JPS6159622B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel 9-(4-N,N-dibenzylaminostyryl)anthracene compound and a method for producing the same. Electrophotography, which is known as a method for obtaining copied images, generally involves first charging a photoreceptor in a dark place using means such as corona discharge, and then irradiating it with light to charge only the exposed areas. The content is to form an electrostatic latent image by selectively discharging the liquid, and then to visualize the latent image using a developing means using toner or the like. The photoreceptor used in such electrophotography must have photoconductive properties, specifically (1) being able to be charged to an appropriate potential in the dark; (2) There are basically three requirements: (3) discharge of charge is small in the dark, and (3) discharge of charge is rapid upon irradiation with light. By the way, the photoconductive materials used in manufacturing electrophotographic photoreceptors include inorganic photoconductive materials such as selenium and zinc oxide, and organic photoconductive materials such as poly-N-vinylcarbazole. It is broadly divided into materials. Among the former, selenium in particular is widely used in practical use due to its excellent photoconductive properties; Photoreceptors have the disadvantage of being difficult to apply. On the other hand, although the latter organic photoconductive materials can be easily applied to flexible photoreceptors, there is a problem that the photoconductive properties themselves are not necessarily sufficient. As a result of repeated research aimed at developing an organic photoconductive material with properties superior to conventional products, the present inventors found that
It has been found that a new compound represented by the following general formula () has excellent photoconductive properties and is therefore extremely useful as a photoconductive material for electrophotographic photoreceptors. Therefore, the novel compound according to the present invention has the general formula () (In the formula, R represents a hydrogen atom, a halogen atom, a methyl group, or a nitro group.) 9-(4-N,
The N-dibenzylaminostyryl)anthracene compound is synthesized by reacting a compound represented by the general formula () with a compound represented by the general formula (). (In the formula, R' represents an alkyl group having 1 to 4 carbon atoms, and R represents the same atom or group as above.) That is, dialkyl 9-anthrylmethylphosphonate of general formula () and 4-anthrylmethylphosphonate of general formula ()
9-(4-
A N,N-dibenzylaminostyryl)anthracene compound can be obtained. Furthermore, the general formula ()
Dialkyl 9-anthrylmethylphosphonate can be synthesized by the method described in JP-A-51-98260. The reaction (condensation reaction) between the compound of general formula () and the compound of general formula () is carried out in an organic solvent in the presence of a strong basic compound. The amount of the compound used is usually stoichiometric. As a reaction solvent,
Aromatic solvents such as benzene, toluene, xylene, chlorobenzene, methanol, ethanol,
Alcohol solvents such as isopropanol, butanol, 2-methoxyethanol, bis(2-methoxyethyl) ether, tetrahydrofuran,
In addition to ether solvents such as dioxysan, dimethyl sulfoxide, dimethyl formamide, N
-Methylpyrrolidone and the like can be used, among which polar solvents exemplified by dimethylformamide and dimethylsulfoxide are particularly suitable as the reaction solvent of the present invention. The strong basic compound functions as a condensing agent, and for this, alkali metal hydroxides, alkali metal alcoholates (preferably _C1 to _C4 ), and even amides can be used. For economical reasons, the use of alkali metal hydroxides or alcoholates is recommended. The amount of the strong basic compound used depends on the reaction temperature, but generally per mole of dialkyl 9-anthrylmethylphosphonate of the general formula (),
The amount is 1 to 5 mol, preferably 1 to 3 mol. The reaction temperature is within the range of 10-180°C. However, depending on the type of reactant to be subjected to the condensation reaction, the strong basic compound used, and the type of reaction solvent, it is possible to select the reaction temperature within the above range, especially depending on the type of reaction solvent. For example, when using a polar solvent, 10-100℃, preferably 20-100℃
The reaction temperature is usually set at 60°C. However, even in such a case, if the activity of the strong basic compound serving as the condensing agent is relatively weak, or if shortening of the reaction time is required, a higher reaction temperature (up to 180°C) can of course be used. . As mentioned above, 9-(4-N,N
-Dibenzylaminostyryl) anthracene compounds are extremely useful as photoconductive materials in electrophotographic photoreceptors, and when used in this purpose, they can be used in combination with dyes or sensitizers such as Lewis acids. Compounds can be optically or chemically sensitized. Examples of such sensitizers include triallylmethane dyes such as methyl violet and crystal violet, xanthene dyes such as rose bengal, erythrosine, and rhodamine B, thiazine dyes such as methylene blue, and 2,4,7-trinitro-9- Fluorenone, 2,4-dinitro-
Examples include 9-fluorenone. Furthermore, when the novel compound of the present invention is used as a photoconductive material, it can be used in combination with an appropriate organic pigment, such as C.I. Pigment Blue (CI No. 21180), C.I. Pigment Red 41 ( CI
No. 21200), CI Basic Cred 3 (CI No.
Azo pigments such as CI Pigment Blue 16 (CI No. 74100), phthalocyanine pigments such as CI Pigment Blue 16 (CI No. 74100), and CI Bat Brown 5 (CI No. 74100).
Favorable results can be obtained by using it in combination with indigo pigments such as CI Butto Dye (CI No. 73410) and CI Butto Dye (CI No. 73030), and perylene pigments such as Argo Scarlet B and Indance Scarlet R. Furthermore, in some cases, it is also possible to use inorganic pigments such as selenium, selenium-tellurium, and cadmium sulfide. Next, the effects of using the 9-(4-N,N-dibenzylaminostyryl)anthracene compound of the present invention as a photoconductive material for an electrophotographic photoreceptor will be explained. All terms mean "parts by weight." CI Pigment Blue 25 (CINo.21180) 2
98 parts of tetrahydrofuran is added to the mixture, and the mixture is ground and mixed in a ball mill to obtain a pigment dispersion. This dispersion was applied onto a polyester film coated with aluminum using a doctor blade, and air-dried to form a pigment layer with a thickness of 1 μm. Next, 2 parts of the compound 9-(4-N,N-dibenzylaminostyryl)anthracene of the present invention, 3 parts of polycarbonate (Teijin Panlite L) and 45 parts of tetrahydrofuran were mixed to prepare a solution, which was added as above. The pigment layer was coated using a doctor blade and dried at 100° C. for 10 minutes to form a layer with a thickness of 9 μm to obtain an electrophotographic photoreceptor. This photoreceptor was negatively charged by applying -6KV corona discharge for 20 seconds using an electrostatic copying paper tester, and then left in a dark place for 20 seconds.
The surface potential Vpo (volts) at that time is measured, and then the surface illuminance of the photoreceptor is adjusted using a tungsten lamp.
Light irradiation was carried out under conditions such that the light was 20 lux,
The time (seconds) required for the surface potential of the photoreceptor to become 1/2 of Vpo was determined, and the half-reduced exposure amount E1/2 (lux seconds) was calculated. The results showed Vpo = 1200 volts and E1/2 = 2.5 lux-seconds, which are extremely sensitive values. Next, specific examples of the present invention will be explained with reference to Examples. Example 1 4.7 g of potassium t-butoxide was added to 70 ml of N,N-dimethylformamide (hereinafter abbreviated as DMF)
and stirred thoroughly at room temperature to obtain a dispersion. 6.9 g of diethyl 9-anthrylmethylphosphonate was added to this dispersion, and then 4-N,N-
7.0g of dibenzylaminobenzaldehyde
A solution dissolved in 20 ml of DMF was gradually added dropwise while being careful not to let the reaction temperature exceed 40°C. After the addition was completed, the mixture was stirred at room temperature for 4 hours, then neutralized by adding acetic acid while cooling with ice water, and further diluted with about 50 ml of water. The resulting crystals were filtered, washed with water, and dried to obtain the product. Ta. Yield 9.2g (yield 92.0%), melting point 191.5~
It was 193.0℃. Next, this product was recrystallized from ethyl acetate to obtain pure 9-(4-N,N-dibenzylaminostyryl)anthracene in the form of yellow needle crystals with a melting point of 193.0-194.0°C. Elemental analysis value C% H% N% Actual value 90.85 6.17 2.94 Calculated value as C ₃₆ H ₂₉ N 90.90 6.16 2.95 Infrared absorption spectrum (KBr tablet method) δt- (CH=CH-) 955cm ^-1 (See attached drawing) Examples 2 to 6 Instead of 4-N,N-dibenzylaminobenzaldehyde in Example 1, the aldehydes shown in the following table were used as raw materials, and the respective raw material aldehydes and diethyl 9-anthrylmethylphosphonate were changed as shown in the following table. A novel anthracene compound of the present invention was obtained by reacting using the reaction solvent, reaction temperature, and strong basic compound shown. The reaction yield, melting point, elemental analysis value, and infrared absorption characteristics of the anthracene compound produced are also listed in the following table. In addition, substituted benzyl group

