JPH03246552A - Electrophotographic sensitive body, facsimile and electrophotographic method using the same - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor containing a fluorine compound, particularly a fluorine surfactant, and an electrophotographic method using the same. The present invention relates to a highly sensitive electrophotographic photoreceptor in which the electrophotographic photoreceptor contained in a conductive layer hardly deteriorates at high temperatures.

[Prior Art] Generally, photoconductors such as selenium, CdS, ZnO, or organic photoconductors are used as photoreceptors in electrophotographic devices such as copying machines and printers.

However, they generally suffer from image changes due to environmental conditions such as temperature and humidity, and in some cases remain problematic in that they are difficult to put into practical use.

In order to solve these drawbacks, conventional measures have been taken such as attaching a heating device to the photoconductor and controlling the temperature to an appropriate level in order to reduce the negative effects on images caused by changes in environmental conditions. (See Canon JP-A-56-54474, JP-A-57-86877, and JP-A-60-129772).

However, when using a temperature control mechanism in a small copying machine or printer, it is difficult to install a heating mechanism due to the high cost and difficulty in securing space for installing the mechanism. Countermeasures are not yet being taken.

Therefore, in a low-cost, small-sized copier or printer,
The situation is that images are still being negatively affected by changes in environmental conditions.

On the other hand, metal-containing phthalocyanines or metal-free phthalocyanines such as aluminum chlorophthalocyanine, chloroindium phthalocyanine, vanadyl phthalocyanine, chlorogallium phthalocyanine, magnesium phthalocyanine, and oxotitanium phthalocyanine have recently been developed as charge-generating materials with high sensitivity to long wavelength light. Many studies have been conducted using . As an example, the following literature can be mentioned.

JP-A-52-105828, JP-A-53-203
34, JP-A-54-85032, JP-A-59-226351, etc.

[Problems to be Solved by the Invention] An object of the present invention is to provide a high-sensitivity electrophotographic photoreceptor containing a phthalocyanine pigment in its photoconductive layer, which is unlikely to cause deterioration of image quality due to changes in environmental conditions, and the like. An object of the present invention is to provide an electrophotographic method using a photoreceptor.

[Means for Solving the Problems] The present invention comprises, in an electrophotographic photoreceptor containing a phthalocyanine pigment in a photoconductive layer, a fluorine-based surfactant newly contained in the photoconductive layer.

Examples of the phthalocyanine pigment used in the present invention include metal-based phthalocyanines or metal-free phthalocyanines such as copper phthalocyanine, aluminum chlorophthalocyanine, and oxotitanium phthalocyanine, as well as halogen-substituted products thereof, including oxotitanium (also known as titanyl) phthalocyanine. is preferred.

Furthermore, examples of the fluorine-containing surfactant used in the present invention include fluorine-containing block copolymers and fluorine-containing graft copolymers. The amount of the fluorosurfactant added is set to be 0.5 to 60% by weight, preferably 5 to 40% by weight, based on 100% by weight of the phthalocyanine pigment.

If the amount of fluorine-based surfactant added is too small, the water repellent effect will be insufficient, and if it is too large, the residual potential will increase unreasonably. A fluorosurfactant may also be added to the charge transport layer of the photoreceptor.

The amount of the fluorosurfactant added to the charge transport layer is 0.5 to 60% by weight, preferably 5 to 40% by weight, based on the sum of the charge transport material and the solid content of the binder resin constituting the layer. It is set to be % by weight. If the amount of the fluorine-containing surfactant added is too small, a sufficient water repellent effect cannot be obtained, whereas if it is too large, there will be problems such as a decrease in sensitivity or a decrease in the film-forming properties of the photosensitive layer.

The method for producing the above-mentioned oxotitanium phthalocyanine which is most suitable for forming the photosensitive layer of the present invention will be exemplified below.

First, for example, titanium tetrachloride and orthophthalodinitrile are reacted in α-chlornaphthalene to obtain dichlorotitanium phthalocyanine. This is washed with a solvent such as α-chloronaphthalene, trichlorobenzene, dichlorobenzene, N-methylpyrrolidone or N,N-dimethylformamide, then washed with a solvent such as methanol or ethanol, and then hydrolyzed with hot water. Oxotitanium phthalocyanine crystals are obtained. Since the crystals thus obtained are often a mixture of various polymorphs, they are converted into amorphous oxotitanium by treatment with an acid pasting method.

