JPH03273258A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain photosensitivity adapted to semiconductor laser beams by using a combination of a specified electric charge generating material and a specified charge transfer material. CONSTITUTION:The charge generating material is an X-type metal-free phthalocycnine crystalline composition having characteristic absorptions in the regions of 971 + or -2 cm<-1> and 965 + or -2 cm<-1> but not in the regions of 980 + or -2 cm<-1> and 955+ or -2cm<-1> in the infrared absorption spectra, and strong diffrac tion peaks in the Bragg angles (2theta + or -0.2 deg.) of 7.5 deg., 9.1 deg., 16.7 deg., and 17.3 deg. in the X-ray diffraction spectra using CUKalpha as a light source, and the charge transfer material comprises as effective components the butadiene derivative represented by formula I and the oxadiazole compound represented by formula II, and in formulae I and II, each of R<1>-R<4> is alkyl; and each of R<5>-R<8> is H, alkyl, acyl, or the like, thus permitting photosensitivity adapted to semiconductor laser beams to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more particularly to a highly sensitive electrophotographic photoreceptor using a stable X-type metal-free phthalocyanine-containing composition.

[Prior art and its problems] Conventionally, phthalocyanines 1. Metal phthalocyanines are known to exhibit excellent photo-II conductivity, and some are used in electrophotographic photoreceptors. With the recent development of non-impact printer technology, electrophotographic optical printers that use laser light or LED as light sources and are capable of high image quality and high speed are becoming widespread, and the development of photoreceptors that can withstand these demands. is popular.

Especially when using a laser as a light source, it is small and inexpensive.

Semiconductor lasers are often used due to their simplicity, but the oscillation wavelength of the semiconductor lasers currently used for these is as follows:
It is limited to relatively long wavelengths in the near-infrared region. Therefore, it is inappropriate to use a photoreceptor sensitive to the visible region, which has been conventionally used in electrophotographic copiers, for semiconductor lasers, and a photoreceptor with photosensitivity extending into the near-infrared region is required. It has become to.

Conventionally known organic materials that meet this requirement include methine squaric acid dyes, indone-one dyes, cyanine dyes, biryllium dyes, bo-1-noazo dyes, phthalocyanine dyes, and naphthoquinone dyes. There is.

Among these, methine squaric acid dyes, indoline dyes, cyanine dyes, and biryllium dyes can be used for longer wavelengths, but they lack practical stability (repetitive properties).
Currently, polyazo dyes are difficult to produce with long wavelengths and are disadvantageous in terms of production, while naphthoquinone dyes have poor sensitivity.

On the other hand, phthalocyanine dyes have a peak spectral sensitivity in the long wavelength range of 600 nm or more, and are also highly sensitive.Since the spectral sensitivity changes depending on the central metal and the number of crystalline rods, dyes for semiconductor lasers. It is considered to be suitable for this purpose, and intensive research and development is being carried out.

Among the phthalocyanine compounds studied so far, 7
Examples of compounds that exhibit high sensitivity in a long wavelength range of 80 nm or more include X-type metal-free phthalocyanine, ε-type copper phthalocyanine, vanadyl phthalocyanine, and the like.

On the other hand, in order to increase sensitivity, a laminated photoreceptor with a vaporized phthalocyanine film as a charge generation layer was studied, and
Among the phthalocyanines having group a and group IV metals as their central metals, some have been obtained that have relatively high sensitivity. Documents related to such metal phthalocyanines include, for example, JP-A-57-211149, JP-A-57-148745, JP-A-59-36254, JP-A-59-44054, JP-A-59-30541, and JP-A-59. -31965 Publication, 59-166959
There are publications etc. However, the preparation of the vapor deposited film requires a high vacuum evacuation device, which increases the equipment cost, so the above-mentioned organic photoreceptor inevitably becomes expensive.

In contrast, phthalocyanine is not deposited as a film, but
A composite photoreceptor has also been considered, in which a resin dispersion layer is used as a charge generation layer, and a charge transport layer is applied thereon. 57-66963) and indium phthalocyanine (Japanese Patent Application No. 59-22cm-493), these are relatively highly sensitive photoreceptors;
The former has disadvantages such as a rapid decrease in sensitivity in the long wavelength region of 8 (10 nm or more), and the latter has insufficient sensitivity for practical use when the charge generation layer is made of a resin dispersion system. It has disadvantages such as:

In addition, phthalocyanines generally have crystal polymorphism, but in an aromatic solvent, they transform to the most stable crystal form, generally called a β-type crystal.

