JPH0566587A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the photosensitive body which has excellent stability to temp. and humidity, has a high electrification characteristic and is hardly degraded in photosensitivity in spite of repetitive use. CONSTITUTION:The electrophotographic layer formed on a conductive base contains the styryl group expressed by formula I. In the formula I, A and B are the same or different and are a hydrogen atom (excluding the case both A and B are the hydrogen atoms), an aryl group or heterocyclic group which may have a substituent or 1 to 4c alkyl group; R<1> denotes a hydrogen atom, 1 to 3C alkyl group, etc.; R<2> denotes a hydrogen atom, aryl group which may have a substituent, heterocyclic group, etc.; R<3> denotes an aryl group, heterocyclic group, etc., which may have a substituent; (n) signifies integer 1, and may form a ring with each other when (n) is 2 or 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoconductor, and more particularly to an electrophotographic photoconductor in which a specific styryl compound is contained in a photosensitive layer formed on a conductive support. is there.

[0002]

2. Description of the Related Art Conventionally, in electrophotographic technology, selenium, cadmium sulfide, amorphous silicon, zinc oxide, etc., which are inorganic substances, have been widely used in the photosensitive layer of electrophotographic photoreceptors. However, in recent years, much research has been conducted using an organic photoconductive material as an electrophotographic photoreceptor.

Here, the basic properties required for the electrophotographic photosensitive member are as follows: (1) High chargeability due to corona discharge in a dark place. (2) The resulting electric charge due to corona charging is less attenuated in a dark place. (3) The charge should be rapidly dissipated by the irradiation of light. (4) There is little residual charge after light irradiation. (5) Little increase in residual potential and decrease in initial potential due to repeated use. (6) There are few changes in electrophotographic characteristics due to temperature and humidity.

Conventional inorganic electrophotographic photoreceptors such as selenium and cadmium sulphide have the conditions as a photoreceptor in terms of basic properties, but they are problematic in production, for example, have strong toxicity and film formability. However, it has drawbacks such as difficulty in manufacturing, low plasticity, and high manufacturing cost. Furthermore, in the future, due to depletion of resources, these inorganic substances, whose production is limited, and also in terms of pollution due to toxicity,
The use of photoreceptors of inorganic to organic materials is desired.

In view of these points, electrophotographic photoreceptors made of organic substances have been actively researched in recent years,
As a result, electrophotographic photoreceptors using various organic substances have been proposed and some have been put into practical use. Generally speaking, organic type has better transparency, lighter weight and easier film formation than inorganic type, and has both positive and negative electrification properties. It has advantages such as being easy.

Typical examples of organic electrophotographic photoconductors that have been proposed so far include polyvinylcarbazole and dielectrics thereof, but these are not necessarily sufficient in film formability, plasticity, solubility, adhesiveness and the like. In addition, polyvinyl carbazole sensitized with pyrylium salt dye (Japanese Patent Publication No. Sho 48-25658) and polyvinyl carbazole and 2,4,7-trinitroflorenone sensitized (US Pat. No. 3,484). , 237), etc., but those satisfying the basic properties required for the above-mentioned photoreceptor, mechanical strength, high durability, etc. are still insufficient. Has not been obtained.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity and high durability. In particular, the photoreceptor of the present invention is to provide a photoreceptor having excellent stability with respect to temperature and humidity, high charging characteristics, and substantially no deterioration in photosensitivity even after repeated use.

As a result of research on the photoconductive substance having the above-mentioned high sensitivity and high durability, the present inventors have found that the novel styryl compound represented by the general formula (I) is effective. The present invention has been reached. The styryl compound of the general formula (I) according to the present invention is usually synthesized in the following synthetic process.

Various substituted benzaldehydes or various substituted phenyl ketone derivatives are reacted with N-phenyl-N-substituted hydrazine to obtain N-phenyl-N-substituted hydrazones (structure (III)).

[0010]

[Chemical 3]

The N-phenyl-N-substituted hydrazone derivative represented by the formula (III) thus obtained is subjected to a formylation substitution reaction with phosphorus oxychloride and dimethylformamide or phenylmethylformamide to give a benzaldehyde derivative (general formula). (IV)) is obtained.

