JPH0571805B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a conductive elastic roller having conductivity between a core metal and a roller surface, such as a charging roller, a transfer roller, etc. used in an electrophotographic device; The present invention relates to a manufacturing method thereof.

[Prior Art] Conventionally, there is a type of conductive elastic roller having electrical conductivity in which a metal core and a roller surface are electrically connected, as shown in FIG. 18, for example.

This is a single-layer elastic roller in which a conductive filler is added to an elastic roller part 2 provided around a core metal 1, and this elastic roller part 2 is made of an unvulcanized synthetic rubber material with a conductive filler such as conductive carbon. It is manufactured by adding and kneading the mixture so that it has a predetermined conductivity, forming it into a roller shape, and then heating and vulcanizing it.

In addition, such a single-layer conductive elastic roller is made by injection molding using a thermoplastic elastomer material for the elastic roller portion 2 and kneading a conductive filler such as conductive carbon in the same manner. A manufacturing method has been proposed.

On the other hand, FIG. 19 shows a two-layer structure in which a non-conductive elastic roller part 3 is provided around the mandrel 1, and a conductive layer 4 is further provided on the surface of the elastic roller part 3, which is electrically connected to the mandrel 1. This is a conductive elastic roller, and the elastic roller part 3 is vulcanized and molded from ordinary synthetic rubber material or injection molded from thermoplastic elastomer, and the surface of the elastic roller part 3 is coated with a conductive paint having the required conductivity. The conductive layer 4 is formed by coating, at which time,
A conductive paint is also applied to the adhesion parts 3a and 3b to the core 1 to provide conductivity between the core 1 and the roller surface.

[Problems to be Solved by the Invention] By the way, in the conductive elastic roller having a single layer structure in which a conductive filler is added to the conductive roller portion 2 shown in FIG. 18, the amount of conductive carbon added in order to obtain the required conductivity is The greater the number, the higher the hardness of the material.

In other words, there is a lower limit to the hardness of a synthetic rubber material without the addition of conductive carbon due to problems such as material strength and seepage of plasticizer, and as a result, the lower limit of the surface hardness of the conductive roller becomes even higher than that. For example, JISK6301 A hardness, which is the softest category, has a hardness of around 30 degrees.
Made of EPDM rubber with core diameter φ6mm and roller diameter φ12mm.
If the resistance value between the core metal and the roller surface is made conductive to 10 ⁶ - 10 ⁷ Ω, the roller will have a hardness of around 40 degrees, and if a thermoplastic elastomer with a hardness of around 15 degrees, which is the softest class, is used, A similar conductivity process results in a roller with a hardness of around 40 degrees.

Here, such a single-layer conductive elastic roller is used as a charging roller for directly contacting a photoreceptor drum and charging the surface of the photoreceptor drum in an image forming apparatus such as an electrophotographic copying apparatus. In this case, the charging roller rotates in contact with the surface of the photoreceptor drum, so if the roller has a hardness of 40 degrees or more, vibration noise tends to increase when AC voltage is applied to charge the drum. . Furthermore, when used as a transfer roller that comes into direct contact with transfer paper to transfer the toner image formed on the surface of the photoreceptor drum, rollers with high hardness of 40 degrees or more tend to cause transfer defects. .

For this reason, a conductive roller with lower hardness is required for the charging roller and the transfer roller, but it has not been possible to obtain a satisfactory conductive elastic roller having a single layer structure.

On the other hand, the conductive elastic roller with a two-layer structure made of conductive paint shown in FIG. 19 solves the problem of increased hardness that was a problem with the single-layer structure, but since the conductive layer 4 is applied and formed in a secondary processing step, The number of steps increases by one, and painting requires equipment for environmental protection such as solvent treatment, which increases costs. Furthermore, the electrical connection between the core metal 1 and the roller surface is achieved by the adhesive portions 13a, 1
3b, there was a high risk that the electrical connection would be broken due to elastic deformation of the elastic roller portion 3 or the like.

An object of the present invention is to provide a conductive elastic roller that has low hardness, can maintain strong electrical connectivity with the metal core without being affected by elastic deformation, and can be manufactured with fewer man-hours, and its manufacture. The purpose is to provide a method.

