JPH0416850A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and durability by incorporating an X-type metal-free phthalocyanine as an electric charge generating material and a specified compound as a charge transfer material and a polycarbonate resin as a binder resin. CONSTITUTION:The X-type metal-free phthalocyanine is used as the charge generating material, and the 1,1,4,4-tetraphenyl-1,3-butadiene compound represented by formula I is used as the charge transfer material, and the polycarbonate resin having repeating units each represented by formula II is used as the binder resin. In formulae I and II, R1 is lower dialkylamino group; R2 is H or same as R1; and each of R3 - R10 is independently H, halogen, or alkyl, thus permitting sensitivity and durability to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly, to an electrophotographic photoreceptor containing a specific charge-generating material, a specific charge-transporting material, and a specific binder resin. This invention relates to an electrophotographic photoreceptor with high sensitivity and high durability.

[Problems to be solved by conventional techniques and inventions] In recent years,
The development of copiers and printers using electrophotography has been remarkable, and there are various sRs depending on the purpose.

R1 L. Models with different shapes, types, and functions have been developed, and correspondingly, a wide variety of photoreceptors are being developed to be used for them.

Conventionally, inorganic compounds have been mainly used as electrophotographic photoreceptors due to their sensitivity and durability. Examples include zinc oxide, cadmium sulfide, and selenium. However, these often use harmful substances, and their disposal becomes a problem and causes pollution. Furthermore, when selenium, which has good sensitivity, is used, it is necessary to form a thin film on a conductive substrate by a vapor deposition method or the like, resulting in poor productivity and increased costs.

In recent years, amorphous silicon has attracted attention as a non-polluting inorganic photoreceptor, and its research and development is progressing. However, although these also have excellent sensitivity, since plasma CVD is mainly used when forming thin films,
Its productivity is extremely poor, and both the photoreceptor cost and running cost are large.

On the other hand, organic photoreceptors can be incinerated and have the advantage of being non-polluting, and many of them can be coated to form thin films, making mass production easy. Therefore, it has the advantage of being able to significantly reduce costs and being able to be processed into various shapes depending on the application. However, organic photoreceptors still have problems with their sensitivity and durability.
The emergence of organic photoreceptors with high sensitivity and high durability is strongly desired.

Various methods have been proposed to improve the sensitivity of organic photoreceptors, but currently the mainstream is a functionally separated photoreceptor with a two-layer structure in which the functions are separated into a charge generation layer and a charge transport layer. There is. For example, charges generated in the charge generation layer due to exposure to light are injected into the charge transport layer, transported through the charge transport layer to the surface, and by neutralizing the surface charges, an electrostatic latent image is formed on the surface of the photoreceptor. be done. Compared to the single-layer type, the function-separated type has a smaller possibility of trapping generated charges, and the charges can be efficiently transported to the photoreceptor surface without each layer having its own function inhibited (U.S. Patent No. 280
No. 3541).

As the organic charge generating material used in the charge generating layer, compounds that absorb the energy of irradiated light and efficiently generate charges are selectively used. ), metal-free phthalocyanine pigments (JP-A-60143346), metal phthalocyanine pigments (JP-A-50-16538), squareium salts (JP-A-53-27033), and the like.

As the charge transport material used in the charge transport layer, it is necessary to select a compound that has a high charge injection efficiency from the charge generation layer and also has a high charge mobility within the charge transport layer.

For this purpose, compounds with small ionization potential,
Compounds that easily generate cation radicals are selected, such as triarylamine derivatives, disclosed in Japanese Patent Application Laid-open No. 53-47260.
Publication No.), hydrazone derivatives (Japanese Patent Application Laid-Open No. 57-10184
4), oxadiazole derivatives (Japanese Patent Publication No. 3454)
66), pyrazoline derivatives (Japanese Patent Publication No. 524188)
No. 58198043), stilchen derivatives (Japanese Patent Application Laid-Open No. 58198043)
(Japanese Patent Publication No. 45-5), triphenylmethane derivatives (Japanese Patent Publication No. 45-5
No. 55), 1,3-butadiene derivatives (Japanese Unexamined Patent Publication No. 1983)
2-287257) etc. have been proposed.

However, the charge mobility of these materials is small compared to that of inorganic materials, and the sensitivity is still unsatisfactory, so there has been a need for further improved materials.

