JPS63168657A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body which is optimum as a photosensitive body for semiconductor laser and is adequate particularly for use with positive electric charge by incorporating specific nonmetallic phthalocyanine and compd. into a layer contg. a carrier generating material and binder material. CONSTITUTION:The photosensitive body having the layer contg. the carrier generating material and the binder material contains the nonmetallic phthalocyanine in which the main peaks of the Bragg angle 2theta to the characteristic X-ray (1.541Angstrom wavelength) of CuKalpha exist at least at 7.5 deg.+ or -0.2 deg., 9.1 deg.+ or -0.2 deg., 16.7 deg.+ or -0.2 deg., 17.3 deg.+ or -0.2 deg., and 22.3 deg.+ or -0.2 deg. in the above-mentioned layer and contains further the compd. expressed by the formula in said layer. In the formula, R<1> and R<2> denote a hydrogen atom or halogen atom, R<3> and R<4> denote a substd. or unsubstd. aryl group, Ar<1> denotes a substd. or unsubstd. arylene group. The photosensitive body which has the sufficient sensitivity to light of relatively long wavelengths such as semiconductor laser light and can be operated with the positive electric charge is thereby obtd.

Description

[Detailed description of the invention] B. Industrial application field The present invention relates to photoreceptors, such as electrophotographic photoreceptors.

BACKGROUND OF THE INVENTION Conventionally, electrophotographic photoreceptors sensitive to visible light have been widely used in copying machines, printers, and the like.

As such electrophotographic photoreceptors, inorganic photoreceptors provided with a photosensitive layer mainly composed of an inorganic photoconductive substance such as selenium, zinc oxide, or cadmium sulfide are widely used.
However, such inorganic photoreceptors do not necessarily satisfy the characteristics such as photosensitivity, thermal stability, moisture resistance, and durability required of electrophotographic photoreceptors for copying machines and the like.

For example, -selenium crystallizes due to heat or fingerprint stains when touched, so that the above-mentioned characteristics as an electrophotographic photoreceptor are likely to deteriorate. Further, electrophotographic photoreceptors using cadmium sulfide have poor humidity resistance and durability, and electrophotographic photoreceptors using zinc oxide have problems in durability. Further, electrophotographic photoreceptors made of selenium and cadmium sulfide both have toxicity, and have the drawback of being subject to significant restrictions in manufacturing and handling.

In order to overcome these problems with inorganic photoconductive materials, attempts have been made to use various organic photoconductive materials in the photosensitive layer of electrophotographic photoreceptors, and active research and development has been conducted in recent years. ing. For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N vinylcarbazole and 2,4,7-dolinitro-9-fluorenone. However, this photoreceptor also has insufficient sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with high sensitivity and durability by assigning the carrier generation function and carrier transport function to different substances in the photosensitive layer. ing.

In such so-called function-separated type electrophotographic photoreceptors, substances that exhibit each function can be selected from a wide range of materials, so it is relatively easy to obtain an electrophotographic photoreceptor with arbitrary characteristics. .

Therefore, it is expected that an organic photoreceptor with high sensitivity (and durability) can be obtained.

Many substances have been proposed as carrier-generating substances effective for the carrier-generating layer of such functionally separated electrophotographic photoreceptors. Examples of using inorganic substances include:
For example, amorphous selenium is mentioned as described in Japanese Patent Publication No. 43-16198. This carrier generation layer containing amorphous selenium is used in combination with a carrier transport layer containing an organic carrier transport material.
However, as described above, this carrier generation layer made of amorphous selenium has the problem that it is crystallized by heat or the like and its properties deteriorate.

Furthermore, examples of using an organic substance as the carrier generating substance include organic dyes and organic pigments. For example, those having a photosensitive layer containing a bisazo compound are disclosed in JP-A-47-37543 and JP-A-55-2.
This method is already known from Japanese Patent Application Laid-open No. 2834, Japanese Patent Application Laid-open No. 54-79632, Japanese Patent Application Laid-open No. 116040-1984, and the like. However, although these known bisazo compounds exhibit relatively good sensitivity in the short or medium wavelength range, their sensitivity in the long wavelength range is low, making them difficult to use in laser printers that use semiconductor laser light sources, which are expected to be highly reliable. That was difficult.

Gallium-aluminum-arsenic (Ga-Al-As) light-emitting elements, which are currently widely used as semiconductor lasers, have an oscillation wavelength of approximately 750 nm or more. Many studies have been made in the past in order to obtain electrophotographic photoreceptors that are highly sensitive to such long wavelength light. For example, it has been considered to add a sensitizer to photosensitive materials such as selenium and cadmium sulfide, which have high sensitivity in the visible light region, to extend the wavelength to a longer wavelength. Environmental resistance against temperature, humidity, etc. is not sufficient,
It is also toxic and has problems in practical use. Furthermore, as described above, the sensitivity of many known organic photoconductive materials is usually limited to the visible light region of 700 nm or less, and as a result, there are few materials that have sufficient sensitivity in the long wavelength region.

Among these, phthalocyanine compounds, which are one of the organic photoconductive materials, are known to have a photosensitive range extended to longer wavelength regions than other compounds. Various crystalline forms of phthalocyanine have been discovered in the process of converting α-type phthalocyanine into stable crystalline β-type phthalocyanine. Examples of these phthalocyanine compounds exhibiting photo-R'R properties include the X-type metal-free phthalocyanine described in Japanese Patent Publication No. 4338/1983.

Although this X-type metal-free phthalocyanine has sensitivity in a long wavelength region and has superior properties compared to other crystalline metal-free phthalocyanines, it is still insufficient.

Moreover, as a phthalocyanine compound, for example, JP-A-58-182639 f[! Examples include the τ-type metal-free phthalocyanine described in 4. As shown in Fig. 14, this τ-type metal-free phthalocyanine is produced by CuKa characteristic X-rays (wavelength: 1.541)
It is written as Kα (1,541 people). ), the black angle 2θ is 7.6 degrees, 9.2 degrees, 16.8 degrees, 17.4 degrees,
It has peaks at 20.4 degrees and 20.9 degrees, respectively.