Next, this amorphous oxotitanium phthalocyanine was added to 4
The above-mentioned oxotitanium phthalocyanine crystals are obtained by milling at 0 to 200°C, preferably 60 to 120°C, and further adding a solvent such as cyclohexanone and treating for 5 minutes to 24 hours, preferably 15 minutes to 10 hours.

Hereinafter, the typical M configuration of the electrophotographic photoreceptor of the present invention will be explained as follows.
This will be explained based on the drawings and FIG.

FIG. 1 shows a photosensitive layer 4 containing oxotitanium phthalocyanine crystals 2 provided on a conductive support 1 as a charge generation layer, and a photosensitive layer 5 containing a charge transporting material (not shown).
This shows a photoreceptor having a laminated structure of a so-called charge generation layer and a charge transport layer, which is provided as a charge transport layer. Note that in this case, the stacking order of the charge generation layer and the charge transport layer may be reversed.

FIG. 2 shows a photoreceptor in which the photosensitive layer 4 containing oxotitanium phthalocyanine crystals 2 is a single layer, and this photosensitive layer 4 simultaneously contains the oxotitanium phthalocyanine crystals 2 and a charge transport material (not shown). .

When producing the electrophotographic photoreceptor of the present invention, the conductive support 1 may be any material having conductivity (metal such as aluminum, corrosion-resistant steel (stainless steel), plastic with a conductive layer, paper, etc.). etc., and examples of the shape include a cylindrical shape or a film shape.

Further, a subbing layer having both a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer.

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

These are usually dissolved in a suitable solvent and applied onto a conductive support. The film thickness is usually 0.2 to 3.0 μm.

As a method for forming a charge generation layer consisting of a photosensitive layer with a laminated structure as shown in FIG. An example of this would be to apply a dispersion of the liquid to a substrate and then dry it.

Examples of the binder resin used here include polyester resin, acrylic resin, polyvinyl carbazole resin, phenoxy resin, polycarbonate resin, polyvinyl butyral resin, polystyrene resin,
The main ones include polyvinyl acetate resin, polysulfone resin, polyarylate resin, and vinylidene chloride/acrylonitrile copolymer resin.

The charge transport layer is mainly formed by coating a paint (coating liquid) in which a charge transport material and a binder resin are dissolved or dispersed in a solvent and then drying the paint.

When forming a photosensitive layer consisting of a single layer as shown in Fig. 2, a paint made by mixing oxotitanium phthalocyanine crystals, a fluorine-based surfactant, and a charge transport material in a solution of a suitable binder resin is applied and dried. You can get it.

Examples of the charge transport material used include various triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds.

Furthermore, as the binder resin, those used for creating the above-mentioned charge generation layer can also be used.

Coating methods for these photosensitive layers include dipping,
Spray coating method, spinner coating method,
Examples include bead coating method, plate coating method, and beam coating method.

When the photosensitive layer is a single layer, the film thickness is usually 5 to 40μ.
m, preferably 10 to 30 μm.

In addition, when the photosensitive layer has a laminated structure, the thickness of the charge generation layer is usually 0.01 to 10 μm, preferably 0.05 to 5 μm.
m, and the thickness of the charge transport layer is usually set to 5 to 40 μm, preferably 10 to 30 μm.

Note that when oxotitanium phthalocyanine crystal is used as a charge-generating material, it can also be used in combination with other charge-generating materials depending on the purpose.

The electrophotographic photoreceptor of the present invention can be used in a laser beam printer,
It can be widely applied not only to printers such as LED printers and CRT printers, but also to ordinary electrophotographic copying machines and other electrophotographic application fields, such as the facsimile field.

FIG. 3 shows a schematic configuration of a general transfer based electrophotographic apparatus using the drum type photoreceptor of the present invention.

In FIG. 3, reference numeral 6 denotes a drum-type photoreceptor as an image carrier, which is rotated at a predetermined circumferential speed in the direction of the arrow around a shaft 6a. The photoreceptor 6 is charged by charging means 7 during its rotation process.
As a result, the peripheral surface thereof is uniformly charged with a predetermined positive or negative potential, and then, in the exposure section 8, it is subjected to optical image exposure L (slit exposure, laser beam scanning exposure, etc.) by an image exposure means (not shown). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the circumferential surface of the photoreceptor.

