JPH04330051A - Vinylene compound and photosensitizer using the same - Google Patents

Abstract

PURPOSE:To provide a novel vinylene compound having an excellent charge- transferring ability, high charge transfer degree compared with known charge transfer materials and excellent sensitivity, and capable of supplying photosensitizers having high repeating characteristics. CONSTITUTION:A compound of formula I (R1-R<6> are H, or alkyl, aryl, aralkyl or heterocyclic group which may have a substituent), e.g. a compound of formula II. The compound of formula I is obtained by reacting a compound of formula III with a compound of formula IV (X is halogen) in a boiling solvent. A single layer type photosensitizing layer comprising a charge generating material, the compound of formula I as a charge transfer material, and a binding resin, or a lamination type photosensitizing layer comprising a charge-generating layer and a charge transfer layer is disposed on a conductive substrate to provide a photosensitizer having an excellent photosensitizing ability and a high repeating characteristic.

Description

Description: [0001] The present invention relates to a novel vinylene compound and a photoreceptor using the same. [0002] In recent years, organic photoreceptors have been widely used as photoreceptors in image forming devices such as copying machines, printers, facsimile machines, etc. due to their excellent processability and economic efficiency, and their great flexibility in functional design. . Further, when forming a copy image using a photoreceptor, the Carlson process is widely used. The Carlson process consists of a charging process in which a photoreceptor is uniformly charged by corona discharge, an exposure process in which an original image is exposed to the charged photoreceptor to form an electrostatic latent image corresponding to the original image, and an electrostatic latent image is transferred to a toner. A development process in which a toner image is formed by developing with a developer containing , and a cleaning step of removing toner remaining on the photoreceptor. In this Carlson process, in order to form a high-quality image, the photoreceptor is required to have excellent charging characteristics and photosensitivity characteristics, and to have a low residual potential after exposure. Inorganic photoconductors such as selenium and cadmium sulfide have heretofore been known as photoreceptor materials, but these have the drawbacks of being toxic and having high production costs. Therefore, so-called organic photoreceptors using various organic substances in place of these inorganic substances have been proposed. Such an organic photoreceptor has a photosensitive layer made of a charge-generating material that generates charges upon exposure to light, and a charge-transporting material that has a function of transporting the generated charges. [0004] In order to satisfy various conditions desired for such an organic photoreceptor, it is necessary to appropriately select the charge generating material and the charge transporting material. Various organic compounds have been proposed as charge transport materials, and for example, hydrazone compounds are known. [0005] However, conventional charge transport materials have a problem in that they do not have sufficient sensitivity or repeatability. An object of the present invention is to solve such technical problems and to provide a vinylene compound having high sensitivity and excellent repeatability, and a photoreceptor for electrophotography using the vinylene compound. Means for Solving the Problems and Effects To achieve the above object, the vinylene compound of the present invention has the general formula (
1): [Formula 3] (wherein, R1 , R2 , R3 , R4
, R5 and R6 are the same or different and are a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted aralkyl group, or a substituted Indicates a heterocyclic group which may have a group. ). The vinylene compound of the present invention has excellent charge transport ability and higher charge mobility than conventional charge transport materials such as hydrazone compounds. The photoreceptor of the present invention is characterized in that a photosensitive layer containing a vinylene compound represented by the above general formula (1) is provided on a conductive substrate, whereby the photoreceptor of the present invention has an improved sensitivity. Excellent,
Has high repeatability. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group,
Examples include straight-chain or branched alkyl groups having 1 to 6 carbon atoms such as isobutyl group, t-butyl group, pentyl group, and hexyl group. Examples of the aralkyl group include benzyl group, α-phenethyl group, β-phenethyl group, 3-phenylpropyl group, benzhydryl group, and trityl group. Examples of the heterocyclic group include thienyl group, pyrrolyl group, pyrrolidinyl group, oxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, 2H-imidazolyl group, pyrazolyl group, triazolyl group, tetrazolyl group, pyranyl group, and pyridyl group. , piperidyl group, piperidino group, 3-morpholinyl group, monophorino group, etc. Examples of the aryl group include phenyl group,
Examples include naphthyl group, biphenyl group, anthryl group, and phenanthryl group. In addition, examples of the substituents on the alkyl group, aralkyl group, heterocyclic group, and aryl group include the alkyl group described above; halogen atoms such as fluorine, chlorine, bromine, and iodine; the aryl group described above; the aralkyl group described above; Heterocyclic group; vinyl, allyl, crotyl, 2-pentenyl, 3-pentenyl, 2-hexenyl,
Examples include alkenyl groups having 2 to 6 carbon atoms such as 1-methylallyl and 1,1-dimethylallyl. Specific examples of the vinylene compound represented by the general formula (1) include the following formula (11):
Examples include those represented by (18). ##STR4## The compound represented by the general formula (1) is:
For example, it can be produced using the following reaction formula (I) or (II). Reaction formula (I): [0017] [0018] (In the formula, R1, R3 and R4 are the same as above, and X represents a halogen atom.) Reaction formula (II)
: [0019] [0020] (wherein R1 , R2 , R3 , R4
, R5, R6 and X are the same as above. ) The above reaction formula (I) is a combination of a compound represented by the general formula (a) and the general formula (
b) by reacting with the sulfide represented by the general formula (1-
a) The compound of the present invention represented by the following is obtained. This reaction can be carried out by boiling the above two compounds in a solvent. Examples of solvents include methanol,
Ethanol, propanol, etc. can be used. [0021] The above reaction formula (II) also has the general formula (a
By reacting the compound represented by 1) and the compound represented by general formula (b1) in the same manner as in reaction formula (I), the compound of the present invention represented by general formula (1-b) can be obtained. It's something you get. The photosensitive layer in the present invention has the general formula (1
) Contains one or more compounds represented by: The photosensitive layer in the present invention includes a single layer type in which a charge generating material, a charge transporting material, which is a compound represented by the general formula (1), and a binder resin are mixed, and a charge generating layer and a charge transporting layer. There is a laminated type in which the photoreceptor of the present invention is laminated, and the photoreceptor of the present invention can be applied to either type. In order to obtain a laminated type photosensitive layer, a charge generation layer containing a charge generation material is formed on a conductive base material, and a charge transport material, which is a compound represented by the above general formula, is formed on this charge generation layer. What is necessary is just to form a charge transport layer containing the above. Furthermore, the stacking order may be reversed and the charge generation layer may be provided on the charge transport layer. As charge generating materials, conventionally used selenium, selenium-tellurium, selenium-arsenic, amorphous silicon, pyrylium salts, azo compounds, disazo compounds, phthalocyanine compounds, anthanthrone compounds, and perylene compounds are used. compounds, indigo-based compounds, triphenylmethane-based compounds, threne-based compounds, toluidine-based compounds, pyrazoline-based compounds, perylene-based compounds, quinacridone-based compounds, pyrrolopyrrole-based compounds, and the like. These charge generating materials can be used alone or in combination of two or more. [0024] Furthermore, the charge transport material having the general formula (1)
The vinylene compound represented by ) can be used in combination with other conventionally known charge transport materials. Conventionally known charge transport materials include, for example, 2,5-di(4-
oxadiazole compounds such as methylaminophenyl)-1,3,4-oxadiazole, styryl compounds such as 9-(4-diethylaminostyryl)anthracene, carbazole compounds such as polyvinylcarbazole,
Pyrazoline compounds such as 1-phenyl-3-(p-dimethylaminophenyl)pyrazole, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds Examples include nitrogen-containing cyclic compounds such as , pyrazole compounds, and triazole compounds, and fused polycyclic compounds. Note that a binder resin is not necessarily required when a charge transporting material having film-forming properties such as polyvinylcarbazole is used. Various resins can be used as the binder resin, such as styrene polymers, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, and acrylic copolymers. Union,
Styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, polycarbonate, polyarylate , thermoplastic resins such as polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, silicone resin, epoxy resin, and other crosslinkable thermosetting resins, as well as photosensitive resins such as epoxy acrylate and urethane-acrylate. Examples include curable resins. These binder resins can be used alone or in combination of two or more. [0026] Examples of the solvent for dissolving the charge generating material, charge transporting material and binder resin to prepare a coating solution include methanol, ethanol, isopropanol,
Alcohols such as butanol, aliphatic hydrocarbons such as n-hexane, octane, and cyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride, and chlorobenzene, and dimethyl ether. , ethers such as diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethyl formaldehyde, dimethyl formamide, and dimethyl sulfoxide. These solvents can be used alone or in combination of two or more. Further, in order to improve the sensitivity of the charge generation layer, a known sensitizer such as terphenyl, halonaphthoquinones, acenaphthylene, etc. may be used together with the charge generation material. Furthermore, a surfactant, a leveling agent, etc. may be used to improve the dispersibility, dyeability, etc. of the charge transport material and charge generation material. Examples of the conductive substrate include aluminum, copper, tin, platinum, silver, vanadium, molybdenum,
Chromium, cadmium, titanium, nickel, palladium,
Single metals such as indium, stainless steel, and brass, and plastic materials on which the above metals are vapor-deposited or laminated;
Examples include glass coated with aluminum iodide, tin oxide, indium oxide, and the like. The conductive substrate may be in the form of a sheet or a drum, as long as the substrate itself is conductive or the surface of the substrate is conductive. Also,
The substrate preferably has sufficient mechanical strength during use. In the laminated photosensitive layer, the charge generation material and the binder resin constituting the charge generation layer can be used in various ratios, but the charge generation material and the binder resin can be used in various ratios. 5 to 500 parts of generated material, especially 10
Preferably, it is used in a proportion of ˜250 parts. [0030] The charge generation layer may have an appropriate thickness, but it may have a thickness of 0.01 to 5 μm, particularly 0.1 to 3 μm.