In addition, in the infrared absorption spectrum, 700 to 760 cm
-', there are four absorption bands with the strongest intensity at 752±2cm-', two absorption bands with almost the same intensity between 1320 and 1340cm-', and a characteristic absorption band at 3288±2cm-'. be. However, this τ-type metal-free phthalocyanine is
Type-free metal phthalocyanine is heated at 50 to 180°C with a grinding aid such as salt and an inert organic solvent such as ethylene glycol.
The manufacturing method is complicated and difficult, as it is preferably manufactured by drying at 60 to 130° C. for 5 to 20 hours. Therefore, it is not always possible to obtain a τ-type phthalocyanine having a certain crystal form, and when this is used as a carrier generating material, the properties of an electrophotographic photoreceptor are insufficiently stable. Therefore, this τ-type metal-free phthalocyanine is compared to the X-type metal-free phthalocyanine,
It is poor in ease of manufacture, crystal stability, and potential stability for repeated use when used as a carrier generating material for electrophotographic photoreceptors.

By the way, known photoreceptors using organic photoconductive substances are generally used for negative charging.

The reason for this is that in the case of using negative charging, the mobility of holes among carriers is high, so it is possible to use materials with hole transport properties, which is advantageous in terms of photosensitivity, etc., whereas materials with electron transport properties can be used. There are almost no materials with excellent properties (,
Or, it cannot be used because it is carcinogenic.

However, it has been found that using such negative charging causes the following problems. In other words, during negative corona discharge or negative charging by a charger, a large amount of ozone is generated in the atmosphere, causing deterioration of the environmental conditions. This causes deterioration of the material on the surface of the photoreceptor, which causes a drop in potential during repeated use, which causes a decline in image quality and affects the lifespan of the photoreceptor itself.In addition, the discharge wire of the corona discharger is easily soiled. For these reasons, discharge unevenness and image unevenness may occur.

(Z) A toner of positive polarity is required for development of a negatively charged photoreceptor, but toner of positive polarity is difficult to manufacture in view of the triboelectrification series with respect to ferromagnetic carrier particles.

Therefore, it has been proposed to use a positively charged photoreceptor using an organic photoconductive substance. For example, a photoreceptor in which a carrier transport layer is laminated on a carrier generation layer and the carrier transport layer is made of a material having a high electron transport ability can be used for positive charging. However, as described above, there are almost no electron-transporting materials that have excellent properties, or they cannot be used due to environmental considerations, so the positive charging photoreceptor described above is not practical. For example, in order to provide the carrier transport layer with electron transport ability, trinitrofluorenone has been included, but this substance is inappropriate because it has carcinogenic properties.

On the other hand, a positive band, heavy-duty photoreceptor may be considered, in which a carrier generation layer is laminated on a carrier transport layer with a large hole transport ability.
This is not a practical layer structure because a very thin carrier generation layer is present on the surface side, resulting in poor rigidity, durability, sensitivity stability during repeated use, etc.

In addition, as a photoreceptor for positive charging, U.S. Patent No. 361541
Specification No. 4 discloses a material containing a thiapyrylium salt (carrier generating substance) so as to form a eutectic complex with polycarbonate (binder resin). However, this known photoreceptor has the drawbacks of a large memory phenomenon and a tendency to generate ghosts. US Patent No. 33
No. 57989 also discloses a photoreceptor containing phthalocyanine, but the characteristics of phthalocyanine change depending on the crystal type, and it is necessary to strictly control the crystal type. It is not suitable for copying machines that use a light source in the visible light wavelength range because of the insufficient amount of light and the large memory phenomenon.

Due to the above-mentioned circumstances, conventionally, it has been difficult to use a photoreceptor using an organic photoconductive substance for positive charging, and for this reason, it has been used mostly for negative charging.

C.9 Purpose of the Invention The purpose of the present invention is to provide a device that has sufficient sensitivity to relatively long wavelength light such as semiconductor laser light and can operate with positive charging;
In particular, it is an object of the present invention to provide a photoreceptor that generates less ozone, can maintain favorable environmental conditions, and has excellent rigidity resistance, potential stability, memory characteristics, and residual potential characteristics.

20 Structure of the Invention and Its Effects The present invention provides a photoreceptor having a layer containing a carrier generating substance and a binder substance, in which the main peak of the Black angle 2θ with respect to CuKα characteristic X-rays (wavelength 1.541) is at least 7. .5 degrees ±0.2 degrees, 9.1 degrees ±0.2
The layer contains metal-free phthalocyanine at 16.7 degrees ± 0.2 degrees, 17.3 degrees ± 0.2 degrees, and 22.3 degrees ± 0.2 degrees; The present invention relates to a photoreceptor characterized by containing a compound represented by formula [1].

General formula [I]: [However, in this general formula, R1 and RZ: each a hydrogen atom or a halogen atom, R3 and R4: each a substituted or unsubstituted aryl group, Ar': a substituted or unsubstituted arylene group represents. ] The photoreceptor of the present invention has a multilayer structure in which a carrier generation layer is laminated on a carrier transport layer, and a single layer structure in which a single layer contains both a carrier generation substance and a carrier transport substance. Including any of the following. That is, the above “
As described later, the carrier-generating substance (the metal-free phthalocyanine mentioned above) and the carrier-transporting substance (general formula (T
), and if the photosensitive layer has a laminated structure, the above "layer" corresponds to the carrier generation layer, and if the photosensitive layer has a single layer structure, the above "layer" corresponds to a single layer. This corresponds to the photosensitive layer.

Since the photosensitive layer of the photoreceptor of the present invention has the above-described structure, it is particularly suitable for use with positive charging.

Moreover, since the above-mentioned photoreceptor uses metal-free phthalocyanine having the main peak of Black's angle as a carrier-generating substance in the "layer", the potential stability during repeated use of the photoreceptor is improved. , there is little memory phenomenon, the residual potential is low and stable, and the crystals of the phthalocyanine itself are stable, making it easy to manufacture.

In addition, since this metal-free phthalocyanine exhibits high sensitivity in a long wavelength region, the photoreceptor of the present invention is suitable for semiconductor lasers and the like.

