyanine, tetra-
4-trifluoromethylmercaptophthalocyanine, tetra-4-trifluoromethylphthalocyanine, 4,5
- Thionaphthene octaazophthalocyanine, platinum phthalocyanine, potassium phthalocyanine, rhodicum phthalocyanine, samaricum phthalocyanine, silver phthalocyanine, silicone phthalocyanine, naphthylphthalocyanine,
Sulfonated phthalocyanine, trichum phthalocyanine,
Thulium phthalocyanine, tin chlorophthalocyanine, tin phthalocyanine, titanium phthalocyanine, uranium phthalocyanine, vanadium phthalocyanine, ytterbicum phthalocyanine, auxiliary chlorphthalocyanine,
Zinc phthalocyanine and its dimers, trimers, oligomers, polymers, copolymers, etc.

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

In the present invention, as the electrically insulating resin medium, any electrically insulating thermoplastic resin or thermosetting resin binder known per se can be used. Examples of suitable binders include, but are not limited to, saturated polyester Jugetsu, polyamide Jugetsu, acrylic Mjj Jl,
Thermoplastic binders such as ethylene-vinyl acetate copolymer, ionically crosslinked olefin copolymer (ionomer), styrene butadiene block copolymer, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide; Epoxy wax 4 fat, Tsuretan 1F effect, silicone tree effect, phenol ladder I month effect, melamine tree effect,
Thermosetting binders such as xylene, thermosetting acrylic resin, saturated polyester resin, bismaleimide resin, and alkyd resin. These electrically insulating materials are
It is desirable to have a volume electrical resistance of 1014 Ω-σ or more when measured alone.

The phthalocyanine-based light guide box body uses electrically insulating resin in an amount of 5 to 100, preferably IO to 50, per 100 kg of the resin as a solid content, depending on the electrophotographic properties and various mechanical properties of the photosensitive layer. Desirable in terms of characteristics.

In addition to the three essential components, any additives or compounding agents known per se may be added to the photographic material of the present invention, if desired. For example, such compounding agents include thickeners, thinners, anti-sagging agents, leveling agents, antifoaming agents, dye sensitizers, etc., which are known per se.

The photosensitive material of the present invention can be applied to an electrophotographic photosensitive plate by dissolving or dispersing it in an organic solvent to prepare a coating composition, applying this coating composition onto a conductive substrate, and then drying it. shall be.

Specific solvents for preparing the coating composition include aromatic hydrocarbons such as benzene, toluene, and xylene; cyclic ethers such as dioxane and tetrahydrofuran; ketones such as methyl ethyl ketone, methyl imbutyl ketone, and cyclohexanone; Alcohols such as acetone alcohol, ethylene glycol, isodithyl ether;
One type or a combination of two or more types of alicyclic hydrocarbons such as cyclohexane (9) can be used.
-Dinitrobenzoic acid is easily mixed with these organic solvents, so that a homogeneous coating composition can be prepared. Reading of the coating composition is easily accomplished by dispersing the phthalocyanine photoconductor in a fatty solution and dissolving the phthalocyanine-35-dinitrobenzoic acid therein. ,
In general, it is preferable to have a solid content concentration of 1 to 50%, particularly 5 to 30%, from the viewpoint of coating workability.

The above-mentioned conductive substrates include copper, aluminum, silver,
Sheets or drums made of tin, iron, etc. foils or plates are used, or these metals are applied to plastic film paper, etc. in the form of a thin film by vacuum deposition, electroless plating, etc. is used.

゛) The photosensitive composition of the present invention can be applied onto the substrate as a layer having a thickness of generally 2 to 20 μm, particularly 3 to 10 μm in terms of solid content.

Since the photosensitive composition of the present invention exhibits excellent sensitivity as described above, it can be used in various applications such as photosensitive plates for electrophotography (and photosensitive plates for laser printers, etc.).

The invention is illustrated by the following example.

Example 1 Polyester resin (Pylon 200 manufactured by Toyobo Co., Ltd.) 1
00 i position 35-dinitrobenzoic acid
24 parts by weight cyclohexanone
160 heavy ff 3 silicone oil (KF-96 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.05 heavy box part The above composition was placed in a ball mill and dispersed for 24 hours. 100'
C and dry for 30 minutes to form a 12μ film! ? A photosensitive plate having the following was produced.

Examples 2 to 9 Photosensitive plates were prepared in the same manner as in Example 1, except that the amount of 35-dinitrobenzoic acid was changed to the formulation shown in Table 1 below, and i- was omitted by one.

The sensitivity and charging characteristics of the photosensitive plate thus prepared were measured.

The measurement was carried out using an electrostatic paper analyzer manufactured by Kawaguchi Electric KK, using the following tea juice.

7+111 h=mode 5tat 2 applied voltage E
+6. The irradiation light was 301 ux, and a half-reduced 1 lux, 5 ec) was used for the sensitivity.

The measurement results are shown in Table 2.

Based on the measurement results in Table 2 and above, the horizontal axis represents the loss of 35-dini)o benzoic acid for 100 parts of electrically insulating resin medium, and 0' h for charging on the fir shaft. The results were calculated and plotted as a graph.

These measurement results showed that 35-dinitrobenzoic acid behaves as a charge transporting substance (in contrast to phthalocyanine photoconductors) and that it has excellent sensitivity as a 118 optical material.

[Brief explanation of drawings]

FIG. 1 shows the power, strength, and chargeability of each photosensitive phase for the compounding of 35-dinitrobenzoic acid. Patent applicant: 31 Industry Co., Ltd.

Claims (1)

[Claims] An electrophotographic photosensitive material comprising a charge-generating substance mainly composed of a 7-talocyanine-based photoconductor dispersed in an electrically insulating resin medium, wherein the resin medium contains 3 as a charge-transfer substance.
An electrophotographic light-sensitive material comprising 5-dinitrobenzoic acid in an amount of 1B to 44 parts by weight per 100 parts by weight of a resin medium.