JP4089122B2 - Contact charger manufacturing method, contact charger obtained by the method, charging method and image recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a contact charger, a contact charger obtained by the method, a charging method using the contact charger, and an image recording device such as a copying machine, a printer, and a facsimile equipped with the contact charger. It relates to the device.
[0002]
[Prior art]
Conventional charging systems have mainly been corotrons and scorotrons using corona discharge. However, since corona discharge applies an electric field in the air, ozone and NO_XThere are drawbacks such as the generation of a large amount of harmful substances such as, and the large amount of power consumption. Therefore, in recent years, environmental considerations are shifting to roller charging with less environmental impact.
[0003]
Roller charging is a method in which a charging roller (conductive rubber roller) is brought into contact with a photoconductor, and a discharge is generated in a minute gap between the photoconductor and the charging roller to charge the surface of the photoconductor. The amount of generated ozone is significantly reduced (reduced to 1/100 to 1/500).
[0004]
However, since the charging roller also applies a voltage to the minute gap between the photoconductor and the charging roller to cause corona discharge, the amount of ozone generated cannot be reduced to zero in principle. Further, the deterioration of the photoreceptor tends to be the same as or worse than that of corotron. Therefore, a charging method that does not generate ozone at all and does not deteriorate the photoreceptor is strongly desired. Recently, a charge injection method has been attracting attention.
[0005]
The charge injection method is a method in which charges are directly injected into the photosensitive layer from a contact charger without causing discharge. In principle, ozone is not generated and the photoreceptor is expected to be less deteriorated.
[0006]
In charge injection, the contact resistance between the contact-type charger and the photosensitive member affects the injection speed when the charge is injected, so it is considered that the lower the contact resistance, the better. Therefore, in the technique described in JP-A-6-75459, a charge transfer complex composed of an electron-accepting compound such as tetracyanoquinodimethane (TCNQ) and an electron-donating compound such as tetrathiafulvalene (TTF) is increased. The charging roller is made of a conductive rubber made of a polymer material substituted with a molecular network and imparted conductivity to the whole.
[0007]
However, Kagawa, Furukawa, Shinkawa et al., Japan Hardcopy '92, pp. In 287 to 290, an organic photoreceptor (hereinafter abbreviated as OPC) can obtain a sufficient charging voltage under a high humidity of 80% RH, but is charged up to half of the applied voltage under a humidity of 30 to 50% RH. However, it has been reported that the injection rate is slow. However, it can be considered that it is not easy to reduce the resistance of the conductive rubber while maintaining an appropriate rubber hardness from the viewpoint of selecting a polymer material.
[0008]
On the other hand, in the technique described in Japanese Patent Application Laid-Open No. 7-140729, charges are injected into the photoreceptor using a water-absorbing sponge roller. When a water-absorbing sponge roller is used, the water content of the roller has a great influence on the roller resistance and the charge injection speed, so that the charging potential may fluctuate due to the evaporation of moisture from the roller. In order to suppress the fluctuation of the charging potential, it is necessary to strictly control the evaporation of moisture from the roller over a long period of time, and the structure of the contact charger becomes complicated and cannot be manufactured at low cost.
[0009]
Japanese Patent Application Laid-Open No. 9-101649 discloses that the conductive fiber of the charging brush is an etching fiber or a split fiber, thereby increasing the contact area between the conductive fiber and the photoconductor and improving the charge injection speed. It has been proposed. By using conductive fibers as etching fibers or split fibers, conductive fibers having a substantially smaller diameter are used, and the contact area with the photoreceptor can be increased. However, the tensile strength of the divided fibers is lower by the amount of the divided fibers than the conductive fibers before the division. As a result, when it comes into contact with the photoreceptor, the divided fibers are likely to be cut, causing a variation in charging potential when used for a long period of time, which causes a decrease in the life of the contact charger. Conversely, when trying to obtain a long-life contact charger, the number of conductive fibers cannot be increased, so that a significant increase in contact area cannot be expected, and a significant improvement in charge injection rate cannot be achieved.
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems of the prior art. The first object of the present invention is to provide a sufficient and uniform charging voltage to a member to be charged with a low voltage._XIt is an object of the present invention to provide a method capable of producing a contact type charger at low cost, in which initial characteristics are maintained for a long period of time and mechanical damage is not easily caused to an object to be charged.
The second object of the present invention is to provide a contact charger obtained by the above manufacturing method, the third object is to provide a charging method using this contact charger, and the fourth object is to An object of the present invention is to provide an image recording apparatus provided with the contact charger.
