JP2004255828A - Composite belt and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite belt showing an improved adhesive force between an elastic body layer and a fluororesin layer, and a method for manufacturing the composite belt. <P>SOLUTION: A seamless composite tubular product has tubular base material layers (1 and 5), the elastic body layer (2) and the fluororesin layer A (3) laminated in this order. In an interface between the elastic body layer (2) and the fluororesin layer A (3), a recessed part is formed on the elastic body layer (2) and filled with a fluororesin B (4). In addition, the fluororesin B and the fluororesin layer A are integrally fusion-bonded together. In the composite belt and the method for manufacturing the composite belt, the recessed part is formed by sandblasting the surface of the elastic body layer (2) after vulcanization, then the recessed part in the surface of the elastic body layer (2) is impregnated with the particles of the fluororesin B by applying a solution containing the fluororesin B and a fluororesin A is applied for coating. Finally, the fluororesin B and the fluororesin layer (A) are fusion-bonded in one piece by calcining the fluororesin B and the fluororesin layer (A) at temperatures above the melting points of the fluororesins A and B. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite belt used in a color image forming apparatus such as an electrophotographic copying machine, a laser beam printer, and the like, and a method for manufacturing the same, and preferably in a heat fixing machine of the color image forming apparatus. The present invention relates to a composite belt used as a fixing belt of a belt fixing system for fixing a color toner image transferred onto a transfer material such as paper by heating, and a manufacturing method thereof.
[0002]
[Prior art]
In image forming devices such as copiers using electrophotographic technology, leather beam printers, and facsimile machines, at the final stage of printing or copying, the toner image on a sheet-like transfer material such as paper is heated and melted for transfer. It is fixed on paper. As a means for fixing an image, a heat roller fixing method is widely used as shown in FIG. That is, the toner 46 is heated and melted while sequentially feeding the copy paper 43 on which the toner image is formed between the fixing roller 41 having the heater 45 and the pressure roller 42 in pressure contact therewith, and the toner image 47 is copied. It is fixed on the paper 43. Reference numeral 44 denotes a thermistor.
[0003]
However, the heating roll fixing method has a problem that the waiting time until the fixing roll reaches a predetermined temperature is long. That is, a waiting time occurs after the power is turned on until the fixing roll reaches a predetermined fixing temperature. At the same time, since the entire fixing roll must be heated, power consumption is large.
[0004]
In recent years, a belt fixing system as shown in FIG. 7 has been developed to reduce the waiting time and to save power. As an example of the belt fixing system, two support rolls 52 and 53 and a heater 54 are provided at a predetermined interval inside a fixing belt 51 made of polyimide resin or the like, and a toner is interposed between a pressure roll 55 in pressure contact with the heater 54. This is a system in which the toner image 58 is fixed on the copy paper 56 by heating and melting the toner while sequentially feeding the copy paper 56 on which the image 57 is formed.
[0005]
In the belt fixing method, since the heater substantially directly heats the toner through a thin film-like polyimide resin belt or the like, the heating unit reaches a predetermined fixing temperature in a short time, and thus, as in the heat roller method. It is not necessary to preheat the roller in advance, there is no waiting time from when the power is turned on until it can be fixed, power consumption is small, and power can be saved.
[0006]
The fixing belt used in the belt fixing system needs to have heat resistance that can withstand the melting temperature of the toner, and mechanical characteristics that can withstand repeated use, such as rotation, pressure bonding, wear resistance, and tensile strength. As a typical material of the fixing belt and its constitution, a composite tubular material having a polyimide resin tubular material as an inner layer base material and a fluororesin outer layer on its outer surface is used.
[0007]
Such a composite tubular article is known from Patent Document 1 below. That is, in the manufacturing method, after the precursor liquid of the tubular molding is adhered to the outer surface of the core in advance to be thicker than the final film molding thickness, an outer mold having an inner diameter of a predetermined gap with respect to the outer diameter of the core ( The die is inserted into the core body coated with the precursor liquid and allowed to pass through the surface of the core body. After that, a predetermined tubular material is obtained by means such as heating, and then the outer layer of the tubular material is coated with a fluororesin and fired. Thus, a composite tubular product can be manufactured.
[0008]
However, composite tubular products made of polyimide resin and fluororesin manufactured as described above are satisfactory when used in fixing devices such as color copying machines and color printers where higher image quality fixing properties are required. Cannot be obtained.
[0009]
In fixing color toners, it is necessary to sufficiently heat and mix four colors of red, blue, yellow and black toners so that the intermediate colors and shades are clear. Since there is no elasticity, color toner cannot be mixed sufficiently and high image quality cannot be fixed. That is, in order to thermally fix a color toner image, it is necessary to melt several colors of toner completely and wrap and mix the toner image with elastic force or a soft surface layer, unlike the fixing of a single color toner.