Further, according to the photoreceptor of the present invention, a "layer" containing a carrier-generating substance, a carrier-transporting substance, and a binder substance is used, and by providing this "layer" thicker, there are various advantages. .

That is, first, let's talk about the case where the photosensitive layer has a single layer structure.
The production of the photoreceptor is relatively easy, and it is only necessary to provide a single layer on a conductive substrate, etc., and the thickness of the photosensitive layer is 10 to 50 μm (preferably 15 to 30 μm).
By setting the thickness to m), good printing durability, durability, and sensitivity stability during repeated use can be obtained.

Regarding the case where the photosensitive layer has a laminated structure, the above-mentioned "layer", that is, the carrier generation layer is provided on the upper layer, so that it has a configuration for positive charging. The stiffness resistance, which is the problem mentioned above, can be fully satisfied. For example, the thickness is 0.6 to 10 μm (preferably 1 to 8 μm), which is much thicker than the normally considered thickness (about 0.2 μm for negatively charged use).
By providing a carrier generation layer with a thickness of , it is possible to obtain good rigidity resistance, durability, and sensitivity stability during repeated use.

In addition, in the photoreceptor of the present invention, if the content of the binder substance in the "layer" is increased, the film strength on the surface of the photoreceptor is improved in both the single-layer structure and the laminated structure, and it is possible to improve the film strength in the cleaning process etc. It is possible to prevent the surface of the photoreceptor from being scraped, and it is possible to improve wear resistance, rigidity resistance, and sensitivity stability during repeated use.

However, in a photoreceptor using the above-mentioned "layer", if the "layer" is provided thickly, and only the carrier-generating substance is included, as the "layer" becomes thicker, the "layer" becomes thicker. The concentration of the carrier-generating substance therein is relatively reduced, and the transport distance of positive and negative carriers from the carrier-generating position becomes large, resulting in a significant reduction in carrier transport ability. Additionally, increasing the amount of binder material in the "layer" reduces the concentration of carrier-generating material;
Carrier transport capacity decreases. This results in a decrease in sensitivity of the photosensitive layer, an increase in residual potential, an increase in memory phenomenon, a decrease in sensitivity during repeated use, and a decrease in charging potential.

In contrast, in the photoreceptor of the present invention, a specific carrier transport substance is added to the "layer", so that the above-mentioned problem can be technically solved. Here, the specific carrier transport substance is a compound represented by the above-mentioned general formula [I] (hydracine compound).

The reason why a specific carrier transporting substance was selected in this way is presumed to be that there is selectivity in carrier injection from the metal-free phthalocyanine, which is a carrier generating substance, to the carrier transporting substance in the same layer inside the “layer”. This is because it will be done.

On the other hand, if the combination of the charge-generating substance and the charge-transporting substance is inappropriate, it will cause a decrease in sensitivity, an increase in residual potential, and a decrease in potential stability during repeated use. Moreover, it is thought that there is no general rule for selecting the above-mentioned combinations, and the reality is that advantageous combinations are determined practically from among a large number of substance groups.

Here, the present inventors have discovered that by selecting the above-mentioned hydrazone compound, it becomes possible to technically solve the above-mentioned problems, and a photoreceptor having good characteristics can be obtained.

In other words, if the carrier transport material of the present invention is selected, the above-mentioned carrier injection will be performed efficiently, probably because the ionization potential is compatible with the metal-free phthalocyanine of the present invention, and the thickness of the "layer" will be reduced. Even if the value is increased and the concentration of the binder substance is increased, the transport ability of the carriers generated within the "layer" does not decrease, but rather improves, and therefore always has good sensitivity characteristics, residual potential characteristics, memory characteristics, and repeatability characteristics. Sensitivity characteristics and charging potential characteristics during use can be enjoyed.

Further, the carrier transporting substance of the present invention has excellent hole transporting ability, and by including it in the "layer", a photoreceptor suitable for use with positive charging can be obtained.

In addition, the hydrazone compound represented by the general formula [I] according to the present invention has excellent compatibility with various polymeric binders, and does not cause turbidity or opacity even if the amount of the hydrazone compound with respect to the polymeric binder is increased. Therefore, the range of mixing of the polymer binder can be very wide, making it possible to produce a photoreceptor with favorable charge transport performance and physical properties.

Due to the excellent compatibility, the charge transport phase is uniform and stable, and as a result, it has no sensitivity, charging characteristics, or fog, and can be used on a photoreceptor that can form a clear image with high sensitivity. Also, especially when used in repetitive transfer type electrophotography,
It is possible to achieve the effect that fatigue deterioration does not occur.

Additionally, the charge transport materials of the present invention are safe, environmentally friendly, and chemically stable.

In the above-mentioned "layer" constituting the photoreceptor of the present invention, a particulate carrier-generating substance and a carrier-transporting substance are bound together by a binder substance (that is, they are dispersed in the form of a pigment). good. In this case, the "layer" will have good rigidity, durability, etc., will have less memory phenomenon, and will have a stable residual potential.

Further, when using a positive charge, unlike when using a negative charge, the amount of ozone generated can be kept low, but a small amount of ozone generation is still unavoidable. However, the charge transport material of the present invention suffers from deterioration due to ozone adsorption.
< Therefore, image blurring and image defects are less likely to occur.

As described above, the present invention makes it possible to provide a photoreceptor suitable for use with positive charging. This makes it possible to exhibit the unique characteristics of using positive charging and solving the problems associated with using negative charging described in the section of the prior art. In other words, it is possible to keep ozone generating stars low and maintain favorable environmental conditions, avoid various problems such as uneven discharge due to dirt on the discharge electrode, and use negative polarity toner, which is easy to manufacture. can. Furthermore, since it is a functionally separated type, it has high sensitivity and high durability, and the selection of constituent materials is easy.