[0011]
[Means for Solving the Problems]
  The method of manufacturing a contact charger according to claim 1 includes a frictional charging member, and the frictional charging member is slidably contacted with the surface of the object to be charged, while being in contact with the surface of the object to be charged and the frictional charging member. A method of manufacturing a contact charger for applying a potential difference to charge the object to be charged to a predetermined surface potential, mixing a base resin and a carbon nanotube, and forming the mixture into a predetermined shape, After stretching the molded product to obtain a conductive resin molded product, the conductive resin molded product is used as a support.By sticking and mechanically polishing and / or cutting the conductive resin molded product, a part of the carbon nanotube in the longitudinal direction is projected out of the conductive resin molded product.It is provided as the rubbing charging member.
[0012]
  The method of manufacturing a contact charger according to claim 2 is:A sliding charging member, and applying a potential difference between the charged body and the sliding charging member while the sliding charging member is in sliding contact with the surface of the charged body, A method of manufacturing a contact-type charger for charging to a surface potential, wherein a base resin and carbon nanotubes are mixed, the mixture is molded into a predetermined shape, and the molded product is stretched to form a conductive resin molded product. ,By mechanically polishing and / or cutting the conductive resin molded product, a part of the carbon nanotube in the longitudinal direction is projected outside the conductive resin molded product.Then, this is provided on the support as the rubbing charging member.It is characterized by that.
[0013]
  Of the present inventionMethod for manufacturing contact chargerInThe conductive resin moldingTheFilm or sheetIt can be.
[0014]
  Of the present inventionMethod for manufacturing contact chargerIn, The conductive resin molding is fibrousIt can be.
[0015]
  The contact charger is obtained by the method according to claim 1 or 2.Obtainable.
[0016]
  Claim3The described contact charger isA charger obtained by the method according to claim 1 or 2.It is a charging roller.
[0017]
  Claim4The described contact charger isA charger obtained by the method according to claim 1 or 2.It is a charging blade.
[0018]
  Claim5The described contact charger isA charger obtained by the method according to claim 1 or 2.It is a charging belt.
[0019]
  Claim6The described contact charger isA charger obtained by the method according to claim 1 or 2.It is a charging brush.
[0020]
  Claim7The charging method described in claim3~6Any one of the above-described contact-type chargers is used to charge a member to be charged to a predetermined surface potential.
[0021]
  Claim8The image recording apparatus according to claim3~6The contact charger according to any one of the above is provided.
[0022]
According to the method for manufacturing a contact charger of the present invention, a frictional charging member configured by arranging (orienting) carbon nanotubes by mixing a base resin and carbon nanotubes, and molding and stretching the mixture. The contact charger provided can be provided easily and at low cost.
[0023]
Further, the contact charger obtained by this method can be operated at a low voltage and can reduce the contact resistance, so that a sufficient charging voltage can be applied to the member to be charged in a short time. Moreover, carbon nanotubes have sufficient strength because they are chemically and mechanically stable and have high stability of conductive contacts, so that there are few fluctuations due to the environment.
[0024]
Furthermore, according to the contact charger of the present invention, ozone or NO_XCan be prevented, charging unevenness can be eliminated, and since the slidability (self-lubricating property) is high, problems such as damage to the charged body are reduced. The contact charger of the present invention also has the same effect with respect to static elimination.
[0025]
A carbon nanotube is a very fine substance having a fibrous structure in which one or several to several tens of cylinders having a rounded graphite-like carbon atom surface are arranged in a nested manner, and the diameter thereof is on the order of nanometers. . Carbon nanotubes have a wide range of electrical properties from metals to semiconductors depending on their structure. Moreover, it has a unique shape such as a small surface area, a large surface area, a large aspect ratio (length / diameter ratio), and a hollow shape. Furthermore, since it has special characteristics derived from its shape, various industrial applications are expected as a new carbon material. Carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes. A single-walled carbon nanotube with a rounded graphite-like carbon atom surface is called a single-walled carbon nanotube, and a plurality of carbon nanotubes are called a multi-walled carbon nanotube.
[0026]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. The scope of the present invention is not limited by this example.
<Example 1>
In the method of manufacturing a contact charger according to the present invention, after the base resin and the carbon nanotube are mixed, the mixture is molded into a predetermined shape, and then the molded product is stretched to obtain a conductive resin molded product. The conductive resin molding is provided on the support as the frictional charging member. First, the method for producing the conductive resin molded product and the arrangement (orientation) of carbon nanotubes by the stretching process of the molded product will be described with reference to FIG.