Therefore, crystals in an unstable state such as α type, X type, and ε type are
As shown in Japanese Patent No. 6300, etc., it is stabilized by adding a phthalocyanine derivative and put into practical use.

However, these derivatives not only have almost no photoconductivity, but also cause deterioration in all of the important electrophotographic properties such as photosensitivity, chargeability, and dark decay rate. This is presumed to be due to the addition of a side chain to the outer benzene ring of phthalocyanine, which shortens the intermolecular distance, increases conductivity in the direction of the molecular plane, and results in poor crystallinity.

In particular, U.S. Patent No. 3.357.989 with good photoconductive properties
The reason why the X-type metal-free phthalocyanine shown in No. (1967) cannot be put to practical use is because of the above-mentioned (1) instability of the crystal, (2) the accompanying difficulty in controlling the manufacturing process, and (3) the photoconductive spectrum of around 800 nm. 1: Generally, the oscillation wavelength fluctuates by about ±10nIl due to temperature etc.78
This is because, when applied to a photoreceptor for an optical printer using a semiconductor laser whose emission center is 0 nm as an exposure source, there is a problem in that sensitivity changes occur, which is inconvenient.

On the other hand, as charge transfer materials, various organic materials such as butadiene compounds and oxadiazole compounds have been proposed in recent years, and some of them have been put into practical use. However, among these, those containing a butadiene compound are strong against photo fatigue but have poor electrical properties, and those containing an oxadiazole compound have good electrical properties but have a problem with photo fatigue.

The present invention has been made in response to the conventional circumstances as described above, and provides an electrophotographic photoreceptor that combines organic photoconductive materials and has photosensitivity suitable for semiconductor lasers and whose characteristics can be controlled. The purpose is to provide

[Means for Solving the Problems] The present invention provides an electrophotographic photoreceptor comprising a charge generating material and a charge transporting material, wherein (a) the charge generating material contains 100 parts by weight or less of metal-free phthalocyanine and 100 parts by weight of titanyl phthalocyanine. A type X metal-free phthalocyanine composition crystal containing 971±2 cm-' and 9
It shows a characteristic absorption at 65±2c-1, and 980±2c''
1 and 955 ± 2 c "1 Ni" It is a composition crystal that does not show characteristic absorption, and in the X-ray diffraction spectrum using CuKδ as a radiation source, the Bragg angle (2θ ± 0.2 degrees) is 7.5 degrees. , 9.1 degrees.

An X-type metal-free phthalocyanine composition having strong diffraction peaks at 16.7 degrees and 17.3 degrees is used as an active ingredient, (b) the charge transfer material is a butadiene compound represented by the following general formula [I], and the following: The electrophotographic photoreceptor is characterized in that it contains an oxadiazole compound represented by the general formula [II] as an active ingredient.

(In the formula, R1-R4 represent an alkyl group, which may be the same or different.> R1-R4 represent an alkyl group, and may be the same or different.) According to the present invention, as a charge transfer material, The above general formula [II
] and the above general formula [II]
By using the oxadiazole compounds represented by A strong electrophotographic photoreceptor is also provided.

The present invention will be explained in detail below.

The metal-free phthalocyanine used in the present invention has the general formula;
X2, X3, and X4 each independently represent various halogen atoms, n, m,! , each independently represents a number from O to 4. 〉 It is a compound represented by

Among the metal-free phthalocyanines used in the present invention, particularly preferred are metal-free phthalocyanines, metal-free chlorophthalocyanines, and mixtures thereof.

These metal-free phthalocyanines can be obtained by any known method. For example, in Reinhold Publishing's Phthalocyanine Compounds J (1963), F. Moser (F, noser) and A. Thomas (A, T.
method for producing α-type and β-type metal-free phthalocyanine shown by
There is a method of synthesizing O-phthalodinitrile in an alcoholic solvent in the presence of a strong base catalyst as shown in the above publication.

The metal-free phthalocyanine thus obtained is treated with an acid,
Alkaline cleaning, alcohols such as methanol, ethanol, and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and 1,4-dioxane, 2-ethoxyethanol, quinoline, N, N-dimethylformamide, N - It is preferable to perform washing treatment with an electron-donating solvent such as methylpyrrolidone or pyridine.

X-type metal-free phthalocyanine is produced by using the above materials as
It can be obtained by crystallization according to the method shown in Publication No. -14106@, No. 46-42512, and the like.