[0010]
Therefore, Patent Document 2 below proposes a fixing belt in which an elastic layer made of silicone rubber or fluorine rubber is molded on the outermost layer, that is, the surface in contact with the toner. Patent Document 3 below proposes a tubular inner layer made of a conductive polyimide resin, and a composite tubular material having a two-layer structure made of conductive silicone rubber or conductive fluororubber on the outer peripheral surface thereof. Tubular objects provided with a heat-resistant release protection layer made of fluororesin or silicone material have been proposed.
[0011]
As described above, the fixing belt for the color toner image retains the mechanical properties necessary for fixing with the polyimide resin base layer, and has a silicone rubber elastic layer on the outer layer, and further has a heat-resistant release agent such as a fluororesin or a silicone resin on the outer layer. High image quality can be obtained with a structure having layers.
[0012]
[Patent Document 1]
Japanese Patent No. 3054010
[0013]
[Patent Document 2]
JP-A-5-154963
[0014]
[Patent Document 3]
JP 10-305500 A
[0015]
[Problems to be solved by the invention]
However, silicone rubber and fluororesin, which are elastic layers, are substances that are excellent in releasability from each other, and it is very difficult to adhere both substances, especially when the hardness of the elastic layer is low, It is difficult to improve the adhesion of the fluororesin layer. On the other hand, the characteristics required for fixing belts require heat resistance, mechanical durability, releasability, flexibility and other characteristics. Especially in the fixing belt with the above structure, the adhesion or adhesion of each layer is sufficient. Otherwise, delamination may occur, causing wrinkles or cracks in the outermost layer in contact with the toner image.
[0016]
In order to solve the above-described conventional problems, an object of the present invention is to provide a composite belt having improved adhesion between an elastic body layer and a fluororesin layer and a method for producing the same.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the composite belt of the present invention is a seamless composite tubular article comprising a tubular base material layer, an elastic body layer, and a fluororesin layer (A) in this order,
A concave portion is formed at the boundary surface between the elastic body layer and the fluororesin layer (A) and on the elastic body layer side,
A fluororesin (B) is embedded in the recess,
The fluororesin (B) and the fluororesin layer (A) are fused and integrated.
[0018]
The method for producing a composite belt of the present invention is a method for producing a seamless composite tubular article comprising a tubular base material layer, an elastic body layer, and a fluororesin layer (A) in this order,
The elastic layer is molded and vulcanized on the outer surface of the base material layer,
The elastic layer surface after vulcanization is sandblasted to form a recess,
Applying a solution containing a fluororesin (B) to the elastic body surface and impregnating the concave portions of the surface with fluororesin (B) particles,
Next, the fluororesin (A) is coated,
Then, the fluororesin (B) and the fluororesin layer (A) are fused and integrated by firing at a temperature equal to or higher than the melting point of the fluororesin (A) (B).
[0019]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a recess is formed at the boundary surface between the elastic body layer and the fluororesin layer (A) and on the elastic body layer side, and the fluororesin (B) is embedded in the recess, and the fluororesin (B ) And the fluororesin layer (A) are fused and integrated. That is, the anchor-shaped fluororesin (B) is formed on the boundary surface between the elastic layer and the fluororesin (A), and the fluororesin (B) and the fluororesin layer (A) are fused and integrated. Thereby, the adhesive force of an elastic body layer and a fluororesin layer is increasing.
[0020]
The peel strength between the fused fluororesin layers (A) and fluororesin (B) and the elastic body layer (hereinafter also referred to as “adhesion”) is preferably 100 g or more in a 1 cm width.
[0021]
Further, when the fusion-bonded fluororesin layer (A) and fluororesin (B) are peeled off from the elastic layer, the elastic layer cohesively breaks. That is, when the fusion-bonded fluororesin layer (A) and fluororesin (B) are peeled off from the elastic body layer, the elastic body layer is destroyed and is stuck to the fluororesin film and peeled off. This cohesive failure can be clearly observed with the naked eye. This is because a concave portion is formed on the surface of the elastic body layer, and the fluororesin (B) is embedded in the concave portion to form a strong anchor and fused and integrated with the fluororesin layer (A). In addition, as a feature of the production method of the present invention, when the surface of the elastic layer is sandblasted to form a recess, and the recess is impregnated with fluororesin (B) particles, the rubber hardness of the elastic layer is compared. It is presumed that the fluororesin (B) particles are sandwiched in the recesses on the surface of the elastic layer to form a strong anchor.
[0022]
The base material layer is preferably at least one selected from polyimide resin and metal. This is because both have heat resistance and durability.
[0023]
The elastic body is preferably at least one selected from silicone rubber and fluororubber.
[0024]
The fluororesin (A) is at least one selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) or It is a mixture thereof, and the fluororesin (B) is preferably polytetrafluoroethylene (PTFE).
