JP2009157205A - Oa equipment roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an OA equipment roller whose surface layer is formed by applying and baking fluororesin, the roller being excellent in various characteristics without degrading releasability and heat conductivity and suitable for mass production. <P>SOLUTION: The OA equipment roller has an elastic layer and a surface layer formed in order on the surface of the metal core, wherein the surface layer is formed from a plurality of fluororesin layers and has a thickness of 6-30 μm, and at least one of the plurality of fluororesin layers forming the surface layer contains filler, and the outermost layer of the plurality of fluororesin layers forming the surface layer does not contain filler, and at least one of the fluororesin layers except the outermost layer contains filler. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a roller for an OA device used for a fixing roller or a pressure roller of a fixing unit of an OA device such as a copying machine, a developing roller or a charging roller of a developing unit.

  This type of roller generally forms a rubber layer as an elastic layer on the outer periphery of a core metal, and further, PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether resin) or PTFE (polytetrafluoroethylene) as a surface layer on the elastic layer. A fluororesin layer such as fluoroethylene) or FEP (fluorinated ethylene propylene resin) is formed to provide a release property.

  By the way, in order to improve the durability and the like with high functions such as fixing and developing, and in order to improve durability, the surface layer of the roller for OA equipment has conductivity, thermal conductivity, wear resistance, Various fillers are added to impart functions such as strength.

  However, when a filler is added, there is a problem that the releasability of the fluororesin layer is lowered, and there is a problem that flexibility necessary for obtaining high image quality is impaired. It is extremely difficult to obtain a roller for equipment.

  Therefore, the fluororesin layer is made into a plurality of layers, and the functional layer to which various functions are added by adding fillers is positioned inside, while the layer that does not contain filler is used as the outermost layer to release the fluororesin layer. It is possible to have a structure that secures this. In addition, such a structure has an advantage that pinhole defects can be reduced by using a plurality of layers.

However, when a plurality of fluororesin layers are used, depending on the method for forming the fluororesin layer, the thickness of the fluororesin layer may increase or the elastic layer may deteriorate.
For example, in the powder coating method in which a fluororesin layer is formed using fluororesin powder, the thickness of one layer is 20 μm or more. Therefore, if multiple layers are used, the total thickness of the fluororesin layer is as large as 40 μm or more. Therefore, there is a problem that it is difficult to cope with speeding up, and that the thick surface layer impairs flexibility and inferior image quality performance.

  In addition, when applying a method of forming a surface layer using a thin tube made of fluororesin (Patent Document 1) to form a surface layer made of a plurality of layers of fluororesin, on the rubber layer (elastic layer), After mounting a plurality of fluororesin tubes, it is necessary to join the tubes by firing. At this time, since it is necessary to fire at a high temperature of 400 ° C. or higher, there is a problem that the rubber layer inferior in heat resistance as compared with the fluororesin deteriorates and is not suitable for practical use. In addition, in the case of a method using a tube, there is a problem that handling is difficult and expensive, and a roller for OA equipment provided with a surface layer composed of a plurality of fluororesin layers has not been put into practical use.

  On the other hand, as a method for forming a thin fluororesin layer, there is a method using a fluororesin dispersion.

  One method for forming a fluororesin layer using such a fluororesin dispersion is to apply a fluororesin dispersion on the outer peripheral surface of the rubber layer and then firing it to form the fluororesin layer. . However, in this method, if it is intended to obtain a surface layer having good characteristics, it is necessary to perform sufficient firing over a long time. However, when firing for a long time, 400 ° C. as in the method using the tube. Since it is necessary to bake at the above high temperature, there exists a problem that the rubber layer inferior to heat resistance compared with a fluororesin deteriorates.

  On the other hand, as a method of forming a fluororesin layer using a dispersion of fluororesin, and forming a surface layer without affecting the heat when the fluororesin is fired on the rubber layer, a method for manufacturing a roller for OA equipment Then, a fluororesin dispersion is applied to the inner peripheral surface of the cylindrical mold and fired to form a fluororesin layer, and then a cored bar is inserted into the hollow of the cylindrical mold, and the fluororesin There is a method of manufacturing a roller by injecting a material for forming a rubber layer between a layer and a core metal, vulcanizing, and then drawing the product from a cylindrical mold (hereinafter also referred to as demolding). According to this method, since the rubber layer is not affected by the firing temperature, the fluororesin can be completely fired and the deterioration of the rubber layer can be prevented.

