JP2509040B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member and an electrophotographic apparatus equipped with the photosensitive member.
The present invention relates to a panchromatic electrophotographic photosensitive member having high sensitivity over a wide wavelength range from visible to infrared and an electrophotographic apparatus including the photosensitive member.

[0002]

2. Description of the Related Art As an electrophotographic photoreceptor using an organic photoconductor, a laminated photoreceptor obtained by laminating a charge transport layer containing a charge transport material and a charge generating layer containing a charge generating material has been already available. It has been put to practical use. In such a photoreceptor, a photoreceptor having a desired spectral sensitivity can be obtained by appropriately selecting a charge generation material, but in order to obtain a (panchromatic) photoreceptor having a particularly wide photosensitive wavelength range. , 2 with different photosensitive wavelength range
It is known to mix or stack one or more charge generating materials.

[0003]

However, although the absorption wavelength range is widened by mixing or stacking, the characteristics of each charge generation material may not be sufficiently exhibited, or conversely, the characteristics may be further deteriorated. However, the sensitivity was not always sufficient.

Accordingly, it is an object of the present invention to improve the above-mentioned drawbacks and to provide an electrophotographic photoreceptor having high sensitivity and excellent electrophotographic characteristics over a wide wavelength range.

[0005]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following substances (A) and (B) (A) CuKα characteristic X. Diffraction angle in line diffraction 2θ ± 0.
2 ° 9.0 °, 14.2 °, 23.9 ° and 27.
An oxytitanium phthalocyanine (B) having a peak having an intensity from the maximum to the fourth at 1 ° (B), which contains a charge generating material having a maximum absorption wavelength at 450 to 650 nm,
And an electrophotographic apparatus and a facsimile equipped with the photoconductor.

The present invention will be described in more detail below.

In the present invention, oxytitanium phthalocyanine having a specific crystal form (hereinafter sometimes abbreviated as TiOPc) is used as a charge generating material having a maximum absorption wavelength on the long wavelength side around 600 to 800 nm.

TiOPc is known to have high sensitivity in the above long wavelength region, but among many crystal forms,
The diffraction angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction used in the present invention is 9.0 °, 14.2 °, 23.9 °.
And TiOPc in crystalline form with peaks having intensities from maximum to fourth at 27.1 ° have very high sensitivity.

Therefore, the charge generation material having the maximum absorption wavelength on the short wave side of 450 to 650 nm (hereinafter referred to as substance (B))
Abbreviated), a sufficient sensitivity can be obtained even if the content ratio thereof is small.

This also means that the content ratio of the substance (B) can be increased. Therefore, the characteristics of the substance (B) can be fully utilized without impairing the sensitivity on the short wavelength side. Furthermore, when mixed, the number of contact points between the substance (B) and TiOPc is small, so that the existence of a particle interface barrier is small, and deterioration of memory characteristics, repeating characteristics and the like can be suppressed.

On the other hand, even when the charge generation layer has a laminated structure of a layer containing TiOPc and a layer containing the substance (B), the layer of TiOPc can be made thin, so that the total layer thickness can be kept small. It is possible to improve the memory characteristics and the like.

As the substance (B) used in the present invention, from 450 to 500 of pyrylium dyes, thiapyrylium dyes, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, triazo pigments and disazo pigments.
A material having a maximum absorption wavelength near 650 nm is appropriately selected. Specific examples of these include the following as the central skeleton in the disazo pigment.

[0013]

Embedded image

[0014]

Embedded image As a concrete example of the coupler part,

[0015]

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[0016]

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[0017]

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[0018]

[Chemical 6]

[0019]

[Chemical 7] and so on.

In addition, the following compounds and their derivatives are also included.

[0021]

Embedded image Of course, the substance (B) used in the present invention is not limited to these.

The general formula of oxytitanium phthalocyanine used in the present invention is shown below.

[0023]

[Chemical 9] _{However, X 1, X 2, X} 3, X 4 is n represents Cl Moreover Br, m, k, j is an integer of 0-4.

In the present invention, the content ratio of the substance (B) to TiOPc is preferably set to 50/1 to 2/1, more preferably 20/1 to 5/1. When the amount of the substance (B) is more than 50/1, the sensitivity on the long wavelength side tends to be insufficient,
If the amount of the substance (B) is less than 2/1, the sensitivity on the short wavelength side tends to be insufficient.

When the charge generating materials are mixed in forming the photosensitive layer, each material is dispersed in an appropriate binder resin and a solvent in a ratio within the above range, or individually dispersed liquids are mixed in a predetermined ratio. Mix so that When dispersed individually, different binder resins and different solvents may be used. In the case of stacking, the individually dispersed liquids are applied in respective film thicknesses such that the amount of the contained material becomes a predetermined ratio.
At this time, it is preferable that the layers of the substance (B) are stacked in such an order that they are closer to the light source.