[0025]
The rubber hardness of the elastic layer is preferably 3 degrees or more and 70 degrees or less in JIS A hardness. The thickness of the elastic layer is preferably 30 μm or more and 1500 μm or less.
[0026]
Next, in the manufacturing method of the present invention, the method of molding an elastic body layer on the outer surface of the base material layer has an outer diameter of the tubular base material and a predetermined gap, and is formed on the outer surface of the tubular base material. On the other hand, the elastic precursor is discharged while being controlled at a predetermined speed by a discharge molding machine having a slit for discharging the elastic precursor from the outside, and at least one selected from the tubular base material and the discharge molding machine It is preferable to mold the elastic layer with a predetermined film thickness on the outer surface of the base material layer while moving the substrate. In this way, the film thickness becomes uniform, even a long product can be formed, the raw material loss can be reduced, and a new raw material is always used.
[0027]
In firing the fluororesins (A) and (B), the ambient temperature is preferably set to 400 ° C. or higher. This is for fusion integration of the fluororesins (A) and (B). The firing time is preferably 10 minutes or less. By firing under such conditions, the fluororesin can be fired without thermally degrading the rubber elastic layer.
[0028]
According to the composite belt of the present invention, an elastic body having sufficient softness to mix and melt a plurality of toners such as red, blue, yellow, or black in a color toner image heat fixing device and heat fix them on a copy paper. It has a layer and a releasing layer for preventing offset, and the color toner is sufficiently melted and wrapped and fixed to obtain a clear and high image quality.
[0029]
In the case of a composite belt of a low hardness elastic body layer and a fluororesin layer as in the present invention, the amount of deformation of the rubber elastic body layer increases due to the pressure applied by the fixing device, and naturally the fluororesin layer and the rubber elastic body At the boundary of the layers, each layer moves differently and leads to wrinkles. That is, in a composite of a rubber elastic layer and a fluororesin layer, the rubber elastic layer is inversely proportional to its hardness and is deformed in proportion to the pressure applied during fixing. However, the amount of deformation of the fluororesin layer is small, and in the part where the pressure is applied, the fluororesin layer is also deformed following the amount of deformation of the rubber elastic layer, and then the applied pressure of the composite belt is removed. In addition to the restoration of the rubber elastic layer, the fluororesin layer also tries to restore on the surface of the rubber elastic layer, but it does not restore completely like the rubber elastic layer, so a locally deformed state accumulates. If the operation of the fixing device is continued as it is, wrinkles are generated on the surface of the fluororesin, fine cracks are generated with the wrinkles as the core, and toner adheres to these portions, resulting in a defective image.
[0030]
By providing a fluororesin anchor layer (an anchor shape) at the boundary surface between the elastic layer and the fluororesin layer as in the present invention, both layers are firmly adhered, and the fluororesin layer can follow the deformation of the rubber layer and has low hardness. High-quality images can be obtained due to the effect of enveloping the toner with the rubber elastic layer and the releasability of the fluororesin.
[0031]
As an example of the size of the composite belt of the present invention, the diameter is 20 to 100 mm and the length is about 350 mm. Of course, it may be smaller than this, for example, for A4 size, or any larger size can be obtained.
[0032]
Next, specific embodiments of the present invention will be described. FIG. 1 is a cross-sectional view of a composite belt according to an embodiment of the present invention, which includes a polyimide resin layer 1, an elastic body layer 2, and an outermost release layer 3. FIG. 2A is a schematic sectional view enlarging this. Between the elastic body layer 2 and the outermost release layer 3, there is a fluororesin (B) 4 embedded in a throwing manner. FIG. 2B shows an example in which the base material layer is replaced with the polyimide resin layer 1 and the metal layer 5 is made of stainless steel or the like. Reference numerals 10 and 11 denote composite belts.
[0033]
As an example, a polyimide precursor solution is used for the polyimide resin tubular material that becomes the base layer of the composite belt shown in FIG. 2A. The polyimide precursor solution can be obtained, for example, by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine component in an organic polar solvent. The following are typical examples of such aromatic tetracarboxylic acids. Pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,3,4,4 '-Biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2-bis (3 4-Dicarboxyphenyl) ether dianhydride, or these tetracarboxylic acid esters and mixtures of the above tetracarboxylic acids may be used, and are not limited as long as the characteristics of the base layer of the composite belt can be obtained.
[0034]
On the other hand, the aromatic diamine component is not particularly limited, and paraphenylenediamine, metaphenylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminophenylmethane, benzidine, 3,3′-diaminodiphenylmethane, 3, Examples include 3′-dimethoxybenzidine, 4,4′diaminodiphenylpropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and the like.
[0035]
In the production method of the present invention, a tubular product is produced using a composition (raw material) in which a polyimide precursor is dissolved in an organic polar solvent. Examples of the organic polar solvent in the previous period include dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, phenol, o-, m-, p-cresol, and the like. These organic polar solvents can be mixed with hydrocarbons (hydrocarbons) such as xylene, hexane and toluene.