On the other hand, in order to improve durability, it is necessary to overcome photodegradation of charge-generating materials and charge-transporting materials, ozone oxidation, redox deterioration, and mechanical abrasion caused by toner, paper, cleaning blades, etc. on the outermost layer. . In particular, ozone oxidation and mechanical wear of the charge-generating material or charge-transporting material used in the outermost layer are issues that need to be solved immediately, and various studies have been carried out, but none have been found to be satisfactory. The current situation is that this is not the case. For example, it has been proposed to provide a protective layer on the outermost layer in order to solve the above problems. By doing so, the above-mentioned ozone oxidation and mechanical wear can be solved; however, it causes a decrease in sensitivity, an increase in residual potential, etc., which adversely affects the image.

As described above, there has been no one that satisfies all of sensitivity, durability, and high image quality, and it is strongly desired to realize these characteristics.

[Means to solve the problem]

As a result of intensive research to solve the above problems, the present inventors have developed a specific charge generation material with high charge generation efficiency, a specific charge transport material that exhibits high charge mobility and is stable against ozone oxidation, and a wear-resistant material. By using a specific binder resin with excellent sensitivity,
The inventors have discovered that an electrophotographic photoreceptor with excellent durability can be obtained, leading to the present invention.

That is, the present invention provides an electrophotographic photoreceptor comprising a conductive support, a charge generating material, and a charge transporting material as essential components,
The charge generating material is an X-type metal-free phthalocyanine, and the charge transporting material is represented by the general formula (1) (wherein, Ro represents a di-lower alkylamino group, and R2 represents a hydrogen atom or a di-lower alkylamino group). 1,1.4.4-tetraphenyl-1,3-
Contains a phtadiene compound and has the general formula (
2) (wherein, R3, R4+ R5+ R6+ R7, Rs,
R9 and R1° are the same or different and represent a hydrogen atom, a halogen atom, or an alkyl group. ) The present invention provides an electrophotographic photoreceptor characterized by containing a polycarbonate resin having a repeating unit represented by the following formula.

The charge generating material used in the present invention contains X-type metal-free phthalocyanine as an essential component. Various crystal types of metal-free phthalocyanine compounds are known, such as α-type, β-type, η-type, τ-type, η゛-type, τ'-type, and X-type, among which X-type metal-free phthalocyanine is known. is most preferred. This X-type metal-free phthalocyanine is easy to synthesize and has excellent stability, and its absorption wavelength range extends to the semiconductor laser range, providing electrophotographic photoreceptors with high sensitivity and high durability at each wavelength. Is possible. The X-type metal-free phthalocyanine used in the present invention is
It can be synthesized and prepared by known methods, and can also be converted from other crystal forms to X form by known methods such as mechanical treatment, thermal treatment, chemical treatment, etc.

In addition, 1, L represented by the general formula (1) used in the present invention
Specific examples of the 4,4-tetraphenyl-1,3-butadiene compound are shown below, but the present invention is not limited thereto.

These compounds exhibit high charge mobility and provide highly sensitive electrophotographic photoreceptors. It is also stable against ozone oxidation and has excellent chemical and electrical stability.

In the present invention, in order to further improve the abrasion resistance of the electrophotographic photoreceptor, a polycarbonate resin having the repeating unit shown in general 2 (2) above is used. This is generally referred to as polycarbonate Z resin.

Conventionally, polycarbonate resins made from bisphenol A have been widely used as binder resins for electrophotographic photoreceptors because they have excellent properties such as electrical insulation, mechanical properties, and transparency. However, although conventional polycarbonate resins made from bisphenol A have the above characteristics, they also have drawbacks such as low complete solubility in solvents and poor compatibility with charge transport materials. As a result, the following problems arise.

■ When preparing a photosensitive layer coating solution using polycarbonate resin made from bisphenol A, select a solvent that has good solubility in this resin and a charge transport material that is compatible with this resin. There is a need. Furthermore, when producing photoreceptors using these materials, depending on the type of good solvent used in the coating solution, the coated photosensitive layer may become white or charge transport may occur in the photosensitive layer. Crystals of the material may precipitate. This crystallized part does not respond to light, so the residual potential in that part becomes high.
Appears as an image defect. Furthermore, when we investigated the storage stability (pot life) of this photosensitive layer coating solution during long-term use, we found that the coating solution gelled within a few days, making it impossible to obtain a stable coating solution. .

■ When a photoconductor is manufactured using polycarbonate resin made from bisphenol A, its initial electrical properties and mechanical strength are good, but the environment in which the photoconductor is placed inside a copier or printer (corona discharge, toner, paper,
The surface of the photosensitive layer may change slightly due to friction with a cleaning blade, etc., environmental atmosphere such as temperature and humidity, etc.
The charge transporting material in the photosensitive layer precipitates as microcrystals on the surface of the photosensitive layer, reducing the sliding properties of the photosensitive member surface and causing mechanical damage to toner, paper, cleaning blades, etc. due to repeated use. The strength decreases, the surface of the coating film is easily damaged, and the film thickness decreases significantly, resulting in a decrease in the electrical properties of the photoreceptor and a decrease in image quality.

■ Coating films made using polycarbonate resin made from bisphenol A have a strong intermolecular attraction of the resin itself, so it is difficult to coat the base material (conductive support, charge generating material, undercoat layer, intermediate layer, blocking layer, etc.). ), and the crank easily enters the membrane.

Therefore, in order to solve the above problems, the present inventors introduced a cyclohexyl group into the main chain of polycarbonate resin as shown in General 2 (2). (1) By reducing the crystallinity of the resin. , improves solubility in solvents and compatibility with charge transport materials, prevents gelation of coating liquids and improves storage stability, ■ improves sliding properties of resins, and does not change the glass transition point ( Improved scratch resistance and mechanical strength of the coating film by increasing its toughness; ■ Adding flexibility to the resin to improve the base material (conductive support, charge-generating material, undercoat layer, intermediate layer, blocking layer) It has become possible to improve the adhesion with other layers (e.g., layers, etc.).

Specific examples of repeating units of the polycarbonate resin having repeating units represented by general formula (2) used in the present invention include the following, but the present invention is not limited thereto.

H3 H3 The number average molecular weight of these polycarbonate resins is preferably 5,000 to 100,000. If it is smaller than 5%, mechanical strength cannot be obtained and abrasion resistance cannot be expected. If it is larger than 100,000, the viscosity becomes too large during coating, resulting in difficulty in workability. Glass transition point is 50°C to 20°C
0°C, and wear resistance is improved within this range.

If the glass transition point is lower than 50°C, the environmental properties will deteriorate, which is not preferable. Further, if the temperature is higher than 200°C, brittleness occurs and wear and deterioration becomes severe.

X-type metal phthalocyanine as shown above, general 2 (
1,1,4,4-tetraphenyl 1.3 shown in 1)
- An electrophotographic photoreceptor is produced using a butadiene compound and a polycarbonate resin having a repeating unit represented by general 2 (2).

The electrophotographic photoreceptor has three configurations: a negatively charged function-separated type as shown in Figure 1, a negatively charged single layer type as shown in Figure 2, and a third type as shown in Figure 2.
Any of the positively charging function-separated types shown in the figure can be used.

To explain the negative charging function-separated type shown in FIG. 1, an undercoat layer 2 is provided on a conductive support 1 as necessary to improve adhesion and charging properties. A charge generation layer 3 that absorbs irradiated light and generates charges is provided thereon. Furthermore, a surface protective layer 5 may be provided as necessary on the 0th layer on which a charge transport layer 4 for transporting the generated charges to the surface is laminated. The manufacturing method will be explained in detail below.

As the base material of the conductive support, metals such as aluminum and nickel, metal-deposited polymer films, metal-laminated polymer films, etc. can be used, and the conductive support is formed in the form of a drum, sheet, or belt. form.

The charge generation layer is made of X-type metal-free phthalocyanine as a charge generation material and, if necessary, a binder and additives. Methods for forming both photostop layers include vapor deposition and plasma CVD.
There are methods such as coating method and coating method. If the raw material is metal phthalocyanine such as indium phthalocyanine, (1
) Since the pigments are tightly aggregated, it is very difficult to make them into fine particles, making it difficult to make uniform and stable paints.

(2) Pigments are extremely difficult to purify and contain impurities, so when a photoreceptor is manufactured, dark decay increases due to the influence of these impurities, reducing the electrical properties of the photoreceptor. cause it to happen.

There are other problems. Therefore, a vapor deposition method is often used to remove these impurities and obtain a highly pure charge generating material in the form of fine particles.

However, this vapor deposition method has the drawbacks of lower productivity and higher cost than the coating method.

In the present invention, productivity is improved by using X-type metal-free phthalocyanine, which is easy to refine and make into fine particles.
The photoreceptor can be manufactured using a coating method that is advantageous in terms of cost.

The thickness of the formed charge generation layer is preferably 0.1 to 2.0 -, more preferably 0.1 to 1.0 -.

Next, on the top of the charge generation layer, 1 represented by the general formula (1),
1.4.A charge transport layer containing a 4-tetraphenyl-1,3-butadiene compound as a charge transport material is formed into a thin film. A coating method is mainly used to form a thin film, in which a 1゜1.4.4-tetraphenyl-1,3-butadiene compound represented by general formula (1) is mixed with a binder of general formula (2). It may be dissolved in a solvent together with a polycarbonate resin having a repeating unit represented by the formula, coated on the charge generation layer, and then dried.

Furthermore, LL4 represented by the general formula (1) used in the present invention
．． Paints made by dissolving 4-tetraphenyl-1,3-butadiene compounds and polycarbonate resins having repeating units represented by general 2 (2) have excellent storage stability and have extremely few defects during coating. Become. Therefore, an electrophotographic image containing a 1,1,4,4-tetraphenyl-1,3-butadiene compound represented by general formula (1) and a polycarbonate resin having a repeating unit represented by general formula (2) in the same layer. Photoreceptors have the advantage of providing high image quality as well as sensitivity and durability.

The solvent used is not particularly limited as long as it dissolves the above compound and does not dissolve the charge generation layer.

In the present invention, a polycarbonate resin having a repeating unit represented by the general formula (2) is used as the binder resin, but it can also be used together with other insulating resins, such as other polycarbonates, polyarylates, polyesters, polyamides, etc. Condensation polymers such as polyethylene,
Addition polymers such as polystyrene, styrene-acrylic copolymer, polyacrylate, polymethacrylate, polyvinyl butyral, polyacrylonitrile, polyacrylamide, acrylonitrile-butadiene copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer; polysulfone , polyether sulfone, silicone resin, etc. may be used as appropriate, and one or more types may be used as a mixture.

The amount of the binder resin used is 1,1 as shown by the general formula (1).
．． The weight ratio is 0.1 to 3, preferably 0.1 to 2, relative to the 4,4-tetraphenyl-1,3-butadiene compound. If the amount of the binder resin is larger than this, the concentration of the charge transporting material in the charge transporting layer will be low, resulting in poor sensitivity.

In addition, when using a polycarbonate resin having a repeating unit represented by general formula (2) together with another insulating resin as a binder resin, the amount of polycarbonate resin having a repeating unit represented by general formula (2) to be used is The amount is 30 to 99 weight percent of the total amount of binder resin, and if it is less than that, the abrasion resistance will not be improved. Further, in the present invention, it is also possible to use a combination of known charge transport materials as described above, if necessary.

The coating means for the charge transport layer is not limited, and for example, a dip coater, bar coater, calendar coater, gravure coater, spin coater, etc. can be used as appropriate, and electrodeposition coating can also be used.

The thickness of the charge transport layer thus formed is preferably 10 to 50 μM, more preferably 10 to 30 μM.
It is. If the film thickness is greater than 50 mm, it will take more time to transport the charge, and the probability that the charge will be captured will also increase, causing a decrease in sensitivity. On the other hand, 10
If it is smaller than -, the mechanical strength will decrease and the life of the photoreceptor will be shortened, which is not preferable. As described above, the X-type metal-free phthalocyanine was used as the charge generating material, the 1,L4,4-tetraphenyl-1,3-butadiene compound represented by the general formula (1) was used as the charge transport material, and the general formula was used as the binder resin. An electrophotographic photoreceptor containing a polycarbonate resin having the repeating unit shown in (2) can be produced, but in the present invention, an undercoat layer may be further provided between the conductive support and the charge generation layer, if necessary. These layers can be made of insulating resins such as polyvinyl butyral, phenol resins, and polyamide resins, conductive inorganic fine powders dispersed in insulating resins, or conjugated polymers such as polypyrrole and polythiophene. Any conductive polymer whose molecules are doped with ions can be used. or,
A surface protective layer can also be provided on the surface of the photoreceptor, and in this case, an insulating resin is mainly used for this surface protective layer, but a polycarbonate resin having a repeating unit shown in general 2 (2) may be used as necessary. It may also be used together with other insulating resins, making it possible to improve wear resistance. As other insulating resins, the same ones as in the case of the charge transport layer can be used, and the ratios thereof are also the same.

