JPS63118751A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive layer high in photosensitivity in a wide wavelength region by incorporating 2 kinds of organic photoconductors different in an absorbing wavelength region in the photosensitive layer laminated on a conductive substrate. CONSTITUTION:The 2 kinds of organic photoconductors different in absorbing wavelength region are contained in the photosensitive layer laminated on the conductive substrate. For example, copper phthalocyanine and quinacridone are mixed with polyvinyl butyral, and tetrahydrofuran in prescribed proportion and dispersed in a ball mill. The surface of the polyester film on which ITO is vapor deposited is further coated with this obtained dispersion solution, and dried by passing hot air along it to form the photosensitive layer, thus permitting the obtained photosensitive layer to have high photo-sensitivity in the wide wavelength region.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is applicable to wavelengths from approximately 550 nm to 900 nm. Regarding an electrophotographic photoreceptor having as a constituent element a photosensitive layer having extremely high photosensitivity over a wide range of Im Low-molecular organic photoconductive substances such as talocyanine, oxazole derivatives, benzimidazole derivatives, polymers containing heterocycles such as carbazole rings, and polymers containing polynuclear aromatic rings such as naphthalene rings and anthracene rings. Molecular organic photoconductive substances are known.

Although these organic photoconductive substances have inferior photosensitivity and printing durability compared to inorganic photoconductive substances, they are attracting attention because they are inexpensive, have a simple manufacturing method, and are easy to handle. ] However, organic photoconductors show high sensitivity only to light in a specific wavelength range, which means that most of the light from the light source does not contribute to carrier generation, resulting in low efficiency. It had the disadvantage of being poor. Alternatively, only light sources with wavelengths in the absorption wavelength range can be used (8).

The present invention solves the above-mentioned problems, and its purpose is to
An object of the present invention is to provide an electrophotographic photoreceptor having as a component a photosensitive layer having an absorption wavelength range over a wide range of yn.

[Means for solving problems]

The electrophotographic photoreceptor of the present invention is characterized in that the photosensitive layer laminated on the conductive support contains two or more types of organic photoconductive substances having different absorption wavelength ranges. The present invention will now be described in detail based on examples. Note that the organic light, conductive material, combination thereof, and binder resin that appear in the examples are not limited to these.

[Example 1] Steel 7 talocyanine (Sumitona 0yanine) with 620 ntn and 720y+mK absorption peaks
BlueLBGN, Sumitomo Chemical) 29-540ntn
Quinacridone (Rubicrone) has an absorption peak at
-Feed 500R3, Toyo Soda Kogyo-)1? , polyvinyl butyral (5-IKOBM-8, Tanezu Kagaku)
22, Polycarbonate *-) (N0VARKX, Mitsubishi Kasei) 1f1 Tetrahydro 7 Run 70f was mixed with this dispersion, which was dispersed in a ball mill for 24 hours, and a polyester film (High Beam 1
00 L-EKO2, Higashi) was coated and dried with warm air to form a photosensitive layer with a thickness of 30μ. Copy paper testing device 5
Electrophotographic characteristics were measured using P-428 model (Kawaguchi Electric Seisakusho). The surface potential of the photoreceptor when the surface of the photoreceptor was charged for 5 seconds at a charging voltage of -5.0 kV was then filtered at intervals of 50% m from 350 to 900 n.
Attach the filters (half-width at half maximum ~109 m) to a tungsten lamp light source and irradiate the photoreceptor surface with near-monochromatic light at 100 nW/cII to attenuate the surface potential vO by half. The necessary exposure ff1 (half-reduced exposure amount) E±(μJ//ci) was determined. The results are shown in Figure 1. The vertical axis is the photosensitivity 1/11j1 (,!+1/
μJ). The horizontal axis is the wavelength of light (9@jo).

From the graph, it can be seen that photoreceptors with panchromatic light sensitivity are produced from 550 sfn to 8501 sfn.

[Example 2] One metal-free 7 thalocyanine (Dainippon Ink) having an absorption peak at 620 x poison and 720 nvn, and 530
Tetramethyltriphetdioxazine (Toyo Soda Kogyo ■) 22, which has an absorption peak at /1) This dispersion was mixed with 70f and dispersed in a ball mill for 24 hours.
Coating was carried out in the same manner as above to form a photoreceptor having a thickness of 630 μm.

The results of measurements made on this electrophotographic photoreceptor in the same manner as in Example 1.Same as in Example 1, from 550% to 90%.
It has panchromatic photosensitivity down to 0 nm.

[Example 3] No money! A photoreceptor was formed in the same manner as in Example 2, except that 22 i47 talocyanine and 12 tetramethyltriphetdioxazine were used.

As a result of measuring this electrophotographic photoreceptor in the same manner as in Example 1, it was found that, as in Example 1, from 350 nm to 90
Comparative Example 1 Copper 7 talocyanine (Sumitons 0 ysm) with panchromatic photosensitivity over 0 ysm
BlueLBGN, Sumitomo Chemical) 32, polyvinyl butyral (s-vva BM-3, Tanezu Chemical) 2f
1 Bolicarbonate) (NOVARKX, Mitsubishi Kasei) 1
? , Tetrahydro 7 Run 702 and dispersed in a ball mill for 24 hours. This dispersion was applied in the same manner as in Example 1 to form a comparative photoreceptor having a thickness of 30 μm.

This electrophotographic photoreceptor was measured in the same manner as in Example 1, and the results are shown in FIG.

〔Effect of the invention〕

As described above, according to the present invention, two
By containing more than one type of organic photoconductive substance,
Since it is possible to form a photosensitive layer with extremely high photosensitivity over a wide area from 350n9n to 900m, it is not captured by the light source, that is, it can be used for lasers, halogen lamps, and 10S. , a completely new type of electrophotographic photoreceptor is realized.

[Brief explanation of the drawing]

FIG. 1 is a curve diagram showing the wavelength sensitivity of the photoreceptor of Example 1 of the present invention. FIG. 2 is a curve diagram showing the wavelength sensitivity of the photoreceptor of Comparative Example 1. Applicant: Seiko Epson Corporation 311G 4oom uo 7oo
9~5ft-k of δ <? Ivn)

Claims (1)

[Claims] An electrophotographic photoreceptor characterized in that a photosensitive layer laminated on a conductive support contains two or more types of organic photoconductive substances having different absorption wavelength ranges.