The electrostatic latent image is then developed with toner by a developing means 9, and the toner developed image is transferred from a paper feed section (not shown) between the photoreceptor 6 and the transfer means 10 by a transfer means 10 in synchronization with the rotation of the photoreceptor 6. The images are sequentially transferred onto the surface of the transfer material P that has been taken and fed.

The transfer material P that has undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 13, where the image is fixed, and printed out outside the machine as a copy.

After the image has been transferred, the surface of the photoreceptor 6 is cleaned by a cleaning means 11 to remove residual toner and is repeatedly used for image formation.

As the uniform charging means 7 for the photoreceptor 6, a corona charging device is generally widely used. Further, as the transfer device 10, corona transfer means is widely and generally used. As an electrophotographic apparatus, a plurality of components such as the above-mentioned photoreceptor, developing means, cleaning means, etc. are integrated and combined as an apparatus unit, and this unit is configured to be detachable from the apparatus main body. You may do so. For example, the photoreceptor 6 and the cleaning means 11 may be integrated into a single apparatus unit, and may be configured to be detachable using a guide means such as a rail of the apparatus main body. In this case, the above-mentioned device unit may include a charging means and/or a developing means.

In addition, when an electrophotographic device that exposes a light image is used as a copying machine or a printer, the reflected light from the original, the transmitted light, or the original is read and converted into a signal, and this signal is used to scan the laser beam and drive the light emitting diode array. Alternatively, this may be performed by driving a liquid crystal shutter array or the like.

Furthermore, when used as a facsimile printer, the optical image exposure is exposure for printing received data. FIG. 4 is a block diagram showing an example of this case.

In FIG. 4, the controller 15 is the image reading section 1.
4 and printer 23. The entire controller 15 is controlled by the CPU 21. The read data from the image reading section is transmitted to the other station through the transmitting circuit 17.

Data received from the partner station is sent to the printer 23 through the receiving circuit 16. Image memory 20 stores predetermined image data. A printer controller 22 controls a printer 23. 18 is a telephone.

Images received from the line 19 (image information from a remote terminal connected via the line) are demodulated by the receiving circuit 16, and then decoded by the CPU 21 and sequentially stored in the image memory 20. Ru. Then, when at least one page worth of images is stored in the image memory 20, the image recording of that page is performed. The CPU 21 reads out one page of image information from the image memory 20 and sends the decoded one page of image information to the printer controller 22 . When the printer controller 22 receives one page of image information from the CPU 21, it controls the printer 23 to record the image information of that page. Note that the CPU 21 is receiving the next page while the printer 23 is recording.

As described above, images are received and recorded.

Example 1 Aluminum cylinder (outer diameter 30mm x length 260m)
m) Apply a solution of 5 parts by weight of quaternary (6-66-610-12) polyamide copolymer resin dissolved in a mixed solvent of 70 parts by weight of methanol and 25 parts by weight of butanol onto the surface by dipping, and then dry. Then, a subbing layer having a film thickness of 1 μm was provided.

Next, 4 parts by weight of oxotitanium phthalocyanine crystals, 2 parts by weight of polyvinyl butyral resin, and 100 parts by weight of cyclohexanone were added and mixed and dispersed for 2 hours in a sand mill using glass beads having a diameter of 1 mm. 100 for this
Fluorine surfactant dissolved in parts by weight of methyl ethyl ketone [Product name: Modivar F100 (manufactured by NOF ■)
]11 weight was added and diluted, recovered, and coated on the undercoat layer. Next, it was dried at 80° C. for 10 minutes to form a charge generation layer with a thickness of 0.15 μm.

Next, 10 parts by weight of a charge transport material shown by the following structural formula and bisphenol 2
A solution was prepared by dissolving 10 parts by weight of a type polycarbonate resin in 60 parts by weight of monochlorobenzene, and the solution was applied onto the charge generation layer by a dipping method. This was dried at a temperature of 110° C. for 1 hour to form a charge transport layer with a thickness of 20 μm, thereby producing an electrophotographic photoreceptor.

The sensitivity and image evaluation results are shown in Table 1.

Example 2 In Example 1, a fluorine-based surfactant [(trade name: MODIPER F100) (manufactured by NOF ■) 1 was added to the charge transport layer.
An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that 2 parts by weight of the compound was dissolved in 10 parts by weight of dichloroethane and added. The sensitivity and image evaluation results are shown in Table 1.

