JP2005227703A - Method for peeling photosensitive layer of electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To peel a photosensitive layer in a short time into a clean state when a photosensitive layer on the surface of an electrophotographic photoreceptor is to be peeled so that no scratch remains on a conductive supporting body after the photoreceptor is removed so as to effectively reuse the supporting body and that the supporting body after the photosensitive layer is peeled can be smoothly processed. <P>SOLUTION: Dry ice particles 18 are sprayed by compressed air in a spray amount of 0.5 to 2 kg/min to the electrophotographic photoreceptor 10 having a photosensitive layer 12 on the surface of a conductive supporting body at a pressure on the photoreceptor 10 in the range of 0.1 to 1.0 MPa so as to peel the photosensitive layer 12 from the surface of the conductive supporting body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member used in an electrophotographic apparatus such as a copying machine or a printer, and more particularly to a method for removing a photosensitive layer forming a surface of the electrophotographic photosensitive member.

  In the electrophotographic photoreceptor, a photosensitive layer is formed on the surface of a conductive support such as an aluminum tube using an inorganic material centering on selenium or a selenium alloy, or a phthalocyanine-based or azo-based organic material. For defective products in the manufacturing process that occur when forming a photosensitive layer on the surface of a conductive support and used recovered products collected from the market, the photosensitive layer is peeled off from the surface of the conductive support. A method has been adopted in which a photosensitive layer is formed again on the surface of the conductive support after being collected and peeled and reused as an electrophotographic photosensitive member.

  Conventionally, for example, a method described in Patent Document 1 is known as a method of peeling a photosensitive layer from the surface of a conductive support. This method is mainly used to peel off a photosensitive layer made of organic material. The electrophotographic photosensitive member is immersed in a reaction tank containing concentrated nitric acid to oxidize and decompose the photosensitive layer. The photosensitive layer is peeled off from the surface of the support. In addition, as a method for peeling off a photosensitive layer made of an inorganic material, for example, a method in which a shot material such as glass beads or resin beads is made to collide with the surface of an electronic resin photoreceptor and the photosensitive layer is peeled off by abrasion with the shot material. It has been.

  However, in the above conventional peeling method, in the former case, it is necessary to immerse the reaction tank containing concentrated nitric acid many times and repeatedly in order to completely peel the photosensitive layer. In addition to the fact that it took time to peel off, there was a problem that was not suitable for practical use, and there was also a problem in terms of disposal of concentrated nitric acid.

  On the other hand, in the latter case, after removing the photosensitive layer, it is necessary to clean the surface of the conductive support to remove the residue of the beads, and when collecting the peeled photosensitive layer, the beads are separated from the beads. In addition to the need for a process, the surface of a conductive support such as an aluminum tube may be damaged by the impact of a bead collision and cannot be effectively reused.

JP 63-261367 A

  SUMMARY OF THE INVENTION Therefore, a first object of the present invention is to make it possible to completely peel and remove the photosensitive layer from the surface of the conductive support in a short time. Secondly, the surface of the conductive support after the photosensitive layer is peeled and removed can be effectively reused without leaving any scratches. Thirdly, the processing after the photosensitive layer is peeled off can be performed promptly.

  As a result of intensive studies to solve the above problems, the present inventors have found that a method of spraying dry ice particles on the surface of an electrophotographic photosensitive member and causing them to collide and peeling by impact at that time is effective. I found it. Specifically, the method for peeling off a photosensitive layer of an electrophotographic photosensitive member according to the present invention sprays dry ice particles sprayed with compressed air onto an electrophotographic photosensitive member having a photosensitive layer formed on the surface of a conductive support. The photosensitive layer is peeled off from the surface of the conductive support.

  The photosensitive layer peeling method of the present invention in which dry ice particles are sprayed is effective regardless of whether the photosensitive layer is an inorganic material or an organic material.

Further, when the dry ice particles are in the form of pellets or powder, effective peeling can be expected and handling of the dry ice particles is facilitated. In order to more effectively peel the photosensitive layer, the spray amount of the dry ice particles is in the range of 0.5 to 2 kg / min, and the pressure applied to the electrophotographic photosensitive member by the dry ice particles is 0.1 to 1.0 MPa ( It is desirable that the electrophotographic photosensitive member for the dry ice particles be subjected to a range of 0.5 to 5.0 sec / cm ² in the range of “mechanical skull”.

  In the photosensitive layer peeling method of the present invention, when the electrophotographic photosensitive member is constituted by a drum, the dry ice particles are sprayed while moving the drum along the rotation center axis of the drum while rotating the drum. Dry ice particles can be sprayed uniformly on the surface.

  As described above, according to the photosensitive layer peeling method of the electrophotographic photosensitive member according to the present invention, it is not necessary to clean the surface of the conductive support after peeling the photosensitive layer by using dry ice particles. The photosensitive layer can be completely peeled and removed from the surface of the conductive support in a short time.

  Further, according to the method for peeling off the photosensitive layer of the electrophotographic photosensitive member according to the present invention, the surface of the conductive support is not damaged by utilizing thermal shock with the peeled surface together with the impact force of dry ice particles. Thus, the photosensitive layer can be peeled off.

  Furthermore, according to the photosensitive layer peeling method of the electrophotographic photoreceptor according to the present invention, dry ice particles are sublimated (gasified) at the same time as they collide with the surface to be peeled. In other words, it does not remain in the processing apparatus and does not need to be recovered, so that the processing after the photosensitive layer is peeled off can be performed quickly. Moreover, since dry ice particles are non-toxic and nonflammable, they have high practical value.

Hereinafter, preferred embodiments of the electrophotographic photosensitive member according to the present invention will be described in detail.
The dry ice particles in the present invention are preferably pellet-shaped dry ice particles 1 as shown in FIG. This is because the impact force due to the collision is obtained, and at the same time, the sublimation is fast and the handling is easy. The size of the pellet is not particularly limited, but for the above purpose, the length dimension L is preferably 10 mm or less and the width dimension W is preferably 5 mm or less. Further, preferably L = 2 to 4 mm and W = 2 to 3 mm. The dry ice particles are not limited to the above-described pellet shape, and powdered particles are also advantageous in terms of sublimation and handling. The impact force due to the collision can be adjusted by the spray amount and spray pressure of dry ice particles described later. It does not matter so much whether the specific shape in the form of powder is close to a sphere or close to a needle shape. The average particle size when powdered is preferably 1 mm or less. However, it goes without saying that the shape, size, particle size and the like of the dry ice particles can be appropriately selected depending on the material and thickness of the conductive support and the photosensitive layer. In addition, the dry ice particle can utilize what is generally marketed for cooling. Therefore, dry ice particles can be produced by a known method.

In the photosensitive layer peeling method of the present invention, it is effective to spray the dry ice particles from the spray nozzle with compressed air. It is necessary to appropriately control the spray amount and spray pressure of dry ice particles during spraying according to the material of the conductive support, the material of the photosensitive layer, the film thickness, and the like. It is necessary to set in advance a range in which the photosensitive layer can be completely peeled and removed in a short time and at the same time the surface of the conductive support is not damaged. At that time, it is desirable to control the injection distance and the like. As an example, considering the case where the conductive support is an aluminum tube and the photosensitive layer is made of a selenium alloy, the dry ice particle injection amount is in the range of 0.5 to 2 kg / min, and the dry ice particle electrophotographic photosensitive member is used. The pressure received by the body is selected in the range of 0.1 to 1.0 MPa (mechanical skull), and the time that the electrophotographic photosensitive member of the dry ice particles receives is selected in the range of 0.5 to 5.0 sec / cm ^2. It is desirable. If the injection amount or the injection pressure is small or the injection time is short, the photosensitive layer cannot be completely removed in a short time. Conversely, if the injection amount or the injection pressure is too large or the injection time is long, the conductive support. There is a risk of damaging the surface. For the spraying of the dry ice particles, a commercially available general spraying device can be used.

  As a material for the conductive support to which the present invention is applied, a single metal such as brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, indium, etc. in addition to the above aluminum And its alloys. In addition, conductive materials such as the above metals and carbon that are made conductive by vapor deposition or plating on plastic materials, and conductive glass coated with tin oxide, indium oxide, aluminum iodide, etc. are also applicable. The Further, the shape of the conductive support is not limited to the cylindrical drum, but can be applied to rods, plates, sheets, belts, and the like.

