JP2018120041A - Manufacturing method of rubber roller for thermal fixation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress corrosion of a core shaft. SOLUTION: The method for manufacturing a rubber roller for heat fixing of the present invention includes an intermediate layer forming step of forming an intermediate layer on the outer peripheral surface of a core shaft formed of a metal material, and an intermediate layer on the outer peripheral surface of the core shaft. It has a sponge layer forming step of forming a sponge layer. In the sponge layer forming step, the silicone rubber layer containing the water-soluble powder is formed, and then the water-soluble powder is eluted from the silicone rubber layer into water to form the sponge layer. In the intermediate layer forming step, an intermediate layer is formed using silicone rubber. [Selection diagram] Fig. 1

Description

  The present invention relates to a method of manufacturing a heat fixing rubber roller.

  In electrophotographic image forming apparatuses (copiers, laser beam printers, etc.), a heat fixing method is generally employed as a fixing method for fixing toner transferred onto a transfer material (plain paper, plastic film, etc.). Yes. In the thermal fixing method, the toner image is fixed to the transfer material by applying pressure to the toner image melted by heat. In the heat fixing method, a heat fixing rubber roller is used. When the toner image is heat fixed, the roller surface (outer peripheral surface) of the heat fixing rubber roller is transferred to the transfer material onto which the toner image is transferred. Contact with.

  For example, a sponge layer and a release layer are sequentially provided on the outer peripheral surface of a cylindrical core shaft. In the heat fixing rubber roller, the core shaft is made of a metal material such as iron or aluminum. In order to ensure sufficient heat resistance, the sponge layer is formed of, for example, a porous body of silicone rubber. The release layer is made of, for example, a fluororesin so as to have a release property for the toner.

  In order to prevent deterioration of the image quality of the fixed image and change in the transfer speed of the transfer material (plain paper, plastic film, etc.), the heat fixing rubber roller is removed when the temperature rises. There is a demand for little change in diameter and little change in surface hardness. For this reason, in the heat fixing rubber roller, bubbles (holes) are continuously formed in the sponge layer in order to improve air permeability.

  The sponge layer is formed by a forming method such as “(a) a method using a heating type foaming agent”, “(b) a method using a hollow filler”, or “(c) an elution method”.

  In “(a) a method using a heating type foaming agent”, when the rubber is crosslinked, the foaming agent is decomposed to generate gas (bubbles), thereby forming a sponge layer. In this case, the odor of gas generated when the foaming agent is decomposed may be a problem. In addition, when an addition reaction type silicone rubber is cured using a platinum catalyst as a curing catalyst, curing may be insufficient due to the foaming agent.

  In “(b) Method of using hollow filler”, a sponge layer is formed by mixing a hollow filler with rubber. In this case, since the difference between the density of the rubber and the density of the hollow filler is large, the bubbles may be non-uniform in the sponge layer. Moreover, since a hollow filler is used, a manufacturing cost may become high.

  On the other hand, in the “(c) elution method”, after the rubber mixed with the water-soluble powder is cross-linked, the water-soluble powder is eluted into water to form a sponge layer. In this method, unlike the “(a) method using a heating type foaming agent”, since the heating type foaming agent is not used, the problem of odor does not occur. Unlike the “(b) method using a hollow filler”, an inexpensive water-soluble powder is used without using a hollow filler, so that the manufacturing cost can be reduced.

  In “(c) elution method”, various techniques have been proposed in order to improve the performance of the sponge layer. For example, after forming a silicone rubber layer containing triethylene glycol together with water-soluble powder (sugar powder), the water-soluble powder and triethylene glycol are eluted from the silicone rubber layer into water. As a result, in the sponge layer, bubbles are uniformly formed and the open cell rate is increased (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2006-8990

  However, when the sponge layer is formed by the “(c) elution method”, the core shaft may corrode due to the water used in the elution of the water-soluble powder. As a result, depending on the degree of corrosion, the sponge layer may peel off from the core shaft.

  In particular, when the sponge layer is formed by an elution method using triethylene glycol, it may be difficult to sufficiently suppress the core shaft corrosion (generation of rust). Triethylene glycol is highly hygroscopic. For this reason, corrosion of the core shaft may be promoted due to triethylene glycol remaining in the sponge layer.