Example 3 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the amount of the fluorine-based surfactant used in Example 1 was changed to 1.6 parts by weight. The sensitivity and image evaluation results are shown in Table 1.

Example 4 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the amount of the fluorine-based surfactant used in Example 1 was changed to 0.2 parts by weight. The sensitivity and image evaluation results are shown in Table 1.

Comparative Example 1 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the fluorine-based surfactant used in Example 1 was not added. The sensitivity and image evaluation results are shown in Table 1.

Comparative Example 2 An electrophotographic photoreceptor was produced in the same manner as in Example 2, except that the fluorine-based surfactant added to the charge generation layer in Example 2 was not added. The sensitivity and image evaluation results are shown in Table 1.

Each photoconductor in Examples 1 to 4 and Comparative Examples 1 to 3 was printed using a laser beam printer [Product name: LBP-3
X (manufactured by Canon)] and set the dark potential to -700V.
After setting the charge to 1, it was irradiated with a laser beam having a wavelength of 802 nm, and the amount of light required to attenuate the potential from 1,700 V to 1,500 V was measured and used as the sensitivity. The results are shown in Table 1.

Next, a continuous paper feeding durability test of 4,000 sheets was conducted with each of the photoreceptors in Examples 1 to 4 and Comparative Examples 1 to 3 set to a dark area potential of -700V and a light area potential of -150V. The test environment was set at a high temperature of 30° C. and 85% RH, and images were evaluated. The results are also shown in Table 1.

Table 1: μJ/cm2: Good: Spicy (Can be used: Cannot be used on the side bottom [Effects of the Invention] The electrophotographic photoreceptor of the present invention is formed by dispersing a phthalocyanine pigment in a binder resin, and its photoconductive layer Since it further contains a fluorine compound, it stably exhibits excellent characteristics even in high-temperature environments, and there is almost no deterioration in image quality due to long-term use (and high sensitivity can be maintained).

[Brief explanation of drawings]

1 and 2 are schematic cross-sectional views showing the typical layer structure of the electrophotographic photoreceptor of the present invention, FIG. 3 is a schematic configuration diagram of a general transfer type electrophotographic device, and FIG. 4 is an electronic FIG. 2 is a block diagram of a facsimile system using a photographic device as a printer. 1... Conductive support 2... Oxotitanium phthalocyanine crystal 3...
Block copolymer or graft copolymer of a fluorine-based compound 4...Photosensitive layer 5 containing oxotitanium phthalocyanine crystals...Photosensitive layer 6 containing a charge transporting material...Drum-shaped photoreceptor 14...Image reading section 15 ... Controller 16 ... Receiving circuit 17 ... Transmitting circuit 18 ... Telephone 19 ... Turning spring 20 ... CPU 22 ... Printer controller 23 ... Printer

Claims (7)

[Claims] (1) In an electrophotographic photoreceptor in which a photoconductive layer in which a phthalocyanine pigment is dispersed in a binder resin is formed on a conductive support, the fluorine-based compound in the photoconductive layer is based on 100% by weight of the phthalocyanine pigment. An electrophotographic photoreceptor characterized in that the content is 0.5 to 60% by weight. (2) The electrophotographic photoreceptor according to claim 1, wherein the fluorine-based compound is one or more selected from fluorine-containing block copolymers and fluorine-containing graft copolymers. (3) The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is a laminate of a charge-generating layer and a charge-transporting layer comprising a photoconductive layer containing a fluorine-based compound. (4) In the laminated electrophotographic photoreceptor, the fluorine compound in the charge transport layer is 0.5 to 6% by weight based on 100% by weight of the charge transport substance and binder resin in the layer.
The electrophotographic photoreceptor according to claim 1, characterized in that the content is 0% by weight. (5) The electrophotographic photoreceptor according to claim 1, wherein the phthalocyanine pigment is oxotitane phthalocyanine. (6) A facsimile machine comprising an electrophotographic apparatus including the electrophotographic photoreceptor according to any one of claims 1 to 5 and a receiving means for receiving image information from a remote terminal. (7) An electrophotographic method for forming an image on a photoreceptor through a process consisting of charging, exposure, and development, which is characterized by using a reversal development method in which a toner image is formed on the exposed area. .