JPH09216877A - 9,9-Dimethylxanthene compound and electrophotographic photoreceptor using the compound - Google Patents

Abstract

(57) Abstract: A novel xanthene compound useful as a charge transport agent used in an electrophotographic photoreceptor and an electrophotographic photoreceptor using the compound. The following general formula (1) has an excellent charge transporting ability and can be widely used as a charge transporting material.
An electrophotographic photoconductor having a 9,9-dimethylxanthene compound represented by the following formula and a photosensitive layer containing the compound on a conductive support. Embedded image (In the formula, Ar ₁ represents an aryl group which may have a substituent, Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group which may have a substituent, or an anthrylene group, and X represents A hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent is represented, and Y represents an aryl group which may have a substituent.)

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel 9,9-dimethylxanthene compound useful as a charge transport agent used in an electrophotographic photoreceptor and an electrophotographic photoreceptor using the compound.

[0002]

2. Description of the Related Art An electrophotographic method is generally a method in which the surface of a photoconductor made of a photoconductive material is charged in the dark, for example, by corona discharge, and then exposed to the light to selectively dissipate the charge in the exposed area. It is a kind of image forming method in which an electrostatic latent image is dispersed to obtain an electrostatic latent image, which is visualized with toner, and then transferred and fixed on paper or the like to obtain an image. As the photoconductor, an inorganic photoconductor containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, or silicon as a main component, and a charge generating agent and a low-molecular weight or high-molecular weight charge transport agent in a binder resin There is an organic photoconductor using an organic compound dispersed in. Inorganic photoconductors have many advantages and have been widely used until now.For example, selenium is difficult to produce, its production cost is high, it is vulnerable to heat and mechanical shock, and it easily crystallizes, resulting in poor performance. Resulting in. Zinc oxide and cadmium sulfide have problems in moisture resistance and mechanical strength, and the dye added as a sensitizer is deteriorated by electrification and exposure, resulting in poor durability. Silicon is also difficult to manufacture and uses a highly irritating gas, so it is expensive and sensitive to humidity.

In recent years, organic photoreceptors using various organic compounds have been studied and widely used for the purpose of overcoming the drawbacks of these inorganic photoreceptors. Organic photoreceptors include a single-layer photoreceptor in which a charge generating agent and a charge transporting agent are dispersed in a binder resin, and a laminated photoreceptor in which a charge generating layer and a charge transporting layer are functionally separated. The function-separated type organic photoconductor has been extensively researched and widely used because of its wide choice of materials and the fact that a photoconductor having any desired performance can be produced relatively easily by combining them.

Examples of the charge generating agent include azo compounds,
Many organic compounds such as bisazo compounds, trisazo compounds, tetrakisazo compounds, thiapyrylium salts, squarylium salts, azurenium salts, cyanine dyes, perylene compounds, metal-free or metal phthalocyanine compounds, polycyclic quinone compounds, thioindigo compounds, or quinacridone compounds. Pigments and dyes have been proposed and put into practical use.

As the charge transfer agent, for example, Japanese Patent Publication No. 34-
Oxadiazole compounds described in JP-A-5466, JP-A-56
No. 123544, Oxazole Compound, Japanese Examined Patent Publication No. 5
JP-A 2-41880, Pyrazoline Compound, JP-B-55
-42380 gazette and Japanese Patent Publication No. 61-40104 gazette,
JP-B-62-35673, JP-B-63-3597
No. 6, hydrazone compound, Japanese Patent Publication No. 58-32372
Compounds disclosed in Japanese Patent Publication No. 63-18738, Japanese Patent Publication No. 63-19867, and Japanese Patent Publication No. 3-393.
No. 06 stilbene compound, JP-A-62-3025
For example, there is a butadiene compound disclosed in Japanese Patent No. Organic photoconductors using these charge-transporting materials have excellent properties and some have been put into practical use, but those that sufficiently satisfy the properties required for electrophotographic photoconductors have not yet been obtained. The current situation is not.

[0006]

The charge transfer agent used in the organic photoreceptor has not only the sensitivity and other characteristics as a photoreceptor, but also a chemical stability that withstands light, ozone, and electrical loads. Stability and durability are required so that the sensitivity does not decrease even after repeated use or long-term use. The object of the present invention is to use a novel 9,9-dimethylxanthene compound which is useful as a charge transfer agent capable of realizing an electrophotographic photoreceptor having a high sensitivity and a high durability and satisfying the characteristics of the photoreceptor, and the compound. An object is to provide a photoconductor for electrophotography.