It is preferable that it be formed to about m. The compound represented by the above general formula (1) (charge transport material) constituting the charge transport layer and the binder resin can be used in various ratios; It is preferable to use the compound represented by the above general formula (1) in an amount of 10 to 500 parts, particularly 25 to 200 parts, based on 100 parts of the binder resin so that it can be easily transported. The charge transport layer is preferably formed to have a thickness of about 2 to 100 μm, particularly about 5 to 30 μm. In a single-layer type photosensitive layer, the charge generating material is 2 to 20 parts, particularly 3 to 15 parts, and the compound represented by the above general formula (charge transporting material) is 40 to 200 parts per 100 parts of the binder resin. ,
In particular, 50 to 150 parts is suitable. In addition, the thickness of the single-layer type photosensitive layer is 10 to 50 μm, especially 15 to 3 μm.
It is preferable that the thickness is about 0 μm. When a photoreceptor including a charge generation layer and a charge transport layer is formed by a coating method, the charge generation material or the charge transport material and the binder resin are coated by a conventionally known method such as a roll mill, a ball mill, an attritor, or a binder resin. Prepare the coating solution using a paint shaker, ultrasonic disperser, etc. [Examples] The present invention will be explained in detail below with reference to Examples and Comparative Examples. Example 1 <Synthesis of the compound represented by the above formula (11)> The following formula (3
13.9 g of the compound represented by 1) and 14.4 g of the compound represented by the following formula (32) were boiled in ethanol for 24 hours to obtain 11.4 g of the title compound. The yield was 48%. Elemental analysis value: Calculated value (%) as C16H14S C80.63 H5.92
S13.45 Actual value (%) C82.22
H5.35 S --- [Chemical formula 8] Example 2 <Compound represented by the above formula (12)> Instead of the compound represented by the formula (31), a compound represented by the formula (33) was used. Compound 15 represented
．． 14.6 g of the title compound was obtained in the same manner as in Example 1, except that 3 g was used. The yield was 55%. Elemental analysis value: Calculated value (%) as C18H18S C81.16 H6.81
S12.03 Actual location (%) C84.12 H
6.30 S --- ##STR9## Each compound was produced in the same manner as in Example 1 using appropriate starting materials. The obtained compounds are as follows. Example 3 <Compound represented by the above formula (13)> Elemental analysis value: Calculated value (%) as C20H24S C81.581 H7.531
S10.888 Actual value (%) C80.21
1 H6.222 S --- Example 4 <Compound represented by the above formula (14)> Elemental analysis value: Calculated value as C18H18S (%) C81.155 H6.811
S12.034 Actual value (%) C79.00
1 H5.321 S --- Example 5 <Compound represented by the above formula (15)> Elemental analysis value: Calculated value (%) as C25H24S C84.222 H6.786
S8.992 Actual value (%) C80.1
20 H7.566 S --- Example 6 <Compound represented by the above formula (16)> Elemental analysis value: Calculated value (%) as C18H18S C81.155 H6.811
S12.034 Actual value (%) C78.31
2 H7.357 S --- Example 7 <Compound represented by the above formula (17)> Elemental analysis value: Calculated value (%) as C20H24S C81.581 H7.531
S10.888 Actual value (%) C78.23
1 H6.931 S --- Example 8 <Compound represented by the above formula (18)> Elemental analysis value: Calculated value (%) as C24H24S C81.581 H7.531
S10.888 Actual value (%) C78.23
1 H6.931 S --- Examples 9-1
4 and Comparative Examples 1 to 3 (laminated photosensitive layer) following formula (A)
, (B) or (C) 2 parts of the charge generating material shown in Table 1, 1 part of polyvinyl butyral resin, and 120 parts of tetrahydrofuran were dispersed for 2 hours in a paint shaker using zirconia beads. I let it happen. The resulting dispersion was applied onto an aluminum sheet using a wire bar and dried at 100°C for 1 hour to give a thickness of 0.
