JPS6050538A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve sensitivity, gradation, repetition characteristics, etc. by forming a photosensitive layer contg. a specified phthalocyanine compsn. and an electrostatic charge transfer substance. CONSTITUTION:Phthalochanine and phthalocyanine deriv. prepared by substituting at least one electron attractive group selected from nitro, CN, halogen, SO3H, and COOH on the benzene ring for H are mixed with an inorg. acid capable of forming a phthalocyanine salt, and precipitated by using water or a basic substance. A charge transfer substance, such as hydrazone compd., is incorporated in a layer contg. said obtained phthalocyanine compsn. as a charge generating substance to form a photosensitive layer. A photosensitive body having such a photosensitive layer has no sanitary problem, and since it is of a positive chargeable type, it produces a small amt. of ozone when it is used, and it has high sensitivity and small induction. Since its light attenuation curve forms a J curve, it is superior in gradation, and small in deterioration due to repeated uses, and a superior image can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a hydrazone compound, a hydrazone compound,
Pyrazoline compounds.

By containing a charge transporting substance such as an oxadiazole compound or a triphenylamine compound, it can be used as a positively charged photoreceptor to improve photosensitivity, ozone resistance, abrasion resistance, image quality stability with repeated use, and image gradation. An object of the present invention is to provide an electrophotographic photoreceptor having excellent properties and hygiene.

Generally, in electrophotography, a photoreceptor with a thin film of conductor elements such as selenium or cadmium sulfide formed on a metal drum is charged in a dark place, and a light image is irradiated (It light) as in xerography. .

After forming an electrostatic latent image, a visible image is created using toner (
Development) A method of transferring and fixing this onto paper, etc.

Alternatively, there is a method such as the electrofax method in which a photoconductive layer (photosensitive layer) is provided on paper, and a permanent visible image is obtained on the photoconductive layer by charging, lt-light, development and fixing on the photoconductor.

Inorganic compounds that are currently widely used as photoconductor elements for electrophotographic photoreceptors include amorphous selenium, cadmium sulfide, and zinc chloride. Although amorphous selenium has good properties as a photoconductor element, it is difficult to manufacture because it must be manufactured by vapor deposition, and the vapor-deposited film is not flexible.
The drawback is that it is highly toxic, requires careful handling, and is expensive. Cadmium sulfide and zinc oxide are used in the form of a photoconductive layer dispersed in a binder resin, and the weight ratio of wood/photoconductor element is between 0.2 and 0.
．． Practical sensitivity cannot be obtained unless it is 3 or less, so
It has shortcomings in mechanical properties such as flexibility, smoothness, hardness, tensile strength, and abrasion resistance. Therefore, it cannot withstand repeated use as it is. Hygiene issues with cadmium sulfide also need to be considered.

In recent years, electrophotographic photoreceptors using various organic materials have been proposed in order to eliminate the drawbacks of these inorganic materials, and some of them have been put into practical use.

For example, poly-N-vinylcarbazole and 2°4.7-
) dinitrofluoren-9-one (U.S. Pat. No. 3,484,237), poly-N-vinylcarbazole sensitized with pyrylium salt dye (Japanese Patent Publication No. 4
B-25658), a photoreceptor whose main component is a eutectic complex consisting of a dye and a resin (Japanese Unexamined Patent Publication No. 10735/1983), and the like.

Furthermore, an electrophotographic photoreceptor has been proposed that combines a substance that generates electric charge when exposed to light (called a charge-generating substance) and a substance that can transport the generated electric charge (called a charge-transporting substance). . For example, U.S. Patent No. 3.791.
826. No. 3 discloses a photoreceptor in which a charge transport layer is provided on a charge generation layer, and US Pat. No. 3,764,315 discloses a photoreceptor in which a charge generation material is dispersed in a charge transport material. The photoreceptor it has is listed.

Many of the substances generally known as charge-generating substances are azo dyes such as chlorodiane blue.

Or colored pigments such as phthalocyanine pigments,
Since these alone have low charge generation ability, they must be contained in large amounts in the photoreceptor in order to bring out the charge generation ability to a level of practical sensitivity.

