JPS6348554A - electrophotographic photoreceptor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention is an electrophotographic light-sensitive material that has excellent flexibility and adhesion to a conductive support without reducing dark resistance or photosensitivity. Regarding.

[Traditional technique]

Conventionally, as electrophotographic photosensitive materials, zinc oxide, which is known in many types as inorganic and organic photoconductive substances,
Inorganic photoconductors such as selenium or cadmium sulfide have excellent properties in terms of photosensitivity, but
There are problems with lightness, flexibility, and pollution.

On the other hand, organic leading i! A far greater number of substances are known than inorganic substances, and examples of low-molecular organic photoconductive substances include phthalocyanine, metal-free 7-thalocyanine, and oxadiazole derivatives. ,
94 benzimidazole compounds, etc., and as polymer type organic phototetraelectric substances, for example, Japanese Patent Publication No. 42-1867
Publication No. 4.

Polymers containing a heterocyclic ring such as a carbazole ring, a certain 1ρ, a polynuclear aromatic ring such as a naphthalene ring and an anthracene ring as disclosed in Japanese Patent Publication No. 42-25250 are known.

[Problem to be solved by the invention]

These organic photoconductive materials have excellent occupancy, light fjt property, and non-polluting properties as essential characteristics of organic materials.
It has significantly lower photosensitivity than inorganic materials, and there are many points that need to be improved based on its physical properties. Regarding the former, light sensitivity, useful organic photoconductive substances and sensitizers have been disclosed due to advances in Ariiso synthesis technology, and their practical value has increased dramatically. However, there are many problems regarding the physical properties of the latter, which is a major obstacle to the practical application of organic photoconductive materials.For example, polymer-type organic photoconductive materials have strong intermolecular cohesive forces and It often crystallizes, impairs transparency, is generally hard and brittle, and has drawbacks such as poor adhesion to the support.For low-molecular-weight organic photoconductive materials, the method for forming a photosensitive layer is , vapor deposition, or dispersion or dissolution in resin, etc., but in the case of vapor deposition σ],
There are problems with flexibility, close layering with the support, efficiency and cost when forming a photosensitive layer, and when dispersing or dissolving in a resin, flexibility and adhesion with the support are 1. This is largely determined by the properties of the resin that is the binder, but the rubber resins used to date do not have sufficient flexibility or adhesion to the support, and these properties are not good. However, they did not provide satisfactory results because they faced a moving bed that impaired desired electrophotographic properties, such as a decrease in surface potential and a decrease in photosensitivity.

The invention is intended to solve the above-mentioned problems, and its purpose is to create an electronic material that has excellent flexibility, hardness, and adhesion to the support without deteriorating the electrophotographic characteristics. The company provides photographic materials.

[Means to solve the problem]

The electrophotographic photoreceptor according to the invention is characterized by containing an organic photoconductive substance and a photocurable resin.

[Example 1] Copper phthalocyanine (Sumitone Oyanine)
BlueLBGIJ, Sumitomo Chemical) 3'? , photocurable resin (Threepond 3070. Suribond Co., Ltd.)
41. Polyincyanate (Japan Polyurethane) 1,
A mixed solution (1:1) of methyl ethyl ketone (hereinafter MEX) and toluene 70? Mix and mill in a ball mill.
It was dispersed for 4 hours. This is called liquid A.

Polycarbonate (N0VAREX, Mitsubishi Kasei) 21
．． Diphenylhydrazone derivative (OTO-236, MN
Fragrance industry) 2 and tetrahydrofuran (hereinafter referred to as T) 1?
) Dissolve in 10r and use this as liquid B.

A polyester film (high beam I QOL) with a transparent 2# electrical layer of indium tin oxide (hereinafter referred to as TO
-BKO2, Azuma) as a support, liquid A is applied thereto, and the solvent is removed by hot air drying to form a charge generation layer with a thickness of 1 μm.

Further, liquid B is applied thereon and the solvent is removed in the same manner to form a charge transfer layer having a thickness of 20 μm. This is called an electrophotographic photoreceptor 1.

In addition, a polyester resin (Byron 200. Toyobo) was used instead of the photocurable resin in the A liquid, and 1A was used as the C liquid and applied in the same manner instead of the above A liquid, and this was used as the charge generation layer. The photographic photoreceptor is referred to as a t-child photographic photoreceptor 10.

Table 1 shows the measurement results of the flexibility, tightness with the support, and photosensitivity of the electrophotographic photoreceptors 1 and 10.

Flexibility is achieved by wrapping the photoconductive layer (charge generation layer and charge transport layer polished on top) around cylinders with several different diameters, so that cracks can occur in the photoconductive layer. Expressed in diameter. Practically, a value of 5rtrm or less is required,
Preferably, the value is 3rttrn or less.

The hardness with respect to the support was investigated using a pencil hardness tester (manufactured by Toyo Seiki). The load was 1 and the angle of contact of the core was 45 degrees. Five samples were measured, and if three or more were good, the electrophotographic photoreceptor was considered to be good. Practically speaking, the hardness is HB, preferably 2H or higher. Adhesion to the support was determined by a cross-cut test, and those that did not peel off at all were evaluated as ○ and 1.
Those with peeling of less than 1% were evaluated as Δ, and those with peeling of 1% or more were evaluated as ×.

The photosensitivity was compared using a static copy paper tester (SP-428° Kawaguchi Denki Co., Ltd.) using the amount of exposure until the initial surface potential was halved due to light attenuation (half-attenuated amount of light).

[Example-2] Example 1 Metal-free phthalocyanine (Dainippon Ink) was used in place of 10 kg of copper phthalocyanine, and the liquid was adjusted to be similar to that of A liquid, and this was used as liquid D. Similarly to Example 1, D liquid engineering T
After coating and drying on a polyester film having the following properties, liquid B is coated to form an electrophotographic photoreceptor 3 in which a charge transfer layer is laminated on the charge generation layer.

In addition, in the D solution, polyvinyl butyral resin (5-LKC, BM-2, yI water chemistry) is used instead of the photocurable resin.
The electrophotographic photoreceptor 20 is prepared by using the liquid E as the electrophotographic photoreceptor, which is similarly coated in place of the above liquid, and uses this liquid as a charge generation layer.

Table 1 shows the measurement results of the flexibility, adhesion to the support, hardness, and photosensitivity of the electrophotographic photoreceptors 2 and 20.

・[Example 3] Metal-free phthalocyanine (RAS?) was used in place of the copper phthalocyanine in solution A of Example 1, and n-arranged in the same manner as A'Kz. liquid, and in the same manner as in Example 1,
It is coated on a polyester film with
Poly-N-vinylcarbazole (BASII') 3V, photocurable resin (Phenoto) using this as a charge generation layer.
fP-50, Toi Chemical a) 4y, polyisocyanate (Japan Polyurethane) 11 in THF70? This was used as liquid G, and liquid G was applied in the same manner as liquid B in Example 10 on the charge generation layer formed by applying liquid E to form a charge transfer layer. Create.

In addition, in the E solution, gel vinyl formal resin MC Denka Formal, Denki Kagaku Kogyo Co., Ltd. was used instead of the photocurable resin as the H solution, and in the G solution, Nigiri ester resin (Byron 200) was used instead of the photocurable resin. .Toyobo) is used as 1 liquid, and H liquid and 1 liquid are used respectively.
The electrophotographic photoreceptor 30 is prepared by applying the liquid in the same manner as the liquid and liquid G to form a light guide 'Kffl.

Flexibility of the electrophotographic photoreceptors 3 and 30, adhesion to the support, hardness, and light P! ! The results of the four measurements are shown in Table 1.

Table 1 [Effects of the Invention] From the results of Examples 1 to 3 (Table 1), electrophotographic photosensitive materials having a photoconductive layer according to the invention (in the table).

1 to 3) have excellent foldability and hardness, and have very good adhesion to the support, compared to electrophotographic materials that do not contain a photocurable resin (10 to 30 in Table 1 of Comparative Example 1). It is clear that there is an effect that there is no decrease in photosensitivity.

that's all

Claims (1)

[Claims] An electrophotographic photoreceptor comprising an organic photoconductive substance and a photocurable resin.