JPH07214697A - Production of conductive rubber roll - Google Patents

Abstract

PURPOSE:To produce a conductive rubber roll in a short time and arbitrarily alter the thickness or length of a rubber layer by extruding foamed silicone rubber and soft silicone rubber from respectively separate extruders to guide them to a die and simultaneously subjecting two rubber layers to be superposed to extrusion molding to vulcanize them simultaneously. CONSTITUTION:A foamed silicone rubber layer 2 and a soft silicone rubber layer 1 are wound around the core metal P provided to the centers of the extrusion dies 14 of extruders 12, 13. Foamed silicone rubber 2A is injected into the extruder 12 from the gap between the first and second dies 14A, 14B with respect to the core metal P to be fixed to the surface of the core metal P. The thickness of the foamed silicone rubber layer 2 is adjusted by the second die 14B. Next, soft silicone rubber 1A is injected into the extruder 13 from the gap between second and third dies 14B, 14C to be fixed to the surface of the foamed silicone layer 2. The thickness of the soft silicone layer 1 is adjusted by the third die 14C. Next, bath layers are simultaneously vulcanized in a vulcanizing and foaming process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method for producing a conductive rubber roller used as a feed roller, a charging roller, a transfer roller or the like inside a device such as a printer, a copying machine or a fax machine.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a multi-layered roller used as a feed roller, there is a manufacturing method described in JP-A-63-230464. According to this manufacturing method, an organic low-molecular compound containing a conductive material is applied to the inner wall of the mold cavity, and a composition undiluted solution containing a foaming agent is injected by a reaction injection molding method. A roller molded by such a manufacturing method has a cored bar as a central axis and a laminated structure of a foam layer and a semiconductive non-charged layer formed around the cored bar.

On the other hand, as a single-chamber conductive rubber roller used as a charging roller, a transfer roller, etc.
There is a conductive silicone rubber roller described in JP-A 5-116790. In this rubber roller, a silicon rubber layer made of a conductive silicone rubber composition containing carbon black is provided on a roller shaft.

[0004]

However, when the conventional conductive rubber roller is manufactured by the conventional method, the following problems remain.

That is, since the former method for manufacturing a multi-layer roller used as a feed roller is manufactured by using a mold, a mold release agent is previously applied to the inside of this mold and an excess mold release agent is wiped off. Many processes are required for manufacturing, such as wiping with a jig.

Further, since the length of the roller is set by the length of the mold, the size of the roller cannot be freely changed.

Further, the semi-conductive non-charged layer formed on the surface of the roller is formed by spray coating from a nozzle.
Although it is possible to form a thin layer, it is difficult to form a thick non-charged layer. Even if this non-charged layer is formed thick, it is extremely difficult to make the thickness uniform. there were.

On the other hand, in the latter case of a single-layer conductive rubber roller used as a charging roller or a transfer roller, carbon black is blended with the conductive rubber material used for the conductive rubber roller. However, when the conductivity is increased by increasing the blending ratio of the conductive carbon black, the fusion strength at the boundary surface of each layer decreases. Therefore, in order to form a conductive rubber roller containing carbon black into a multilayer structure, first, the conductive rubber is vulcanized and cured by primary vulcanization and secondary vulcanization, and then the cured conductive rubber is vulcanized. After polishing to a predetermined diameter, further, after applying an adhesive to the surface of the conductive rubber and film-coating the conductive agent, a lot of time and steps such as curing the adhesive and the conductive agent again are required. It was such a thing.

Moreover, conventionally, the roller used as a feed roller and the roller used as a charging roller, a transfer roller, etc., have different thicknesses of the conductive layer and dimensions of the roller itself, so that each roller is different. The manufacturing process was different. Therefore, it has been desired to provide a method for manufacturing a conductive rubber roller that can manufacture these conductive rollers on the same line.

Therefore, the present invention was created in order to solve the above-mentioned problems, and can be manufactured in a short time.
In addition, the thickness of the conductive rubber layer and the length of the roller can be changed arbitrarily, making it possible to manufacture conductive rollers with different purposes for use on the same line. It is an object of the present invention to provide a method for producing a conductive rubber roller that can improve the adhesion.

[0011]

In order to achieve the above-mentioned object, the present invention covers a conductive foamed silicone rubber layer wound around the surface of a metal core of a roller shaft and a surface of the foamed silicone rubber layer. Provided is a method for manufacturing a conductive rubber roller including a conductive soft silicone rubber layer.

First, in the extrusion molding step, the foamed silicone rubber and the soft silicone rubber are introduced into extrusion dies by different extrusion machines, and the silicone rubber layers that are polymerized into two layers are simultaneously extrusion-molded.

Next, in the vulcanization and foaming step, the foamed silicone rubber layer and the soft silicone rubber layer are simultaneously vulcanized.

The second means is that the foamed silicone rubber layer and the soft silicone rubber layer are wound around the cored bar inserted in the extruder at the time of extrusion molding.

The third means is an alternative to the second means, and the foamed silicone rubber layer and the soft silicone rubber layer are formed in a hollow cylindrical shape.

The fourth means relates to the components of each layer. The soft silicone rubber layer has a weight ratio of 100% to a conductive polymer containing carbon black.
A vulcanizing agent of bis 1.6 (T-butylperoxine) hexane of 1 to 3 was added, while the foamed silicone rubber layer had a bis ratio of 1 to 3 with respect to the conductive polymer having a weight ratio of 100. 1.6 The addition of a vulcanizing agent of (T-butylperoxine) hexane and a blowing agent of azobisisobutyronitrile in a weight ratio of 2 to 4 is a means for solving the problem.

[0017]

That is, according to the present invention, according to claim 1,
A multi-layered conductive rubber roller composed of a foamed silicone rubber layer and a soft silicone rubber layer is simultaneously extruded and molded.

At this time, according to claim 2, the multi-layered conductive rubber roller is formed integrally with the core metal.

According to the third aspect of the present invention, a hollow tube-shaped conductive rubber roller having a multilayer structure is extruded.

On the other hand, according to claim 4, the vulcanizing agent of bis1.6 (T-butylperoxine) hexane enhances the fusion force between the foamed silicone rubber layer and the soft silicone rubber layer made of a conductive polymer containing carbon black. To do.

[0021]

EXAMPLES The basic structure of a conductive rubber roller mixed with carbon black manufactured by the present invention is as follows: a conductive silicone rubber layer 2 wound around the surface of a core metal P that serves as a roller core shaft; And a conductive soft silicone rubber layer 1 covering the surface of the rubber layer 1 (see FIG. 3 or 6).

In the extrusion molding step 10, the foamed silicone rubber 2A and the soft silicone rubber 1A are introduced into the extrusion die 14 by different extrusion machines 12 and 13, respectively, and a silicone rubber layer which is polymerized into two layers is simultaneously extrusion-molded. Yes (see FIGS. 2 and 5).

The extrusion die 14 shown in FIG. 2 uses a three-piece extrusion die 14 to form a silicone rubber layer around the core metal P. That is, a cored bar insertion opening is provided at the center of the extrusion die 14, and the foamed silicone rubber layer 2 and the soft silicone rubber layer 1 are wound around the cored bar P inserted into the cored bar insertion opening. To do. According to this extrusion die 14, the first metal is
The foamed silicone rubber 2A is injected from between the die 14A and the second die 14B and fixed to the surface of the core P. Then, the thickness of the foamed silicone rubber layer 2 is adjusted by the second die 14B. Next, the soft silicone rubber 1A is injected from between the second die 14B and the third die 14C and fixed to the surface of the foamed silicone rubber layer 2. Then, the thickness of the soft silicone rubber layer 1 is adjusted by the third die 14C.

In the extrusion die 14 shown in FIG. 5, a double-layered extrusion die 14 is used to form a multi-layer hollow cylindrical body. That is, the inner diameter adjusting nipple W is attached to the center of the extrusion die 14, and a hollow cylindrical silicone rubber layer is extruded from the gap between the inner diameter adjusting nipple W and the extrusion die 14. According to this extrusion die 14, first, the extrusion die 1
The foamed silicone rubber 2A injected into the No. 4 is the first die 1
The inner diameter and the thickness of the foamed silicone rubber layer 2 are adjusted by 4A and the inner diameter adjusting nipple W. Next, the soft silicone rubber 1A is injected from between the first die 14A and the second die 14B and fixed to the surface of the foamed silicone rubber layer 2. Then, the thickness of the soft silicone rubber layer 1 is adjusted by the second die 14B.

In the vulcanization and foaming step 20, the soft silicone rubber layer 1 and the foamed silicone rubber layer 2 are simultaneously vulcanized (see FIGS. 1 and 4).

The vulcanization and foaming step 20 shown in FIG. 1 uses a hot air vulcanization tank 21 and a secondary vulcanization tank 22. That is,
The roller with the core metal P formed in the extrusion molding step 10 is carried to the hot air vulcanization tank 21 by the horizontal carrier Q. Then, the vulcanization and foaming step 20 is completed through the hot air vulcanization tank 21 and the secondary vulcanization tank 22. After the soft silicone rubber layer 1 and the foamed silicone rubber layer 2 are hardened, the product is made into a predetermined size by the both-ends finishing cutting machine J.

In the vulcanization and foaming step 20 shown in FIG. 4, the vulcanization is performed in the microwave vulcanization tank 23 before vulcanization in the hot air vulcanization tank 21. By doing so, the hollow cylindrical body can be vulcanized more reliably. Further, the hollow cylindrical body is integrally wound by the take-up machine 24 from the extrusion molding process 10 to the take-up machine 25. And the winding machine 25
The hollow cylindrical body wound around is vulcanized in the secondary vulcanization tank 22, and the vulcanization and foaming step 20 is completed. After that, the hollow cylindrical body is cut to an arbitrary size by the standard length cutting machine K, and the core bar P having a predetermined size is inserted by the core bar inserting machine L to obtain a product.

In the soft silicone rubber layer 1, a vulcanizing agent of bis1.6 (T-butylperoxine) hexane having a weight ratio of 1 to 3 is added to a conductive polymer containing carbon black and having a weight ratio of 100. To do.

The foamed silicone rubber layer 2 is a vulcanizing agent of bis1.6 (T-butylperoxine) hexane having a weight ratio of 1 to 3 with respect to a conductive polymer containing carbon black and having a weight ratio of 100. And a blowing agent of azobisisobutyronitrile in a weight ratio of 2 to 4 are used.

[0030]

The present invention achieves the original object by having the above-mentioned configuration.

That is, according to the first aspect, since the silicone rubber layer that is polymerized into two layers is simultaneously extrusion-molded and simultaneously vulcanized, the conductive rubber roller having a multilayer structure can be manufactured in a short time.

Further, according to claim 2 or 3, the thickness of each layer of the conductive layer and the size of the roller itself can be freely set. Therefore, the conductive roller such as the feeding roller, the charging roller, and the transfer roller should be manufactured on the same line. Became possible.

Further, according to claim 4, even in the case of a conductive rubber roller having a multi-layer structure containing carbon black, the soft silicone rubber layer 1 and the foamed silicone rubber layer 2 can be simultaneously vulcanized. The fusion force of each layer can be increased while maintaining the conductivity.

As described above, according to the present invention, it is possible to manufacture in a short time, and the thickness of the conductive rubber layer and the length of the roller can be arbitrarily changed, and the same applies to conductive rollers having different purposes. The present invention has various industrially beneficial effects such that it can be manufactured on-line, and the fusion force of each layer can be increased while maintaining the conductivity.

[Brief description of drawings]

FIG. 1 is a process drawing showing a manufacturing process of the present invention.

FIG. 2 is a cross-sectional view showing an extrusion die used in the extrusion molding process of the present invention.

FIG. 3 is a cross-sectional view of a conductive rubber roller manufactured by the present invention.

FIG. 4 is a process drawing showing another manufacturing process of the present invention.

FIG. 5 is a sectional view showing an extrusion die used in another extrusion molding process of the present invention.

FIG. 6 is a cross-sectional view of another conductive rubber roller manufactured according to the present invention.

[Explanation of symbols]

 P Core bar Q Horizontal transfer machine J Both ends finishing cutting machine K Standard length cutting machine L Core bar inserting machine 1 Soft silicone rubber layer 1A Soft silicone rubber 2 Foam silicone rubber layer 2A Foam silicone rubber 10 Extrusion molding process 11 Core bar inserting machine 12 Extruder 13 Extruder 14 Extrusion die 14A 1st die 14B 2nd die 14C 3rd die 15 Die press 20 Vulcanization foaming process 21 Hot air vulcanization tank 22 Secondary vulcanization tank 23 Microwave vulcanization tank 24 Take-off machine 25 Roll Taker

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Claims (4)

[Claims] 1. A conductive rubber roller comprising a conductive foamed silicone rubber layer wound around the surface of a metal core of a roller shaft core, and a conductive soft silicone rubber layer covering the surface of the foamed silicon rubber layer. In the extrusion molding step, the foaming silicone rubber and the soft silicone rubber are introduced into extrusion dies by different extrusion machines, and a silicone rubber layer which is polymerized into two layers is simultaneously extrusion-molded in the extrusion molding step. A method for producing a conductive rubber roller, which comprises simultaneously vulcanizing the foamed silicone rubber layer and the soft silicone rubber layer in a vulcanization and foaming step. 2. The method for producing a conductive rubber roller according to claim 1, wherein the foamed silicone rubber layer and the soft silicone rubber layer are wound around a cored bar inserted in an extruder during extrusion molding. 3. The method for producing a conductive rubber roller according to claim 1, wherein the foamed silicone rubber layer and the soft silicone rubber layer are formed in a hollow cylindrical shape. 4. The soft silicone rubber layer comprises bis-1.6 (T-butylperoxine) having a weight ratio of 1 to 3 with respect to a conductive polymer containing carbon black and having a weight ratio of 100.
Hexane vulcanizing agent was added, while the foamed silicone rubber layer had a weight ratio of 100 to the conductive polymer.
4. The conductive rubber roller according to claim 1, wherein 1 to 3 vulcanizing agent of bis1.6 (T-butylperoxine) hexane and 2 to 4 weight ratio of azobisisobutyronitrile blowing agent are added. Manufacturing method.