  However, in the case of the above method, after the product is pulled out from the cylindrical mold, the surface active agent, film thickener and thickener contained in the paint (fluororesin dispersion) are added to the inner peripheral surface of the cylindrical mold. It was found that the decomposition product remained as a decomposition product during firing, and when it was repeatedly used, the releasability of the inner peripheral surface of the cylindrical mold was lowered, and finally it was impossible to remove the mold from the mold. Moreover, it was found that the cleaning operation of the cylindrical mold for removing these residues in order to restore the mold release property is very troublesome and is not suitable for mass production.

  As described above, in the conventional roller for OA equipment, it is difficult to form a thin fluororesin layer. Therefore, when a surface layer composed of a plurality of fluororesin layers is formed, the surface layer becomes thick and the thermal conductivity is increased. There is a problem that it is difficult to cope with a high speed due to a decrease in image quality, and a problem that the flexibility of the surface layer is lost and the image quality performance is inferior. For this reason, it has been difficult to provide a roller for OA equipment that is excellent in various functions, can cope with higher speed, and can obtain high image quality.

JP 2004-276290 A

  Accordingly, an object of the present invention is to provide a roller for office automation equipment that is excellent in various characteristics, can cope with high speed, and can obtain high image quality.

  The fluororesin dispersion generally contains about 15 to 20 wt% of a surfactant for the dispersion stability of the fluororesin and for improving the wettability with the adherend. Further, in order to improve the film formability, about 10 to 15 wt% of a film thickener and a thickener are contained.

However, it has been found that when firing is insufficient, a surfactant, a film thickener and a thickening agent remain in the fired fluororesin layer, thereby reducing the releasability of the fluororesin layer.
Therefore, as a result of intensive studies, when the film is made sufficiently thin, film formation is possible even if the surfactant, film thickener and thickener are reduced, and the surfactant, film thickener and When the thickener is reduced, it is possible to eliminate the residual of these surfactants, film thickeners and thickeners without performing sufficient firing for a long time, and it is not necessary to reduce the releasability. I understood. That is, it was found that a fluororesin layer having both thin film thickness and releasability can be formed by the above method.

  Moreover, according to this method in which the surface active agent, the film thickener and the thickener contained in the fluororesin dispersion are reduced while the film is thinned, it can be fired in a short time, so the deterioration of the rubber layer due to the firing temperature. It was found that an excellent roller for OA equipment can be produced.

  Further, in the method of forming a fluororesin layer by applying a fluororesin dispersion on the inner surface of the cylindrical mold and then firing, the residue on the inner surface of the cylindrical mold is a surfactant, a film thickener as described above. And was found to be a degradation product of the thickener.

  And it became clear that adhesion of a foreign material does not generate | occur | produce by significantly reducing the said surfactant, a film thickener, and a thickener. Thus, in the method of forming a fluororesin layer using a cylindrical mold, the rubber layer is completely removed by applying the fluororesin dispersion greatly reduced in the surfactant, film thickener and thickener. It has been found that a roller for OA equipment suitable for mass production can be produced without being deteriorated and sufficiently fired.

  In this way, since a roller having a thin surface layer can be realized, it is possible to provide good thermal conductivity and flexibility, and to provide a roller for office automation equipment that can achieve high image quality and high speed. it can.

  Furthermore, since it is possible to form a thin film, even if a plurality of layers are formed, it is possible to ensure good thermal conductivity, and by assigning different functions to each layer while supporting high speed, It is possible to provide a roller for office automation equipment, which has been difficult to achieve even more than one layer.

  Furthermore, by making the surface layer into a plurality of layers, pinhole defects can also be reduced, and an inexpensive roller for OA equipment can be provided by improving the yield.

  When the thickness of the surface layer was examined, it was difficult to function as a surface layer when the thickness was less than 6 μm, and when it exceeded 30 μm, the flexibility was low and the image performance was insufficient, and the thermal conductivity was low and high speed. It was found that the function corresponding to the conversion was insufficient.

