JP2002091132A - Electrostatic charging member using simultaneously molded multilayer tube as well as process cartridge and electrophotographic device having this electrostatic charging member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charging member which does not give rise to the nonuniformity of the local adhesion force of a simultaneously molded multiplayer tube and electrostatic charging defect caused by tight adhesion defect among the respective layers as well as a process cartridge and electrophotographic device having this electrostatic charging member. SOLUTION: The electrostatic charging member is formed by covering the outer periphery of a foamed elastic body layer 2 on the outer periphery of an arbor 1 with a double functional layer tube obtained by simultaneous molding of the arbor 1, the foamed elastic body layer 2 and plural layers of the functional films 3. The total (Δγrsd+Δγrsp+Δγrsh) of the difference (Δγrsd) in the dispersion components of the surface free energy between the layers in contact with each other of the double functional layer tube and the difference (Δγrsp) of their polar components and the difference (Δγrsh) of the hydrogen bond components is <=20 mN/m. The process cartridge and electrophotographic device have this electrostatic charging member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member which is arranged in contact with a member to be charged and charges the member by applying a voltage, a process cartridge having the charging member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In recent years, as a charging means used in an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, a charging means of a contact charging system has been adopted. Contact charging is to charge a charged body to a predetermined polarity and potential by applying a voltage to a charging member arranged in contact with the charged body, and it is possible to lower the voltage of a power supply, such as ozone. There are advantages that the generation of corona products can be reduced, the structure is simple and the cost can be reduced.

[0003] The voltage applied to the charging member has a peak not less than twice the charging start voltage of the member to be charged when a DC voltage is applied to the contact charging member, in addition to the method of applying only DC (DC application method). There is a method of forming an oscillating electric field having an inter-voltage (an electric field whose voltage value periodically changes with time) between the contact charging member and the charged body to charge the surface of the charged body (AC application method). This enables more uniform charging.

Further, the contact charging device is based on a roller type charging device using a charging member as a roller-shaped member (charging roller) (Japanese Patent Laid-Open Publication No. Sho 63-163).
7380 and JP-A-56-91253, etc., and a blade-type charger using a blade-shaped member (charging blade) (JP-A-64-24264 and JP-A-5-224).
No. 6-194349) and a brush-type charger as a brush-like member (charging brush) (JP-A-64-24264).
No., etc.).

[0005] The charging roller is rotatably supported by a bearing and pressed against the member to be charged at a predetermined pressure, and is rotated by the movement of the member to be charged. The charging roller is generally a multilayer structure having a core provided at the center as a base, a conductive elastic layer provided in a roller shape on the outer periphery of the core, and a surface layer provided on the outer periphery thereof. is there. Among the above layers, the core metal (metal layer) is a rigid body for maintaining the shape of the roller, and has a role as a power supply electrode.

The elastic layer is usually 1 × 10 ⁴ to 1
Since it is required to have a volume specific resistance of × 10 ⁹ Ω · cm and a function of ensuring uniform contact with the member to be charged by being elastically deformed, usually, a rubber hardness provided with conductivity (JIS) -A) A vulcanized rubber having a flexibility of 70 degrees or less is used. Conventional charging rollers include a foam type using a rubber foam (or sponge-like rubber) as an elastic layer and a solid type using no rubber foam.

The surface layer improves the charging uniformity of the member to be charged, prevents the occurrence of leaks due to pinholes and the like on the surface of the member to be charged, and also prevents the adhesion of toner particles, paper powder, and the like. It has a function, and also a function of preventing bleeding of a softening agent such as an oil or a plasticizer used for lowering the hardness of the elastic layer. The volume resistivity of the surface layer is usually 1 × 10 ⁵ to 1 × 10 ¹³ Ω · cm. Conventionally, it has been formed by applying a conductive paint or coating a seamless tube.

[0008] As a method of manufacturing a tube-coated roller,
There are a method using a heat-shrinkable tube and a method using a non-heat-shrinkable tube. When using a heat-shrinkable tube, insert a metal core or an elastic roller with an elastic body formed on the metal core into a heat-shrinkable tube with a primer applied on the inner surface, and heat the entire tube to shrink the tube to make the roller Cover the outer circumference. When a non-heat-shrinkable tube is used, the non-heat-shrinkable tube is placed on the inner wall of the cylindrical mold while being pulled in the longitudinal direction, and the pressure between the tube and the inner wall of the cylindrical mold is reduced to form the inner wall of the tube. Then, after inserting an elastic roller having an elastic body formed on the outer periphery of the cored bar, the tube was coated on the outer periphery of the roller by heat fusion.