[Means and effects for solving the problems] The gist of the conductive elastic roller for achieving the object of the present invention is a thin-walled thermoplastic elastomer fixed around a core metal and a conductive filler added thereto. a thick non-conductive core layer made of a thermoplastic elastomer formed around the first conductive layer, and a thermoplastic elastomer formed around the core layer that is conductive. a thin second conductive layer added with a filler, and a thermal conductive layer formed integrally with both conductive layers along the length thereof between the first conductive layer and the second conductive layer. A conductive elastic roller comprising one or more thin connecting walls made of a plastic elastomer and a conductive filler added thereto.

In addition, a thin first conductive layer made of a thermoplastic elastomer with a conductive filler added to the core metal, and a thick non-conductive layer made of a thermoplastic elastomer formed around the first conductive layer. a thin second conductive layer formed around the core layer and formed by adding a conductive filler to a thermoplastic elastomer, and the first conductive layer and the second conductive layer A conductive elastic roller characterized in that one end thereof is connected.

In addition, the gist of the method for manufacturing a conductive elastic roller is that the skin layer material is a thermoplastic elastomer with a conductive filler added, the core layer material is a thermoplastic elastomer to which no conductive filler is added, and the core layer material is a thermoplastic elastomer with no conductive filler added. The skin layer material is injected by the Sandersch injection molding method using a mold that is previously supported in a predetermined position, and then the core layer material is injected, and the core layer material is surrounded by the skin layer material. are surrounded and merged from one direction or multiple directions along the periphery of the mandrel, and a thin first layer is formed around the mandrel by the skin layer material.
a thick non-conductive core layer surrounding the first conductive layer by a core layer material, and a thin second conductive layer surrounding the core layer by a skin layer material;
A three-layer structure comprising one or more thin-walled connecting walls connecting the first conductive layer and the second conductive layer along their lengths using a skin layer material. A method of manufacturing a conductive elastic roller is characterized in that the structured roller is molded in one step.

In addition, the skin layer material is a thermoplastic elastomer with a conductive filler added, the core layer material is a thermoplastic elastomer without the addition of a conductive filler, and a mold with a mandrel pre-supported in a predetermined position is used to create a sandwich. After injecting the skin layer material by an injection molding method, the core layer material is injected, and a package of fluid resin portion in which the core layer material is wrapped by the skin layer material is axially from one end side of the mandrel. A thin first conductive layer is formed around the mandrel by the skin layer material, a thick non-conductive core layer is formed around the first conductive layer by the core layer material, and a skin layer material is poured along the core. A thin second conductive layer is provided around the core layer, and the other ends of the first conductive layer and the second conductive layer are connected by a skin layer material so as to cover the other end surface of the core layer. A method of manufacturing a conductive elastic roller is characterized in that a roller having a three-layer structure including a connecting end portion and a connecting end portion is formed in one step.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

<Example 1> FIG. 1 is a perspective view showing Example 1 of the conductive elastic roller according to the present invention.

Reference numeral 10 denotes a thin conductive first skin layer made of a thermoplastic elastomer with a conductive filler added thereto, and is fixed to the outer periphery of the mandrel 1.
Reference numeral 11 denotes an electrically conductive core layer made of a thermoplastic elastomer containing no electrically conductive filler, which forms the core of the elastic roller portion, and is formed in a thick layer on the outer peripheral surface of the first skin layer 10 . A thin second conductive skin layer 12 is made of the same resin as the first skin layer 10 and is formed on the outer peripheral surface of the core layer 11 . 13 is the first,
A thin connection wall made of the same resin as the first and second conductive skin layers 10 and 12 that electrically connects the second conductive skin layers 10 and 12, and is an axis inside the core layer 11. along the direction of the first conductive skin layer 10
and the second conductive skin layer 12,
The end face of the cut in the axial direction is formed into the illustrated end face shape at any position.

Core layer 11 made of thermoplastic elastomer resin
Since no conductive filler is added and the hardness of the thermoplastic elastomer resin can be set to any desired hardness by selecting the material, the core layer 11 can be made to have a low hardness. In addition, a first conductive skin layer 10, a second conductive skin layer 12
Since the connecting wall portion 13 is made of a thermoplastic elastomer resin with a conductive filler added, its hardness is higher than that of the thermoplastic elastomer used, but since both are formed thin, the conductive elasticity It has almost no effect on the hardness of the entire roller, and the hardness of the entire conductive elastic roller is lower than that of the core layer 1.
The hardness can be approximately equal to the hardness of No. 1.