  As an aluminum alloy used as the material of the conductive support, for example, JIS 3000 series, JIS 5000 series, and JIS 6000 series can be used. These aluminum alloys are formed into a predetermined shape by a general method such as EI method, ED method, DI method, II method, etc., and then surface treatment such as surface cutting processing, polishing, anodizing treatment, etc. with a diamond tool, etc. Is applied to form a predetermined conductive support.

  Moreover, both an inorganic material and an organic material are applied to the photosensitive layer. Examples of the inorganic material include selenium, a selenium alloy, and amorphous silicon. Organic materials include various pigments such as disazo pigments and phthalocyanine pigments and charge generation materials such as dyes, charge transfer materials such as polyvinyl carbazole, hydrazone compounds and butadiene compounds, electron transfer materials such as diphenoquinone, and antioxidants. And additives such as sensitizers and sensitizers.

  As the means for forming the photosensitive layer, the above-mentioned photosensitive layer material is dispersed and dissolved in a binder resin, and then applied or vapor-deposited on the surface of a conductive support, or a CVD method (chemical vapor). (Deposition method) or the like. When the photosensitive layer is configured as a photosensitive layer of a laminated electrophotographic photosensitive member in which a charge generation layer and a charge transfer layer are laminated on a conductive support, the charge generation agent and the charge transfer agent are contained in the same layer. When configured as a photosensitive layer of a single-layer type electrophotographic photosensitive member, it may be applied as a photosensitive layer of an inversely laminated electrophotographic photosensitive member in which a charge generation layer and a charge transfer layer are sequentially stacked.

  The photosensitive layer may be formed not only directly on the surface of the conductive support but also through an intermediate layer provided between the conductive support and the photosensitive layer. By providing this intermediate layer, injection of free charge from the conductive support is prevented, and the adhesive strength between the conductive support and the photosensitive layer is improved, and in addition, a countermeasure effect against interference fringes is obtained. Examples of the intermediate layer include metal oxides such as aluminum oxide and titanium oxide, and insulating resins such as polyethylene, polyamide, polyimide, and polycarbonate. In addition, a material containing a conductive substance in the insulating resin, or a known material for an intermediate layer such as a conductive resin or a metal film can be used alone or in combination as appropriate. When an aluminum tube is used for the conductive support, it is possible to provide an alumite layer on the surface by anodizing. Furthermore, a protective layer may be provided on the photosensitive layer for the purpose of improving durability and the like. As the protective layer, polyvinyl formal, polycarbonate, silicon resin or the like is applied.

  Next, means for carrying out the photosensitive layer peeling method according to the present invention will be described with reference to FIGS. In the figure, reference numeral 10 denotes an electrophotographic photosensitive member, and a photosensitive layer 12 made of a selenium alloy is formed on the surface of a conductive support 11 formed of an aluminum tube. The electrophotographic photosensitive member 10 is rotatably supported on both sides by jigs 13 and 14. The ejection device 15 is disposed on one side of the electrophotographic photosensitive member 10, and dry ice particles 18 are ejected toward the electrophotographic photosensitive member 10 from an ejection nozzle 17 provided at the tip of a hose 16 extending from the ejection device 15. The The spraying of the dry ice particles 18 is performed for several seconds to several minutes. During this time, the spraying nozzle 17 moves along the length direction of the electrophotographic photosensitive member 10 that rotates together with the jigs 13 and 14. To do. Therefore, the dry ice particles 18 can collide uniformly over the entire circumferential surface of the electrophotographic photoreceptor 10.

  As shown in FIGS. 3A and 3B, the photosensitive layer 12 formed on the surface of the conductive support 11 has an impact when the dry ice particles 18 collide with the surface of the electrophotographic photoreceptor 10. Besides being peeled off by force, the dry ice particles 18 are sprayed at an extremely low temperature, so that a thermal shock is generated on the surface of the electrophotographic photosensitive member 10, which causes fine cracks on the surface of the photosensitive layer 12. Therefore, the photosensitive layer 12 can be effectively peeled off. Further, the dry ice particles 18 sublime at the same time as they collide with the surface of the electrophotographic photosensitive member 10, but the photosensitive layer 12 is also peeled off by the rapid volume expansion at that time.