However, when using a heat-shrinkable tube,
Although the manufacturing process is simple, it is difficult to manufacture the heat-shrinkable tube, and uneven wall thickness is inevitable and expensive. Also,
Adjustment of shrinkage is also difficult, and there are problems such as wrinkles. When a non-heat-shrinkable tube is used, a non-heat-shrinkable tube having a uniform thickness without uneven thickness can be obtained at a low cost, but the production of a roller having a multilayer surface layer requires skill in the process. However, problems such as generation of wrinkles and twisting of the tube were likely to occur.

On the other hand, when the above-mentioned multilayer portion is formed of a tube, problems such as pinholes can be avoided, and control of the film thickness is relatively easy. However, in the case of a conventional tube, it is very difficult to form a tube having a thin film thickness of 30 μm or less. Therefore, a multilayer resistive layer is prepared by preparing a plurality of single-layer tubes and externally fitting them one by one.
When they are formed in an overlapping manner, the thickness of the entire resistance layer is increased, so that it is difficult to obtain a roller having a desired resistance value.

To cope with this, there is a method of simultaneously forming the above-mentioned multilayer tube (Japanese Patent Laid-Open No. 11-25952).
Usually, for recovery immediately after molding, because the tube is quenched with cooling water etc., due to the difference in elastic modulus of each layer and the difference in residual strain, depending on the combination of tube materials, the multilayer tube that was in close contact at the time of molding may be There is a defect that the adhesion becomes insufficient, and peels off at the time of coating or use, and the unevenness of the interface resistance caused by the unevenness of the adhesion directly appears as an image defect.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a charging member which does not cause uneven charging due to local uneven adhesion of a simultaneously formed multilayer tube or poor charging caused by poor adhesion between layers. It is in.

Another object of the present invention is to provide a process cartridge having the charging member and an electrophotographic apparatus.

[0014]

According to the present invention, there is provided a functional multi-layer tube obtained by simultaneously molding a core, a foamed elastic layer on the outer periphery of the core, and a plurality of functional films. In the charging member coated on the outer periphery of the foamed elastic material layer, the difference between the dispersion component (Δγsd) of the surface free energy and the difference (Δγs
p) and the sum of the difference (Δγsh) between the hydrogen bond components (Δγsd)
+ Δγsp + Δγsh) is 20 mN / m or less.

Further, according to the present invention, an electrophotographic photosensitive member and a charging member, or one or both of an electrophotographic photosensitive member, a charging member, a developing unit, and a cleaning unit are integrally supported and attached to and detached from an electrophotographic apparatus main body. In the flexible process cartridge, the charging member is a charging member that is disposed in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member when a voltage is applied, and the charging member is the charging member. A featured process cartridge is provided.

Further, according to the present invention, an electrophotographic photoreceptor,
In an electrophotographic apparatus having a charging member, an exposure unit, a developing unit, and a transfer unit, the charging member is disposed in contact with the electrophotographic photosensitive member, and charges the electrophotographic photosensitive member by applying a voltage. And an electrophotographic apparatus characterized by being the charging member described above.

[0017]

Embodiments of the present invention will be described below in more detail.

FIG. 1 shows an example of a charging member (hereinafter, also referred to as a charging roller) 1 'of the present invention, which is used as a charger of an electrophotographic apparatus. This charging roller is
A foamed elastic layer 2 made of a conductive elastic material is provided on the outer periphery of a cored bar 1 made of a good conductive material such as stainless steel, plated iron, brass, and conductive plastic. Is coated with a tube-shaped functional multilayer film 3 on its outer periphery. In the case of FIG. 1, the functional multilayer film includes an inner layer 3 (i) and an outer layer 3 (o).

As the core metal (metal layer) in the present invention,
For example, a good conductor such as aluminum, copper, iron, or an alloy containing these is preferably used. The metal core used in the present invention may be a metal tube having a thickness of about 0.1 to 1.5 mm or a rod.

Here, as the conductive elastic material constituting the foamed elastic layer 2, a foamed conductive rubber composition containing a conductive material or a conductive polyurethane foam can be used.

