JPH04329547A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a sensitive body having high sensitivity and high durability by incorporating a specified nitrogen-contg. compd. CONSTITUTION:A nitrogen-contg. compd. represented by formula I is incorporated into a layer on an electric conductive substrate. In formula I, Z is a group of atoms required to form a carbon ring which may have a substituent or a hetero ring, R<1> is H, alkyl which may have a substituent, aralkyl, aryl or a heterocyclic group and R<2> is H, halogen, alkyl which may have a substituent, alkoxy, aralkyl, aryl or a heterocyclic group. A concrete example of the carbon ring formed by Z and two C atoms is a cyclopentene or cyclohexene ring, that of R is H or methyl and that of R is H or F. A sensitive body having high sensitivity, high durability and high stable potential by electrification and hardly lowering the sensitivity even after repeated use is obtd.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor characterized by containing a novel nitrogen-containing compound.

0002

[Prior Art] Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, and silicon have been known to be used as electrophotographic photoreceptors, and have been widely studied and put into practical use. . Although these inorganic materials have many advantages, they also have various disadvantages. For example, selenium has the disadvantage of difficult manufacturing conditions and is easily crystallized by heat or mechanical shock, while cadmium sulfide and zinc oxide have poor moisture resistance and durability. Regarding silicon, it has been pointed out that it lacks chargeability and is difficult to manufacture. Additionally, selenium and cadmium sulfide have toxicity issues.

On the other hand, organic photoconductive materials have good film-forming properties, excellent flexibility, light weight, and good transparency, and can be sensitive to a wide range of wavelengths using an appropriate sensitization method. Since it has advantages such as easy body design, its practical application is gradually attracting attention.

By the way, photoreceptors used in electrophotography are generally required to have the following basic properties. That is, (1) it has high chargeability against corona discharge in the dark, (2) there is little leakage (dark decay) of the obtained charged charge in the dark, and (3) the charged charge is reduced by light irradiation. (4) The residual charge after light irradiation is small.

However, although much research has been conducted to date on photoconductive polymers such as polyvinylcarbazole as organic photoconductive materials, these do not necessarily have sufficient film properties, flexibility, or adhesive properties. Moreover, it cannot be said that the above-mentioned basic properties as a photoreceptor are sufficiently provided.

On the other hand, with regard to organic low-molecular-weight photoconductive compounds, it is possible to create photoreceptors with excellent film properties, adhesion, flexibility, and other mechanical strengths by selecting the binder used to form the photoreceptor. Although it can be obtained, it is difficult to find suitable compounds that retain the properties of high sensitivity.

[0007] In order to improve this point, the carrier generation function and the carrier transport function are shared by different substances.
Organophotoreceptors with higher sensitivity characteristics have been developed. A feature of this kind of photoreceptor, which is called a functionally separated type, is that materials suitable for each function can be selected from a wide range, and a photoreceptor with arbitrary performance can be easily created, which has led to a lot of research. has been progressing.

[0008]

[Problems to be Solved by the Invention] As mentioned above, various improvements have been made in the production of electrophotographic photoreceptors, but the basic properties and high durability required for photoreceptors as listed above are still lacking. There is still not enough material available that satisfies these requirements. An object of the present invention is to provide an electrophotographic photoreceptor that has high sensitivity, high durability, high charging potential, almost no decrease in sensitivity even after repeated use, and stable charging potential. It is.

[0009]

[Means for Solving the Problems] As a result of research into photoconductive substances with high sensitivity and high durability, the present inventors discovered that a novel nitrogen-containing compound represented by chemical formula 1 is effective. , led to the present invention.

In formula 1, Z is an atomic group necessary to form a carbocycle or a heterocycle which may have a substituent,
R1 is a hydrogen atom, an alkyl group that may have a substituent, an aralkyl group, an aryl group, or a heterocyclic group; R2 is a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an alkoxy group , aralkyl group, aryl group,
Indicates a heterocyclic group.

