JPS5843460A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an easily manufacturable photoreceptor having good both polarity-chargeability and high sensitivity, by adding a squalenic acid methine dye dispersed into a water-soluble polymer to a charge generating layer in a function separation type electrophotographic receptor consisting of a charge generating layer and a charge transfer layer. CONSTITUTION:A squalenic acid dye has a general formula shown in which Z is a hetero ring containing N; X, X1, X2 are each an aromatic ring contg. N or O, optionally substd. by N(C2H5)2, OH, alkyl, or the like. A soln. of this dye dissolved in a water-insoluble solvent is dispersed into an aq. soln. of a water- soluble polymer such as casein, gelatin, or water-soluble polyvinyl butyral, and coated on a conductive substrate to form a charge generating layer after drying. A charge transfer layer contg. a charge transfer agent such as pyrazoline derivatives is formed on the charge generating layer, thus permitting a photoreceptor capable of being charged to both polarities and forming a high-quality image to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor having good charging ability and photosensitivity.

Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used in photosensitive layers used in electrophotographic photoreceptors. In recent years, organic photoconductive substances such as polyvinylcarbazole have been actively researched, and some of them have been put into practical use. This organic photoreceptor has many superior properties than inorganic photoreceptors, and provides a wide range of applications in the field of electrophotography. Furthermore, organic photoreceptors are being actively applied to so-called functionally separated photoreceptors. This function-separated photoconductor black 3 has the high reliability and
It seems to have advantageous conditions such as low maintenance, expansion and diversification of functions, high quality images, ease of operation, and non-pollution. Therefore, the current situation is that considerable efforts have been made in various fields in the past ten years or so to develop this organic photoreceptor. The present inventor was also progressing with the development of a photoreceptor using this organic material, and obtained a photoreceptor with sufficient charging ability and photosensitivity even in positive and negative corona charging with the same charging layer. reached. Furthermore, the manufacturing method is extremely easy and can be done using conventional technology, and does not require any special technology.

That is, the present invention uses methine squarate dye as a compound capable of generating photocarriers when irradiated with light, and provides an electrophotographic photoreceptor having a layer in which this dye is dispersed in a water-soluble polymer. It is related to.

The methine squarate dye used in the present invention has the following general formula [where 2 is a heterocyclic ring containing N, and XXX11X2 is an aromatic ring containing N and/or O or substituted with a functional group. selected from ]. The details are disclosed in US Pat. No. 361,720, Tata No. 312,170, and the like. The ratio of these dyes to water-soluble polymers varies by weight.

It can be used within the range of

Organic primary amines can be used as solvents for this dye. 1 Soluble in water 7 Highly invasive, □ is, ・s4 Normal water solubility: ゛Polymer e.g. casein, gelatin B:
Water-soluble polymers such as vinyl butyral, polyvinyl alcohol, etc. can be used. A layer consisting of this water-soluble polymer and methine squarate dye is used as a charge generation layer. When applied to a functionally separated photoreceptor, most conventionally known compounds can be used as the charge transport layer. Examples include polyvinylcarbazole, pyrazoline derivatives dissolved in polymers, and the like.

The present invention will be specifically explained below with reference to Examples.

Example/'- Methine squarate dye 109 represented by the structural formula (+)
is dissolved in 11O9 of n-butylamine.

Structural formula (+) Add this solution to 60°C water 100% with ammonia water/f
Add cc/llt of casein to the solution.

30 t of N,N-dimethylacetamide was added to the obtained solution, and a stirrer with a cutter blade of 6/0.0
Mix and disperse for 2θ minutes by rotating at 0 Or, pom. The obtained solution was applied to the aluminum side of a polyethylene terephthalate film laminated with aluminum to a thickness of 2 to 5 mm.
Apply to a thickness of μm. This was dried in an atmosphere at 70° C. for 2 hours, and the obtained layer was used as the first layer. On this first layer, a pyrazoline derivative represented by the structural formula (1N) and a polycarbonate (Panlite LX, ZT manufactured by Teijin) were respectively added with an iot of 1009/, /-dichloromethane/
A second layer is formed by applying a solution prepared by dissolving the liquid to a thickness of 10 μm after drying.

Structural formula([) Structural formula shown as methine squarate dye/I67 The procedure is the same as in Example 1, except that the compound described above is used.

Structural Formula (Ill) Example 3 The same as Example 3 except that a compound represented by the structural formula (Ill) was used as the methine squarate dye.

〇・′□:1[) Structural formula ■ Example Hiroshi In Example 1, 71 Kaisho 5 was used instead of the casein aqueous solution.
8-4346 (1(3)

Example j In Example 1, zOwt instead of caseino aqueous solution
-1 polyvinyl alcohol (Nippon Gosei NH-/I
) The procedure is the same except that it is made into an aqueous solution.

Comparative Example 1 Instead of the n-butylamine solution of methine squarate dye in Example 1, ε-type copper phthalocyanine/(Lionol BlueER manufactured by Toyo Ink Manufacturing Co., Ltd.) 10f was used.
, N-dimederacetamide≠02 except that a mixed solution was used.

Comparative Example 2 Instead of the casein aqueous solution in Example 1, 1...
) 1st'-5ne 1-fat (Yotaisha '75'f) Lr/
22k) The procedure is similar, except that a solution of 10t in 20/-dichloroethane is used.

The properties of the photoreceptors obtained in the above Examples and Comparative Examples were measured using Kawaguchi Electric SP-4 (21) and the values are shown in Table 7. In the table, V represents positive, negative, and 4KV corona, respectively. Surface potential [V] immediately after discharging, E) Fij L
Exposure amount until the potential is halved when irradiated with white light of x [
1uX-8eC].

, Gourd 10 As an application example of the present invention, the photoreceptor has sufficiently satisfactory characteristics even when charged with either positive or negative polarity in the same layer, so for example, it is shown in JP-A No. 174-737. A photoconductor for a copying system that can produce two-color copies, a copying system that can easily produce a positive image from either a negative or positive original, a master for electrostatic printing, a photoconductor for color copying, etc. can be considered.

However, the applications of this photoreceptor are not limited to these, and there are few known techniques for easily obtaining a photoreceptor that has good photoreceptor characteristics even when charged with either positive or negative polarity. Examples can be said to be an unknown field.

This provides an effective technology that is expected to find wide application in the future.

patent applicant Tomoekawa Paper Mill Co., Ltd.

Claims (1)

[Scope of Claims] (1) A methine squarate dye is used as a compound capable of generating photocarriers upon irradiation with light, and a layer is provided in which this dye is dispersed in a water-soluble polymer. An electrophotographic photoreceptor featuring: (2) The electrophotographic photoreceptor according to claim 1, wherein the solvent used for dispersing the dye contains water. (3) The electrophotographic photoreceptor according to claim 1, wherein the dye is dissolved in a solvent and then dispersed in a water-soluble polymer. +41 The electrophotographic photoreceptor according to claim 1, wherein the solvent capable of dissolving the dye described in item 1 is insoluble in water. (5) A function-separated type electronic device according to claim 1, characterized in that the layer containing the above dye is used as a charge generation layer, and a layer having a charge transporting ability is formed above or below the layer. Photographic photoreceptor.