In this case, the rubber component constituting the foamed conductive rubber composition is not particularly limited.
Ethylene-propylene-diene rubber (EPDM), chloroprene, chlorosulfonated polyethylene blended with conductive material, foam, copolymer rubber of epichlorohydrin and ethylene oxide or copolymer rubber of epichlorohydrin and ethylene oxide A foam containing a conductive material can be suitably used.

Examples of the conductive material to be added to these rubber compositions include conductive powders such as carbon black, graphite, metal and various conductive metal oxides (such as tin oxide and titanium oxide), carbon fiber and metal oxide. Various conductive fibers such as short fibers of the product can be used. The compounding amount is preferably 3 to 100 parts by mass with respect to 100 parts by mass of all rubber components.
Parts by mass, particularly preferably 5 to 50 parts by mass, whereby the volume resistance of the foamed elastic layer 2 is 1 × 10 to 1 × 10 ⁹
It is preferable to adjust to about Ω · cm. The foamed elastic layer 2 can be formed by a known vulcanization molding method. The thickness of the foamed elastic layer 2 is appropriately set according to the use of the charging roller, but is usually preferably 1 to 20 mm.

In the present invention, a functional multilayer film 3 is coated on the foamed elastic layer 2 in the form of a tube. In this case, the thermoplastic resin constituting the functional multilayer film 3 may be, as described in the claims, a difference (Δγsd) in the dispersion component of the surface free energy of the layers in contact with each other in the functional multilayer tube. ) And the difference between the polar component (Δγsp) and the difference between the hydrogen bond components (Δγsh) (Δγsd + Δγsp)
+ Δγsh) is 20 mN / m or less and any extrudable thermoplastic resin may be used. Specifically, ethylene propylene rubber (EPDM), ethylene vinyl acetate, ethylene ethyl acrylate, ethylene methyl acrylate , Styrene butadiene rubber, polyester, polyurethane, polyamide (nylon 6, nylon 66, nylon 11, nylon 12, and other copolymerized nylons), styrene ethylene butyl, ethylene butyl, nitrile butadiene rubber, chlorosulfonated polyethylene, polysulfide rubber Ordinary rubbers such as chlorinated polyethylene, chloroprene rubber, butadiene rubber, 1,2-polybutadiene, isoprene rubber and polynorbornene rubber, and styrene-butadiene-styrene (SB
S) and thermoplastic rubbers such as styrene-butadiene-styrene water additive (SEBS) can be used;
There is no particular limitation.

Alternatively, elastomers such as the above-mentioned resins and copolymers and modified elastomers, and polyethylene, polypropylene, polyethylene terephthalate (PET) and polybutylene terephthalate (PBT)
Such as saturated polyester, polyether, polyamide, polycarbonate, polyacetal, acrylonitrile butadiene styrene, polystyrene, high impact polystyrene (HIPS), polyurethane, polyphenylene oxide, polyvinyl acetate, polyvinylidene fluoride,
Polytetrafluoroethylene, acrylonitrile-butadiene-styrene resin (ABS), acrylonitrile-
Ethylene / propylene rubber-styrene resin (AES) and acrylonitrile-acrylic rubber-styrene resin (A
A combination of a resin and a material made of a copolymer such as a styrene resin such as AS), an acrylic resin, a vinyl chloride resin and a vinylidene chloride resin is preferable.

Next, the functional multilayer film used in the present invention will be described. The functional multilayer film in the present invention is a polymer previously formed in the form of a seamless tube, and is externally fitted to and covered by the foamed elastic material layer on the outer periphery of the core metal (metal layer).

For example, a desired number of functional multilayer films 3 can be formed by a single operation using the apparatus shown in FIG.
2 (a) is for two types and two layers, (b) is for two types and three layers,
(C) is for three types and three layers.

The resin, elastomer, copolymer and the like used in this case are as described above, and a tube structure having desired characteristics can be obtained by appropriately blending a conductive material described later. Further, a polymer alloy or a polymer blend composed of two or more polymers selected from the above rubber, thermoplastic elastomer and thermoplastic resin can also be used.

The tube of the functional multilayer film of the present invention can be prepared by extrusion molding, injection molding, or the like of the above polymer and a conductive polymer composition comprising the following conductive materials and other additives as necessary. It can be obtained by forming a film into a tube by a blow molding method or the like. Among the above various molding methods, the extrusion molding method is particularly preferred.

Further, in order to obtain a uniform thickness of each thin film layer of the tube to be formed and a more uniform dispersibility of the conductive material and the like, a vertical tube extruder (FIG. 3) is used. I do.

