JP5338103B2 - Elastic member for image forming apparatus, charging device for image forming apparatus, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic member in which the deposition of low molecule components such as impurities, a plasticizer or an ion conductor to a surface layer surface in an elastic layer is suppressed, and to provide an image forming apparatus in which a void in an image is suppressed. <P>SOLUTION: The image forming apparatus is provided with at least: the elastic member provided with an elastic layer 124, a cover layer 126A containing carbon atoms and formed of a covering material with both an SP2 structure and SP3 structure by the carbon atom and a surface layer 132 in this order on a base material 122; an image holding body; a charging means for charging the image holding body; a latent image forming means for forming an electrostatic latent image on a surface of the image holding body; a developing means for visualizing a latent image formed on the image holding surface as a toner image by being developed by a toner; and a transfer means for transferring the toner image on the recording medium. The charging means provided with the elastic member is used as the charging means. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an elastic member for an image forming apparatus, a charging device for the image forming apparatus, and an image forming apparatus.

  In a charging device that uses an elastic roll as a charging member in contact with an image carrier such as a photoconductor, low molecular components such as impurities, plasticizers, and ionic conductive agents in the elastic layer move in the elastic layer. There was a problem that so-called bleed or bloom occurred on the surface. The deposited low molecular weight component is transferred to the surface of the image carrier, and it is recognized as a problem that white spots occur on the image. For this reason, a method has been proposed in which the type of ionic conductive agent to be used is limited or a bleed phenomenon is avoided by using electronic conductive carbon black or the like as the conductive agent (for example, see Patent Document 1).

  Also, there is a method of physically preventing bleed by applying a polymer material having a function of preventing bleed to the lower part (base material side) of the surface layer. For example, a method of physically blocking with a coating material such as diamond coating is conceivable (see, for example, Patent Document 2).

On the other hand, in a charging device that uses an elastic roll as a charging member in contact with an image carrier such as a photosensitive member, HCl is generated when the elastic layer absorbs moisture and erodes the base material. The part was formed on the surface layer, and there was a problem of image defects. On the other hand, conventionally, a method for preventing rust by applying plating to a base material has been proposed (see, for example, Patent Documents 3 and 4).
JP 2007-133144 A JP 2002-338388 A JP-A-11-294446 JP 2000-213530 A

An object of the present invention is to provide an elastic member for an image forming apparatus in which precipitation of low molecular components such as impurities and plasticizers and ionic conductive agents in the elastic layer on the surface of the surface layer, impurities and plasticizers in the elastic layer, An object of the present invention is to provide a charging device for an image forming apparatus in which precipitation of a low molecular component such as an ionic conductive agent on the surface of the surface layer is suppressed, and an image forming apparatus in which whiteout of an image is suppressed.
Another object of the present invention is to suppress the rust of the base material and suppress the occurrence of convex portions on the surface of the surface layer, an elastic member for an image forming apparatus, suppress the rust of the base material, and the convex portions on the surface of the surface layer. It is an object of the present invention to provide a charging device for an image forming apparatus in which the occurrence of image defects is suppressed and an image forming apparatus in which the occurrence of image defects due to convex portions is suppressed.

The above object is achieved by the present invention described below.
That is, the invention according to claim 1 includes an elastic layer, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, a resin and a conductive material. An elastic member for an image forming apparatus having a surface layer containing an agent in this order.

  In the invention according to claim 2, the surface roughness of the surface in contact with the coating layer in the layer formed in contact with the substrate side surface of the coating layer is (Sm1), and the film thickness of the coating layer is (T1). 2. The elastic member for an image forming apparatus according to claim 1, wherein a relationship of Sm1 ≧ T1 is satisfied.

  The invention according to claim 3 is the elastic member for an image forming apparatus according to claim 1, wherein the elastic layer has a region exposed on a surface.

  The invention according to claim 4 has a coating layer formed of a coating material which is formed so as to be in contact with at least the surface of the base material and which includes carbon atoms and which has both the SP2 structure and the SP3 structure based on the carbon atoms. An elastic member for an image forming apparatus having an elastic layer and a surface layer in this order on a layer.

  The invention according to claim 5 has a relationship of Sm2 ≧ T2 when the surface roughness of the surface of the substrate in contact with the coating layer is (Sm2) and the film thickness of the coating layer is (T2). The elastic member for an image forming apparatus according to claim 4.

  The invention according to claim 6 has a first coating layer that is formed so as to be in contact with at least the surface of the substrate, and is formed of a coating material that includes carbon atoms and has both the SP2 structure and the SP3 structure of the carbon atoms. And an elastic layer on the first coating layer, a second coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, and a surface layer in this order. The elastic member for an image forming apparatus according to claim 1, wherein the elastic member is an image forming apparatus.

The invention according to claim 7 includes an elastic layer on at least a substrate, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, a resin and a conductive agent. A charging device for an image forming apparatus , comprising: a charging member having a surface layer including: a surface layer in this order;

  The invention according to claim 8 is the charging device for an image forming apparatus according to claim 7, wherein the charging member has a roll shape.

  The invention according to claim 9 is the charging device for an image forming apparatus according to claim 7 or 8, further comprising cleaning means for cleaning the surface of the charging member in contact with the surface.

  The invention according to claim 10 has a coating layer formed of a coating material which is formed so as to be in contact with at least the surface of the base material and includes carbon atoms and which has both the SP2 structure and the SP3 structure based on the carbon atoms. A charging device for an image forming apparatus, comprising a charging member having an elastic layer and a surface layer in this order on a layer, and charging a charged object by the charging member.

  According to an eleventh aspect of the present invention, in the charging device for an image forming apparatus according to the tenth aspect, the charging member has a roll shape.

The invention according to claim 12 is formed on the surface of the image carrier, a charging unit for charging the image carrier, a latent image forming unit for forming an electrostatic latent image on the surface of the image carrier. At least a developing unit that develops the latent image with toner and visualizes the toner image as a toner image, and a transfer unit that transfers the toner image to a recording medium. A charging device comprising a charging member having a layer, a coating layer containing carbon atoms and a coating layer formed of a coating material having both an SP2 structure and an SP3 structure based on the carbon atoms , and a surface layer containing a resin and a conductive agent in this order An image forming apparatus using the means.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, the image carrier has a surface protective layer having a high hardness.

  According to a fourteenth aspect of the present invention, an image carrier is formed on the surface of the image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier. And developing means for developing the latent image with toner into a visible image as a toner image, and transfer means for transferring the toner image to a recording medium. The charging means is at least in contact with the substrate surface. And a coating layer formed of a coating material containing carbon atoms and having both an SP2 structure and an SP3 structure based on the carbon atoms, and having an elastic layer and a surface layer in this order on the coating layer An image forming apparatus using a charging unit including a member.

  According to the first aspect of the invention, compared to the case where the coating layer of this configuration is not provided, precipitation of low molecular components such as impurities in the elastic layer, plasticizer, and ionic conductive agent on the surface of the surface layer is suppressed. .

  According to the second aspect of the invention, compared to the case where there is no relationship of Sm1 ≧ T1, the precipitation of low molecular components such as impurities, plasticizers and ionic conductive agents in the elastic layer on the surface of the surface layer is further suppressed. The resulting coating layer can be obtained.

  According to the third aspect of the present invention, the swelling of the elastic layer is suppressed even when a low molecular component is generated more than when the elastic layer does not have a region exposed on the surface.

  According to the invention which concerns on Claim 4, compared with the case where it does not have the coating layer of this structure, the rust of a base material is suppressed and generation | occurrence | production of the convex part in the surface layer surface is suppressed.

  According to the invention which concerns on Claim 5, compared with the case where it does not have the relationship of Sm2> = T2, the rust of a base material is suppressed and it can be set as the coating layer which can suppress generation | occurrence | production of the convex part in the surface layer surface more. .

  According to the invention which concerns on Claim 6, compared with the case where it does not have the 1st coating layer and 2nd coating layer of this structure, it is low molecular-components, such as an impurity in an elastic layer, a plasticizer, and an ionic conductive agent. While the precipitation to the surface layer surface is suppressed, the rust of a base material is suppressed and generation | occurrence | production of the convex part in a surface layer surface is suppressed.