A charge generation layer of 5 μm was obtained. [0038] On this charge generation layer, 1 part of the charge transport material shown in Table 1 and 1 part of polycarbonate resin were added among the compounds obtained in Examples 1 to 8 above and the compounds of the following formulas (21) to (22). was dissolved in 9 parts of toluene and coated with a wire bar, dried at 100°C for 1 hour, and coated with a thickness of 22 μm.
A charge transport layer was obtained. [Chemical 10] [Chemical 11] Examples 15 to 20 and Comparative Examples 4 to 6 (single layer type photosensitive layer) Represented by the above formula (A), (B) or (C) Among the compounds shown in Table 2, 1 part of the charge generating agent shown in Table 2 and 60 parts of tetrahydrofuran were dispersed for 2 hours in a paint shaker using zirconia beads. To the obtained dispersion, 50 parts of a dichloromethane solution of a polycarbonate resin having a solid content of 20% by weight and the compounds obtained in Examples 1 to 8 above and the compounds of formulas (21) to (22) shown in Table 2 were added. Ten parts of the indicated charge transport material were added and dispersion continued for an additional hour. The resulting dispersion was applied onto an aluminum sheet using a wire bar and dried at 100° C. for 1 hour to obtain a photosensitive layer with a thickness of 20 μm. (Evaluation Test) The photoreceptors obtained in Examples 9 to 20 and Comparative Examples 1 to 6 were charged, and their surface potential and residual potential were measured using an evaluation tester ("EPA810" manufactured by Kawaguchi Electric Co., Ltd.).
0''). In addition, the surface potential and residual potential of each of the above-mentioned photoreceptors were measured after repeated charging, exposure, and static elimination for 30 minutes, and the repetition characteristics were evaluated. The measurement conditions are as follows. Light intensity: 50 lux Exposure time: 1/15 seconds Surface potential: Charging was performed by adjusting the inflow current value so that it was around (±)700V. Light source: Tungsten lamp Static elimination: 200 lux Residual potential measurement: Measurement was started 0.2 seconds after the start of exposure. Table 1 shows the results of tests using the photoreceptors of Examples 9 to 14 and Comparative Examples 1 to 3.
Table 2 shows the results of the tests using photoreceptors No. 6 and 6. [Table 1] [Table 2] [0047] From these test results, it can be seen that the photoreceptors of each example had almost no difference in initial surface potential from the conventional photoreceptor (comparative example). , it can be seen that the residual potential is low and the sensitivity is significantly improved. In addition, compared to the conventional photoreceptor (comparative example), the photoreceptor of each example showed less decrease in surface potential after 30 minutes of repeated charging, exposure, and charge removal, and the residual potential was also lower, so the repeatability was improved. You can see that it has been improved. As described above, the vinylene compound of the present invention exhibits high charge transport ability, and the photoreceptor using the vinylene compound of the present invention has excellent sensitivity and repeatability.

Claims (2)

[Claims] Claim 1: General formula (1): [Formula 1] (wherein, R1, R2, R3, R4, R5 and R6 are the same or different and represent a hydrogen atom or an alkyl group which may have a substituent) , an aryl group which may have a substituent, an aralkyl group which may have a substituent, or a heterocyclic group which may have a substituent). 2. A photoreceptor characterized in that a photosensitive layer containing a vinylene compound represented by the following general formula (1) is provided on a conductive substrate. [Formula 2] (wherein R1, R2, R3, R4, R5 and R6 are the same or different, a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent) group, an aralkyl group that may have a substituent, or a heterocyclic group that may have a substituent.)