JP2002347040A - Rubber roller molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a rubber roller having a smooth surface by vulcanizing a rubber layer by quantity of heat reduced than before by making the heat capacity of a cylindrical control member low not only to achieve the shortening of a mold tact and an increase in the efficiency of heat energy at the time of molding but also to suppress the exposure of a filler. SOLUTION: The rubber roller molding method consists of a process for forming the outermost layer comprising a rubber composition on a roller substrate in an unvulcanized state, a process for inserting the roller substrate into the cylindrical control member low in heat capacity and a process for simultaneously performing the vulcanization of the unvulcanized rubber layer on the roller substrate by the heating from the outside and the transfer of the fine uneven shape of the inner surface of the cylindrical control member to the surface of the outermost rubber layer by the utilization of the difference between the coefficient of thermal expansion of the roller substrate and that of the cylindrical control member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method suitable for a rubber roller used in an electrophotographic apparatus such as a copying machine or a printer, or an electrostatic recording apparatus.

[0002]

2. Description of the Related Art Conventionally, a rubber roller used for an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, or the like, in which a rubber layer containing a filler is formed, is often used. As a method of molding these rubber rollers, various molding methods have been devised depending on the type of the base material and the shape of the roller. For example, extrusion molding, injection molding, mold molding, casting molding, and the like are used. .

Among the conventional molding methods such as compression molding, transfer molding and injection molding, there is used a method in which a rubber material is filled into a cavity of a mold without any gap and heated and vulcanized in a pressurized state. In such a molding method, a metal split mold having a thickness sufficient to withstand high pressure and a high strength is often used, and a desired roller shape or dimensional accuracy is obtained after molding the roller. Therefore, the roller surface is polished as needed.

In a molding method using a casting mold composed of a cylindrical mold and lids at both ends, a roller disposed coaxially inside the casting mold. After the rubber material is injected into the cavity formed by the base, the casting mold, and the lids at both ends, a method of heating and vulcanizing under a pressurized state in a similar manner is adopted.
And, in such a molding method, a polishing process can be omitted because a partition line of a mold does not occur as in the above-described compression molding, transfer molding, and the like.
Since the uneven shape of the inner surface of the mold can be transferred to the roller surface, there is an advantage that a roller having good surface properties of the mold can be molded.

Further, as a means for forming a rubber layer as a thin layer as an outermost layer, a rubber material is dissolved in a solvent, and a solution of the rubber coating is formed on a roller substrate.
A rubber roller molding method of forming a rubber layer by open vulcanization in a heating furnace has also been devised.

Further, as a fixing roller used in an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, or the like, a fixing roller in which a fluorine rubber layer as a toner release layer is formed on an outer peripheral surface of a metal roller is used. In recent years, an elastic layer is formed on a metal roller and a fluororubber layer is formed on the outer peripheral surface thereof as a toner release layer.

[0007]

However, in the conventional rubber roller molding methods such as compression molding, transfer molding and injection molding described above, in order to obtain a desired roller outer dimension and shape or a desired roller surface property. However, a polishing step such as grinding the outer peripheral surface of the roller after molding is indispensable, and the surface finish of the roller is naturally limited. In particular, when the outermost layer is made of a rubber material in which at least one or more fillers are dispersed, the filler dispersed in the rubber layer is exposed on the roller surface, thereby impairing the smoothness of the roller surface. It was difficult to obtain a rubber roller having good surface properties. Similarly, conventional rubber roller molding methods such as compression molding, transfer molding, and injection molding are used because a rubber material is filled in a closed system without any gap and heated and vulcanized in a pressurized state. Must have sufficient strength to withstand the high pressures of filling the cavity with material. However, although these molds have high strength, they themselves have large heat capacity, so large heat energy is required for heating the mold itself, and the heat energy cannot be efficiently supplied to the rubber material, resulting in poor heat energy efficiency. There were disadvantages.

[0008] Also, in the method of casting using a mold comprising a thick cylindrical mold and a lid, a partition line of the mold occurs as seen in molding methods such as compression molding and transfer molding. Without this, the surface of the inner surface of the mold can be transferred to the roller surface, so there is an advantage that a roller having good surface properties can be molded without polishing, but for example, several tens to several hundreds μm. When a thin rubber layer is formed on the outermost layer of the roller, the rubber material does not wrap around the entire roller and is not sufficiently filled on the entire surface of the roller. In some cases, the dimensional accuracy of the mold deteriorates, and the heat capacity of the casting mold itself is large, as in the above-mentioned molding method. Energy saving in vulcanization process requires ghee, shortening of molding tact were those bad difficult molding efficiency.