In the present invention, the metal-free phthalocyanine described above has an X-ray diffraction spectrum as shown in FIG.
That is, as shown in the figure, this metal-free phthalocyanine has C
Black angle (
However, the error is 2θ ± 0.2 degrees) is 7.5.9.1.16
．． It has a peak at 7.17.3.22.3, and a characteristic peak not found in the τ type at a Black angle of 22.3 degrees.
In addition, its infrared absorption spectrum has three peaks between 746 cm-' and 700 to 750 cm-', \1318 cm-' and 1330 cm-', as shown in Figure 2.
have peaks of equal intensity.

Furthermore, in the present invention, as shown in FIG. 3, Cu Kα(
The Black angle 2θ (however, the error is 2θ ± 0.2 degrees) for X-rays of 1,541 people is 7.7.9.3.16.
9.17.5.22.4.Has an X-ray diffraction spectrum with a main peak at 28.8 degrees, and has a Black angle of 16.9 with respect to the peak at the Black angle of 9.3 degrees in this X-ray diffraction spectrum The intensity ratio of the peak of the degree is 0.8 to 1
．． It is possible to use a metal-free phthalocyanine in which the intensity ratio of the peaks at the black angle of 22.4 degrees and 28.8 degrees to the peak at the black angle of 9.3 degrees is 0.4 or more. This phthalocyanine has a characteristic peak at a black angle of 28.8 degrees compared to that in FIG. This phthalocyanine is a tertiary
As is clear from the figure, for the type metal-free phthalocyanine shown in FIG.
The intensity ratio of the peak at 6.9 degrees is 0.9 to 1.0, but the latter intensity ratio cannot be determined because it does not have one of the black angles; Regarding the metal-free phthalonanine shown in , the intensity ratio of the peak at a black angle of 16.7 degrees to the peak at a black angle of 9.1 degrees corresponding to the intensity ratio of the former is 0.4 to 0.
．． 6, but for the latter intensity ratio, there is no peak corresponding to the black angle of 28.8 degrees, so the intensity ratio cannot be determined.

Furthermore, the infrared absorption spectrum of the metal-free phthalocyanine shown in Fig. 3 is 700 to 760 cm-' as shown in Fig. 4.
The four absorption bands with the strongest 720 ± 2 cm-'
1320±2c "1.3288±3 cm" is desirable, and as mentioned above, τ-type metal-free phthalocyanine has a characteristic absorption of 75 to 700 to 760 cm.
2 ± 2 cm-' has the strongest four absorption bands, 132
It is different from having two absorption bands instead of one from 0 to 1340 cm''.In addition, this metal-free phthalocyanine is
The infrared absorption spectrum of metal-free phthalocyanine shown in Figure 1 differs in the intensity ratio of the peaks at 700 to 760 cm-', and also has an absorption band at 1330 cm-', 3288±
They differ in that they have a characteristic absorption at 3 cm-'.

In addition, the visible and near-infrared absorption spectrum of the metal-free phthalocyanine in Figure 3 is 770 nm, as shown by the solid line in Figure 5.
It is desirable that the absorption maximum be at m or more and less than 790 nm, and the τ-type metal-free phthalocyanine shown by the broken line is 790 to 8
It has an absorption maximum at 20 nm, and many have an absorption maximum at about 810 nm.

In order to produce the metal-free phthalocyanine according to the present invention, the metal-free α-type phthalocyanine shown in FIG. The metal-free phthalocyanine shown in FIG. 3 is obtained by obtaining a phthalocyanine and then subjecting the metal-free phthalocyanine to a solvent treatment such as a dispersion treatment with a non-polar solvent such as tetrahydrofuran. For milling with stirring or kneading, dispersion media commonly used for dispersing, emulsifying, and mixing pigments, such as glass beads, steel beads, etc.
Alumina balls, flint stones, etc. are used. However, distributed media is not always required. A grinding aid may also be used, and as this grinding aid, those commonly used for pigments may be used, such as common salt,
Examples include bicarbonate of soda and sulfur salt. However, this grinding aid is also not necessarily required.

If a solvent is required during stirring, kneading, or grinding, it is preferable to use a solvent that is liquid at the temperature at which the stirring, kneading, or grinding is performed. Alternatively, it is preferable to select one or more solvents selected from the group of polyethylene glycol solvents, cellosolve solvents such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ketone solvents, and ester ketone solvents.

Typical devices used in the crystal transition process include general stirring devices, such as a homomixer, disperser, agitator, starter, kneader, bumper + J + mixer, ball mill, sand mill, and attritor. etc.

The superior properties of the metal-free phthalocyanine of the present invention produced as described above are such that the production method does not necessarily require a grinding aid and therefore does not require its removal, and temperature control is possible. The method for producing τ-type phthalocyanine does not need to be strict, and can be easily carried out at room temperature. is different.

In addition, the metal-free phthalocyanine of the present invention has an extremely stable crystalline form, and can be immersed in an organic solvent such as acetone, tetrahydrofuran, toluene, ethyl acetate, or 1,2-dichloroethane, or exposed for 50 hours or more in an atmosphere at 200°C. Even when subjected to heat resistance tests such as being left standing, or applying mechanical strain such as milling, transition to other crystal forms is difficult to occur, and this is of course superior to the conventional τ type (this point is The phthalocyanine shown in Figure 3 is particularly good). This makes it possible to manufacture the metal-free phthalocyanine of the present invention with less variation in its quality, and further facilitates its manufacture as well as the above, and also makes it easier to manufacture when used in electrophotographic photoreceptors. Characteristics such as potential stability and durability during repeated use can be improved.

The above-mentioned metal-free phthalocyanine used in the present invention has the following structural formula, and is mainly divided into those shown in FIG. 1 and those shown in FIG. 3 depending on its thermodynamic state.

Next, examples of compounds of the general formula N) include those having the following structural formula, but are not limited thereto.

In the present invention, one or more other carrier-generating substances may be used in combination with the metal-free phthalocyanine described above. Carrier generating substances that can be used in combination include, for example, α-type, β-type, τ-type, τ-type, τ′-type, η-type,
Examples include η′ type metal-free phthalocyanine. Also,
Other examples include phthalocyanine pigments, azo pigments, anthraquinone pigments, perylene pigments, polycyclic quinone pigments, methine squaric acid pigments, and the like.

