JPH01147554A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain superior electrifiability, low residual potential and high sensitivity by forming a photosensitive layer containing a specified squarylium compound on a conductive substrate. CONSTITUTION:The photosensitive layer formed on the conductive substrate contains at least one of the squarylium compounds represented by formula I in which R1 is 1-20C alkyl or phenyl; R2 is H, OH, CH3, COOH, halogen, trifluoromethyl, alkylated or phenylated carbonamide or such sulfonamide; each of X1 and X2 is a group of formula II and III; and Z is an atomic group necessary to form a ring; and each of R2 and R3 is a benzyl group substituted by a specified group, thus permitting potential acceptance and sensitivity to be enhanced and residual potential to be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific squarylium compound.

Conventional technology Conventionally, inorganic photoconductive substances such as amorphous selenium, selenium alloys, cadmium sulfide, and zinc oxide, and organic photoconductive substances such as polyvinyl carbazole and polyvinyl carbazole derivatives have been used as electrophotographic photosensitive materials. is widely known.

Organic photoconductive materials are more transparent and transparent than inorganic ones.
It has the advantage of being excellent in terms of film-forming properties, flexibility, and manufacturability.

Problems to be Solved by the Invention The reason why organic photoconductive materials have not been used in electrophotographic photoreceptors despite having such many advantages is that inorganic photoconductive materials lack sensitivity and durability. It was to be inferior.

Therefore, the present invention has been made in view of the above-mentioned drawbacks when using an organic photoconductive substance, and its object is to provide a highly sensitive electrophotographic photoreceptor.

Means for Solving the Problems The electrophotographic photoreceptor of the present invention has the following -
Throwing money (I> [In the formula, R1 represents an alkyl group or phenyl group having 1 to 20 carbon atoms, and R2 is a hydrogen atom, a hydroxyl group, a methyl group, a carboxyl group, a halogen atom, a trifluoromethyl group, an alkyl group, or a phenyl group. substituted carbonamide group,
or alkyl or phenylene (wherein Z represents an atomic group necessary to form a ring, R3 and R4 are each independent of each other, and an alkyl group having 1 to 2 G carbon atoms,
Unsubstituted benzyl group, or alkyl group having 1 to 6 carbon atoms, hydroxyl group, alkoxy group having 1 to 4 carbon atoms, halogen atom, nitro group, cyano group, flukoxycarbonyl group having 1 to 4 carbon atoms, and trifluoromethyl group・Represents a benzyl group substituted with one or more substituents selected from the group consisting of)
represents. However, it is characterized by forming a photosensitive layer containing a squarylium compound represented by (), which does not mean the same thing.

The present invention will be explained in detail below.

The above-mentioned coin used in the electrophotographic photoreceptor of the present invention (
Representative squarylium compounds represented by I) include squarylium compounds represented by (II) below.

υ (In the formula, R5 represents a hydrogen atom, a methyl group, a fluorine atom, or a hydroxyl group.) Specific examples of the squarylium compounds represented by the above-mentioned I> used in the present invention include the following. It will be done.

O The squarylium compound represented by the above-mentioned coin (I>) is
It is manufactured as follows.

That is, 3,4-dichloro-3-cyclobutene 1°2-dione and the following -Isen (I[I) <h-x2. .

(In the formula, R and x2 represent the same meanings as above) are reacted in a suitable solvent such as methylene chloride to form the following formula (IV) (wherein, R2 and ) to produce a chlorocyclobutenedione derivative represented by
Then, the chlorocyclobutenedione derivative is hydrolyzed to produce a hydroxycyclobutenedione derivative represented by the following formula (V) (wherein R2 and x2 have the same meanings as above),
The hydrocyclobutenedione derivative is prepared as follows:
l) A compound represented by (wherein R1 and xl have the same meanings as above) and a suitable solvent, for example, an aliphatic alcohol having 4 to 8 carbon atoms such as n-butyl alcohol and n-heptyl alcohol, Alternatively, it can be produced by heating and reacting this with an aromatic hydrocarbon such as benzene or toluene in a mixed solvent.

A synthesis example thereof is shown below, but other squarylium compounds can also be produced in the same manner.

Synthesis example 3.4-dichloro-3-cyclobutene 1,2-dione
1.51 g (0.1 mol), N,N-dimethylaniline 60d (0.5 mol) and boron trifluoride ethyl ether complex 13rnll (0.1 mol) were dissolved in methylene chloride God, and the mixture was heated at room temperature for 5 hours. The mixture was stirred and the reaction was carried out. After the reaction was completed, the reaction mixture was washed with dilute hydrochloric acid and then with water, and separated and purified using column chromatography to obtain 19.0 g (yield: 81%) of a chlorocyclobutenedione compound represented by the following structural formula.

Obtained chlorocyclobutenedione compound 19.09
(0.08 mol), add 75 d of acetic acid and 25 ml of water,
After heating under reflux for 1 hour, the mixture was allowed to cool, and the deposited precipitate was filtered off to obtain 17.2 g (yield: 98%) of a hydroxycyclobutenedione compound represented by the following structural formula. Melting point:
mp=240″C (gradual decomposition).

Obtained hydroxycyclobutenedione compound 1.00
9 (4°60 mmol) and 3-acetylamino-N,
After heating and stirring 1.649 (9.20 mmol) of N-dimethylaniline in butanol ioo.g for 5 hours, the precipitated crystals were separated by filtration and washed with methanol and diethyl ether to form a product represented by the following structural formula. 1.60$ (yield 92%) of squarylium compound was obtained.

Melting point: mp=266°C (decomposition).

In the present invention, the squarylium compound is contained in a photosensitive layer provided on a conductive support, and the electrophotographic photoreceptor of the present invention includes, for example: (1) on a conductive support;
A photosensitive layer comprising a squarylium compound dispersed in a binder resin containing a charge transport substance; (2) A photosensitive layer formed by dispersing a squarylium compound and a charge transfer complex in a binder resin on a conductive support; layered, and 3)
It can be broadly classified into those in which a charge generation layer containing a squarylium compound and a charge transport layer containing a charge transport substance are provided on a conductive support.

Examples of the conductive support in the electrophotographic photoreceptor of the present invention include a metal plate made of aluminum, nickel, chromium, stainless steel, etc., a metal drum, or a plastic film provided with a metal foil and a thin film of metal or other conductive substance. Paper or plastic film coated with or impregnated with a conductivity imparting agent is used.

In the present invention, when the squarylium compound is dispersed in the binder resin in the photosensitive layer formed on the conductive support, the squarylium compound is fine particles having a particle size of 3 μm or less, preferably 0.3 μm or less. It is preferable that the compounding amount is 20% to 90% by weight based on the photosensitive layer.

Binder resins include polystyrene, silicone resins, polycarbonate, acrylic resins, methacrylic resins, polyesters, vinyl polymers such as polyvinyl butyral, celluloses such as cellulose esters, cellulose ethers, alkyd resins, etc. can be used.

Examples of the charge transport substance used in the electrophotographic photoreceptor of the present invention include N-methyl-N-phenylhydrazino-3-methylidene-9-ethylcarbazole-3-methylidene-9-ethylcarbazole, N;

N-diphenylhydrazino-3-methylidene-9-methylcarbazolesaldehyde-N. N-diphenylhydrazone, p-diethylaminobenzaldehyde-N,N-di(p-methoxyphenyl)hydrazone, p-diethylaminobenzaldehyde-N-(α-naphthyl)-N-7enylhydrazone, β. Hydrazones such as β-di(4-methoxyphenyl)acroleindiphenylhydrazone, 1-7enyl-3-(p-diethylaminostyryl)-5-(p
-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[quinolyl(2>]-3
Pyrazolines such as -(p-diethylaminostyryl)-5- (p-diethylaminophenyl)pyrazoline, 2
-(p-dipropylaminophenyl)-4-(D-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(p-diethylaminostyryl)-6
-Oxazole compounds such as dinithylaminobenzoxazole, 2,5-bis(p-diethylaminophenyl)-1.3.4-oxadiazole, 2.

Oxadiazole compounds such as 5-bis(4'-diethylamino-2'-methylphenylene/L/)-1,3,4-oxadiazole, bis(4-diethylamino-2-
Triarylmethane compounds such as (methylphenyl)-phenylmethane, triphenylamine, 2.4', 4"
-trimethyltriphenylamine, 1,1-bis[4
'-N,N-di(p-methylphenyl)aminophenylcocyclohexane and other triarylamine compounds, 5
-(Anthracene compounds such as p-diethylaminostyrylanthracene, stilbene compounds such as α-phenyl-4'-N, N-diphenylaminostilbene, 4'-N, N-di(9-methoxyphenyl)aminostilbene, N, N'-diphenyl=N, N'-bis(3-methylphenyl)-N.

1'-biphenyl]-4,4'-diamine, 3゜3'-
Dimethyl-N,N,N',N'-tetrakis(4-methylphenyl)-[1,1'-biphenyl]-4,4'
Examples include benzidine compounds such as -diamine, which are incorporated into the binder resin. Zaranimata, poly-N-
Vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylanthracene, poly-9-vinylphenylanthracene, polyvinylpyrene, polyvinylacridine, polyvinylacenaphthylene, polyglycidylcarbazole, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, etc. Examples include photoconductive polymers, which may themselves form a layer.

In the present invention, it is preferable that the photosensitive layer has a laminated structure because the sensitivity of the electrophotographic photoreceptor is high and the residual potential is low.