However, when such a large amount of colored dye is contained, the mechanical strength of the photoreceptor is weakened, and from another point of view, it is due to the strong absorbance.

Since effective visible light does not sufficiently penetrate into the photosensitive layer, sufficient charges cannot be generated inside the photosensitive layer, resulting in a decrease in sensitivity. From this point of view,
In recent years, a highly sensitive photoreceptor has been proposed, as in US Pat. here.

Since there are few compounds that are excellent as charge-generating substances, at present, even more excellent photoreceptors are obtained by improving charge-transporting substances. However, such laminated photoreceptors are not only economically disadvantageous compared to single-layer photoreceptors from an industrial perspective, but also because they contain a large amount of charge-generating substance in the charge-generating layer for the reasons mentioned above. Since the thickness needs to be uniform, 5 microns or less, practically 1 micron or less, there is a technical problem. Furthermore, due to the large amount of charge-generating substance in the charge-generating layer, adhesion to the supporting substrate becomes insufficient, and mechanical strength also becomes a problem.

Furthermore, one charge generated at the interface between the charge generation layer and the charge transport layer is trapped.

Sensitivity changes often occur when used continuously.

For this reason, there are many technical problems in putting it into practical use, such as the need to further provide an intermediate layer, a subbing layer, etc.

Furthermore, most of the laminated photoconductors currently in practical use have N-type organic photoconductor elements, so they are used as negative charging types to achieve high sensitivity when negatively charged, but corona discharge Compared to positive charging, the amount of ozone generated during corona discharge is approximately 10 times greater when negatively charged due to continuous use.

Ozone concentration increases in the room where the product is used, and the smell is all that is present, which poses a problem in terms of quality of life. Furthermore, the ozone generated in the photoreceptor also causes deterioration, resulting in a shortened lifespan.

Furthermore, in the case of phthalocyanine as a P-type semiconductor.

When used with positive charging, it does not have sufficient sensitivity by itself, and when a sensitizer such as TNF is further used, when exposed to tt light during the charging-exposure-development process, Since there is an induction period, usually called an inductance, until the charge on the surface of the photoreceptor decays, it is difficult to adjust the timing during development, and an image with clear contrast can be obtained.

It has the disadvantage that only me with poor gradation can be obtained,
There was still room for improvement.

Furthermore, even in a photoreceptor having a photosensitive layer containing a charge-generating substance and a charge-transporting substance, conventional charge-generating substances have a sensitivity of 2.
As a result of conducting research on 9vA for the purpose of gradation, repeating characteristics, etc., it was found that a layer containing a specific phthalocyanine composition (A) further contained 9vA.

By incorporating a charge transport substance (B).

When positively charged, there is no inductilon phenomenon.

High sensitivity, excellent stability with repeated use, and no scratches on the photoreceptor appearing on the copy.

They discovered that it is possible to obtain an electrophotographic photoreceptor that is not easily affected by generated ozone, has excellent image gradation reproducibility, is inexpensive, and has excellent hygiene.

The present invention has been achieved.

The specific phthalocyanine composition (A) in the present invention refers to phthalocyanine and a benzene nucleus of the phthalocyanine molecule formed by at least one electron-withdrawing group selected from a nitro group, a cyano group, a halogen atom, a sulfone group, and a carboxyl group. This is a phthalocyanine composition obtained by mixing a substituted phthalocyanine derivative with an inorganic acid capable of forming a salt with phthalocyanine, and then precipitating the mixture with water or a basic substance.

The phthalocyanine according to the present invention is metal-free phthalocyanine or metal phthalocyanine.

Or a mixture of these. Copper is the metal of metal phthalocyanine! I, beryllium, magnesium, calcium, zinc, cadmium.

Barium, mercury, aluminum, gallium, indium, lanthanum, neodymium, samarium.

Europium, gadolinium, dysprosium, holmium, erbium, thulium, interbium, lutetium, titanium, tin, hafnium, lead, thorium, vanadium, antimony.