That is, in the conductive elastic roller of this embodiment, the second conductive skin layer 12 forming the outer peripheral surface of the roller is bonded to the core metal 1.
It is electrically connected to the first conductive skin layer 10 fixed to the outer circumferential surface of the first conductive skin layer 10 through a connecting wall 13, and the connecting wall 13 extends over its entire length between both conductive skin layers 10 and 12. Since it is integrally molded, it is possible to obtain the desired hardness without causing conductivity defects due to elastic deformation or the like.

Next, an embodiment of the method for manufacturing the conductive elastic roller according to this embodiment will be described with reference to FIGS. 2 to 4.

In FIG. 2, 20 and 21 are split molds for injection molding, and both split molds 20, 21
A cavity 22 for forming an elastic roller portion is formed around the core metal 1 by fitting and fixing both ends of the core metal 1 with the mold matching surface as the axis,
A runner 23 is formed on the upper part of the split mold 21 on the fixed side to supply injection molded resin to the cavity 22 perpendicularly to the axis of the mandrel 1, as shown in A-A in FIG.
The arrow view is as shown in Figure 3a.

The injection molding machine to which the split molds 20 and 21 are installed continuously supplies two types of resin to the cavity 22, with the first supplied resin (hereinafter referred to as scan layer material) and the second supplied resin ( This is an injection molding machine for the so-called Sanderutsch molding method, which can wrap the core layer material (hereinafter referred to as core layer material).

First, as shown in FIG. 3b, an appropriate amount of the skin layer material 24, which is made by adding a conductive filler to a thermoplastic elastomer to obtain the required conductivity, is injected into the runner 23, and then a non-conductive filler made of a thermoplastic elastomer is injected into the runner 23. Injection of conductive core layer material 25 into runner 23 begins. Note that the core metal 1 is coated with a thermoplastic elastomer and a hot melt type adhesive with good adhesion on the outer circumferential surface of the split mold 20, 2.
It is installed on 1.

When the core layer material 25 is injected into the runner 23, the skin layer material 24 forms a thin skin layer on the inner wall surface of the runner 23, the inner peripheral wall surface of the cavity 22, and the outer peripheral surface of the mandrel 1, as shown in FIG. 3b. While forming, the core layer material is expanded along the circumferential direction and the axial direction of the mandrel 1, and in the circumferential direction of the mandrel 1, it is divided into two parts so as to surround the mandrel 1 from the runner 23 side, and further, the core When the layer material 25 is injected, the tips of the skin layer divided into two parts go around to the opposite side of the runner 23, and finally, as shown in FIG. The tip portions merge to form a thin merging portion on one side along the axial direction.

That is, in the split molds 20 and 21, as shown in FIG. 10, a second conductive skin layer 12, and a connection wall 13 between the first conductive skin layer 10 and the second skin layer 12 are integrally formed on the inner peripheral surface of the cavity 22, and the core The layer material 25 simultaneously forms a non-conductive core layer 11 surrounded by the first conductive skin layer 10 and the second conductive skin layer 12 . Then, by opening the split molds 20 and 21 and taking out the molded roller together with the runner from the mold, and cutting off the excess molded part molded in the resin injection part, one layer is added to which the conventional conductive filler is added. The conductive elastic roller shown in FIG. 1 with a low hardness, for example, 40 degrees or less, which could not be obtained with the conductive elastic roller of this structure, can be obtained in one molding process.

By setting the molding conditions such as the ratio of the skin layer material 24 and the core layer material 25, temperature, injection pressure, etc., as shown in FIG. The core layer 11 made of the core layer material 25 can be left exposed without being wrapped with the skin layer material 24, or can be wrapped with the skin layer material 24 as shown in FIG. By wrapping the ends of the rollers and electrically connecting the first conductive skin layer 10 and the second conductive skin layer 12, the first conductive skin layer 10 and the second conductive skin layer 12 are connected to each other. It is possible to further improve the electrical conductivity between the two.

Therefore, according to the manufacturing method of this embodiment, the conductive roller is completed in one molding process, so that
This increases the number of steps, which was a problem with the conventional conductive elastic roller having a two-layer structure made of conductive paint. Problems such as high costs will be solved.

Further, the length of the connection wall portion that electrically connects the first conductive skin layer 11 and the second conductive skin layer 12, which is formed by the confluence of the resin of the skin layer material, is approximately equal to the longitudinal dimension of the roller. , is formed reliably in contact with the core metal 1, so there is no risk of disconnection of the electrical connection, which was a problem with the two-layer structure made of conductive paint, and reliability has been dramatically improved.