Specific examples of the carbocycle or heterocycle formed by Z and two carbon atoms include a cyclopentene ring, a cyclohexene ring, a methylcyclohexene ring,
Phenylcyclohexene ring, cycloheptene ring, indene ring, methoxyindene ring, chloroindene ring, phenylthioindene ring, dihydronaphthalene ring, dimethyldihydronaphthalene ring, acenaphthylene ring, phenalene ring, phenanthrene ring, dihydrothiophene ring, dihydrofuran ring, indole ring, N-phenylindole ring, and the like. Specific examples of R1 include a hydrogen atom, an alkyl group such as a methyl group and an ethyl group, an aralkyl group such as a benzyl group, a β-phenylethyl group, and an α-naphthylmethyl group, a phenyl group, a methoxyphenyl group, a methylphenyl group, Examples include aryl groups such as chlorophenyl group and naphthyl group, and heterocyclic groups such as thienyl group, furyl group, pyridyl group, and carbazolyl group. Specific examples of R2 include a hydrogen atom, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, a benzyl group, and β-phenylethyl. group, aralkyl group such as α-naphthylmethyl group, aryl group such as phenyl group, methoxyphenyl group, methylphenyl group, chlorophenyl group, naphthyl group, heterocyclic group such as thienyl group, furyl group, pyridyl group, carbazolyl group, etc. can be mentioned.

Specific examples of the compound represented by formula 1 are shown below, but the present invention is not limited thereto.

[0013]

[Case 2]

[0014]

[Chemical formula 3]

[0015]

[C4]

[0016]

[C5]

[0017]

[C6]

[0018]

[C7]

[0019]

[Chemical formula 8]

[0020]

[Chemical formula 9]

[0021]

[Chemical formula 10]

[0022]

[Chemical formula 11]

[0023]

[Chemical formula 12]

[0024]

[Chemical formula 13]

[0025]

[Chemical formula 14]

[0026]

[Chemical formula 15]

[0027]

[Chemical formula 16]

[0028]

[Chemical formula 17]

[0029]

[Chemical formula 18]

[0030]

[Chemical formula 19]

[0031]

[C20]

[0032]

[C21]

[0033]

[C22]

[0034]

[C23]

[0035]

[C24]

[0036]

[C25]

[0037]

[C26]

[0038]

[C27]

[0039]

[C28]

[0040]

[C29]

[0041]

[C30]

[0042]

[Chemical formula 31]

[0043]

[C32]

[0044]

[Chemical formula 33]

[0045]

[C34]

[0046]

[C35]

[0047]

[C36]

[0048]

[C37]

[0049]

[C38]

[0050]

[C39]

[0051]

[C40]

[0052]

[C41]

[0053]

[C42]

[0054]

[C43]

[0055]

[C44]

[0056]

[C45]

[0057]

[C46]

[0058]

[C47]

[0059]

[C48]

[0060]

[C49]

[0061]

[C50]

[0062]

[C51]

[0063]

[C52]

[0064]

[C53]

[0065]

[C54]

[0066]

[C55]

Next, a specific synthesis example will be described. Synthesis Example (Synthesis of Exemplified Compound 29) β-tetralone (5.0 g) and N,N-diphenylhydrazine hydrochloride (7.5 g) were added to 3N hydrochloric acid (35 ml).
The mixture was heated under reflux for 1 hour. The product was extracted with ethyl acetate, purified by silica gel column chromatography, and then recrystallized from ethanol. Yield 5.3g Yield 52% Melting point 111.2-111.3℃

The electrophotographic photoreceptor of the present invention can be obtained by containing one or more nitrogen-containing compounds represented by Chemical Formula 1. Various types of photoreceptors are known, and any of them can be used. For example, there is one in which a photosensitive layer comprising a known charge generating substance, the compound of the present invention, and a film-forming binder resin is provided on a conductive support. Additionally, a laminated photoreceptor is known, in which a charge generation layer made of a charge generation substance and a binder resin and a charge transport layer made of the compound of the present invention and a binder resin are provided on a conductive support. There is. Either the charge generation layer or the charge transport layer may be the upper layer. As the support for producing the photoreceptor using the compound of the present invention, metal drums, metal plates, conductive treated paper, sheet-like, drum-like, or belt-like supports of plastic films are used. .

Various film-forming binder resins can be used to form the photosensitive layer on these supports depending on the field of use. For example, for use in photoreceptors for copying, examples include polystyrene resin, polyvinyl acetal resin, polysulfone resin, polycarbonate resin, polyester resin, polyphenylene oxide resin, polyarylate resin, acrylic resin, methacrylic resin, phenoxy resin, and the like. Among these, polystyrene resins, polyvinyl acetal resins, polycarbonate resins, polyester resins, polyarylate resins, and the like have excellent potential characteristics as photoreceptors. In addition, these resins are
They can be used alone or in combination of two or more as a copolymer.

The amount of these resins contained in the photosensitive layer is preferably 10 to 500% by weight, based on the compound of the present invention, and 5% by weight.
More preferably 0 to 150% by weight.