[0027]
First, carbon nanotubes were produced by a known technique. Helium was used as the atmospheric gas and 500 Torr (6.65 × 10 6^FourThe anode and cathode were synthesized by a DC arc discharge method using a graphite rod at a pressure of Pa). The amount of current was about 100 A, the electrode diameter was 1 cm, and the distance between the electrodes was about 1 mm. As a result, a cylindrical deposit having a diameter of about 1 cm was generated at the tip of the cathode, and a bundle of multi-walled carbon nanotubes was observed. Since the multi-walled carbon nanotubes after synthesis contain various impurities, they are dispersed in an organic solvent or an aqueous solution to which a surfactant is added, and then purified to high purity by centrifugation or ultrafiltration. .
[0028]
The purified multi-walled carbon nanotubes were mixed with powdered polyethylene (melting point 120 ° C.), heated to a temperature higher than the melting point of polyethylene (140 ° C.), melted and uniformly dispersed, and formed into a film. The film was stretched (uniaxial stretching) by pulling in one direction while heating the film to a temperature not lower than the glass transition temperature of polyethylene and not higher than the melting point (100 ° C.). By stretching, the longitudinal direction of the carbon nanotubes is aligned with the stretching direction. 1A shows the arrangement state of the carbon nanotubes 101 in the film (base resin 102, that is, polyethylene) before the stretching treatment, and FIG. 1B shows the arrangement state of the carbon nanotubes 101 in the film after the stretching treatment. It is a schematic diagram shown.
Note that “sliding direction A” and “sliding direction B” in FIG. 1B show specific examples of the rubbing contact direction of the rubbing charging member with respect to the body to be charged (not shown). According to the friction charging member using the processed film, there is an effect that an excellent charging result can be obtained in any of the sliding directions A and B.
[0029]
Film stretch ratio (%)
= [(Film length after stretching) / (film length before stretching)] × 100
2 is defined, and an angle between the stretching direction shown in FIG. 2 and the longitudinal direction of the carbon nanotube 101 is θ, and a parameter S (order parameter) indicating the degree of arrangement of the carbon nanotubes in the film is defined as θ.
S = (1/2) <3 cos²θ-1> (<> indicates a statistical average).
When the stretching process as shown in FIG. 1A is not performed, the arrangement is random, the order parameter S at that time is 0, and when all the carbon nanotubes match the stretching direction, S = 1. Become.
[0030]
As shown in FIG. 3, the order parameter S increases as the stretching ratio increases, and eventually saturates. Therefore, in order to produce a charger having a stable arrangement and thus stable characteristics, it is preferable to use a drawing ratio in a range where S is saturated.
[0031]
FIG. 4 is a schematic diagram showing the structure of the charging roller 401 and the charging method of the OPC 405 by this. In the production of the charging roller 401, the outer peripheral surface of a SUS metal core 404 having a diameter of 10 mm is covered with a conductive silicone rubber 403 having a thickness of 5 mm in which carbon black is dispersed, and the polyethylene film containing the carbon nanotubes is formed on the surface. A stretched product (stretched film) 402 was attached. In this case, the stretching direction C of the film was orthogonal to the rotation direction of the charging roller 401.
[0032]
Furthermore, the surface of the stretched film 402 was polished with alumina abrasive grains having a particle diameter of 3 μm, so that a part of the carbon nanotubes in the longitudinal direction protruded from the roller surface to form a charging roller 401. In Example 1, the stretched film 402 corresponds to the frictional charging member, and the metal core 404 corresponds to the support. Further, the resistance range of the stretched film 402 is 10 from the countermeasure against pinholes.²-10^TenIt is preferable to control to Ω · cm. Therefore, the carbon nanotube content of the stretched film 402 is 4 wt%.
[0033]
On the other hand, OPC405 was produced by a known technique. That is, on the Al substrate 407, a hole injection blocking layer made of titanium oxide fine particles was formed with a thickness of 5 μm by dip coating, and an organic photosensitive layer 406 in which a charge generation layer and a charge transport layer were laminated was formed thereon.