  Therefore, the problem to be solved by the present invention is to provide a method for manufacturing a heat fixing rubber roller capable of easily suppressing corrosion of the core shaft.

  The manufacturing method of the heat fixing rubber roller of the present invention includes an intermediate layer forming step of forming an intermediate layer on the outer peripheral surface of the core shaft made of a metal material, and a sponge layer formed on the outer peripheral surface of the core shaft via the intermediate layer. And a sponge layer forming step. In the sponge layer forming step, after forming the silicone rubber layer containing the water-soluble powder, the sponge layer is formed by eluting the water-soluble powder from the silicone rubber layer into water. In the intermediate layer forming step, the intermediate layer is formed using silicone rubber.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the rubber roller for heat fixing which can suppress easily corrosion of a core axis | shaft can be provided, maintaining the adhesive strength of a core axis | shaft and a sponge layer.

FIG. 1 is a side view schematically showing a heat fixing rubber roller according to an embodiment. FIG. 2 is a cross-sectional view schematically showing the heat fixing rubber roller according to the embodiment.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. The invention is not limited to the contents of the drawings. Further, the drawings show an outline, and the dimensional ratio of each part does not necessarily match the actual one. In addition, about the same component, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted suitably.

[A] Configuration FIGS. 1 and 2 are views schematically showing a heat fixing rubber roller according to an embodiment. FIG. 1 shows a side surface of the heat fixing rubber roller 1, and the vertical direction is an axial direction z along the rotation axis AX of the heat fixing rubber roller 1. FIG. 2 shows a cross section of the X1-X1 portion in the heat fixing rubber roller 1 shown in FIG. 1, and the direction perpendicular to the paper surface is the axial direction z.

  As shown in FIGS. 1 and 2, the heat fixing rubber roller 1 has a cylindrical outer shape, and includes a core shaft 10, an intermediate layer 20, a sponge layer 30, and a release layer 40. Each part constituting the heat fixing rubber roller 1 will be described in order.

[A-1] Core shaft 10
The core shaft 10 is a cylindrical base material and is formed of a metal material. Here, the core shaft 10 is formed using, for example, iron or aluminum.

[A-2] Intermediate layer 20
The intermediate layer 20 is provided so as to cover the outer peripheral surface of the core shaft 10, and is interposed between the core shaft 10 and the sponge layer 30. In the present embodiment, the intermediate layer 20 is a homogeneous layer formed using silicone rubber and is not a porous layer. Although details will be described later, the intermediate layer 20 functions as a corrosion prevention layer for preventing the core shaft 10 from being corroded. The intermediate layer 20 is formed so that the lower limit of the thickness is 0.1 mm or more in order to sufficiently prevent corrosion of the core shaft 10. The upper limit value of the thickness of the intermediate layer 20 can be arbitrarily set in consideration of factors such as the outer diameter size and performance of the heat fixing rubber roller 1. For example, the upper limit value of the thickness of the intermediate layer 20 is set to 1.5 mm or less.

[A-3] Sponge layer 30
The sponge layer 30 is provided so as to cover the outer peripheral surface of the core shaft 10 through the intermediate layer 20. In the present embodiment, the sponge layer 30 is a porous layer formed using silicone rubber, and includes a large number of bubbles. The thickness of the sponge layer 30 is, for example, in the range of not less than 2.0 mm and not more than 10.0 mm. Although details will be described later, the sponge layer 30 of the present embodiment is formed by an elution method.

[A-4] Release layer 40
The release layer 40 is provided so as to cover the outer peripheral surface of the core shaft 10 via the intermediate layer 20 and the sponge layer 30. The release layer 40 is made of, for example, a release resin such as a fluororesin in order to obtain release properties for the toner. Specifically, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene / tetrafluoroethylene copolymer Fluorine resins such as (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), and polyvinylidene fluoride (PVdF) are suitably used as the release resin. The release layer 40 may be formed using a release resin such as a polyimide resin or a polyamideimide resin in addition to the fluororesin. The thickness of the release layer 40 is, for example, 10 μm or more and 100 μm or less. The release layer 40 may not be provided on the heat fixing rubber roller 1 if unnecessary.

  In the heat fixing rubber roller 1, a primer layer (not shown) may be interposed between the core shaft 10 and the intermediate layer 20.

  The heat fixing rubber roller 1 constitutes a heat fixing portion (not shown) in an electrophotographic image forming apparatus (not shown). The heat fixing unit includes, for example, a pressure roller (not shown) together with the heat fixing rubber roller 1, and the transfer material onto which the toner image is transferred by the transfer unit (not shown) is a heat fixing rubber roller and a pressure roller. The toner image is thermally fixed by being conveyed to the nip portion between the two. When heat-fixing the toner image, the heat-fixing rubber roller 1 comes into contact with the transfer material onto which the toner image is transferred. Here, the outer peripheral surface of the release layer 40 functions as a roller surface of the heat fixing rubber roller 1 and comes into contact with the transfer material onto which the toner image has been transferred.

[B] Manufacturing Method Each process executed when manufacturing the above-described heat fixing rubber roller 1 will be sequentially described.

[B-1] Intermediate Layer Forming Step When manufacturing the heat fixing rubber roller 1, first, the intermediate layer 20 is formed on the outer peripheral surface of the core shaft 10.

  In this embodiment, a curable silicone rubber composition is prepared as a raw material for the intermediate layer 20. Then, the silicone rubber composition is applied to the outer peripheral surface of the core shaft 10. Thereafter, the silicone rubber composition is vulcanized (heat cured) in a high temperature environment. Thereby, a uniform layer of silicone rubber is formed on the outer peripheral surface of the core shaft 10 as the intermediate layer 20.

  The formation of the intermediate layer 20 will be described more specifically.

  In the present embodiment, the silicone rubber composition that is a raw material of the intermediate layer 20 includes, for example, liquid silicone rubber as a base polymer. As the liquid silicone rubber, either an addition reaction type or a condensation reaction type can be used. In particular, it is preferable to use an addition reaction type liquid silicone rubber that is cured at a temperature of about 80 ° C. to 150 ° C. The addition-reactive silicone rubber is a polysiloxane having an addition-reactive group, and is a material that is cured by being crosslinked with a crosslinking agent.

  Note that a roughening treatment for increasing the surface roughness may be performed before forming the intermediate layer 20 on a portion where the intermediate layer 20 is formed on the outer peripheral surface of the core shaft 10. In addition, for example, after the primer layer is formed on the outer peripheral surface of the core shaft 10 by a coating method, the intermediate layer 20 may be formed on the outer peripheral surface of the core shaft 10 via the primer layer.

[B-2] Sponge Layer Formation Step Next, the sponge layer 30 is formed on the outer peripheral surface of the core shaft 10 where the intermediate layer 20 is provided. Here, the sponge layer 30 is formed on the intermediate layer 20 by forming the sponge layer 30 by an elution method.

  When forming the sponge layer 30 in this embodiment, a curable silicone rubber composition containing a water-soluble powder and triethylene glycol is prepared as a raw material for the sponge layer 30. The core shaft 10 having the intermediate layer 20 provided on the outer peripheral surface is coaxially installed inside a cylindrical mold (not shown). Then, the prepared silicone rubber composition is injected into a space located between the outer peripheral surface of the core shaft 10 and the inner peripheral surface of the cylindrical mold. Thereafter, the silicone rubber layer is formed by performing primary vulcanization on the silicone rubber composition.

  And after taking out core axis 10 in which a silicone rubber layer was formed from a metallic mold, it is immersed in water. Thus, the water-soluble powder and triethylene glycol are eluted from the silicone rubber layer into water, so that the silicone rubber layer becomes porous. Thereafter, secondary vulcanization is performed on the porous silicone rubber layer. In this way, a silicone rubber layer that is a porous layer is formed as a sponge layer 30 on the outer peripheral surface of the core shaft 10 via the intermediate layer 20.

  The formation of the sponge layer 30 will be described more specifically.

  In this embodiment, the silicone rubber composition that is a raw material of the sponge layer 30 includes, for example, liquid silicone rubber as a base polymer, and is prepared by mixing water-soluble powder and triethylene glycol.

  Of the silicone rubber composition that is the raw material of the sponge layer 30, the liquid silicone rubber can be used in both addition reaction type and condensation reaction type. In particular, it is preferable to use an addition reaction type liquid silicone rubber that is cured at a temperature of about 80 ° C. to 150 ° C.

  In the silicone rubber composition, the water-soluble powder is, for example, a sugar powder and is soluble in water as a solvent. As the water-soluble sugar powder, powders of glucose, lactose, sucrose, trehalose, fructose and the like can be used. The sugar powder may be one kind or plural kinds of powders of the above materials. Here, for example, commercially available sugar containing sucrose as a main component can be used. In particular, granulated sugar and powdered sugar can be suitably used as a water-soluble sugar powder because of its high water solubility.

  The particle size of the sugar powder is preferably 1 μm or more and 1000 μm or less. When the particle size is less than the above lower limit, a long time is required for elution of the sugar powder, and the possibility that the sugar powder remains in the sponge layer 30 increases. Further, when the particle diameter exceeds the above upper limit, the strength of the sponge layer 30 may decrease, and the durability of the heat fixing rubber roller 1 may decrease. From the above viewpoint, the particle size of the sugar powder is more preferably 10 μm or more and 400 μm or less, and still more preferably 10 μm or more and 100 μm or less. As the sugar powder, for example, a powder classified into the above particle size range using a sieve can be used.

  The content of the sugar powder is preferably 50 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the liquid silicone rubber. When the content is less than the lower limit, it becomes difficult to form the sponge layer 30 so as to include continuous bubbles. On the other hand, when the content exceeds the above upper limit value, the strength of the sponge layer 30 is lowered, and the durability of the heat fixing rubber roller 1 may be lowered. From the above viewpoint, the content of the sugar powder is more preferably 100 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the liquid silicone rubber.

  In the silicone rubber composition, triethylene glycol is a component added to increase the open cell rate of the sponge layer 30. Triethylene glycol has low compatibility with silicone rubber and high compatibility with sugar powder. For this reason, since the layer of triethylene glycol is formed around sugar powder, it can suppress that the skin layer of silicone rubber is formed between some sugar powder. Accordingly, sugar powder is easily eluted from the silicone rubber layer, and triethylene glycol is easily eluted from the silicone rubber layer. As a result, the sponge layer 30 having a high open cell rate can be formed.

  The content of triethylene glycol is preferably 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the liquid silicone rubber. When the content is less than the lower limit, it becomes difficult to form the sponge layer 30 having a sufficiently high open cell rate. On the other hand, when the content exceeds the upper limit, a large amount of triethylene glycol may remain in the sponge layer 30 and bleed from the sponge layer 30 in some cases. From the above viewpoint, the content of triethylene glycol is more preferably 5 parts by mass or more and 50 parts by mass or less, and further preferably 15 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the liquid silicone rubber.

  Similar to triethylene glycol, other polyhydric alcohols such as ethylene glycol can be suitably used because of their low compatibility with silicone rubber and high compatibility with sugar powder. Here, a monomer or oligomer having a plurality of alcoholic hydroxyl groups can be used as the polyhydric alcohol. For example, as the monomer having a plurality of alcoholic hydroxyl groups, glycerin, propylene glycol, pentaerythritol, glycerin-α-monochlorohydrin and the like can be used in addition to ethylene glycol. In addition to triethylene glycol, diethylene glycol, dipropylene glycol, polyglycerin, or the like can be used as the oligomer having a plurality of alcoholic hydroxyl groups. However, when triethylene glycol is used, the sponge layer 30 having a high open cell ratio can be formed, in particular, as compared with the case where other polyhydric alcohols are used. However, other polyhydric alcohols such as ethylene glycol may be appropriately contained in the silicone rubber composition.

  The temperature at which the primary vulcanization is performed is appropriately set depending on the type of silicone rubber used in the silicone rubber composition. For example, when the silicone rubber is a low temperature curing type (LTV silicone rubber), the primary vulcanization temperature is preferably in the range of 80 ° C. or higher and 150 ° C. or lower, and more preferably in the range of 100 ° C. or higher and 130 ° C. or lower.

  Similarly to the temperature of the primary vulcanization, the temperature at which the secondary vulcanization is performed is appropriately set depending on the type of silicone rubber used in the silicone rubber composition. For example, when the silicone rubber is a low temperature curing type (LTV silicone rubber), the secondary vulcanization temperature is preferably in the range of 180 ° C. or higher and 230 ° C. or lower, and more preferably in the range of 200 ° C. or higher and 220 ° C. or lower.

  The temperature of water used for immersion is preferably 60 ° C. or higher and 90 ° C. or lower, for example, in order to efficiently dissolve sugar powder and triethylene glycol from the silicone rubber layer. Further, the immersion time is usually 1 hour or more and 8 hours or less, and is arbitrarily set according to the thickness of the silicone rubber layer and the temperature of water used for immersion. In addition, by providing a mechanism for continuously or intermittently supplying water to the immersion tank and a mechanism for discharging the water, an elution process for eluting the sugar powder and triethylene glycol can be performed efficiently.

  In the above description, regarding the formation of the sponge layer 30, the case where the core shaft 10 taken out from the mold is immersed in water is shown, but the present invention is not limited thereto. The core shaft 10 mounted on the mold may be immersed in water without removing the core shaft 10 from the mold.

  Moreover, although the case where liquid silicone rubber was used as the base polymer of the sponge layer 30 was described above, solid silicone rubber may be used. Further, the sponge layer 30 may be formed without using a mold.

  In this case, for example, a silicone rubber sheet is prepared from a silicone rubber composition obtained by mixing sugar powder and triethylene glycol with solid silicone rubber. Then, the silicone rubber sheet is wound around the outer peripheral surface of the core shaft 10 and then vulcanized. Then, the sponge layer 30 can be formed by performing the elution process similar to the above.

  In addition, a silicone rubber cylindrical body may be produced by extrusion molding from a silicone rubber composition obtained by mixing sugar powder and triethylene glycol with solid silicone rubber. In this case, the silicone rubber cylindrical body is attached to the outer peripheral surface of the core shaft 10 and then vulcanized. Thereafter, the sponge layer 30 is formed by executing the above elution process.

[B-3] Release Layer Formation Step Next, the release layer 40 is formed on the outer peripheral surface of the core shaft 10 where the sponge layer 30 is further provided.

  In the present embodiment, the release layer 40 is formed by attaching a tube made of a release resin such as a fluororesin to the outer peripheral surface of the core shaft 10 on which the sponge layer 30 is further provided. In this case, the inner diameter of the tube formed of the releasable resin is 90% or more and 100% or less of the outer diameter of the core shaft 10 on which the sponge layer 30 is formed in order to bring them into close contact with each other. It is preferable that

  In addition, you may adhere | attach a tube on the outer peripheral surface of the sponge layer 30 using an adhesive agent. Moreover, you may perform the roughening process by the process which apply | coats a primer, chemical etching, etc. about the internal peripheral surface of a tube. In addition, in addition to the case of using a tube formed of a releasable resin, the release layer 40 may be formed by applying a releasable resin.

[C] Action and Effect As described above, in the present embodiment, the sponge layer 30 is formed by the “elution method”. That is, after forming the silicone rubber layer containing the water-soluble powder, the sponge layer 30 is formed by executing an elution process for eluting the water-soluble powder into water from the silicone rubber layer. When the sponge layer 30 is formed by the “elution method”, as described above, the core shaft 10 may corrode due to the water used in the elution treatment, and the sponge layer 30 may be peeled off from the core shaft 10. is there.

  However, in this embodiment, after forming the intermediate layer 20 on the outer peripheral surface of the core shaft 10, the sponge layer 30 is formed on the outer peripheral surface on which the intermediate layer 20 is formed by the “elution method”. The intermediate layer 20 is a homogeneous layer formed using silicone rubber, and is not a porous layer like the sponge layer 30. For this reason, the intermediate layer 20 prevents the water used in the elution process during the formation of the sponge layer 30 from affecting the outer peripheral surface of the core shaft 10. That is, in the present embodiment, the intermediate layer 20 prevents water used in the elution process from coming into contact with the outer peripheral surface of the core shaft 10. Therefore, in this embodiment, since the intermediate layer 20 functions as a corrosion prevention layer that prevents corrosion of the core shaft 10, it is possible to suppress the sponge layer 30 from being peeled off from the core shaft 10.

  Here, like the sponge layer 30, the intermediate layer 20 is formed using silicone rubber. For this reason, it can prevent effectively that peeling arises between the intermediate | middle layer 20 and the sponge layer 30. FIG.

  Moreover, corrosion of the core shaft 10 can be effectively prevented by forming the intermediate layer 20 with a thickness of 0.1 mm or more.

  As already described, when the sponge layer 30 is formed by the “elution method” using triethylene glycol, the core shaft 10 is easily corroded due to the triethylene glycol remaining in the sponge layer 30. However, in the present embodiment, the intermediate layer 20 is interposed between the core shaft 10 and the sponge layer 30. For this reason, in the present embodiment, even when the sponge layer 30 is formed using triethylene glycol, corrosion of the core shaft 10 can be effectively suppressed. As a result, the sponge layer 30 having a high open cell ratio can be easily formed.

  Even in the case where the core shaft 10 is formed of a metal material that is easily corroded due to water, such as iron or aluminum, in the present embodiment, the corrosion of the core shaft 10 is caused by the action of the intermediate layer 20. Can be effectively prevented.

  Although the embodiments of the invention have been described above, the invention is not limited to the above description, and various omissions, replacements, and changes can be made without departing from the spirit of the invention.

  Hereinafter, examples of the heat fixing rubber roller 1 will be described. In addition, in order to make an understanding easy, in description of an Example, the code | symbol is attached | subjected to each part similarly to said embodiment (refer FIG. 1, FIG. 2).

  In the example, the heat fixing rubber roller 1 in which the intermediate layer 20 was made of silicone rubber and the sponge layer 30 was made of silicone rubber was produced.

  Specifically, when producing the heat fixing rubber roller 1 of the example, first, a cylindrical core shaft 10 (outer diameter: 18 mm, material: aluminum) was prepared. And the roughening process was performed about the outer peripheral surface of the core shaft 10. FIG.

  Next, an adhesive layer was formed as a primer layer (not shown) on the portion of the outer peripheral surface of the core shaft 10 where the roughening treatment was performed. Here, after the adhesive was applied to the outer peripheral surface of the core shaft 10, the core shaft 10 was left in the oven. The temperature inside the oven was 180 ° C., and the standing time of the core shaft 10 was 20 minutes.

  Next, the intermediate layer 20 was formed in the part where the adhesive layer was formed on the outer peripheral surface of the core shaft 10. Here, after the LTV silicone rubber was applied to the outer peripheral surface of the core shaft 10, the core shaft 10 was left in the oven. The temperature inside the oven was 200 ° C., and the standing time of the core shaft 10 was 10 minutes. Thereby, the intermediate layer 20 having a thickness of 1.0 mm was formed.

  Next, a sponge layer 30 was formed on the outer peripheral surface of the core shaft 10 where the intermediate layer 20 was provided. Here, first, the following components are mixed at the following mass ratio using a stirrer for 30 minutes, and then the mixture is subjected to a vacuum defoaming treatment, whereby a curable silicone rubber composition is formed as a raw material for the sponge layer 30. Prepared as.

LTV silicone rubber: 100 parts by mass Granulated sugar powder (particle size 10-200 μm (classified with sieve)): 130 parts by mass Triethylene glycol: 25 parts by mass

  Then, after the core shaft 10 with the intermediate layer 20 provided on the outer peripheral surface is coaxially installed inside a cylindrical mold (not shown), the outer peripheral surface of the core shaft 10 and the inner peripheral surface of the cylindrical mold The prepared silicone rubber composition was injected into a space between the two. Thereafter, primary vulcanization was performed on the silicone rubber composition. The primary vulcanization was performed under the conditions that the temperature was 120 ° C. and the heating time was 30 minutes. Thereby, the silicone rubber composition was cured to form a silicone rubber layer.

  And after taking out the core axis 10 in which the silicone rubber layer was formed from the metal mold | die, it was immersed in water. Here, the core shaft 10 was immersed in water having a temperature condition of 80 ° C. for 2 hours. As a result, granulated sugar powder and triethylene glycol were eluted from the silicone rubber layer into water to make the silicone rubber layer porous.

  Thereafter, the porous silicone rubber layer was subjected to secondary vulcanization. The secondary vulcanization was performed under the conditions that the temperature was 220 ° C. and the heating time was 4 hours. Thereby, the sponge layer 30 having a thickness of 7.0 mm was formed. In this example, the open cell rate of the sponge layer 30 was 95%.

  The open cell ratio X (%) was calculated based on the following formula (1). In the formula (1), “OG” is the specific gravity of the silicone rubber composition that is the raw material of the sponge layer 30. “FG” is the specific gravity of the sponge layer 30. “DW” is the weight of the sponge layer 30. “WW” is the weight after the sponge layer 30 has absorbed water. The measurement of “WW” was performed according to the following procedure. First, in the vacuum vessel, the inside of the vacuum vessel was depressurized (10 mmHg or less) in a state where the sponge layer 30 was immersed in the vessel containing water. Then, the inside of the vacuum vessel was returned to normal pressure and left for 5 minutes, so that the sponge layer 30 absorbed water. Thereafter, the weight of the sponge layer 30 after water absorption was measured as “WW”.

  X (%) = [(WW−DW) /1.00] / [(1− (FG / OG)) × (DW / FG)] × 100] (1)

  As described above, after the sponge layer 30 was formed, the release layer 40 was formed on the outer peripheral surface of the core shaft 10 where the sponge layer 30 was formed. Here, an adhesive was applied to the outer peripheral surface of the sponge layer 30. Thereafter, a PFA tube (outer diameter 25 mm, length 227 mm, thickness 30 μm) was installed as the release layer 40. And it heated on the conditions whose temperature is 120 degreeC and heating time is 1 hour.

  Thus, the heat fixing rubber roller 1 of the example was completed.

  In order to evaluate the presence or absence of corrosion of the core shaft 10, the following tests were conducted on the heat fixing rubber roller 1 of the example. First, the sample was left in the atmosphere. Next, the outer peripheral surface of the core shaft 10 was exposed by peeling the layer provided on the core shaft 10 with a cutter. Next, the outer peripheral surface of the core shaft 10 was visually observed to evaluate the presence or absence of corrosion (rust generation) of the core shaft 10. As a result, it was confirmed that no rust was generated on the core shaft 10 in the heat fixing rubber roller 1 of the example.

  On the other hand, in the formation of the intermediate layer 20, if butyl rubber or fluoro rubber is used instead of silicone rubber, the adhesive strength between the intermediate layer 20 and the sponge layer 30 is lowered, so that the corrosion of the core shaft 10 can be suppressed. However, the core shaft 10 and the sponge layer 30 may be peeled off.

  As can be seen from this result, in the embodiment, the intermediate layer 20 can prevent the water used in the elution process when the sponge layer 30 is formed from affecting the outer peripheral surface of the core shaft 10. For this reason, it is possible to prevent the core shaft 10 from being corroded. In addition, as in the embodiment, by forming the intermediate layer 20 with silicone rubber in the same manner as the sponge layer 30, it is possible to effectively prevent peeling between the intermediate layer 20 and the sponge layer 30. .

DESCRIPTION OF SYMBOLS 1 ... Rubber roller for heat fixing, 10 ... Core shaft, 20 ... Intermediate layer, 30 ... Sponge layer, 40 ... Release layer, AX ... Rotating shaft

Claims (4)

An intermediate layer forming step of forming an intermediate layer on the outer peripheral surface of the core shaft formed of a metal material;
A sponge layer forming step of forming a sponge layer on the outer peripheral surface of the core shaft via the intermediate layer,
In the sponge layer forming step, the sponge layer is formed by eluting the water-soluble powder into water from the silicone rubber layer after forming the silicone rubber layer containing the water-soluble powder.
In the intermediate layer forming step, the intermediate layer is formed using silicone rubber.
Manufacturing method of rubber roller for heat fixing. In the intermediate layer forming step, the intermediate layer is formed so as to have a thickness of 0.1 mm or more.
The method for producing a rubber roller for heat fixing according to claim 1. In the sponge layer forming step,
The silicone rubber layer further contains triethylene glycol,
The sponge layer is formed by eluting the triethylene glycol together with the water-soluble powder from the silicone rubber layer.
A method for producing a heat-fixing rubber roller according to claim 1. The core shaft is formed using iron or aluminum.
4. A method for producing a heat fixing rubber roller according to claim 1.

Images