<Example 2> FIG. 6 shows a perspective view of a conductive elastic roller of Example 2.

The conductive elastic roller of Example 1 shown in FIG. Although the connection is made by the wall portion 13, the conductive elastic roller of this embodiment has the connecting wall portions 13, 13 provided at axially symmetrical positions of the mandrel 1, and the 2
The first electrically conductive skin layer 10 is connected by a surface connecting wall 13.
and the second conductive skin layer 12, and the cross-sectional shape of the cut end in the axial direction has the shape of the end face of the roller shown in FIG. 6 at any position.

Therefore, according to this embodiment, since both the conductive skin layers 10 and 12 are connected by the two connection walls 13, the conductive skin layers 10 and 12 of both the conductive skin layers 10 and 12 are
This makes it possible to further improve the conductivity between the two.

Next, an embodiment of a method of manufacturing a conductive elastic roller having two connection wall portions according to this embodiment will be described with reference to FIGS. 7 to 11.

In FIG. 7, numerals 30 and 31 are split molds that are installed in the injection molding machine for the above-mentioned sandwich molding method, and the mandrel 1 is fitted into upper supports 32 and 33 provided on the upper part of the mold mating surface. At the same time, it is fixed by fitting into lower fixing grooves 34 and 35 provided at the lower part. When both split molds 30 and 31 are closed, cavities 36 are provided on both sides of the upper supports 32 and 33, respectively, as shown in the front view of the fixed side split mold 30 in FIGS. 7b and 8. A first resin flow path 37 and a second resin flow path 38 that communicate with each other are formed axially symmetrically, and these first resin flow paths are connected to a runner 39 formed in the split mold 31 on the fixed side. 36, and second resin flow path 39
are in communication, the resin from the runner 39 is once divided into two resin flows in the first and second resin flow paths 37 and 38, and then the resin flows through the cavity 36.
I'm trying to merge them inside.

Runner 39 of the split mold 31 formed in this way
First, an appropriate amount of the skin layer material 24 is injected in the same manner as in Example 1 described above, and then the core layer material 24 is injected.
Start injection of 5. The skin layer material 24 is expanded by the core layer material 25 injected later, forming a thin skin layer on the mold surface in the split mold, and flowing through the first resin flow path 37 and the second resin flow path. Head towards Route 38. The skin layer material 24 that has been pushed and spread by the core layer material 25 until just before reaching the first resin flow path 37 and the second resin flow path 38 is
The core layer material 25 is packaged in one package, and this first
By passing through the resin flow path 37 and the second resin flow path 38, the core layer material 2 is formed by the skin layer.
5 flows into the cavity 36, and the resin flowing parts of the second wrap flow downward in the axial direction while surrounding the outer circumference of the mandrel 1 from an axially symmetrical position, and flow into the cavity 36. Filled. Then, the two wrapped resin flowing parts wrap around the outer circumference of the mandrel 1 from an axially symmetrical position, and both end portions of the resin flow parts wrap around and join each other at a substantially axially symmetrical position of the mandrel 1, and the skin layer Two thin merging portions made of material 24 are formed. That is, in the split molds 30 and 31, as shown in FIGS. 9 and 10, the first conductive skin layer material 24 is injected to form the first conductive skin layer 10 on the outer periphery of the mandrel 1. , a second conductive skin layer 12 and two connecting walls 13 between the first conductive skin layer 10 and the second conductive skin layer 12 are integrally formed on the inner peripheral surface of the cavity 36. , core layer material 2
5, the non-conductive core layer 11 is separated by a pair of connecting walls 13 into the first conductive skin layer 1.
0 and the second conductive skin layer 12 at the same time. Then, by opening the split molds 30 and 31 and taking out the molded roller together with the runner from the mold, and cutting off the excess molded part molded in the resin injection part with a cutter or the like, the conductive elasticity shown in FIG. You will get a roller.

When the conductive elastic roller of this example formed in this way was used as a charging roller in an electrophotographic apparatus, when an alternating current voltage was applied to charge the photoreceptor drum, the conventional conductive elastic roller shown in FIG. The vibration noise generated by the elastic roller was 51 dB for a roller with a hardness of 40 degrees, but the hardness of the roller in this example can be reduced to 15 degrees, which reduces vibration noise.
This was significantly reduced to 45dB. Furthermore, when used as a transfer roller, transfer defects occurred with the conventional roller with a hardness of 40 degrees, but this did not occur with the roller of this embodiment with a hardness of 15 degrees.