As the conductive material, known materials can be used, for example, carbon fine particles such as carbon black and graphite; metal fine particles such as nickel, silver, aluminum and copper; tin oxide, zinc oxide, titanium oxide, and the like. Conductive metal oxide fine particles containing aluminum oxide and silica as main components and doped with impurity ions having different valences; conductive fibers such as carbon fibers; metal fibers such as stainless steel fibers; carbon whiskers and potassium titanate whiskers Conductive whisker such as conductive potassium titanate whisker whose surface is made conductive with metal oxide or carbon; and conductive polymer fine particles such as polyaniline and polypyrrole.

Each layer of the functional coating film used in the present invention is composed of the above-mentioned material, and the difference (Δγ) in the dispersion component of the surface free energy of the layers in contact with each other in the functional multilayer tube.
sd) and the difference between the polar component (Δγsp) and the difference between the hydrogen bond components (Δγsh) (Δγsd + Δγsp + Δγsh)
Is 20 mN / m or less. If it is more than 20 mN / m, compatibility or conformability between the multilayer tubes becomes poor,
It is difficult to make the adhesive force described below 200 n / m or more. Along with this, it is not preferable because the prescription can be restricted and other physical properties of the charging roller may be affected.

Each layer of the functional multilayer film used in the present invention is composed of the above-mentioned material, and the adhesion between the layers of the functional multilayer tube is preferably 200 N / m or more.
If it is less than 200 N / m, the adhesion between the multilayer tubes becomes insufficient, and resistance unevenness occurs. Furthermore, by heat-treating the multilayer tube, it is possible to increase the adhesion and reduce resistance unevenness due to insufficient adhesion.

The resistance value of the functional multilayer film used in the present invention is preferably from 1 × 10 ⁴ to 1 × 10 ⁸ Ω · cm, and particularly preferably from 1 × 10 ⁵ to 1 × 10 ⁷ Ω · cm. It is preferred that

The functional multilayer film used in the present invention can be formed by various methods, but the extrusion method is preferable as described above. That is, a compound in which a polymer, a conductive material and, if necessary, a cross-linking agent, a stabilizer and other additives are mixed is manufactured, and the compound is extruded from a die having a ring-shaped slit by an extruder and cooled. Thus, a seamless tube can be manufactured continuously (FIG. 3).

In the case of a non-heat-shrinkable tube, the inner diameter of the tube must be smaller than the outer diameter of the foamed elastic layer in order to ensure the adhesion between the foamed elastic layer and the functional multilayer film. The outer fitting process is completed by inserting a foamed elastic body layer having a metal core with the tube diameter expanded by blowing compressed air and releasing the air pressure.

Next, an extruder used in the present invention will be described with reference to FIG. The die 4 used for molding is provided with inner and outer double annular extrusion channels 6 and 7 around a central through hole 5 for air introduction. An elastomer for the inner layer constituting the functional multilayer film from the first extruder 8 is added to the passage 6, and an elastomer for the outer layer constituting the functional multilayer film from the second extruder 9 is added to the outer channel 7. Pressure injection, inner layer 3
While the inside of the tube 3 of the functional multilayer film obtained by superposing and integrating the outer layer 3 (o) with the outer layer 3 (o) is inflated with air, it is cooled by a water cooling ring 10 provided on the outer periphery thereof, This is pulled by a tube feeder and cut into a predetermined length in order, and is coated on a foamed elastic layer having a core metal in the next step as a functional multilayer film for a charging roller. FIG.
Medium, 22 of the tube feeder is a timing pulley, 2
3 is a feed belt.

[0037] In the present invention, for example, 1 × 10 ⁵ ~1 × resin layer of the resistance of 10 ⁶ Omega order to have a pressure resistance is arranged outside ^{layer, 1 × 10 4 ~1 × 10} 6 Ω within layer It is easy to arrange this resin layer, and it becomes an ideal functional multi-layer film for a roller such as a charging roller which needs to control the surface potential of the roller.

The functional multilayer film is composed of two layers, an inner layer and an outer layer, and the resistance Rr of the charging member is 0.01 MΩ <Rr <1.
It is preferably MΩ. If the resistance is less than 0.01 MΩ, a high voltage is applied, so that a problem is likely to occur in the pressure resistance.
Above MΩ, a current sufficient to charge the electrophotographic photosensitive member does not flow, and charging failure is likely to occur.