[0034]
The organic photosensitive layer 406 of the OPC 405 with a rotational peripheral speed of 250 mm / s was charged by bringing the charging roller 401 into contact with the nip width of 2 mm and rotating it. In this case, a potential difference of −500 V was applied between the stretched film 402 and the organic photosensitive layer 406 by the DC power source 408. As a result, a surface potential of −440 V was measured, and it was confirmed that the charging roller 401 had sufficient charging ability. In addition, it was confirmed that the charging without any unevenness was confirmed by the cascade development._XWas hardly detected. In addition, the carbon nanotubes are held by the resin film stretched as described above, so that the mechanical damage of the photoreceptor is remarkably reduced as compared to a film without carbon nanotubes, and the carbon nanotubes are simply held by the resin (unstretched) It was found that this was reduced compared with the case of holding with a resin film.
[0035]
In Example 1, multi-walled carbon nanotubes are used as carbon nanotubes, but single-walled carbon nanotubes can also be used. Moreover, the intended object of the present invention can be achieved regardless of whether the carbon nanotube is an open tube or a closed tube.
[0036]
Moreover, although the DC arc discharge method was used in the production of the carbon nanotube, as another method, (1) hydrocarbons such as benzene, ethylene, acetylene,₂(2) graphite, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, La, Y, which are pyrolytically decomposed at 1000-1500 ° C. while flowing a gas as a carrier gas A composite rod mixed with a metal catalyst such as a cathode is used as an anode, a graphite rod is used as a cathode, and 100 to 700 Torr (1.33 × 10 6^Four~ 9.31 × 10^FourPa) He or H₂A method for producing single-walled carbon nanotubes synthesized by arc discharge in an atmosphere, (3) the composite rod is heated to 1000 to 1400 ° C. in an electric furnace, and 500 Torr (6.65 × 10 6^FourA known method such as a method for producing a single-walled carbon nanotube that is irradiated with an Nd: YAG pulse laser in an Ar atmosphere of Pa) can be employed.
[0037]
Moreover, although polyethylene was used as the resin for stretching, polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyvinyl chloride (PVC), polyvinylidene chloride, polyvinyl alcohol (PVA), polyamide ( Various resins that are softened by heating or a solvent such as PA), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyurethane, and ethylene-vinyl alcohol copolymer can be employed.
[0038]
Further, in the charging roller 401, the resin conductive portion is provided on the metal core 404 in a double structure, but a single resin layer including carbon nanotubes or a multilayer structure of three or more layers may be used. Resistance control is not limited to carbon nanotubes alone, but is composed of an electron-accepting compound such as metal filler, carbon black, tetracyanoquinodimethane (TCNQ) and an electron-donating compound such as tetrathiafulvalene (TTF). A charge transfer complex can also be used in combination.
[0039]
Further, polishing is used as a method for causing the carbon nanotubes to protrude from the surface of the stretched resin, but a method using a chemical chemical solution, dry etching, ashing, or the like can also be used. Moreover, although negative charging using OPC has been shown, the present invention is not limited to this, and the same charger can be used for Se-based, a-Si, ZnO and other inorganic photoreceptors, other charged objects, and positive charging. Can be used. Further, although a DC voltage is applied as a voltage, there is no problem even if it is superimposed with an AC.
[0040]
In addition, the film stretching direction is perpendicular to the rotation direction of the charging roller 401. However, when the film is parallel, the function of the solid lubricant is more exhibited, the friction is small, and an angle of more than 0 ° and less than 90 ° is applied. Even in this case, a sufficient charging potential and a uniform charging result can be obtained. Further, although the OPC (charged body) is a driving roller and the charging roller is a driven roller, the charging roller may be a driving roller and the OPC may be a driven roller in order to provide a sufficient charging potential by extending the charging time. it can.
[0041]
<Example 2>
FIG. 5 is a schematic view showing a structure of a charging blade (blade-type contact charger) and a manufacturing method thereof. As shown in FIG. 5A, a stretched sheet 502 (polyethylene sheet: thickness 0.4 mm) in which carbon nanotubes 501 are arranged by stretching was formed by the same method as in Example 1. The compounding dispersion amount of the carbon nanotube 501 was 4 wt%. 5 layers of this sheet 502 are laminated as shown in FIG. 5A, bonded, and then cut perpendicularly to the arrangement direction (stretching direction) of the carbon nanotubes 501 to obtain carbon as shown in FIG. A part of the nanotube 501 in the longitudinal direction protruded from the cut surface 504 perpendicularly thereto. The laminated cut material is attached to the SUS substrate 506 using a conductive adhesive, and the cut surface 504 is polished in the same manner as in Example 1 so that the carbon nanotube array is partially lost by the cutting. The layer was removed. By this polishing, as shown in FIG. 5C, the internal carbon nanotubes 501 protrude vertically from the charging surface 507 of the charging blade 500.