In the present invention, X-type metal-free phthalocyanine obtained by any method can be used, but when used as a charge generating material for an electrophotographic photoreceptor, in order to obtain good dispersibility, it is necessary to mill to obtain one with a small particle size. Those obtained by the method are preferred.

Further, in order to obtain good photoelectric properties, it is preferable to use a well-cleaned α type obtained by an acid pasting method or a mechanical pulverization method as the milling raw material at that time.

The acid pasting method is a well-known chemical treatment method for obtaining α-type metal-free phthalocyanine.
This method involves dissolving the pigment in sulfuric acid or making it into an acid salt, pouring it into water or ice water, and re-precipitating it.
Fine particles can be obtained under even better conditions by keeping the acid and water preferably at 5° C. or lower and slowly injecting the acid into water that is stirred at high speed.

Other methods include a method in which crystalline particles are directly milled using a mechanical processing device for a very long time, and a method in which particles obtained by an acid pasting method are treated with the above-mentioned solvent or the like and then milled.

Stabilization of the X-type metal-free phthalocyanine by adding titanyl phthalocyanine is possible in various steps during the X-form production.

That is, in the following cases: ■ Adding in the normal β form (with some α forms mixed) after crude synthesis and purification, ■ Adding at the α form stage, ■ Adding during the transition to the X form, and ■ Adding to the X form. Both cases are possible, but in order to obtain a good X-type crystal, ■
Alternatively, ■ is practically preferable.

In particular, in the X-type production method using the milling method, stirring and purification using a solvent is performed in the final step, but in the conventional method, only aliphatic solvents can be used in consideration of β-ization of the crystals, and problems remain in terms of cleaning effectiveness. . At this time, if titanyl phthalocyanine is added, even if ester solvents or aromatic solvents with high purification efficiency are used, the X-form will not be converted to the β-form and will remain stable as the X-form, which has high purity and stability. It is preferable to be present at least in this step.

Therefore, the solvent used at this time can be freely selected from solvents with good dispersibility and solvents with excellent purification efficiency, such as ethers and esters such as tetrahydrofuran and dimethylformamide, ketones such as methyl ethyl ketone and acetone, and toluene. Examples include aromatics such as Aromatics, halogens such as methylene chloride, electron-donating solvents such as N-methylpyrrolidone, and the like.

The amount of titanyl phthalocyanine added is preferably 1 part by weight or less, particularly preferably 50 parts by weight or less, per 100 parts by weight of titanyl phthalocyanine. This is because the presence of a large amount of titanyl phthalocyanine during X-ray diffraction measurement to confirm the crystal type results in poor resolution, making it difficult to identify the crystal type.

The X-type metal-free phthalocyanine composition thus obtained has an infrared absorption spectrum of 971±2 on-
'965±2ctx-' exhibits characteristic absorption, 9
55±2cm'980±2cut-' shows no characteristic absorption. In contrast, the additive-free X-type metal-free phthalocyanine exhibits a characteristic absorption at 955±2αn-'. On the other hand, in the X-ray diffraction spectrum, the Bragg angle (2θ
±0.2 degrees> are 7.5 degrees, 9.1 degrees, and 16.7 degrees.

It shows a strong diffraction peak at 17.3 degrees and has X-type characteristics.

The titanyl phthalocyanine used in the present invention has the general formula; Represents a number from O to 4.> It is a compound represented by the following.

Among the titanyl phthalocyanines used in the present invention, particularly preferred titanyl phthalocyanines (Ti0Pc
> , titanylchlorophthalocyanine (Ti0PcCJ
and mixtures thereof.

These titanyl phthalocyanine compounds are, for example, 1
, 2-dicyanobenzene (○-phthalodinitrile) or a derivative thereof and a metal or metal compound according to a known method.

Purification and washing of the synthetic compound can be carried out in the same manner as in the case of the metal-free phthalocyanine described above.

In addition, the stability and bidispersity of the paint are important in the preparation of the paint necessary when producing an electrophotographic photoreceptor using a coating method.
For this purpose, it is preferable that the particles to be dispersed are minute. These titanyl phthalocyanines can be made into fine particles by a single chemical method, an i-mechanical method, or more preferably by a combination of various methods.