The inner diameter of the tube 3 of the functional multilayer film obtained by the present invention is not particularly limited, and is determined by the outer diameter of a roller using the same.
It is common to use a small diameter tube of 0 mm.

When a charging roller or a developing roller is manufactured by using the functional multilayer film tube 3 obtained by the present invention, a foamed elastic material layer is previously formed on the outer periphery of the metal core 1 as shown in FIG. The tube 3 of the functional multi-layer film may be fitted around the outer periphery of the roller coated with 2.

In this fitting, it is preferable that the inner diameter of the functional multi-layer tube 3 is slightly smaller than the outer diameter of the foamed elastic layer 2 because wrinkles and the like do not occur in the finished roller. Outer diameter of 1
When the thickness of the functional multilayer tube 3 is 2.0 mm and the thickness of the functional multilayer tube 3 including the inner and outer layers is 0.1 mm, the outer diameter of the foamable elastic layer having the core metal is set to 11.9 mm, and the thickness of the functional multilayer film is increased. Tube 3
Is preferably about 11 mm.

Further, when the functional multi-layer tube 3 is fitted, it may be bonded to the inner surface or the outer periphery of the roller by applying a primer if necessary. Is also possible.

(Function) Since the functional multi-layer tube 3 is integrally formed into a multi-layer structure by vertical extruder molding for simultaneously extruding the inner and outer layers, the function is separated into the inner and outer layers so that the wall thickness is sufficient and sufficient. It is possible to obtain a resistance layer corresponding to a wide range of resistance values required for the design of the charging roller. Further, by controlling the value of the surface free energy of each layer, it is possible to produce a roller having a sufficient strength that the adhesion of each layer can be cut off at the time of coating and use and a uniform resistance value.

[0044]

The present invention will be described below in more detail with reference to specific examples.

<When the functional multilayer film is composed of a resistance adjustment layer / a conductivity control layer> The resistance adjustment layer may be made of a resin whose material itself has an appropriate resistance value, or may be made of carbon or conductive metal. A resin whose resistance value is adjusted by mixing conductive powders such as oxides may be used. By simultaneously extruding these respective layer materials, an integrated multi-layer functional tube can be formed. In the present invention, the tube is formed using a vertical extrusion device. In horizontal extrusion equipment,
Since the flow direction of the extruded tube is orthogonal to the gravity, the effect of gravity acts in the circumferential direction of the tube, especially in the soft state immediately after being extruded, so that it is used in the present invention. It was considered to lack definition for electrophotographic applications.

(Example 1) <Core metal> The core metal was formed by extruding an iron material to a diameter of 5 mm.
Was extruded into a bar material, and cut into a length of 260 mm, and a material obtained by applying a chemical plating to the resultant material to a thickness of about 3 μm was prepared.

<Forming of foamed elastic layer>
A hose-shaped foamed elastic body layer having an outer diameter of 11.5 mm [Ethylene-propylene-diene rubber (EPDM) is compounded with a vulcanizing agent and a foaming agent, and the mixture is formed into a hose shape by an extruder. Foamed in a vulcanizing can] with a length of 2
Cut into 25mm, the center hole, the above-mentioned diameter 5mm,
A core bar having a length of 260 mm was inserted.

<Tube molding of functional multilayer film> As a material for the outer layer of the functional multilayer film, a styrene-based resin (styrene-ethylene / butylene-olefin copolymer resin, trade name: Dinalon, manufactured by JSR Corporation) 100 parts by mass, 20 parts by mass of polyethylene and 15 parts by mass of carbon black (trade name: Ketjen Black EC, manufactured by Lion Akzo) were mixed for several minutes by a V-type blender. This was further melt-kneaded at 190 ° C. for 10 minutes using a pressure kneader. Furthermore, after cooling, it was pulverized by a pulverizer and pelletized by a single screw extruder.

As materials for the inner layer, 90 parts by mass of a polyurethane elastomer, 10 parts by mass of polyethylene, 15 parts by mass of carbon black (Ketjen Black EC), 10 parts by mass of magnesium oxide and 1 part by mass of calcium stearate
Parts by mass were pelletized in the same process as the material of the outer layer.

Vertical extruder (custom-made product from Plagiken Co., Ltd., FIG. 3)
Using a single crosshead so as to form a double layer, and hot water (40 ° C. to 90 ° C.)
0, further cooled and taken off (22 and 2
3). Thus, a tube of a functional multilayer film having an outer diameter of about 11 mm was obtained.