[0042]
Charging was performed by bringing the charging blade 500 into contact with an OPC produced in the same manner as in Example 1. The nip width of the charging blade 500 was 2 mm. When a DC voltage of −500 V was applied and the rotational peripheral speed of the OPC was 200 mm / s, the surface potential was −460 V, and it was confirmed that the surface potential was sufficient. In addition, uniform charging was confirmed by cascade development. Furthermore, when continuously charged, ozone and NO_XWas hardly detected. In addition, the friction coefficient of the charging blade 500 is reduced to 1/2 to 1/10 that of the blade without carbon nanotubes, which is even smaller than when the carbon nanotubes are simply held by a resin. Damage was also reduced.
[0043]
In Example 2, a plurality of resin sheets in which carbon nanotubes are arranged by stretching are laminated, but there is no problem even if a single layer is used (one resin sheet is used). In addition, the case where the arrangement direction of the carbon nanotubes is perpendicular to the charging surface 507 is shown. However, the arrangement direction of the carbon nanotubes is in the charging surface, and the arrangement direction is perpendicular or parallel to the rotation direction of the OPC. In this case, even when the angle formed by the arrangement direction of the carbon nanotubes and the rotation direction of the OPC is more than 0 ° and less than 90 °, a sufficient charging potential is obtained, and it has been found that there is no charging unevenness.
[0044]
<Example 3>
FIG. 6 is a schematic diagram showing the conductive fiber 602 (brush hair) after the stretching treatment, which constitutes a charging brush body that is a main part of the charging brush (brush-type contact charger). A method for manufacturing the charging brush will be described. First, single-walled carbon nanotubes were produced by a known technique. Here, a composite rod in which Fe—Ni metal catalyst is mixed with graphite as an anode is used, and a graphite rod is used as a cathode, respectively, and 500 Torr (6.65 × 10 6) is used.^FourSingle-walled carbon nanotubes were produced by arc discharge in a He atmosphere of Pa). The single-walled carbon nanotube was purified using a centrifugal separation method and ultrafiltration. This single-walled carbon nanotube was dispersed in a nylon resin (dispersion amount 4 wt%), melt-spun, and then subjected to a stretching treatment to obtain a stretched conductive fiber.
[0045]
This stretched conductive fiber is sandwiched between urethane pads and 1 to 500 g / cm.²In the meantime, alumina having a particle diameter of 1 μm was supplied, the drawn fiber was pulled out from one side, the surface was mechanically polished, and the carbon nanotubes were projected from the fiber surface. The urethane pads arranged on the diagonal line were arranged so as to be orthogonal to two stages so that the carbon nanotubes protruded from the entire fiber surface. As a result, as shown in FIG. 6, the dispersed carbon nanotubes 601 were oriented in the drawing direction of the drawn conductive fibers 602. Depending on the load, the drawing speed, etc., one stage or a plurality of stages may be used.
[0046]
Here, melt spinning is used, but dry spinning, wet spinning, emulsion spinning, gel spinning, rapid heating spinning, and the like can also be employed. In addition, spinning and drawing were performed in two steps. (1) A straight-drawing method in which spinning and drawing were continuously performed, and (2) a semi-drawn yarn (POY: semi-drawn) by increasing the spinning speed. A method of drawing after obtaining Partially Oriented Yarn), and (3) a method of simultaneously spinning and drawing in one step by ultra-high speed spinning can also be used. Furthermore, these spinning, drawing and polishing steps may be integrated.
[0047]
The stretched conductive fibers 602 from which the carbon nanotubes were protruded in this way were planted in a holding member (support) 703 to produce a charging brush 701 shown in FIG. The flocking density is 50 to 300 / mm, similar to general charging brushes.²A good level. As shown in FIG. 7, charging was performed by contacting the OPC 704 produced in the same manner as in Example 1. In this figure, reference numeral 705 denotes an organic photosensitive layer, and reference numeral 706 denotes an Al substrate. The nip width of the charging brush 701 was 4 mm. When a DC voltage of −500 V was applied using the DC power supply 707 and the rotational peripheral speed of the OPC 704 was 250 mm / s, the surface potential was −450 V, and it was confirmed that the surface potential was sufficient. Further, it was confirmed that uniform charging can be obtained by cascade development. Furthermore, when continuously charged, ozone and NO_XWas hardly detected.
[0048]
Although an example of a fixed brush is shown here, a cylindrical rotating brush in which conductive fibers are implanted in a metal core by electric flocking may be used. In this case, the charging time can be extended even when the object to be forcibly rotated is driven. Further, in order to obtain a more sufficient charging potential, the rotating brush may be rotated in the direction opposite to the charged body. Further, as the fibers for the conductive fibers, rayon, acrylic fibers, and the like can be employed in addition to those made of the resins listed in Example 1.
[0049]
<Example 4>
FIG. 8 is a schematic diagram showing the structure of the charging belt 801 (belt-type contact charger) and the charging method using the structure. This endless charging belt 801 was produced by the following method. A stretched sheet 802 (polyethylene sheet: thickness 0.1 mm) in which carbon nanotubes are arranged was formed by stretching in the same manner as in Example 1. The amount of carbon nanotube dispersion was 4 wt%. This sheet was bonded to a silicone rubber belt 803 (thickness 3 mm) imparted with conductivity with carbon black so that the running direction of the charging belt 801 was orthogonal to the direction of stretching. The charging belt 801 has a two-layer structure composed of the stretched sheet 802 and a silicone rubber belt 803 that is a holding member (support) that holds the stretched sheet 802. However, the stretched sheet may be a single layer or a laminate of three or more layers. A belt may be used.
[0050]
The charging was performed by bringing the charging belt 801 into contact with the OPC 804 manufactured in the same manner as in Example 1. The nip width of the charging belt 801 (contact width with the OPC) was set to 4 mm, and the charging belt 801 was driven to follow the OPC 804. In FIG. 8, reference numeral 806 denotes an Al substrate, and reference numeral 805 denotes an organic photosensitive layer.
[0051]
When a voltage of −500 V was applied from the DC power supply 807, a surface potential of −430 V was measured when the peripheral speed of the OPC 804 was 250 mm / s, and it was confirmed that the battery had sufficient charging ability. In addition, uniform charging was confirmed by cascade development. Furthermore, when continuously charged, ozone and NO_XWas hardly detected. Further, in the charging belt 801, the carbon nanotubes are held by the stretched resin, so that the mechanical damage of the photoreceptor is remarkably reduced as compared with the charging belt not containing the carbon nanotubes. It was found that it was reduced compared to the case of holding.
[0052]
Although the charging belt 801 in FIG. 8 is driven by the member to be charged, the charging belt 801 may be run in the direction opposite to the rotation direction of the member to be charged in order to increase the charging time and further sufficiently charge. In addition, the drawing direction of the polyethylene sheet is shown as being perpendicular to the rotation direction of the member to be charged, but in the case of being parallel, the function of the solid lubricant is more accurately exhibited and the friction is reduced, and 0 ° is set. Even when the angle is greater than 90 °, sufficient charging potential is obtained, and it is confirmed that there is no charging unevenness.
[0053]
【The invention's effect】
  As is apparent from the above description, the present invention provides the following effects.
(1) Claim 1And 2Effects of the described contact charger manufacturing method: According to this manufacturing method, the base resin and the carbon nanotubes are mixed, and the mixture is formed and stretched to form and stretch the carbon nanotubes. A contact-type charger including a member can be provided easily and at low cost. Further, in this manufacturing method, since the alignment process of the carbon nanotubes is performed by stretching the base resin, the alignment process is easier than a method using rubbing or the like, and a large amount of friction charging members are manufactured. Can do.
[0054]
  In particular,As a method for projecting a part of the longitudinal direction of the bonn nanotube from the surface of the conductive resin molding, at least one of mechanical polishing and cutting of the conductive resin molding is used. It can be manufactured at low cost and in large quantities.
[0055]
(2) Claim1 or 2Effect by the described contact-type charger: The frictional charging member of the contact-type charger obtained by the above production method contains carbon nanotubes arranged in the stretched base resin. Therefore, in this contact type charger, carbon nanotubes are present on the surface in contact with the object to be charged (or the object to be neutralized), so that it is much better than conventional corotron and scorotron chargers, and in the conventional contact type charger. Compared with this, it is possible to apply a sufficient charging voltage to the object to be charged at a lower voltage (to sufficiently neutralize the object to be discharged), as well as ozone and NO._XThe generation amount of can be greatly reduced.