For example, extremely fine particles can be obtained by weakening the aggregation between particles using a method such as an acid pasting method or an acid slurry method, and then grinding the particles using a mechanical processing method. Equipment used during grinding includes a kneader, Banbury mixer, attritor, edge runner mill, roll mill, ball mill, sand mill, and 5PE.
X mill.

Homo mixer, disperser, agitator, show crusher, stamp mill, cutter mill.

Examples include, but are not limited to, micronizers. In addition, the acid pasting method, which is a well-known chemical treatment method, involves dissolving pigments in 95% or more @acid or using sulfuric acid! This method involves pouring the salt into water or ice water and re-precipitating it. However, by keeping sulfur #I and water preferably at 5°C or lower, and slowly injecting sulfuric acid into water that is being stirred at high speed, Fine particles can be obtained under good conditions.

Other methods include a method in which crystalline particles are directly milled using a mechanical processing device for a very long time, and a method in which particles obtained by an acid pasting method are treated with the above-mentioned solvent or the like and then milled.

The fine titanyl phthalocyanine particles obtained as described above are further purified and washed with various solvents. As the washing solvent, a solvent similar to that used for washing the phase composite product is appropriately used. In particular, those purified with tetrahydrofuran have good electrophotographic properties and good dispersibility, and are suitable for use in the present invention.

This is 9.7 degrees at the Bragg angle <2θ±0.2 degrees> when the X-ray diffraction spectrum uses Cukδ as the radiation source.

It has characteristic strong peaks at 24.1 degrees and 27.2 degrees (huge!).Titanyl phthalocyanine having various other known X-ray diffraction patterns can also be used as the X-type metal-free compound of the present invention. Both can be used to stabilize phthalocyanine crystals, and there is no difference in their stabilizing function.

An electrophotographic photoreceptor is produced using the stabilized X-type metal-free phthalocyanine composition obtained as described above.

A homogeneous and highly sensitive charge generation layer can be obtained by coating the X-type metal-free phthalocyanine composition of the present invention or the composition and a titanyl phthalocyanine compound together with a suitable resin as a charge generation material on a substrate. The mixing ratio of the X-type metal-free phthalocyanine composition and titanyl phthalocyanine can be changed as necessary.

When only type X is used, the peak of its spectral wavelength is 770
780 nm, which is the oscillation wavelength of a semiconductor laser.
At nm, the photosensitivity decreases.

On the other hand, titanyl phthalocyanine has a spectral sensitivity peak near 82 cm-nm, and 780 nm is not necessarily the highest sensitivity.

Figure 9 is a correlation diagram between the amount of titanyl phthalocyanine and the peak wavelength of spectral sensitivity for the X-type metal-free phthalocyanine composition. For example, a photoreceptor having a peak spectral sensitivity of 780 nI can be manufactured. Furthermore, since these two types of formulations have different physical properties such as specific resistance and work function, it is possible to adjust the injection efficiency of carriers from the substrate and into the charge transfer layer, which makes it possible to adjust the injection efficiency of carriers from the substrate and into the charge transfer layer. The photoreceptor characteristics required for each system can be finely adjusted, and a photoreceptor having an extremely wide range of practical suitability can be provided.

Form lli! by coating the charge generation layer! The resin that can be used in step 2 can be selected from a wide variety of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, poly[nylanthracene, and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin.

polyamide, polyvinylpyridine, cellulose resin,
Urethane resin, epoxy resin, silicone resin, polystyrene, polyketone, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polygonyl acetal, polyacrylonitrile, phenolic resin, melamine resin, casein,
Examples include insulating resins such as polyvinyl alcohol and polyvinylpyrrolidone. The resin contained in the charge generation layer is suitably 100% by weight or less, preferably 40% by weight or less. Further, these resins may be used alone or in combination of two or more.

The solvent for dissolving these resins varies depending on the type of resin, and it is preferable to select a solvent that does not affect the charge transfer layer or undercoat layer described later during coating. Specifically benzene and xylene.

Aromatic hydrocarbons such as ligroin, monochlorobenzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol, esters such as ethyl acetate and methyl cellosolve, carbon tetrachloride , aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, trichloroethylene, etc., tetra-10
Ethers such as furan, dioxane and ethylene glycol 7-methyl ether, amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and sulfoxides such as dimethylsulfoxide are used.

Coating is performed using a spin coater, applicator, spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, or dot coater, and drying is preferably done by heating for 40 minutes.
The test is carried out at 0 to 2 cm - 0° C. for 10 minutes to 6 hours under stationary or blowing air conditions.