When using the electrophotographic photoreceptor thus obtained, first the surface of the photoreceptor is negatively charged using a corona charger or the like. After being charged, charges are generated in the charge generation layer by exposure to light, and positive charges are injected into the charge transport layer, which are transported through the charge transport layer to the surface, neutralizing the negative charges on the surface. be done. On the other hand, negative charges will remain in the unexposed areas. In the case of regular development, a positive toner is used, and in the case of 0 reversal development, in which the toner adheres to the area where this negative charge remains and is developed, a negative toner is used.
Toner adheres to the areas where the charges have been neutralized and is developed. The electrophotographic photoreceptor of the present invention can be used in any developing method and can provide high image quality. Further, even after repeated use, there is almost no wear and tear, and high durability can be provided.

Further, in the present invention, as shown in FIG. 3, an undercoat layer 2 is provided on the conductive support 1 as necessary, a charge transport layer 4 is first provided on the undercoat layer 2, and a charge generation layer 3 is provided on the undercoat layer 4. It is also possible to provide a positive charging function-separated type electrophotographic photoreceptor by providing a surface protective layer 5 as required. In this case as well, 1, 1.4.
A polycarbonate resin having a 4-tetraphenyl-1,3-butadiene compound and a repeating unit represented by general 2 (2) may be used together with other binder resins as necessary. The same insulating resin as described above can be used as needed, and the ratio thereof is also the same as described above.

In addition, for the purpose of improving wear resistance, a charge generation layer and/or
Alternatively, a polycarbonate resin having a repeating unit represented by general formula (2) may be used for the surface protective layer.

When using such a photoreceptor, first the surface of the photoreceptor is positively charged, and after exposure, the generated negative charge neutralizes the surface charge of the photoreceptor, and the positive charge passes through the charge transport layer and becomes conductive. It will be transported to a support.

Further, in the present invention, as shown in FIG. 2, an undercoat layer 2 is provided on the conductive support 1 as necessary, and a photosensitive layer 6 containing a charge generating material and a charge transporting material is provided thereon. Then, if necessary, a surface protective layer 5 may be provided to form a negatively charged single-layer photoreceptor. In that case, X-type metal-free phthalocyanine is used as the charge generating material, and general formula (1) is used as the charge transporting material. A 1,1,4,4-tetraphenyl-1,3-butadiene compound represented by the formula (2) is dissolved and dispersed together with a polycarbonate resin having a repeating unit represented by the general formula (2) and other insulating resins as necessary. The photosensitive layer may be coated on the base support or undercoat layer to a thickness of 10 to 30 mm. The same insulating resin as described above can be used as needed, and the ratio thereof is also the same as described above.

Also, in this case, a surface protective layer may be provided, and a polycarbonate resin having a repeating unit represented by the general formula (2) may be used together with other binder resins as necessary in the surface protective layer. can. The same insulating resin as described above can be used as needed, and the ratio thereof is also the same as described above.

Further, in both the positively charged functionally separated type and the negatively charged single layer type, an undercoat layer can be provided as necessary, and the same material as described above can be used for this undercoat layer.

The electrophotographic photoreceptor obtained as described above exhibits high sensitivity and high durability in all cases.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example-1 X-type metal-free phthalocyanine (Fastogen Blu
e8120B, manufactured by Dainippon Ink & Chemicals) 4.1g
, 4.1 g of polyvinyl butyral (S-LEC BM-2, manufactured by Tanezu Kagaku ■), 200 g of cyclohexanone, and 650 g of glass beads (1φ) were placed in a sand mill, and dissolved and dispersed for 4 hours to prepare a paint for the charge generation layer. The paint was applied by dip coating to an aluminum cylinder (30φ) with a mirror-finished surface so that the film thickness after drying was 0.15-1, and then dried.

Next, 80 g of a 1,1,4.4-tetraphenyl-1,3-butadiene compound represented by formula (4), a polycarbonate Z resin having a repeating unit represented by formula (13) (number average molecular weight: 40,000 ) was dissolved in 450 g of dioxane to prepare a paint for a charge transport layer. The paint was applied by dip coating onto an aluminum cylinder previously coated with a charge generation layer so that the film thickness after drying would be 22-2, and then dried.

Using the drum-shaped electrophotographic photoreceptor thus produced, the electrophotographic properties were evaluated using a drum xerography tester. When charged with a corona voltage of -5.5 kV, the initial surface potential ν. was -780ν. The surface potential Vt after being left for 2 seconds in a dark place was -760ν. Then, a semiconductor laser with an emission wavelength of 790n- was irradiated, and the exposure amount was reduced by half E17. was determined to be 0.30 m/cm'', and the residual potential Vl was -10V.

Next, after repeating the above operation 50,000 times, vo.

V2. When El/O and Vll+ were measured, they were -760V, -740V, 0.32xJ/cs", -, respectively.
There was a voltage of 14.4V, and the performance of the photoreceptor had hardly deteriorated.

Next, the electrophotographic photoreceptor prepared in the same manner as above was attached to a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a print test was performed.

As a result, even after printing 50,000 sheets, almost no decrease in film thickness was observed, and no scratches that affected the images were found. Further, the image maintained a high image density and no deterioration was observed.

As described above, it was found that the electrophotographic photoreceptor according to the present invention has excellent sensitivity and durability.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

Examples-2 to 5 In Example-1, the compounds shown in Table 1 were used instead of the 1,1,4,4-tetraphenyl-1,3-butadiene compound represented by formula (4) as the charge transport material. A photoreceptor was produced in the same manner except for the use of the above material, and its performance was evaluated. The results are shown in Table 1.

As will be seen, the photoreceptor properties were excellent initially and even after 50,000 repetitions.

Further, even after a 50,000-sheet printing test with the photoreceptor mounted inside the printer, no decrease in film thickness was observed on any of the photoreceptors, and high image density was maintained.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

Table Examples 6 to 9 In place of the polycarbonate Z resin having the repeating unit represented by formula (13) in Example 1, polycarbonate Z resin having the repeating unit shown in Table 2 (all number average molecular weights are Table 2 Comparative Example-1 In Example-1, instead of the 1,1,4.4-tetraphenyl-1,3-butadiene compound represented by formula (4) as a charge transport material, a compound represented by the following formula (18) was used. A photoreceptor was prepared in the same manner except that the compound was used, and its performance was evaluated.

A photoreceptor was prepared in the same manner except that 40,000) was used, and its performance was evaluated. The results are shown in Table 2.

As will be seen, the photoreceptor properties were excellent initially and even after 50,000 repetitions.

Further, even after a 50,000-sheet printing test with the photoreceptor mounted inside the printer, no decrease in film thickness was observed on any of the photoreceptors, and high image density was maintained.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

The electrophotographic properties of the drum-shaped electrophotographic photoreceptor were evaluated using a drum xerography tester.

When charged with a corona voltage of 5.5 kV, the initial surface potential ν. was -780V. The surface potential v2 after being left in the dark for 2 seconds was -770V. Next, the transmission wavelength 7
Irradiate with a 90n- semiconductor laser and reduce the exposure amount by half El/
When I calculated 2, it was 0.70pJ/cs+! The residual potential V was -42.6V.

Next, after repeating the above operation 50,000 times, ν. .

When we measured Vt, E+/z, and Vm, we found that f
-760V, -720V, 0.94J/+:s
” -78, IV T: Yes, the performance of the photoreceptor was inferior compared to Example=1.

Next, the electrophotographic photoreceptor produced in the same manner as described above was mounted on a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a blint test was performed.

As a result, even after printing 50,000 sheets, there was almost no decrease in film thickness, and no scratches that affected the images were found, and the abrasion resistance was excellent, but the image density was low due to poor sensitivity. Met.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

Comparative Example-2 In Example-1, the following formula (1) was used instead of the polycarbonate 2 resin having the repeating unit represented by formula (13).
A photoreceptor was prepared in the same manner except that a polycarbonate A resin (number average molecular weight: 20,000) having the repeating unit shown in 9) was used, and its performance was evaluated.

C.I.

The electrophotographic properties of the drum-shaped electrophotographic photoreceptor were evaluated using a drum xerography tester.

When charged with a corona voltage of -5.5 kV, the initial surface potential v0 was -750 V. After being left in the dark for 2 seconds, the surface potential v2 was -730V. Next, a semiconductor laser with an emission wavelength of 790 nm is irradiated to reduce the exposure dose by half E1.
12 was found to be 0.31JIJ/ell'' and the residual potential Vt was -10.5V.

Next, after repeating the above operation 50,000 times, Vo.

V2. When Er/R+ Vjl was measured, they were -790V, -770V, and 0.33JIJ/CI+, respectively.
” -42.3V, and the performance of the photoreceptor is as in Example-1.
In particular, the residual potential tended to increase compared to the previous one.