Chromium, molybdenum, uranium, manganese, iron.

Cobalt, nickel, rhodium, palladium.

These include osmium and platinum. Moreover, rather than a metal atom as the central nucleus of phthalocyanine.

It may be a metal halide having a valence of 3 or more. Metal-free phthalocyanines and metal phthalocyanines such as copper, cobalt, lead, and zinc are impressive. Furthermore, it may be a low halogenated phthalocyanine. Although phthalocyanine is a well-known compound as a pigment, in the present invention, phthalocyanine obtained by any manufacturing method may be used. Of course, a 5-pigmented phthalocyanine may also be used.

The phthalocyanine derivative according to the present invention is one in which the benzene nucleus of the phthalocyanine molecule is replaced with W by at least 141 electron-withdrawing groups selected from nitro groups, cyano groups, halogen atoms, sulfone groups and carboxyl groups.

This phthalocyanine derivative is used during phthalocyanine synthesis.
It can be obtained by using phthalonitrile, phthalic acid, phthalic anhydride, or phthalimide substituted with the above-mentioned substituents as the raw material for phthalocyanine, or by using some of them in combination. In particular, ulli! is a method for producing phthalocyanine derivatives. Not done. Further, the number of substituents in one molecule of the phthalocyanine derivative is 1 to 16, preferably 1 to 8, and more preferably 1 to 4. The number of substituents varies depending on the 1M manufacturing method, but in many cases different numbers of substituents are mixed. In addition, as the phthalocyanine derivative, for example, one having a nitro group and a cyano group, a phthalocyanine derivative having a nitro group, and a phthalocyanine derivative having a cyano group may be used in combination. Furthermore, some phthalocyanine derivatives other than the phthalocyanine derivatives of the present invention can also be used in combination.

In addition, phthalocyanine derivatives include metal-free phthalocyanine or copper, nickel, cobalt,
Metal phthalocyanines such as iron, sodium, lithium, calcium, magnesium, and aluminum. The composition ratio of phthalocyanine and phthalocyanine derivative is 100f of phthalocyanine! The amount of the phthalocyanine derivative is 0.01 to 20 parts by weight. Preferably, the amount of the phthalocyanine derivative is 0.1 to 5 parts by weight. If it is less than 0.01 parts by weight, sufficient sensitivity cannot be obtained, and if it exceeds 20 parts by weight, the dark decay rate increases and it cannot be put to practical use.

Next, one representative example of the method for producing phthalocyanine and phthalocyanine derivatives will be given. First, the nitrile is heated in an organic solvent such as an alcohol with a strong base catalyst such as ammonia alcoholade in the presence or absence of a phthalodinitrile and/or a phthalodinitrile substituted with a nitro group or a cyano group and a metal salt. method, phthalic anhydride and or phthalic anhydride substituted with nitro or cyano groups, urea, metal salts with molybdic acid,
There is a method of heating in the presence or absence of a solvent using ammonium or the like as a catalyst. Alternatively, a method using aminoiminoisoindolenine or the like may be used.

Examples of inorganic acids that can form salts with the phthalocyanine used in the present invention include sulfuric acid, orthophosphoric acid, birophosphoric acid, chlorosulfonic acid, hydrochloric acid, hydroiodic acid, hydrofluoric acid, and hydrobromic acid. These inorganic acids are those used in conventionally known methods such as phthalocyanine acid pasting method and acid slurry method. Further, as a method, a conventionally known method is applied. for example.

A method of dissolving phthalocyanine in the above inorganic acid and then injecting the solution into water etc. (acid pasting method),
There is a method in which a slurry of an inorganic acid salt of phthalocyanine is made and injected into water etc. (acid slurry method), or a method in which the inorganic acid salt of phthalocyanine is decomposed with a basic substance such as ammonia gas to precipitate phthalocyanine.