Examples of azo pigments include the following.

(II-5) A-N=N-Ar2-CH=CH-Ar3-N=NA
(n-6) A-N=N-Ar2-CH=CH-Ar3-CH=CH
--Ar'-N=N-A (I[-8) A-N=N-Ar"-N=N Ar' N=N
A(II-9) A-N=N-Ar"-N=N-Ar"-N=N --A
r'-N=N-A -N=N-A [However, in each of the above general formulas, Ar", Ar' and Ar': each substituted or unsubstituted carbocyclic aromatic ring group, R5, R6 , R' and R8 are each an electron-withdrawing group or a hydrogen atom, and at least one of R5 to R8 is a cyano group Ar' (X is a hydroxy group, a substituted or unsubstituted alkyl group, RIK is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group), Y is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group, a sulfo group, a substituted or unsubstituted carbamoyl group. group or a substituted or unsubstituted sulfamoyl group (however, when m is 2 or more, mutually different groups may be used), Z is a substituted or unsubstituted carbocyclic aromatic ring, or a substituted or unsubstituted sulfamoyl group atomic group necessary to constitute the heterocyclic aromatic ring, R9 is a hydrogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamoyl group, a carboxyl group or an ester group thereof, Ar' is a substituted or an unsubstituted aryl group, n is ■
or an integer of 2, m is an integer of 0 to 4. )] Polycyclic quinone pigments of the following general formula (III) group can also be used in combination as carrier-generating substances.

General formula [■]: (However, in this general formula, X' is a halogen atom, a nitro group,
It represents a cyano group, an acyl group or a carboxyl group, p represents an integer of 0 to 4, and q represents an integer of 0 to 6. ) In the present invention, if a polymeric organic semiconductor having a condensed aromatic ring or a heterocyclic ring in the side chain is used together with the hydrazone compound (1) as the carrier transport substance, this polymeric organic semiconductor can be It has the property of generating photocarriers and effectively contributes to photosensitization.
As a result, the tail of the discharge curve is well cut, and the sensitivity is improved, especially in the low electric field region.As a result, in the conductive or insulating component development process, the capacitor can be removed without applying a bias voltage during the development stage. - When a bias voltage is applied during the component development process, the sharpness of the edge of the image decreases due to the so-called fringing phenomenon, causing blurring, but the above-mentioned polymeric organic semiconductor eliminates such problems. will decrease. Also,
The polymer organic semiconductor has a high absorbance in the ultraviolet light region and absorbs most of the ultraviolet light, and has a kind of filter effect on the ultraviolet light, so it has the effect of preventing the deterioration of the hydrazone compound, and the photosensitive layer UV light stability and durability can be improved.

Examples of the above-mentioned polymeric organic semiconductors include the following examples, but the present invention is not limited thereto.

(IV-1) (IV-2) (IV-3) (TV-4) (TV-5) 1+CH-CH output (IV-6) Lost CHGHZ W (IV-7) 10CH-CHha1 (rV-8> 1+CH-CH#- Hz (TV-9) -(-CH-CH CH.

CH.

! (IV-10) 6CHCHZ’JT Pi (rV-11) (TV-12) +CH-〇　H26 (IV-13) 1←CH-CH#- C=O amount (IV-14) (IV-15) tH5 (IV-16) (IV-17) -fO-CH-CH horoscope CH.

(TV-18) (IV-20) 1←CH-CH,t- (2) Among the above-mentioned polymeric organic semiconductors, poly-N-vinylcarbazole or its derivatives are highly effective and are preferably used. Such poly-N-vinylcarbazole derivatives are those in which all or part of the carbazole ring in the repeating unit is substituted with various substituents, such as an alkyl group, a nitro group, an amino group, a hydroxy group, or a halogen atom. .

Further, in a photoreceptor having a laminated structure, the carrier transport substance used in the carrier transport layer may be the above-mentioned hydrazone compound, but unlike the case of the carrier generation layer, it does not necessarily have to be a main component. That is,
Hydrazone compounds other than the above, carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidacilone derivatives, imidapridine derivatives, bisimidapridine derivatives, styryl compounds, birapurine derivatives, oxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives,
Phenazine derivatives, aminostilbene derivatives, poly-N
It may be one or more selected from -vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, triarylamine derivatives, phenylenediamine derivatives, stilbene 8%21, and the like.

The structure of a photoreceptor, such as an electrophotographic photoreceptor, based on the present invention can take various forms.

General configurations are illustrated in FIGS. 6 to 9.

The photoreceptor shown in FIG. 6 has a laminated structure, and a carrier transport layer 3 in which a carrier transport material is dispersed in a binder material is provided on a conductive support 1. In order to form a carrier generation layer 2 containing the above-mentioned metal-free phthalocyanine and the above-mentioned hydrazone compound as main components in a binder material, the above-mentioned metal-free phthalocyanine and the above-mentioned hydrazone compound are used.
A layer 6 containing the above-mentioned hydrazone compound as a main component in a binder material is formed to form a single-layer type photosensitive layer 4.

The photoreceptors shown in FIGS. 7 and 9 have the layer configurations shown in FIGS. 6 and 8, respectively, with an intermediate N5 provided between the photosensitive material N4 and the conductive support 1, so that the free electrons of the conductive support 1 are This effectively prevents the injection of

In FIGS. 6 to 9, a protective layer (film) may be further formed on the surface to improve printing durability, for example, a synthetic resin film may be coated.

The carrier generation layer 2 or layer 6 when forming the photosensitive layer having the above structure can be provided by the following method.

(a) A method of applying a solution in which a carrier-generating substance is dissolved in a suitable solvent, or a solution in which a binder is added and mixed and dissolved.

(b) A method in which a carrier-generating substance is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc. 6, and a binder is added as needed to mix and disperse the obtained dispersion, and the resulting dispersion is applied.

Dispersing the particles under the action of ultrasound in these methods allows for homogeneous dispersion.

Examples of the solvent or dispersion medium used for forming the photosensitive layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine,
Triethylenediamine, N.

N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, etc. be able to.

When a binder is used to form the photosensitive layer, any binder can be used, but a high molecular weight polymer that is hydrophobic, has a high dielectric constant, and has the ability to form an electrically insulating film is particularly preferred. Examples of such polymers include, but are not limited to, the following:

a) Polycarbonate b) Polyester C) Methacrylic resin d) Acrylic resin e) Polyvinyl chloride f) Polyvinylidene chloride g) Polystyrene h) Polyvinyl acetate i) Styrene-butadiene copolymer j) Vinylidene chloride-acrylonitrile copolymer k) Vinyl chloride-vinyl acetate copolymer l) Vinyl chloride-vinyl acetate-maleic anhydride copolymer m) Silicone resin n) Silicone-alkyd resin 0) Phenol-formaldehyde resin p) Styrene-
Alkyd resin q) Poly-N-vinylcarbazole r) Polyvinyl butyral These binders can be used alone or in a mixture of two or more.

"Layer" constituting the photoreceptor according to the present invention (in the sixth layer, the carrier-generating material is added to the binder material, and the carrier-generating material/binder material = 5 to 150% (i.e., 5% to 150% by weight per 100 parts by weight of the binder material). If the content is within a specific range (from 150 parts by weight, preferably from 10 to 100 parts by weight), it is possible to provide a positively charging photoreceptor with less reduction in residual potential and acceptance potential.

Outside the above range, if the amount of the carrier-generating substance is small, the photosensitivity will be poor and the residual potential will increase, and if it is too large, the acceptance potential will drop a lot and the memory will tend to increase.

In addition, the content of the carrier transport substance in the above “layer” is also important, and the carrier transport substance/binder substance = 20 to 2
00% (i.e. 20 parts by weight for 100 parts by weight of binder material)
~200 parts by weight, preferably 50 to 120 parts by weight); within this range, the residual potential is low and the photosensitivity is good, and the solvent solubility of the carrier transport substance is also maintained well. Outside this range, if the amount of carrier transport substance is small, the residual potential and photosensitivity tend to deteriorate, resulting in image defects, white spots, blurring, etc.; This content range of the carrier transport substance may be the same in the carrier transport layer 3 shown in FIGS. 6 and 7.

In addition, the ratio of the carrier-generating substance and the carrier-transporting substance in the “layer” is such that the weight ratio of the carrier-generating substance to the carrier-transporting substance is (1:0) so that the respective functions of both substances can be effectively exhibited. .2) to (1:10) is desirable, and (1:0.5) to (1:7) is even better. If the proportion of the carrier-generating substance is smaller than this range, the photosensitivity will be insufficient, and if the proportion is large, the carrier transport ability will decrease, resulting in insufficient sensitivity.

When the above “layer” is a carrier generation layer, the thickness of the carrier generation layer 2 is preferably 0.6 to 10 μm,
More preferably, the thickness is 1 to 8 μm.

If this thickness is less than 0.6 μm, the surface of the carrier generation layer will be mechanically damaged during repeated use due to usage conditions such as development and cleaning, resulting in part of the layer being scraped off and black streaks appearing on the image. It may appear as. Further, if the thickness is less than 0.6 μm, the sensitivity tends to be insufficient. However, if the thickness of the carrier generation layer exceeds 10 μm, the number of thermally excited carriers will increase, and as the environmental temperature increases, the acceptance potential will decrease, memory phenomenon will increase, and the density on the image will decrease. easy. Furthermore, when light having a wavelength longer than the absorption edge of the carrier-generating substance is irradiated, photocarriers are generated even near the bottom of the charge-generating layer. In this case, electrons must move through the layer to the surface, and generally sufficient transport ability tends to be difficult to obtain. Therefore, during repeated use, the residual potential tends to increase (
Become.

Further, when the above-mentioned "layer" is a photosensitive layer with a single layer structure, the thickness of the photosensitive layer is preferably 10 to 50 μm, and 15 μm.
It is more preferable if it is 30 μm. This film thickness is 15μ
If the thickness is less than m, the charging potential will be low due to the thinness, and the rigidity resistance will also be poor. Furthermore, if the thickness of the photosensitive layer 6 exceeds 50 μm, the residual potential will increase, and the same phenomenon as described above when the carrier generation layer is too thick will occur.
There is a tendency for it to become difficult to obtain sufficient transport capacity, and therefore the residual potential tends to increase during repeated use.

Further, the thickness of the carrier transport layer 3 in FIGS. 6 and 7 is 5 to 5.
The thickness is preferably 50 μm, preferably 5 to 30 μm.
If the thickness is less than 5 μm, the charged potential will be small because it is thin, and if it exceeds 50 μm, the residual potential will tend to increase.

In addition, the film thickness ratio of the carrier generation layer and the carrier transport layer is 1:
(1 to 30) is desirable.

When the photosensitive layer is formed by dispersing the carrier-generating substance, the carrier-generating substance has a thickness of 5 μm or less,
It is preferable that the powder has an average particle diameter of 0.1 μm or more, preferably 2 μm or less, and 0.2 μm or more. In other words, if the particle size is too large, dispersion in the layer will be poor, and the particles will protrude from the surface, resulting in poor surface smoothness, and in some cases, electrical discharge may occur at the protruding portions of the particles.
Alternatively, toner particles tend to adhere there, causing a toner filming phenomenon. For carrier-generating substances that are sensitive to long-wavelength light (~700 nm), the surface electron density is neutralized by the generation of thermally excited carriers in the carrier-generating substance, and if the particle size of the carrier-generating substance is large, This neutralizing effect is thought to be significant.

Therefore, high resistance and high sensitivity can only be achieved by reducing the particle size. However, if the particle size is too small, it tends to aggregate, which increases the abrasion resistance of the layer, increases crystal defects, reduces sensitivity and repeatability, and reduces charging ability. Further, since there is a limit to miniaturization, it is desirable that the lower limit of the average particle size is 0.01 μm.

Furthermore, the photosensitive layer has improved sensitivity and a residual potential. Examples of electron-accepting substances that can be used here include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, tetrachlorophthalic anhydride,
Tetrabromo phthalic anhydride, 3-nitro phthalic anhydride,
4-nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1,3.5-trinitrobenzene, varanitrobenzonitrile, Picryl chloride, quinone chlorimide,
Chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 9
-Fluorenylidene [dicyanomethylenemalonodinitrile], polynitro-9-fluorenylidene [dicyanomethylenemalonodinitrile], picric acid, O-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, penta Examples include fluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellinate acid, and other compounds with high electron affinity. Also, electron (is, 100 :Q, l ~ 100
It is.

The support 1 on which the photosensitive layer is to be provided is a metal plate, a metal drum, or a conductive thin layer made of a conductive polymer, a conductive compound such as indium oxide, or a metal such as aluminum, palladium, or gold, by coating, vapor deposition, or evaporation. Those provided on a substrate such as paper or plastic film by means such as lamination are used. The intermediate layer that functions as an adhesive layer or barrier layer is made of a polymer such as the binder resin described above, an organic polymer material such as polyvinyl alcohol, ethyl cellulose, or carboxymethyl cellulose, or aluminum oxide. is used.

A major feature of the photoreceptor of the present invention is that the maximum value of the photosensitive wavelength range of the metal-free phthalocyanine used in the present invention is 770.
If it exists in the range of 790 nm or more and less than 790 nm, this metal-free phthalocyanine is optimal as a photoreceptor for semiconductor lasers, and as mentioned above, the crystal form of this metal-free phthalocyanine is extremely stable.
Transition to other crystal forms is unlikely. This is a great advantage not only in the production and properties of the metal-free phthalocyanine used in the present invention, but also in the production and use of electrophotographic photoreceptors.

Another major feature of the present invention is that the layer containing the metal-free phthalocyanine contains a hydrazone compound (
I), which makes it possible to provide a photoreceptor particularly suitable for use with positive charging.

E. Examples Hereinafter, the present invention will be explained in detail with reference to specific examples and comparative examples.

First, a synthesis example of a metal-free phthalocyanine compound A having the properties shown in Figs. 1 to 2, a synthesis example of a metal-free phthalocyanine compound B having the properties shown in Figs. 3 to 5, and a synthesis example of a τ-type metal-free phthalocyanine compound. shows.

<Synthesis Example 1> 50 g of lithium phthalocyanine was added to 600 n+1 concentrated sulfuric acid that had been sufficiently stirred at 0°C. The mixture was then stirred at this temperature for 2 hours.

The resulting solution was then filtered through a coarse sintered glass funnel and poured slowly into 4 liters of ice and water with stirring. After standing for several hours, the mixture was filtered and the resulting mass was washed with water until neutral. The mass was then finally washed several times with methanol and dried in air. The dried powder was extracted with acetone in a 24 hour continuous extractor and dried in air to give a blue powder.

In the above, the precipitation was repeated to ensure a salt residue for lithium. 30.5 g of blue powder was thus obtained. The X-ray diffraction pattern of the obtained product was consistent with the X-ray diffraction pattern of an α-type phthalocyanine compound described in previously published materials.

30 g of the metal-free α-phthalocyanine compound thus obtained was charged into a porcelain ball mill with an inner volume of 900 m and 12 half grooved with 13/16-inch diameter balls, and milled at about 8 Orpm for 164 hours. A metal-free phthalocyanine compound A was obtained. This compound exhibited the X-ray diffraction spectrum shown in FIG.

<Synthesis Example 2> Metal-free phthalocyanine compound A of Synthesis Example 1 and an organic solvent such as tetrahydrofuran or 1,2-dichloroethane 200
m 7! was added to the ball mill and milled again for 24 hours. The organic solvent was removed from the dispersion after milling and the dispersion was dried to obtain 828.2 g of a metal-free phthalocyanine compound. This compound exhibited the X-ray diffraction spectrum shown in FIG.

<Synthesis Example 3> An α-type metal-free phthalocyanine compound (Monolite Fast Pull GS manufactured by ICI) was extracted and purified three times with heated dimethyl formaldehyde. Through this operation, the purified product was transferred to the β form.

Next, a portion of this β-type metal-free phthalocyanine compound was dissolved in concentrated sulfuric acid, and this solution was poured into ice water to cause reprecipitation, thereby transforming it into the α-type.

After washing this reprecipitate with aqueous ammonia, methanol, etc.
It was dried at 0°C. Next, the α-type metal-free phthalocyanine compound purified above was placed in a sand mill together with a grinding aid and a dispersant, and kneaded at a temperature of 100±20° C. for 15 to 25 hours. After confirming that the crystal form has changed to the τ type by this operation, take it out from the container, thoroughly remove the grinding aid and dispersant with water and methanol, etc., and dry it to form a clear bluish τ. Blue crystals of type-free metal phthalocyanine were obtained.

This phthalocyanine showed the X-ray diffraction spectrum shown in FIG.

1. Examples 1 to 9, Comparative Example 1.2 Vinyl chloride-vinyl acetate-
An intermediate layer having a thickness of 0.05 μm made of a maleic anhydride copolymer “Esresoku MF-10” (manufactured by Block Chemical Co., Ltd.) was formed. Next, the carrier transport substance and binder resin (polycarbonate: Panlite L-1) shown in FIG.
250) and 1,2-dichloroethane 57nj! Dissolved in? 8 liquid was applied onto the intermediate layer to form a carrier transport layer. Next, the average particle size shown in Figure 10 is 1 μm.
A dispersion obtained by adding each carrier generating substance, each carrier transporting substance, and a binder resin to 67 ml of 1,2-dichloroethane and dispersing them in a ball mill for 12 hours is applied onto the carrier transporting layer and dried to form a carrier generating layer. Then, each electrophotographic photoreceptor was manufactured.

The electrophotographic photoreceptor thus obtained was tested using an electrostatic tester rE.
The charger was installed in a P A-810 (L type) (newly manufactured by Kawaguchi Electric) and the following characteristic tests were conducted.
After applying a voltage of 6 KV and charging the photosensitive layer by corona discharge for 5 seconds, the photosensitive layer was left in a device for 5 seconds, and then the surface of the photosensitive layer was irradiated with 780 nm light separated by a spectrometer.
The exposure amount required to attenuate the surface potential of the photosensitive layer by 1/24, that is, the half-reduction exposure slip E1/2 was determined. Also,
Acceptance potential when charged by the above corona discharge ■1 and 10ρ
The initial value of residual potential (8) after ux' sec exposure and the value after 10,000 copies were measured.

Further, a photoreceptor layer similar to that shown in the example was formed on an A1 drum, and a laser beam printer LP-
It was installed in a modified machine (using a semiconductor laser light source) 3010 (manufactured by Konishiroku Photo Industry 0'@) and image evaluation was performed (CD is image density and R is resolution).

◎::A degree is sufficiently high and resolution is also very good.

(CD≧1.2, R≧6.0) ○: Both density and resolution are good.

(1,2>CD≧0,7.6.0>R≧4.0) ×: The density is low (and the resolution is not sufficient. Also, fogging and white or black spots appear.

In addition, CD is Sakura Densitometer (Model PDA
-65: Konishiroku Photo Industry Co., Ltd.), and R was measured using a Sakura densitometer (Model PDM-5: Konishiroku Photo Industry Co., Ltd.). For both CD and R, the density of the blank paper is 0.0.
The evaluation was conducted by measuring the reflection density.

However, the specific measuring method for R was as follows. That is, a resolution chart is measured using a microdensitometer with a slit of 500μ×20μ. The determination criteria for the resolving power chart is based on the resolving power chart in which the following equation has a response of 30% or more. The density of the image area of the copy image is D ``m':%'Y, the density of the non-image area is D GIY, and the density of the image area of the original document is D 4ga.
g'9, and when the density of the non-image area is Du・da, D; py 1) c% py According to this result, based on the present invention, all of the samples of Examples 1 to 9 are It can be seen that the electrophotographic properties are considerably better than those of Sample No. 1.2. In particular, the use of the metal-free phthalocyanine of the present invention as a CGM and the addition of a hydradun compound (CI) as a CTM to the carrier generation layer both greatly influence the characteristics of the photoreceptor.
It is possible to obtain remarkable results as a positive charging photoreceptor, such as a high charging potential and good stability, and a large improvement in photosensitivity. Tests using semiconductor lasers also revealed that high density and high resolution were obtained, and long wavelength sensitivity was improved.

Kasei Masukenji U- Each electrophotographic photoreceptor was produced in the same manner as in Examples 1 to 9, except that the carrier generating substance used was changed to metal-free phthalocyanine compound B, and the same tests were conducted. However, the results shown in FIG. 11 were obtained.

From this result, all the samples of Examples 10 to 12 based on the present invention show good results.

Examples 13 to 18, Comparative Example 3.4 Vinyl chloride-vinyl acetate-
Maleic anhydride copolymer “Eslenoku MF-10J”
(manufactured by Block Chemical Co., Ltd.) with a thickness of 0.05 μm was formed.

Next, each carrier generating substance and each carrier transporting substance having an average particle size of 1 μm shown in FIG. 12 and a binder resin polycarbonate (Panlite L-1250) were mixed in a 1.2-
A dispersion obtained by adding 61 ml of dichloroethane and dispersing in a ball mill for 12 hours was applied onto the intermediate layer and dried to form a photosensitive layer, thereby producing each electrophotographic photoreceptor.

When these electrophotographic photoreceptors were subjected to the same test as described above, the results shown in FIG. 12 were based on the present invention (the samples of Examples 13 to 18 showed good results, but Comparative example 3 without using A.
All of No. 4 had insufficient characteristics.

Example 19.20 Electrophotographic photoreceptors were prepared in the same manner as in Examples 13 to 18, except that the carrier generating substance used was changed to metal-free phthalocyanine compound B, and the same tests were conducted. The results shown in FIG. 13 were obtained.

From this result, all the samples of Examples 19 and 20 based on the present invention show good results.

[Brief explanation of the drawing]

Figures 1 to ## illustrate the present invention, and Figures 1 and 3 illustrate each X on the two sides of the metal-free phthalocyanine.
Line diffraction spectrum, Figures 2 and 4 are infrared absorption spectra of the two sides of metal-free phthalocyanine, Figure 5 is near-infrared spectrum of metal-free phthalocyanine, Figures 6 and 7 are layers, respectively. FIGS. 8 and 9 are partial cross-sectional views of a single-layer structure photoreceptor, and FIGS. 10, 11, 12, and 13 are each electrophotographic photoreceptor. FIG. 3 is a diagram showing a comparison of changes in body characteristics. FIG. 14 is an X-ray diffraction spectrum diagram of a conventional τ-type metal-free phthalocyanine. In addition, in the reference numerals shown in the drawings, 1-.--Conductive support 2--Carrier generation layer 3--Carrier transport layer 4--1 Photosensitive layer 5 - Intermediate layer 6 - One layer. Agent: Hiroshi Aisaka, Patent Attorney Figure 1 Figure 3
, ) ) (Voluntary) Procedures: June 1988, Patent Application No. 315164) No. 2, Name of the invention Photoreceptor 3, Relationship with the person making the amendment Patent applicant address Tokyo 1-26-2 Nishi-Shinjuku, Shinjuku-ku Name
(127) Konishiroku Photo Industry Co., Ltd. 4, Agent

Claims (1)

[Scope of Claims] 1. In a photoreceptor having a layer containing a carrier generating substance and a binder substance, CuKα characteristic X-rays (wavelength 1.
541 Å) at least 7.5 degrees ± 0.2 degrees, 9.1 degrees ± 0.2 degrees, 16
．． 7 degrees ± 0.2 degrees, 17.3 degrees ± 0.2 degrees and 22.3 degrees
A photoreceptor characterized in that the layer contains metal-free phthalocyanine at a temperature of ±0.2 degrees, and further contains a compound represented by the following general formula [I]. General formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, in this general formula, R^1 and R^2: respectively, hydrogen atoms or halogen atoms, R^3 and R^4: respectively, Substituted or unsubstituted aryl group, Ar^1: represents a substituted or unsubstituted arylene group. ]