<Example 3> FIG. 12 shows a conductive elastic roller of Example 3.

In the first and second embodiments described above, the skin is integrally formed between the first conductive skin layer 10 and the second conductive skin layer 12 formed on the outer periphery of the mandrel 1 along the axial direction of the mandrel 1. Although the connection is made by a connection wall 13 formed of a layer material, in this embodiment, the first conductive skin layer 10 and the second conductive skin layer 12
are connected at one end by a skin layer material, and the core layer 11 is wrapped between both conductive skin layers 10, 12 as shown in the cross-sectional shape shown in FIG. 12a, and both conductive skin layers 10, 12 are electrically connected at one end thereof.

Next, a method for manufacturing the conductive elastic roller according to this example will be explained based on FIG. 13.

In FIG. 13, only the lower end of the mandrel 1 installed and fixed in the split molds 40, 41 is attached to the holding part 4.
The resin flow path 42 is formed around the upper part of the mandrel 1 which extends upward and is supported and fixed by the mandrel 1.
No holding part is provided in the resin flow path 42, and resin from a runner 43 provided above the resin flow path 42 is supplied to the cavity 44 through the resin flow path 42.

That is, the ratio of the amount of skin layer material 24 to the amount of core layer material 25 is determined in advance so that the skin layer is formed in the runner 43 at the outermost end 45 of the cavity on the opposite side of the resin injection port. As in the case of , first the skin layer material 24 is injected into the runner 43 and then the injection of the core layer material 25 is started.
The skin layer material 24 forms a skin layer on the inner surfaces of the split molds 40 and 41 and the outer surface of the mandrel 1, and a package of resin flow portion surrounding the core layer material 25 with the skin layer flows from the resin flow path 42. Cavity 4
4, a skin layer of the skin layer material 24 is formed around the mandrel 1 and the entire inner wall surface of the cavity 44 so as to wrap around the core layer material 25, and as in the above embodiment, Core deposit 1
Since the skin layer material 24 does not flow so as to surround the periphery in the radial direction, the skin layers never merge with each other in the axial direction of the mandrel 1. Therefore, as in each of the above embodiments, First conductive skin layer 10 and second conductive skin layer 12
A connection wall portion 13 for electrically connecting in the axial direction between the two is not formed.

As shown in FIG. 12, in a conductive elastic roller in which one end of the roller is covered with a skin layer material 24 and both conductive skin layers 10 and 12 are electrically connected, the effective portion extends to both ends of the roller. For example, when used in a charging roller or a transfer roller of an electrophotographic copying device, the hardness of the skin layer material 24 is higher due to the effect of the conductive filler, so the hardness of one end of the roller is higher than that of other parts. As shown in Figures 14 and 15, a roller is formed at one end of the roller as shown in Figures 14 and 15. By forming the connecting end 50 of the skin layer material 24 into a stepped shape or providing a taper, it is possible to prevent the overall hardness of that portion from increasing. In addition, as shown in FIGS. 15 and 16, if the connecting end 50 is tapered inward or stepped inward, the hard part can be freely deformed. Therefore, the influence of increased hardness can be prevented.

Furthermore, the conductive elastic roller of the present invention is not limited to the embodiments described above, and can be applied to any elastic roller that requires conductivity, such as an antistatic elastic roller.

[Effects of the Invention] As explained above, according to the conductive elastic roller of the present invention, there is no increase in hardness due to conductivity that occurs in conventional single-layer structures, and the conductive elastic roller has a low hardness of, for example, 40 degrees or less. was obtained, and the reliability of the electrical connection between the mandrel and the roller surface was significantly improved.

Further, according to the conductive elastic roller of the present invention, a thermoplastic elastomer mixed with a conductive filler and a thermoplastic elastomer without the addition of a conductive filler are used, and by a sandwich injection molding method,
A conductive elastic roller having a three-layer structure consisting of a first conductive layer, a core layer, and a second conductive layer can be formed around a metal mandrel in one step. Since the electrical connection portions are integrally molded from the same material, there is no electrical connection failure, and conductive elastic rollers with low hardness, for example, 40 degrees or less, can be manufactured in large quantities.