Examples of the binder resin used here include polyester resin, acrylic resin, polyvinyl carbazole resin, phenoxy resin, polycarbonate resin, polyvinyl butyral resin, polystyrene resin, polyvinyl acetate resin, polysulfone resin, polyarylate resin, and chloride. Vinylidene / acrylonitrile copolymer resin and the like are mainly mentioned.

As the constitution of the photoreceptor of the present invention, both a laminated type of a charge generating layer and a charge transporting layer or a single layer type in which a charge generating material and a charge transporting material are mixed are applied. Further, in the former case, there are two stacking orders, but the structure in which the charge generation layer and the charge transport layer are stacked in this order from the support side is common. The configuration of the photoconductor will be described by taking the configuration as an example.

Any conductive material may be used as the conductive support, and a metal such as aluminum or stainless steel may be used.
Alternatively, examples thereof include metal, plastic, and paper provided with a conductive layer, and examples of the shape include a cylindrical shape and a film shape.

Further, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support and the photosensitive layer.

As the material of the undercoat layer, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, methyl cellulose, casein, polyamide, glue, gelatin and the like are used.

These are dissolved in a suitable solvent and coated on a conductive support.

Further, it is preferable to provide a conductive layer between the support and the undercoat layer for the purpose of covering unevenness and defects of the substrate and preventing interference fringes due to scattering when the image input is laser light. is there. This can be formed by dispersing conductive powder such as carbon black, metal particles or metal oxide in a binder resin. The thickness of the conductive layer is 5 to 40 μm, preferably 10 to 30 μm.

The charge transport layer is mainly formed by coating and drying a paint in which a charge transport material and a binder resin are dissolved in a solvent.

Examples of the charge transport material used include various triarylamine compounds, hydrazone compounds, stilbenzene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds and triallylmethane compounds. As the binder resin, the same resin as that used for the charge generation layer can be used.

As the coating method of these photosensitive layers, a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method and the like can be used.

FIG. 1 shows a schematic structural example of a general transfer type electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 is a drum type photosensitive member of the present invention as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. The photosensitive member 1 is uniformly charged at its peripheral surface by a charging unit 2 at a predetermined positive or negative potential in the course of its rotation, and then at an exposure unit 3 an optical image exposure L (slit exposure Laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photoconductor.

The electrostatic latent image is then toner-developed by the developing means 4 and the toner-developed image is rotated by the transfer means 5 between the photosensitive member 1 and the transfer means 5 from a paper feeding portion (not shown). The images are sequentially transferred onto the surface of the transfer material P that has been synchronized and fed.

The transfer material P which has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where the image is fixed and is printed out as a copy.

After the image transfer, the surface of the photosensitive member 1 is cleaned by the cleaning unit 6 to remove residual toner after transfer, and is further discharged by the pre-exposure unit 7 to be repeatedly used for image formation.

As the uniform charging means 2 for the photosensitive member 1, a corona charging device is generally widely used. In addition, the transfer device 5
Corona transfer means are also widely used. The electrophotographic apparatus is configured by integrally combining a plurality of constituent elements such as the photoconductor, the developing unit, and the cleaning unit described above as an apparatus unit, and the unit is configured to be detachable from the apparatus body. May be. For example, the photoconductor 1
Alternatively, the cleaning unit 6 and the cleaning unit 6 may be integrated into one unit, and may be detachably configured by using a guide unit such as a rail of the apparatus main body. At this time, the above device unit may be provided with a charging unit and / or a developing unit.

When the electrophotographic apparatus is used as a copying machine or a printer, the optical image exposure L converts the transmitted light of the reflected light from the original document or the original document into a signal, and scans the laser beam and the LED array by this signal. Drive or liquid crystal shutter array drive.

When used as a printer for a facsimile, the optical image exposure L becomes an exposure for printing received data. FIG. 2 is a block diagram showing an example of this case.

The controller 11 controls the image reading section 10 and the printer 19. The entire controller 11 is CP
It is controlled by U17. The read data from the image reading unit 10 is transmitted to the partner station through the transmission circuit 13. The data received from the partner station is sent to the printer 19 through the receiving circuit 12. The image memory 16 stores predetermined image data. The printer controller 18 controls a printer 19. 14 is a telephone. The image information received from the line 15 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 12, then decoded by the CPU 17, and sequentially stored in the image memory 16. . When the image information of at least one page is stored in the memory 16, the image recording of that page is performed. The CPU 17 reads out one page of image information from the memory 16, and the printer controller 18
The decoded image information of one page is transmitted to the. Upon receiving the image information of one page from the CPU 17, the printer controller 18 controls the printer 19 to record the image information of the page.