[0007]

According to the present invention, a 9,9-dimethylxanthene compound represented by the following general formula (1) and a photosensitive layer containing the compound on a conductive support are provided. A photoconductor for electrophotography is provided.

[0008]

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[In the formula, Ar ₁ represents an aryl group which may have a substituent, and Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group or an anthrylene group which may have a substituent. , X represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Y represents an aryl group which may have a substituent or the following general formula (2 )

[0010]

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Alternatively, the following general formula (3)

[0012]

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(Wherein R ₁ represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, R ₂ represents a hydrogen atom, a halogen atom or a lower alkyl group, and Z represents a hydrogen atom or a substituent. Also represents a good aryl group, m and n
Represents an integer of 0 to 4. ). ]

In the present invention, the 9,9-dimethylxanthene compound represented by the general formula (1) used as a charge transport agent is a novel compound, and these compounds are
For example, a 2- (N, N-diphenylamino) -9,9-dimethylxanthene derivative is formylated to form a Wittig-Horner-Em with a corresponding phosphonate ester.
It is synthesized by the Mons reaction. Formylation is Vils
The general method is by the Meier reaction. For example, the following general formula (4)

[0015]

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[In the formula, Ar ₂ and Y are represented by the general formula (1).
Has the same meaning as ] The triarylamine compound represented by the formula [5] below is subjected to formylation with N, N-dimethylformaldehyde and phosphorus oxychloride.

[0017]

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[In the formula, Ar ₂ and Y are represented by the general formula (1)
Has the same meaning as ] The aldehyde compound represented by this is obtained. Next, the following general formula (6) is added to this aldehyde compound.

[0019]

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[In the formula, Ar ₁ and X have the same meanings as in the general formula (1), and R ₄ represents a lower alkyl group. ] It reacts with the phosphonate represented by the above formula to obtain the 9,9-dimethylxanthene compound of the present invention represented by the general formula (1).

The condensation reaction between the above-mentioned aldehyde compound and phosphonic acid is carried out by Wittig-Horner-Emm.
This reaction is known as the ons reaction, and is preferably carried out in the presence of a basic catalyst. In this case, potassium hydroxide, sodium amide, sodium methylate, potassium-t-butoxide, etc. are used as the basic catalyst. As the solvent, methyl alcohol, ethyl alcohol, t-butyl alcohol, toluene, tetrahydrofuran, dioxane, dimethyl sulfoxide, N, N-dimethylformamide and the like are used. The reaction temperature is usually room temperature to 100 ° C. The phosphonate represented by the general formula (6) used as a raw material in the present invention is obtained by directly reacting the corresponding halogen compound and trialkyl phosphite with an organic solvent such as toluene, xylene, N, N-dimethylformamide. It is easily synthesized by reacting with heating in.

In the general formula (1), when Ar ₁ is an aryl group having a substituent, the substituent is a lower alkyl group having 1 to 4 carbon atoms or a lower alkyl group having 1 to 4 carbon atoms. Alkoxy groups, cycloalkyl groups having 5 to 6 carbon atoms, benzyl groups, phenyl groups, halogen atoms and the like,
When the substituent is a lower alkyl group or a lower alkoxy group, it may be further substituted with a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom, and when the substituent is a benzyl group or a phenyl group, it has 1 carbon atom. It may be further substituted with a lower alkyl group having 4 to 4 or a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom. Examples of the aryl group of Ar ₁ include a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group, a phenanthryl group and a pyrenyl group. When Ar ₂ is a phenylene group, a naphthylene group, a biphenylene group or an anthrylene group having a substituent, the substituent may be a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms or halogen. And the like. When the substituent is a lower alkyl group or a lower alkoxy group, it may be further substituted with a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom.

An aryl group in which X, Y or Z has a substituent.
When it is a sulfonyl group, examples of the substituent include the same substituents as described above which Ar ₁ may have. When X is an alkyl group having a substituent, the substituent is a lower alkoxy group having 1 to 4 carbon atoms and 5 to 5 carbon atoms.
6 cycloalkyl groups, halogen atoms and the like. Examples of the aryl group for X, Y or Z include phenyl group, naphthyl group, biphenylyl group, anthryl group and pyrenyl group. When R ₁ is a lower alkyl group or a lower alkoxy group, the lower alkyl group may be a straight chain or branched alkyl group having 1 to 4 carbon atoms, and the lower alkoxy group may be a straight chain having 1 to 4 carbon atoms. Alternatively, a branched alkoxy group may be mentioned.