  According to the seventh aspect of the invention, the surface layer of the low molecular component such as impurities, plasticizer, ionic conductive agent and the like in the elastic layer has excellent chargeability as compared with the case where the coating layer of this configuration is not provided. Precipitation on the surface is suppressed.

  According to the eighth aspect of the present invention, the occurrence of image quality defects such as black streaks is reduced compared to a case where the shape is not a roll shape, and it is easy to provide a cleaning device on the charging surface, which is highly reliable and has a long life. A long charging device is realized.

  According to the invention which concerns on Claim 9, peeling of a coating layer is suppressed compared with the case where it does not have a coating layer of this structure in the base material side from a surface layer.

  According to the tenth aspect of the present invention, as compared with the case where the coating layer of this configuration is not provided, it has excellent chargeability, rust of the base material is suppressed, and occurrence of convex portions on the surface of the surface layer is suppressed. .

  According to the eleventh aspect of the present invention, the occurrence of image quality defects such as black streaks is reduced compared to the case where the shape is not a roll shape, and it is easy to provide a cleaning device on the charging surface, which is highly reliable and has a long life. A long charging device is realized.

  According to the twelfth aspect of the invention, compared to the case where the coating layer having this configuration is not provided, white spots of the image are suppressed and an image having excellent image quality is formed.

  According to the thirteenth aspect of the present invention, the occurrence of filming on the surface of the image carrier due to the low molecular component precipitated from the elastic layer is suppressed as compared with the case where the coating layer having this configuration is not provided.

  According to the fourteenth aspect of the present invention, the occurrence of image defects due to the convex portions is suppressed, and an image with excellent image quality is formed, as compared with the case where the coating layer having this configuration is not provided.

[First image forming apparatus]
Hereinafter, an image forming apparatus according to the first embodiment which is a preferable aspect (hereinafter referred to as “first image forming apparatus”) will be described in detail.
The first image forming apparatus is formed on an image holding member, a charging unit that charges the image holding member, a latent image forming unit that forms an electrostatic latent image on the surface of the image holding member, and an image holding member surface. At least a developing unit that develops the latent image with toner and visualizes the toner image as a toner image, and a transfer unit that transfers the toner image to a recording medium. The charging means includes a charging member including a layer, a coating layer containing carbon atoms and a coating material having both the SP2 structure and the SP3 structure of the carbon atoms, and a surface layer in this order.
However, a surface layer containing a resin and a conductive agent is applied to the surface layer of the charging member of the first image forming apparatus.

  The first image forming apparatus is illustrated in FIG. A first image forming apparatus shown in FIG. 1 includes a photoconductor 10 as an image carrier, and a charging roll 12 as a charging device (charging member) around which the surface of the photoconductor 10 is charged, and an exposure device. 14, a developing device 16, and a cleaning device 18, and a transfer roll 20 is further provided. Further, a cleaning device 24 is provided around the charging roll 12 as a cleaning unit that cleans the surface of the charging roll 12.

  The photosensitive member 10 is rotationally driven at a predetermined surface speed (for example, about 100 mm / sec) along the arrow direction. A charging roll 12 is in contact with the surface of the photoreceptor 10. The charging roll 12 is disposed so as to be driven and rotated by the rotation of the photoreceptor 10. Then, the surface of the photoreceptor 10 is charged to a predetermined potential of about −700V. Thereafter, an image exposure is performed by the exposure device 14 on the surface of the photoconductor 10 so that the exposed portion is neutralized, and an electrostatic latent image corresponding to the image information is formed. The electrostatic latent image formed on the surface of the photoconductor 10 is developed in a state where the potential of the image portion is at a level of −150 V or less and a developing bias of about −600 V is applied by the developing device 16. A negative toner image is formed on the surface. The developed toner image reaches an area (transfer portion) sandwiched between the rotating transfer roll 20 and the photosensitive member 10 by the rotation of the photosensitive member 10, and is transferred onto the transfer material 22. At this time, a voltage of about 1000 V or more and 4000 V or less is applied to the transfer roll 20. The transfer material 22 onto which the toner image has been transferred is conveyed to a fixing device (not shown), and the toner image is fixed on the transfer material 22 by heat and / or pressure.

Toner that has not been transferred onto the transfer material 22 remains on the photosensitive member 10 after transfer as deposits. The residual toner is removed from the surface of the photoconductor 10 by the cleaning device 18 that contacts the surface of the photoconductor 10. Further, when residual toner or the like that has not been removed from the surface of the photoreceptor 10 still adheres to the surface of the charging roll 12, the surface of the charging roll 12 is cleaned by the cleaning device 24 that contacts the surface of the charging roll 12. . Thereafter, the surface of the clean photoreceptor 10 reaches the charging device 12 as it rotates, and the above-described series of operations is repeated.
The image forming apparatus can be a cleanerless image forming apparatus that does not require the cleaning device 18.

  Hereinafter, each member provided in the first image forming apparatus will be described in detail.

(Charging device)
The charging device includes a charging member that performs charging by contacting a photoreceptor (charged body). The charging member in the first embodiment has an elastic layer, a coating layer, and a surface layer as described above, and the shape thereof is formed in a roll shape. In addition, the shape is not limited as long as it has the above-described layer structure, can stably contact with the object to be charged, and can apply a charge to the surface of the object to be charged by applying a voltage. It can be in various shapes such as a plate shape, a block shape, and a spherical shape. Among these, it is more preferable that the film is formed in a roll shape. Because of the roll shape, the surface that is always in contact with the photoconductor 10 is changed, so that, for example, a minute external additive that has passed through the cleaning device 18 accumulates on the charged surface and causes image quality defects such as black stripes. Occurrence is reduced. In addition, the roll shape makes it easy to provide the cleaning device 24 on the charging surface, and the charging device 12 with higher reliability and longer life can be realized.

  The layer structure of the charging roll 12 as a charging member is shown in FIG. An elastic layer 124 is formed on a solid columnar or hollow cylindrical base material 122, and the coating material further includes carbon atoms on the elastic layer 124 and has both the SP2 structure and the SP3 structure based on the carbon atoms. The covering layer 126A formed in the above is formed. A surface layer 132 as the outermost layer is formed on the covering layer 126 </ b> A via the resistance adjusting layer 128 and the protective layer 130.

-Base material-
The base material 122 functions as an electrode and a supporting member of the charging member, and includes, for example, a metal or alloy such as aluminum, copper alloy, and stainless steel; iron plated with chromium, nickel, etc .; conductive resin; (Here, conductive means a volume resistivity in the range of 1.0 × 10 ⁹ Ωcm or less, and the same applies hereinafter).

-Elastic layer-
The elastic layer 124 forms a contact region with the member to be charged so that the charging member contacts the surface of the member to be charged with an appropriate pressure, and the surface of the member to be charged can be satisfactorily charged. To be provided.
Note that the charging roll 12 in the first embodiment preferably has a region where the elastic layer 124 is exposed on the surface. As an aspect exposed on the surface, for example, an aspect in which the elastic layer 124 is exposed on both axial surfaces of the charging roll 12 (more specifically, the side surfaces (both axial ends) of the charging roll 12 are covered). And the layer structure of the charging roll 12 is formed so that it can be observed as it is, and the elastic layer 124 is also exposed).

  The elastic layer 124 is formed, for example, by dispersing a conductive agent in a rubber material. Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, urethane rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, ethylene-propylene. -Diene copolymer rubber, acrylonitrile-butadiene copolymer rubber, natural rubber and the like, and blended rubbers thereof. Of these, isoprene rubber, silicone rubber, and ethylene propylene rubber are preferably used. These rubber materials may be foamed or non-foamed.

  In addition to the above, a foam in which a conductive agent is dispersed is also used as the elastic layer 124. Examples of the foam include sponge (open cell), foamed plastic (closed cell), rubber foam, non-woven fabric, and polystyrene foam. Among them, a foam made of a polymer material having open cells and closed cells is preferably used.

Note that the foam as the elastic layer 124 has irregularities on the surface thereof, and comes into contact with the surface of the elastic layer 124 on the surface layer 132 side from the viewpoint of forming a coating layer 126A, which will be described later, and from the viewpoint of good chargeability. Thus, it is preferable to form an intermediate layer made of a rubber material or a resin.
As the material of the intermediate layer, rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, urethane rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide. Examples thereof include copolymer rubber, ethylene-propylene-diene copolymer rubber, acrylonitrile-butadiene copolymer rubber, natural rubber, and blended rubbers thereof. Examples of the resin include polyester, polyamide, polyethylene, polycarbonate, polyolefin, polyurethane, polyvinylidene fluoride, polyimide, PEN, PEK, PES, PPS, PFA, PVdF, ETFE, and CTFE.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide Examples thereof include fine powders such as various conductive metal oxides such as tin oxide-antimony oxide solid solution and tin oxide-indium oxide solid solution; Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals Can be mentioned.

  These conductive agents may be used alone or in combination of two or more. The amount of addition is not particularly limited, but in the case of the electronic conductive agent, the amount is preferably in the range of 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the rubber material or foam. More preferably, it is in the range of not less than 35 parts and not more than 35 parts by mass. On the other hand, in the case of the ionic conductive agent, the range is preferably 0.01 parts by mass or more and 5 parts by mass or less, and 0.1 parts by mass or more and 4 parts by mass or less with respect to 100 parts by mass of the rubber material or foam. More preferably, it is the range.

Thereby, it is preferable to adjust the volume resistance value of the elastic layer 124 to a range of 2 × 10 ² Ωcm to 5 × 10 ⁹ Ωcm. This volume resistance value is closely related to the volume resistance value of the resistance adjustment layer 128 described later. The elastic layer 124 preferably has an Asker C hardness of 70 ° or less.

-Coating layer-
In the charging roll 12 according to the first embodiment, the covering layer 126A is formed on the elastic layer 124 (when the elastic layer 124 is a foam, preferably on the intermediate layer as described above).
First, “a material containing both carbon atoms and having both an SP2 structure and an SP3 structure (hereinafter simply referred to as“ amorphous carbon ”)” constituting the covering layer 126A will be described with reference to the drawings. FIG. 3 is a conceptual diagram showing the relationship due to the difference in bonding of the amorphous carbon in an easy-to-understand manner.
Carbon has different numbers of atoms that can be bonded due to the difference in hybrid orbitals. As shown in FIG. 3, the crystal structure is composed of graphite composed of SP2-bonded carbon atoms and high hardness composed of SP3-bonded carbon atoms. Can be classified as diamond. The amorphous carbon is an amorphous film composed of carbon atoms in which SP2 bonds and SP3 bonds are mixed (that is, a region surrounded by a triangle in FIG. 3).

Among these, the amorphous carbon in the first embodiment is a tetrahedra having a hydrogen atom content of 10 atm% or less and a SP3 bonded carbon atom ratio of 40% or more for the reasons described later. Particularly preferred is amorphous carbon ("Ta-C" shown in FIG. 3).
Here, “Ga-C” in FIG. 3 represents graphite-based (close to graphite) amorphous carbon (that is, amorphous carbon having an SP3 bond of less than 40%), and “aCH” represents amorphous Hydrogenated Carbon.

  The coating layer 126A formed of the amorphous carbon can control the hardness by controlling the bonding state of carbon atoms. In order to control the bonding state of carbon atoms, it is necessary to control the energy state of sputtered carbon atoms when they reach the surface on which amorphous carbon is formed. The method of controlling the state is considered effective.

  The coating layer 126A formed of amorphous carbon is formed by, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), filter / cathode / vacuum arc (FCVA), or the like. be able to. Among these, the FCVA method is particularly preferable from the viewpoint that the variation in the energy state of carbon atoms can be satisfactorily suppressed and the SP3 bond ratio can be increased as described later. The FCVA method can irradiate filtered ions without variation, and can form a thin layer with a high SP3 bond ratio. Further, according to the FCVA method, a film can be formed faithfully to the shape of the formation surface.

Here, the formation of the Ta—C layer will be described in more detail.
In forming the Ta-C layer, carbon atoms, carbon atoms and other desired atoms, or other plural atoms are converted into plasma, and the ionized atoms are formed on the elastic layer 124 (the elastic layer 124 is a foam). In some cases, it is preferably deposited on the intermediate layer as described above. As the Ta—C layer, it is preferable that the ratio of the SP3 structure to the sum of the SP2 structure and the SP3 structure is 40% or more and 85% or less from the viewpoint of conductivity and wear resistance.
For example, the Ta-C layer can be formed by the FCVA technique described above. The FCVA technique itself is conventionally known, for example, a charging device, but a wear resistant film is formed on a magnetic disk. And a method described in Japanese Patent Application Laid-Open No. 2005-173141 for forming a wear-resistant film on the surface of the developing roll can be employed.

Here, the FCVA apparatus will be described with reference to the drawings.
FIG. 4 is a conceptual diagram illustrating the FCVA device. Reference numeral 40 denotes a carbon ion generation source, which generates carbon ions C ⁺ by vacuum arc discharge in a region sandwiched between the cathode 41 and the anode 42. The cathode 41 is made of disk-shaped high purity graphite. Carbon ions C ⁺ generated from the carbon ion generation source 40 pass through the filter 43 and are then formed on the sample T. The filter 43 allows only necessary carbon ions to pass through using an electric field and a magnetic field. Unnecessarily large carbon particles and neutral carbon atoms are removed by the filter 43.

  A magnetic coil 44 is provided at the outlet of the filter 43, and the magnetic coil 44 is controlled so that an amorphous carbon film formed on the sample T is favorably formed by scanning a carbon ion beam. A bias voltage can be applied to the sample T. The energy of ions reaching the sample T depends on the bias voltage, and the film characteristics can be changed by the bias voltage.

  When manufacturing the charging roll 12 in the first embodiment, the covering layer 126A can be formed by disposing the base material 122 on which the elastic layer 124 is formed at the position of the sample T. Specifically, it can be carried out by a filter-cathode-vacuum-arc (FCVA) method in which carbon plasma is generated by graphite vacuum arc discharge, and ionized carbon is extracted and deposited therefrom. Can be used. As formation conditions, a film formation temperature of 0 ° C. or higher and 80 ° C. or lower (more preferably 20 ° C. or higher and 80 ° C. or lower, particularly preferably 40 ° C. or higher and 80 ° C. or lower) and a film formation rate of 1.5 nm / s are preferable.

[Physical properties of coating layer (amorphous carbon layer)]
(1) Content of Hydrogen Atoms The charging roll 12 in the first embodiment has a coating layer 126A formed of a material (amorphous carbon) containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms. . The content of hydrogen atoms in the amorphous carbon is preferably 10 atm% or less. Moreover, it is more preferable that it is 7 atm% or less, and it is especially preferable that it is 5 atm% or less. The content of hydrogen atoms in the amorphous carbon is calculated by measuring from the coating layer 126A to a depth of 1 nm by the hydrogen forward scattering method (HFS).

(2) Carbon atom SP3 ratio In addition, the amorphous carbon has a SP3 bonded carbon atom ratio of 50% or more, more preferably 70% or more, of the carbon atoms constituting the amorphous carbon. More preferably, it is 80% or more. The SP3-bonded carbon atom ratio is calculated from the area ratio of each peak obtained by separating the peaks of the energy loss function from the electron beam energy loss spectrum connected to a transmission electron microscope (TEM).

  In order to set the hydrogen atom content to 10 atm% or less and the carbon atom SP3 ratio to 50% or more, if the coating layer 126A is formed by the FCVA apparatus, the bias and waveform of the applied voltage are changed. It can be controlled by adjusting the energy level of the ion particles.

  In the charging roll 12 according to the first embodiment, the coating layer 126A is formed directly on the surface of the elastic layer 124. However, the coating layer 126A is formed in a region sandwiched between the elastic layer 124 and the surface layer 132. If it is, it is not necessary to be formed directly on the surface of the elastic layer 124. For example, a coating layer 126A may be formed on the surface of the elastic layer 124 via a resistance adjusting layer 128, a protective layer 130, and the like, which will be described later.

  Further, the surface roughness of the layer formed in contact with the surface of the coating layer 126A on the base material 122 side, that is, the surface of the elastic layer 124 in contact with the coating layer 126A in the charging roll 12 in the first embodiment (Sm1), When the film thickness of the coating layer 126A is (T1), it is preferable to have a relationship of Sm1 ≧ T1.

Here, as a method of controlling the surface roughness of the surface of the elastic layer 124 in contact with the coating layer 126A, if the elastic layer 124 is made of the rubber material described above, the roughness of the grindstone to be polished is set. There are a method of adjusting, a method of adjusting the rotation speed and rotation direction of the rubber material and the grindstone at the time of polishing, and the like. In the case of molding without polishing, the roughness of the surface of the rubber material is controlled by previously marking the desired roughness on the inner surface of the mold for forming the rubber material. If the elastic layer 124 is made of the above-mentioned foam, a method of covering the cylindrical tube made of the above-described resin or rubber having a desired roughness on the surface of the intermediate layer to be further formed Or by controlling the foam cell diameter and density of the foam itself to adjust to a desired roughness through the intermediate layer, or by dispersing particles with the desired surface roughness in the intermediate layer, etc. Is done.
Further, when the covering layer 126A is formed on the surface of the elastic layer 124 via the resistance adjusting layer 128, the protective layer 130, or the like, the surface of the resistance adjusting layer 128 or the protective layer 130 in contact with the covering layer 126A. It is preferable to have a relationship of Sm1 ≧ T1 in relation to the surface roughness (Sm1).

The surface roughness (Sm1) of the elastic layer 124, the resistance adjusting layer 128, and the protective layer 130 is measured according to JIS B0601 (1994).
The film thickness (T1) of the coating layer 126A is measured by the following method. The elastic member is cut in the vertical direction with respect to the base material 122 on which each layer is laminated (in the case of the charging roll 12, each layer is cut in the vertical direction with respect to the base material 122), and the cut surface is The film thickness of the coating layer 126A is measured by observation with an SEM image. In addition, the measurement place is an average value of a total of nine places measured at three points (that is, three places to be cut) for each point at three points, a point 3 cm from both ends on the cut surface and a point corresponding to the center. The film thickness was obtained.

-Resistance adjustment layer and protective layer-
The surface layer 132 may be formed directly on the coating layer 126A formed on the surface of the elastic layer 124. However, the charging roll 12 in the first embodiment is provided with a resistance adjusting layer 128 for adjusting the resistance of the charging member. It is done. Furthermore, a protective layer 130 is provided from the viewpoint of preventing contamination of the surface of the member to be charged. Further, an electrode layer may be provided in a region sandwiched between the elastic layer 124 and the resistance adjusting layer 128 as necessary. The electrode layer is provided in order to disperse the concentration of current due to the presence of the conductive particles in the elastic layer 124 in an uneven manner, and is composed only of a conductive inorganic substance.

  The resistance adjustment layer 128 is provided to adjust the charging member to a predetermined resistance value, and is composed of a thin film in which the conductive particles are dispersed in a resin. Although it does not specifically limit as resin used, Resins, such as a polyurethane, polyamide, polyester, an acrylic resin, are suitable. As the conductive agent, those used for the elastic layer 124 are preferably used.

  The amount of the conductive agent added is not particularly limited. For example, in the case of an electronic conductive agent, it is preferably in the range of 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the resin used. A range of 35 parts by mass or less is more preferable.

Thus, the volume resistance value of the resistance adjustment layer 128 is preferably adjusted to a range of 3 × 10 ³ Ωcm to 5 × 10 ¹⁰ Ωcm. The thickness of the resistance adjustment layer 128 is preferably in the range of 1 μm to 500 μm, and more preferably in the range of 5 μm to 400 μm.

  The protective layer 130 further formed on the surface of the resistance adjustment layer 128 functions as a layer for preventing the charging member from adhering to the surface of the member to be charged. Furthermore, the charging member is prevented from being contaminated by the toner remaining on the surface of the body to be charged and its external additives, and the paper powder adheres to and adheres to the surface of the body to be charged. It is provided to prevent the occurrence of

  The material forming the protective layer 130 is not particularly limited, and a resin, rubber, or the like that has little contamination with respect to an object to be charged and is relatively flexible can be used. Alternatively, the protective layer 130 may be formed by forming a layer having physical properties and composition different from those of the resistance adjustment layer 128 by performing chemical treatment using UV irradiation, heat treatment, a coupling agent, or the like on the surface of the resistance adjustment layer 128.

-Surface layer-
The surface layer 132 is formed on the surface of the covering layer 126A, the resistance adjusting layer 128, or the protective layer 130 (particularly around the charging member).

  Examples of the binder resin used for the surface layer 132 include copolymer nylon and melamine crosslinked polyester. Other examples include polyester, polyamide, polyurethane, melamine resin, acrylic resin such as PMMA or PMBA, polyvinyl butyral, polyvinyl acetal, polyarylate, polycarbonate, phenoxy resin, polyurea, and polyvinyl acetate.

  Further, a conductive agent may be added to the surface layer 132, and as the conductive agent, those listed as conductive agents added to the elastic layer 124 can be applied as they are.

The surface layer 132 may contain fluorine resin particles.
Fluorine resin particles include polytetrafluoroethylene, polychlorotrifluoroethylene, polyhexafluoroethylenepropylene, polyvinylidene fluoride, polyvinyl fluoride, polydichlorodifluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetra Examples include fluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, and tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymers.

The primary particle diameter of the fluorine-based resin particles is preferably 0.05 μm or more and 1 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less, as a volume average particle diameter.
The content of the fluorine-based resin particles is preferably 1% by mass or more and 30% by mass or less of the total amount of the surface layer 132 in consideration of the overall resistance and the like.

  The charging method of the charging device may be either a method of charging the photoconductor 10 by applying a voltage in which a direct current is superimposed on an oscillating voltage such as an alternating current, or a method of charging the photoconductor 10 by applying only a DC voltage. However, the former method of applying the superimposed voltage is preferable.

(Charging roll cleaning device)
In the first image forming apparatus, a cleaning device (cleaning means) 24 provided with a cleaning blade is provided so as to be in contact with the charging roll 12. As the cleaning blade, for example, a blade formed of a conventionally known material such as SUS or a high hardness elastic body is used.

(Photoconductor)
The photosensitive member used in the first image forming apparatus has an organic photosensitive layer formed on a conductive support. The organic photosensitive layer includes at least a charge generation layer formed by binding a suitable resin containing a charge generation material as a binder (binder resin), and a charge transport layer in which the charge transport material is dispersed or dissolved in the binder resin. And an undercoat layer, a protective layer, and the like are formed as necessary. A high-hardness surface protective layer is formed on the outermost surface of the photoreceptor.

-Conductive support-
Any conductive support may be used as long as it is conventionally used.
For example, metals such as aluminum, nickel, chromium, stainless steel; plastic films provided with thin films such as aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, ITO; And paper coated with or impregnated with an agent, plastic film, and the like. Furthermore, if necessary, the surface of the conductive support can be subjected to various treatments within a range that does not affect the image quality. For example, surface anodization treatment, chemical treatment or coloring treatment, or irregular reflection treatment such as graining or liquid honing can be performed.

An undercoat layer may be formed on the surface of the conductive support as desired. The undercoat layer is an acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate In addition to polymer resin compounds such as maleic anhydride resin, silicone resin, phenol-formaldehyde resin, and melamine resin, there are organometallic compounds containing zirconium, titanium, aluminum, manganese, silicon atoms, and the like. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.
The thickness of the undercoat layer is preferably from 0.1 μm to 50 μm, and more preferably from 0.2 μm to 30 μm.

-Charge generation layer-
The charge generation layer is formed on the conductive support (when the undercoat layer is formed, on the undercoat layer).
As the charge generation material contained in the charge generation layer, phthalocyanine pigments such as metal-free phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, dichlorotin phthalocyanine, and titanyl phthalocyanine can be used. Chlorogallium phthalocyanine crystal having strong diffraction peaks at least at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° of (2θ ± 0.2 °), Bragg angle (2θ ± 0.2 °) metal-free phthalocyanine crystal having strong diffraction peaks at 7.7 °, 9.3 °, 16.9 °, 17.5 °, 22.4 ° and 28.8 °, CuKα characteristic X Bragg angle to the line (2θ ± 0.2 °) at least 7.5 °, 9.9 °, 12.5 A hydroxygallium phthalocyanine crystal having strong diffraction peaks at 16.3 °, 18.6 °, 25.1 ° and 28.3 °, a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray of at least 9. Titanyl phthalocyanine crystals having strong diffraction peaks at 6 °, 24.1 ° and 27.2 ° can be used.

In addition, as the charge generation material, a quinone pigment, a perylene pigment, an indigo pigment, a bisbenzimidazole pigment, an anthrone pigment, a quinacridone pigment, and the like can be used.
The above charge generation materials can be used alone or in admixture of two or more.

Examples of the binder resin in the charge generation layer include the following. That is, polycarbonate resin such as bisphenol A type or bisphenol Z type, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer Examples thereof include a coalescing resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, phenol-formaldehyde resin, poly-N-vinylcarbazole and the like. These binder resins can be used alone or in combination of two or more.
The compounding ratio (mass ratio) of the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10.

  As a solvent used for dispersion of the charge generating material, a solvent capable of dissolving the binder resin can be appropriately selected. As a method for dispersing the charge generating material in the resin, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a high pressure homogenizer can be used.

  Examples of the coating method include dip coating, push-up coating, spray coating, roll coater coating, and gravure coater coating. The film thickness of the charge generation layer is generally set in the range of 0.01 μm to 5 μm, preferably 0.05 μm to 2.0 μm.

-Charge transport layer-
The charge transport layer is formed on the charge generation layer.
Examples of the charge transport material include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole; 1,3,5-triphenyl-pyrazolin, 1- [ Pyrazoline derivatives such as pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazolin; triphenylamine, tri (p-methylphenyl) aminyl-4-amine, dibenzylaniline Aromatic tertiary amino compounds such as N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine etc .; 3- (4′-dimethylaminophenyl) 1,2,4-triazine derivatives such as -5,6-di- (4'-methoxyphenyl) -1,2,4-triazine; 4-diethylaminobenza Hydrazone derivatives such as rudehydr-1,1-diphenylhydrazone; quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline; benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran; p- Α-stilbene derivatives such as (2,2-diphenylvinyl) -N, N-diphenylaniline; enamine derivatives; carbazole derivatives such as N-ethylcarbazole; poly-N-vinylcarbazole and derivatives thereof; Can be mentioned.

  In addition, quinone compounds such as chloranil and broanthraquinone; tetraanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone; xanthone An electron transport material such as a compound; a thiophene compound; and the like, and a polymer having a group composed of the above-described compound in the main chain or side chain can also be exemplified. These charge transport materials can be used alone or in combination of two or more.

As the binder resin, for example, acrylic resin, polyarylate, polyester resin, bisphenol A type or bisphenol Z type polycarbonate resin; polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal Insulating resin such as polysulfone, polyacrylamide, polyamide, and chlorinated rubber (wherein insulating means outside the above-mentioned conductivity range, that is, volume resistivity is higher than 1.0 × 10 ¹³ Ωcm) And organic photoconductive polymers such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene.

  The charge transport layer may contain inorganic particles. The content of the inorganic particles in the charge transport layer is suitably from 0.1% by weight to 30% by weight, particularly preferably from 1% by weight to 20% by weight, based on the total amount of the charge transport layer.

  Examples of inorganic particles include alumina, silica, titanium oxide, zinc oxide, cerium oxide, zinc sulfide, magnesium oxide, copper sulfate, sodium carbonate, magnesium sulfate, potassium chloride, calcium chloride, sodium chloride, nickel sulfate, antimony, and dioxide. Manganese, chromium oxide, tin oxide, zirconium oxide, barium sulfate, aluminum sulfate, silicon carbide, titanium carbide, boron carbide, tungsten carbide, zirconium carbide and the like can be mentioned, and silica is preferably used. These may be used alone or in combination of two or more as required.

  The silica particles are preferably produced by chemical flame CVD, and as a specific example, produced by gas phase reaction of chlorosilane gas in a high-temperature flame of oxygen-hydrogen mixed gas or hydrocarbon-oxygen mixed gas. Is preferred.

  The inorganic particles are preferably those that have been hydrophobized with a hydrophobizing agent. As the hydrophobizing agent, for example, a siloxane compound, a silane coupling agent, a titanium coupling agent, a polymer fatty acid or a metal salt thereof is used.

Examples of the siloxane compound include dihydroxypolysiloxane and octamethylcyclotetrasiloxane.
Examples of the silane coupling agent include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N -Vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane , Dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, and the like.

  The primary particle diameter of the inorganic particles is preferably 0.005 μm or more and 2.0 μm or less, and more preferably 0.01 μm or more and 1.0 μm or less as the number average particle diameter.

  The charge transport layer can be formed by applying and drying a solution in which the charge transport material, the binder resin, the inorganic particles and the like are dissolved in an appropriate solvent.

  Examples of the solvent used for forming the charge transport layer include aromatic hydrocarbon solvents such as toluene and chlorobenzene; aliphatic alcohol solvents such as methanol, ethanol and n-butanol; acetone, cyclohexanone and 2-butanone. Ketone solvents such as; halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride; cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether; or a mixed solvent thereof Can be used.

  The blending ratio (mass ratio) of the charge transport material and the binder resin is preferably 10: 1 to 1: 5. As a method for dispersing the fluorine resin particles and further inorganic particles in the charge transport layer, it is possible to use a method such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a high-pressure homogenizer, an ultrasonic disperser, a colloid mill. it can.

  Examples of the dispersion of the coating liquid for forming the charge transport layer include a method of dispersing inorganic particles in a solution of a binder resin, a charge transport material and the like dissolved in the solvent. It is also effective to add a small amount of a dispersion aid in order to improve the dispersion stability of the dispersion and to prevent aggregation during the formation of the coating film.

  Examples of the dispersion aid include a fluorine-based surfactant, a fluorine-based polymer, a silicone-based polymer, silicone oil, and the like. From the viewpoint of high sensitivity and reduction in residual potential during repeated use, 0.1% by mass or more 1 A fluorine-based graft polymer of 0.0 mass% or less is preferably used.

  Examples of the coating method include dip coating, push-up coating, spray coating, roll coater coating, and gravure coater coating. The thickness of the charge transport layer is generally 5 μm or more and 60 μm or less, and preferably 10 μm or more and 50 μm or less. The above range is preferably selected from the viewpoint of surface abrasion resistance and charge retention performance.

-Surface protective layer-
The photoreceptor (image carrier) 10 used in the first image forming apparatus has a surface protective layer having a high hardness on the outermost surface as described above. Here, “high hardness” means that at least dynamic hardness is 13.0 × 10 ⁹ N / m or more and 100.0 × 10 ⁹ N / m or less.
The hardness is measured by the following method. The dynamic hardness has a ridge angle of 115.
A diamond indenter having a radius of curvature of 0.1 μm or less at the tip is pressed into the surface protective layer of the photoconductor 10 at a stress rate of 0.05 mN / sec. From the indentation load and the indentation depth at that time, the following formula It is calculated based on (1).
DH = 3.8854 (P / D ² ) (1)
(In the formula, DH represents dynamic hardness [N / m ² ], P represents indentation load [N], and D represents indentation depth [m].)

  Particularly preferred surface protective layers include (1) a surface protective layer containing a resin having a crosslinked structure, and (2) a surface protective layer in which inorganic particles are dispersed.

(1) Surface protective layer containing a resin having a crosslinked structure Examples of the resin having a crosslinked structure include phenolic resins, urethane resins, and siloxane resins having a crosslinked structure. In addition, it is preferable that the resin having a crosslinked structure has a charge transporting property.
Various resins are used as the resin having a cross-linked structure, and phenolic resins, urethane resins, siloxane resins, and the like are preferable in terms of characteristics, and those made of siloxane resins are more preferable.

(2) Surface protective layer in which inorganic particles are dispersed Preferable examples of the inorganic particles dispersed in the surface protective layer include alumina and titania. As a method for dispersing the inorganic particles, known methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a dyno mill, a sand mill, and a colloid mill are applied. Moreover, as an addition amount of the inorganic particle in the said surface protective layer, 0.2 to 1.0 mass% is preferable.

Other known compositions can be used.
Additives such as antioxidants, light stabilizers, and heat stabilizers in the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light or heat generated when the electrophotographic apparatus is operated. Can be added.
For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.
Examples of light stabilizers include derivatives such as benzophenone, benzoazole, dithiocarbamate, and tetramethylpipen. For the purpose of improving the surface smoothness, a leveling agent such as silicone oil can be added to the surface surface protective layer.

  The thickness of the surface protective layer is preferably 1 μm or more and 50 μm or less, and the surface roughness Rz is preferably 0.01 μm or more and 1.0 μm or less.

[Second image forming apparatus]
Next, an image forming apparatus according to the second embodiment which is a preferable aspect (referred to as “second image forming apparatus” in the present specification) will be described in detail.
The second image forming apparatus is formed on the surface of the image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and a surface of the image carrier. And developing means for developing the latent image with toner into a visible image as a toner image, and transfer means for transferring the toner image to a recording medium. The charging means is at least in contact with the substrate surface. And a coating layer formed of a coating material containing carbon atoms and having both an SP2 structure and an SP3 structure based on the carbon atoms, and having an elastic layer and a surface layer in this order on the coating layer A charging means including a member is provided.

  In other words, in the second image forming apparatus, the charging unit of the first image forming apparatus does not have a coating layer formed in a region sandwiched between the elastic layer and the surface layer, and is in contact with the substrate surface. The configuration in the image forming apparatus according to the first embodiment can be employed as it is except for the above-described features. Accordingly, in the following description, only the features and the differences from the first image forming apparatus will be described, and description of other configurations will be omitted.

(Charging device)
The charging device according to the second embodiment includes a charging member that performs charging by contacting a photoreceptor (charged body). The charging member in the second embodiment has a coating layer formed so as to be in contact with the substrate surface as described above, and an elastic layer and a surface layer on the coating layer, and the shape thereof is a roll shape. Is formed. In addition, the shape is not limited as long as it has the above-described layer structure, can stably contact with the object to be charged, and can apply a charge to the surface of the object to be charged by applying a voltage. As described in the first image forming apparatus, various shapes such as a plate shape, a block shape, and a spherical shape can be used.

  FIG. 5 shows a layer configuration of the charging roll 12 as a charging member in the second embodiment. A coating layer 126B made of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure by the carbon atoms is formed so as to be in contact with the surface of the solid columnar or hollow cylindrical base material 122. The Further, the elastic layer 124 is formed on the covering layer 126B, and the surface layer 132 as the outermost layer is formed on the elastic layer 124 via the resistance adjusting layer 128 and the protective layer 130.

-Base material-
The base material 122 can employ the base material in the first embodiment as it is.

-Coating layer-
In the charging roll 12 in the second embodiment, the coating layer 126 </ b> B is formed on the base material 122. As the coating layer 126B, the coating layer 126A described in the first embodiment can be adopted, and the formation method, preferred modes, and the like are as described above.
However, in the charging roll 12 in the second embodiment, the coating layer 126B needs to be formed so as to be in direct contact with the surface of the base material 122 without passing through another layer.

  Further, when the surface roughness of the surface of the base material 122 in contact with the coating layer 126B is (Sm2) and the film thickness of the coating layer 126B is (T2), it is preferable to have a relationship of Sm2 ≧ T2.

  Here, as a method of controlling the surface roughness of the surface in contact with the coating layer 126B of the base material 122, a method of polishing and adjusting the roughness of the grindstone to be polished, a rotation of the rubber material and the grindstone at the time of polishing There are methods for adjusting the number and direction of rotation.

The surface roughness (Sm2) of the base material 122 can be measured by employing the method for measuring the surface roughness of the elastic layer 124 described in the first embodiment.
Further, the film thickness (T2) of the coating layer 126B can also be measured by the method described in the first embodiment.

-Elastic layer, resistance adjustment layer, protective layer and surface layer-
As the elastic layer 124, the resistance adjustment layer 128, the protective layer 130, and the surface layer 132, each layer in the first embodiment can be adopted.

  As described above, in the first embodiment, the image forming apparatus including the charging member having the covering layer 126A in the region sandwiched between the elastic layer 124 and the surface layer 132 is described. In the second embodiment, the covering layer 126B is provided. The image forming apparatus including the charging member that is in contact with the base material 122 has been described. However, as a charging member used in the image forming apparatus, the first covering layer 126B is in contact with the base material 122, and the second covering layer 126A is sandwiched between the elastic layer 124 and the surface layer 132. The charging member is also used.

  Further, the image forming apparatus including the charging unit has been described as the first and second embodiments. However, on at least the base material, an elastic member having an elastic layer, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, and a surface layer in this order (that is, , An elastic member used as a charging member in the first embodiment), and a coating material that is formed so as to be in contact with at least the surface of the substrate and includes both carbon atoms and both SP2 and SP3 structures. The use of an elastic member (an elastic member used as a charging member in the second embodiment) having a coating layer formed in the above-described manner and having an elastic layer and a surface layer in this order on the coating layer It is not limited to. For example, it can be used as a transfer roll, an intermediate transfer member, a static elimination roll, and the like.

  Hereinafter, although an Example demonstrates in detail, it does not specifically limit to these Examples. In the following, “part” is based on mass unless otherwise specified.

[Example 1]
<Preparation of charging roll>
(1) Substrate As a substrate, a metal roll having a diameter (outer diameter) of 8 mm made by SUM was prepared.

(2) Elastic layer An elastic layer coating solution having the following composition was applied to the surface of the substrate and dried to form an elastic layer having a thickness of 2 mm.
・ 100 parts of rubber material (epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber,
(Gechron 3106: manufactured by Nippon Zeon)
-Conductive agent (carbon black, Asahi Thermal: Asahi Carbon Co., Ltd.) 25 parts-Conductive agent (Ketjen Black EC: Lion Corp.) 8 parts-Ionic conductive agent (lithium perchlorate) 20 parts-Vulcanizing agent (sulfur) ) 200 mesh: 1 part made by Tsurumi Chemical Industry Co., Ltd., vulcanization accelerator (Noxeller DM: made by Ouchi Shinsei Chemical Industry Co., Ltd.) 2.0 parts vulcanization accelerator (Noxeller TT: made by Ouchi Shinsei Chemical Industry Co., Ltd.) 0 .5 parts / Zinc oxide (Zinc oxide 1 type: manufactured by Shodo Chemical Industry Co., Ltd.) 5 parts The surface roughness (Sm1) of the formed elastic layer was measured by the method described above and found to be 90 .mu.m.

(3) Covering layer Using an FCVA apparatus manufactured by Shimadzu Corp., adjusting the film forming temperature, film forming speed, bias of applied voltage and waveform on the elastic layer surface, the thickness (T1) is 0.1 μm and SP3 is bonded. A Ta—C (tetrahedral amorphous carbon) layer having a carbon atom ratio of 60% to 70% was formed.

(4) Surface layer / polymer material 100 parts (copolymerized nylon, Alamine CM8000: manufactured by Toray Industries, Inc.)
-Conductive agent 14 parts (carbon black, MONARCH1000: manufactured by Cabot Corporation)
-Solvent (methanol) 500 parts-Solvent (butanol) 240 parts Dispersion A obtained by dispersing the above mixture with a bead mill was diluted with 510 parts of methanol to obtain a coating solution for conductive surface layer.

0.5 seconds after the coated surface of the coating layer is completely immersed in the conductive surface layer coating solution, V1 is set to 2 mm / s at “coating speed V = V0 + at”, and (V1 ² −V0 ² ) / V0 was set at a speed so that (2L) was −0.4 mm / s ² (where V is the coating speed, V0 is the initial speed, V1 is the final speed, and a is the acceleration. T represents time, and L represents application length).
Then, it heat-dried for 15 minutes at 140 degreeC, and formed the surface layer of thickness 8 micrometers. Thus, the charging roll of Example 1 in which the elastic layer was exposed on the surfaces at both ends in the axial direction and the shape was a roll shape was obtained.

<Production of image forming apparatus>
As an image forming apparatus having the configuration shown in FIG. 1, a color copying machine (DocuCenter Color 400CP: manufactured by Fuji Xerox Co., Ltd.) was prepared. As the charging device 12 for the photoreceptor of this image forming apparatus, the charging roll obtained as described above was mounted.
Further, on the surface of the charging roll, a standard cleaning blade arranged in a process cartridge (CRU: Customer Replaceable Unit) provided as a standard in the color copying machine (DocuCenter Color 400CP) as cleaning means 24 is shown in FIG. Are arranged as follows.