Furthermore, even after a 50,000-sheet print test when installed inside a printer, the amount of decrease in film thickness was 7- at the initial stage, indicating poor abrasion resistance. In addition, scratches that affected the image were observed.

Furthermore, the image density began to decrease rapidly after 10,000 copies had been printed. As described above, the durability was poor.

Furthermore, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint gelled in a few days, and a stable paint could not be obtained.

Comparative Example 3 A photoreceptor was produced in the same manner as in Example 1, except that β-type metal-free phthalocyanine was used instead of X-type metal-free phthalocyanine as the charge generating material, and performance evaluation was performed.

The electrophotographic properties of the drum-shaped electrophotographic photoreceptor were evaluated using a drum xerography tester.

When charged with a corona voltage of -5.5 kV, the initial surface potential v0 was -780 V. The surface potential v2 after being left in the dark for 2 seconds was -770V. Next, a semiconductor laser with an emission wavelength of 790 nm is irradiated, and the exposure amount El is reduced by half.
/l was found to be 2.70JIJ/cap" and the residual potential V was -87.6V.

Next, after repeating the above operation 50,000 times, voVz, E
When +/z+ν was measured, each was -760V.
, -740V, 3.10#J/CI+" -18
0V, and the performance of the photoreceptor was inferior to that of Example-1.

Next, the electrophotographic photoreceptor produced in the same manner as above was attached to a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a print test was performed.

As a result, even after printing 50,000 sheets, there was almost no decrease in film thickness, and no scratches that affected the images were found, and the abrasion resistance was excellent, but the image density was low due to poor sensitivity. Met.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

Comparative Example 4 A photoreceptor was prepared in the same manner as in Example 1 except that indium phthalocyanine was used instead of the X-type metal-free phthalocyanine as the charge generating material, and performance evaluation was performed.

In the produced photoreceptor, pigment aggregates were present in some places on the charge generation layer, and a photoreceptor with uniform coating could not be obtained.

The electrophotographic properties of this photoreceptor were evaluated using a drum xerography tester. When charged with a corona voltage of -5.5kV, the initial surface potential v0 was -800V,
After being left in the dark for 2 seconds, the surface potential V2 was -600 ν, and the dark decay rate was as large as 25%. Next, a semiconductor laser having an emission wavelength of 790 nsi was irradiated, and the half-reduction exposure amount E+zz was determined to be 0.504/cio'', and the residual potential Vl was -11.OV.

Next, after repeating the above operation 50,000 times, vo.

V! +El/! When +vl was measured, they were -710V, -500V, and 0.55pJ/c, respectively.
-45.3V, and the performance of the photoreceptor was inferior to that of Example-1.

Next, the electrophotographic photoreceptor produced in the same manner as above was attached to a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a print test was performed.

As a result, black spots appeared in areas where the pigments on the photoreceptor were agglomerated, resulting in a decrease in image quality. In addition, even after printing 50,000 sheets, there was almost no decrease in film thickness, and no scratches that affected the image were found, and the abrasion resistance was excellent, but the image density was low due to poor sensitivity. there were.

Example-10 Polyamide resin (Amilan CM-8000, manufactured by Toshi ■) 10g was mixed with methanol/n-butanol (2/1)
A paint requiring undercoating was prepared by dissolving 200 g of the mixture.

The paint was applied by dip coating onto an aluminum cylinder (30φ) with a mirror-finished surface so that the film thickness after drying was 0.10J1 ml, and then dried.

Next, 20 g of X-type metal-free phthalocyanine, 80 g of a 1,1,4.4-tetraphenyl-1,3-butadiene compound represented by formula (9), and a polycarbonate Z resin having a repeating unit represented by formula (13) ( Number average molecular weight; 5
) 80g, dioxane 450g, glass peas (
1φ) was placed in a sand mill, and dissolved and dispersed for 4 hours to prepare a single layer paint. The undercoat layer was applied to an aluminum cylinder previously coated with an undercoat layer by dip coating so that the film thickness after drying was 25-2, and then dried.

Using the drum-shaped electrophotographic photoreceptor thus produced, electrophotographic properties were evaluated using a drum xerography tester. When it was charged with a corona voltage of -5.5, the initial surface potential v0 was -800V. The surface potential V after being left in the dark for 2 seconds was 770V. Next, we irradiated it with a semiconductor laser with a transmission wavelength of 790n+w and calculated the half-reduced exposure amount E+zz, which was 0.35JIJ/cs!
The residual potential V was -15.6.

