JPS6160823B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel 9-(4-N,N-dibenzylaminobenzylidene)fluorene compound and a method for producing the same. Conventionally, many materials including poly-N-vinylcarbazole have been proposed as organic photoconductive materials for photoreceptors used in electrophotography. The "electrophotographic method" referred to here generally means that a photoconductive photoreceptor is first charged with a corona discharge in a dark place, and then the electrostatic latent image is formed by selectively discharging the charge only in the exposed areas. This is one of the image forming methods in which an image is formed by visualizing this latent image using a developing means using toner or the like. The basic characteristics required of a photoreceptor in such an electrophotographic method are 1) to be charged to an appropriate potential in a dark place, 2) to have little discharge of charge in a dark place, and 3) to be able to withstand light irradiation. Examples include discharging charges more quickly. However, the reality is that conventional photoconductive organic materials do not necessarily fully satisfy these requirements. On the other hand, selenium and zinc oxide are known as photoconductive inorganic materials, and it is a fact that selenium is widely used in practical applications. However, recently, in terms of the electrophotographic process, various demands have been placed on photoreceptors, including, for example, in addition to the basic characteristics mentioned above.
For example, there is a growing demand for photoreceptors in the form of flexible belts. However, in the case of selenium, it is generally difficult to form it into such a shape. The object of the present invention is to provide a novel 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound which is particularly useful as a photoconductive material, and which eliminates the drawbacks of photoconductive materials for photoreceptors as described above. An object of the present invention is to provide a method for manufacturing the same. That is, one of the present inventions is the general formula () (In the formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group.) A novel 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound .
The 9-(4-N,N-dibenzylaminobenzylidene)fluorene compound represented by the general formula () can be prepared by combining the compound of the general formula () with the general formula () as shown in [Method A] and [Method B] below. Or obtained by reaction with a compound of formula (). (In the above formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group, and R' represents a lower alkyl group having 1 to 4 carbon atoms.) In the above [Method A], the general formula ( ) of 4-N,N
- Dibenzylaminobenzaldehydes and dialkyl 9-fluorenylphosphonate of general formula () are stirred in an organic solvent in the presence of a strongly basic alkali compound at a temperature of 10°C to 180°C for 15 minutes to 3 hours. By carrying out this process, high purity and high yield can be obtained. Dialkyl 9-fluorenylphosphonate of the general formula () can be prepared by the method of BESmith et al. (J.
Am.Chem.Soc, 75 5892 (1955)), and R' is preferably an alkyl group having 4 or less carbon atoms, particularly a methyl group or an ethyl group. Reaction solvents include hydrocarbons such as benzene, toluene, xylene, and thalolbenzene, alcohols and ethers such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, bis(2-methoxyethyl) ether, tetrahydrofuran, and dioxane, and others. ,
dimethyl sulfoxide, dimethyl formamide,
Examples include N-methylpyrrolidone. Among these, polar solvents such as dimethylformamide and dimethylsulfoxide are particularly suitable. The reaction temperature depends on 1) the stability of the solvent used against the reaction components, especially strong alkaline compounds, 2) the reactivity of the condensation components (compounds of general formula and ),
3) The alkaline compound can be selected from a wide range depending on its reactivity as a condensing agent in the solvent. For example, when using polar solvents, it is actually 10
-100°C, preferably 20-60°C. However, when the reaction time is shortened or a less active condensing agent is used, higher temperatures (up to 180°C) may be used. Therefore, in the case of polar solvents, the reaction temperature is basically 10 to 180
℃ range. Strongly basic alkali compounds include hydroxides, amides or alcoholates of alkali metals (preferably alcoholates of alcohols containing 1 to 4 carbon atoms); for economic reasons, lithium,
Preference is given to sodium and potassium hydroxides, amides or alcoholates. The amount of the dialkyl 9-fluorenylphosphonate of the general formula and the aldehyde of the general formula to be used is usually:
It is stoichiometric. The amount of the strongly basic alkali compound to be used varies depending on the above items 2) and 3), but it is usually 1 to 5 times the molar amount, preferably 1 to 5 times the molar amount of the dialkyl 9-fluorenylphosphonate of the general formula. The amount is 1 to 3 times the molar amount. In the above [Method B], 4-N,N- of the general formula ()
Dibenzylaminobenzaldehydes and formula ()
It can be obtained with high purity and high yield by reacting with tri-n-butylphosphonium fluorenylide in an organic solvent at a temperature of 10 to 180°C for 15 minutes to 3 hours. 9-tri-n-butylphosphonium fluorenylide of formula () can be synthesized by the method of AW Johnson et al. (Tetrahedron 9 130 (1960)). Reaction solvents include hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; alcohols and ethers such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, bis(2-methoxyethyl) ether, tetrahydrofuran, and dioxane; Other examples include dimethyl sulfoxide, dimethylformamide, and N-methylpyrrolidone. The reaction temperature can be selected within a wide range depending on the reactivity of the condensation components (compounds of general formula () and formula ()). Usually 10~100℃ preferably
The temperature is 20-80℃. However, when shortening the reaction time or using condensation components with low activity, higher temperatures (maximum
180℃) is also acceptable. USP.3331687, patent application 1973-
17445 describes a benzylidene fluorene compound, although the 9-(4-N,N-benzylaminobenzylidene) fluorene compound represented by the general formula () according to the present invention has an extended π-electron skeleton. It exhibits high solubility and is extremely useful as a photoconductive material in electrophotographic photoreceptors, and can be sensitized optically or chemically with sensitizers such as dyes and Lewis acids. Examples of the sensitizer include methyl violet,
Triallylmethane dyes such as crystal violet, xanthene dyes such as rose bengal, erythrosine, rhodamine B, thiazine dyes such as methylene blue, 2,4,7-trinitro-9-fluorenone, 2,4-dinitro-9-fluorenone, etc. can be mentioned. Also, organic pigments such as CI Pigment Blue
25 (CI No. 21180), CI Pigment Red 41
(CI No. 21200), CI Basic Cred 3 (CI
Azo pigments such as CI Pigment Blue 16 (CI No. 74100), CI Butt Brown 5 (CI No. 73410),
It can be used in combination with indigo pigments such as CI Butto Dye (CI No. 73030) and perylene pigments such as Argo Scarlet B and Indance Scarlet R, and more favorable results can be obtained thereby. In some cases, inorganic pigments such as selenium, selenium-tellurium, and cadmium sulfide can also be used in combination. Next, the effects of the 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound of the present invention will be explained using an example of its use in a photoreceptor. All parts of the text are 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 was applied onto a polyester film deposited with aluminum using a doctor blade, and air-dried to form a pigment layer with a thickness of 1 μm. Next, 2 parts of 9-(4-N,N-dibenzylaminobenzylidene)fluorene according to the present invention, 3 parts of polycarbonate (Teijin Panlite L) and 45% of tetrahydrofuran.
The resulting solution was applied onto the above pigment layer using a doctor blade and dried at 100° C. for 10 minutes to form a 9 μm thick layer. Next, the photoreceptor thus obtained was tested using an electrostatic copying paper tester.
After applying a 6KV corona discharge for 20 seconds to make it negatively charged, leave it in a dark place for 20 seconds, and then measure the surface potential.
Measure Vpo (volts), then irradiate the surface with light using a tungsten lamp so that the surface illuminance is 20 lux, and the surface potential will be 1/2 of Vpo.
Find the time (seconds) until it becomes halved exposure amount E1/2
(Lutux seconds) was obtained. The results showed extremely high sensitivity values: Vpo = -980 volts and E1/2 = 1.4 lux seconds. The details of the present invention will be shown below with reference to Examples. Example 1 (Production of 9-(4-N,N-dibenzylaminobenzylidene)fluorene by [Method A]) 11.2 g of 4-N,N-dibenzylaminobenzaldehyde and diethyl 9-fluorenylphosphonate
10.2 g was dissolved in 60 ml of ethanol, and a solution of 1.2 g of sodium metal dissolved in 30 ml of ethanol was added dropwise over 5 minutes, followed by heating under reflux for 1 hour. After cooling to room temperature, the precipitated crystals were collected by filtration, washed with water, and dried. Yield 14.3g (yield 94.1%), melting point 124.0-126.0
It was warm at ℃. Recrystallization from a mixed solvent of benzene-n-hexane yielded pure yellow prismatic crystals of 9-(4-N,N-dibenzylaminobenzylidene)fluorene. Melting point: 127.0-127.5°C, elemental analysis: C% H% N% Calculated value as _C34H27N : 90.82 6.70 3.12 _Actual value: 90.81 6.04 3.12 The IR spectrum (KBr tablet method) is shown in FIG. Example 2 (Production of 9-(4-N,N-dibenzylaminobenzylidene)fluorene by [Method B]) 6.0 g of 4-N,N-dibenzylaminobenzaldehyde and 7.2 g of tri-n-butylphosphonium fluorenylide g was added to 120 ml of dry benzene, heated under reflux for 3 hours, allowed to cool to room temperature, and benzene was distilled off under reduced pressure to obtain a yellow oil. A small amount of n-hexane was added to this oil to crystallize it, and the precipitated crystals were collected by filtration and dried. Yield 8.1g (yield 92.0%), melting point 122.5-124.0
℃, from a mixed solvent of benzene-n-hexane to obtain pure crystals of 9-(4-N,N-dibenzylaminobenzylidene)fluorene in the form of yellow prisms. Melting point 126.5-127.5℃ Elemental analysis value C% H% N% C ₃₄ H ₂₇ Calculated value as N 90.82 6.07 3.12 Actual value 90.87 6.05 3.11 The IR spectrum (KBr tablet method) is as shown in Figure 2, which is This completely coincided with FIG. 1 obtained in Example 1. Example 3 In place of 4-N,N-dibenzylaminobenzaldehyde in Examples 1 and 2, the following table shows. 9-(4-N,N-
A dibenzylaminobenzylidene) fluorene compound was produced. The yield, melting point, and elemental analysis values of each compound were as shown in the table.

【table】

【table】 [Brief explanation of the drawing]

Figures 1 and 2 show 9-(4) obtained by the present invention.
-N,N-dibenzylaminobenzylidene) IR spectrum of fluorene.

Claims (1)

[Claims] 1 General formula (1) (In the formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group) 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound. 2 General formula () and () (In the formula, R' represents a lower alkyl group having 1 to 4 carbon atoms.) (wherein R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group) is reacted in the presence of a strong basic alkali compound in an organic solvent () (In the formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group.) A method for producing a 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound. 3 formula () Tri-n-butylphosphonium fluorenylide represented by the general formula () (In the formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group) is reacted in an organic solvent. (In the formula, R represents hydrogen, a lower alkyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group.) A method for producing a 9-(4-N,N-dibenzylaminobenzylidene) fluorene compound.