  As described above, since the dry ice particles 18 are sublimated simultaneously with the collision and do not remain behind, the surface of the conductive support 11 is washed after peeling off the photosensitive layer 12 as in the prior art, and concentrated nitric acid or bead residue. Therefore, the photosensitive layer 12 can be completely peeled off from the surface of the conductive support 11 in a short time. Further, the conventional glass beads recovery process and concentrated nitric acid post-treatment process are not required. Furthermore, the oil or dust on the surface of the conductive support 11 is cooled and solidified by the low temperature effect of the dry ice particles 18, and the solidified oil or dust is blown away by the energy when the dry ice particles 18 sublimate. Also, there is an effect that oil and dust can be removed simultaneously with the peeling of the photosensitive layer 12.

  The surface of the electrophotographic photosensitive member 10 is cooled when the dry ice particles 18 are collided, and ambient air may appear as water droplets or condensation on the surface of the electrophotographic photosensitive member 10. In such a case, for example, an atmosphere control device is provided so that the surface of the electrophotographic photosensitive member 10 can be dried by placing a heat source on the jigs 13 and 14 to heat the electrophotographic photosensitive member 10 or can be peeled off in a certain atmosphere. Etc. may be provided to manage the surface temperature of the electrophotographic photosensitive member 10. It goes without saying that the present invention is not limited to this embodiment unless it exceeds the gist thereof.

Examples of the photosensitive layer peeling method of the electrophotographic photoreceptor according to the present invention will be described below.
Example 1
The surface of a cylindrical aluminum tube (JIS 3000 series) having a diameter of 100 mm was mirror-cut to produce a conductive support. Subsequently, a selenium-arsenic alloy was vacuum-deposited on the surface to form a photosensitive layer having a film thickness of 60 μm, and an electrophotographic photosensitive member was obtained.

The photosensitive layer was peeled off using the spray device and jig shown in FIG. As the dry ice particles, pellets shown in FIG. 1 (L = 2 to 4 mm, W = 2 to 3 mm) were used. The dry ice particle spray amount is 1.0 kg / min, the pressure applied to the photoconductor is 0.5 MPa, the spray distance between the spray nozzle and the photosensitive layer is 3 cm, the electrophotographic photoconductor speed is 4 rpm, dry ice The photosensitive layer was peeled off at a time set to 1.0 sec / cm ² for the particle photoreceptor to receive. After peeling off the photosensitive layer, a selenium-arsenic alloy was vacuum deposited again on the surface of the conductive support to form a photosensitive layer having a thickness of 60 μm, and the electrophotographic photosensitive member was regenerated.

Example 2
The photosensitive layer was peeled by the same method as in Example 1 except that dry ice particles having a mean particle size of 0.1 mm were used. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Example 3
The photosensitive layer was peeled off in the same manner as in Example 1 except that the pressure applied to the photoreceptor by dry ice particles was 1.0 MPa. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Example 4
The photosensitive layer was peeled in the same manner as in Example 1 except that the spray amount of dry ice particles was 2.0 kg / min. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Example 5
The photosensitive layer was peeled in the same manner as in Example 1 except that the time taken by the photoconductor for dry ice particles was 0.5 sec / cm ² . Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Example 6
The photosensitive layer was peeled off in the same manner as in Example 1 except that the time taken by the photoreceptor with dry ice particles was 5.0 sec / cm ² . Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Example 7
A charge generation layer made of a phthalocyanine pigment was formed on the surface of the conductive support in Example 1 by a dip coating method, and a charge transfer layer made of a butadiene compound was formed thereon by a dip coating method to form a photosensitive layer. The photosensitive layer was peeled off in the same manner as in Example 1 on the electrophotographic photoreceptor thus produced. In addition, a photosensitive layer composed of a charge generation layer made of a phthalocyanine pigment and a charge transfer layer made of a butadiene compound was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photoreceptor.