Further, in a fixing roller used in an electrophotographic apparatus such as a copying machine or a printer, an electrostatic recording apparatus, or the like, in order to improve the quality of a copied image, flexibility is imparted to the fixing roller, and The contact area between the toner and the fixing roller is increased to improve the fixability of the toner to the copy paper. As such a fixing roller, for example, a roller in which a relatively low-level silicone rubber layer is formed as an elastic layer is used, and for example, a filler or the like which imparts abrasion resistance is dispersed on the outer peripheral surface of the silicone rubber layer. The outermost layer made of the fluorinated rubber material is used. When the outermost layer is formed of a material having high hardness such as a fluoro rubber layer, it is desired that the outermost layer be formed as a thin film in order to improve the flexibility of the entire roller. In addition, since a heater is arranged on the metal core and the toner is heated and pressed by the heat, it is desired to form the outermost rubber layer in a thin film from the viewpoint of thermal conductivity from the metal core to the fixing roller surface. ing. As a means for forming the outermost rubber layer as a thin layer on the elastic roller as described above, a rubber material is dissolved in a solvent, and this solutionized rubber coating solution layer is formed as a thin layer on the roller base. Then, a method of forming a rubber layer by evaporating the solvent and heating and vulcanizing in an oven has been devised.

However, even when the outermost rubber layer is formed into a thin film having a thickness of, for example, 30 μm or less, the filler dispersed in the outermost rubber layer is exposed to the surface of the fixing roller. However, there is a problem that the smoothness of the surface of the fixing roller is impaired, and as a result, the obtained copy image quality is deteriorated. To solve this problem, Japanese Unexamined Patent Publication No.
Japanese Patent No. 2788 discloses a means for adding a pre-process of reducing the filler component in rubber to an average particle size of 1 μm or less in the process of forming the outermost rubber layer. However, in this method, a step of making the filler in the outermost rubber layer finer is indispensable, and the molding efficiency is deteriorated because the number of steps is increased, and the filler having a large particle diameter is contained in the rubber layer. It was not the best solution due to the inability to do things.

Further, after uniformly coating a rubber material containing at least one or more fillers in solution on a roller base, the solvent is sufficiently volatilized, and the rubber roller having an unvulcanized rubber layer is formed as described above. The outermost rubber layer is inserted into a metal mold with a large thickness, and then the entire rubber layer is heated by utilizing the difference in the coefficient of thermal expansion between the rubber layer and the cylindrical mold. In the method of heating and vulcanizing while pressurizing the inner surface of the mold, as described above, mold partition lines etc. do not occur on the roller surface, and the uneven shape of the mold inner surface can be transferred to the roller surface Although there is an advantage that a roller with good surface properties can be molded without polishing processing, a large amount of heat is required for heating because the cylindrical mold itself has a large heat capacity as in the above molding method And calorie Heat energy efficiency can not be given to efficiently rubber material there has been a disadvantage in that bad.

[0012]

The method of molding a rubber roller according to the present invention takes account of these problems, and the first invention according to the present application for achieving the above object has at least one aspect.
In a method for molding a rubber roller in which a rubber layer comprising a rubber composition containing at least one type of filler is formed on the outermost layer of a roller substrate, the outermost layer comprising the rubber composition is formed on the roller substrate in an unvulcanized state. A step of inserting the roller into a cylindrical regulating member having a low heat capacity; a step of heating and vulcanizing an unvulcanized rubber layer on the roller substrate by heating from the outside; The method is characterized in that a step of simultaneously transferring the minute uneven shape of the inner surface of the cylindrical regulating member to the outermost rubber layer surface by utilizing the difference in the coefficient of thermal expansion with the regulating member is adopted.

That is, the inventors of the present invention have proposed a method of molding a rubber roller in which the outermost layer is made of a rubber composition containing at least one or more fillers, and vulcanizing the unvulcanized rubber layer formed on the roller base in a cylindrical shape. Filled by inserting the inside of the regulating member and transferring the minute irregularities of the inner surface of the cylindrical regulating member to the outermost rubber layer surface using the difference in the coefficient of thermal expansion between the roller base and the cylindrical regulating member It is possible to form a rubber roller with a smooth surface without preventing the agent from being exposed on the roller surface and impairing the smoothness of the rubber roller surface. With a low heat capacity, the conventional method has a large heat capacity and takes a long time to raise the temperature, which requires less heat energy. And a have heat is obtained by allowing the molding in a short time. That is, the improvement of the surface properties of the roller and the improvement of the molding efficiency are simultaneously achieved.

A second invention according to the present application for achieving the above object relates to a case where at least the roller base is an elastic roller coated with one or more elastic layers, and takes into consideration the following problems. is there. For example, in a fixing roller that heats and fixes toner on an unfixed image onto transfer paper, flexibility is imparted to the roller in order to improve the fixability of the toner to the copy paper. As the roller base of the fixing roller, for example, an elastic layer in which a relatively low-level silicone rubber layer or the like is formed is used, and a filler such as a fluororesin which imparts abrasion resistance to the outer peripheral surface of the silicone rubber layer is used. Is used in which an outermost layer made of a fluororubber material in which is dispersed is formed. When the outermost layer is formed of a high-hardness material such as a fluorine rubber layer containing such a filler, the flexibility of the entire roller is improved, or the heat transfer from the core metal to the fixing roller surface is performed. It is desired that the outermost layer be formed as a thin film from the viewpoint of improving the performance. However, in the conventional rubber roller molding method, a polishing step such as grinding the outer peripheral surface of the roller after molding is indispensable in order to obtain a desired roller outer dimension and shape, or a desired roller surface property. There is naturally a limit to the surface finish of the filler, especially when the outermost layer is made of a rubber material in which a filler is dispersed, since the filler dispersed in the rubber layer is exposed on the roller surface and the smoothness of the roller surface is impaired. It was difficult to obtain a rubber roller having good surface properties. Further, a rubber material is dissolved in a solvent, a rubber coating solution layer formed into a solution is formed as a thin layer on a roller substrate, and then the solvent is volatilized and the rubber layer is formed by heating and vulcanizing in an oven. Also in the method, the filler similarly affected the roller surface, and it was difficult to obtain a roller having good surface properties. In addition, a method of dissolving a rubber material in a solvent, forming a thin layer of the rubber coating solution layer formed on a roller substrate into a cylindrical mold, and heating and vulcanizing the roller surface is a method of heating and vulcanizing. Although there is a merit that the unevenness pattern on the inner surface of the cylindrical mold can be transferred to the mold and good surface properties can be obtained, the amount of heat taken away by the mold itself is large and it takes time to cure the rubber layer and a large amount of heat energy is required for heating. Because of the necessity, the heat energy efficiency was low as in the conventional means such as compression molding, transfer molding and injection molding.

The second invention according to the present invention addresses these problems, wherein the roller base is an elastic roller, and the outermost layer is a rubber layer comprising a rubber composition containing at least one or more fillers. Forming a rubber composition containing at least one or more fillers on a roller base in an unvulcanized state, and inserting the roller into a cylindrical regulating member having a low heat capacity. Process, heating and vulcanizing the unvulcanized rubber layer on the roller substrate by heating from the outside, and utilizing the difference in the coefficient of thermal expansion between the roller substrate and the cylindrical regulating member to make the outermost rubber layer surface Even if a rubber composition containing at least one or more fillers is formed in a thin layer on an elastic roller, a step of simultaneously transferring the minute uneven shape of the inner surface of the cylindrical regulating member to the rubber is performed. Dispersed in layers Filler to allow a small amount of heat than the conventional rubber roller having a good surface property without affecting the roller surface, that obtained with less heating time,
The improvement of the surface properties of the roller and the improvement of the molding efficiency are simultaneously achieved.

A third invention according to the present application for achieving the above object is characterized in that the rubber material is heated from outside the cylindrical regulating member using an infrared heater as a heating means. This has the effect that the outermost rubber layer can be heated more efficiently, the heat energy can be more effectively utilized as compared with oven vulcanization, and a significant improvement in heating efficiency and energy saving have been achieved.

A fourth invention according to the present invention for achieving the above object is characterized in that the cylindrical regulating member transmits at least 50% of infrared rays. By using the present invention, the energy of the cylindrical regulating member does not become too warm and its energy reaches the outermost unvulcanized rubber layer and the thermal expansion of the cylindrical regulating member is reduced, so that the rubber layer can be vulcanized with less energy. Can do it.

Further, a fifth invention according to the present application for achieving the above object is characterized in that infrared absorption is equal to or less than a cylindrical regulating member ≦ unvulcanized rubber layer. By using the means of the present invention, the surface of the rubber layer can be directly heated, and the rubber layer can be more efficiently heated and vulcanized.

Further, a sixth invention according to the present application for achieving the above object is characterized in that a polyimide thin tube is used as a surface transfer member. This is because the polyimide material is excellent in heat resistance and strength at high temperatures, can be used repeatedly, improves the durability of the surface transfer member, and has an advantage that it is easy to handle.

[0020]

Next, the present invention will be described in more detail.

As the above-mentioned roller base, a metal core made of a solid metal, a metal cylinder hollowed inside, and an elastic roller having at least one or more elastic layers formed thereon are used. Is done. The rubber material forming the elastic layer of the elastic roller is not particularly limited, and a conventionally known rubber material may be used. For example, the rubber roller obtained by the molding method of the present invention may be used in a heat fixing device such as an LBP or a copying machine. When used as a fixing roller to be used, heat-resistant rubbers such as silicone rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, and fluorosilicone rubber are used, and more preferably, silicone rubber is used.

The rubber material formed on the outermost layer of the roller base is not particularly limited, and any rubber material that can be heated and vulcanized can be used. For example, similarly to the rubber material forming the elastic layer, conventionally known rubber materials such as silicone rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, and fluorosilicone rubber may be used.
When used as a fixing roller for a heat fixing device such as a copying machine, a fluororubber having excellent heat resistance, toner release property and wear resistance is used.

The filler compounded in the rubber layer is appropriately compounded for each purpose. For example, typical reinforcing fillers such as carbon black and white carbon, and other fillers such as carbonic acid Calcium, magnesium carbonate, talc, clay, alumina, mica,
Inorganic fillers such as alumina sulfate, barium sulfate, graphite, silicon carbide, magnesium oxide and fluororesin are used. For example, the roller is a fixing roller used in a heat fixing device such as an LBP or a copying machine,
When the purpose is to improve the abrasion resistance of the outermost rubber layer, an outermost rubber layer in which an appropriate amount of a fluororesin is blended is used.

Further, the low heat capacity cylindrical surface transfer member has an inner diameter capable of inserting a rubber roller having an unvulcanized rubber layer formed on the outer peripheral surface thereof, and has an arbitrary surface roughness on the inner surface. The material may be any material that can withstand the required temperature at the time of vulcanization of the unvulcanized rubber layer, such as a thin metal material such as iron, SUS, or aluminum, or a heat-resistant material such as polyimide or polyphenylene sulfide. Is preferred. Preferably, a thin layer tube of polyimide is used as the cylindrical regulating member. This is because the polyimide thin-layer tube is excellent in heat resistance and high-temperature strength, so that it can be used repeatedly, and the durability of the cylindrical regulating member is improved, so that it is easy to handle.

As a means for forming the solution rubber material on the roller substrate, a conventionally known dipping method,
A roll coating method, a spray coating method, or the like can be used, and the solvent after coating the solution is volatilized at room temperature for a predetermined time to completely volatilize the solvent. Further, the vulcanization temperature of the rubber layer in the step of vulcanizing while pressing the rubber roller having the unvulcanized rubber layer formed between the roller base and the cylindrical regulating member is a temperature at which the rubber layer can be vulcanized. There is no particular limitation, and a known method such as an oven or a hot blast stove can be used as a heating means for vulcanizing the composition.

More preferably, an infrared heater is used as the heating means, in order to increase the heating efficiency in the heat vulcanization step of the unvulcanized rubber layer, and to vulcanize the rubber layer efficiently with less energy. It is.

Further, the cylindrical regulating member reduces the infrared rays by 50%.
Assuming that the infrared absorption is cylindrical control member ≤ unvulcanized peroxide vulcanized rubber layer, the energy of the cylindrical control member reaches the outermost unvulcanized rubber layer without being heated too much. Since the thermal expansion of the cylindrical regulating member is reduced, the rubber layer can be efficiently vulcanized with less energy.

Hereinafter, several embodiments of the present invention will be described.
The present invention will be more specifically described.

(First Embodiment) First, an aluminum alloy having an outer diameter of 58 mm, an inner diameter of 38 mm, and a length of 400 mm (A
5056) A core metal is used as a roller base, and a primer for fluoro rubber (Yokohama Polymer Co., Ltd., V-
16) was applied and heated and dried at a temperature of 150 ° C. for 30 minutes.

Next, a fluororubber material (G501, Daikin Industries, Ltd.) is dissolved in a mixed solvent (2: 8) of methyl ethyl ketone (MEK) and methyl isobutyl ethyl ketone (MIBK). Vulcanizing agent (Daikin Industries, Ltd., V-3) 3
Parts, magnesium oxide (Kyowa Chemical Industry Co., Ltd., Kyowa Mag 30) 15 parts, MT carbon black (Canc
arib Ltd, Thermax N-990) 20
Part, fluororesin (Daikin Industries, Ltd., Lubron L5
F) 20 parts of each were blended to prepare a fluororubber coating solution having a solid content of 25%.

Next, the coating liquid is applied to the roller base by dipping, and air-dried to completely volatilize the solvent, whereby a lmm-thick unvulcanized fluororubber composition is formed on the roller base. A rubber layer was formed.

Next, the roller (FIG. 1) on which the unvulcanized fluororubber layer is formed is inserted into a cylindrical regulating member (FIG. 2) made of a polyimide film, and a roller base and a cylindrical regulating member are inserted. Were fixed and integrated so that the center lines of them were coincident. At this time, the inner diameter of the cylindrical regulating member made of a polyimide film is 60.1 mm, the wall thickness is 0.05 mm, the surface roughness of the inner surface is 5 μm in ten-point average roughness (Rz), Approximately 50
There was a gap of μm. Next, this was put into an oven set to a temperature of 160 ° C. and heated to vulcanize the fluororubber layer. At this time, the unvulcanized fluoro rubber layer was expanded by heat, and was pressed against the inner surface of the cylindrical regulating member made of a polyimide film due to the difference in the coefficient of thermal expansion with the cylindrical regulating member made of a polyimide film, and was pressed. Since vulcanization is performed in this state, the pattern on the inner surface of the cylindrical regulating member is transferred to the surface of the fluororubber layer simultaneously with vulcanization.
Then it is heated in an oven at 200 ° C for 24 hours,
Secondary vulcanization was performed.

The surface roughness of the fluororubber layer formed on the outermost layer of the fluororubber roller (FIG. 3) obtained in this manner has a ten-point average roughness (Rz) of 5 μm and a cylindrical shape. It was confirmed that the inner surface of the member was transferred to the surface of the fluoro rubber roller. At this time, it took about 20 minutes for the fluororubber layer to completely cure.

(Second Embodiment) First, an aluminum alloy having an outer diameter of 53 mm, an inner diameter of 33 mm, and a length of 400 mm (A
5056) HTV type silicone rubber (manufactured by Dow Corning Toray Silicone Co., Ltd .: DY3)
An elastic layer having a thickness of 3.4 mm is formed using 2-903U), and a primer for fluororubber (Yokohama Kogyo Co., Ltd., V-16) is applied thereon and heated at a temperature of 150 ° C. for 30 minutes. The dried product was prepared as a roller substrate.

Next, the same fluororubber coating solution as in Example 1 was prepared, and then the coating solution was applied on a roller substrate by dipping, and air-dried to completely evaporate the solvent. About 50μm
To form a rubber layer made of an unvulcanized fluororubber composition having a thickness of 5 mm.

Next, the roller on which the unvulcanized fluororubber layer is formed is inserted into the same cylindrical regulating member made of a polyimide film as in Example 1, and the roller base and the center of the cylindrical regulating member are inserted. They were fixed and integrated so that the lines matched. At this time, the inner diameter of the cylindrical regulating member made of a polyimide film is 60.1 mm, the wall thickness is 0.05 mm, the surface roughness of the inner surface is 5 μm in ten-point average roughness (Rz), Approximately 50
There was a gap of μm. Next, this was put into an oven set at a temperature of 160 ° C. and heated to cure the unvulcanized fluororubber layer. At this time, the silicone rubber layer, which is an elastic layer, and the unvulcanized fluororubber layer expand by heat, and the unvulcanized fluororubber layer is a cylinder due to the difference in thermal expansion coefficient with the cylindrical regulating member made of a polyimide film. Since the vulcanization is performed while being pressed against the inner surface of the shape regulating member, the pattern on the inner surface of the cylindrical regulating member is transferred to the surface of the fluororubber layer simultaneously with the vulcanization. Thereafter, this was heated in an oven at 200 ° C. for 24 hours to perform secondary vulcanization.

The surface roughness of the fluororubber layer formed on the outermost layer of the fluororubber roller (FIG. 4) obtained in this manner has a ten-point average roughness (Rz) of 5 μm and a cylindrical regulation. It was confirmed that the inner surface of the member was transferred to the surface of the fluoro rubber roller. At this time, it took about 20 minutes for the fluororubber layer to completely cure.

(Third Embodiment) In the same manner as in the second embodiment, the outer peripheral portion of an aluminum alloy (A5056) core bar having an outer diameter of 53 mm, an inner diameter of 33 mm, and a length of 400 mm is provided on an outer peripheral portion of an HTV type silicone rubber (Toray Industries, Ltd.). Dow Corning Silicone Co., Ltd .: DY32-903U) 3.4 m thick
m, and a primer for peroxide-cured fluororubber (Yokohama Polymer Co., Ltd., V-1)
6) was applied and heated and dried at a temperature of 150 ° C. for 30 minutes to prepare a roller base.

Next, the same fluororubber coating solution as in Example 1 was prepared, and then the coating solution was applied on a roller substrate by dipping, and air-dried to completely evaporate the solvent. About 50μm
To form a rubber layer made of an unvulcanized fluororubber composition having a thickness of 5 mm.

Next, the roller on which the unvulcanized fluororubber layer was formed was inserted into the same cylindrical regulating member made of a polyimide film as in Example 1, and the roller base and the center of the cylindrical regulating member were inserted. They were fixed and integrated so that the lines matched. At this time, the inner diameter of the cylindrical regulating member made of a polyimide film is 60.1 mm, the wall thickness is 0.05 mm, the surface roughness of the inner surface is 5 μm in ten-point average roughness (Rz), Approximately 50
There was a gap of μm.

Next, the roller base and the surface transfer member integrated as described above were heated from outside the cylindrical regulating member by an infrared heater. In this embodiment, the length (3
An infrared line heater (parallel light type) having a power of 3 kW and having a width of 00 mm (parallel light type) was disposed at a distance of about 50 mm from the surface of the cylindrical regulating member, and heating was performed. At this time, the elastic silicone rubber layer and the unvulcanized fluoro rubber layer expand by heat, and are pressed against the inner surface of the cylindrical regulating member made of a polyimide film, and vulcanization is performed in a pressurized state. At the same time, the pattern on the inner surface of the cylindrical regulating member is transferred. Heating the unvulcanized fluororubber layer more efficiently and in a shorter time than by heating in an oven by heating from the outside using an infrared line heater as a means of heating the fluororubber layer. Was completed. Thereafter, the resultant was cooled, and the polyimide film was removed from the roller base to obtain a fluoro rubber roller. Then, this was further heated in an oven at 200 ° C. for 24 hours to perform secondary vulcanization. In this embodiment, it took about 6 minutes for the fluororubber layer to be completely vulcanized.

The surface of the fluororubber roller thus obtained has a ten-point average roughness (Rz) of 5 μm.
It was confirmed that the surface pattern of the cylindrical regulating member was transferred to the surface of the fluoro rubber roller. In addition, the vulcanization time of the fluororubber layer can be significantly reduced compared to heating in an oven (about 20 minutes), and the molding efficiency can be increased and energy saving can be achieved.

(Comparative Example 1) Outer diameter: 59 mm, inner diameter 39 m
m, length: 400 mm aluminum alloy (A505
6) Apply a fluoro rubber primer (V-16, Yokohama Polymer Co., Ltd.) to the outer periphery of the core metal, and apply the primer at 150 ° C.
What was heated and dried for 0 minutes was prepared as a roller base.

Next, 3 parts of a vulcanizing agent (V-3, Daikin Industries, Ltd.) and 15 parts of magnesium oxide (Kyowa Kagaku Kogyo, Kyowa Mag 30) were added to 100 parts by weight of a fluoro rubber material (G501, Daikin Industries, Ltd.). Part, MT carbon black (Cancarib Ltd, Therm
axN-990) and 20 parts of a fluororesin (Daikin Industries, Ltd., Lubron L5F) were prepared.

Next, the roller base was previously heated to 160 ° C.
After being placed inside a transfer molding die having an inner diameter of 61 mm, which has been preheated to a temperature of 60 ° C., the above-mentioned fluororubber composition is poured into a cavity of the die, and heated at a temperature of 160 ° C. to form a roller. A fluororubber layer having a thickness of 1 mm was formed on the outer periphery of the substrate. At this time, a heating time of 20 minutes was required until the fluororubber layer was completely vulcanized. Then, after taking out from a metal mold and performing secondary vulcanization at a temperature of 200 ° C. for 24 hours, the roller surface was ground to have an outer diameter of 60 m.
m of a fluoro rubber roller was obtained.

The surface roughness of the fluororubber roller thus obtained was 15 μm in ten-point average roughness (Rz), and the surface property was not good. Improvement was difficult. This may be because the filler contained in the outermost rubber layer is exposed by polishing the roller surface. Also, a large amount of heat is required during preheating and heat vulcanization of the transfer molding die, and the heat energy efficiency is lower than that of the oven vulcanization using a cylindrical regulating member and the heating method using infrared heating. Was.

(Comparative Example 2) Outer diameter:
A thickness of 3.4 mm made of an HTV type silicone rubber (manufactured by Dow Corning Toray Silicone Co., Ltd .: DY32-903U) is provided on the outer periphery of a core made of an aluminum alloy (A5056) having a diameter of 53 mm, an inner diameter of 33 mm, and a length of 400 mm.
An elastic layer is formed, and a primer for peroxide-cured fluororubber is formed thereon (Yokohama Polymer Co., Ltd., V-16)
Was dried at a temperature of 150 ° C. for 30 minutes to prepare a roller base.

Next, the same fluororubber coating solution as in Example 1 was prepared, and then this coating solution was applied on a roller substrate by dipping, and air-dried to completely evaporate the solvent. About 50μm
To form a rubber layer made of an unvulcanized fluororubber composition having a thickness of 5 mm.

Next, the roller on which the unvulcanized fluororubber layer was formed was put into an oven set at 160 ° C. and heated and vulcanized. Then, it was heated in an oven at 200 ° C. for 24 hours to perform secondary vulcanization.

At this time, it took about 20 minutes for the fluororubber layer to be completely vulcanized. The surface roughness of the fluororubber roller thus obtained was 10 μm in ten-point average roughness (Rz), and the surface property was not good. This is because the filler compounded in the fluororubber material is exposed to the roller surface by forming the outermost layer as a thin layer, and if there is no regulating member, this surface state is vulcanized as it is and remains. Conceivable.

(Comparative Example 3) Outer diameter:
A thickness of 3.4 mm made of an HTV type silicone rubber (manufactured by Dow Corning Toray Silicone Co., Ltd .: DY32-903U) is provided on the outer periphery of a core made of an aluminum alloy (A5056) having a diameter of 53 mm, an inner diameter of 33 mm, and a length of 400 mm.
An elastic layer is formed, and a primer for peroxide-cured fluororubber is formed thereon (Yokohama Polymer Co., Ltd., V-16)
Was dried at a temperature of 150 ° C. for 30 minutes to prepare a roller base.

Next, the same fluororubber coating solution as in Example 1 was prepared, and then this coating solution was applied on a roller substrate by dipping, and air-dried to completely volatilize the solvent. About 50μm
To form a rubber layer made of an unvulcanized fluororubber composition having a thickness of 5 mm.

Next, the above-mentioned roller on which the unvulcanized fluororubber layer is formed has a thickness of 5 mm and an inner surface having a surface roughness of 5 μm.
m, and was fixed and integrated by lids at both ends such that the center line of the roller base and the cylindrical mold matched each other. At this time, there was a gap of about 50 μm between the roller base and the cylindrical mold. Then add this to 160
The unvulcanized fluororubber layer was vulcanized by heating in an oven set to a temperature of ° C and heating. At this time, the silicone rubber layer and the unvulcanized fluororubber layer which are elastic layers are expanded by heat, and the unvulcanized fluororubber layer is formed of the cylindrical mold from the difference in thermal expansion coefficient with the cylindrical mold. Since the vulcanization is performed while being pressed against the inner surface and pressed, the pattern of the inner surface of the cylindrical mold is transferred to the surface of the fluororubber layer simultaneously with the vulcanization. Thereafter, the roller was removed from the cylindrical mold to obtain a rubber roller having a fluorine rubber formed on the outermost layer. Next, it was heated in an oven at 200 ° C. for 24 hours to perform secondary vulcanization.

The surface roughness of the fluororubber layer formed on the outermost layer of the thus obtained fluororubber roller is such that the ten-point average roughness (Rz) is 5 μm and the inner surface of the cylindrical mold is It was confirmed that the image was transferred to the surface of the fluoro rubber roller. However, since the cylindrical mold has a large heat capacity, a large amount of heat is required for heating, and a time is required for raising the temperature, so that the molding efficiency is poor.

Table 1 shows the time required for vulcanizing the rubber layers of the fluororubber rollers obtained in Examples 1 to 3 and Comparative Examples 1 to 3, and the surface roughness of each roller.

[0056]

[Table 1]

As is apparent from the results shown in Table 1, in the method of molding a rubber roller according to the present invention, in the means for molding a rubber roller whose outermost layer is made of a rubber composition containing at least one or more fillers, the filler has a roller surface. It is possible to mold a rubber roller having a smooth surface without impairing the smoothness of the rubber roller surface, and at the same time, to reduce the cylindrical regulating member during heating and vulcanization with a low heat capacity. By doing so, molding can be performed in a short time with a smaller amount of heat than in the past, and an increase in molding efficiency has been achieved. For example, in Comparative Example 1, there is a limit in improving the surface properties because polishing is indispensable.
In, the surface is not regulated, so that the exposed filler remains on the surface as it is. Further, in Comparative Example 3, since the regulating member was a conventional thick metal cylindrical mold, a large amount of heat and a long time were required during heating, resulting in poor molding efficiency. The molding method of the present invention shows that the outermost layer can be efficiently molded in a good condition of the surface properties of the roller in the means for molding a rubber roller comprising a rubber composition containing at least one or more fillers. I have.

[0058]

As described above, the method of molding a rubber roller of the present invention relates to a method of molding a rubber roller in which a rubber layer comprising a rubber composition containing at least one or more fillers is formed on the outermost layer of a roller base. Forming the outermost layer of the rubber composition on a roller base in an unvulcanized state, inserting the roller into a cylindrical regulating member having a low heat capacity, and heating the roller by applying heat from outside. By heating and vulcanizing the unvulcanized rubber layer on the base and utilizing the difference in the coefficient of thermal expansion between the roller base and the cylindrical restricting member, the fine irregularities on the inner surface of the cylindrical restricting member are formed on the outermost rubber layer surface. It is characterized by taking the process of simultaneously transferring and transferring.
This prevents the filler from being exposed on the roller surface and enables the molding of a rubber roller with a smooth surface without impairing the smoothness of the rubber roller surface. By making the member of low heat capacity, it takes less time to raise the temperature due to the large heat capacity of the conventional method, and it requires less heat energy than the method of molding a rubber roller using a thick mold that required large heat energy during heating And enables molding in a short time. That is, the improvement of the surface properties of the roller and the improvement of the molding efficiency are simultaneously achieved.

Further, an infrared heater is used as the heating means, the cylindrical regulating member is made of a material which transmits infrared rays by 50% or more, and the absorption of infrared rays is less than the cylindrical regulating member.
By using an unvulcanized peroxide vulcanized rubber layer, the rubber layer can be more efficiently heated and vulcanized, thereby achieving further energy saving.

[Brief description of the drawings]

FIG. 1 Elastic roller on which an outermost layer of unvulcanized fluoro rubber is formed

FIG. 2 is a cylindrical regulating member made of polyimide used in the present invention.

FIG. 3 is a cross-sectional view of a single-layer rubber roller molded in the present invention.

FIG. 4 is a cross-sectional view of a multilayer rubber roller molded in the present invention.

[Explanation of symbols]

 Reference Signs List 1 core metal 2 unvulcanized rubber layer 3 cylindrical regulating member 4 outermost rubber layer 5 elastic layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H033 AA21 BB29 BB30 BB31 3J103 AA02 AA14 AA32 AA61 BA41 EA02 EA11 FA15 FA20 GA02 GA57 GA58 HA02 HA04 HA12 HA53 4F203 AA45 AB11 AE10 AH04 AJ03 AM32 DA11 DB01 DC01

Claims (6)

[Claims] 1. A method for molding a rubber roller, wherein a rubber layer comprising a rubber composition containing at least one or more fillers is formed on the outermost layer of a roller substrate, comprising: Forming on the roller, inserting the roller into a low-heat-capacity cylindrical regulating member, heating and vulcanizing the unvulcanized rubber layer on the roller substrate by heating; and Simultaneously transferring the minute irregularities on the inner surface of the cylindrical restricting member to the roller surface by utilizing the difference in the coefficient of thermal expansion of the cylindrical restricting member. 2. The method according to claim 1, wherein the roller base is an elastic roller. 3. The method of molding a rubber roller according to claim 1, wherein an infrared heater is used as a heating means in the method of molding the rubber roller, and heating is performed from outside the cylindrical regulating member. 4. The method for molding a rubber roller according to claim 1, wherein the cylindrical regulating member transmits at least 50% of infrared rays. 5. The method of molding a rubber roller according to claim 1, wherein in the method of molding a rubber roller, absorption of infrared rays is equal to or less than a cylindrical regulating member ≦ unvulcanized rubber layer. . 6. The method of molding a rubber roller according to claim 1, wherein a polyimide tube is used as the cylindrical regulating member in the method of molding a rubber roller.