After drying, the coating is applied so that the S thickness is 0.01 to 5 legs, preferably 0.1 to 1 leg.

One of the charge transfer materials used in the present invention has the general formula [
One is a butadiene compound represented by formula [I], and the other is an oxadiazole compound represented by general formula [II].

Examples of the butadiene compound of general formula [I] include the following compounds.

(Left below) H3 H3 [II,1-bis-(p-dimethylaminophenyl)
-4,4-diphenyl-1,3-butadiene c2)+5 [II,1-bis-(p-diethylaminophenyl)
-4,4-diphenyl-1,3-butadiene Further, examples of the oxadiazole compound of general formula [II] include the following compounds.

[2,5-bis-(4-dimethylaminophenyl)-1
,3,4-oxadiazoleco[2,5-bis-(4-isoamylaminophenyl)-
1゜3.4-oxadiazole] [2,5-bis-(4-diethylaminophenyl)-1
,3,4-oxadiazoleco...NJ) [2,5-bis-(4-cyclopentylaminophenyl>-1,3,4-oxadiazole]) [2,5-bis-(4-n -propylaminophenyl)
-1゜3.4-oxadiazole co...(h) [2,5-bis-(4-cyclohexylaminophenyl)-1,3,4-oxadiazole] [2,5-bis -(4-N-ethyl-N-n-propyl-aminophenyl)-1,3,4-oxadiazole]
[2,5-bis-(<4-di-n-propyl>-aminophenyl)-1,3,4-oxadiazole][2,5
-bis-(4-<N-ethyl-N-acetyl>-aminophenyl)-1,3,4-oxadiazole][2,
5-bis-(4-acetylaminophenyl)-1,3,
4-oxadiazole] [2,5-bis-(4-ethylaminophenyl)-1,
3,4-oxadiazole] [2-(4-diethyl-aminophenyl)-5-(4'
-dimethyl-aminophenyl) -1,3,4-oxadiazoleco -N υ [2-(4-mono-n-propyl-aminophenyl)-
5-(4“-dimethyl-aminophenyl)-1,3,4
-oxadiazole] [2-(4-7]-〇-propyl-aminophenyl)-
5-(4°-mono-ethyl-aminophenyl) -1,
3,4-oxadiazole] (Hereinafter in the margin) Among the above substances, butadiene compounds are particularly 1,1
-Dosu(p-diethylaminophenyl)-4,4-diphenyl-1,3-butadiene is preferred, and the oxadiazole compound is particularly 2,5-bis-(4-diethylaminophenyl)-1,3,4- Oxadiazole is preferred. These butadiene compounds and oxadiazole compounds are known prior to the filing of this application, and are each produced by conventional methods.

The charge transfer group of the electrophotographic photoreceptor of the present invention is represented by the general formula [
A photoconductive method in which the butadiene compound of formula [I] and the oxadiazole compound of the general formula [II1] are dissolved together with a resin (binder) in a suitable solvent, and if necessary absorbs light and generates a charge. A coating solution obtained by adding various additives such as a substance, a sensitizing agent, an electron-absorbing material, an anti-deterioration substance, or a plasticizer is applied onto a conductive substrate, dried, and usually has a thickness of 5 to 30 μm.
It can be produced by forming a photosensitive layer with a film thickness of s.

The mixing ratio of the butadiene compound and oxadiazole compound to the resin is 30 to 30 parts by weight based on 100 parts by weight of the resin.
0 parts by weight, preferably 50-2 cm-0 parts by weight.

Roughly speaking, the mixing ratio of the butadiene compound and the oxadiazole compound is 10 to 1000 parts by weight, preferably 30 to 150 parts by weight, per 100 parts by weight of the butadiene compound.

The resin used for this charge transfer layer is silicone resin,
Ketone resin, polymethyl methacrylate.

Polyvinyl chloride, acrylic resin polyarylate.

polyester, polycarbonate, polystyrene.

Acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral,
Insulating resins such as polyvinyl formal, polysulfone, bo-1-noacrylamide, polyamide, chlorinated rubber, and poly-N-vinylcarbazole.

Polyvinylanthracene, polyvinylpyrene, etc. are used. These resins may be used alone or in combination of two or more.

The charge transfer layer can be applied using a spin coater, applicator, spray coater, bar coater, dip coater,
The coating is carried out using a device such as a doctor blade, roller cola, curtain coater or bead coater, and the film thickness after drying is preferably 5 to 50 cm, preferably 10 to 2 cm.