Preferred specific examples of the compound according to the present invention which can be used as the charge transport agent include the following.

Compound No. 1

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Compound No. 2

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Compound No. 3

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Compound No. 4

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Compound No. 5

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Compound No. 6

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Compound No. 7

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Compound No. 8

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Compound No. 9

[Chemical 21]

Compound No. 10

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Compound No. 11

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Compound No. 12

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Compound No. 13

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Compound No. 14

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Compound No. Fifteen

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Compound No. 16

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Compound No. 17

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Compound No. 18

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Compound No. 19

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Compound No. 20

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The electrophotographic photosensitive member of the present invention comprises the above-mentioned 9,
It has a photosensitive layer containing one or more 9-dimethylxanthene compounds. There are various forms of the photosensitive layer, and any of them may be used as the photosensitive layer of the electrophotographic photosensitive member of the present invention. As a typical example, the photoreceptor is shown in FIGS.

The photosensitive member shown in FIG.
A photosensitive layer 2 comprising a 9-dimethylxanthene compound, a sensitizing dye and a binder resin is provided. The photosensitive member of FIG. 2 has a photosensitive layer 21 in which a charge generating substance 4 is dispersed in a charge transport medium 3 composed of a 9,9-dimethylxanthene compound and a binder resin on a conductive support 1. is there.
In the present photoreceptor, the charge generation substance absorbs light to generate charge carriers, which are transported by the charge transport medium. In this case, it is desirable that the charge transporting material is transparent to light that generates charge carriers. The 9,9-dimethylxanthene compound satisfies the condition that the absorption wavelength range does not overlap with the charge generating substance, with only a slight absorption in the low wavelength range from the ultraviolet to the visible region.

The photoreceptor shown in FIG. 3 is formed by laminating a charge generation layer 5 mainly composed of a charge generation substance 4 on a conductive support 1 and a charge transport layer 3 composed of a 9,9-dimethylxanthene compound and a binder resin. The photosensitive layer 22 is formed. In the present photoreceptor, light transmitted through the charge transport layer 3 reaches the charge generation layer 5 and is absorbed by the charge generation substance 4 to generate charge carriers.
The charge carriers are injected into the charge transport layer 3 and transported. The photosensitive member of FIG. 4 is provided with a photosensitive layer 23 in which the order of stacking the charge generation layer 5 and the charge transport layer 3 of the photosensitive member of FIG. 3 is reversed. Generation and transport of charge carriers can be explained by the same mechanism as described above. The photosensitive member of FIG. 5 has a photosensitive layer 24 in which a protective layer 6 is further laminated on the charge generation layer 5 of the photosensitive member of FIG. 4 for the purpose of improving mechanical strength.

The photoconductor of the present invention as exemplified above is manufactured by a conventional method. For example, the above general formula (1)
The 9,9-dimethylxanthene compound represented by the following is dissolved in a suitable solvent together with a binder resin, and if necessary, a charge generating substance, a sensitizing dye, an electron-withdrawing compound or a plasticizer,
It can be produced by coating a coating solution prepared by adding a pigment and other additives on a conductive support and drying it to form a photosensitive layer of several μm to several tens of μm. In the case of a photosensitive layer composed of two layers of a charge generation layer and a charge transport layer, the above-mentioned coating solution is applied onto the charge generation layer, or the charge generation layer is applied onto the charge transport layer obtained by applying the above-mentioned coating solution. It can be manufactured by forming. Further, the photoreceptor thus manufactured may be provided with an adhesive layer, an intermediate layer, and a barrier layer, if necessary.

Solvents for preparing the coating solution include tetrahydrofuran, 1,4-dioxane, methyl ethyl ketone,
Examples thereof include polar organic solvents such as cyclohexanone, acetonitrile, N, N-dimethylformamide and ethyl acetate, aromatic organic solvents such as toluene and xylene, and chlorinated hydrocarbon solvents such as dichloromethane and dichloroethane. A solvent having a high solubility in the 9,9-dimethylxanthene compound and the binder resin is preferably used.