[0036]
In addition, a thermal conductivity improving agent such as boron nitride or metal powder may be mixed in a polyimide precursor liquid obtained by polymerizing an aromatic tetracarboxylic acid component and an aromatic diamine component in an organic polar solvent. .
[0037]
The elastic layer is made of silicone rubber, fluoro rubber, or a mixture thereof. Examples of the silicone rubber include liquid room temperature curable silicone rubber (silicone RTV) that is commercially available. The fluororubber is used in a liquid state, and examples thereof include commercially available FKM (VDF-HFP fluorine binary and ternary copolymers) latex. Further, boron nitride or a metal filler for improving thermal conductivity can be mixed in these elastic layers. The rubber hardness of the elastic layer is preferably 3 degrees or more and 70 degrees or less in JIS A hardness, and the range of 10 degrees to 50 degrees is most preferable from the effect of enveloping the color toner.
[0038]
The thickness of the rubber elastic body layer is preferably 30 μm to 1500 μm, more preferably 500 μm or less from the viewpoint of the thickness of the fluororesin layer that can follow the deformation of the rubber elastic body layer or the heat conductivity of the rubber elastic body layer. On the other hand, when the thickness is less than 30 μm, the elastic force is poor and the effect of enveloping the toner is reduced.
[0039]
At the same time, regarding the relationship between the hardness and thickness of the rubber elastic layer, the higher the elastic layer is within the above range, the higher the hardness is, and the deviation of the stress balance at the boundary between the rubber elastic layer and the fluororesin layer. It is effective in generating wrinkles and cracks.
[0040]
As the fluororesin (A) of the outermost layer of the composite belt, PTFE, PFA, FEP or the like can be used alone or in combination. At the same time, in order to avoid the offset phenomenon due to the influence of static electricity in electrophotographic technology, it is possible to mix conductive fillers and fillers such as silica in the fluororesin layer to improve the wear resistance of the fluororesin layer. it can.
[0041]
In addition, the fluororesin (B) that is thrown at the boundary surface between the elastic layer and the outermost layer is preferably a PTFE resin that is easily fiberized in an unfired state.
[0042]
The composite belt of the present invention can be manufactured, for example, as follows. First, the polyimide tubular material used as a base layer is obtained by immersing a cylindrical mold in a polyimide precursor solution, attaching the polyimide precursor solution to the mold surface, and then attaching the ring mold (die) from the top of the mold. It is inserted and dropped by its own weight, and is cast (applied) uniformly on the outer peripheral surface of the mold. Thereafter, the mold is heated at 120 ° C. for 40 minutes and at 200 ° C. for 15 minutes to remove the solvent and advance the imide conversion reaction, and then heat-treat from 250 ° C. to 400 ° C. stepwise to perform the imide conversion reaction. Can be completed and removed from the mold after cooling to obtain a tubular product.
[0043]
Further, when the elastic body layer is molded on the polyimide tubular outer layer, the primer liquid is applied to the outer surface of the polyimide tubular member and dried, and then has an outer diameter of the tubular member and a predetermined gap. Using a discharge molding machine having a slit capable of discharging liquid rubber in a direction perpendicular to the surface, the elastic rubber layer can be molded while moving either the tubular product or the discharge molding machine, and then A desired elastic layer can be obtained by vulcanization under conditions.
[0044]
Details of the liquid rubber molding method will be described. The metal mold | die 26 which mounted | wore with the polyimide tubular material is arrange | positioned inside the discharge slit ring 25 of the rubber molding machine 40 shown in FIG. In FIG. 3, 27 is a storage tank, 28 is a slurry pump, 29 is a mixing mixer, 30 and 31 are solenoid valves, 32 is an electric cylinder, 33 is a motor, 34 is a polyimide tube, and 35a to 35c are liquid rubbers. . The liquid rubber 35a previously blended with a filler, a vulcanizing agent, etc. is put into the storage tank 27, and then the drive motor 33 of the slurry pump 28 is moved to pressure-feed the liquid rubber 35a to the static mixer 29. In the static mixer 29, the liquid rubber can be mixed again by turbulent flow of the liquid rubber by the pumping force of the slurry pump. At the same time, the electromagnetic valve 31 is closed, and the liquid rubber 35 b is pumped into the electric cylinder 32. Next, the electromagnetic valve 30 is closed, the electromagnetic valve 31 is opened, and the liquid rubber is branched from the electric cylinder 32 into several circuit pipes by the branching unit 37 and led to the discharge slit ring 25, and the extrusion speed of the electric cylinder 32 and the mold 26 are changed. The rising speed (arrow Y) is controlled, a predetermined amount of mixed varnish is extruded from the discharge slit ring 25, and liquid rubber is applied to the outer surface of the polyimide tubular body with a predetermined thickness.
[0045]
Thereafter, the tubular material that had been inserted into the mold was removed from the rubber molding machine, subjected to primary vulcanization at a temperature of 150 ° C. for 30 minutes, and further post vulcanized at 200 ° C. for 4 hours to form a rubber elastic body layer. A tubular product is obtained. In this liquid rubber molding, liquid rubber can be molded while fixing the discharge slit ring and moving the mold, or the mold is fixed and the discharge slit ring is moved along the outer peripheral surface of the mold You can also. Also, by adding a storage tank, various types of liquid rubber can be pumped and blended or mixed with a static mixer to form a tubular product.
[0046]
In addition, the method of molding liquid rubber on the outer surface of the polyimide tubular body is similar to the method of casting the polyimide precursor solution on the surface of the cylindrical mold, and the liquid rubber is made by running the ring mold (die) by its own weight. Can also be molded. However, in the case of this method, it is difficult to treat the excess liquid rubber scraped off by the ring-shaped mold. Especially, the liquid rubber scraped off once tends to generate bubbles, and the viscosity of the liquid rubber is high. There is also a problem that bubbles are difficult to escape, or a foreign matter is likely to enter the liquid rubber that has been scraped off.
[0047]
In the present invention, the elastic layer and the fluororesin layer are adhered to each other by blasting the rubber surface after the rubber vulcanization of the elastic layer is completed, then impregnating with PTFE resin, drying, wiping, washing, This can be achieved by coating the fluororesin layer used as the outermost layer with a predetermined thickness and firing the fluororesin layer at a temperature of 400 ° C. or higher.
[0048]
【Example】
Hereinafter, it demonstrates more concretely using an Example.
[Measurement method of peel strength (adhesion)]
The adhesion between the rubber elastic body layer and the fluororesin layer of the composite belt was measured by the following method. This adhesion force is measured by fixing a measurement sample to a cylindrical sample mounting jig that can be freely rotated, and using a tensile tester to determine one end of the outermost fluororesin layer having a width of 10 mm in the circumferential direction. It peels at a speed | rate, The peeling force at that time is read from the chart of a testing machine.
[0049]
As will be described later, an adhesive tape is affixed to the surface of the fluororesin layer of the measurement sample, and the adhesive tape is peeled off by a tensile tester. Since the thickness is 20 to 30 μm, the film is stretched and accurate adhesion cannot be measured. Therefore, a method of peeling with an auxiliary tape with a tensile tester is used.
[0050]
FIG. 4 shows an outline of the adhesion measuring device 50. Ball bearings are inserted into both ends of the sample mounting jig 17 in the measuring device 50, so that the mechanism can freely rotate around a mandrel 19 mounted on the support base 18. The frictional force of the sample mounting jig 17 is a minute one that does not cause a problem in this measurement.
[0051]
The sample for measuring the adhesion force is cut from the composite belt in a cylindrical shape with a length of 40 to 50 mm, inserted into the sample mounting jig 17 and fixed at both ends with adhesive tape 21.
[0052]
At the surface of the outermost layer of the sample fixed to the mounting jig, the adhesive tape 22 with a width of 15 mm is pasted around the center in the length direction, and the end of the adhesive tape is cut long so that it can be held by the chuck of the tensile tester. To do. Then, the center part of the sample to which the adhesive tape is attached is cut 10 mm from the top of the adhesive tape with only one outermost fluororesin layer with a one-round knife.
[0053]
At the same time, on the circumference cut to a width of 10 mm, it is attached to the chuck of the tensile tester, so only the fluororesin layer is cut perpendicular to the cut 23 at a portion near the starting point of the adhesive tape cut to the roller. Then, the cut of this part is used as a peeling start point, and the fluororesin layer on the terminal end side of the adhesive tape is peeled off a little in advance and is attached to the adhesive tape. Next, the long cut adhesive tape is gripped by a chuck 24 of a tensile tester, pulled at a speed of 50 mm / min, and the peeling force is continuously recorded on a chart. The average value is the elastic layer of the composite belt and the fluororesin. Let the adhesion of the layer.
[0054]
(Example 1)
(1) Manufacture of polyimide tube
An aluminum mold having an outer diameter of 60 mm and a length of 500 mm was prepared. The outer surface of the mold was polished, and a silicon oxide coating agent was coated on the surface by a dipping method, and then heated and baked to coat the silicon oxide film with a film thickness of 2 μm. The surface of this cylindrical mold had a glass-like mirror surface, and the surface roughness according to JIS-B0601 was (Rz) of 0.5 μm.
[0055]
Next, a 1500 poise polyimide precursor solution (trade name “RC5063 PyreML Varnish” manufactured by IST) was prepared.
[0056]
The mold is immersed in the polyimide precursor solution up to a portion of 400 mm, and after applying the polyimide precursor solution, a ring-shaped outer mold (die) having an inner diameter of 61.6 mm is inserted from above the mold, The polyimide precursor solution having a thickness of 800 μm was cast on the surface of the mold.
[0057]
Then, as a first imide conversion treatment, the mixture was placed in an oven at a temperature of 120 ° C., dried for 60 minutes, heated to 200 ° C. over 40 minutes, and held at the same temperature for 20 minutes. Thereafter, the temperature was raised from 200 ° C. to 400 ° C. over 30 minutes, held at the same temperature for 20 minutes, taken out from the oven, cooled to room temperature, and removed from the mold. In this state, the polyimide tubular product had a thickness of 80 μm, and a completely imidized tubular product having an inner diameter of 60 mm was obtained.
(2) Molding and vulcanization of rubber elastic body
A primer (trade name “X331565” manufactured by Shin-Etsu Chemical Co., Ltd.) was brushed on the polyimide resin tubular product mounted on the mold and dried at room temperature for 30 minutes.
[0058]
Then, the said metal mold | die 26 was arrange | positioned inside the discharge slit ring 25 of the rubber molding machine 40 shown in FIG. A liquid rubber of silicone rubber “KE1379” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and two liquids of silicone rubber “DY356013” (trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.) were mixed in a ratio of 2: 1 in advance and charged into the storage tank 27. .
[0059]
Thereafter, the pump 28 is fed into the tank of the electric cylinder 32 via the mixing mixer 29 to control the extrusion speed of the electric cylinder 32 and the rising speed of the mold 26, and a predetermined amount of mixed liquid silicone rubber is discharged from the discharge slit ring 25. Was extruded, and silicone rubber was applied to the outer surface of the polyimide tube with a thickness of 200 μm.
[0060]
Thereafter, primary vulcanization was performed at a temperature of 150 ° C. for 30 minutes, and further post vulcanization was performed at 200 ° C. for 4 hours, thereby obtaining a tubular product in which silicone rubber was molded to a thickness of 200 μm on the outer layer of the polyimide tubular product. The hardness of the rubber layer was 26 degrees.
(3) Throw-like fluoropolymer treatment and outermost fluoropolymer coating
Next, blasting of the silicone rubber surface (# 100 alumina oxide abrasive, coating pressure 6 kg / cm ² For 10 minutes). After cleaning the silicone rubber surface, use PTFE resin dispersion (DuPont product name “30J”) as the fluororesin (B), soak it for 3 minutes while rotating it, take it out, and take it for 20 minutes at room temperature. Then, the fluorine resin on the surface of the silicone rubber was wiped off with a cloth. By this treatment, the fluororesin (B) fine particles were impregnated in the recesses on the surface of the silicone rubber.
[0061]
Thereafter, as a fluororesin (A), a PTFE resin and a PFA resin were mixed at a ratio of 7: 3, and a fluororesin dispersion (trade name “855-manufactured by DuPont, Inc.) adjusted to a solid content concentration of 45% and a viscosity of 110 centipoise. 510 ″) was immersed in a polyimide / silicone rubber molded tubular article, pulled up at a predetermined speed, coated to a final thickness of 15 μm, dried at room temperature for 30 minutes, and then heated at 230 ° C. for 30 minutes. Thereafter, the tube was passed through a tubular furnace having an inner diameter of 100 mm and the furnace temperature set at 470 ° C. in about 10 minutes, and the fluororesin coated on the silicone rubber surface was baked. Then, after cooling, the tubular material was separated from the mold to obtain the intended composite belt.
[0062]
This composite belt had an inner diameter of 60 mm, a polyimide resin layer of 80 μm, a silicone rubber layer of 200 μm, a fluororesin layer of 15 μm, and a total thickness of 295 μm. A 40 mm length of one end of this belt was cut and used as a measurement sample, and the adhesion was measured based on the adhesion measurement method. The adhesion of this composite belt was 180 g / 10 mm, and the elastic body layer and the fluororesin layer were firmly adhered. Further, when the back surface of the fluororesin layer peeled off from the elastic body layer (boundary surface with the elastic body layer) is observed with a microscope, it becomes fibrous, and the fluororesin (B) cast in the elastic body layer is the fluorine of the outermost layer. It was fused with the resin and adhered in the shape of being pulled out from the elastic layer. Further, when the fused fluororesin layer (A) and fluororesin (B) were peeled from the silicone rubber layer, the silicone rubber layer was separated due to cohesive failure. The state in which the silicone rubber layer was agglomerated and broken and adhered to the fluororesin coating film was clearly observable with the naked eye.
[0063]
This composite belt was mounted on a fixing device of a tandem type color printer and fixed at a speed of 28 sheets / min. As a result, 150,000 sheets of good quality images were obtained.
[0064]
(Comparative Example 1)
Polyimide tubular material and silicone rubber were molded and vulcanized under the same conditions as in Example 1, blasting and PTFE resin impregnation were omitted, and then the outermost fluororesin coating and firing were performed in the same manner as in Example 1. . That is, no recess was formed in the silicone rubber layer, and no fluororesin (B) was embedded.
[0065]
A predetermined sample for measuring the adhesion force was cut out from the composite belt, and the adhesion force was measured to find 30 g / 10 mm. The composite belt was mounted on the printer of Example 1 and a fixing test was conducted. As a result, the outermost fluororesin / silicone rubber interface was floated in several tens of tests, causing wrinkles and cracks.
[0066]
(Example 2)
(1) Preparation of thin metal seamless belt
A stainless steel thin film seamless belt (Endo Manufacturing Co., Ltd.) having a thickness of 48 μm, an inner diameter of 30 mm, and a length of 400 mm was prepared. An iron core was inserted in a state where there was no space on the inner surface of the seamless belt. Using the alumina oxide abrasive grain of mesh number # 230 on the surface of the seamless belt, the pressure is 4 kg / cm. ² And blasted for 3 minutes. Thereafter, it was washed, brushed with a primer, and dried at room temperature for 30 minutes. The uppermost part of the seamless belt was fixed to the core body with a tape, and the seamless belt was arranged inside the discharge slit ring 25 of the rubber molding machine 40 shown in FIG. The inner diameter of the discharge slit ring 25 is 31.2 mm, and silicone rubber “DY387” (trade name, manufactured by Toray Dow Corning Silicon) A and B2 liquids are mixed in a ratio of 1: 1 in advance, and the storage shown in FIG. The tank 27 was charged.
[0067]
Thereafter, the speed of the electric cylinder 32 and the rising speed of the mold were controlled, a predetermined amount of the mixed liquid silicone rubber was extruded from the discharge slit ring 25, and the silicone rubber was applied to the outer surface of the polyimide tubular body with a thickness of 300 μm. Thereafter, primary vulcanization was performed at a temperature of 150 ° C. for 30 minutes, and further post vulcanization was performed at 230 ° C. for 2 hours to obtain a metal thin film seamless belt in which a silicone rubber was formed to a thickness of 300 μm on the outer layer of the polyimide tubular material. The hardness of the rubber layer was 30 degrees.
(2) Throw-like fluoropolymer treatment and outermost fluoropolymer coating
Blasting on the silicone rubber surface (# 100 alumina oxide abrasive, coating pressure 6kg / cm ² For 10 minutes). After cleaning the silicon rubber surface, use PTFE resin dispersion (DuPont brand name “30J”) as fluororesin (B), soak it for 2 minutes while rotating it, take it out, and dry at room temperature for 10 minutes Then, the fluorine resin on the surface of the silicone rubber was wiped off with a cloth. By this treatment, the fluororesin (B) fine particles were impregnated in the recesses on the surface of the silicone rubber.
[0068]
Thereafter, as a fluororesin (A), a PTFE resin and a PFA resin were mixed at a ratio of 7: 3, and a fluororesin dispersion (trade name “855-manufactured by DuPont, Inc.) having a solid content concentration of 45% and a viscosity adjusted to 110 centipoise. 510 "), a metal thin film seamless belt molded with silicon rubber is dipped, pulled up at a constant speed, coated to a final thickness of 15 µm, dried at room temperature for 30 minutes, and then at 230 ° C for 30 minutes. Heated. After that, the tube is passed through a tube furnace having an inner diameter of 50 mm set at a furnace temperature of 560 ° C. in about 3 minutes, the fluororesin coated on the silicone rubber surface is baked, and after cooling, the iron core and the tubular material are separated. The intended composite belt was obtained.
[0069]
The obtained metal composite belt was a metal composite belt having an inner diameter of 30 mm, a metal layer of 48 μm, a silicone rubber layer of 300 μm, a fluororesin layer of 15 μm, and a total thickness of 363 μm. As a result of measuring the adhesion of this belt, it was 230 g / 10 mm, and the elastic layer and the fluororesin layer were firmly adhered. That is, when the fusion-bonded fluororesin layer (A) and fluororesin (B) were peeled from the silicone rubber layer, the silicone rubber layer was separated due to cohesive failure. The state in which the silicone rubber layer was agglomerated and broken and adhered to the fluororesin coating film was clearly observable with the naked eye.
[0070]
This composite belt was mounted on a color printer having a fixing mechanism shown in FIG. 5, and fixing was performed at a speed of 14 sheets / minute.
[0071]
In FIG. 5, a fixing belt support 12 and a ceramic heater 13 are provided inside the fixing belt 11, and a pressure roll 14 press-contacted to the heater surface is used as a drive source, and between the pressure roller 14 and the fixing belt 11. The toner 8 was heated and melted while sequentially feeding the copy paper 7 on which the toner image was formed, and the toner image was heat-fixed on the copy paper at the nip point N. 15 is a thermistor, 16 is a core of a pressure roller, and 9 is a fixed image.
[0072]
【The invention's effect】
As described above, according to the present invention, a recess is formed on the boundary surface between the elastic layer and the fluororesin layer (A) and on the elastic layer side, and the fluororesin (B) is embedded in the recess. Thus, since the fluororesin (B) and the fluororesin layer (A) are fused and integrated, a composite belt having improved adhesion between the elastic body layer and the fluororesin layer can be provided.
[0073]
Further, according to the composite belt manufacturing method of the present invention, the surface of the elastic body layer after vulcanization is sandblasted to form a recess, a solution containing the fluororesin (B) is applied, and the fluororesin is applied to the surface recess By impregnating the particles of (B), coating the fluororesin (A), and then firing at a temperature equal to or higher than the melting point of the fluororesin (A) (B), the fluororesin (B) and the fluororesin layer (A ) Can be fused and integrated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a composite belt according to an embodiment of the present invention.
2 is a schematic enlarged cross-sectional view of a composite belt according to an embodiment of the present invention, in which A is a composite belt using a polyimide tubular base material, and B is an example of a composite belt using a metal tubular base material. FIG.
FIG. 3 is a process conceptual diagram of a rubber molding machine in one embodiment of the present invention.
FIG. 4 is a perspective view showing an adhesion measurement test in one embodiment of the present invention.
FIG. 5 is a cross-sectional view showing a fixing mechanism in Embodiment 2 of the present invention.
FIG. 6 is a cross-sectional view showing a fixing mechanism using a conventional heat fixing roll.
FIG. 7 is a cross-sectional view showing a fixing mechanism using a conventional seamless film.
[Explanation of symbols]
1 Polyimide substrate layer
2 Elastic layer
3 Release layer made of fluororesin (A)
4 Embedded portion made of fluororesin (B)
5 Metal substrate layer
10,11 Composite belt
17 Sample mounting jig
18 Support stand
19 Mandrel
20 Measurement sample
21 Adhesive tape
22 Adhesive tape
23 Cut
24 chuck
25 Discharge slit ring
26 Mold
27 Storage tank
28 Pump
29 Mixing mixer
30, 31 Solenoid valve
32 Electric cylinder
33 motor
35 Liquid rubber
36 Piping
37 Separation unit

Claims (10)

A seamless composite tubular article comprising a tubular base material layer, an elastic body layer, and a fluororesin layer (A) in this order,
A concave portion is formed at the boundary surface between the elastic body layer and the fluororesin layer (A) and on the elastic body layer side,
A composite belt characterized in that a fluororesin (B) is embedded in the recess, and the fluororesin (B) and the fluororesin layer (A) are fused and integrated. 2. The composite belt according to claim 1, wherein the peel strength between the fused fluororesin layer (A) and fluororesin (B) and the elastic layer is 100 g or more in a 1 cm width. 2. The composite belt according to claim 1, wherein when the fusion-bonded fluororesin layer (A) and fluororesin (B) are peeled off from the elastic body layer, the elastic body layer cohesively breaks. The composite belt according to claim 1, wherein the base material layer is at least one selected from a polyimide resin and a metal. The composite belt according to claim 1, wherein the elastic body is at least one selected from silicone rubber and fluororubber. The fluororesin (A) is at least one selected from polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), or The composite belt according to claim 1, wherein the composite belt is a mixture thereof, and the fluororesin (B) is polytetrafluoroethylene (PTFE). 2. The composite belt according to claim 1, wherein the elastic layer has a rubber hardness in a JIS A hardness of 3 to 70 degrees and a thickness of 30 to 1500 μm. A method for producing a seamless composite tubular article comprising a tubular base material layer, an elastic body layer, and a fluororesin layer (A) in this order,
The elastic layer is molded and vulcanized on the outer surface of the base material layer,
The elastic layer surface after vulcanization is sandblasted to form a recess,
Applying a solution containing a fluororesin (B) to the elastic body surface and impregnating the concave portions of the surface with fluororesin (B) particles,
Next, the fluororesin (A) is coated,
Thereafter, the composite belt is manufactured by firing at a temperature equal to or higher than the melting point of the fluororesin (A) (B) and fusing and integrating the fluororesin (B) and the fluororesin layer (A). Method. A method of molding an elastic body layer on the outer surface of the base material layer,
With a discharge molding machine having a predetermined gap with the outer diameter of the tubular substrate, and having a slit for discharging the elastic precursor from the outside to the outer surface of the tubular substrate,
The elastic body precursor is discharged while being controlled at a predetermined speed, and at least one selected from the tubular base material and the discharge molding machine is moved, and an elastic body layer is applied to the outer surface of the base material layer. The manufacturing method of the composite belt of Claim 8 shape | molded with a film thickness. The method for producing a composite belt according to claim 8, wherein the atmosphere temperature is set to 400 ° C. or higher when the fluororesin (A) (B) is fired.

Images