In addition to these layers, an undercoat layer can be provided on the conductive substrate for the purpose of preventing deterioration of chargeability, improving adhesion, and the like. Nylon 6 is used as the undercoat layer.
, nylon 66, nylon 11°, nylon 610. Alcohol-soluble polyamides such as copolymerized nylon and alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymers, gelatin, polyurethane, polyvinyl butyral, and metal oxides such as aluminum oxide are used.

It is also effective to incorporate conductive particles such as metal oxides and carbon black into the resin.

WIA thickness of undercoat layer is 0.05-1011Il
, preferably about 0.2 to 3 degrees.

The electrophotographic photoreceptor of the present invention preferably has an undercoat layer, a charge generation layer, and a charge transfer layer laminated in this order on a conductive substrate. It may be one in which a charge generating material and a charge transporting material are dispersed and coated on an undercoat layer with a suitable resin. Furthermore, these undercoat layers can be omitted if necessary.

The electrophotographic photoreceptor of the present invention has an absorption peak at a wavelength of around 800 parts m, and can be used as an electrophotographic photoreceptor in a copying machine.

In addition to being used in printers, solar cells.

It is also suitable as an absorbing material for photoelectric conversion elements and optical disks.

[Examples] The present invention will be specifically described below, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In the examples, "department" means "department" unless otherwise specified.
Parts by weight.

Production Example 1 100 parts of 0-phthalodinitrile (manufactured by BASF) and 10 parts of piperidine were stirred and reacted in 300 parts of chlordolol at 2 cm-0°C for 10 hours to obtain reddish-purple crystals. After further washing with acid and alkali, methanol,
Washing and purification was performed with N,N-dimethylformamide and N-methylpyrrolidone, followed by drying to obtain a pigment powder. As a result of IR spectrum and mass spectrometry, it was confirmed that it was a metal-free phthalocyanine.

Production Example 2 One part of the metal-free phthalocyanine obtained in Production Example 1 was cooled to 0 to 5°C. fiAM (concentration of 95 parts) was sufficiently dissolved in 2 cm-part of water, and the solution was added dropwise to 2 cm-0 part of water for reprecipitation. Filter this and add alkali hamethethanol.

Washing and purification was performed with N,N-dimethylformamide and N-methylpyrrolidone, followed by drying to obtain pigment flakes. X
According to line diffraction, it was α-type metal-free phthalocyanine.

Production Example 3 0-phthalodinitrile 2cm-. 4 parts, titanium tetrachloride 7
．． After reacting 6 parts in 50 parts of quinoline at 2 cm-0°C for 2 hours, the solvent was removed by steam distillation, and 2% aqueous hydrochloric acid solution,
Subsequently, the product was purified with a 2% aqueous sodium hydroxide solution, washed with acetone and N-methylpyrrolidone, and then dried to obtain 21.3 parts of titanyl phthalocyanine (TiOPc). The X-ray diffraction pattern after washing with water is shown in FIG. 3, and the X-ray diffraction pattern after washing with solvent is shown in FIG. 4.

Production Example 4 Two parts of the titanyl phthalocyanine obtained in Production Example 3 were heated to 90°C at 5°C.
It is gradually dissolved in 40 parts of 8% sulfur, and the mixture is stirred for about 1 hour while maintaining the temperature below 5°C.

Subsequently, the sulfuric acid solution was slowly poured into 400 parts of ice water that was stirred at high speed, and the precipitated crystals were filtered. The crystals were washed with distilled water until no acid remained, yielding 1.8 parts of amorphous titanyl phthalocyanine. The X-ray diffraction pattern of the product is shown in FIG.

Production Example 5 2 parts of the amorphous titanyl phthalocyanine obtained in Production Example 4 was stirred in 100 parts of tetrahydrofuran for about 5 hours.

It is then filtered and washed with tetrahydrofuran.
After drying, 1.7 parts of titanyl phthalocyanine were obtained. The X-ray diffraction pattern of the product thus obtained showed a crystalline form as shown in FIG.

Example 1 10 parts of α-type metal-free phthalocyanine obtained in Production Example 2 and 1 part of X-type metal-free phthalocyanine were stirred for 4 days in an FA ball mill. After confirming that the mixture had almost transformed into the X-form by X-ray diffraction, 1 part of titanyl phthalocyanine obtained in Production Example 5 and 2 cm -0 parts of tetrahydrofuran were added, and after further stirring for 5 hours, X-ray diffraction was performed. 10.5 parts of an X-type metal-free phthalocyanine composition with good crystallinity was obtained. Its infrared absorption spectrum is shown in FIG. 1, and its X-ray diffraction diagram is shown in FIG.