Comparative Example 1
The photosensitive layer was peeled in the same manner as in Example 1 except that the pressure applied to the electrophotographic photosensitive member by dry ice particles was 0.05 MPa. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Comparative Example 2
The photosensitive layer was peeled in the same manner as in Example 1 except that the pressure applied to the electrophotographic photosensitive member by dry ice particles was 1.5 MPa. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Comparative Example 3
The photosensitive layer was peeled off in the same manner as in Example 1 except that the spray amount of dry ice particles was 0.4 kg / min. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Comparative Example 4
The photosensitive layer was peeled off in the same manner as in Example 1 except that the spray amount of dry ice particles was 2.5 kg / min. Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Comparative Example 5
The photosensitive layer was peeled in the same manner as in Example 1 except that the time taken by the electrophotographic photosensitive member for dry ice particles was 0.1 sec / cm ² . Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

Comparative Example 6
The photosensitive layer was peeled in the same manner as in Example 1 except that the time taken by the electrophotographic photosensitive member for dry ice particles was 5.5 sec / cm ² . Further, a photosensitive layer similar to that of Example 1 was formed on the surface of the conductive support after peeling to regenerate the electrophotographic photosensitive member.

About the said Examples 1-7, evaluation about the following A, B, and C3 item was performed. The evaluation content A is an evaluation of whether or not there is any remaining residue of the photosensitive layer by observing the surface of the conductive support after peeling off the photosensitive layer with an optical microscope. The evaluation content B is obtained by measuring the surface of the conductive support after peeling off the photosensitive layer with a surface roughness meter, and evaluating scratches on the surface due to collision of dry ice particles. In this case, the presence / absence of scratches on the surface of the conductive support was evaluated using 10 μm asperities that have an effect on the image as a boundary. Furthermore, the evaluation content C was that the photosensitive layer was formed again after the photosensitive layer was peeled off to produce an electrophotographic photosensitive member, and the image evaluation with this electrophotographic photosensitive member was performed visually. Comparative Examples 1 to 6 were also evaluated for the items A, B, and C3.
The evaluation results are shown in Table 1.

A: presence or absence of residual residue on the surface of the conductive support after peeling of the photosensitive layer ○ ... no residual residue × ... remaining residue B: presence or absence of unevenness on the surface of the conductive support after peeling of the photosensitive layer (over 10 μm or more)
○: No irregularities ×: Irregularities C: Existence of black and white spots in the image where the photosensitive layer is formed again after peeling of the photosensitive layer ○… No black spots, white spots ×: With black spots or white spots

It is a perspective view which shows the shape of the dry ice particle applied to this invention. It is a structural example which shows one means for implementing the peeling method of the photosensitive layer based on this invention. It is a cross-sectional enlarged view of the AA line in the said FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pellet-shaped dry ice particle 10 Electrophotographic photosensitive member 11 Conductive support 12 Photosensitive layer 13, 14 Jig 15 Injecting device 17 Injecting nozzle 18 Dry ice particle

Claims (7)

An electrophotographic method comprising spraying dry ice particles sprayed with compressed air onto an electrophotographic photosensitive member having a photosensitive layer formed on the surface of a conductive support, and peeling the photosensitive layer from the surface of the conductive support. A method for removing a photosensitive layer of a photoreceptor. 2. The method for peeling off a photosensitive layer of an electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is made of an inorganic material or an organic material. 2. The method for peeling off a photosensitive layer of an electrophotographic photosensitive member according to claim 1, wherein the spray amount of the dry ice particles is in the range of 0.5 to 2 kg / min. 2. The method for peeling off a photosensitive layer from an electrophotographic photosensitive member according to claim 1, wherein the pressure applied to the electrophotographic photosensitive member by the dry ice particles is in the range of 0.1 to 1.0 MPa (mechanical skull). ^2. The method for peeling off a photosensitive layer of an electrophotographic photosensitive member according to claim 1, wherein the time taken by the electrophotographic photosensitive member for the dry ice particles is in the range of 0.5 to 5.0 sec / cm < ² >. The method for peeling off a photosensitive layer of an electrophotographic photosensitive member according to claim 1, wherein the dry ice particles are pellet-shaped or powder-shaped particles. 2. The method for peeling off a photosensitive layer from an electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is constituted by a drum, and sprayed while rotating the drum and moving dry ice particles along the rotation center axis of the drum.

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