[0056]
In the contact charger, even if the surface layer of the frictional charging member is worn, carbon nanotubes inside the base resin (inside the conductive resin molding) protrude from the surface. Can be maintained, and stable charging (static elimination) becomes possible. Furthermore, since the carbon nanotube has a small friction coefficient, it is difficult to cause mechanical damage to the charged body (or the discharged body), such as ozone and NO._XIt is possible to extend the life of the photosensitive member in combination with the fact that no occurrence occurs. Further, in the contact charger, since the carbon nanotubes are arranged, there is no charging unevenness.
[0057]
(3) Claim3Advantages of the described contact-type charger: This contact-type charger is a charging roller that comes into contact with a member to be charged (or a member to be discharged) mainly by carbon nanotubes. Carbon nanotubes are chemically stable because they do not have dangling bonds, and have a very high mechanical strength due to their seamless structure. Therefore, the stability of the conductive contact is very good, compared to the conventional conductive rubber and water-absorbing sponge roller, which has been imparted with conductivity overall, there is less fluctuation due to the environment and stable over the long term Charge (static charge) capability can be maintained. In addition, a sufficient charging potential can be applied (charge removal) by bringing the object to be charged (or the charge removal object) into contact mainly with the carbon nanotube.
[0058]
In addition, even if wear occurs on the surface layer of the frictional charging member, the carbon nanotubes inside the base resin protrude from the surface, so the initial characteristics can be maintained and stable charging (static elimination) is possible. It becomes. In addition, unlike conventional charging rollers, ozone and NO_XTherefore, the deterioration of the photoreceptor due to these is reduced and the life can be extended. Furthermore, since the carbon nanotubes are held by the stretched resin, mechanical damage is reduced and there is no uneven charging. Furthermore, since the alignment process of the carbon nanotubes is performed by stretching the base resin, the alignment process is easier than a method using rubbing or the like, and a large amount of frictional charging members can be produced. be able to.
[0059]
(4) Claim4Effect by the described contact-type charger: This contact-type charger is a charging blade that comes into contact with an object to be charged (or an object to be discharged) mainly by carbon nanotubes. Carbon nanotubes function as a solid lubricant and can reduce the friction coefficient between the charging blade and the photosensitive layer compared to conventional charging blades without carbon nanotubes, resulting in mechanical damage to the charged object (or discharged object). The lifetime of the photosensitive layer, particularly the organic photosensitive layer, can be improved. In addition, a sufficient charging potential can be applied (discharged) by bringing the object to be charged (or the object to be discharged) into contact with mainly the carbon nanotube. In addition, even if wear occurs on the surface layer of the frictional charging member, the carbon nanotubes inside the base resin protrude from the surface, so that the initial characteristics can be maintained and stable charging (static elimination) is possible. It becomes. Furthermore, by holding the carbon nanotubes with the stretched resin, mechanical damage can be reduced and there is no uneven charging. Furthermore, since the carbon nanotubes are arranged by stretching the resin, it is easier than a method using rubbing or the like and can be produced in large quantities, so that it can be produced at low cost.
[0060]
(5) Claim5Effect by the described contact-type charger: This contact-type charger is a charging belt that is in contact with an object to be charged (or an object to be discharged) mainly by carbon nanotubes. Carbon nanotubes function as a solid lubricant and can reduce the coefficient of friction between the charged belt and the object to be charged compared to conventional charging belts without carbon nanotubes. It is possible to improve the life of the photosensitive layer, particularly the organic photosensitive layer. Further, by contacting the object to be charged (or the object to be neutralized) mainly with carbon nanotubes, it is possible to give a sufficient charging potential (to eliminate the charge) as compared with a conventional charging belt. In addition, even when wear or the like occurs in the film or sheet that is a carbon nanotube holder, the initial characteristics can be maintained because the internal carbon nanotubes protrude from the surface, and stable charging becomes possible. Furthermore, since the carbon nanotubes are held by the stretched resin, mechanical damage can be reduced and there is no uneven charging. Since the carbon nanotubes are oriented by stretching the resin, it is easier than a method using rubbing or the like, and can be produced in large quantities, so that it can be produced at low cost.
[0061]
(6) Claim6Advantages of the described contact charger: This contact charger is a charging brush having a structure in which carbon nanotubes are held by conductive fibers. By making contact with the object to be charged (or neutralizing body) mainly with carbon nanotubes, it is possible to give a sufficient charging potential (to eliminate static electricity) compared to conventional charging brushes in which conductive fibers are made of etched fibers and split fibers. And strength is sufficient. In addition, even if abrasion or the like occurs on the surface of the conductive fiber, the internal carbon nanotubes protrude from the surface, so that the initial characteristics can be maintained and stable charging (static elimination) is possible. Furthermore, since the carbon nanotubes are held by the stretched resin, there is no uneven charging. Since the carbon nanotubes are arranged by stretching the resin, it is easier than a method using rubbing or the like and can be produced in large quantities, so that it can be produced at low cost.
[0062]
(7) Effects of the charging method according to claim 7:3~6Since the contact-type charger described in any of the above is used, the above-described effects of these contact-type chargers can be obtained.
[0063]
(8) Claim8The effect of the image recording apparatus according to claim 1 is:3~6Since the contact-type charger described in any of the above is used, the above-described effects of these contact-type chargers can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the alignment (orientation) of carbon nanotubes by stretching a base resin, wherein (a) shows an unstretched base resin, and (b) shows a base resin after stretching. Show.
FIG. 2 is an explanatory diagram of an angle θ formed by a stretching direction of a base resin and a longitudinal direction of a carbon nanotube.
FIG. 3 is a graph qualitatively showing the relationship between the stretching ratio of the base resin and the degree of arrangement of the carbon nanotubes.
FIG. 4 is an explanatory diagram showing a structure of a charging roller according to Embodiment 1 of the present invention and a charging method using the same.
FIG. 5 is an explanatory diagram showing a structure of a charging blade according to a second embodiment of the present invention and a manufacturing method thereof.
FIG. 6 is a perspective view showing conductive fibers (charging brush body: charging brush bristles) according to Example 3 of the invention.
7 is an explanatory view showing a structure of a charging brush constructed using the conductive fiber of FIG. 6 and a charging method using the charging brush.
FIG. 8 is an explanatory diagram showing a structure of a charging belt according to a fourth embodiment of the present invention and a charging method using the same.
[Explanation of symbols]
101 carbon nanotube
102 Base resin
401 Charging roller
402 Stretched film
403 conductive silicone rubber
404 metal core
405 OPC
406 Organic photosensitive layer
407 Al base
408 DC power supply
500 Charging blade
501 Carbon nanotube
502 Stretched sheet
504 Cut section
506 SUS substrate
507 Charged surface
601 Carbon nanotube
602 Conductive fiber (drawn fiber)
701 Charging brush
703 Holding member (support)
704 OPC
705 Organic photosensitive layer
706 Al base
707 DC power supply
801 Charging belt
802 Stretched sheet
803 Holding member (support)
804 OPC
805 Organic photosensitive layer
806 Al base
807 DC power supply

Claims (8)

A sliding charging member, and applying a potential difference between the charged body and the sliding charging member while the sliding charging member is in sliding contact with the surface of the charged body, A method of manufacturing a contact-type charger for charging to a surface potential, which comprises mixing a base resin and carbon nanotubes, forming the mixture into a predetermined shape, and subjecting the molded product to a stretching treatment to produce a conductive resin molded product. Then, the conductive resin molded product is attached to a support , and the conductive resin molded product is mechanically polished and / or cut to remove a part of the carbon nanotube in the longitudinal direction from the conductive resin molded product. The contact charger is provided as the rubbing charging member by projecting to the contact charging device. A sliding charging member, and applying a potential difference between the charged body and the sliding charging member while the sliding charging member is in sliding contact with the surface of the charged body, A method of manufacturing a contact-type charger for charging to a surface potential, wherein a base resin and carbon nanotubes are mixed, the mixture is molded into a predetermined shape, and the molded product is stretched to form a conductive resin molded product. Then, by mechanically polishing and / or cutting the conductive resin molded product, a part of the carbon nanotube in the longitudinal direction is projected outside the conductive resin molded product, and this is then rubbed on the support. A method of manufacturing a contact-type charger, characterized by being provided as a charging member. A contact-type charger, wherein the charger obtained by the method according to claim 1 is a charging roller. A contact-type charger, wherein the charger obtained by the method according to claim 1 or 2 is a charging blade. A contact-type charger, wherein the charger obtained by the method according to claim 1 is a charging belt. A contact-type charger, wherein the charger obtained by the method according to claim 1 is a charging brush. A charging method comprising charging a member to be charged to a predetermined surface potential using the contact charger according to any one of claims 3 to 6 . An image recording apparatus comprising the contact charger according to any one of claims 3 to 6 .

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