Examples of the sensitizing dyes include triarylmethane dyes such as methyl violet, brilliant green, crystal violet and acid violet, xanthene dyes such as rhodamine B, eosin S and rose bengal, and thiazine dyes such as methylene blue. Examples thereof include pyrylium dyes such as benzopyrylium salts, thiapyrylium dyes, and cyanine dyes.

Examples of the electron-withdrawing compound which forms a charge transfer complex with a 9,9-dimethylxanthene compound include chloranil, 2,3-dichloro-1,4-naphthoquinone, 1-nitroanthraquinone and 2-chloroanthraquinone. , Quinones such as phenanthrenequinone, aldehydes such as 4-nitrobenzaldehyde, 9-benzoylanthracene, indandione, 3,5-dinitrobenzophenone, 2,4,7-trinitrofluorenone,
Ketones such as 2,4,5,7-tetranitrofluorenone, phthalic anhydride, acid anhydrides such as 4-chloronaphthalic anhydride, tetracyanoethylene, terephthalalmalenonitrile, 9-anthrylmethylidene maleno Examples thereof include cyano compounds such as nitrile, 3-benzalphthalide, and phthalides such as 3- (α-cyano-p-nitrobenzal) -4,5,6,7-tetrachlorophthalide.

Examples of the binder resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester and butadiene, polyvinyl acetal, polycarbonate, polyester, polyphenylene oxide, polyurethane, Various resins that are compatible with the 9,9-dimethylxanthene compound, such as cellulose ester, phenoxy resin, silicon resin, and epoxy resin, can be mentioned. The amount of the binder resin used is usually 0.4 to 10 times by weight, preferably 0.5 to 5 times by weight, the amount of the 9,9-dimethylxanthene compound.

Further, the photosensitive layer of the present invention may contain a well-known plasticizer for the purpose of improving film-forming property, flexibility and mechanical strength. Examples of the plasticizer include phthalic acid ester, phosphoric acid ester, chlorinated paraffin, methylnaphthalene, epoxy compound, chlorinated fatty acid ester and the like.

Further, as the electroconductive support on which the photosensitive layer is formed, the materials used in the well-known electrophotographic photoreceptors can be used. For example, a metal drum such as aluminum, stainless steel or copper, a sheet or a laminate of these metals, a vapor deposition product, a metal powder, carbon black, copper iodide or a conductive substance such as a polymer electrolyte is applied together with an appropriate binder. Conductive treated plastic film,
Examples thereof include a plastic drum, paper, a paper tube, and a plastic film and a plastic drum which are made conductive by containing a conductive substance.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples. Parts in Examples are parts by weight.

Synthesis Example 1 (Synthesis of Compound No. 1) "Synthesis of 2- [N- (4-formylphenyl) -N-phenylamino] -9,9-dimethylxanthene" 2-
22.4 g (0.06 mol) of (N, N-diphenylamino) -9,9-dimethylxanthene was dissolved in 100 ml of N, N-dimethylformamide, and 13.6 g (0.09 mol) of phosphorus oxychloride was added at room temperature. It dripped over 30 minutes. It heated up to 50 degreeC and stirred for 3 hours. After completion of the reaction, 25 g (0.58 mol) of 93% sodium hydroxide
Was dissolved in 500 ml of water, and the reaction solution was added and stirred. After further adding 300 ml of toluene to extract the desired product, it was washed with water and concentrated to give 2 [N- (4-formylphenyl) -N-phenylamino] -9,9-dimethylxanthene (20.5 g, yield: 84. 1%) was obtained.

"Synthesis of 2- {N- [4- (4-methylstyryl) phenyl] -N-phenylamino} -9,9-dimethylxanthene" 2- [N- (4
-Formylphenyl) -N-phenylamino] -9,9
-Dimethylxanthene 10.2 g (0.025 mol)
And diethyl p-methylbenzylphosphonate 7.3 g
(0.03 mol) of N, N-dimethylformamide 6
After dissolving in 0 ml, 3.7 g (0.033 mol) of potassium-t-butoxide was added over 30 minutes at room temperature. After the addition, stirring was continued for 2 hours. After confirming the disappearance of the formyl compound, the reaction was terminated. Reaction at 5 ° C
The crystals were poured into 300 ml of methanol below, 30 ml of water was added dropwise, and the precipitated crystals were filtered, washed with methanol and washed with water, and dried. This crystal was subjected to column chromatography (carrier; silica gel, eluent; toluene: hexane =
1: 3) to give 2- {N- [4- (4-methylstyryl) phenyl] -N-phenylamino} -9,9
-Dimethylxanthene (Compound No. 1) 9.4 g (yield; 76.2%, melting point; 131.0-132.0 ° C) was obtained. Elemental analysis values were as shown below as C ₃₆ H ₃₁ NO. Carbon: 87.63% (87.59%), Hydrogen:
6.13% (6.33%), nitrogen: 2.95% (2.8)
4%) (calculated values are shown in parentheses.) Infrared absorption spectrum (KBr tablet method) characteristic fundamental wave number (c
m ^-1 ) is 3024, 2962, 1591, 1478, ¹
It was 243, 752 and so on.

Synthesis Example 2 (Synthesis of Compound No. 6) "2- {N- [4- (2,2-diphenylvinyl) phenyl] -N-phenylamino} -9,9-dimethylxanthene (Compound No. Synthesis of 6) ”2- [N- (4-formylphenyl) -N-phenylamino] -9,9-dimethylxanthene 10.2 g (0.
(025 mol) and diethyl diphenylmethylphosphonate (9.2 g, 0.03 mol) were dissolved in N, N-dimethylformamide (60 ml), and potassium-t-butoxide (3.7 g, 0.033 mol) was added thereto at room temperature over 30 minutes. . After the addition, stirring was continued for 2 hours. After confirming the disappearance of the formyl compound, the reaction was terminated. The reaction product was poured into 300 ml of methanol at 5 ° C or lower, and further 30 m of water.
l was added dropwise, and the precipitated crystals were filtered, washed with methanol and water, and dried. The crystals were purified by column chromatography (carrier; silica gel, eluent; toluene: hexane = 1: 3) to give 2- {N- [4- (2,2
-Diphenylvinyl) phenyl] -N-phenylamino} -9,9-dimethylxanthene (Compound No. 6)
9.5 g (yield; 68.4%, melting point; 215.5-21
7.0 ° C.) was obtained. Elemental analysis values were as shown below as C ₄₁ H ₃₃ NO. Carbon: 88.51% (88.61
%), Hydrogen: 5.87% (5.99%), nitrogen: 2.6
5% (2.52%) (calculated value is shown in parentheses.) Characteristic fundamental wave number (c) of infrared absorption spectrum (KBr tablet method)
m ⁻¹ ) is 3022, 2962, 1588, 1479, ¹
It was 306, 759 and so on.

Example 1 As a charge generating agent, the following chlorodian blue (charge generating agent No. 1)

[0060]

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1.5 parts of polyester resin (Byron 2
00, Toyobo Co., Ltd.) 8 wt% THF solution 18.5
In addition to the parts, the mixture was placed in an agate pot containing agate balls, and rotated by a planetary type fine pulverizer (made by Fritz Co.) for 1 hour to disperse. The resulting dispersion is deposited on an aluminum deposited P as a conductive support.
It was applied on an aluminum surface of the ET film using a wire bar and dried at 60 ° C. under normal pressure for 2 hours and further under reduced pressure for 2 hours to form a charge generation layer having a thickness of 0.3 μm. On the other hand, Compound No. 1.5 parts of the 9,9-dimethylxanthene compound of 1 was added to 18.75 parts of an 8 wt% dichloroethane solution of a polycarbonate resin (Panlite K-1300, manufactured by Teijin Kasei Co., Ltd.), and ultrasonic waves were applied to add 9,9
-The dimethylxanthene compound was completely dissolved. This solution was applied onto the charge generation layer with a wire bar and dried under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours to form a charge transport layer having a film thickness of 20 μm. 1
Was prepared. About this photoconductor Electrostatic copying paper tester (trade name "EPA-8100" Kawaguchi Electric Co., Ltd.)
(Manufactured by K.K.) was used to measure the sensitivity. First, place the photoconductor in the dark-
It is charged by a corona discharge of 6 kV and then exposed to white light of 3.0 lux, and the time (seconds) until the surface potential decreases to half of the initial surface potential is measured.
/ 2 (look seconds) was calculated. The initial surface potential of this photosensitive member was −861 V, and E1 / 2 was 0.92 lux · second.

Examples 2 to 12 The charge generating agent and charge transporting agent (9, 9) used in Example 1 were used.
-Dimethylxanthene compound) was replaced with the one shown in Table 1, and in the same manner as in Example 1, the photoreceptor No. 2-12
Was prepared.