Next, after repeating the above operation 50,000 times, vo.

When Vt, E+/z, and Vi were measured, they were -780V, -750V, and 0.37μJ/cm', respectively.
-23.8V, and the performance of the photoreceptor was hardly deteriorated.

Next, the electrophotographic photoreceptor produced in the same manner as above was attached to a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a print test was performed.

As a result, even after printing 50,000 sheets, almost no decrease in film thickness was observed, and no scratches that affected the images were found.

Further, when the storage stability of the paint for the charge transport layer at this time was investigated, the paint remained stable without gelling even after one month or more.

Comparative Example 5 A single-layer photoreceptor was produced in exactly the same manner as in Example 10, except that β-type metal-free phthalocyanine was used instead of X-type metal-free phthalocyanine as the charge generating material.

Using the drum-shaped electrophotographic photoreceptor thus produced, electrophotographic properties were evaluated using a drum xerography tester. When charged with a corona voltage of -5.5 kV, the initial surface potential v0 was -820V. The surface potential v2 after being left in the dark for 2 seconds was 800ν. Next, a semiconductor laser with an emission wavelength of 790 nm is irradiated, and the exposure amount E is reduced by half.
When l/□ was determined, it was 3.201 IJ/cm2'T: Yes, and the residual potential VR was -130V.

Next, after repeating the above operation 50,000 times, vo.

When Vt, E+yz, and VB were measured, they were -810V, -780V, and 4.10d/cm"-, respectively.
There was a voltage of 270V, and the performance of the photoreceptor was inferior to that of Example-10.

Next, the electrophotographic photoreceptor produced in the same manner as above was attached to a commercially available laser beam printer using a reversal development method using a blade cleaning method, and a print test was performed.

As a result, even after printing 50,000 sheets, there was almost no decrease in film thickness, and no scratches that affected the images were found, and the abrasion resistance was excellent, but the image density was low due to poor sensitivity. Met.

Furthermore, when the storage stability of the paint for the charge transport layer at this time was investigated, it was found that the paint remained stable without gelling even after one month or more.

〔Effect of the invention〕

X-type metal-free phthalocyanine as a charge generating material, and 1,1°4.4- shown in the general 2 (1) above as a charge transporting material.
The electrophotographic photoreceptor of the present invention, which contains a tetraphenyl-1,3-butadiene compound and a polycarbonate resin having repeating units represented by general 2 (2) above as a binder resin, has a stable initial potential and a dark potential. The attenuation rate is small,
It has high sensitivity. In addition, the deterioration of the material due to repeated use is small (and it is highly durable. Therefore, electrophotographic methods can be applied to copiers and various printers (laser beam printers, optical printers, LED printers, liquid crystal printers, etc.), etc.). It can be suitably used as a photoreceptor for devices.

Moreover, a paint using a polycarbonate resin having the repeating unit shown in General 2 (2) has excellent storage stability.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a negatively charged function-separated electrophotographic photoreceptor, FIG. 2 is a schematic cross-sectional view of a negatively charged single-layer electrophotographic photoreceptor,
FIG. 3 is a schematic cross-sectional view of a positively charging function-separated type electrophotographic photoreceptor. 1; Conductive support 2; Subbing layer 3; Charge generation layer 4; Charge transport layer 5; Surface protective layer 6; Photosensitive layer Fig. 1 Fig. 2

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a conductive support, a charge generating material, and a charge transporting material as essential components, wherein the charge generating material is an X-type metal-free phthalocyanine, and the charge transporting material is a compound of the general formula ( 1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (In the formula, R_1 represents a di-lower alkylamino group, and R_
2 represents a hydrogen atom or a di-lower alkylamino group. ) 1,1,4,4-tetraphenyl-1,3-
It contains a butadiene compound and has the general formula (
2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(2) (In the formula, R_3, R_4, R_5, R_6, R_7, R
_8, R_9, R_1_0 are the same or different,
Indicates a hydrogen atom, a halogen atom, or an alkyl group. ) An electrophotographic photoreceptor comprising a polycarbonate resin having a repeating unit represented by: 2. 1,1,4,4-tetraphenyl-1,3-butadiene compound represented by general formula (1) and general formula (2)
The electrophotographic photoreceptor according to claim 1, wherein a polycarbonate resin having a repeating unit represented by: is contained in the same layer.