  Moreover, it is preferable that content of the surfactant, the film thickener, and the thickener contained in the fluororesin dispersion is 1.0 to 5 wt% or less with respect to the fluororesin dispersion as a total amount.

Therefore, the present invention provides the following:
It is a roller for OA equipment in which an elastic layer and a surface layer are formed in order on a core metal,
The surface layer includes a plurality of fluororesin layers, and has a thickness of 6 to 30 μm.

  The invention of claim 1 may be any roller for OA equipment comprising a plurality of fluororesin layers and having a surface layer with a thickness of 6 to 30 μm, and its specific production method is not particularly limited. Absent.

When laminating the plurality of fluororesin layers, applying the fluororesin dispersion after improving the wettability of the surface of the fluororesin layer formed earlier, for example, by plasma treatment, electrical discharge machining, chemical etching, etc. It is preferable because a smooth and thin film having better adhesion can be formed.
In order to improve wettability with the elastic layer or the like, it is preferable to perform plasma treatment or the like on the surface of the fluororesin layer.

  Further, the elastic layer is not particularly limited, and various elastic layers can be applied. For example, various rubbers such as solid rubber and sponge rubber (balloon rubber) can be applied.

  The core metal of the OA equipment roller in the present invention is preferably made of, for example, aluminum, iron, carbon steel, stainless steel, or the like.

The invention described in claim 2
2. The OA equipment roller according to claim 1, wherein the surface layer has a thickness of 6 to 20 μm.

The invention of this claim can further improve the thermal conductivity when the thickness of the surface layer is 6 to 20 μm.
The total thickness of the multiple fluororesin layers is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less.

The invention according to claim 3
Of the plurality of fluororesin layers forming the surface layer,
The roller for OA equipment according to claim 1 or 2, wherein at least one layer is a fluororesin layer containing a filler.

  In the present invention, at least one of the plurality of fluororesin layers forming the surface layer is a fluororesin layer containing a filler, so that the surface layer has conductivity, thermal conductivity, wear resistance, strength. Functions such as improvement can be imparted. For this reason, it is excellent in various characteristics and can provide the roller for OA apparatus which can obtain a higher function.

Examples of the conductive filler include metal powders such as C and Al, ion salts, and the like, and examples of the filler having thermal conductivity and wear resistance include SiC, TiO ₂ , and BN.

The invention according to claim 4
Of the plurality of fluororesin layers forming the surface layer,
The outermost layer is a roller for OA equipment according to claim 3, which is a fluororesin layer containing no filler.

  In the invention of this claim, among the plurality of fluororesin layers forming the surface layer, the outermost layer is a fluororesin layer containing no filler, and at least one layer excluding the outermost layer contains a filler. Since it is a fluororesin layer, it is possible to provide a roller for office automation equipment that can ensure the flexibility of the surface layer and good releasability, is excellent in various properties, and can obtain higher functions.

The invention described in claim 5
The OA equipment roller according to any one of claims 1 to 4, wherein the fluororesin is at least one of PFA, PTFE, and FEP.

  In the invention of this claim, since PFA, PTFE, or FEP is used as the fluororesin, the surface layer is more excellent in heat resistance and releasability.

The invention described in claim 6
The filler is at least one of a filler for imparting conductivity, a filler for improving thermal conductivity, a filler for improving wear resistance, and a filler for improving strength. The roller for OA equipment according to any one of claims 1 to 5.

  In the invention of this claim, since the filler for imparting conductivity to the fluororesin of the surface layer or improving the thermal conductivity, wear resistance and strength is contained, the surface layer with improved various functions and Become.

The invention described in claim 7
The OA equipment roller according to any one of claims 1 to 6, wherein an intermediate layer is provided between the elastic layer and the surface layer.

According to the present invention, since an intermediate layer is provided between the elastic layer and the surface layer, in addition to the above effects, a roller for OA equipment that can further meet various user-specified specifications can be provided.
The intermediate layer may be a layer made of an adhesive.

  In the present invention, it is possible to provide a roller for OA equipment that is excellent in various characteristics, can cope with high speed, and can obtain high image quality.

  Hereinafter, the present invention will be specifically described with respect to the best mode thereof. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram schematically showing a roller for office automation equipment according to an embodiment of the present invention, in which (a) is a cross-sectional view in a method perpendicular to the roller axis, and (b) is a perspective view. . FIG. 2 is a perspective view schematically showing a method for manufacturing a roller for OA equipment according to an embodiment of the present invention.
The roller 1 for OA equipment has an elastic layer 3, an intermediate layer 4, and a surface layer 5 formed in order on a cored bar 2, and the surface layer 5 includes a first surface layer (outer layer) 5 a and a second surface layer (inner layer). It consists of two layers of 5b. The roller 1 for OA equipment is manufactured by forming layers in the order of the first surface layer 5 a → second surface layer 5 b → intermediate layer 4 → elastic layer 3 using a cylindrical mold 6. Specifically, it is as follows.

(1) A fluororesin dispersion in which surfactants, film thickeners and thickeners are greatly reduced is applied to the inner peripheral surface of the cylindrical mold 6 (for example, flow coating), and the cylindrical mold is used as the center of the axis. After rotating and drying, complete firing is performed at a temperature higher than the melting point of the fluororesin (upper limit 400 ° C.) to form the first surface layer (outer layer) 5a (a fluororesin layer having a thickness of 3 to 10 μm). .
In addition, as the surfactant, there are ionic and nonionic (nonionic) such as cationic and anionic, and specifically, the ionicity includes a carboxylic acid, sulfonic acid or phosphoric acid structure as a hydrophilic group. Anionic and cationic groups having tetraalkylammonium or the like in the hydrophilic group can be mentioned, and nonionic properties can be exemplified by low molecular weight systems such as alkylglycosides and high molecular weight systems such as polyethylene glycol. .

(2) Next, in order to improve adhesiveness, wettability, and hydrophilicity, an inner surface treatment (for example, plasma treatment) is performed on the inner peripheral surface side of the first surface layer 5a.

(3) Next, a fluororesin dispersion containing a filler is further applied to the inner peripheral surface of the first surface layer 5a (for example, flow coating), and the surfactant, film thickener and thickener are greatly reduced. After being dried, complete firing is performed at a high temperature equal to or higher than the melting point of the fluororesin (upper limit 400 ° C.) to form a second surface layer (inner layer) 5b (a fluororesin layer having a thickness of 3 to 10 μm).

(4) Next, the inner surface treatment (for example, plasma treatment) of the second surface layer 5b is performed.

(5) In the case of forming the intermediate layer, next, various functional rubbers are applied to the inner peripheral surface of the second surface layer 5b (for example, flow coating), and the cylindrical mold 6 is rotated about the axis. Drying is performed to form the intermediate layer 4 (thickness: 50 to 150 μm).

(6) Next, after inserting the core metal 2 into the hollow of the cylindrical mold coaxially with the cylindrical mold, the foamed rubber is injected into the gap between the intermediate layer 4 and the core metal 2. The elastic layer 3 (thickness 1.5 to 3.5 mm) is formed by vulcanization.

(7) Thereafter, the OA machine roller 1 is removed from the cylindrical mold 6.

  In the present embodiment, the roller for office automation equipment manufactured using the cylindrical mold 6 has been described. However, the fluororesin dispersion was applied to the surface of the rubber layer or the intermediate layer without using the cylindrical mold 6. Thereafter, the roller for OA equipment of the present invention can also be prepared by a method of firing.

  Hereinafter, based on an Example, it demonstrates concretely.

(1) Formation of surface layer (a) Formation of first surface layer (outer layer) On the inner surface of a stainless steel cylindrical mold having an inner diameter of 18 mmφ and a length of 257 mm, 60 vol% PFA and an interface of 5 wt% with respect to PFA A PFA dispersion containing an activator (manufactured by DuPont: EMX-047) is applied, and then dried at room temperature for 10 minutes while rotating the cylindrical mold around the axis, and then at 400 ° C. for 30 minutes. By heating and firing completely, a first surface layer having a thickness of 6 μm was formed on the inner peripheral surface of the cylindrical mold.

(B) Formation of the second surface layer (inner layer) Next, after plasma-treating the inner surface of the first surface layer, 14.5 vol% of SiC filler and 1. A dispersion containing 07% and a thickener (methylcellulose) 1% (DuPont: EMX-041-2) was applied, and then dried at room temperature for 10 minutes while rotating the cylindrical mold around the axis. Then, the second surface layer having a thickness of 6 μm was formed on the inner peripheral surface of the cylindrical mold by heating at 400 ° C. for 30 minutes to complete firing.

(2) Formation of intermediate layer Next, after plasma-treating the inner surface of the second surface layer, Si rubber (high heat conductive rubber) (X32-2020, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the inner peripheral surface of the second surface layer 5b ( The intermediate layer 4 having a thickness of 100 μm was formed by drying by rotating the cylindrical mold 6 around the axis.

(3) Formation of elastic layer (A) Casting Next, an aluminum cored bar 2 is inserted into the hollow of the cylindrical mold, and Si foam rubber (in the gap between the intermediate layer 4 and the cored bar 2) Balloon rubber) (manufactured by Shin-Etsu Chemical Co., Ltd .: X34-2061-28L) was injected.

(B) Primary vulcanization The temperature was raised to 160 ° C., maintained for 15 minutes (including the temperature rise time), and primary vulcanization was performed to form an elastic layer 3 having a thickness of 1.5 mm.

(C) Demolding Subsequently, when the roller 1 for OA equipment was demolded from the cylindrical mold 6, no foreign matter was confirmed on the inner surface of the cylindrical mold. The surface layer could be formed by complete firing, and the thickness of the entire surface layer was 12 μm.

(D) Secondary vulcanization The temperature was raised to 250 ° C. and maintained for 30 minutes (including the temperature raising time) to perform secondary vulcanization.

(4) Cutting / Finishing After cutting off the portions near each end of each formed layer, cleaning was performed, and appearance inspection was performed to produce a roller for OA equipment.

In this embodiment, by making the surface layer thin and further providing an intermediate layer made of high thermal conductive rubber, manufacturing a roller for office automation equipment that can improve thermal conductivity and cope with high speed. I was able to. In addition, since the surface layer is a layer composed of two fluororesin layers and the first surface layer is a fluororesin layer to which no filler is added, flexibility and good releasability are ensured, so high image quality can be obtained. Furthermore, since the wear resistance and strength were improved by adding a SiC filler to the second surface layer, a roller for OA equipment having excellent durability could be produced.
When this roller for OA equipment was evaluated as a pressure roller, desired performance was obtained, and there was no problem in the adhesion between the layers.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the roller for OA equipment which concerns on one Embodiment of this invention, Comprising: (a) is sectional drawing of an orthogonal direction with an axis | shaft, (b) is a perspective view. It is a perspective view which shows typically the manufacturing method of the roller for OA equipment which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Roller for OA equipment 2 Core metal 3 Elastic layer 4 Intermediate layer 5 Surface layer 5a First surface layer (outer layer)
5b Second surface layer (inner layer)
6 Cylindrical mold

Claims (7)

It is a roller for OA equipment in which an elastic layer and a surface layer are formed in order on a core metal,
The said surface layer consists of a some fluororesin layer, and thickness is 6-30 micrometers, The roller for OA equipment characterized by the above-mentioned.   The roller for office automation equipment according to claim 1, wherein the surface layer has a thickness of 6 to 20 μm. Of the plurality of fluororesin layers forming the surface layer,
The roller for office automation equipment according to claim 1 or 2, wherein at least one layer is a fluororesin layer containing a filler. Of the plurality of fluororesin layers forming the surface layer,
The roller for OA equipment according to claim 3, wherein the outermost layer is a fluororesin layer containing no filler.   The roller for office automation equipment according to any one of claims 1 to 4, wherein the fluororesin is at least one of PFA, PTFE, and FEP.   The filler is at least one of a filler for imparting electrical conductivity, a filler for improving thermal conductivity, a filler for improving wear resistance, and a filler for improving strength. The roller for OA equipment according to any one of claims 1 to 5.   The roller for OA equipment according to any one of claims 1 to 6, wherein an intermediate layer is provided between the elastic layer and the surface layer.

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