In this case, the charge generation layer may be formed by dispersing the squarylium compound in the binder resin as described above.
It may also be formed by sublimation or vapor deposition of squarylium compounds. Further, either a charge generation layer or a charge transport layer may be provided as an upper layer, and when the charge generation layer is provided as an upper layer, the electrophotographic photoreceptor is of a positively charged type, and the charge transport layer is provided as an upper layer. When provided, it can be used as a negatively charged type.

In the electrophotographic photoreceptor of the present invention, an adhesive layer may be provided between the photosensitive layer and the conductive support.

The adhesive layer is made of commonly used synthetic resin such as polyester, and usually has a film thickness of 0.5 to 5.
Formed instantly.

Example Next, the present invention will be explained by examples.

Example 1 To 11 parts by weight of the above-mentioned exemplified compound, 1 part by weight of polyester resin (Atohetsusib 49000 manufactured by DuPont) and 10 parts by weight of tetrahydrofuran were added, and the mixture was ground in a ball mill for 4 hours, and the mixed dispersion was coated with aluminum using a bar coater. was coated on a polyester film [Metal Me (registered trademark), manufactured by Toshi Co., Ltd.] on which the mixture had been vapor-deposited, and dried at 70° C. for 5 hours to form a charge generation layer with a thickness of 1 m.

N,N'-diphenyl-N on this charge generation layer.

N'-bis-(3-methylphenyl)-N.

1'-piphenyl]-4,4'-diamine 1 part by weight, polycarbonate resin [manufactured by others, Panlite (registered trademark)]
] A homogeneous solution consisting of 11 parts by weight of tetrahydrofuran and 10 parts by weight was applied using an applicator and heated to 16 parts by weight at 70°C.
A charge transport layer having a thickness of 22 mm was formed by drying for an hour to prepare an electrophotographic photoreceptor.

Next, electrostatic copying paper test@device (manufactured by Kawaguchi Electric, Nirecrotrostatic Paper Analyzer 5P-428>
After applying corona discharge of −6 KV to negatively charge the layer using The surface potential is VD when left in the dark.
The exposure amount E1/2, which is 172, was determined. The result is
The initial charging potential Vo = 960V, the potential after being left in the dark for 2 seconds VDDP = 920V% El/2-2.8/Lztx.sec, and the residual potential R9-0V.

In addition, in order to demonstrate that the material has extremely excellent sensitivity to long wavelength light, the following measurements were performed. After charging the above electrophotographic photoreceptor by performing corona discharge in a dark place, it was electrified using a monochromator at 800 nm under 1 μW.
The electrophotographic photoreceptor was irradiated with monochromatic light of /a/l. Then, the time until the surface potential reached 172 was measured, and the exposure amount was determined. As a result, the exposure amount was 13.2 ergs/cri
Met.

Examples 2 to 5 Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that Exemplified Compounds 2.4, 19 and 25 were used in place of Exemplified Compound 1, and the same procedures were carried out. It was evaluated as follows. The results are shown in Table 1.

Table 1 Effects of the Invention Since the electrophotographic photoreceptor of the present invention has a photosensitive layer using the squarylium compound shown in the above-mentioned (1),
It has excellent charging properties, low residual potential, and is superior in sensitivity compared to electrophotographic photoreceptors using conventional organic photoconductive substances.

Patent applicant Fuji Xerox Co., Ltd. Agent
Patent attorney Tsuyoshi Seibe

Claims (2)

[Claims] (1) On the conductive support, the following general formula (I)▲mathematical formula,
There are chemical formulas, tables, etc. ▼ (I) [In the formula, R_1 represents an alkyl group having 1 to 20 carbon atoms or a phenyl group, and R_2 represents a hydrogen atom, hydroxyl group, methyl group, carboxyl group, halogen atom, trifluoromethyl represents an alkyl- or phenyl-substituted carbonamide group, or an alkyl- or phenyl-substituted sulfonamide group,
and
_3 and R_4 are each independent of each other, and are an alkyl group having 1 to 20 carbon atoms, an unsubstituted benzyl group,
or an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms;
alkoxy group, halogen atom, nitro group, cyano group,
represents a benzyl group substituted with one or more substituents selected from the group consisting of an alkoxycarbonyl group having 1 to 4 carbon atoms and a trifluoromethyl group. However, the group ▲There are mathematical formulas, chemical formulas, tables, etc.▼ and the group ▲There are mathematical formulas, chemical formulas, tables, etc.▼ do not mean the same thing.] An electrophotographic photoreceptor featuring: (2) The squarylium compound is represented by the following general formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, R_5 represents a hydrogen atom, a methyl group, a fluorine atom, or a hydroxyl group.) An electrophotographic photoreceptor according to claim 1, characterized in that: