JPH02243657A - Stilbene derivative - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (X is Cl; R1 is halogen, cyano, lower alkyl or alkoxy; R2 is H, lower alkyl or alkoxy). EXAMPLE:4-Chloro-4'-N,N-bis(4-methylphenyl)aminostilbene. USE:Useful as a photoconductive material for electrophotographic sensitive materials, charge transfer material for functional separation type photosensitive substances, etc. PREPARATION:A phenyl derivative expressed by formula II [Y is triphenylphosphonium group expressed by formula III (A(-) is halide ion) or dialkyl phosphite expressed by the formula -PO(OR)2 (R is lower alkyl)] is reacted with an aldehyde compound expressed by formula IV to afford the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to novel stilbene derivatives which can be used as organic photoconductive materials and fluorescent brighteners for electrophotography, in particular organic photoconductive materials for electrophotography. This provides a material useful as a material.

BACKGROUND OF THE INVENTION In the past, 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 in a dark place by, for example, corona discharge, 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 satisfy these requirements.

On the other hand, selenium and zinc oxide are known as photoconductive inorganic materials, and among them selenium is widely used in practical use. However, recently, in terms of the electrophotographic process, various demands have been placed on the photoreceptor. For example, in addition to the above-mentioned basic characteristics, there is also a demand for a flexible belt-like photoreceptor in terms of shape. This is becoming more and more common. However, in the case of selenium, it is generally difficult to create such a shape.

Object The object of the present invention is to provide a novel stilbene derivative that is particularly useful as a photoconductive material, which eliminates the above-mentioned drawbacks of photoconductive materials for photoreceptors.

Structure The present invention is based on the general formula (I): cyano group, lower alkyl group or alkoxy group, R2 represents hydrogen, lower alkyl group or alkoxy group. ) is a stilbene derivative represented by

Such stilbene derivatives have the general formula (II) [wherein X
is a triphenylphosphonium group represented by (represents a halogen atom or halogen ion) or a dialkylphosphorous group represented by -PO(OR)2 (where R represents a lower alkyl group); The following general formula (wherein, X
is a chlorine atom, R1 is a halogen atom, and (in the formula, R1 is a halogen atom, a cyano group, a lower alkyl group, or an alkoxy group sR2 is hydrogen, a lower alkyl group, or an alkoxy group) is reacted with an aldehyde compound represented by obtained by

The phenyl derivative represented by the general formula (■) used in the present invention can be prepared by combining the corresponding halomethyl compound and trialkyl phosphite or triphenylphosphine directly or in a solvent such as toluene, tetrahydrofuran, N,N-dimethylformamide, etc. Easily produced by heating.

Here, the trialkyl phosphite is preferably an alkyl group having 1 to 4 carbon atoms, particularly a methyl group or an ethyl group.

The phenyl derivative represented by the general formula (II) thus obtained and the aldehyde compound represented by the general formula <m> are reacted at a temperature from room temperature to about 100° C. in the presence of a basic catalyst.

As basic catalysts, mention may be made of alcoholades such as caustic soda, caustic potash, sodium amide sodium hydride and sodium methylate, potassium-1-butoxide and the like. In addition, reaction solvents include methanol, ethanol, impropatol, butanol, 2-methoxyethanol, 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, dioxane, tetrahydrofuran, toluene, xylene, dimethyl sulfoxide, N
, N-dimethylformamide, N-methylpyrrolidone,
(2), 3-dimethyl-2-imidazolidinone, and the like.

Among them, polar solvents such as N,N-dimethylformamide and dimethyl sulfoxide are preferred.

The reaction temperature depends on l) the stability of the solvent used against the basic catalyst, 2) the reactivity of the condensation components (compounds of general formulas (n) and (III)), and 3) the reaction as a condensing agent in the basic catalyst. You can choose from a wide range of options depending on your gender.

For example, when using a polar solvent, the temperature is actually from room temperature to 10
0°C, preferably room temperature to 80°C. However, when the reaction time is shortened or a less active condensing agent is used, higher temperatures may be used. Examples of novel stilbene derivatives according to the present invention obtained in this way are as follows.

The novel stilbene derivative according to the present invention is extremely useful as a photoconductive material in electrophotographic photoreceptors, and can be optically or chemically sensitized with a sensitizer such as a dye or a Lewis acid.

It is also particularly useful as a charge transfer material in so-called functionally separated photoreceptors that use organic pigments or inorganic pigments as charge generation materials.

Examples of the sensitizers include triallylmethane dyes such as methyl violet and crystal violet; Santen dyes such as rose bengal, erythrosine, and rhodamine B;
Examples include azine dyes such as methylene blue, 2,4.7-)dinitro-9-fluorenone, 2,4-dinitro-9-fluorenone, and the like.

Also, as an organic pigment, C.I. Pigment Blue 25 (
CI No. 21180), CI Pigment Blue 41 (CI No. 21200), CI Basic L/D 3 (CI No. 45210), etc., CI Pigment Blue 16 (CI No.
, 74100), indigo pigments such as C.I. Butt Brown 5 (CI No., 73410), C.I. Violet Dye (CI No., 73030), and perylene pigments such as Argo Scarlet B Intense Scarlet R. It will be done. Inorganic materials such as selenium, selenium-tellurium, cadmium sulfide, and α-silicon can also be used.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 26.28 g of diethyl 4-chlorobenzyl water sulfonate (
0.1 mol) and 30.1 g (0.1 mol) of 4-N,N-bis(4-methylphenyl)aminobenzaldehyde.
was dissolved in 100% N,N-dimethylformaldehyde, and 28% sodium methylate and 27% methyl alcohol solution was added thereto. llTg (Q, 15 mol) from 25 to 3
The dropwise addition took 30 minutes at 0°C. After the addition, the mixture was stirred at room temperature for 2 hours, and the precipitated powder was filtered off, washed with water, and dried to obtain a pale yellow powder. The yield was 37.7 g (92% yield), and the melting point was 133-135°C.

Recrystallization was performed from a mixed solvent of ethyl acetate and ethanol to obtain pure 4-chloro-4°-N,N-bis(4-methylphenyl)aminostilbene in the form of pale yellow needle-like crystals.

Yield 135.4g (yield 8BJ%) Melting point 134.5-1
The 35.5°C elemental analysis infrared absorption spectrum (KBr tablet method) is shown in FIG. 1, and absorption based on CM-out-of-plane bending vibration of the transformer was observed in 9B5ci.

Examples 2 to 11 New stilbene derivatives were obtained in the same manner as in Example 1, except that aldehydes shown in Table 1 below were used instead of 4-N,N-diphenylaminobenzaldehyde. The results are shown in Table-2.

Table-1 Table-2 It is particularly effective as an organic photoconductive material for electrophotography.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum diagram of 4-chloro-4'-N,N-bis(4-methylphenyl)aminostilbene obtained in Example 1.

Claims (1)

[Claims] General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, X is a chlorine atom, R_1 is a halogen atom, a cyano group, a lower alkyl group, or an alkoxy group , R_2 is hydrogen,
Represents a lower alkyl group or an alkoxy group. ) is a stilbene derivative.