[0071] Some of these resins include tensile, bending,
Some materials are weak in mechanical strength such as compression. To improve this property, substances imparting plasticity can be added. Specifically, phthalate esters (e.g. DOP, DB
P, etc.), phosphate esters (e.g. TCP, TOP, etc.),
Examples include sebacic acid ester, adipic acid ester, nitrile rubber, and chlorinated hydrocarbons. If these substances are added in excess of the necessary amount, they will adversely affect the electrophotographic properties, so the proportion of these substances relative to the binder resin is preferably 20% or less.

[0072] In addition, antioxidants, anti-curling agents, and the like can be added as additives to the photoreceptor, if necessary.

As the charge generating substance used in combination with the compound of the present invention, inorganic compounds such as selenium, selenium-tellurium, amorphous silicon, benzopyrylium,
Examples include pyrylium dyes such as benzothiapyrylium, cyanine dyes such as thiacyanine and oxacyanine, squareryllium dyes, phthalocyanine pigments, anthanthrone pigments, indigo pigments, quinacridone pigments, and azo pigments.

[0074]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 1 part by weight of the azo pigment represented by Chemical Formula 56 and 1 part by weight of a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) were mixed with 100 parts by weight of tetrahydrofuran and dispersed together with glass beads for 2 hours using a paint conditioner device. The thus obtained dispersion was applied onto aluminum-deposited polyester using an applicator to form a charge generation layer having a thickness of about 0.2 μm. Next, the compound represented by Chemical Formula 29 was mixed with a polyarylate resin (U-polymer manufactured by Unitika) at a weight ratio of 1:1, a 10% solution was prepared using dichloroethane as a solvent, and a 10% solution was prepared on the film of the carrier-generating substance. This solution was applied using an applicator to form a carrier transport layer with a dry thickness of 20 μm. The laminated electrophotographic photoreceptor thus produced was evaluated for electrophotographic characteristics using an electrostatic recording tester (SP-428 manufactured by Kawaguchi Electric). Measurement conditions: Applied voltage -
6KV, static No. 3 (turntable rotation speed mode). As a result, the half-light exposure to white light during charging was 1.5 lux·sec, which was a very high sensitivity value.

[0076]

[C56]

Furthermore, using the same device, characteristics were evaluated for repeated use in which one cycle was charging and neutralization (static discharge light: 400 lux x 1 second irradiation with white light). When we calculated the change in the charging potential due to 1000 repetitions, we found that the initial potential at the 1000th time was -670V compared to the initial potential of -690V at the 1st time, indicating that the potential drop due to repetition was small and stable. Ta.

Examples 2 to 7 Laminated photoreceptors were prepared in the same manner as in Example 1, except that the compounds shown in Table 1 were used in place of the compounds used in Example 1. Using this photoreceptor, under the same conditions as in Example 1, the light half-reduction exposure amount E1/2 (lux/second) and the initial potential Vo (V) were obtained after the first and 1000th repetition.
was measured. The results are shown in Table 1.

[0079]

[Table 1]

*: (looks seconds)

Examples 8 to 14 Titanyloxyphthalocyanine was used as the charge generating substance. That is, 1 part by weight of this pigment and 1 part by weight of a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) were mixed with 100 parts by weight of tetrahydrofuran and dispersed together with glass beads for 2 hours using a paint conditioner device. The pigment dispersion thus obtained was applied onto the same support as in Example 1 using an applicator to form a carrier generation layer. The thickness of this thin film was about 0.2μ. Next, a carrier transport layer was formed using the exemplary compounds shown in Table 2 in the same manner as in Example 1, thereby producing a laminated photoreceptor. This photoreceptor was evaluated under the same measurement conditions as in Example 1. The results are shown in Table 2.

[0081]

[Table 2]

*: (looks seconds)

Comparative Examples 1 and 2 Photoreceptors were prepared in the same manner as in Example 1, except that Comparative Compounds No. 57 and No. 58 were used in place of the compounds used in Example 1, and their properties were evaluated. The results are shown in Table 3.

[0083]

[C57]

[0084]

[C58]

[0085]

[Table 3] *: (looks seconds)

[0086]

As is clear from the above, according to the present invention, an electrophotographic photoreceptor having high sensitivity and high durability can be provided.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor comprising a nitrogen-containing compound represented by the following chemical formula 1 on a conductive support. [Formula 1] (In Chemical Formula 1, Z is a group of atoms necessary to form a carbocycle or heterocycle that may have a substituent, R1 is a hydrogen atom, an alkyl atom that may have a substituent) group, aralkyl group, aryl group, or heterocyclic group, R2 is a hydrogen atom,
a halogen atom, an alkyl group that may have a substituent,
Indicates an alkoxy group, an aralkyl group, an aryl group, and a heterocyclic group. )