[0063]

[Table 1]

The charge generating agent Nos. Shown in Table 1 were used. Two
No. The structure of 4 is shown below.

Charge generating agent No. 2

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Charge Generating Agent No. 3

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Charge Generating Agent No. 4

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Photoreceptor No. Sensitivity was measured for 2 to 12 in the same manner as in Example 1. Table 2 shows the results.

[0069]

[Table 2]

Example 13 The charge transfer agent (9,9-dimethylxanthene compound) used in Example 1 was replaced with compound No. No. 1, 9,9-dimethylxanthene compound and compound No. Photoreceptor No. 6 was carried out in the same manner as in Example 1 except that the mixture of the 9,9-dimethylxanthene compound of Example 6 was used in a 1: 1 weight ratio. 13 was produced. When the sensitivity of this photosensitive member was measured in the same manner as in Example 1, the initial surface potential was -846 V and E1 / 2 was 0.88.
Looks seconds.

Example 14 As a charge generating agent, 1.5 parts of α-type titanyl phthalocyanine oxide (α-TiOPc) was added to a polyvinyl butyral resin (S-REC BX-L, Sekisui Chemical Co., Ltd.) in a 3 wt% THF solution of 50 parts. In addition, 45 with ultrasonic disperser
Dispersed for minutes. The obtained dispersion is applied on an aluminum surface of an aluminum-deposited PET film as a conductive support using a wire bar, and dried at 60 ° C. under normal pressure for 2 hours and further under reduced pressure for 2 hours to obtain a film thickness of 0.2 μm. Was formed. On the other hand, Compound No. 1.5 parts of the 9,9-dimethylxanthene compound of 1 was added to 18.75 parts of an 8 wt% dichloroethane solution of a polycarbonate resin (Panlite K-1300, manufactured by Teijin Kasei Co., Ltd.), and ultrasonic waves were applied to add 9,9 -The dimethylxanthene compound was completely dissolved. This solution was applied onto the charge generation layer with a wire bar and dried under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours to form a charge transport layer having a film thickness of 20 μm. 14 was produced. The sensitivity of this photoconductor was measured using an electrostatic copying paper tester (trade name "EPA-8100"). First, the photoconductor is charged in a dark place by corona discharge of −6 kV, and then exposed to a monochromatic light of 800 nm with a light amount of 5.0 μW / cm ² , and the amount of energy until the surface potential is reduced to half of the initial surface potential. Then, the half-exposure dose E1 / 2 (μJ / cm ² ) was measured. The initial surface potential of this photoconductor is -806 V, and E1 / 2 is 0.68 μJ.
/ Cm ² .

Example 15 The procedure of Example 14 was repeated except that X-type metal-free phthalocyanine was used as the charge generating agent in place of α-TiOPc. 15 were created. When the sensitivity of this photosensitive member was measured in the same manner as in Example 14, the initial surface potential was -794 V and E1 / 2 was 0.74 μJ / cm ² . Example 16 As a charge generating agent, the following trisazo compound was used instead of α-TiOPc.

[0073]

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The same procedure as in Example 14 was carried out except that No. 16 were produced. Example 14
When the sensitivity was measured in the same manner as above, the initial surface potential was −1010 V and E1 / 2 was 0.57 μJ / cm ² .

Example 17 The following thiapyrylium salt as a charge generating agent

[0076]

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0.1 part, Compound No.
10 parts of 9,9-dimethylxanthene compound of 3 was added to 125 parts of 8 wt% solution of polycarbonate resin (Panlite K-1300, Teijin Kasei Co., Ltd.) in 8% by weight dichloroethane, and ultrasonic waves were applied to the solution to produce thiapyrylium salt and 9,9. -The dimethylxanthene compound was completely dissolved. This solution is applied on the aluminum surface of an aluminum vapor-deposited PET film which is a conductive support using a wire bar, and dried under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours to form a photosensitive layer having a film thickness of 20 μm. Form the photoconductor No. 17 was produced. About this photoconductor, an electrostatic copying paper tester (trade name "EPA-81"
00 ") was used to measure the sensitivity. First, the photoreceptor is charged by a corona discharge of +7 kV in the dark, and then 3.0
It was exposed to white light having a lux, and the time (seconds) until the surface potential decreased to half of the initial surface potential was measured to obtain a half-exposure amount E1 / 2 (lux seconds). The initial surface potential of this photosensitive member was +945 V, and E1 / 2 was 1.4 lux · sec.

Example 18 The coating solution of the charge transfer agent used in Example 1 was applied to aluminum vapor-deposited PE.
It was applied on the aluminum surface of the T film using a wire bar and dried under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours to form a charge transport layer having a film thickness of 10 μm. On the other hand, the same disazo compound as that used in Example 2 as the charge generating agent 3.
0 part was added to 18.5 parts of an 8 wt% THF solution of a polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.), placed in an agate pot containing agate balls, and a planetary type fine pulverizer (made by Fritz) for 1 hour. Rotated and dispersed. To this dispersion, 200 parts of THF was added, and mixed by stirring to obtain a coating liquid. This coating solution was applied onto the above charge transport layer by spraying and dried under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours to form a charge generation layer having a thickness of 0.5 μm. Further, a solution prepared by dissolving an alcohol-soluble polyamide resin in isopropanol is spray-coated on the charge generation layer, and the film thickness is 0.5 μm under normal pressure at 60 ° C. for 2 hours and further under reduced pressure for 2 hours.
Of the photoconductor No. 18 were produced. The sensitivity of this photoreceptor was measured in the same manner as in Example 17. The initial surface potential of this photoconductor is + 826V,
E1 / 2 was 1.2 lux · sec.

Comparative Example 1 Compound No. used in Example 1 The following compounds instead of the 9,9-dimethylxanthene compound of 1

[0080]

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A comparative photoconductor was prepared in the same manner as in Example 1 except that The sensitivity of this photoreceptor was measured in the same manner as in Example 1. The initial surface potential of this photoconductor is -87.
At 0 V, E1 / 2 was 1.18 lux · sec.

[0082]

INDUSTRIAL APPLICABILITY The novel 9,9-dimethylxanthene compound of the present invention has an excellent charge transporting ability and can be widely used as a charge transporting material. Further, the electrophotographic photoreceptor of the present invention having a photosensitive layer containing these compounds on a conductive support shows excellent photoreceptor characteristics,
It has the advantage that it can be widely used as a photoreceptor for electrophotography.

[0083]

[Brief description of drawings]

FIG. 1 is a sectional view of a single-layer photoconductor for electrophotography.

FIG. 2 is a cross-sectional view of a single-layer photoconductor for electrophotography in which a charge generating substance is dispersed.

FIG. 3 is a cross-sectional view of an electrophotographic photoconductor in which a charge generation layer and a charge transport layer are laminated on a conductive support in this order.

FIG. 4 is a cross-sectional view of an electrophotographic photoconductor in which a charge transport layer and a charge generation layer are laminated in this order on a conductive support.

FIG. 5 is a cross-sectional view of an electrophotographic photoconductor provided with a protective layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2, 21, 22, 23, 24 Photosensitive layer 3 Charge transport medium, charge transport layer 4 Charge generating substance 5 Charge generating layer 6 Protective layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chieko Inayoshi 45 Miyukigaoka, Tsukuba, Ibaraki Hodogaya Chemical Industry Co., Ltd. Tsukuba Research Institute

Claims (2)

[Claims] 1. The following general formula (1): [In the formula, Ar ₁ represents an aryl group which may have a substituent, Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group which may have a substituent, or an anthrylene group, and X represents Represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Y represents an aryl group which may have a substituent or the following general formula (2) 2] Alternatively, the following general formula (3): (In the formula, R ₁ represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, R ₂ represents a hydrogen atom, a halogen atom or a lower alkyl group, and Z represents a hydrogen atom or an optionally substituted substituent. Represents a radical group, and m and n represent an integer of 0 to 4). ] The 9,9- dimethyl xanthene compound represented by these. 2. The following general formula (1): embedded image on a conductive support. [In the formula, Ar ₁ represents an aryl group which may have a substituent, Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group which may have a substituent, or an anthrylene group, and X represents Represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Y represents an aryl group which may have a substituent or the following general formula (2) 5] Alternatively, the following general formula (3): (In the formula, R ₁ represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, R ₂ represents a hydrogen atom, a halogen atom or a lower alkyl group, and Z represents a hydrogen atom or an optionally substituted substituent. Represents a radical group, and m and n represent an integer of 0 to 4). ] It has a photosensitive layer containing the 9,9- dimethylxanthene compound represented by these, The photoreceptor for electrophotography characterized by the above-mentioned.