JPH01147553A - 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 H, methyl, carboxy, 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 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 -
Maximum (I> [wherein R1 is a hydrogen atom, a methyl group, a carboxyl group,
represents a halogen atom, a trifluoromethyl group, an alkyl- or phenyl-substituted carbonamide group, or an alkyl- or phenyl-substituted sulfonamide group, and x1 and x2 are each independent of each other, (in the formula, Zo represents an atomic group necessary to form a ring,
R and R3 are each independent of each other,
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, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, a cyano group having 1 to 4 carbon atoms A photosensitive layer containing a squarylium compound represented by a benzyl group substituted with at least one selected from the group consisting of a flukoxycarbonyl group and a trifluoromethyl group is formed. .

The present invention will be explained in detail below.

The maximum (maximum) used in the electrophotographic photoreceptor of the present invention
Representative squarylium compounds represented by I) include squarylium compounds represented by -maximum (n) below.

(In the formula, R4 represents a hydrogen atom, a methyl group, a fluorine atom, or a hydroxyl group.) Specific examples of the squarylium compound represented by -maximum (I>) used in the present invention include the following.

U 工〇− ° ○ 、○−2 え○− 7−9−1: “ ○ , ○−0 “ 0 . ○- The squarylium compound represented by the above general formula (I>) is
It is manufactured as follows.

That is, 3,4-dichloro-3-cyclobutene 1°2-dione and a compound represented by the following maximum (I) (in the formula, x1 represents the same meaning as above) are mixed in a suitable solvent such as chloride. React in methylene,
A chlorocyclobutenedione derivative represented by the following maximum (1■) (in the formula, x1 represents the same meaning as above) is produced, and then the chlorocyclobutenedione derivative is hydrolyzed to obtain the following maximum (1). v) Produce a hydroxycyclobutenedione derivative represented by has the same meaning as above] and a suitable solvent, such as an aliphatic alcohol having 4 to 8 carbon atoms such as n-butyl alcohol or n-heptyl alcohol, or an aromatic alcohol such as benzene or toluene. It can be produced by heating and reacting in a mixed solvent with a hydrocarbon.

Typical synthesis examples thereof are shown below, but other squarylium compounds exemplified above can also be produced in the same manner.

Synthesis example 3.4-dichloro-3-cyclobutene 1,2-dione
3.64y (24,1 mmol), 7.2 g (48,0 mmol) of 3,5-difluoro-N,N-dimethylaniline and boron trifluoride ethyl ether name 7.2
q (48.0 mmol) of methylene chloride 15rd!
The mixture was dissolved in water and stirred at air temperature for 24 hours to carry out a reaction.

After the reaction is completed, the reaction mixture is washed with dilute salt and then with water,
A chlorocyclobutenedione compound represented by the following structural formula was prepared using column chromatography.
2.319 (yield 35%) is jq.

Obtained chlorocyclobutenedione compound 2.010
110 ml of vinegar and 5 tbsp of water were added to g (7.40 mmol), heated under reflux for 2 hours, allowed to cool, and the deposited precipitate was filtered to obtain hydroxycyclobutenedione compound 1 represented by the following structural formula. .610 g (yield: 1.50 g (5,92 mmol) of the hydroxycyclobutenedione compound obtained and 3-hydroxy-N.

After stirring 0.829 (6.1 mmol) of N-dimethylaniline in butanol 6 (7) at zero heat for 20 hours, the precipitated blue-green crystals were filtered and washed with methanol and diethyl ether to give the following structure. 1.98 g (yield 90%) of a squarylium compound represented by the formula was obtained. Melting point m, p, = 302°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 G)
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.

The conductive support for the electrophotographic photoreceptor of the present invention may be a metal plate made of aluminum, nickel, chromium, stainless steel, etc., a metal drum, or a plastic film provided with metal foil and a thin film of metal or other conductive material. A paper or plastic film shade 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 has a particle size of 3 moles or less, preferably 0.3 moles or less. Dispersed as fine particles,
The blending amount thereof is preferably 20% to 90% by weight based on the photosensitive layer.

Binder resins include polystyrene, silicone resins, polycarbonates, acrylic resins, methacrylic resins, polyesters, vinyl polymers such as polyvinyl butyral, celluloses such as cellulose esters,
Cellulose ether, alkyd resin, 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-ethyl! Levazol, N
, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, p-diethylaminobenzaldehyde-N,N-diphenylhydrazone, p
-diethylaminobenzaldehyde-N,N-di(p-
1-
Phenyl-3-(p-diethylaminostyryl)-5-
(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[quinolyl(2>]
-3-(p-diethylaminostyryl)-5- (p-
Pyrazolines such as diethylaminophenyl)pyrazoline, 2-(p-dipropylaminophenyl)-4-(p-
dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(p-diethylaminostyryl)
-Oxazole compounds such as 6-dinithylaminobenzoxazole, 2,5-bis(p-diethylaminophenyl)-1.3.4-oxadiazole, 2.

