JP2003162105A - Electrophotographic roller and image forming device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide, at a low cost, an electrophotographic roller that restricts electrifying noise, extremely reduces image carrier wear, ensures sufficient nip width despite a small diameter, and is excellent in electrifying stability and an image forming device using the electrophotographic roller. <P>SOLUTION: In the electrophotographic roller, a conductive elastic layer 14 formed from a three-dimensional mesh structure is formed on the periphery of a metal shaft 12 and, further, a semi-conductive elastic layer 16 is formed on the periphery of the conductive elastic layer 14. The image forming device uses the electrophotographic roller. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic roller which can be used in an electrophotographic apparatus utilizing an electrophotographic process such as a copying machine, a printer and a facsimile, and an image forming apparatus equipped with the electrophotographic roller.

Here, the electrophotographic roller in the present invention is a conductive or semiconductive roller such as a charging roller, a transfer roller, a primary transfer roller and a secondary transfer roller in an intermediate transfer system, and is photosensitive. It is used in contact with or close to an image carrier such as a body or an intermediate transfer body. The image carrier and the intermediate transfer member may be any of a drum-shaped body, a belt-shaped body, and a shape corresponding to them.

[0003]

2. Description of the Related Art Conventionally, most of electrophotographic image forming apparatuses employ a contact charging and contact transfer method in which generation of ozone, which is considered to be harmful, is extremely small. A roller-shaped member, which is excellent in transfer material transportability, has become the mainstream. Most of the roller-shaped members are made of an elastic material and can surely form a nip with respect to the image carrier such as the photoconductor or the intermediate transfer member.

These rollers generally have a resistance of 1 × 10 ⁵ to 1 × 10 ¹² on a core metal such as stainless steel (SUS) or Fe by carbon black, an ion conductive agent or the like.
A semiconductive elastic roller having a resistance of about [Ω] is used.

[0005]

In recent years, the image forming apparatus is required to be quiet, and in particular, when a high-frequency AC voltage is superposed on a DC voltage as a charging device, image uniformity is improved. Although it is excellent, the so-called charging noise generated by the charging roller is an unpleasant sensation to the ear and is a major technical problem.

As a method for preventing this charging noise, a method has been proposed in which a weight is placed in an image carrier (especially a photoconductor) to prevent high frequency vibration transmission from the charging roller. A member and a step of fixing (adhering) it in the image bearing member (photoreceptor) are newly required, which inevitably results in cost increase. Also, as another method of preventing charging noise, a method of providing a foam layer on the charging roller and absorbing the vibration is also adopted, but with the foam layer alone, a non-uniform charging state according to the unevenness of the surface is obtained, and it becomes uniform. It is difficult to obtain a good image.

On the other hand, in recent years, there is a strong demand for downsizing of the image forming apparatus, and accordingly, downsizing of the charging device is also required. In a charging device using a roll type charging member,
Miniaturization means reduction in the diameter of the roll, and it becomes difficult to secure the contact area (nip width) with the image carrier as the diameter of the roll decreases. Further, when the contact area becomes small, it becomes difficult to stabilize the contact area during running (uniform nip width), which also affects the charging stability.

Furthermore, in recent years, in order to reduce the unit cost of printing or copying (so-called running cost reduction), it is required to extend the life of the image bearing member (especially the photoreceptor). As described above, when a high-frequency AC voltage is superposed on a DC voltage as the charging device, the image carrier (especially the photoconductor) is discharged by a small gap between the image carrier (especially the photoconductor) and the charging roller. The surface of the photoconductor is easily scraped (so-called etching action), and the life of the image carrier (particularly the photoconductor) is largely controlled.

As a measure against the charging noise and abrasion of the image bearing member (especially the photosensitive member), so-called DC charging in which only a DC voltage is applied to the charging roller has been proposed. However, in order to enable uniform charging by DC charging, the charging roller is required to have high resistance uniformity and excellent surface smoothness.

This means that, as described above, in DC charging, the resistance change due to the adhesion of dirt to the surface of the charging roller and the environmental change greatly affects the image.
In addition, since a voltage of the same polarity is always applied in DC charging, in a resistance material, particularly an ion conductive resistance material, polar groups are polarized, and it is difficult for current to flow, so-called charge-up is likely to occur. There is also a problem to say.

Although the conventional problems have been described above by taking the charging roller as an example, various electrophotographic rollers for the purpose of charging and transferring also have the same problems as the above problems to some extent. Had.

Therefore, in view of the above-mentioned problems, the present invention suppresses the generation of charging noise, reduces the abrasion of the image carrier extremely, and secures a sufficient nip width even with a small diameter. An object of the present invention is to provide an electrophotographic roller having excellent properties and an image forming apparatus using the same at low cost.

[0013]

The above object can be achieved by the present invention described below. That is, the present invention provides that <1> a conductive elastic layer having a three-dimensional mesh structure is formed on the outer circumference of a metal shaft, and a semiconductive elastic layer is further formed on the outer circumference of the conductive elastic layer. It is a characteristic electrophotographic roller.

<2> 10V in the conductive elastic layer
The electric resistance when applied is 9 × 10 ⁴ Ω or less, and the electric resistance when 100 V is applied to the semiconductive elastic layer is 1 × 1.
The electrophotographic roller according to <1>, which has a resistance of 0 ⁴ Ω to 1 × 10 ¹⁰ Ω.

<3> The shortest distance between skeletons in the three-dimensional network structure of the conductive elastic layer is 200 μm or more,
The electrophotographic roller according to <1> or <2>, wherein the skeleton has a thickness of 1000 μm or less.

<4> The semiconductive elastic layer has a thickness of 10
<1> to <, wherein the semi-conductive elastic layer has a micro rubber hardness of 70 ° or less.
The roller for electrophotography according to any one of 3>.

<5> The semiconductive elastic layer is a seamless tube composed of one or more layers and one or more materials. <1> to <4> This is a roller for electrophotography.

<6> A conductive adhesive layer is formed on the outer periphery of the metal shaft, the conductive elastic layer is formed on the conductive adhesive layer, and a conductive adhesive is applied on the conductive elastic layer. The electrophotographic roller according to any one of <1> to <5>, wherein the semiconductive elastic layer is formed.

<7> The conductive elastic layer and the semiconductive elastic layer are each formed as a seamless tube, and are sequentially laminated on the outer circumference of the metal shaft using a conductive adhesive. <1> to <5
The roller for electrophotography according to any one of <1>.

<8> The conductive elastic layer and the semiconductive elastic layer are simultaneously formed as a seamless tube,
The roller for electrophotography according to any one of <1> to <5>, wherein the roller is bonded to the outer circumference of the metal shaft via a conductive adhesive.

<9> A charging member which contacts the surface of the image carrier and charges the surface of the image carrier <1.
> To <8>, the electrophotographic roller according to any one of items.

<10> The electrophotographic roller according to any one of <1> to <8>, which is a transfer member for transferring the toner image formed on the surface of the image carrier to a transfer material. Is.

<11> At least an image carrier and a charging member in contact with the image carrier are provided. Prior to forming an electrostatic latent image, a voltage is applied to the charging member while the charging member and the image carrier are carried. An image forming apparatus including a structure for charging the surface of the image carrier by rotating the body and the body, respectively, wherein the charging member is the electrophotographic roller according to <9>. The image forming apparatus.

<12> The image forming apparatus according to <10>, wherein the charging member and the image carrier have a peripheral speed difference.

<13> The voltage applied to the charging member is a DC voltage <10> or <
11> is an image forming apparatus.

<14> At least an image carrier on the surface of which a toner image is formed by a predetermined means, and a transfer member which contacts the image carrier to form a nip portion, and the transfer material is inserted into the nip portion. And a transfer member is the electrophotographic roller according to <10>, wherein the transfer member is a roller for electrophotography, which forms a image by transferring the toner image on the surface of the image carrier to the transfer material. And an image forming apparatus.

<15> At least an image carrier on which a toner image is formed on the surface by a predetermined means, and a primary transfer means for transferring the toner image on the surface of the image carrier to an intermediate transfer body,
An image forming apparatus comprising: a secondary transfer unit that transfers the toner image on the surface of the intermediate transfer member to a transfer material, wherein the primary transfer unit and / or the secondary transfer unit are <1> to
An image forming apparatus, which is the electrophotographic roller according to any one of <8>.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A: Electrophotographic Roller Hereinafter, the electrophotographic roller of the present invention will be described in detail with reference to the drawings with reference to embodiments.

FIG. 1 is a schematic diagram showing an example of the electrophotographic roller of the present invention. FIG. 1 (A) is a longitudinal sectional view, and FIG. 1 (B) is A- in FIG. 1 (A). FIG. As shown in FIG. 1, in an electrophotographic roller 10 which is an example of the present invention, a conductive elastic layer 14 having a three-dimensional mesh structure is formed on the outer periphery of a metal shaft 12, and the conductive elastic layer 14 is further formed. The semiconductive elastic layer 16 is formed on the outer periphery. Hereinafter, each layer will be described in detail.

<Conductive Elastic Layer> First, the conductive elastic layer 14 having a three-dimensional mesh structure will be described. In the present invention, the “three-dimensional mesh structure” is composed of skeletons in which three-dimensional meshes are formed and spaces existing between the skeletons,
The space is not divided by the skeleton and is in a state of communicating with each other. Therefore, in a so-called foamed body having a large number of cells inside the structure, the individual cells are generally independent, and the cells are not partitioned by the membrane so as to communicate with each other. It is not included in the concept of “dimensional mesh structure”.

In the present invention, the shortest distance between the skeletons of the three-dimensional network structure is preferably 200 μm or more, more preferably 300 to 700 μm. Further, the thickness of the skeleton is preferably 1000 μm or less, and more preferably 50 to 300 μm. With such a structure, it is possible to realize a conductive elastic layer having an ultra-low hardness, which cannot be realized by a conventional foam such as sponge.

When the shortest distance between the skeletons of the three-dimensional network structure in the conductive elastic layer 14 is less than 200 μm, the conductive elastic layer 14 becomes hard and the desired ultra-low hardness may not be exhibited. In addition, 3 in the conductive elastic layer 14
Even if the thickness of the skeleton of the three-dimensional network structure exceeds 1000 μm, the conductive elastic layer 14 may become hard and the desired ultra-low hardness may not be exhibited.

The term "shortest distance between skeletons" as used herein refers to two skeletons connected via two or more branch points and facing each other, or an independent skeleton having no direct connection. It means the shortest distance between each other. Further, the skeleton may be thicker around the branch point, but the “thickness of the skeleton” is a discussion of a portion having an average thickness other than around the branch point.

Since the conductive elastic layer 14 having the three-dimensional network structure as described above has an extremely low hardness, the semiconductive elastic layer 16 is used.
The electrophotographic roller 10 can be freely deformed even after being coated, and the nip width with the image carrier or the intermediate transfer body when used as a charging roll or a transfer roll can always be kept uniform. It will be possible.

Further, since the conductive elastic layer 14 having a three-dimensional mesh structure has an ultra-low hardness as described above, even when the outer diameter of the electrophotographic roller 10 to be obtained is made smaller than that of the conventional one, the central portion of the roller can be reduced. It is possible to secure a uniform nip width without floating.

Further, since the conductive elastic layer 14 having a three-dimensional mesh structure has an extremely low hardness as described above, the obtained electrophotographic roller 10 is used as a charging roll, and a high-frequency alternating voltage is superposed on a direct-current voltage. In this case, the vibration at the time of charging can be sufficiently absorbed, the charging noise can be suppressed, and the stress on the image carrier is small, so that the surface of the image carrier (especially the photoconductor) is not worn. Can also be reduced.

The conductive elastic layer 14 has a three-dimensional network structure formed of a binder material, and a conductive material is mixed or applied to the conductive elastic layer 14 so that the conductive elastic layer 14 as a whole exhibits conductivity.

Most of the conventional electrophotographic rollers are provided with an elastic layer whose resistance is adjusted to some extent on the outer circumference of a metal shaft, a semiconductive layer called an intermediate layer on the outer circumference, and a surface layer on the outer circumference. Multilayer construction was common. In addition to this, there was also a simple structure in which a resistance layer was provided on the outer circumference of the metal shaft and a surface layer was provided on the outer circumference, but in each case, a layer having a certain degree of resistance occupied most of the roller. Therefore, it is difficult to suppress the resistance variation, and particularly when it is used as a charging member of a system in which only a DC voltage is applied, there is a drawback that an image defect due to resistance unevenness is likely to occur.

In the present invention, in order to eliminate the above variations in resistance, the semiconductive elastic layer 1 is provided with a layer having resistance.
No. 6 is used, and the other layers have a structure in which electric resistance is close to zero. Therefore, according to the roller for electrophotography of the present invention, it is possible to provide a charging member having less variation in resistance and excellent charging stability.
In particular, in the charging member of the type in which only a DC voltage is applied, it is desired to eliminate the variation in the electric resistance of the entire electrophotographic roller in a higher dimension, and therefore the electrophotographic roller of the present invention is preferably used.

As a binder material for forming the conductive elastic layer 14, SBR (styrene-butadiene rubber), BR
(Polybutadiene rubber), High styrene rubber (Hi S
Tyrene resin masterbatc
h), IR (isoprene rubber), IIR (butyl rubber), halogenated butyl rubber (Halogenated)
butyrrubber), NBR (nitrile butadiene rubber), hydrogenated NBR (H-NBR), EPDM,
EPM (ethylene propylene rubber), NBR / EPDM
Blend, CR (chloroprene rubber), ACM (acrylic rubber), CO (hydrin rubber), ECO (epichlorohydrin rubber), chlorinated polyethylene (Chlorin
aated-PE), VAMAC (ethylene-acrylic rubber), VMQ (silicone rubber), U (urethane rubber), FKM (fluorine rubber), NR (natural rubber), CS
Rubber materials such as M (chlorosulphonated polyethylene rubber);

PVC (polyvinyl chloride), polyethylene, polypropylene, polystyrene, polyester, polyurethane, polyamide, polyimide, nylon, ethylene vinyl acetate, ethylene ethyl acrylate, ethylene methyl acrylate, styrene butadiene, polyarylate, polycarbonate, fluororesin, Silicone resin, polymethacrylate, polybutylmethacrylate,
Resin materials such as polyvinyl acetate, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin and phenol resin;

A homopolymer of styrene such as polystyrene and polyvinyltoluene and its substitution products, for example, styrene-
Propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-acrylic Octyl acid acid copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminomethacrylate Ethyl copolymer,
Styrene-vinyl methyl ether copolymer, styrene-
Styrene type such as vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer A copolymer;

In addition, the binder material is selected from various resins such as aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, paraffin wax, carnauba wax, mixtures thereof, copolymers and modified products thereof. It may be The binder material is not limited to the above examples.

By using a binder material selected from the above material group and selecting one of the following methods, a layer having a three-dimensional network structure can be formed. A method in which the binder material is dissolved in an appropriate solvent and then foamed with a stirrer and then molded into a predetermined shape. A method in which a foaming agent is kneaded into the binder material, and then molded into a predetermined shape and heat-foamed. A method in which the binder material is kneaded with a component soluble only in a specific solvent, shaped into a predetermined shape and then immersed in the specific solvent to dissolve the component, and only the part of the binder material which is not dissolved is left.

At this time, in order to impart conductivity to the layer composed of the three-dimensional network structure, (1) in molding the layer,
A method of imparting conductivity by previously mixing a conductive material with each material (solution, kneaded material, etc.), (2) Dispersing and / or dissolving the conductive material after molding into a predetermined shape. The conductive coating or the conductive adhesive may be dipped in or sprayed with the conductive coating to subsequently impart conductivity, and the like. In the present invention, any method is used. May exhibit conductivity.

The conductive material that can be used here is not particularly limited. For example, carbon-based magnetic powder such as carbon black and graphite; metal powder such as tin, iron and copper; metal fiber; A mixture of: metal oxides such as zinc oxide, tin oxide and titanium oxide; metal sulfides such as copper sulfide and zinc sulfide; so-called hard ferrites such as strontium, barium and rare earths; magnetite, copper, zinc, nickel and manganese Ferrite or those whose surface is subjected to conductive treatment as necessary; copper, iron, manganese,
Nickel, zinc, cobalt, barium, aluminum,
A solid solution of a metal oxide (so-called composite) selected from oxides, hydroxides, carbonates or metal compounds containing different metal elements such as tin, lithium, magnesium, silicon and phosphorus, and obtained by firing at high temperature. Metal oxide); and the like. Further, an ionic conductive agent such as a quaternary ammonium salt or a metal substitution product of a quaternary ammonium salt may be used. These conductive materials may be used alone or in combination of two or more kinds. Further, examples of the conductive adhesive that can be used for imparting conductivity include those described below.

The conductive elastic layer 14 is formed by dissolving (a) a precursor of the conductive elastic layer made of the above-mentioned materials (for example, the binder material and a conductive material added as necessary in a suitable solvent). And / or a liquid obtained by dispersion; a kneaded product of the binder material and a conductive material, a foaming agent, or the like added as necessary; the binder material, a conductive material added as necessary, or a specific material A kneaded product with a component that is soluble only in a solvent, etc. (hereinafter, simply referred to as "conductive elastic layer precursor") A method of forming by directly applying to the outer periphery of the metal shaft 12, (b) the metal shaft 12 A method of pouring a conductive elastic layer precursor into a cylindrical mold arranged at an axis, and (c) a suitable shape (a rectangular parallelepiped shape, a large cylindrical shape, etc.) in which the metal shaft 12 is arranged at or near the axis. ) On the formwork After the electroelastic layer precursor is cast and molded, a method of forming by grinding to a desired diameter while rotating the metal shaft 12 as an axis, and (d) separately molding the conductive elastic layer precursor into a seamless tube shape It can be formed on the outer circumference of the metal shaft by a method of externally mounting it on the metal shaft 12.

Whichever method is used, in order to make the joint between the metal shaft 12 and the conductive elastic layer 14 stronger, the space between the metal shaft 12 and the conductive elastic layer 14 is increased. It is desirable that a conductive adhesive layer (not shown) is formed on the. The conductive adhesive layer is formed
It is performed by applying a conductive adhesive to the surface of the metal shaft 12. Examples of the conductive adhesive include conductive adhesives such as conductive binders such as urethane, polyester, nylon, and epoxy resin, in which conductive carbon or metal powder is dispersed and dissolved in a solvent. The thickness of the conductive adhesive layer is not particularly limited, but it is 1 to 20 μm.
A degree is preferable. Also, 100 V in the conductive adhesive layer
The electric resistance when applied is preferably 10 ³ Ω or less. The method of applying the conductive adhesive may be any of spraying, spray coating, dip coating, brush coating and the like.

In the present invention, the conductive elastic layer 14 has a sufficient ultra-low hardness to exert the above-mentioned effects such as the nip width and the reduction of the abrasion of the surface of the image bearing member (especially the photosensitive member). In order to realize the miniaturization of the device, the thickness is preferably about 1 to 5 mm, more preferably about 2 to 4 mm. For the same reason, the conductive elastic layer 1
The hardness of 4 is preferably 20 ° or less when measured by an Asker-C hardness meter.

In the present invention, the conductive elastic layer 14 preferably has an electric resistance of 9 × 10 ⁴ Ω or less when 10 V is applied. As described above, in the charging member of the type in which only the DC voltage is applied, it is desired to eliminate the variation in the electric resistance of the entire electrophotographic roller in a higher dimension. Therefore, the conductive elastic layer 14 should be as electrically conductive as possible. It is desirable to keep the resistance low. If the electric resistance of the conductive elastic layer 14 when 10 V is applied is 9 × 10 ⁴ Ω or less, the electric resistance is practically zero when a direct current voltage of several hundred to several thousand volts applied in actual use is applied. It is preferable because it is close to. 1 in the conductive elastic layer 14
The electric resistance when 0 V is applied is more preferably 1 × 10 ⁴ Ω or less.

A method for measuring the electric resistance of the conductive elastic layer 14 when 10 V is applied will be described. As shown in FIG. 2, the conductive roll 20 in which only the conductive elastic layer 14 is formed on the metal shaft 12 is placed on a flat plate 22 made of metal (preferably stainless steel), and the metal shaft 12 and the flat plate A direct current voltage of 10 V is applied between the power source device 24 and 22 and the current value of the ammeter 26 is read to measure the electric resistance between the metal shaft 12 and the flat plate 22, and the electric resistance is measured. The electric resistance of the layer 14 was measured when 10 V was applied.

<Semiconductive Elastic Layer> Next, the semiconductive elastic layer 16 will be described. As the semiconductive elastic layer 16, the known mode which has been conventionally adopted as the semiconductive elastic layer of the charging roll can be directly adopted. Specifically, it is composed of at least a binder material, and a resistance adjusting agent for adjusting the electric resistance within a predetermined range and other additives are added as necessary.

As the binder material for forming the semiconductive elastic layer 16, SBR (styrene-butadiene rubber), B
R (polybutadiene rubber), high styrene rubber (Hi
Stylene resin masterbatc
h), IR (isoprene rubber), IIR (butyl rubber), halogenated butyl rubber (Halogenated)
butyrrubber), NBR (nitrile butadiene rubber), hydrogenated NBR (H-NBR), EPDM,
EPM (ethylene propylene rubber), NBR / EPDM
Blend, CR (chloroprene rubber), ACM (acrylic rubber), CO (hydrin rubber), ECO (epichlorohydrin rubber), chlorinated polyethylene (Chlorin
aated-PE), VAMAC (ethylene-acrylic rubber), VMQ (silicone rubber), U (urethane rubber), FKM (fluorine rubber), NR (natural rubber), CS
Rubber materials such as M (chlorosulphonated polyethylene rubber);

PVC (polyvinyl chloride), polyethylene, polypropylene, polystyrene, polyester, polyurethane, polyamide, polyimide, nylon, ethylene vinyl acetate, ethylene ethyl acrylate, ethylene methyl acrylate, styrene butadiene, polyarylate, polycarbonate, fluororesin, Silicone resin, polymethacrylate, polybutylmethacrylate,
An elastomer copolymerized or modified from resins such as polyvinyl acetate, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, and phenol resin can be used.

Each of the above materials is preferably selected from materials that do not contain a component such as a low molecular weight component or a plasticizer that precipitates on the surface (so-called bleeding). However, if there is a concern that low molecular weight components, plasticizers, etc. may precipitate on the surface (so-called bleeding), there is no problem even if appropriate surface treatment is performed or surface coating is applied to prevent precipitation (so-called bleeding). Absent.

The above-mentioned various binder materials may be used alone or by kneading a resistance adjusting agent to adjust the electric resistance within a predetermined range, and then molding into a seamless tube, which is then formed into a conductive elastic layer 1.
4 or the conductive elastic layer 14
The semiconductive elastic layer 16 is formed by directly applying to the outer periphery of the. The specific forming method is the same as that of the conductive elastic layer 14.

The resistance adjusting agent used for adjusting the electric resistance of the semiconductive elastic layer 16 to a predetermined range is not particularly limited, but for example, carbon-based magnetic powder such as carbon black or graphite; tin, iron, Metal powders such as copper and metal fibers and mixtures thereof with resins; metal oxides such as zinc oxide, tin oxide, titanium oxide; metal sulfides such as copper sulfide and zinc sulfide; so-called strontium, barium, rare earths, etc. Hard ferrite; ferrite such as magnetite, copper, zinc, nickel and manganese, or those whose surface is subjected to conductive treatment as necessary; copper, iron, manganese, nickel, zinc, cobalt, barium, aluminum, tin,
A solid solution of a metal oxide selected from oxides, hydroxides, carbonates or metal compounds containing different metal elements such as lithium, magnesium, silicon and phosphorus, and obtained by firing at high temperature (so-called composite metal oxide Thing); etc. are mentioned.
Further, an ionic conductive agent such as a quaternary ammonium salt or a metal substitution product of a quaternary ammonium salt may be used. These resistance adjusting agents may be used alone or in combination of two or more kinds. In addition, the additives used for adjusting the electric resistance within a predetermined range may be used alone or in combination of several kinds.

In the present invention, the semiconductive elastic layer 16 has an electric resistance of 1 × 10 ⁴ Ω to 1 × when 100 V is applied.
It is preferably in the range of 10 ¹⁰ Ω. If the electric resistance of the semiconductive elastic layer 16 at the time of applying 100 V is less than 1 × 10 ⁴ Ω, pinholes or low-resistance foreign matters are attached to the image carrier when the electrophotographic roller 10 obtained is used as a charging member. When there is such a leak, a leak may occur and an image defect may be caused. On the other hand, if the electric resistance of the semiconductive elastic layer 16 when 100 V is applied exceeds 1 × 10 ¹⁰ Ω, a voltage drop occurs in the semiconductive elastic layer 16, making it difficult to obtain the required amount of current, The function as a charging member or a transfer member may not be achieved.

The method for measuring the electric resistance of the semiconductive elastic layer 16 when 100 V is applied is as described in 1 of the conductive elastic layer 14 described above.
The method is the same as the method of measuring the electric resistance when 0 V is applied, except that the applied voltage is different. However, since the semiconductive elastic layer 16 is formed on the outer periphery of the conductive elastic layer 14, it is not possible to measure the electric resistance in the actual process of manufacturing the electrophotographic roll. By forming the same conductive elastic layer 14 on the shaft,
taking measurement. At this time, when the semiconductive elastic layer 16 is made of a seamless tube, the actual semiconductive elastic layer 16 is obtained by externally inserting the seamless tube in the process of manufacture into a metal shaft having an appropriate diameter. Can be measured directly.

In the present invention, the semiconductive elastic layer 16 preferably has a thickness of 100 μm or more.
It is more preferable that the thickness is 0 μm or more. Even if the electric resistance of the semiconductive elastic layer 16 is adjusted to the above range, if the thickness is less than 100 μm, leakage may still occur and an image defect may be caused. The upper limit of the thickness is not particularly limited, but if it is extremely thick, the hardness of the electrophotographic roller 10 as a whole becomes high, and when this is used as a charging member, it causes toner filming on the surface of the image carrier. Since it may cause a cause, an appropriate thickness is required, and a thickness of about 2 mm is considered to be the upper limit.

In the present invention, the hardness of the semiconductive elastic layer 16 is preferably 70 ° or less, and more preferably 60 ° or less in terms of micro rubber hardness. Here, the “micro rubber hardness” means that a sample (semi-conductive elastic layer 16) to be measured is cut out to prepare a sample, and the hardness in the thickness direction of the sample is measured by a micro rubber hardness meter (Kobunshi Keiki Co., Ltd. Made, MD-1)
Refers to the value measured using.

In particular, Japanese Unexamined Patent Publication (Kokai) No. 11-125956 describes a charging member in which a nylon tube having a thickness of 100 μm is coated on the outer circumference of a foam, and the hardness of the entire charging member is 90 in ASKER-F. Although there is a statement that it is less than or equal to °, no matter how soft the hardness of the entire charging member is, if the layer itself forming the surface of the charging member is a hard material such as nylon, the surface of the image carrier can be easily Toner filming occurs. In other words, in the charging member that comes into contact with the image carrier, the hardness of the portion forming the surface layer (outer layer) of the charging member must be kept below a certain hardness, rather than the hardness of the entire charging member. Therefore, it is desirable to satisfy the above-mentioned regulation of the micro rubber hardness.

In the present invention, the semiconductive elastic layer 16 is
It is desirable to use a seamless tube composed of one or more layers and one or more materials. With such a configuration, the semiconductive elastic layer having the desired electric resistance and hardness can be simply and continuously molded,
The cost merit is very large.

In order to strengthen the bond between the conductive elastic layer 14 and the semiconductive elastic layer 16, the conductive elastic layer 14 is formed.
It is desirable that a conductive adhesive layer (not shown) is formed between and the semiconductive elastic layer 16. The method for forming the conductive adhesive layer, the conductive adhesive to be used, the preferable mode of the conductive adhesive layer, and the like are the same as those described in the section <Conductive elastic layer>.

The surface of the formed conductive elastic layer 14 (the surface of the surface coating when further surface coating is applied) has a ten-point average roughness (Rz) of 1
It is preferably in the range of 10 μm. Achieving a surface smoothness of less than 1 μm requires a very advanced coating technique, and a surface roughness of more than 10 μm results in an excessively large surface roughness. They are not preferable because they cannot be charged.

<Metal Shaft> Finally, the metal shaft which is the axis of the electrophotographic roller of the present invention will be described. The metal shaft 12 is formed in a cylindrical shape from a metal material such as iron, stainless steel, and aluminum.
The diameter is not particularly limited, but is preferably in the range of 1 to 8 mm from the viewpoint of downsizing of the device. Further, the length may be appropriately selected depending on the usage mode, but in general electrophotographic applications, it is preferably longer than the lengthwise direction of A4 size.

The electrophotographic roller of the present invention described above is preferably used as a charging roller in an electrophotographic apparatus, but by adjusting the electric resistance value to an appropriate value,
It can also be suitably used as a conductive roller or a semiconductive roller such as a transfer roller, a primary transfer roller and a secondary transfer roller in an intermediate transfer system.

B: Image Forming Apparatus The image forming apparatus of the present invention is used as a member of either a conductive or semi-conductive roller in an electrophotographic apparatus for forming a toner image on a recording material by an electrophotographic method. This is an application of an electrophotographic roller. Hereinafter, specific modes will be described.

<Aspect A> At least an image bearing member and a charging member in contact with the image bearing member are provided. Prior to forming an electrostatic latent image, a voltage is applied to the charging member while the charging member and the image are charged. An image forming apparatus including a structure in which a surface of the image carrier is charged by rotating the carrier and the carrier, respectively, wherein the charging member is the electrophotographic roller of the present invention.

According to this aspect, as described above, since the conductive elastic layer having a three-dimensional network structure has an extremely low hardness, the electrophotographic roller is coated even after being coated with the semiconductive elastic layer. Can be freely deformed, and the nip width with the image carrier can always be kept uniform. Further, even when the outer diameter of the electrophotographic roller is made smaller than that of the conventional one, it is possible to secure a uniform nip width without floating the central portion. Furthermore, during charging (when AC / DC superimposed voltage is applied)
Vibration of the image carrier can be absorbed, the charging noise can be suppressed, and the wear on the surface of the image carrier can be reduced because the stress on the image carrier is small.
Further, since the electrophotographic roller of the present invention is a charging member having a small variation in resistance, it also has excellent charging stability.

In this embodiment, the charging member and the image carrier may have a peripheral speed difference.
In the case of having such a peripheral speed difference, it is 1.1 with respect to the image carrier.
The charging member composed of the electrophotographic roller of the present invention can be swiftly rotated to about three times to three times, and by providing a peripheral speed difference, the resistance unevenness of the electrophotographic roller of the present invention can be further eliminated. it can.

In the charging member of the type in which only the DC voltage is applied, it is desired to eliminate the variation in the electric resistance of the entire electrophotographic roller in a higher dimension. Therefore, in this embodiment, the voltage applied to the charging member is used. Is particularly effective when it is a DC voltage.

<Aspect B> At least, an image carrier on which a toner image is formed on a surface by a predetermined means, and a transfer member that abuts on the image carrier to form a nip portion, and the transfer material is inserted into the nip portion. In the image forming apparatus, the toner image on the surface of the image carrier is transferred to the transfer material to form an image, and the transfer member is the electrophotographic roller of the present invention.

According to this aspect, it is easy to ensure the nip uniformity at the transfer portion. In particular, since a transfer nip can be uniformly ensured regardless of the type of transfer material (thin paper to thick paper), an extremely stable transfer process is possible.

<Aspect C> At least an image carrier on which a toner image is formed by a predetermined means, and a primary transfer means for transferring the toner image on the surface of the image carrier to an intermediate transfer body,
An image forming apparatus comprising: a secondary transfer unit that transfers the toner image on the surface of the intermediate transfer member to a transfer material, wherein the primary transfer unit and / or the secondary transfer unit is for electrophotography according to the present invention. The aspect which is a roller.

According to this aspect, it is easy to ensure the nip uniformity at the transfer portion. In particular, when the electrophotographic roller of the present invention is applied to the secondary transfer means, the transfer nip can be uniformly ensured regardless of the type of transfer material (thin paper to thick paper), so that an extremely stable transfer process is possible.

The image forming apparatus of the present invention has been described above with reference to three modes. However, for the constitution other than the charging member or the transfer member adopting the electrophotographic roller of the present invention, an image of an electrophotographic system has been conventionally used. Known configurations can be applied as the respective configurations of the forming apparatus without any problem.

That is, for example, as the image bearing member, a ceramic type photosensitive member known as a photosensitive member in the related art, an organic photosensitive member (OPC) in which an organic photosensitive layer is formed, or the like can be applied without any problem. The same applies to the intermediate transfer member, the primary transfer unit, the secondary transfer unit, and the charging member or transfer member to which the electrophotographic roll of the present invention is not adopted.

Further, the image forming apparatus of the present invention has a constitution other than the constitution described above, for example, a latent image forming means, a developing means, a cleaning means, a discharging means, a paper feeding means, a conveying means, an image control means and the like. Conventionally known materials are appropriately adopted as necessary. Of course, these configurations are not limited in the present invention.

[0080]

[Example] (Example 1) Polyether and isocyanate were mixed and sufficiently bubbled using a stirrer. The urethane resin thus obtained was heat-cured to prepare a urethane material having a three-dimensional network structure. When the structure of the obtained urethane material having a three-dimensional network structure was observed with a microscope, the shortest distance between skeletons was 300 μm or more (average 500 μm), and the thickness of the skeleton was 800 μm or less (average 250 μm). .

The obtained urethane material having a three-dimensional mesh structure was cut out as a prism having a side of 10 mm and a length of 320 mm, and a hole penetrating in the longitudinal direction with 5 mmφ was provided at the center thereof. Next, a 5 mmφ stainless steel metal shaft coated with 5 μm of a polyester-based conductive adhesive (electrical resistance at 100 V is 2 × 10 ¹ Ω, viscosity is 50 cP) is prepared on the outer periphery, and the metal shaft is connected to the above 3 The two were integrated by inserting them into the holes provided in the urethane material having a three-dimensional mesh structure. After that, the shaft was rotated at a high speed to polish the outer peripheral urethane material having a three-dimensional network structure to produce a roll having an elastic layer made of urethane having a three-dimensional network structure with an outer diameter of 9 mmφ.

Further, the obtained roll is dipped in the above polyester-based conductive adhesive, and the elastic layer made of urethane having a three-dimensional network structure is subjected to a conductive treatment to form a conductive elastic layer. Obtained. The conductive roll obtained,
As described above, a DC voltage of 10 V was applied as shown in FIG. 2 and the electric resistance between the metal shaft 12 and the flat plate 22 was measured. As a result, the electric resistance was 5 × 10 ³ Ω.

Separately from this, epichlorohydrin rubber 1
3 parts by mass of an ion conductive agent PEL-100 (manufactured by Japan Carlit Co., Ltd.) was added to 00 parts by mass and sufficiently kneaded, and then, using an extruder, an outer diameter of 10 mmφ, a wall thickness of 500 μm, and a semiconductivity of 320 mm. A seamless tube made of epichlorohydrin rubber to be an elastic layer was prepared.

An outer diameter of 9 was placed in the obtained seamless tube.
A stainless steel shaft of mmφ is inserted, and the same process as in the case of the conductive roll having the conductive elastic layer is performed.
Applying a DC voltage of 0V, the metal shaft 12 and the flat plate 22
The electrical resistance between and was measured. As a result, the electric resistance of the epichlorohydrin rubber seamless tube, which is the semiconductive elastic layer, was 6 × 10 ⁵ Ω.

A part of the obtained seamless tube made of epichlorohydrin rubber was dissected and the hardness in the thickness direction was measured by using a micro rubber hardness meter (MD-1) manufactured by Kobunshi Keiki Co., Ltd. As a result, the micro rubber hardness was 55. It was °. Furthermore, the ten-point average roughness (Rz) at 20 locations in the obtained epichlorohydrin rubber seamless tube
Was measured, and the average value was 3 μm.

The epichlorohydrin rubber seamless tube thus obtained was coated on the outer periphery of the conductive roll on which the conductive elastic layer had been formed previously with the polyester conductive adhesive of 5 μm. Then, the roller for electrophotography of Example 1 was obtained by extrapolation.

The obtained electrophotographic roller was attached as the charging member 32 of the image forming apparatus shown in FIG. 3, and the high temperature / high humidity environment (temperature 28 ° C., humidity 85% Rh), low temperature / low humidity environment (temperature 10 ° C., Humidity 15% Rh), standard environment (temperature 22
It was subjected to an image output test of 50,000 sheets under each environment of ° C and humidity 55% Rh).

In the image forming apparatus shown in FIG. 3, the photoconductor 34 as an image carrier, the charging member 32 for charging the surface of the photoconductor 34, and the photoconductor 34 by exposing the photoconductor 34 imagewise. An exposing unit 36 for forming an electrostatic latent image on the surface, a developing device 38 for developing the electrostatic latent image with toner to form a toner image, and a toner image formed on the surface of the photoconductor 34 on a transfer material 42. And a transfer means 40 for transferring. Although not shown, by inserting the transfer material 42 on which the unfixed toner image is formed between the pair of rolls,
A fixing device for fixing with heat and pressure is also provided separately.
More specifically, the apparatus uses Able 3321 manufactured by Fuji Xerox Co., Ltd. and is modified so that the charging member 32 is replaced with that of the present embodiment. The applied voltage here was a DC voltage of -1300V.

As a result, in any of the high temperature / high humidity environment, the low temperature / low humidity environment, and the standard environment, there is no problem in the initial and 50,000th images, and the photoconductor 34
No abnormality such as filming of toner was observed on the surface,
The scraping amount of the charge transport layer of the photoconductor 34 was 3 μm at maximum in a low temperature / low humidity environment, which was an extremely small value. Also,
No abnormality such as scratches or pinholes was observed on the surface of the electrophotographic roller as the charging member 32. further,
No difference was observed in the electric resistance of the electrophotographic roller at the initial stage and after the 50,000-sheet durability test.

(Example 2) Styrene / ethylene butylene / olefin crystal block copolymer (SEBC: DY)
50 parts by mass of NARON 4600P / manufactured by Japan Synthetic Rubber Co., Ltd. and hydrogenated styrene-butylene copolymer (HSB
R: DYNARON 2324P / manufactured by Japan Synthetic Rubber Co., Ltd.)
In 50 parts by mass, 10 parts by mass of conductive carbon black (Ketjen Black EC: Ketjen Black Inc), 15 parts by mass of conductive titanium oxide (ET-500W: manufactured by Ishihara Sangyo Co., Ltd.), and ion conductive agent PEL-100. After dry blending 3 parts by mass (manufactured by Japan Carlit Co.), 2 parts by mass of filler (calcium carbonate), 1 part by mass of dispersion aid (zinc stearate) and 1 part by mass of surface modifier, The mixture was thoroughly kneaded at 200 ° C. for 10 minutes using a pressure kneader.

The kneaded product taken out from the pressure kneader was crushed and then pelletized using a twin-screw extruder. From the obtained pellets, using a single-screw extruder equipped with a crosshead, an outer diameter of 10 mmφ, a wall thickness of 500 μm, and a length of 3
A 20 mm styrene elastomer seamless tube was prepared.

A stainless metal shaft having an outer diameter of 9 mmφ was inserted into the obtained styrene elastomer seamless tube, and a DC voltage of 100 V was applied in the same manner as in Example 1 to form the metal shaft 12 and the flat plate 22. The electrical resistance between them was measured. As a result, the electrical resistance of the styrene elastomer seamless tube was 8 × 10 ⁵ Ω.

Further, as a result of cutting a part of the seamless tube made of styrene elastomer and measuring the hardness in the thickness direction using a micro rubber hardness meter (MD-1) manufactured by Kobunshi Keiki Co., Ltd., the micro rubber hardness was 60 °. It was further,
When the ten-point average roughness (Rz) of 20 points in the obtained styrene elastomer seamless tube was measured, the average value was 2 μm.

The styrene elastomer seamless tube thus obtained was applied to the outer periphery of the conductive roll having the conductive elastic layer formed in Example 1 on the outer periphery of the polyester conductive adhesive in the same manner as in Example 1. Was applied and then extrapolated to obtain an electrophotographic roller of Example 2.

The obtained electrophotographic roller was attached as the charging member 32 of the image forming apparatus shown in FIG. 3 in the same manner as in Example 1 and subjected to an image output test of 50,000 sheets in each environment as in Example 1. The applied voltage here is -1300V.
DC voltage was used.

As a result, in any of the high temperature / high humidity environment, the low temperature / low humidity environment, and the standard environment, there is no problem in the initial and 50,000th images, and the photoconductor 34
No abnormality such as filming of toner was observed on the surface,
The amount of abrasion of the charge transport layer of the photoconductor 34 was 4 μm at maximum in a low temperature / low humidity environment, which was an extremely small value. Also,
No abnormality such as scratches or pinholes was observed on the surface of the electrophotographic roller as the charging member 32. further,
No difference was observed in the electric resistance of the electrophotographic roller at the initial stage and after the 50,000-sheet durability test.

(Comparative Example 1) 100 parts by weight of polystyrene was mixed with conductive carbon black (Ketjen Black E).
C: Ketjen Black Inc) (20 parts by mass) and expanded beads (20 parts by mass) were dispersed, and injection molding was performed to produce a foam having an average cell diameter of 300 μm. The obtained foam was cut out as a prism having a side of 10 mm and a length of 320 mm, and a hole penetrating in the longitudinal direction with 5 mmφ was provided at the center thereof.

Next, a 5 mmφ stainless steel metal shaft coated with 5 μm of polyester conductive adhesive (electrical resistance when 100 V is applied, electric resistance is 2 × 10 ¹ Ω, viscosity is 50 cP) is prepared on the outer periphery. Then, it was inserted into a hole provided in the foam to integrate them. Then, this shaft was rotated at a high speed to polish the outer peripheral foamed body, thereby producing a conductive roll provided with a foamed layer having an outer diameter of 9 mmφ. The conductive roll obtained was used in Example 1
Similarly to the above, a DC voltage of 10 V was applied and the electrical resistance between the metal shaft 12 and the flat plate 22 was measured. As a result, the electric resistance of the foam layer was 1 × 10 ³ Ω.

Then, the epichlorohydrin rubber seamless tube prepared in Example 1 was applied to the outer periphery of the foam layer by 5 μm of the polyester conductive adhesive.
After applying m, it was extrapolated to obtain a roller for electrophotography of Comparative Example 1. The obtained electrophotographic roller was attached as the charging member 32 of the image forming apparatus shown in FIG. 3 as in Example 1, and subjected to an image output test of 50,000 sheets in each environment as in Example 1. The applied voltage here was a DC voltage of -1300V.

As a result, even in the standard environment, the charging member (electrophotographic roller) 32 and the photoconductor 3 are started from the initial stage.
4, a periodic gap was formed in the center of the nip portion with respect to No. 4, and a banana-shaped fog occurred on the image formed on the transfer material 42 in the cycle of the charging member 32.

This indicates that the conductive foam layer used here cannot be freely deformed like the conductive elastic layer having a three-dimensional network structure according to the present invention, and a normal foam is uniform. The nip cannot be secured. Therefore, subsequent tests could not be performed.

(Comparative Example 2) Nylon 12 resin (PA1
2) 100 parts by mass, 12 parts by mass of conductive carbon black (Ketjen Black EC: Ketjen Black Inc), 15 parts by mass of conductive titanium oxide (ET-500W: Ishihara Sangyo), and ionic conductive agent PEL-100. After dry blending 2 parts by mass (manufactured by Japan Carlit Co.), 2 parts by mass of filler (calcium carbonate), 1 part by mass of dispersion aid (stearic acid), and 0.5 parts by mass of surface modifier. Using a pressure kneader, the mixture was sufficiently kneaded at 250 ° C. for 10 minutes.

The kneaded product taken out from the pressure kneader was crushed and then pelletized using a twin-screw extruder. From the obtained pellets, using a single-screw extruder equipped with a crosshead, an outer diameter of 9.2 mmφ, a wall thickness of 100 μm, and a length of 3
A 20 mm nylon 12 seamless tube was prepared.

A stainless steel metal shaft having an outer diameter of 9 mmφ was inserted into the obtained nylon 12 seamless tube, and a DC voltage of 100 V was applied in the same manner as in Example 1 to form the metal shaft 12 and the flat plate 22. The electrical resistance between them was measured. As a result, the electric resistance of the nylon 12 seamless tube was 1 × 10 ⁵ Ω.

Further, as a result of cutting a part of the nylon 12 seamless tube and measuring the hardness in the thickness direction using a micro rubber hardness meter (MD-1) manufactured by Kobunshi Keiki Co., Ltd.,
The micro rubber hardness exceeded the measurable range (upper limit of 100 °). Furthermore, when the ten-point average roughness (Rz) of 20 points in the obtained nylon 12 seamless tube was measured, the average value was 1.5 μm.

The nylon 12 seamless tube thus obtained was applied to the outer periphery of the conductive roll having the conductive elastic layer formed in Example 1 on the outer periphery of the polyester type conductive adhesive in the same manner as in Example 1. Was applied and then extrapolated to obtain a roller for electrophotography of Comparative Example 2.

The obtained electrophotographic roller was attached as the charging member 32 of the image forming apparatus shown in FIG. 3 as in Example 1 and subjected to an image output test of 50,000 sheets in each environment as in Example 1. The applied voltage here is -1300V.
DC voltage was used.

As a result, toner filming occurs on the surface of the photoconductor 34 at the stage of several hundreds of sheets under any environment of high temperature / high humidity environment, low temperature / low humidity environment, and standard environment. However, an image defect due to it was also confirmed. Therefore, the image output test could not be performed up to 50,000 sheets, and had to be finished at the stage of 1,000 sheets.

[0109]

As described above, according to the present invention,
Suppresses the generation of electrification noise and reduces abrasion of the image carrier,
Further, it is possible to provide an electrophotographic roller excellent in charging stability and capable of ensuring a sufficient nip width even with a small diameter, and an image forming apparatus using the same at low cost.

Further, according to the electrophotographic roller and the image forming apparatus using the same of the present invention, the following effects can be expected in a more preferable mode. 1) By optimizing the combination of the electric resistances of the conductive elastic layer and the semiconductive elastic layer, it is possible to provide an electrophotographic roller in which the resistance variation is extremely suppressed.

2) The charge-up can be eliminated by optimizing the combination of the electric resistances of the conductive elastic layer and the semi-conductive elastic layer. Therefore, even when used as a charging member for applying only a DC voltage, It is possible to provide an electrophotographic roller that maintains stable electric resistance for a long period of time.

3) Due to the effects of 1) and 2) above,
It is possible to provide a charging member in which generation of charging noise is suppressed to a higher level and abrasion of the image carrier can be extremely reduced.

4) By optimizing the combination of hardnesses of the conductive elastic layer and the semiconductive elastic layer, it is possible to provide an electrophotographic roller which eliminates the occurrence of toner filming.

5) By optimizing the combination of hardness of the conductive elastic layer and the semiconductive elastic layer, it is possible to provide an electrophotographic roller having a diameter significantly smaller than that of the conventional one. It is possible to provide an electrophotographic roller that can achieve cost reduction and device miniaturization.

6) As described above, the electrophotographic roller of the present invention has been mainly applied to the charging member. However, the electric resistance of the semiconductive elastic layer may be adjusted to a desired value. The transfer roller can be easily diverted, and in this case, the same effects as in 1) and 2) above can be sufficiently expected. The transfer roller mentioned here includes a primary transfer roller and a secondary transfer roller when an intermediate transfer member is used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an electrophotographic roller of the present invention, FIG. 1 (A) is a longitudinal sectional view, and FIG.
FIG. 1B is a sectional view taken along the line AA in FIG.

FIG. 2 is an explanatory diagram for explaining a method for measuring an electric resistance of a conductive elastic layer or a semiconductive elastic layer.

FIG. 3 is a schematic configuration diagram illustrating a schematic configuration of an image forming apparatus used in an example.

[Explanation of symbols]

10 Electrophotographic roller 12 metal shaft 14 Conductive elastic layer 16 Semi-conductive elastic layer 20 Conductive roll 22 flat plate 24 power supply 26 ammeter 32 Charging member (Electrophotographic roller) 34 photoconductor (image carrier) 36 Exposure Means 38 Developing device 40 transfer means 42 Transfer material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manabu Furuki             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Yoshihiro Maekawa             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Kazuo Sueyoshi             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Hiroyuki Miura             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Masato Ono             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Taku Takayama             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Naoki Onishi             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Hitoshi Kazono             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. F-term (reference) 2H071 BA43 DA06 DA09                 2H200 FA01 FA02 FA10 FA16 FA18                       GA23 GA33 GA44 GB22 GB23                       HA03 HA29 HB12 HB22 HB43                       HB45 HB46 HB47 HB48 JA02                       JA23 JA25 JA26 JA27 JA28                       JA29 JC02 JC13 JC15 JC16                       JC17 JC18 JC19 LC04 LC08                       MA03 MA04 MA05 MA11 MA20                       MB01 MB02 MB06 MC01 MC02                       NA02 NA06 PA11                 3J103 AA02 AA13 AA32 AA51 AA85                       BA41 EA02 EA07 FA04 FA18                       GA02 GA57 GA58 GA60 HA03                       HA12 HA20 HA54

Claims (15)

[Claims] 1. A conductive elastic layer having a three-dimensional mesh structure is formed on the outer periphery of a metal shaft, and a semiconductive elastic layer is further formed on the outer periphery of the conductive elastic layer. Roller for electrophotography. 2. The electric resistance of the conductive elastic layer when applying 10 V is 9 × 10 ⁴ Ω or less, and the electric resistance of the semi-conductive elastic layer when applying 100 V is 1 × 10 ⁴ Ω.
The electrophotographic roller according to claim 1, wherein the electrophotographic roller has a resistance of about 1 × 10 ¹⁰ Ω. 3. The shortest distance between skeletons in the three-dimensional network structure of the conductive elastic layer is 200 μm or more, and the skeleton has a thickness of 1000 μm or less. Roller for electrophotography. 4. The semiconductive elastic layer has a thickness of 100 μm.
The electrophotographic roller according to any one of claims 1 to 3, wherein the semi-conductive elastic layer has a micro rubber hardness of 70 ° or less. 5. The semiconductive elastic layer has one or more layers and one or more layers.
The electrophotographic roller according to any one of claims 1 to 4, which is composed of a seamless tube made of one or more kinds of materials. 6. A conductive adhesive layer is formed on the outer circumference of a metal shaft, the conductive elastic layer is formed on the conductive adhesive layer, and a conductive adhesive is applied on the conductive elastic layer. The electrophotographic roller according to claim 1, wherein a semiconductive elastic layer is formed. 7. The conductive elastic layer and the semiconductive elastic layer are each formed as a seamless tube, and are sequentially laminated on the outer circumference of the metal shaft using a conductive adhesive. The roller for electrophotography according to any one of claims 1 to 5. 8. The conductive elastic layer and the semiconductive elastic layer are simultaneously formed as a seamless tube and are bonded to the outer circumference of the metal shaft via a conductive adhesive. The roller for electrophotography according to any one of to 5. 9. A charging member which contacts the surface of the image carrier and charges the surface of the image carrier.
8. The roller for electrophotography according to any one of 8. 10. The electrophotographic roller according to claim 1, which is a transfer member for transferring a toner image formed on the surface of the image carrier to a transfer material. 11. An image carrier and at least a charging member in contact with the image carrier, which are provided before forming an electrostatic latent image.
An image forming apparatus including a structure for charging the surface of the image bearing member by rotating the charging member and the image bearing member respectively while applying a voltage to the charging member, wherein the charging member is An image forming apparatus comprising the electrophotographic roller according to claim 9. 12. The image forming apparatus according to claim 10, wherein the charging member and the image carrier have a peripheral speed difference. 13. The image forming apparatus according to claim 10, wherein the voltage applied to the charging member is a DC voltage. 14. An image carrier having at least a toner image formed on a surface thereof by a predetermined means, and a transfer member that abuts on the image carrier to form a nip portion, and the transfer material is inserted into the nip portion. 11. An image forming apparatus including a structure for forming an image by transferring the toner image on the surface of the image carrier to the transfer material, wherein the transfer member is the electrophotographic roller according to claim 10. A characteristic image forming apparatus. 15. An image carrier on which a toner image is formed on the surface by at least a predetermined means, a primary transfer means for transferring the toner image on the surface of the image carrier to an intermediate transfer body, and the surface of the intermediate transfer body. 9. An image forming apparatus, comprising: a secondary transfer unit that transfers the toner image according to claim 1 to a transfer material, wherein the primary transfer unit and / or the secondary transfer unit. Image forming apparatus, which is a roller for electrophotography.