[0012]

[Chemical 4]

The benzaldehyde derivative thus obtained is modified with the Bittich reagent (formula (V)) having various substituents.
The styryl compound (I) of the present invention by reacting with
Can be obtained.

[0014]

[Chemical 5]

The symbols in the above formulas (III) to (V) are as follows:
It has the same meaning as the definition in formula (I). Here, each substituent will be described. As R ¹ , an alkyl group such as a methyl group, an ethyl group, an n-propyl group and an isopropyl group, an alkoxy group such as a methoxy group, an ethoxy group and a propoxy group, a halogen such as fluorine and chlorine. The electron-donating substituent was effective in the general formula. R ² is hydrogen,
Phenyl group, p-tolyl group, p-methoxyphenyl group,
An aryl group such as a 3,5-xylyl group, a 1-pyridyl group,
Examples thereof include heterocyclic groups such as N-ethyl-3-carbazole group and aralkyl groups such as benzyl group, p-methylbenzyl group and p-methoxybenzyl group.

R ³ is an alkyl group such as methyl group, ethyl group or propyl group, phenyl group, p-tolyl group, m-
Examples thereof include aryl groups such as tolyl group, p-chlorophenyl group, 3,5-xylyl group and p-methoxyphenyl group, and aralkyl groups such as p-methylbenzyl group and benzyl group. Examples of A and B include aryl groups such as phenyl group, 1-naphthyl group and p-tolyl group, heterocyclic groups such as 1-pyridyl group, alkyl groups such as methyl group and ethyl group, and especially A,
Compounds in which either B was a phenyl group and a phenyl group substituted with an electron donating substituent were effective.

Specific examples of the styryl compound of the present invention represented by the general formula (I) include those having the structures shown in Table 1. The styryl compound of the present invention is limited thereby. It is not something that will be done.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

[Table 5]

[0023]

[Table 6]

Among these exemplified compounds, those having excellent electrophotographic properties, cost and synthetic properties, R ₁ is hydrogen and p-
Examples of the styryl compound include a methyl group and a p-methoxy group, R ² is hydrogen, a methyl group, an ethyl group, R ³ is a phenyl group, and A and B are a methyl group, a phenyl group, and a p-tolyl group. The electrophotographic photosensitive member according to the present invention can be obtained by containing one kind or two or more kinds of the compounds shown above. In addition, in some cases, other styryl compounds (eg, β-phenyl- [4- (dibenzylamino)] stilbene, β-phenyl- [4- (N-ethyl-N-phenylamino)] stilbene, β-phenyl −
[4- [di (p-methylphenyl) amino]] stilbene, 1,1-bis (4-diethylaminophenyl)-
4,4-diphenylbutadiene), a triphenylamine compound (for example, 4-methoxy-4 ′-(4-methoxystyryl) triphenylamine, 4-methoxy-4′-styryltriphenylamine) and the like can be contained. ..

Next, the specific synthesis of the styryl compound of the present invention will be described. Synthesis Example 1 (Exemplified Compound No. 1) Benzaldehyde and 1,1 diphenylhydrazine hydrochloride were reacted in ethanol using potassium acetate as a catalyst to give benzaldehyde diphenylhydrazone (melting point 11
8.0-120.0 ° C.). The hydrazone body thus obtained was formylated with dimethylformamide and phosphorus oxychloride to give a formyl body (melting point: 113.5 to 11).
5.0 ° C) is obtained. Next, this formyl compound and potassium t-
Exemplified Compound No. 1 (melting point: 118.5 to 119.5 ° C.) can be easily obtained by reacting butoxide and diethyl p-methylbenzylphosphonate in tetrahydrofuran at 0 ° C. The recrystallization solvent was ethanol.

Various methods are conceivable as a mode of using these styryl compounds as an electrophotographic photoreceptor. For example, a styryl compound and a sensitizing dye, if necessary, a chemical sensitizer or an electron-withdrawing compound is added and dissolved or dispersed in a binder resin to form a photoreceptor on a conductive support or , A carrier mainly composed of a sensitizing dye or an azo pigment, a pigment represented by a phthalocyanine pigment, on a conductive support in the form of a laminated structure capable of forming a carrier generation layer having a high charge carrier generation efficiency and a carrier transfer layer. If necessary, the styryl compound of the present invention may be added to the generating layer to add an antioxidant compound or an electron-withdrawing compound to dissolve or disperse it in a binder, and this may be used as a carrier transfer layer. It is possible to apply in any case.

In making photoreceptors using the compounds of the present invention, the aid of a polymeric film forming binder on a support such as a metal drum, metal plate, electrically conductive processed paper or plastic film. Borrow and make a film. In this case, in order to further increase the sensitivity, it is desirable to add a sensitizer and a substance that imparts plasticity to the polymerizable film-forming binder as described below to form a uniform photoreceptor film.

As these polymerizable film forming binders, various ones can be mentioned depending on the field of use. That is, in the field of photoconductors for copiers or printers,
Polystyrene resin, polyvinyl acetal resin, polysulfone resin, polycarbonate resin, polyphenylene oxide resin, polyester resin, alkyd resin, polyarylate resin and the like are preferable. These are alone or 2
You may use it in mixture of 2 or more types. Among them, polystyrene,
Resins such as polycarbonate, polyarylate, and polyphenylene oxide have a volume resistance value of 10 ¹³ Ω or more, and also have excellent film-forming properties and potential characteristics.

The amount of these binders to be added to the styryl compound of the present invention is 0.2 to 20 times by weight, preferably 0.5 to 5 times and not more than 0.5. In that case, the styryl compound is precipitated from the surface of the photoconductor, and if it is more than 5 times, the sensitivity is remarkably lowered. An alkaline binder is especially required for use in printing plates. The alkaline binder is an acidic group soluble in water or an alcoholic alkaline solvent (including mixed systems), such as an acid anhydride group, a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, or a sulfonimide group. Is a polymer substance having It is preferable that these alkaline binders usually have a high acid value of 100 or more.

The binder resin having a large acid value is easily dissolved or swells easily in an alkaline solvent. Examples of these binder resins include styrene: maleic anhydride copolymer, vinyl acetate: maleic anhydride copolymer, vinyl acetate: crotonic acid copolymer, methacrylic acid: methacrylic acid ester copolymer, phenol resin, methacrylic acid. Acid: styrene: methacrylic acid ester copolymer and the like. The ratio of these resins added to the photoconductive organic substance may be approximately the same as in the case of the photoconductor for copying machine.

The sensitizing dye added to the photosensitive layer is a triphenylmethane dye represented by methyl violet, crystal violet, night blue, Victoria blue, erythrosine, rhodamine B, rhodamine 3R, acridine orange. , Acridine dyes such as flapeosin, thiazine dyes such as methylene blue and methylene green, capri blue,
Oxazine dyes such as Meldola blue, other cyanine dyes, styryl dyes, pyrylium salt dyes,
There are thiopyrylium salt dyes. In the photosensitive layer, as photoconductive pigments that generate charge carriers with extremely high efficiency by light absorption, phthalocyanine-based pigments such as various metal phthalocyanines, metal-free phthalocyanines, halogenated metal-free phthalocyanines, perylene imides, and perylene anhydrides. Perylene pigments such as, bisazo pigments, azo pigments such as trisazo pigments, quinacridone pigments, and anthraquinone pigments.

In particular, those using a metal-free phthalocyanine pigment, a titanyl phthalocyanine pigment, a fluorene or a bisazo pigment containing a phlorenone ring, a bisazo pigment composed of an aromatic amine, or a trisazo pigment as a pigment which generates a charge carrier shows high sensitivity. Gives excellent electrophotographic photoreceptors. Also, the above-mentioned dye may be used as the charge carrier generating substance. These dyes may be used alone, but in many cases the coexistence of a pigment generates charge carriers with higher efficiency. In addition to the spectral sensitizers mentioned above, it becomes necessary to add various chemical substances for the purpose of preventing the increase of residual potential, the decrease of charging potential, the decrease of sensitivity, etc., due to repeated use. ..

As the substances to be added, 1-chloroanthraquinone, benzoquinone, 2,3-dichloronaphthoquinone, naphthoquinone, 4,4'-dinitrobenzophenone, 4,4'-dichlorobenzophenone, 4-nitrobenzophenone, 4- Nitrobenzalmalondinitrile, α-cyano-β- (p-cyanophenyl) ethyl acrylate, 9-anthracenylmethylmalondinitrile, 1-cyano-1- (p-nitrophenyl) -2-
Examples thereof include electron-withdrawing compounds such as (p-chlorophenyl) ethylene and 2,7-dinitrofluorenone.

In addition, an antioxidant, an anti-curl agent, a leveling agent, etc. can be added as an additive to the photoreceptor, if necessary. The styryl compound of the present invention is dissolved or dispersed in a suitable solvent together with the above-mentioned various additives according to the form of the photoreceptor, and the coating solution is applied onto the above-mentioned conductive support and dried. Manufacture the photoreceptor.

As the coating solvent, aromatic hydrocarbons such as methylene dichloroethane, benzene, toluene, xylene, and monochlorobenzene, solvents such as dioxane, dimethoxymethyl ether, dimethylformamide, etc., or a mixed solvent of two or more kinds, or If necessary, a solvent such as alcohols, acetonitrile and methyl ethyl ketone can be further added and used.

[0036]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Examples 1 to 5 An aluminum vapor-deposited polyester film (film thickness: 80 μ) was used as a support, and the following structural formula was applied to the support.

[0038]

[Chemical 6]

The bisazo pigment represented by is added to a 1% THF solution in which polyvinyl butyral resin (Eslec B manufactured by Nisshin Chemical Industry Co., Ltd.) is dissolved in the same amount as the resin by weight, and then in a paint conditioner (manufactured by Red Level Co.). Then, the glass beads having a diameter of 1.5 mm were dispersed together for about 2 hours, and the mixture was applied and dried by the doctor blade method. The film thickness after drying was 0.2μ.

On the pigment layer (charge generation layer), the exemplified compounds (No. 1, No. 18, No. 23, N) of the present invention are formed.
o. 59, No. 69) 1 g of each and a 15% solution of 1.2 g of polyarylate resin (U-100 manufactured by Unitika) dissolved in methylene chloride was applied using a squeegee doctor, and a resin-styryl compound solid solution phase (charge) with a dry film thickness of 25 μm was applied. A moving layer) was created.

The laminated electrophotographic photosensitive member thus prepared was used as an electrostatic recording paper testing apparatus (SP-428 manufactured by Kawaguchi Denki Co., Ltd.).
The electrophotographic durability was evaluated by. The measurement conditions are (applied potential -6
KV, static No3), the exposure amount E ₁₀₀ (lux seconds) required to attenuate from −700 V to −100 V by white light irradiation (irradiation light = 5 lux) and the initial potential V ₀ (−volt) were measured, The values are shown in Table 1.

Further, by using the same apparatus, charging-static elimination (static elimination light:
The initial potential V ₀ (−volt) and E ₁₀₀ (lux · second) were measured after performing the same operation 10,000 times with 1 cycle of irradiation with white light at 40 lux for 1 second), and V ₀ and E
Examine ₁₀₀ changes. The results are shown in Table 2.

[0043]

[Table 7] From Table 2, it was found that the styryl compound of the present invention had good sensitivity repeating characteristics.

Example 6 An x-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc., Fastgen Blue 8) was formed on a polyester film vapor-deposited on aluminum.
120) 0.4 g was added to 30 ml of an ethyl acetate solution in which 0.3 g of a vinyl chloride: vinyl acetate copolymer resin (Slex M, manufactured by Sekisui Chemical Co., Ltd.) was dissolved and dispersed in a paint conditioner for about 20 minutes to prepare a doctor blade method. And a charge generation layer was formed so that the film thickness after drying was 0.4 μm.

Exemplified Compound No. 63 is formed on the charge generation layer.
A polyarylate layer containing 50% by weight of the styryl compound was laminated to prepare a photoreceptor having a two-layer structure. When the energy (E ₅₀ ) required to reduce the potential to half and the initial potential (−V ₀ ) were obtained using the light of 780 nm spectrum of the present photoreceptor, V ₀ = 970 (−volt), E ₅₀ = 3.0 ( The photosensitive member had a very high sensitivity of erg / cm ² ) and a high charging property. In addition, Sharp laser printer (WD
-580P) was modified, the photosensitive member was attached to the drum portion, and continuous blank copying (Non Copy Aging) was performed 10,000 times, and then the degree of initial potential decrease and sensitivity decrease were examined. The results are V ₀ = 960 (-volt), E ₅₀ =
The value was 3.0 (ergs / cm ² ), which was almost unchanged from the first time.

Examples 7 to 10 Alumite processing of the aluminum substrate surface (alumite layer 7μ)
1 g of each styryl compound of the present invention on the above-mentioned support, 1.1 g of polyarylate resin represented by the following structural formula and N,
N-3,5-xylyl-3,4-xylyl-3,4
9,10-Perylene tetracarboxylic imide 0.15
g and an ultraviolet absorber of 0.05 g were dissolved in methylene chloride (the imide compound was partially dispersed) to apply a solution, and a single-layer photoconductor having a dry film thickness of 20 μm was obtained.

[0047]

[Chemical 7]

In this way, the electrophotographic characteristics of the photoconductor were measured by an electrostatic recording paper test device. The measurement conditions are (applied voltage +
It was performed at 5.5 KV and static No. 3). The exposure dose E ₁₀₀ (lux · sec) required to reduce from +700 V to +100 V by white light irradiation was measured, and the value is shown in Table 3. Also, the degree of decrease in sensitivity (E ₁₀₀ ) was shown in Table 3 after performing an empty copy test 10,000 times.

[0049]

[Table 8]

It has been found that the photoconductor using the styryl compound of the present invention is a photoconductor having excellent sensitivity and repeatability even in positive charging.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akiko Masuda 22-22 Nagaikecho, Abeno-ku, Osaka

Claims (4)

[Claims] 1. A photosensitive layer formed on a conductive support,
General formula (I): [In the formula, A and B are the same or different and each is a hydrogen atom (except when both A and B are hydrogen atoms), an aryl group which may have a substituent, or a substituent which may have a substituent. A good heterocyclic group or an alkyl group having 1 to 4 carbon atoms, R ¹ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halogen atom, and R ² is hydrogen. An atom, an aryl group which may have a substituent, a heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, or an alkyl group having 1 to 4 carbon atoms, R ³
Is an aryl group which may have a substituent, a heterocyclic group which may have a substituent, an aralkyl group which may have a substituent, or an alkyl group having 1 to 4 carbon atoms, and n Means an integer of 1, 2 or 3, respectively. However, n
When is 2 or 3, R ^{1 s} may be the same or different and may further form a ring. ] A styryl compound is contained, The electrophotographic photoreceptor characterized by the above-mentioned. 2. A styryl compound of general formula (I) has the formula (I
I) [Chemical 2] (Wherein a is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halogen atom, and b
Is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms
Is an alkoxy group or a halogen atom, and m is 1, 2
Or, it means an integer of 3, respectively. However, when m is 2 or 3, a may be the same or different and R ¹ ,
R ² , A and n have the same meaning as defined in formula (I). However,
When n is 2 or 3, R ¹ may be the same or different, and may further form a ring. The electrophotographic photosensitive member according to claim 1, which is the compound (1). 3. The electron according to claim 1, wherein the photosensitive layer formed on the conductive support contains a carrier transfer material and a carrier generation material, and the carrier transfer material is a styryl compound of the general formula (I). Photoreceptor. 4. A photosensitive layer formed on a conductive support comprises a laminate of a carrier generating layer containing a carrier generating substance and a carrier transporting layer containing a carrier transporting substance. The electrophotographic photosensitive member according to claim 1, which is a styryl compound represented by formula (I).