After that, filtration and drying are performed, and 1 part of this X-type metal-free phthalocyanine composition and butyral resin (manufactured by Block Chemical Co., Ltd.:
BX-1>1 part and 35 g of tetrahydrofuran were kneaded in a ball mill for 10 hours to obtain a paint.

This is made of polyamide resin (manufactured by Toshisha; CH-8000)
A charge generation layer was obtained by coating an aluminum substrate to a thickness of 0.37 parts on an aluminum substrate coated with 0.5 g of .

Roughly, 70 parts of 1,1-bis-(p-diethylaminophenyl)-4゜4-diphenyl-1,3-butadiene, which is the butadiene compound (b) of the general formula [I], and 70 parts of the butadiene compound (b) of the general formula [I]
2,5- which is the oxadiazole compound (d) of [II]
Bis-(4-diethylaminophenyl)-1,3,4-
30 parts of oxadiazole, polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.: Z-2cm-0) ioog and 2
5 parts of 4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-L3,5-triazine was dissolved in toluene/tetrahydrofuran (1/1
) The solution dissolved in 500 parts of the mixed solution has a dry film thickness of 15 μs.
A charge transfer layer was obtained by applying the following coating.

In this way, an electrophotographic photoreceptor having a laminated photosensitive layer was obtained. The half-decreased exposure (E1/2) of this photoreceptor was measured using an electrostatic copying paper tester N (Kawaguchi Electric Seisakusho EPA-8100). That is, it is charged by a corona discharge of -5.5 kV in a dark place, then exposed to white light with an illuminance of 5 lux, and the exposure amount E required to attenuate to half the surface potential is
(1ux-sec>72 was determined. The results are shown in Table-1.

Example 2 The oxadiazole compound ((1
), 2.5- of oxadiazole compound (f)
Bis-(4-isoamylaminophenyl)-1,3,4
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that -oxadiazole was used.

Example 3 In place of the oxadiazole compound (d) used in Example 1, 2,5-bis- of the oxadiazole compound (i) was used.
(<4-di-n-propyl>-aminophenyl)-1,
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that 3,4-oxadiazole was used.

Example 4 In the same manner as in Example 1, a type X metal-free phthalocyanine composition was prepared, and without removing the pigment or drying it, a butyral resin (BX-1 manufactured by Block Chemical Co., Ltd.) was placed in a rough ball mill.
> Add 10 parts and stir for 10 hours to prepare a paint. Similar to Example 1, 0.2# of the same paint was applied onto an aluminum substrate coated with polyamide resin.

Furthermore, 1,1-bis-(p) of butadiene compound (b)
-diethylaminophenyl)-4,4-diphenyl-1
12 cm parts of 3-butadiene, 30 parts of 2,5-bis-(4-diethylaminophenyl)-L34-oxadiazole of oxadiazole compound (d), polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.: 7-2 cm-0 ＞
100 parts, 3 parts of 2-hydroxy-4-methoxybenzophenone and 2,4-bis-(n-octylthio)-
3 parts of 6-(4-hydroxy-3,5-di-butylanilino)-L3,5-triazine was dissolved in 50 parts of dichloromethane.
A charge transfer layer was formed in the same manner as in Example 1 using a solution dissolved in 0 parts, and an electrophotographic photoreceptor was produced.

Example 5 A charge generation layer was prepared in the same manner as in Example 1 using 0.7 part of X-type metal-free phthalocyanine produced in the same manner as in Example 1 and 0.3 part of titanyl phthalocyanine obtained in Production Example 5. After forming, an electrophotographic photoreceptor was produced in the same manner as in Example 4.

Example 6 10 parts of α-type metal-free phthalocyanine obtained in Production Example 2, 0.5 parts of X-type metal-free phthalocyanine, and 2 parts of titanyl phthalocyanine obtained in Production Example 5 were stirred in a ball mill for 5 days and taken out, and methyl ethyl ketone was extracted. A slurry was prepared at 500 parts and purified.

The X-ray diffraction pattern of this product is shown in FIG. Next, an electrophotographic photoreceptor was produced in the same manner as in Example 4 except that the product was used.

