JPH01226859A - Benzylideneindene compound - Google Patents

Abstract

NEW MATERIAL:A compound expressed by the formula (R<1> is lower alkyl, benzyl or phenyl; R<2> is benzyl or phenyl; dotted line represents that R<2> may form a ring together with a benzene ring). EXAMPLE:1-{4-[N,N-Bis(4-tolyl)amino]benzylidene}indene. USE:Useful as an organic photoconductive material for electrophotography and especially as a charge transfer substance of photosensitive layer of photosensitive material for electrophotography because of being sensitized optically and chemically by a sensitizer such as dye or Lewis acid. PREPARATION:An aldehyde compound is reacted with indene in the presence of a basic catalyst (e.g., sodium hydroxide) in a solvent such as methanol at ambient temperature - 100 deg.C to provide the compound expressed by the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field] The present invention relates to novel benzylidene indene compounds useful as organic photoconductive materials for electrophotography.

[Prior art]

Conventionally, organic photoconductive materials for photoreceptors used in electrophotography include, for example, poly-N-vinylcarbazole and triphenylamine compounds (U.S. Pat. Nos. 3 and 1).
80,730), benzidine compounds (U.S. Pat. No. 3,
A number of proposals have been made, such as Japanese Patent Publication No. 265,496, Japanese Patent Publication No. 39-11546, Japanese Patent Application Laid-Open No. 53-27033).

The "electrophotographic method" referred to here generally refers to a method in which a photoreceptor is first electrically charged in a dark place by, for example, corona discharge, and then image-form fog light is applied to selectively discharge the charge in the exposed areas. This is one of the image forming methods in which an electrostatic latent image is obtained, and this latent image portion is visualized by a developing means using toner or the like to form an image. 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 be charged to an appropriate potential by light irradiation. Examples include quickly discharging charges. However, the reality is that conventional photoconductive organic materials do not necessarily satisfy these requirements.

〔the purpose〕

An object of the present invention is to provide a new benzylidene indene compound that satisfies all basic electrophotographic properties and is useful as a photoconductive material.

〔composition〕

According to the present invention, the following general formula (1) (wherein R1 represents a lower alkyl group, a benzyl group, or a substituted or unsubstituted phenyl group, and R8 represents a benzyl group or a substituted or unsubstituted phenyl group. The broken line represents Indicates that R2 and the benzene ring may cooperate to form a ring.) A benzylidene indene compound represented by the following is provided.

The benzylidene derivative represented by this general formula (1) is
It is obtained by reacting indene with an aldehyde compound represented by the following general formula (II) in the presence of a basic catalyst at a temperature from room temperature to about 100°C.

(In the formula, R1 and R2 are the same as above.) Examples of the basic catalyst include caustic soda, caustic potash, lithium methoxide, and sodium methoxide.

Reaction solvents include methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2
-dimethoxyethane, bis(2-methoxyethyl) ether, dioxane, tetrahydrofuran, toluene, xylene, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-
Examples include 2-imidazolidinone.

The reaction temperature varies over a wide range depending on 1) the stability of the solvent used against the basic catalyst, 2) the reactivity of the condensation components (general formula (II) and indene), and 3) the reactivity as a condensing agent in the basic catalyst. You can choose. For example, when using a polar solvent, the temperature is actually room temperature to 100°C, preferably room temperature to 80°C.

However, when the reaction time is shortened or a condensing agent with low activity is used, higher temperatures may be used. Examples of novel benzylidene indene derivatives according to the present invention obtained in this manner are as follows.

[Benzylidene indene compound]

The novel benzylidene indene compound obtained by 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. . Furthermore, this material is particularly useful as a charge transport material in so-called functionally separated photoreceptors in which an organic pigment or an inorganic pigment is used as a charge generating material.

Examples of the sensitizer include triarylmethane dyes such as methyl violet and crystal violet, xanthine dyes such as rose bengal, erythrosine, and rhodamine, thiazine dyes such as methylene blue, etc.
-Dolinitro-9-fluorenone, 2,4-dinitro-
Examples include 9-fluorenone.

In addition, as an organic pigment, C.I. Pigment Blue 25 (
CI Nn21180), CI Pigment Red 4
1 (CI &21200), azo pigments such as CI Pigment Red 3 (CIN α45210), phthalocyanine pigments such as CI Pigment Blue 16 (CI N1174100), CI Butt Brown 5 (C
I Arashi 73410), CI Batdai (CI Nn7)
3030), etc., Argo Scarlet B
, and perylene pigments such as Indanthrene Scarlet R. Inorganic pigments such as selenium, selenium-tellurium, cadmium sulfide, and α-silicon can also be used.