The CPU 17 is receiving the next page while the printer 19 is recording.

The image is received and recorded as described above.

The electrophotographic photoreceptor of the present invention can be used not only in an electrophotographic copying machine, but also in a laser beam printer and a CRT.
It can be widely used in electrophotographic application fields such as printers, LED printers, liquid crystal printers, and laser plate making.

Next, a production example of TiOPc used in the present invention will be described. [Production Example] In 100 g of α-chlornaphthalene, 5.0 g of o-phthalodinitrile and 2.0 g of titanium tetrachloride were added to 200 g.
After heating and stirring at 3 ° C for 3 hours, the mixture was cooled to 50 ° C and the precipitated crystals were separated by filtration to obtain a paste of dichlorotitanium phthalocyanine. Then heat it to 100 ° C. N,
The mixture was washed with 100 ml of N'-dimethylformamide under stirring, then washed twice with 100 ml of methanol at 60 ° C., and separated by filtration. Further, the obtained paste was mixed with 100 ml of deionized water at 80 ° C. for 1 hour.
After stirring for an hour and filtering, blue oxytitanium phthalocyanine crystals were obtained. Yield 4.3g.

The elemental analysis values of this compound were as follows. Elemental analysis value (C ₃₂ H ₁₆ N ₈ TiO) C H N Cl calculated value (%) 66.68 2.80 19.44 0.00 Measured value (%) 66.50 2.99 19.42 0.47 Next, dissolve the crystals in 30 ml of concentrated sulfuric acid,
Amorphous oxytitanium phthalocyanine was obtained after dropping into 300 ml of deionized water at 0 ° C. under stirring to cause reprecipitation, filtration, and thorough washing with water. 3. Amorphous oxytitanium phthalocyanine thus obtained
0 g in 100 ml of methanol at room temperature (22 ° C)
The suspension was stirred and stirred for 8 hours, filtered, and dried under reduced pressure to obtain low crystalline oxytitanium phthalocyanine. Next, 40 ml of n-butyl ether was added to 2.0 g of this oxytitanium phthalocyanine, and milling treatment was carried out at room temperature (22 ° C.) for 20 hours together with 1 mmφ glass beads.

The solid content was taken out from this dispersion, thoroughly washed with methanol and then with water, and dried to obtain a novel crystalline oxytitanium phthalocyanine of the present invention. Yield 1.8g. This oxytitanium phthalocyanine has a diffraction angle 2θ ± 0.2 ° of 9.0 ° and 14. ° in X-ray diffraction.
It had peaks with maximum to fourth intensity at 2 °, 23.9 ° and 27.1 °.

[0051]

EXAMPLES Next, the present invention will be explained according to examples. [Example 1] 50 parts of titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of resol type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol
Parts and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average molecular weight 3000)
0.002 parts were dispersed for 2 hours by a sand mill using φ1 mm glass beads to prepare a conductive layer coating material.

Aluminum cylinder (φ80 mm × 3
60mm), and apply the above coating by dip coating,
It was dried for 0 minutes to form a conductive layer having a film thickness of 20 μm.

A solution prepared by dissolving 5 parts of 6-66-610-12 quaternary polyamide copolymer resin in a mixed solvent of 70 parts of methanol and 25 parts of butanol was applied by a dipping method and dried to obtain a layer having a thickness of 1 μm. A pulling layer was provided.

Next, 1 part of the oxytitanium phthalocyanine crystal obtained in Production Example 1 of the present invention and 7 parts of the cisazo pigment having the following structure were dissolved in 100 parts of cyclohexanone.

[0055]

[Chemical 10] Polyvinyl butyral resin (Product name: S-REC BM-
2, manufactured by Sekisui Chemical Co., Ltd.), dispersed in a sand mill using 1 mmφ glass beads for 2 hours, added with 100 parts of methyl ethyl ketone, diluted and recovered,
This was applied onto the undercoat layer and then dried at 80 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.15 μm. still,
The maximum absorption wavelength of this pigment (substance (B)) is 550 nm.

Next, the following structural formula

[0057]

[Chemical 11] A solution was prepared by dissolving 10 parts of the charge transporting material represented by and 10 parts of bisphenol Z-type polycarbonate resin in 60 parts of monochlorobenzene, and applied on the charge generating layer by a dipping method. This was dried at a temperature of 110 ° C. for 1 hour to form a charge transport layer having a thickness of 24 μm. [Examples 2 and 3] A photoconductor was prepared in the same manner as in Example 1 except that the disazo pigment having the following structure was used as the substance (B).

[0058]

[Chemical 12] The maximum absorption wavelength of this pigment is 580 nm.

[0059]

[Chemical 13] The maximum absorption wavelength of this pigment is 560 nm. [Comparative Example 1] A photoreceptor was prepared in the same manner as in Example 1, except that a disazo pigment having the following structure was used instead of TiOPc.

[0060]

Embedded image The maximum absorption wavelength of this pigment is 780 nm. Comparative Example 2 A photoconductor was prepared in the same manner as in Comparative Example 1, except that the ratio of the disazo pigment to the substance (B) was changed to 3: 5.

These Examples 1, 2, 3 and Comparative Example 1,
A copying machine (trade name NP-483) which uses a halogen lamp as an image exposure light source for the photoreceptor obtained in No. 2 and further has an erase exposure means by a semiconductor laser (wavelength 785 nm).
5: manufactured by Canon) and evaluated for electrophotographic characteristics.
Table 1 shows the changes in the surface potential when the light potential was 130 V when the dark potential was -650 V, the laser light amount when the potential after erasing was 80 V, and the 1000-sheet continuous copy. Show.

[0062]

[Table 1] As shown here, the photoconductor of the embodiment of the present invention has high sensitivity in both the visible light source and the infrared laser light source, and at the same time, the potential stability during continuous copying is sufficient, and excellent characteristics are exhibited. Show. On the other hand, in the comparative example, the sensitivities of both light sources are not satisfied, and the continuous potential change due to the deterioration of the memory characteristics is large. [Example 4] A polyvinyl butyral resin obtained by dissolving 5 parts of TiOPc of Production Example 1 in 200 parts of cyclohexanone after coating the undercoat layer in the same manner as in Example 1 (trade name S-Rex BX-1, manufactured by Sekisui Chemical Co., Ltd.) 1m in addition to 3 parts
The mixture was dispersed in a sand mill using mφ glass beads for 2 hours, diluted with 200 parts of methyl ethyl ketone, and then recovered, which was applied onto the undercoat layer. The film thickness was adjusted so that the TiOPc content in the layer was 40 mg / m ² . Next, as a substance (B), 8 parts of an anthanthrone compound having the following structure (maximum absorption wavelength 520 nm) was added to cyclohexanone 100

[0063]

Embedded image In addition to 4 parts of polyvinyl butyral (trade name: S-REC BL-S, manufactured by Sekisui Chemical Co., Ltd.) dissolved in 1 part, it was dispersed in the same manner and laminated-coated on the TiOPc. The film thickness was adjusted such that the content of (B) in the layer was 240 mg / m ² .

A charge transport layer was formed thereon in the same manner as in Example 1. These photoreceptors were evaluated as described above. The results are shown in Table 2.

[0065]

[Table 2] In the copying machine NP-4835 used for the measurement, an erasing light source equipped with an LED of 680 nm instead of the semiconductor laser was prepared, and the LED light amount when the potential after erasing was 130 V was measured in the same manner.
Table 3 shows the results.

[0066]

[Table 3]

[0067]

As is apparent from the above examples, the photoconductor of the present invention has high sensitivity in a wide wavelength range from visible light to infrared light and maintains good potential stability during durability. It has excellent electrophotographic characteristics such as

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Kanamaru 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yama-saki-to 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hideki Anayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Junichi Kishi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In-house (72) Inventor Hideyuki Ainoya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroshi Aoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56 ) Reference JP 63-142356 (JP, A) JP 63-38942 (JP, A) JP 2-267563 (JP, A) JP 3-37660 (JP, A) JP 3-37661 (JP, A) JP Akira 62-67094 (JP, A) JP flat 4-163558 (JP, A)

Claims (5)

(57) [Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following substances (A) and (B) (A) CuKα characteristic X-ray diffraction diffraction angle 2θ ± 0.
2 ° 9.0 °, 14.2 °, 23.9 ° and 27.
An electrophotographic photosensitive member comprising an oxytitanium phthalocyanine (B) having a peak having a maximum intensity at 1 ° to a fourth intensity (B) and a charge generating material having a maximum absorption wavelength at 450 to 650 nm. 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer has a charge generation layer and a charge transport layer, and the charge generation layer contains the substances (A) and (B). 3. The electrophotographic photoreceptor according to claim 2, wherein the charge generation layer has a layer containing the substance (A) and a layer containing the substance (B). 4. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 5. A facsimile comprising the electrophotographic photosensitive member according to claim 1 and further comprising receiving means for receiving image information from a remote terminal.