Oxadiazole compounds such as 5-bis(4'-diethylamino-2'-methylphenyl)-1,3,4-oxadiazole, thoria such as bis(4-diethylamine-2-methylphenyl)-phenylmethane, etc. Rylmethane compounds, triphenylamine, 2.4',4''-trimethyltriphenylamine, 1,1-bis[4'-N,
Triarylamine compounds such as N-di(p-methylphenyl)aminophenylcocyclohexane, 5-(p
- Anthracene compounds such as diethylaminostyryl anthracene, stilbene compounds such as α-phenyl-4'-N, N-diphenylaminostilbene, 4'-N, N-di(p-methoxyphenyl)aminostilbene, N
, N'-diphenyl-\N +-bis(3-methylphenyl)-[1゜1'-biphenyl]-4,4'-diamine, 3゜3'-dimethyl-N, N, N', N'
-tetrakis(4-methylphenyl)-[1,1'-
Examples include benzidine compounds such as [biphenyl]-4,4'-diamine, which are contained in the binder resin. In addition, photoconductive materials such as poly-N-vinylcarbazole polyvinylanthracene, poly-9-vinylphenylanthracene, polyvinylpyrene, polyvinylacridine, polyvinylacenaphthylene, polyglycidylcarbazole, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, etc. The polymer is destroyed,
These may form a layer by themselves.

In the present invention, it is preferable that the photosensitive layer has a laminated groove 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; when a charge generation layer is provided as an upper layer, the electrophotographic photoreceptor is of a positively charged type, and when a charge transport layer is provided as an upper layer 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.
It is formed to about um.

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

Example 1 To 1 part by weight of the Exemplified Compound 1, 1 part by weight of polyester resin (DuPont, Adhesive 49000) and 1 part of tetrahydrofuran 10I 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. The mixture was coated on a polyester film [Metal Me (registered trademark) manufactured by Toshi Co., Ltd.] 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)-[1.

1'-biphenyl]-4.4'-diamine single layer, polycarbonate resin [manufactured by others, Panlite (registered trademark)]
] A homogeneous solution consisting of 11 parts by weight and 10 parts by weight of tetrahydrofuran was applied using an applicator, and heated at 70°C for 5 minutes.
A charge transport layer having a thickness of 22 μm was formed by drying for a period of time, and an electrophotographic photoreceptor was prepared.

Next, electrostatic copying paper test bag @ (manufactured by Kawaguchi Electric, Nirecrotrostatic Paper Analyzer SP-428
), the photosensitive layer was negatively charged with -6 kV corona discharge, left in a dark place for 2 seconds, and then the photosensitive layer was irradiated with light using a tungsten lamp so that the surface illuminance was 10 lux. , its surface potential is V after being left in the dark
The upper half of the exposure amount, which is 172 of D, was determined. The results were as follows: initial charging potential Vo=1030V, after being left in the dark for 2 seconds (
DB position VDDP = 970V, El/2 = 2.
This occurred at a residual potential Rp-〇v.

In addition, in order to demonstrate that the material has extremely excellent sensitivity to long wavelength light, the following measurements were performed. After the above electrophotographic photoreceptor was charged by corona discharge in a dark place, the electrophotographic photoreceptor was irradiated with monochromatic light of 1 μm resolution under 800 nm using a monochromator. Then, the time until the surface potential reached 172 was measured, and the exposure amount was determined. As a result, the exposure amount was 9.9 ergs/cm.

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. evaluated. The results are shown in Table 1.

Table 1 Effects of the Invention The electrophotographic photoreceptor of the present invention has a photosensitive layer using a squarylium compound having the structure represented by the above-mentioned -maximum (I>). Compared to electrophotographic photoreceptors using photoconductive materials, it has superior sensitivity.

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 is a hydrogen atom, a methyl group, a carboxyl group, a halogen atom, a trifluoromethyl group, an alkyl- or phenyl-substituted carbonamide group, or an alkyl- or phenyl-substituted sulfonamide group. X_1 and X_2 are each independent of each other, and the group ▲ has a mathematical formula, chemical formula, table, etc. ▼ or the group ▲ has a mathematical formula, chemical formula, table, etc. Represents the atomic group necessary to form R
_2 and R_3 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 at least one selected from the group consisting of an alkoxycarbonyl group having 1 to 4 carbon atoms and a trifluoromethyl group] A photosensitive layer containing a squarylium compound represented by is formed. An electrophotographic photoreceptor characterized by: (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_4 represents a hydrogen atom, a methyl group, a fluorine atom, or a hydroxyl group.) An electrophotographic photoreceptor according to claim 1, characterized in that: