JPH0217026B2 - - Google Patents

Description

[Detailed description of the invention]

1. Field of Industrial Application The present invention relates to an image carrier in a recording device, such as a photoreceptor for electrophotography or electrostatic recording. 2. Prior Art Conventionally, in recording devices such as electrostatic recording and electrophotography, an electrostatic charge image is formed on an image bearing member such as a photoreceptor drum, and this is converted into a developer mixed with toner and, if necessary, carrier. An image is formed based on the process of developing the toner image, transferring the resulting toner image onto a transfer sheet, and further fixing it. However, drawbacks of the conventional apparatus include that the apparatus itself is heavy and the manufacturing cost is high, especially since the base of the image bearing member such as the photosensitive drum is made of metal, for example, aluminum. In addition, when forming an organic optical semiconductor layer as a photosensitive layer on the surface of a substrate of an image carrier, the substrate does not have sufficient chemical resistance to solvents. 3. Purpose of the Invention It is an object of the present invention to provide an image carrier having a substrate with excellent chemical resistance, heat resistance, mechanical strength, etc. while reducing the weight and cost of a recording device. . 4. Structure of the Invention That is, the present invention provides an image carrier in a recording device, characterized in that the base is formed of a material whose main component is polyphenylene sulfide (hereinafter abbreviated as PPS). , for example, relates to a photoreceptor drum. 5 Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows an electrophotographic copying machine having a roll-shaped intermediate transfer member. Around the photosensitive drum 1 as an image carrier having a photosensitive layer made of selenium, an organic photoconductive substance, etc., there is an electrostatic latent image forming section 2 containing a known corona charger and exposure system, and a developing sleeve 3a. A developing unit 3 is disposed for sending conductive magnetic toner 3b to the photosensitive drum 1 while being set up by a magnet therein and having its thickness regulated by a thickness regulating plate 3c. Since a reverse charge is induced in the toner by the electrostatic latent image on the drum 1,
The toner particles are sequentially moved onto the drum 1 in proportion to the charge weight of the electrostatic latent image and are attracted thereto, forming a toner image of a predetermined pattern thereon, and development is performed. This toner image is then pressed onto an intermediate transfer roll 35 that is pressed against the drum 1 at a predetermined pressure (approximately 0.5 kg/cm or less). The toner image transferred onto the intermediate transfer roll 35 is then sent from the pressure transfer unit 6 to the transfer fixing unit 12 while being held on the roll 35. The toner image is preheated by a heater 30 before the transfer fixing section 12 and transferred to the roll 3.
5, it is in a state where it is easy to peel off again. Instead of the heater 30, a heater lamp (not shown) built into the roll 35 may be used as a preheating means. In the transfer fixing section 12, a pressure roll 14 containing a heater lamp (not shown) is pressed from below, and a copy paper 15 is passed between the intermediate transfer roll 35 and the pressure roll 14 in this pressure area. By doing so, the toner particles on the roll 35 are transferred onto the copy paper 15 while heating the paper, and are fixed at the same time. After the above-described pressure transfer, residual toner on the photosensitive drum 1 is removed by a cleaning device 18, and residual charges are further removed by a static eliminator 19 including a static eliminator lamp or the like. A noteworthy feature of the copying machine configured as described above is that the photosensitive drum 1, which is an image carrier,
As shown in FIG. 2, it has a drum substrate 4 whose main component is PPS, and a photosensitive layer (photoconductive layer) 5 is provided thereon. PPS as a substrate material

A polymer consisting of a structural unit represented by [Formula],
It exhibits the following excellent properties. (1) Excellent heat resistance Since it exhibits a continuous heat resistance temperature of 220 to 240°C, in the above intermediate transfer method, a heater is built into the roll 35 to preheat the toner image on the roll 35. Even in this case, the photoreceptor drum 1 has sufficient heat resistance. (2) Good chemical resistance Since PPS has excellent chemical resistance comparable to that of fluororesins, when forming an organic optical semiconductor layer as the photosensitive layer 5, it is difficult to use the solvent. The substrate 4 does not swell or the like. (3) The device can be made lighter. Compared to conventional metal drum substrates, PPS is lighter, so the weight of the drum itself and, by extension, the weight of the copying machine can be reduced. (4) High strength and rigidity PPS has little change in strength and rigidity even at high temperatures, and also has little creep deformation, so it is suitable as a photoreceptor substrate material in the transfer method shown in FIG. (5) Good dimensional stability Dimensional changes are small even in high temperature atmosphere over a long period of time. (6) Flame retardant Passes the flame retardant standard (UL94V-O) without adding flame retardants. (7) Good electrical properties PPS has excellent electrical insulation properties, and can also be made electrically conductive by incorporating carbon, etc. (8) Good injection moldability PPS has good fluidity and can be molded in the same way as general engineering plastics (melting temperature is, for example, 300°C), making it possible to reduce the manufacturing cost of molded products. It is. Usable PPS include EXP type, CZ type (carbon fiber reinforced conductive PPS), FZ type (glass fiber reinforced type), Ryton (glass fiber reinforced type) manufactured by Dainippon Ink & Chemicals Co., Ltd. Specifically, there are the following. EXP8-2 EXP9-3 EXP08 (contains conductive carbon black) CZ-1130 (30% carbon fiber) FCZ-1230 CZL-4033 (carbon fiber/fluororesin reinforced product) FZ-1140 (40% glass fiber) FZ- 3360 (glass fiber and inorganic filler reinforced type) FZL-4033 (glass fiber/fluororesin reinforced product) Ryton R-3, R-4, R-5 (all glass fiber 30-45%) Ryton R-9 Ryton R-10 7006A, R-10 5002C, R-
10 7007A, R-10 5004A (both glass fiber/inorganic filler reinforced products) Next, the characteristic values of some of the above PPS will be shown.

[Table] As shown above, PPS used as a substrate material has sufficient strength and heat resistance, has a low specific gravity, and can also exhibit electrical conductivity depending on additives. If conductive PPS is used, it is possible to use a photoreceptor having the structure shown in FIG. 2, but in the case of non-conductive PPS, a conductive layer (for example, It is necessary to interpose a metal film). In this sense,
It is desirable that the volume resistivity of the PPS substrate is 10 ⁹ Ω-cm or less. Further, when the above conductive layer is applied, its volume resistivity is preferably 10 ³ Ω-cm or less. FIG. 3 shows an example of an ordinary type electrophotographic copying machine incorporating a photosensitive drum 9 having a PPS substrate. In this copying machine, at the top of the cabinet 1, there is a glass document mounting table 43 on which a document 42 is placed.
and a platen cover 44 that covers the document 42. Below the document table 43, an optical scanning table consisting of a first mirror unit 47 equipped with a light source 45 and a first reflection mirror 46 is provided so as to be movable linearly in the left and right direction of the drawing, and is arranged to align the document scanning point with the photoreceptor. A second mirror unit 20 for making the optical path length constant moves according to the speed of the first mirror unit, and the reflected light from the document table 3 passes through the lens 21 and the reflection mirror 8 and is reflected as an image carrier. The light is incident on the photosensitive drum 9 in a slit shape. Around the drum 9, a corona charger 10, a developing device 11, a transfer section 52, a separating section 53, and a cleaning section 54 are arranged, respectively. After the toner image is transferred from the drum 9, the paper 58 is further fixed in a fixing section 59, and then discharged onto the tray 35. In the fixing section 59, the developed copy paper is passed between a heating roller 23 having a built-in heater 22 and a pressure roller 24 to perform a fixing operation. FIG. 4 shows a copying machine having the photosensitive drum 1 shown in FIG. 1 and directly thermally transferring a toner image onto copy paper 15 from the photosensitive drum 1. The pressure roller indicated by 14 in the figure has a built-in heater, and its surface temperature is set at 160 to 200 DEG C., which is sufficient for transferring and fixing the toner image. Here again, since the substrate of the photoreceptor 1 is made of the above-mentioned PPS, it has sufficient heat resistance, strength, etc. even when the heat roll 14 is pressed against the photoreceptor drum 1. Since the photosensitive drum 1 is heated by the roll 14 (or 35), in order to prevent the characteristics of the photosensitive layer on its surface from deteriorating due to heat, the photosensitive drum 1 is heated as shown in FIG. It is preferable that heat dissipation fins 50 are integrally provided on the inner surface of one of the substrates, and the inside of the drum is configured so that hot air can be exhausted.
This heat dissipation fin 50 can be integrally molded with the same PPS as the substrate. Due to the presence of the heat dissipation fins 50, the temperature of the photosensitive layer can always be maintained at a desired temperature (for example, about 50° C.; in the case of an organic optical semiconductor, up to about 80° C. is allowed). Next, the present invention will be explained in detail using more specific examples. (Example 1) Commercially available PPS (CZ-1130) shown in the table above was injection molded into a drum shape. Next, a vinyl chloride-vinyl acetate-maleic anhydride copolymer (Eslec MA, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in cyclohexanone and coated on the injection molded drum to form an intermediate layer with a dry film thickness of 0.7 μm. Established. Next, polycarbonate resin (Panlite L
-1250, manufactured by Teijin Kasei Ltd.), was dissolved in 1,2-dichloroethane, and in this solution was added a carrier generating substance (Anthorone pigment Monolight Red 2γ, (I.
A dispersion obtained by ultrasonically dispersing No. 59300)) was coated on the intermediate layer to form a carrier generation layer with a dry film thickness of 2 μm. Next, the polycarbonate resin and the carrier transport material (1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)n-butane) are dissolved in 1,2-dichloroethane, and this solution is added to the Coated on top of carrier generation layer, dry film thickness 18μm
A carrier transport layer was provided to obtain an electrophotographic photoreceptor according to the present invention. (Sample-1) (Example 2) Conductive carbon black (Ketsuchen Black EC,
(manufactured by Nippon EC Co., Ltd.) in a ratio of 100/40,
Injection molded into a drum shape with a volume resistivity of 10 ³ Ω
-cm resin drum was obtained. Next, an electrophotographic photoreceptor according to the present invention was obtained in the same manner as in Example-1. (Sample-2) (Example 3) An electrophotographic photoreceptor was obtained in the same manner as in Example-2 except that PPS was replaced with another commercially available PPS (Ryton R-4). (Sample-3) (Comparative Example 1) Injection molded into a drum shape using commercially available phenolic resin (Exelite, manufactured by Tokai Rubber Industries, Ltd.),
A resin drum with a volume resistivity of 10 ³ Ω-cm was obtained.
Next, a comparative electrophotographic photoreceptor was obtained in the same manner as in Example-1. (Sample-4) (Comparative Example 2) Commercially available ABS resin (Kane Ace MUH, S-
2020, manufactured by Kanebuchi Kagaku Kogyo Co., Ltd.) and conductive carbon black (Ketsutchen Black EC, manufactured by Nippon EC Co., Ltd.) at a ratio of 100:40, injection molded into a drum shape with a volume resistivity of 10 ³ Ω. A resin drum of cm was obtained. Next, a comparative electrophotographic photoreceptor was obtained in the same manner as in Example-1. (Sample-5) Regarding (Sample-1) to (Sample-5), the degree of elution from the resin drum during coating through the intermediate layer, carrier generation layer, and carrier transport layer (Table 2)
Table 3 shows a comparison of the surface roughness before coating and after coating. Separately, (Sample-1) to (Sample-5) were installed in the apparatus shown in the example of FIG. 4, and a test was repeated 5,000 times. The results are shown in (Table 4).

【table】

【table】

[Table] As can be seen from the results of (Table-2) and (Table-3),
Many resins such as ABS resin lack chemical resistance to organic solvents, such as halogenated solvents, used when coating carrier generation layers and carrier transport layers. Swelling and elution occur, resulting in roughened drum surface.
Large irregularities occur, making it unsuitable as a photoreceptor. However, since most PPS resins exhibit extremely high chemical resistance to organic solvents, they are not limited by the solvent during coating, allowing a wide range of choices. On the other hand, even if the resin has excellent chemical resistance,
As can be seen from the results in Table 4, high heat resistance (thermal shock resistance, thermal fatigue resistance, etc.) is particularly required in the process using the apparatus shown in FIG. In addition to this, moldability is actually required when making drums, and these characteristics have not been easily satisfied with conventional resins. However, by using PPS resin, it was possible to obtain a photoreceptor that satisfied these characteristics. Although the present invention has been illustrated above, the above-mentioned example can be further modified based on the technical idea of the present invention. For example, the constituent material of the substrate may be made of only PPS, or may be made of PPS plus additives as described above. In the present invention, the above-mentioned "main component" means
Also includes 100% PPS. 6 Effects of the Invention As described above, the present invention uses PPS as the base of the image carrier.
Because it is made of a material whose main component is PPS, the base material has excellent heat resistance, strength, and
It has significant advantages in terms of light weight, chemical resistance, etc. that cannot be achieved with conventional metal substrates.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram of the main parts of an intermediate transfer type copying machine, and FIG.
3 is a schematic sectional view of a copying machine according to another example, FIG. 4 is a schematic diagram of main parts of a copying machine according to another example, and FIG. 5 is a sectional view of another photoconductor drum. FIG. In addition, in the symbols shown in the drawings, 1, 9...
... Photosensitive drum, 4 ... Drum substrate, 5 ... Photosensitive layer, 14 ... Heat roll, 15, 58 ... Copy paper,
35... Intermediate transfer roll.

Claims (1)

[Scope of Claims] 1. An image carrier in a recording device, characterized in that the base is formed of a material containing polyphenylene sulfide as a main component. 2. The image carrier according to claim 1, wherein the polyphenylene sulfide layer of the substrate contains glass fibers. 3 The first claim of claim 1, wherein carbon fiber is contained in the polyphenylene sulfide layer of the base body.
The image carrier described in section. 4. The image carrier according to claim 1, wherein the polyphenylene sulfide layer of the substrate contains conductive carbon black. 5 The volume resistivity of the base is 10 ⁹ Ω-cm or less,
An image carrier according to any one of claims 1 to 4. 6. The image carrier according to any one of claims 1 to 5, wherein a conductive layer having a volume resistivity of 10 ³ Ω-cm or less is provided on a substrate. 7. The image carrier according to any one of claims 1 to 6, wherein the toner image formed on the surface is directly thermally transferred to a transfer material. 8. According to any one of claims 1 to 6, the toner image formed on the surface is indirectly thermally transferred to the transfer material via an intermediate transfer member. image carrier.