[Brief explanation of drawings]

FIG. 1 is a perspective view of Embodiment 1 of the conductive elastic roller according to the present invention, FIG. 2 is a sectional view of a split mold for manufacturing the conductive elastic roller shown in FIG. 1, and FIGS. 3a, b, c and d are diagrams for explaining the molding process, and are views taken along the line A-A in FIG. 2. Figure 4 a, b
4 shows the molding state using the split mold in Fig. 2, a is a cross-sectional view seen from the same direction as Fig. 2, b is a view taken along the line B-B in a, and Fig. 4 c is a cross-sectional view taken along the line C-C in b. d is a longitudinal sectional view of c, FIG. 5 is a modification of Embodiment 1, a is a longitudinal sectional view, and b is a longitudinal sectional view of the roller.
6 is a perspective view of the conductive elastic roller of Example 2, FIG. 7a is a sectional view of a split mold for manufacturing the conductive elastic roller shown in FIG. 6, and b 8 is a sectional view taken along the line AA of FIG. 7, FIG. 10 is a sectional view taken along line A-A of FIG. 9a, FIG. 11a is a sectional view of the formed roller, and b is a cross-sectional view taken along line A-A of FIG. Figure, 12th
Figure a is a cross-sectional view of the conductive elastic roller of Example 3, and b
is a sectional view taken along the line A-A, FIG. 13 is a sectional view of the split mold for molding of Example 3, FIG.
5, FIG. 16, and FIG. 17 are partial sectional views of other embodiments of the conductive elastic roller, and FIGS. 18 and 19 are views showing conventional conductive elastic rollers. DESCRIPTION OF SYMBOLS 1... Mandrel, 10... First conductive skin layer, 11...
Second core layer, 12...Second conductive skin layer, 13
...Connection wall, 20, 21, 30, 31, 40, 4
1... split mold, 22, 36... cavity, 23,
39... Runner, 24... Skin layer material, 25... Core layer material, 32, 33... Upper support, 34, 35...
Lower fixing groove, 37, 38...Resin flow path.

Claims (1)

[Claims] 1. Consisting of a thin first conductive layer made by adding a conductive filler to a thermoplastic elastomer fixed around a core metal, and a thermoplastic elastomer formed around the first conductive layer. A thick non-conductive core layer, a thin second conductive layer formed around the core layer and formed by adding a conductive filler to a thermoplastic elastomer, the first conductive layer and the second conductive layer. It is characterized by comprising one or more thin-walled connecting walls made of a thermoplastic elastomer to which a conductive filler is added, formed integrally with both conductive layers along the length thereof, between the two conductive layers. Conductive elastic roller. 2. A thin first conductive layer formed by adding a conductive filler to a thermoplastic elastomer fixed around a core, and a thick non-conductive layer made of a thermoplastic elastomer formed around the first conductive layer. and a thin second conductive layer formed around the core layer by adding a conductive filler to a thermoplastic elastomer, one end of the first conductive layer and the second conductive layer. A conductive elastic roller characterized by connecting parts. 3 The skin layer material is a thermoplastic elastomer with a conductive filler added, the core layer material is a thermoplastic elastomer without the addition of a conductive filler, and sand german injection is performed using a mold in which the mandrel is previously supported in a predetermined position. After injecting the skin layer material by a molding method, the core layer material is injected, and the flowing resin part in which the core layer material is wrapped by the skin layer material is poured from one direction or multiple directions along the periphery of the mandrel. a thin first conductive layer surrounding the mandrel by a skin layer material; a thick non-conductive core layer surrounding the first conductive layer by a core layer material; A thin second conductive layer is formed around the core layer by the skin layer material, and a thin second conductive layer is formed between the first conductive layer and the second conductive layer along the length thereof by the skin layer material. A method for manufacturing a conductive elastic roller, characterized in that a roller having a three-layer structure consisting of one or more thin connecting walls connecting conductive layers is molded in one step. 4 The skin layer material is a thermoplastic elastomer with a conductive filler added, the core layer material is a thermoplastic elastomer without the addition of a conductive filler, and sand german injection is performed using a mold in which the mandrel is previously supported in a predetermined position. After the skin layer material is injected by a molding method, the core layer material is injected, and a package of fluid resin in which the core layer material is wrapped by the skin layer material is placed along the axial direction from one end side of the mandrel. The skin layer material forms a thin first conductive layer around the mandrel, and the core layer material forms a thin first conductive layer around the mandrel.
a thick non-conductive core layer surrounding the conductive layer; a thin second conductive layer surrounding the core layer by a skin layer material; A conductive elastic roller having a three-layer structure formed of a conductive layer and a connecting end connecting the other end so as to cover the other end surface of the core layer is molded in one step. manufacturing method.