Furthermore, in the present invention, the charge transporting substance (B) to be mixed into the layer containing the phthalocyanine composition may include hitherto known hydrazone compounds, pyrazoline compounds, oxadiazole compounds, triphenylamine compounds, etc. charge transport materials can be used. Hydrazone compounds can usually be obtained by condensing a hydrazine derivative with an aldebide component or a ketone component. Specific examples of hydrazone compounds include the following compounds. P-N-dimethylaminobenzaldehyde-N-phenylhydrazone), P-N-diethylaminobenzaldehyde-N-
phenylhydrazone), P-N-diethylaminobenzaldehyde-N,N-diphenylhydrazone), 3-
(N-diphenylhydrazone)-methyl-9-ethylcarbazole, 3-(N-methyl-N-phenylhydrazone)-methyl-9-ethylcarbazole, 3-(N-phenylhydrazone)-methyl-9-ethylcarbazole,
P-N-diethylaminobenzaldehyde-N,N-ethyl-phenylhydrazone, P-N-diethylaminobenzaldehyde-N,N-methyl-phenylhydrazone, 6-N,N-diethylaminobenzothiazole-2-
Examples include carbaldevido N, N-diphenylhydrazone, and the like.

In addition, oxadiazole compounds are usually 1.

Between a compound having a carboxyl group and a hydrazine compound or hydrazidation compound.

Obtained by dehydration and ring closure using polyphosphoric acid or the like. Among many of these oxadiazole compounds, specific examples include 2.5-bis-(4-dimethylaminophenyl 1)-1,3,4-oxadiazole; 5-bis-(4-di-n-propyl)-amino-phenyl 1-1.3,4. -Oxadiazole.

2.5-bis-(4-diethylaminophenyl-1-)
-1,3,4-oxadiazole, 2,5-bis-(
4-acetylamino-2-chlorophenyl-1)-1,
3,4-oxadiazole, 2,5-bis-(4-n-
Propylaminophenyl-1)-1,3,4-oxadiazole, 2,5-bis-(4-(n-pro-ruamino)-2-chlorophenyl-1)-1,,3゜4-oxa Diazole, 2,5-bis-(4-cyclohexylaminophenyl-1)-1,3,4-oxadiazole, 2
,5-bis-(4-diethylaminostyryl)-1,3
, 4-oxadiazole and the like.

Specific examples of pyrazoline compounds include:

[1-phenyl-3-(p-diethylaminostyryl)
-5-(p-diethylaminophenyl)-2-pyrazoline], ■, 5-defenyl-3-methyl-pyrazoline, 1,3,5-triphenylpyrazoline, 1-(β)-
Naphthyl-3,5-diphenyl-pyrazoline, 1,5-
Diphenyl-3-p-oxyphenyl-pyrazoline, ■
・3-diphenyl-5-p-methoxyphenyl-pyrazoline, 1-p-ethoxyphenyl-3,5-diphenyl-pyrazoline, l-m-tolyl-3,5-diphenyl-
Pyrazoline.

1-p-tolyl-3,5-diphenyl-pyrazoline, 1
-phenyl-3-p-methoxy-styryl-5-1-p
-methoxy-phenyl-pyrazoline, 1-phenyl-3
-p-dimethylaminostyryl-5-p-dimethylamino-phenyl-pyrazoline, 1-p-nitrophenyl-
Examples include 3-styryl-5-phenyl-pyrazoline, 1.3-diphenyl-5-(p-dimethylamino)-phenyl-pyrazoline, and 1.5-diphenyl-3-styryl-pyrazoline. Further, specific examples of triphenylamine compositions include triphenylamine,
Tri(P-methylphenyl)amine and the like can be mentioned.

Since the phthalocyanine composition and the charge transport substance in the present invention usually do not have film-forming ability by themselves, a binder resin is used to form the photosensitive layer. However, the binder may not be used in cases where the charge transport substance has a film-forming ability or when a protective layer is formed on the photosensitive layer. The binder preferably used in the present invention is a highly electrically insulating film-forming polymer or copolymer. Such polymers and copolymers are preferably used as binders in the present invention, such as phenol resins, polyester resins, 5-vinyl acetate resins, polycarbonate resins, polypeptide resins, cellulose resins, polyvinylpyrrolidone, and polyethylene oxide. ,
Polyvinyl chloride resin, starch, polyvinyl alcohol, acrylic copolymer resin, methacrylic copolymer resin,
silicone resin, polyacrylonitrile copolymer resin,
Examples include polyacrylamide, polyvinyl butyral, polyvinyl carbazole, polyvinylidene chloride resin, and the like. These polymer binders can be used alone or with 24f
Although one or more binders can be used as a mixture, the binders that can be used in the present invention are not limited to these.

In order to use the composition according to the present invention as an electrophotographic photoreceptor, the composition is uniformly dispersed together with a binder resin, a solvent, etc. using a mixed wire dispersion machine such as a ball mill or attritor, and then spread onto a conductive support. Coating to form a photosensitive layer. As for the application method.

If necessary, add a solvent to the leading composition to adjust the viscosity;
Air doctor coater, blade coater, rod coater, reverse roll coater, spray coater,
The film is formed using a coating method such as a bot coater or spray coater. After coating, drying is performed using an appropriate drying device until a sufficient charging potential is applied to the photoconductive layer.Additives commonly used in the photosensitive layer may be used as necessary. You can also do it.

In addition, the phthalocyanine composition for the binder in the present invention is 5 to 70 parts by weight based on 100 parts by weight of the binder.
Preferably it is 20 to 60 parts by weight. In addition, the charge transport material is 10 parts by weight per 100 parts by weight of the binder.
~300 parts by weight is preferred. However, the present invention is not limited only to this range. The thickness of this photosensitive layer is determined by the required photosensitivity and durability as well as the mixing ratio of the phthalocyanine composition and the charge transport material to the binder, but is preferably 50 microns or less, particularly 1 micron to 30 microns. 9. Micron is preferable; if it is larger than this, the film will lose its flexibility. Particularly in the case of a belt-shaped photoreceptor, it may cause cracks and the like. The photosensitive layer can also be coated with a layer that serves as a protective layer, if necessary.

The support used in the electrophotographic photoreceptor of the present invention may be any support as long as it is endowed with conductivity, and any type of conductive layer conventionally used may be used. Specifically, metals such as aluminum, copper, stainless steel, and brass, plastics in which aluminum, indium oxide, tin oxide, etc. are vapor-deposited or laminated, or conductive particles 3 such as carbon black, 6m particles, and plastics in which aluminum particles are dispersed are used. can be mentioned. Also, regarding its shape, 1. It may be sheet-shaped, cylinder-shaped, or other shapes.

Note that when using the electrophotographic photoreceptor according to the present invention, the light source may be a normal halogen lamp or the like.

Because it has a sensitivity of 750 nm or more, it has a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength of 780 nm).
It is also possible to use a laser beam such as m).

The electrophotographic photoreceptor according to the present invention has no hygiene problems, and when used, since it is positively charged, it generates less ozone, has high sensitivity, has low inductance, and has a light attenuation curve. Since it has 5 curves, it has excellent 9-gradation performance in two-image reproduction, and there is little deterioration of the photoreceptor due to repeated use.Also, in practical use, the scratches will not appear on the copied image. Furthermore, even a single layer type has sufficient characteristics for practical use.

It has excellent practical characteristics such as being easy to manufacture and inexpensive.

The present invention will be explained below by giving one example. In the examples, "parts" indicate parts by weight.

Example 1 40 parts of copper phthalocyanine and 0.5 parts of tetranitrocopper phthalocyanine are dissolved in 500 parts of 98% concentrated sulfuric acid with thorough stirring. The dissolved solution is poured into 5000 parts of water to precipitate a composition of copper phthalocyanine and tetranitrocopper phthalocyanine, followed by filtration, washing with water, and drying at 120° C. under reduced pressure.

Next, 1 part of this composition, 2.5 parts of P-N-diethylaminobenzaldebido N, N-diphenylhydrazone,
3.6 parts of acrylic polyol (manufactured by Yayoi Yakuhin Kogyo 01, Takelac A-702).

Epoxy resin (manufactured by Shell Chemical Co., Ltd., Epon 1007) 0.
A composition consisting of 5 parts of methyl ethyl ketone, 1.2 parts of methyl ethyl ketone, and 1.2 parts of cellosolve acetate was milled for 48 hours in a magnetic ball mill to obtain a photoconductive composition.

Next, this photoconductive composition was roll coated onto the aluminum of a laminate film of 5 micron thick aluminum foil and 75 micron polyester film to a dry film thickness of 8 microns, and uniformly heated to 110°C. The sample was placed in a heated oven for 1 hour to prepare an electrophotographic photoreceptor.

+5.7 K V for the sample thus obtained,
Corona gap 10 n+n+, 10 m/min
Corona discharge was applied at a charging speed of 10
After 2854 seconds, exposure is performed using a tungsten light source with an illuminance of 10 Lu. The amount of light irradiation required for the potential immediately before exposure to decrease by 50% at this time was defined as the sensitivity. The sample measured in this way had a maximum surface charge of 620V, a dark decay rate of 17%, and a sensitivity of 1. OL, ux, sec, residual potential 20
V, both chargeability and sensitivity are sufficient for practical use,
The optical attenuation curve (solid line) is shown in FIG. As seen in FIG. 1, no indulosis 1 was observed in the 2-surface pattern attenuation ζ during charging exposure, and a 5-curve light attenuation curve was shown. In addition, this photoconductor was positively charged with a copying machine to 10,000
I made several copies in succession, and the resulting images had excellent gradation. 1 Even when copying an ordinary photograph as an original, a beautiful image was obtained in terms of detail and intermediate color density.
There was no change in sensitivity, and although there were scratches on the photoreceptor, a clear image without any scratches was obtained in the copied image.

Example 2 40 parts of copper phthalocyanine and 1.5 parts of dinitrometal-free phthalocyanine are dissolved in 100 parts of 98% concentrated sulfuric acid with thorough stirring. Pour the dissolved liquid into 1000 parts of water,
After the phthalocyanine composition is precipitated, it is filtered once, washed with water, and dried at 120° C. under reduced pressure. 1 part of this composition, 1-
Phenyl-3(P-diethylaminostyryl)-5-(
P-diethylaminophenyl)-2A-pyrazoline (2 parts) was added to polycarbonate resin (Kijin a@Panlite L-12
50) Dispersion of 4 parts with 10 parts of tetrahydrofuran in a ball mill resulted in a large surface potential of 600 V, but a sensitivity of 20 Lux, sec, which was insufficient for practical use.

[Brief explanation of the drawing]

In Figure 1, the horizontal axis represents time (seconds) and the vertical axis represents surface potential. Patent representing a graph of light attenuation curve of a photosensitive layer Applicant: Toyo Ink Manufacturing Co., Ltd. No. 1 Ogiharuma (Ruy) Procedural Amendment (Spontaneous) September 1982) - 7th To the Commissioner of the Japan Patent Office 1, Indication of the case 1981 Patent Application No. 157911 2
, title of the invention Electrophotographic photoreceptor 3, "Detailed explanation of the invention" column 6 of the specification by the person making the amendment, content of the amendment 1, page 17, line 9, [What is to be done] isn't it. '', insert "9. Also, in the photosensitive layer according to the present invention, conventionally known ε-type crystalline phthalocyanine, β-type crystalline phthalocyanine, and photoconductor elements other than phthalocyanine can be used in combination." . 2. On page 17, line 15, "photoconductive composition" is corrected to "photoconductive composition."

Claims (1)

[Claims] (2) Forming a salt with phthalocyanine and a phthalocyanine derivative in which the benzene nucleus of the phthalocyanine molecule is substituted with at least one electron-withdrawing group selected from a nitro group, a cyano group, a halogen atom, a sulfone group, and a carboxyl group; The phthalocyanine composition (A) is mixed with the obtained inorganic acid and precipitated with water or a basic substance.
An electrophotographic photoreceptor comprising a photosensitive layer comprising B).