JPH0473945B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an organic semiconductor and an electrophotographic photoreceptor using the semiconductor. To be more specific,
The present invention relates to a photoconductive organic semiconductor and an electrophotographic photoreceptor using the organic semiconductor as a charge transporting material in a photosensitive layer. [Prior Art] In recent years, attempts have been made to use organic materials as electrophotographic photoreceptors. This organic photoreceptor consists of a material that has charge generation ability (hereinafter referred to as charge generation material) and a material that has charge transport ability (hereinafter referred to as charge transport material).
It is used in combination with a charge generation layer and a charge transport layer, or a layer in which a charge generation material is dispersed in a charge transport material. The charges to be transported may be holes or electrons, but a 1:1 mixture of polyvinylcarbazole (PVK) and trinitrofluorenone (TNF) is used as a charge transport material (N-type organic semiconductor) with electron transport ability. In addition, pyrazoline, hydrazone, benzidine derivatives, etc. are known as charge transport materials (P-type organic semiconductors) having hole transport ability (Japanese Unexamined Patent Application Publication No. 1983-1993).
120834 etc.). [Problems to be Solved by the Invention] An object of the present invention is to provide a novel organic semiconductor that can be used as a charge transport material and an electrophotographic photoreceptor using the organic semiconductor. [Means and effects for solving the problem] As a result of extensive research, the present inventors found that the bical basil compound represented by the following general formula () has properties as a P-type semiconductor, and has been found to be suitable for use in electrophotographic photoreceptors. They discovered that it can be used in photosensitive layers and completed the present invention. In the formula, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a substituted amino group, and R ₂ represents a hydrogen atom, an alkyl group, an aralkyl group,
Heterocyclic group or the following formula (In the formula, R ₃ to R ₇ are independent of each other,
hydrogen atom, halogen atom, alkyl group, respectively.
Hydroxy group, alkoxy group, carboxyl group,
Represents an acetyl group, substituted amino group or alkoxycarbonyl group. ) represents an aryl group represented by The bicalbasil compound itself is a compound described in the literature (J.Electrochem.Soc., 122 , 876 (1975), etc.)
It is. Specific examples of compounds of the general formula () that are useful as organic semiconductors and can be used in electrophotographic photoreceptors are shown below in the form of structural formulas. In the structural formula, Me represents a methyl group, Et represents an ethyl group, Pr represents a propyl group, Bu represents a butyl group, and Ac represents an acetyl group. The organic semiconductor of the present invention is uniformly mixed into a binder resin and used as a P-type semiconductor. As the binder resin, commonly used resins such as polycarbonate, polyarylate, polyester carbonate, polystyrene, and styrenic copolymers are used, and 10 to 70% by weight, preferably 30 to 55% by weight of these resins are used. % of the content. The photoreceptor using the organic semiconductor of the present invention has a structure in which a charge generation layer and a charge transport layer containing the organic semiconductor described above are laminated in this order on a substrate (for negative polarity charging), or in a structure in which they are laminated in the reverse order. (for positive charging) or a structure in which a layer in which a charge generation material is dispersed in a charge transport material is provided, and a protective layer may be further provided if desired. As the charge generation layer, Se, Se-Te, Se-As,
Inorganic substances such as ZnO, CdS, and a-Si, or organic substances such as squarerium pigments, phthalocyanine pigments, trisazo pigments, pyrylium dyes, thiopyrylium dyes, and triarylmethane dyes are vapor-deposited or dispersed in resin. layers etc. are used. [Example] Example 1 3 g of the bical basil compound of Example No. 9 and polyester resin (manufactured by Unitika, U-Polymer U-100) were placed on 1μ of the Tri-Se charge generation layer provided on the Al substrate. An electrophotographic photoreceptor was prepared by coating a solution of 3 g dissolved in 34 g of methylene chloride and drying to form a charge transport layer of 25 μm. When the half-decrease exposure amount of this photoreceptor was determined using a conventional charging characteristic measuring device, it was found to be E _1/2 =2.4 lux·sec. Example 2 The half-decreased exposure amount was determined in the same manner as in Example 1 except that the polyester resin was replaced with U-polymer P-3001 manufactured by Unitika, and it was found that E _1/2 = 2.7 lux · seconds. . Example 3 A photoreceptor was prepared in the same manner as in Example 1 using the compound of Specific Example No. 31 as the bical basil compound, and evaluated, and found that E _1/2 =1.3 lux·sec. Example 4 A photoreceptor was prepared in the same manner as in Example 1 using the compound of Specific Example No. 31 as the bical basil compound and polycarbonate (Makrolon 5705) as the binder resin, and was evaluated. E _1/2 = 2.3 It was lux second. Examples 5 to 12 Photoreceptors were prepared in the same manner as in Example 1 using the bical basil compounds shown in Table 1 below, and the charging characteristics were evaluated, and the results shown in Table 1 were obtained.

【table】

〔Effect of the invention〕

Bicalbasil compounds represented by the general formula () are useful as P-type organic semiconductors, and can be used as charge transport layers in electrophotographic photoreceptors.

Claims (1)

[Claims] 1. The following general formula [In the formula, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a substituted amino group, and R ₂ represents a hydrogen atom, an alkyl group, an aralkyl group, a heterocyclic group, or a group of the following formula: (In the formula, R ₃ to R ₇ are independent of each other,
hydrogen atom, halogen atom, alkyl group, respectively.
Hydroxy group, alkoxy group, carboxyl group,
Represents an acetyl group, substituted amino group or alkoxycarbonyl group. ) represents an aryl group represented by ] An organic semiconductor represented by 2. In an electrophotographic photoreceptor in which a photosensitive layer is formed on a substrate, the following general formula is used as a charge transport material for the photosensitive layer. [In the formula, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a substituted amino group, and R ₂ represents a hydrogen atom, an alkyl group, an aralkyl group, a heterocyclic group, or a group of the following formula: (In the formula, R ₃ to R ₇ are independent of each other,
hydrogen atom, halogen atom, alkyl group, respectively.
Hydroxy group, alkoxy group, carboxyl group,
Represents an acetyl group, substituted amino group or alkoxycarbonyl group. ) represents an aryl group represented by ] An electrophotographic photoreceptor characterized by containing an organic semiconductor represented by the following.