The surface free energy of each layer of the tube was measured using three types of liquids having known surface free energies on the surface of each layer, and the contact angles were measured to determine each component of the surface free energy. Specifically, the measurement was performed using water, ethylene glycol and diiodomethane. Table 1 shows the results of the surface free energy.

For the measurement of the adhesion between the tube layers, the multilayer tube was cut open in the longitudinal direction, part of the tube was peeled off, and a T-peel strength was determined using a load cell according to JIS-K6854. Table 2 shows the results of the adhesion.

<Production of Roller> Outer Diameter 1 with Core Inserted
A 1.5 mm, 225 mm long hose-shaped foamed elastic layer was heat-treated into a functional multi-layer tube 3 of 230 mm.
The cut into lengths was fitted around the outer periphery of the foamed elastic layer by a tube covering device (not shown) and brought into pressure contact. The electric resistance of the charging member is obtained by applying a voltage of 200 V to the roller and calculating the resistance value Rr from the current value I flowing at this time according to the formula R
r = V / I. Table 2 shows the resistance Rr of the roller. The resistance value Rr of the charging roller of Example 1 is 0.01 M
Ω to 1 MΩ.

An image was formed using this charging roller as a primary charger of an LBP (laser beam printer; Laser Jet 2-P manufactured by Hewlett-Packard Company). As a result, the functional multilayer film 3 and the foamed elastic layer 2 were formed. No gaps are generated between the functional multilayer films 3 without wrinkles,
Good images were obtained.

(Example 2) In the inner layer of Example 1,
90 parts by mass of polyurethane elastomer, 10 parts by mass of ethylene-vinyl acetate copolymer, 15 parts by mass of carbon black (Ketjen Black EC), 10 parts of magnesium oxide
Parts by mass and 1 part by mass of calcium stearate were pelletized in the same process to prepare a charging roller. Table 1 shows the results of the surface free energy. Table 2 shows the results of the adhesion between the layers of the functional multilayer tube and the resistance Rr of the charging roller. As a result of performing image evaluation in the same manner as in Example 1 using the charging roller, a good image was obtained.

(Comparative Example 1) In the inner layer of Example 1,
100 parts by mass of a polyurethane elastomer, 15 parts by mass of carbon black (Ketjen Black EC), 10 parts by mass of magnesium oxide, and 1 part by mass of calcium stearate were pelletized in the same process to prepare a charging roller. Table 1 shows the results of the surface free energy. Table 2 shows the results of the adhesion between the layers of the functional multilayer tube and the resistance Rr of the charging roller.

As a result of performing image evaluation in the same manner as in Example 1 using the above-mentioned charging roller, there was no problem in the initial image. However, under the high temperature and high humidity (32.5 ° C./85% RH) environment or low temperature and low humidity ( Under an environment of (15 ° C./10% RH), image defects appeared as the number of output images increased, and became remarkable when the number exceeded 1,000. However, in the case of 1000 sheets which could not be judged, images were output up to 4000 sheets and confirmed.

Further, when the local resistance Rr of the charging roller was measured in the same manner as in Example 1, it was found that it was more uneven than in Example 1.

The irregularities on the surface of the charging roller are described in
No problem was observed in both Comparative Examples.
By the way, in the case of the sample having a large Rr, the electric resistance in the form of the charging member becomes large, and the applied voltage must be higher than the originally designed value. Since a voltage is applied to the substrate, there is a problem in the pressure resistance.

[0060]

[Table 1]

[0061]

[Table 2]

FIG. 4 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the charging member of the present invention.

In the figure, reference numeral 13 denotes an electrophotographic photosensitive member which is driven to rotate at a predetermined peripheral speed in the direction of the arrow. The electrophotographic photosensitive member 13 receives a uniform charge of a predetermined positive or negative potential on the peripheral surface thereof by the charging member 1 ′ of the present invention during the rotation process, and then exposes the photosensitive member 13 to an exposure unit such as a slit exposure or a laser beam scanning exposure. (Shown). Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the electrophotographic photosensitive member 13.

The formed electrostatic latent image is then transferred to developing means 1
5, and the developed toner image is
An electrophotographic photosensitive member 13 and a transfer unit 16
The transfer means 16 sequentially transfers the transfer material 17 taken out and fed in synchronization with the rotation of the electrophotographic photosensitive member 13 during the transfer.