〔effect〕

The novel benzylidene indene compound shown in (1) above according to the present invention functions effectively as a photoconductive material as described above, and can be optically or chemically treated with a sensitizer such as a dye or a Lewis acid. Because it is sensitized to
It is suitably used as a charge transport material for the photosensitive Mj of an electrophotographic photoreceptor, and is particularly useful as a charge transport material in a so-called functionally separated photosensitive layer in which a charge generation layer and a charge transport layer are divided into two layers.

〔Example〕

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

Example 1 1.16 g (0.01 mol) of indene and 4-(N,N
-bis(4-tolylaminocobenzaldehyde 3.01
g (0.01 mol) was added to 50 cc of dehydrated ethanol, and the mixture was heated to reflux under a nitrogen gas atmosphere. Then, 15 cc of a saturated ethanol solution of potassium hydroxide was gradually added, and after heating under reflux for an additional 2 hours, the mixture was poured into 150 cc of water, and the product was extracted with toluene. This organic layer was washed with water, dried, and then toluene was distilled off. Next, the obtained solution was dissolved in a small amount of toluene and subjected to column chromatography (silica gel: Fuco-
Gel C-200; developing solution, n-hexane/toluene = 1
:1) L, and then the solvent was distilled off. This product was then recrystallized from a mixed solvent of ethyl acetate and ethanol to obtain 1.27 g of 1-(4-(N,N-bis(4-tolyl)aminocobenzylidene)indene as orange needle crystals (yield: 31.8).
%) was obtained. The melting point and elemental analysis values are shown in Table-2.

Examples 2 to 7 Various benzylidene indenes were prepared in the same manner as in Example 1, except that the aldehyde compounds shown in Table 1 were used instead of 4-[N,N-bis(4-tolyl)aminocobenzaldehyde. The compound was obtained. Table 2 shows the melting points and elemental analysis values of these compounds.

Table 1 Table 2 Infrared absorption spectra of the compounds obtained in Examples 1 to 9 are shown in FIGS. 1 to 9.

Application Example As a charge generating substance, 7.5 parts of the following bisazo compound and 0.0 parts of polyester resin [■Vylon 200 manufactured by Toyobo Co., Ltd.] were used.
500 parts of a 5% tetrahydrofuran solution was pulverized and mixed in a ball mill, the resulting dispersion was applied onto an aluminum-deposited polyester film using a doctor blade, and air-dried to form a charge generation layer about II Ja thick. Resin (-1300 for Panlight made by Ondai)
2 parts of the compound of Example 1 as a charge transport substance was dissolved in a resin solution of 1 part of tetrahydrofuran and 8 parts of tetrahydrofuran, and this solution was applied onto the charge generation layer using a doctor blade and heated at 80°C.
for 2 minutes, then dried at 120℃ for 5 minutes to a thickness of approximately 20℃.
．． A charge transport layer was formed.

Next, in order to examine the sensitivity of the laminated electrophotographic photoreceptor thus obtained in the visible range, this photoreceptor was tested at 16 KV in a dark place using an electrostatic copying paper tester [Type 5P428 manufactured by Kawaguchi Electric Manufacturing Co., Ltd.]. After charging by performing corona discharge for 20 seconds, dark decay was performed for 20 seconds, the surface potential Vo (volt) at this time was measured, and then tungsten lamp light was irradiated so that the illumination intensity on the photoreceptor surface was 20 Qux. Find the time (see) until the surface potential becomes 1/2 of Vo, and calculate the half-reduction exposure amount El/2 (uux-se) as the sensitivity in the visible range.
c) was calculated. As a result, Vo is -11144 volts,
Moreover, E1/2 was 1.1 flux-sec.

[Brief explanation of the drawing]

1 to 9 are infrared absorption spectra of the compounds obtained in Examples 1 to 9 of the present invention.

Claims (1)

[Claims] (1) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 is a lower alkyl group, a benzyl group, or a substituted or unsubstituted phenyl group, and R^2 is a benzyl group. Or represents a substituted or unsubstituted phenyl group.The broken line is R^
This shows that 2 and the benzene ring may work together to form a ring. ) A benzylidene indene compound represented by