Example 7 10 parts of metal-free phthalocyanine obtained in Production Example 1 and Production Example 5
0.5 part of the titanyl phthalocyanine obtained was treated with sulfuric acid in the same manner as in Production Example 2, then stirred in a ball mill for 7 days, and then solvent treated with toluene to obtain an X-type metal-free phthalocyanine composition. Obtained. The X-ray diffraction pattern of the product is
As shown in the figure. An electrophotographic photoreceptor was produced in the same manner as in Example 4, except that the product was used.

Comparative Example 1 A butadiene compound (
b) 100 parts, polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.: Z-2cm-0> and toluene/THF (
1/1) An electrophotographic photoreceptor coated with a paint consisting of 500 parts of the mixed solution was prepared.

Comparative Example 2 An electrophotographic photoreceptor was prepared in Comparative Example 1 using an oxadiazole compound (d) instead of the butadiene compound (b).

The characteristics of the electrophotographic photoreceptors prepared in Examples 1 to 7 and Comparative Examples 1 to 2 were investigated as described in Example 1, and the results are shown in Table 1.

(Left below) -732゜o2 surface potential (-5,5kV) E1/2' half-decreased exposure amount DDRI: Initial dark decay rate Dark decay rate =〈Surface potential after 2 seconds of charging〉 / (Initial surface Potential) In addition, the X-type metal-free phthalocyanine composition used in the present invention can stably secure the X-type metal-free phthalocyanine, which originally had poor crystal stability against solvents, heat, etc. and was difficult to obtain stable crystals. The titanyl phthalocyanine used as a stabilizer also has good electrical properties, so it is a stable composition with extremely excellent properties.

Further, by changing the composition ratio of stable X-type metal-free phthalocyanine and titanyl phthalocyanine, each having different characteristics, the photoreceptor characteristics can be adjusted, so it is possible to provide an electrophotographic photoreceptor optimal for the apparatus.

Furthermore, by combining the above-mentioned charge generation material and a charge transfer material containing two components of a butadiene compound and an oxadiazole compound, it is possible to provide an excellent electrophotographic photoreceptor with little variation in characteristic deterioration even after repeated use. .

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum diagram of the X-type metal-free phthalocyanine composition according to Example 1, and FIG.
An X-ray diffraction diagram of the type-free metal phthalocyanine composition, FIG. 3 is an X-ray diffraction diagram of titanyl phthalocyanine after water washing according to Production Example 3, and FIG. 4 is an X-ray diffraction diagram of titanyl phthalocyanine after solvent washing according to Production Example 3. , FIG. 5 is an X-ray diffraction diagram of titanyl phthalocyanine according to Production Example 4, FIG. 6 is an X-ray diffraction diagram of titanyl phthalocyanine according to Production Example 5, and FIG. 7 is an X-ray diffraction diagram of titanyl phthalocyanine according to Production Example 5.
ray diffraction diagram, Figure 8 is an X-ray diffraction diagram of the X-type metal-free phthalocyanine composition according to Example 7, and Figure 9 is a correlation diagram between the blending ratio of titanyl phthalocyanine to X-type metal-free phthalocyanine and the peak wavelength of spectral sensitivity. It is. Special feature 1' + Applicant NEC Corporation

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor including a charge-generating material and a charge-transfer material, (a) the charge-generating material is a type X-type metal-free phthalocyanine composition crystal containing 100 parts by weight or less of metal-free phthalocyanine and 100 parts by weight or less of titanyl phthalocyanine; In its infrared absorption spectrum, it shows characteristic absorption at 971±2cm^-^1 and 965±2cm^-^1, and 98
It is a composition crystal that does not show characteristic absorption at 0 ± 2 cm^-^1 and 955 ± 2 cm^-^1, and CuK
In the X-ray diffraction spectrum using @α@ as the radiation source, the Bragg angle (2θ ± 0.2 degrees) is 7.5 degrees, 9.1 degrees, 1
X with strong diffraction peaks at 6.7 degrees and 17.3 degrees
a type-free metal phthalocyanine composition as an active ingredient; An electrophotographic photoreceptor characterized by comprising: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, R^1 to R^4 represent alkyl groups, and may be the same or different.) ▲Mathical formulas, chemical formulas, There are tables, etc.▼...[II] (In the formula, R^5, R^6, R^7 and R^8 represent a hydrogen atom, an alkyl group, an acyl group or a cycloalkyl group, and may be the same as each other. may be different.)