<Evaluation test: Precipitation of low molecular components on surface layer>
The charging roll was allowed to stand in an environment with a temperature of 28 ° C. and a humidity of 85% and an environment with a temperature of 45 ° C. and a humidity of 95%, respectively, and the precipitation of low molecular components on the surface of the surface layer was observed. The results are shown in Table 1 below.
-Not generated: The contact portion trace between the photoconductor and the charging roll is not visually observed, and the contact portion trace between the photoconductor and the charging roll is not printed in a white belt shape by printing. In addition, no change should be observed even if the contact area is observed with a microscope.
Minor: The contact portion trace between the photoconductor and the charging roll is visually observed, but the contact portion trace between the photoconductor and the charging roll is not printed in a white belt shape by printing.
Occurrence: The contact portion trace between the photoconductor and the charging roll is visually observed, and the contact portion trace between the photoconductor and the charging roll is printed in a white belt shape by printing. Further, when the contact portion is observed with a microscope, not only the deposits from the charging roll but also the photoconductor is cracked (however, the crack is generated only on the photoconductor having a normal charge transport layer). Therefore, if a photoconductor having a high-hardness surface protective layer is used, only precipitates are observed).
-Generation of the entire surface: In addition to the above-mentioned "occurrence" state, when the surface of the charging roll other than the contact portion with the photosensitive member is observed with a microscope, a state in which the precipitate is in a crystal form is observed.

[Example 2]
In Example 1, by changing the film thickness (T1) of the coating layer and the film thickness of the surface layer to the film thicknesses described in Table 1 below, and adjusting the roughness of the substrate surface and the film thickness of the elastic layer A charging roll and an image forming apparatus were prepared by the method described in Example 1 except that the surface roughness (Sm1) of the elastic layer was changed to the roughness described in Table 1, and an evaluation test was performed. The results are shown in Table 1 below.

Example 3
In Example 1, by changing the film thickness (T1) of the coating layer and the film thickness of the surface layer to the film thicknesses described in Table 1 below, and adjusting the roughness of the substrate surface and the film thickness of the elastic layer A charging roll and an image forming apparatus were prepared by the method described in Example 1 except that the surface roughness (Sm1) of the elastic layer was changed to the roughness described in Table 1, and an evaluation test was performed. The results are shown in Table 1 below.

Example 4
In Example 1, by changing the film thickness (T1) of the coating layer and the film thickness of the surface layer to the film thicknesses described in Table 1 below, and adjusting the roughness of the substrate surface and the film thickness of the elastic layer A charging roll and an image forming apparatus were prepared by the method described in Example 1 except that the surface roughness (Sm1) of the elastic layer was changed to the roughness described in Table 1, and an evaluation test was performed. The results are shown in Table 1 below.

Example 5
In Example 1, by changing the film thickness (T1) of the coating layer and the film thickness of the surface layer to the film thicknesses described in Table 1 below, and adjusting the roughness of the substrate surface and the film thickness of the elastic layer A charging roll and an image forming apparatus were prepared by the method described in Example 1 except that the surface roughness (Sm1) of the elastic layer was changed to the roughness described in Table 1, and an evaluation test was performed. The results are shown in Table 1 below.

[Comparative Example 1]
In Example 1, a charging roll and an image forming apparatus were prepared by the method described in Example 1 except that the surface layer was provided directly on the elastic layer without providing the coating layer on the elastic layer, and the evaluation test was performed. (The surface roughness (Sm1) of the elastic layer is as shown in Table 1). The results are shown in Table 1 below.

[Comparative Example 2]
In Example 2, a charging roll and an image forming apparatus were prepared by the method described in Example 2 except that a surface layer was provided directly on the elastic layer without providing a coating layer on the elastic layer, and an evaluation test was performed. (The surface roughness (Sm1) of the elastic layer is as shown in Table 1). The results are shown in Table 1 below.

[Comparative Example 3]
In Example 3, a charging roll and an image forming apparatus were prepared by the method described in Example 3 except that a surface layer was provided directly on the elastic layer without providing a coating layer on the elastic layer, and an evaluation test was performed. (The surface roughness (Sm1) of the elastic layer is as shown in Table 1). The results are shown in Table 1 below.

[Comparative Example 4]
In Example 4, a charging roll and an image forming apparatus were prepared by the method described in Example 4 except that a surface layer was provided directly on the elastic layer without providing a coating layer on the elastic layer, and an evaluation test was performed. (The surface roughness (Sm1) of the elastic layer is as shown in Table 1). The results are shown in Table 1 below.

[Comparative Example 5]
In Example 5, a charging roll and an image forming apparatus were prepared by the method described in Example 5 except that a surface layer was provided directly on the elastic layer without providing a coating layer on the elastic layer, and an evaluation test was performed. (The surface roughness (Sm1) of the elastic layer is as shown in Table 1). The results are shown in Table 1 below.

In the evaluation tests of Examples 1 to 5, the elastic layer did not swell.
Further, when 25,000 sample print tests were performed using the image forming apparatuses obtained in Examples 1 to 5, there was no occurrence of peeling of the coating layer, and the low deposition amount from the elastic layer. The occurrence of filming on the surface of the photoreceptor due to molecular components was not found.

Example 6
<Preparation of charging roll>
(a) Base material As a base material, a metal roll having a diameter (outer diameter) of 8 mm made by SUM was prepared.
In addition, it was 61.5 micrometers when the surface roughness (Sm2) of the formed base material was measured by the above-mentioned method.

(b) Coating layer Using a FCVA apparatus manufactured by Shimadzu Corporation, the film forming temperature, film forming speed, bias of applied voltage and waveform are adjusted on the base material surface, and the thickness (T2) is 0.05 μm and SP3 is bonded. A Ta—C (tetrahedral amorphous carbon) layer having a carbon atom ratio of 60% to 70% was formed.

(c) Elastic layer An elastic layer coating solution having the following composition was applied to the surface of the coating layer and dried to form an elastic layer having a thickness of 2 mm.
・ 100 parts of rubber material (epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber,
(Gechron 3106: manufactured by Nippon Zeon)
-Conductive agent (carbon black, Asahi Thermal: Asahi Carbon Co., Ltd.) 25 parts-Conductive agent (Ketjen Black EC: Lion Corp.) 8 parts-Ionic conductive agent (lithium perchlorate) 20 parts-Vulcanizing agent (sulfur) ) 200 mesh: 1 part made by Tsurumi Chemical Industry Co., Ltd., vulcanization accelerator (Noxeller DM: made by Ouchi Shinsei Chemical Industry Co., Ltd.) 2.0 parts vulcanization accelerator (Noxeller TT: made by Ouchi Shinsei Chemical Industry Co., Ltd.) 0 .5 parts-Zinc oxide (Zinc oxide 1 type: manufactured by Shodo Chemical Industry Co., Ltd.) 5 parts

(d) 100 parts of surface layer / polymer material (copolymerized nylon, Alamine CM8000: manufactured by Toray Industries, Inc.)
-Conductive agent 14 parts (carbon black, MONARCH1000: manufactured by Cabot Corporation)
-Solvent (methanol) 500 parts-Solvent (butanol) 240 parts Dispersion A obtained by dispersing the above mixture with a bead mill was diluted with 510 parts of methanol to obtain a coating solution for conductive surface layer.

0.5 seconds after the coated surface of the elastic layer is completely immersed in the coating solution for the conductive surface layer, V1 is set to 2 mm / s at “coating speed V = V0 + at”, and (V1 ² −V0 ² ) / V0 was set at a speed so that (2L) was −0.4 mm / s ² (where V is the coating speed, V0 is the initial speed, V1 is the final speed, and a is the acceleration. T represents time, and L represents application length).
Then, it heat-dried for 15 minutes at 140 degreeC, and formed the surface layer of thickness 8 micrometers. Thus, the charging roll of Example 6 in which the elastic layer was exposed on the surfaces at both ends in the axial direction and the shape was a roll shape was obtained.

<Production of image forming apparatus>
A color copying machine (Docucenter Color 400CP: manufactured by Fuji Xerox Co., Ltd.) was prepared as the image forming apparatus having the configuration shown in FIG.

<Evaluation test: Occurrence of protrusions on the surface of the surface layer>
The charging roll was left in an environment of a temperature of 28 ° C. and a humidity of 85% and an environment of a temperature of 45 ° C. and a humidity of 95%, and the occurrence of blisters (convex portions) on the surface of the surface layer was observed and evaluated according to the following criteria. The results are shown in Table 2 below.
・ Non-occurrence: Surface blistering is not observed even after visual inspection.
・ Occurrence (numerical value): Surface blistering is observed by visual inspection, but even if the height of blistering is measured with a surface roughness measuring device (SURFCOM, manufactured by Tokyo Seimitsu), it is 5 μm or more and 15 μm or less. There is. Furthermore, no blisters are printed even when halftones of 30% and 50% are printed with the above copying machine.
Occurrence: The appearance of the bulge is observed by visual inspection, and the bulge height measured by the surface roughness measuring device SURFCOM is 10 μm or more, but the number is less than 20 in one charging roll. Furthermore, when 30% and 50% halftones are printed by the copying machine, the blisters are printed as white circular missing prints.
・ Overall generation: The appearance of the blister is observed by visual inspection, and when the height of the blister is measured by the surface roughness measuring device SURFCOM, it is 10 μm or more, and the number is 20 or more in one charging roll. In addition, the size (width) of each blister is 5 mm or more. Furthermore, when 30% and 50% halftones are printed by the copying machine, the blisters are printed as white circular missing prints.

Example 7
In Example 6, the thickness of the coating layer (T2) and the surface roughness (Sm2) of the base material were changed so as to be those shown in Table 2 below. An image forming apparatus was manufactured and an evaluation test was performed. The results are shown in Table 2 below.

Example 8
In Example 6, the thickness of the coating layer (T2) and the surface roughness (Sm2) of the base material were changed so as to be those shown in Table 2 below. An image forming apparatus was manufactured and an evaluation test was performed. The results are shown in Table 2 below.

Example 9
In Example 6, the thickness of the coating layer (T2) and the surface roughness (Sm2) of the base material were changed so as to be those shown in Table 2 below. An image forming apparatus was manufactured and an evaluation test was performed. The results are shown in Table 2 below.

Example 10
In Example 6, the thickness of the coating layer (T2) and the surface roughness (Sm2) of the base material were changed so as to be those shown in Table 2 below. An image forming apparatus was manufactured and an evaluation test was performed. The results are shown in Table 2 below.

[Comparative Example 6]
In Example 6, a charging roll and an image forming apparatus were prepared by the method described in Example 6 except that the elastic layer was directly provided on the substrate without providing the coating layer on the substrate, and an evaluation test was performed. (The surface roughness (Sm2) of the base material is as shown in Table 2). The results are shown in Table 2 below.

[Comparative Example 7]
In Example 7, a charging roll and an image forming apparatus were produced by the method described in Example 7 except that the elastic layer was directly provided on the base material without providing the coating layer on the base material. (The surface roughness (Sm2) of the base material is as shown in Table 2). The results are shown in Table 2 below.

[Comparative Example 8]
In Example 8, a charging roll and an image forming apparatus were prepared by the method described in Example 8 except that the elastic layer was directly provided on the substrate without providing the coating layer on the substrate, and an evaluation test was performed. (The surface roughness (Sm2) of the base material is as shown in Table 2). The results are shown in Table 2 below.

[Comparative Example 9]
In Example 9, a charging roll and an image forming apparatus were prepared by the method described in Example 9 except that the elastic layer was directly provided on the substrate without providing the coating layer on the substrate, and an evaluation test was performed. (The surface roughness (Sm2) of the base material is as shown in Table 2). The results are shown in Table 2 below.

[Comparative Example 10]
In Example 10, a charging roll and an image forming apparatus were prepared by the method described in Example 10 except that the elastic layer was directly provided on the substrate without providing the coating layer on the substrate, and an evaluation test was performed. (The surface roughness (Sm2) of the base material is as shown in Table 2). The results are shown in Table 2 below.

1 is a configuration diagram illustrating an example of an image forming apparatus according to first and second embodiments. FIG. 2 is a cross-sectional view illustrating a layer configuration of a charging roll provided in the image forming apparatus according to the first embodiment. It is explanatory drawing which shows the classification | category by the difference in the crystal structure of carbon. It is a conceptual diagram explaining an FCVA apparatus. FIG. 6 is a cross-sectional view illustrating a layer configuration of a charging roll provided in an image forming apparatus according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photoconductor 12 Charging roll 14 Exposure apparatus 16 Developing apparatus 18 Cleaning apparatus 20 Transfer roll 22 Transfer material 24 Charging roll cleaning apparatus 40 Carbon ion generation source 41 Cathode 42 Anode 43 Filter 44 Magnetic coil 122 Base material 124 Elastic layers 126A and 126B Coating layer 128 Resistance adjustment layer 130 Protective layer 132 Surface layer

Claims (14)

On at least the base material, an elastic layer, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, and a surface layer containing a resin and a conductive agent in this order An elastic member for an image forming apparatus, comprising:   When the surface roughness of the surface in contact with the coating layer in the layer formed in contact with the substrate side surface of the coating layer is (Sm1) and the film thickness of the coating layer is (T1), Sm1 ≧ T1 The elastic member for an image forming apparatus according to claim 1, wherein the elastic member has a relationship.   The elastic member for an image forming apparatus according to claim 1, wherein the elastic layer has a region exposed on a surface.   A coating layer formed of a coating material which is formed so as to be in contact with at least the substrate surface and includes carbon atoms, and which has both the SP2 structure and the SP3 structure based on the carbon atoms, and an elastic layer and a surface layer on the coating layer And an elastic member for an image forming apparatus.   The surface roughness of the surface which contacts the coating layer of the said base material is set to (Sm2) and the film thickness of the said coating layer is set to (T2), It has a relationship of Sm2> = T2. Elastic member for image forming apparatus.   A first coating layer formed of a coating material which is formed so as to be in contact with at least the surface of the substrate and includes carbon atoms and which has both the SP2 structure and the SP3 structure based on the carbon atoms; 2. An elastic layer, a second coating layer formed of a coating material containing carbon atoms and having both an SP2 structure and an SP3 structure based on the carbon atoms, and a surface layer in this order. The elastic member for an image forming apparatus according to claim 5. On at least the base material, an elastic layer, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure based on the carbon atoms, and a surface layer containing a resin and a conductive agent in this order A charging member having
A charging device for an image forming apparatus, wherein a charged body is charged by the charging member.   The charging device for an image forming apparatus according to claim 7, wherein the charging member has a roll shape.   The charging device for an image forming apparatus according to claim 7, further comprising a cleaning unit that contacts and cleans the surface of the charging member. A coating layer formed of a coating material which is formed so as to be in contact with at least the substrate surface and includes carbon atoms, and which has both the SP2 structure and the SP3 structure based on the carbon atoms, and an elastic layer and a surface layer on the coating layer And a charging member having in this order,
A charging device for an image forming apparatus, wherein a charged body is charged by the charging member.   The charging device for an image forming apparatus according to claim 10, wherein the charging member has a roll shape. An image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and a latent image formed on the surface of the image carrier is developed with toner. A developing unit that visualizes the toner image; and a transfer unit that transfers the toner image to a recording medium.
As the charging means, on at least a base material, an elastic layer, a coating layer formed of a coating material containing carbon atoms and having both the SP2 structure and the SP3 structure by the carbon atoms , a surface layer containing a resin and a conductive agent And an image forming apparatus using a charging unit including a charging member having the above-mentioned order.   The image forming apparatus according to claim 12, wherein the image carrier has a high-hardness surface protective layer. An image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and a latent image formed on the surface of the image carrier is developed with toner. A developing unit that visualizes the toner image; and a transfer unit that transfers the toner image to a recording medium.
The charging means has a coating layer formed of a coating material which is formed so as to be in contact with at least the surface of the base material and includes carbon atoms and which has both the SP2 structure and the SP3 structure based on the carbon atoms, on the coating layer An image forming apparatus using a charging unit including a charging member having an elastic layer and a surface layer in this order.