When [Formula] is represented by [A], the raw material aldehyde and the produced anthracene compound of Examples 2 to 6 are respectively

[Formula] and

[Formula]] Therefore, in the following table, only the substituted benzyl group of the raw material aldehyde is shown, and the structural formulas of the raw material aldehyde and the produced anthracene compound are omitted.

【table】 [Brief explanation of the drawing]

The attached drawings show the 9-(4-
The infrared absorption spectrum of N,N-dibenzylaminostyryl)anthracene is shown.

Claims (1)

[Claims] 1 General formula () (In the formula, R represents a hydrogen atom, a halogen atom, a methyl group, or a nitro group.) A 9-(4-N,N-dibenzylaminostyryl)anthracene compound represented by the following. 2 General formula () (In the formula, R' represents an alkyl group having 1 to 4 carbon atoms.) A dialkyl 9-anthrylmethylphosphonate represented by the general formula () (In the formula, R represents a hydrogen atom, a halogen atom, a methyl group, or a nitro group.) Reacting with 4-N,N-dibenzylaminobenzaldehyde in the presence of a strong basic compound in an organic solvent. A general formula consisting of (In the formula, R represents the same atom or group as above.) A method for producing a 9-(4-N,N-dibenzylaminostyryl)anthracene compound represented by the following.