The transfer material 17 which has undergone the image transfer is separated from the electrophotographic photosensitive member surface, introduced into the image fixing means 18 and subjected to image fixing, thereby being printed out as a printed matter (copy, print) outside the apparatus.

The surface of the electrophotographic photosensitive member 13 after the image transfer is
The transfer residual toner is removed by the cleaning unit 19 to be cleaned and is used for repeated image formation.

In the present invention, the electrophotographic photosensitive member 13
Of the above-mentioned components such as the charging member 1 ', the developing means 15 and the cleaning means 19, a plurality of components are housed in a process cartridge container 21 and integrally connected as a process cartridge. It may be configured to be detachable from an electrophotographic apparatus main body such as a beam printer. For example, developing means 1
5 and the cleaning means 19 are integrally supported together with the electrophotographic photoreceptor 13 and the charging member 1 'to form a cartridge, and a process cartridge detachably mountable to the apparatus main body using a guide means 20 such as a rail of the apparatus main body. it can.

When the electrophotographic apparatus is a copying machine or a printer, the exposure light 14 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal.
Laser beam scanning performed according to this signal, LE
The light is emitted by driving the D array or driving the liquid crystal shutter array.

As described above, the evaluation was performed by the image forming apparatus using the process cartridge in which the charging members of Examples 1 and 2 and Comparative Example 1 were incorporated.

[0070]

As described above, in the charging member of the present invention, by adjusting the surface free energy of each layer, the adhesion of the multilayer tube becomes sufficient, and the local unevenness is small.
It has excellent properties such as good surface smoothness.

Further, according to the process cartridge and the electrophotographic apparatus having the charging member, it is possible to maintain a good image output without image defects for a long period of time from low temperature and low humidity to high temperature and high humidity.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conductive roller of the present invention.

FIG. 2 is an extrusion apparatus for simultaneously forming a multilayer tube.
(A) for two types and two layers, (b) for two types and three layers, (c) for three types
For seed 3 layers

FIG. 3 is a vertical extrusion molding apparatus for simultaneously molding a multilayer tube.

FIG. 4 is a cross-sectional view of an electrophotographic apparatus having a process cartridge having a conductive roller of the present invention.

[Explanation of symbols]

 Reference Signs List 1 'conductive roller 2 foamed elastic layer 3 functional multilayer film 4 die 5 central through hole 6,7 flow path 8 first extruder 9 second extruder 10 water cooling ring 12 power supply 13 electrophotographic photosensitive member 14 exposure light 15 Developing unit 16 Transfer unit 17 Transfer material 18 Fixing unit 19 Cleaning unit 20 Guide unit 21 Process cartridge container 22 Timing pulley 23 Feed belt

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kyoko Suzuki 1888-2 Kusazaki, Kusazaki-cho, Inashiki-gun, Ibaraki F-term in Canon Chemical Co., Ltd. (reference) 2H003 BB11 CC05

Claims (5)

[Claims] 1. A multi-layer tube obtained by simultaneously forming a core, a foamed elastic layer on the outer periphery of the core, and a plurality of functional films is coated on the outer periphery of the foamed elastic layer. The difference between the dispersion component (Δγsd) of the surface free energy, the difference between the polar components (Δγsp), and the difference between the hydrogen bond components (Δγsd) of the layers in contact with each other in the functional multilayer tube.
h) is 20 m (Δγsd + Δγsp + Δγsh)
N / m or less. 2. The charging member according to claim 1, wherein the adhesion between the layers of the functional multilayer tube is 200 N / m or more. 3. The functional multi-layer tube comprises an inner layer and an outer layer, and the charging member has a resistance Rr of 0.0.
The charging member according to claim 1, wherein 1MΩ <Rr <1MΩ. 4. A process which integrally supports an electrophotographic photosensitive member and a charging member, or one or both of an electrophotographic photosensitive member, a charging member, a developing unit, and a cleaning unit, and is detachable from the main body of the electrophotographic apparatus. In the cartridge,
The charging member is a charging member that is arranged in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member by applying a voltage, and the charging member according to any one of claims 1 to 3. A process cartridge, comprising: 5. An electrophotographic photosensitive member, a charging member, an exposure unit,
In an electrophotographic apparatus having a developing unit and a transfer unit,
The charging member is a charging member that is arranged in contact with the electrophotographic photosensitive member and charges the electrophotographic photosensitive member by applying a voltage, and the charging member according to any one of claims 1 to 3. An electrophotographic apparatus, comprising: