JP2006130822A - Fluorocarbon resin coating method and fixing member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorocarbon resin coating method capable of forming a fluorocarbon resin film which is excellent in adhesion to a silicone rubber layer, thin, and excellent in surface smoothness. <P>SOLUTION: The method includes a first process in which an addition reaction type uncured liquid silicone rubber layer is formed on a substrate, a second process in which thermoplastic resin particles are applied on the surface of the silicone rubber, a third process in which the silicone rubber coated with the resin particles is heated and cured, a fourth process in which the dispersion of fluorocarbon resin particles is applied on the surface of the cured silicone rubber and dried, and a fifth process in which the fluorocarbon resin particles are baked and formed into a film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluororesin coating method on a cylindrical or cylindrical substrate, a laminated member manufactured by this method, and an electrophotographic apparatus such as a copying machine or a laser beam printer (LBP) having the same. The present invention relates to a fixing member provided.

Conventionally, as a fixing device for fixing an unfixed image on a recording material in an image forming apparatus such as an electrophotographic copying machine, a printer, or a fax machine, a contact heating type fixing device having excellent thermal efficiency and safety is widely used. As is known, a belt heating type fixing device that heats through a belt having a small heat capacity is widely used from the viewpoint of energy saving as a method of high heat transfer efficiency and quick start-up of the device. A fixing member is formed by laminating an elastic material or a release material using the belt as a base layer, and energy saving is devised also in these constituent materials. For example, in the surface layer made of a mold release material such as fluororesin, it is desirable that the film thickness is as thin as possible from the viewpoint of thermal efficiency. As a means for realizing this, a fluororesin dispersion or the like is applied on the base layer or the rubber elastic layer. There is a method of forming a film by coating with a spray. However, this method has a problem in that it is difficult to finish a film with good surface smoothness, and therefore, a high-quality image is difficult to obtain, compared to a method of forming a surface layer by covering a tube. Furthermore, there is a problem in durability such as peeling and abrasion of the surface layer due to poor adhesion between the surface layer and the base layer or the elastic layer. As a means for solving these problems, for example, a fluororesin powder obtained by subjecting a silicone rubber before vulcanization to a surface chemical treatment is kneaded and applied onto a core metal, so that fixing with excellent releasability and durability is achieved. There is a prior art of obtaining a roller (Patent Document 1). However, this is because the resin particles are kneaded into the rubber, which increases the hardness and viscosity of the rubber, which degrades the workability and makes it difficult to obtain surface smoothness. Is not enough. To improve the surface smoothness, after forming a silicone rubber elastic layer on the core, laminating a paint in which fluororesin particles are mixed and dispersed in fluororubber, spraying the fluororesin material on the surface and firing There is a manufacturing method of doing this (Patent Document 2), but this is out of the viewpoint of energy saving because the fluoro rubber layer hinders heat conduction. For improving the adhesion between the rubber layer and the resin layer, a technique is known in which the rubber layer is subjected to a treatment such as polishing or blasting to roughen the surface and a resin layer is formed thereon. (Patent Document 3). However, this has a problem that the operation becomes complicated in the manufacturing process.
Japanese Patent Laid-Open No. 07-158632 JP 2000-187407 A JP 09-096987 A

  As described above, when laminating a fluororesin surface layer on a silicone rubber elastic layer, it is necessary to satisfy the adhesive strength between the silicone rubber layer and the fluororesin layer and the surface smoothness of the fluororesin surface layer. is there. Further, it is desirable from the viewpoint of thermal response that the surface layer of the fixing member provided in the electrophotographic apparatus is as thin as possible. However, at present, neither technology is sufficient to satisfy all of these requirements.

  In order to solve the above-mentioned conventional problems, the present invention provides a fluororesin that can form a fluororesin film having a thin film thickness and excellent surface smoothness, with a silicone rubber layer and a fluororesin film having excellent adhesive force. It is an object of the present invention to provide a coating method, a laminated member obtained by this method, and a fixing member having the laminated member.

  In order to achieve the above object, the first invention according to the present application is the minimum necessary for the main object of the present invention, and as a first step, uncured addition-reactive liquid silicone rubber is formed on a substrate. Forming a layer, applying thermoplastic resin particles to the surface of the silicone rubber as a second step, heat-curing the silicone rubber coated with the thermoplastic resin particles as a third step, and By providing and drying a dispersion of fluororesin particles on the surface of the heat-cured silicone rubber, and providing the fluororesin coating method characterized by firing and forming the fluororesin particles as a fifth step, It is possible to obtain a thin fluororesin film having excellent surface smoothness and to obtain a good adhesive force between the fluororesin film and the silicone rubber layer.

  In order to achieve the above object, a second invention according to the present application is an invention relating to the thermoplastic resin particles in the first invention, wherein the thermoplastic resin particles are a fluorine resin powder subjected to a defluorination treatment. It is characterized by being. By using the fluorine resin powder that has been defluorinated, it is possible to secure a wide contact area between the fluorine resin powder, the fluorine resin film, and the silicone rubber layer, and to exert a chemical bonding force. Adhesive performance (durability) can be provided.

  3rd invention which concerns on this application is invention about the composition of the silicone rubber of 1st or 2nd invention, addition reaction type liquid silicone rubber is the number of moles of hydrogen atoms of the siloxane bond before vulcanization, By compounding the molar ratio of vinyl groups (H / Vi) in the range of 1.0 to 5, it is easier to demonstrate the chemical bonding force between the fluororesin powder that has been defluorinated and the silicone rubber. The purpose is to do.

  4th invention based on this application is invention regarding the particle diameter and covering area occupation rate of the thermoplastic resin particle of 1st-3rd invention, While using particle | grains whose particle diameter is 0.1 micrometer or more and 15 micrometers or less, By making the covering area occupation ratio of the lower layer silicone rubber 70% or more and less than 100%, it becomes possible to achieve both the surface smoothness of the fluororesin film and the adhesive force between the fluororesin film and the silicone rubber layer, It is an object to more effectively achieve the main object of the present invention. Here, the particle diameter means an average particle diameter, and the average particle diameter indicates a median diameter (D50) measured with a laser diffraction particle size distribution analyzer (trade name: SALD-7000, manufactured by Shimadzu Corporation). . Further, the covering area occupancy is a range of 10 mm × 10 mm in any five places of the thermoplastic resin particles applied to the silicone rubber, and the thermoplastic resin particles viewed from the direction of the thermoplastic resin particles applied in the thermoplastic rubber particle application direction. Expressed as the average of the ratio of the total coverage area. Specifically, the surface to which the thermoplastic resin particles before heat-curing were adhered was observed from the application direction with a high-magnification video microscope (trade name Digital HF Microscope VH-8000, manufactured by KEYENCE Inc.), and the observed image was binarized. The covering area occupation ratio with respect to the silicone rubber layer of the thermoplastic resin particles was calculated. Similarly, the average value of five locations observed and calculated was defined as the covering area occupation ratio of the member.

  The fifth and sixth inventions according to the present application are inventions relating to laminated members formed using the fluororesin coating methods of the first to fourth inventions, and a cured layer of an addition reaction type liquid silicone rubber and a fluororesin An object of the present invention is to achieve the main object of the present invention by laminating the fired layer of particles through a fluorine resin powder subjected to defluorination treatment.

  The seventh and eighth inventions according to the present application are inventions concerning a fixing member formed using the laminated members of the fifth and sixth inventions, and the laminated members of the fifth and sixth inventions on a substrate. It is an object of the present invention to achieve the main object of the present invention.

  According to the present invention described above, there is provided a fluororesin coating method capable of securing a good adhesive force between the fluororesin film and the silicone rubber layer while forming a thin fluororesin film having excellent surface smoothness. can do.

  Further, by using this method, it is possible to provide a fixing member disposed in an electrophotographic apparatus that is excellent in surface smoothness and durability.

  Hereinafter, an example of an embodiment in which the present invention is implemented is shown using the drawings.

  FIG. 1 shows a laminated member that can be formed by using the fluororesin coating method of the present invention. 11 is a surface layer made of fluorine resin, 12 is thermoplastic resin particles (fluorine resin powder subjected to defluorination treatment), and 13 is an elastic layer made of silicone rubber.

  In the fluororesin coating method of the present invention, the thermoplastic resin particles used are preferably fluororesin powder that has been defluorinated from the viewpoint of adhesive performance. The particle diameter of the fluororesin powder is preferably 0.1 μm or more and 15 μm or less. This is because it is advantageous in forming a film with good smoothness while reducing the film thickness in film formation. Furthermore, it is preferable that the covering area occupation ratio with respect to the silicone rubber of the said fluororesin powder is 70% or more and less than 100%. This is because it is advantageous in terms of securing a wide contact area between the fluororesin powder, the silicone rubber elastic layer, and the fluororesin surface layer, and forming a film having good surface properties. The type of silicone rubber used is not particularly limited as a form of the crosslinking reaction, but in order to make the silicone rubber as thin as possible and to ensure a wide contact area with the fluororesin powder, a liquid addition reaction is used. A mold is preferably used.

  Further, various types of functional groups are known for silicone rubber, but silicone rubbers having these known types of functional groups may be used. In particular, dimethyl silicone rubber having only a methyl group, and methyl phenyl silicone rubber / phenyl silicone rubber having a phenyl group are well known and preferably used for toner fixing members.

  The silicone rubber may be blended with an inorganic powder filler for the purpose of heat resistance, heat transfer, reinforcement, increase in weight, and the like. Known inorganic fillers can be used. Examples thereof include crystalline silica, fumed silica, iron oxide, and alumina. Preferably, these inorganic fillers are used by blending 0.1 to 100 parts by weight with respect to 100 parts by weight of silicone rubber.

  In addition, a compounding agent may be added to the silicone rubber for adjusting various properties.

  The addition reaction type liquid silicone rubber is preferably blended in a ratio of the number of moles of hydrogen atoms of the siloxane bond before vulcanization and the number of moles of vinyl group (H / Vi) in the range of 1.0 to 5. . This is to make it easier to exhibit the effect of chemical adhesion with the fluororesin powder that has been defluorinated while maintaining rubber elasticity as a silicone rubber. Moreover, the kind of fluororesin powder used can use a known kind of material, and is not specifically limited. Generally well-known, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE) It is preferable to use a single type or a composite type of fluororesin powder such as polyfluorinated ethylene chloride (CTFE) polyvinylidene fluoride.

  The present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention.

Example 1
First, as a first step, an addition reaction type two-component liquid silicone rubber raw material was prepared. This was applied on the cylindrical core so that the film thickness was uniform. Thereafter, PTFE powder was prepared as thermoplastic resin particles in the second step, and this was subjected to defluorination treatment. As the defluorination treatment method, a chemical treatment method using a tetrahydrofuran solution of a metal sodium-naphthalene complex was adopted. Specifically, the PTFE powder is immersed in a tetrahydrofuran solution of metal sodium-naphthalene complex (trade name: Tetra Etch A, manufactured by Junkosha Co., Ltd.) which has been returned to room temperature for about 5 to 10 seconds, and then the PTFE powder is ethanol, water, acetone. Washed in order. As described above, the PTFE powder subjected to the defluorination treatment was applied to the surface of the silicone rubber. At this time, the covering area occupation ratio of the fluororesin powder was 70% or more and less than 100% with respect to the lower layer silicone rubber. Covering area occupancy was observed after the application with a high-power video microscope, and after confirming that the covering area occupancy could be controlled as intended, the fluororesin powder was applied as a third step. Silicone rubber was heat-cured at 200 ° C. for 4 hours, and as a fourth step, a fluororesin dispersion liquid (trade name: NEOFLON PFA product number; AD-2CR, manufactured by Daikin Industries, Ltd.) was prepared. This was applied to the surface of the heat-cured silicone rubber and dried, and as a fifth step, the fluororesin particles were heated from room temperature to 370 ° C. over one hour, and then heated and fired.

  A method for producing a laminated member obtained by using the fluororesin coating method as described above will be described with reference to FIG. This laminated member is mainly used as a fixing member disposed in an electrophotographic apparatus such as a copying machine or a laser beam printer (LBP).

  As the base layer, an endless belt made of SUS having an outer diameter of 70 mm and a thickness of 30 μm was prepared. This belt is inserted into an aluminum hollow core and mounted on a workpiece rotating jig, and a primer for silicone (manufactured by Toray Dow Corning Silicone Co., Ltd.) is attached to the belt surface where the workpiece is rotated at a constant speed in the belt circumferential direction. Product name DY39-051) was thinly coated and heat-treated in a warm air oven at 200 ° C. for 1 hour. After cooling, the liquid silicone rubber raw material (trade name DY35-561 manufactured by Toray Dow Corning Silicone Co., Ltd.) is adjusted on the belt surface so that H / Vi = 1 before vulcanization, and the film thickness becomes 300 μm. Was applied uniformly. Next, a fluorine resin powder that had been defluorinated by a chemical treatment method was applied to the silicone rubber applied to the belt by electrostatic coating. As the fluororesin powder, PTFE powder having an average particle size (including aggregated particles) of about 5 μm (trade name: Lubron product number: L-5F, manufactured by Daikin Industries, Ltd.) was used. The paint gun containing PTFE powder (product name: ANEST IWATA Co., Ltd., trade name: powder electrostatic gun, product number: PCH-85) is moved at a constant speed in the long axis direction while maintaining the distance from the belt at 15 cm. However, the PTFE powder was electrostatically coated on the surface of the belt inserted into an aluminum hollow core and mounted on a workpiece rotating jig, and the workpiece was rotated at a constant speed in the belt circumferential direction. The covering area occupation ratio was adjusted by the work rotation speed, the coating gun discharge amount, the applied voltage, and the gun moving speed. For example, in order to control the covering area occupation ratio to 70%, after preheating the belt, the work rotation speed, the discharge amount of the coating gun, and the applied voltage were adjusted. When the above-mentioned PTFE powder was spray-coated by the above-described method, the belt surface was observed with a high magnification video microscope, and it was confirmed that the covering area occupation ratio could be controlled to 70% as intended. The amount of fluororesin powder and the height protruding from the silicone rubber surface are similarly adjusted by the workpiece rotation speed, coating gun discharge amount, applied voltage, gun movement speed, etc. It was confirmed by observation that the height from the rubber surface was about half of the particle diameter. The observation was performed from the cross-sectional direction of the rubber after coating with a high magnification video microscope. After confirming that the covering area occupancy and the height of the PTFE powder from the silicone rubber could be controlled as intended, the silicone rubber coated with the PTFE powder was heated and cured at 200 ° C. for 4 hours and released to room temperature. After cooling, the above-mentioned PFA dispersion liquid was spray-coated as a fluororesin material for forming the surface layer. The spray coating method uses a paint spray gun (trade name: Automatic gun part number: WA-100-101P, manufactured by Anest Iwata Co., Ltd.), and is made of aluminum while moving the gun at a constant speed in the long axis direction. The PFA dispersion liquid was sprayed onto the belt surface that was inserted into the air core and mounted on a workpiece rotating jig, and the workpiece was rotated at a constant speed in the belt circumferential direction. By adjusting the work rotation speed, the discharge amount of the spray gun and the atomization pressure, the thickness of the surface layer after heating and firing was adjusted to fall within the range of 15 μm to 20 μm. The film thickness was controlled by managing the weight after spray coating. A belt formed by laminating silicone rubber, fluororesin powder, and fluororesin dispersion liquid in this order was placed in an oven and baked from room temperature to 370 ° C. for 1 hour.

(Example 2)
A fixing member was produced in the same manner as in Example 1, except that the liquid silicone rubber raw material used in Example 1 was changed to H / Vi before vulcanization so that H / Vi = 5. .

(Example 3)
The fixing member was fixed in the same manner as in Example 1 except that the liquid silicone rubber raw material used in Example 1 was changed to H / Vi before vulcanization so that H / Vi = 0.5. Produced.

Example 4
PTFE powder (Asahi ICC Fluoropolymers Co., Ltd.) having an average particle diameter of about 25 μm as the average particle diameter of PTFE powder (trade name: Lubron product number; L-5F, manufactured by Daikin Industries, Ltd.) used in Example 1 A fixing member was produced in the same manner as in Example 1 except that the product number was changed to G190).

(Example 5)
Fixing is performed in the same manner as in Example 1 except that the covering area occupancy of the PTFE powder used in Example 1 (trade name: Lubron product number; L-5F, manufactured by Daikin Industries, Ltd.) is changed to 95%. A member was prepared.

(Example 6)
Fixing is performed in the same manner as in Example 1 except that the covering area occupancy of the PTFE powder used in Example 1 (trade name: Lubron product number; L-5F, manufactured by Daikin Industries, Ltd.) is changed to 50%. A member was prepared.

(Example 7)
A fixing member was produced in the same manner as in Example 1 except that the PTFE powder used in Example 1 (trade name: Lubron product number; L-5F, manufactured by Daikin Industries, Ltd.) was used without performing defluorination treatment. .

(Comparative Example 1)
The PTFE powder used in Example 1 (trade name: Lubron product number; L-5F, manufactured by Daikin Industries, Ltd.) and a water-based paint composed of a mixture of fluororubber and fluororesin (trade name: Daiel Latex, product name, manufactured by Daikin Industries, Ltd.) GLS-213). In this case, the production method of the fluororesin coating method and the laminated member / fixing member made using the same was changed as follows. First, the liquid silicone rubber used as an elastic layer was applied on a cylindrical core, vulcanized at 200 ° C. for 4 hours, and allowed to cool to room temperature. Thereafter, the latex was spray-coated on the vulcanized silicone rubber surface to a thickness of 25 μm. The silicone rubber coated with the latex was heated and cured at 200 ° C. for 30 minutes and then allowed to cool to room temperature. Thereafter, a fluororesin dispersion liquid as a surface layer was spray-coated on the latex-coated surface.

  A fixing member was produced in the same manner as in Example 1 except for the above changes.

  Table 1 shows Examples 1 to 7 and Comparative Example 1 studied as described above.

[Performance evaluation-Heat fixing device-]
In order to evaluate the performance of the above examples and comparative examples, a fixing device as shown in FIG. 2 was prepared. FIG. 2 shows an example of a heat-fixing device that has evaluated the performance of the present invention. The heat-fixing device 200 is a belt heating type device using a ceramic heater as a heating element, and the fixing belt 210 is the one according to the present invention described above. is there.

  The belt guide 216c is a heat and heat insulating belt guide. The ceramic heater 212 as a heating body is fixedly supported by being fitted into a groove formed along the longitudinal direction of the guide at substantially the center of the lower surface of the belt guide 216c. The cylindrical or endless fixing belt 210 of the present invention is loosely fitted on the belt guide 216c.

  The pressurizing rigid stay 222 is inserted inside the belt guide 216c.

  The pressure member 230 is an elastic pressure roller in this example. The pressure member 230 is formed by providing an elastic layer 230b of silicone rubber or the like on the core metal 230a to reduce the hardness. The both ends of the core metal 230a are connected to the front and rear chassis side plates (not shown) of the apparatus. The bearing is rotatably held between them. In order to improve the surface properties, the elastic pressure roller further has PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer) on the outer periphery. A fluororesin layer such as a polymer may be provided.

  By pressing the pressure springs (not shown) between the both ends of the pressure rigid stay 222 and the spring receiving member (not shown) on the apparatus chassis side, a pressing force is applied to the pressure component stay 222. ing. As a result, the lower surface of the sliding plate 240 disposed on the lower surface of the belt guide member 216a and the upper surface of the pressure roller 230 are pressed against each other with the fixing belt 210 interposed therebetween to form a fixing nip portion N having a predetermined width. As the belt guide member 216, a resin having excellent heat resistance such as a heat resistant phenol resin, an LCP (liquid crystal polyester) resin, a PPS (polyphenylene sulfide) resin, or a PEEK (polyether ether ketone) resin is used.

  The pressure roller 230 is driven to rotate counterclockwise as indicated by an arrow by the driving means M. A rotational force acts on the fixing belt 210 by a frictional force between the pressure roller 230 and the outer surface of the fixing belt 210 by the rotational driving of the pressure roller 230, and the inner surface of the fixing belt 210 is a ceramic heater in the fixing nip portion N. While rotating in close contact with the lower surface of 212, it rotates outwardly of the belt guide 216c in a clockwise direction as indicated by an arrow at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 230 (pressure roller drive system). .

  In this embodiment, a pressure roller having an outer diameter of 20 mm is used.

  Based on the print start signal, rotation of the pressure roller 230 is started, and heat-up of the ceramic heater 312 is started. When the rotation peripheral speed of the fixing belt 210 is stabilized by the rotation of the pressure roller 230 and the temperature of the ceramic heater 212 has risen to a predetermined temperature, there is a gap between the fixing belt 210 and the pressure roller 230 in the fixing nip N. A recording material P carrying a toner image t as a heating material is introduced with the toner image carrying surface side facing the fixing belt 210 side. The recording material P is in close contact with the lower surface of the ceramic heater 212 via the fixing belt 210 in the fixing nip portion N, and moves and passes through the fixing nip portion N together with the fixing belt 210. In the moving and passing process, the heat of the ceramic heater 212 is applied to the recording material P via the fixing belt 210, and the toner image t is heated and fixed on the surface of the recording material P. The recording material P that has passed through the fixing nip N is separated from the outer surface of the fixing belt 210 and conveyed.

  The ceramic heater 212 as a heating body is a horizontally long linear heating body having a low heat capacity and having a longitudinal direction in a direction orthogonal to the moving direction of the fixing belt 210 and the recording material P. A heater substrate 212a made of aluminum nitride or the like, and a heating layer 212b provided on the surface of the heater substrate 212a along the length thereof, for example, an electric resistance material such as Ag / Pd (silver / palladium) is about 10 μm, width 1 The heat generating layer 212b provided by coating by ~ 5 mm by screen printing or the like, and a protective layer 212c made of glass or fluororesin, etc. provided thereon are the basic components. The ceramic heater to be used is not limited to this.

  And by supplying with electricity between the both ends of the heat_generation | fever layer 212b of the ceramic heater 212, the heat_generation | fever layer 212b will generate | occur | produce heat and the heater 212 will heat up rapidly. The heater temperature is detected by a temperature sensor (not shown), and energization of the heat generating layer 12b is controlled by a control circuit (not shown) so that the heater temperature is maintained at a predetermined temperature, and the heater 212 is temperature-controlled. .

  The ceramic heater 212 is fixedly supported by fitting the protective layer 212c upward in a groove formed along the longitudinal direction of the guide at the substantially central portion of the lower surface of the belt guide 216c. The surface of the sliding member 240 of the ceramic heater 212 and the inner surface of the fixing belt 210 slide in contact with each other at the fixing nip portion N in contact with the fixing belt 210. The nip width is changed according to the process speed in order to secure the nip residence time of the recording paper.

[Evaluation of performance-Evaluation method and results-]
The evaluation method of the fixed image is that the unfixed toner image (cyan / magenta two-color solid image M / S = 1.2) is obtained by fixing the fixing belt of each of the examples and comparative examples incorporated in FIG. Then, the gloss of the toner-fixed image after passing the paper was evaluated as the initial gloss. The gloss was evaluated by sensory evaluation in order to determine with high sensitivity the extremely high-quality toner image that is the object of the present invention. First, with regard to the glossiness of the image, in order to give universality to the evaluation, a standard sample image was prepared and the evaluation criteria were matched. That is, three sample images having gloss values of 30, 40, and 50 (when using an IG-320 incident angle of 60 ° manufactured by Horiba, Ltd.) were prepared. This was prepared by placing cyan / magenta toner on an aluminum sheet, which is a smooth surface, so that the toner amount per unit area (mg / cm ² ) was 1.2, and hot pressing under various conditions. . After showing these three sample images to several subjects and recognizing that “the glossiness is sufficient”, regarding the initial gloss of the two-color solid image in which the present invention was implemented, “O = Glossy” ”,“ △ = less glossiness ”, and“ × = no glossiness ”. The process conditions were set such that the nip inner surface pressure = 1 kgf / cm ² , the fixing belt surface temperature = 160 ° C., and the fixing belt rotation speed = 80 rpm (rotation / min). The above evaluation results were used as indicators of the thermal responsiveness and surface smoothness of the surface layer.

For the idling test and its evaluation, a heat fixing device as shown in FIG. 2 was used as the fixing device. The fixing member prepared in each of the examples and comparative examples was attached thereto, and an idling test was performed without passing paper up to 500 hours. As each process condition, nip inner surface pressure = 1 kgf / cm ² , fixing belt surface temperature = 210 ° C., fixing belt rotation speed = 80 rpm (rotation / minute). The surface condition of the fixing member is visually confirmed every 100 hours. K. At the time when the level and peeling were confirmed, it was considered as adhesive peeling. The above evaluation results were used as an index of adhesion between the surface layer and the elastic layer.

  The results of Examples 1 to 7 and Comparative Example 1 evaluated by the above method are shown in Table 2 below.

[Example 1]
Both the initial gloss and the surface properties of the belt surface layer after 500 hours of idling were good results. This indicates that the surface layer of the member is thin, the surface thereof is smooth, and the adhesive force between the surface layer and the elastic layer is excellent.

  Therefore, it was possible to provide a fixing member excellent in thermal responsiveness and surface smoothness while ensuring the adhesion between the elastic layer and the surface layer.

[Example 2]
Good results were obtained in both initial gloss and durability.

  Therefore, it was possible to provide a fixing member excellent in thermal responsiveness and surface smoothness without impairing the adhesion between the elastic layer and the surface layer.

[Example 3]
Although good results were obtained in the initial gloss, peeling of the surface layer was observed in 480 hours before reaching 500 hours in the idling durability test. This is considered to be because the H / Vi ratio of the silicone rubber of the elastic layer was small, but it is a level that does not cause any problem when used as a fixing member.

[Example 4]
Good results were obtained in durability, but the initial gloss was slightly inferior. This is considered to be because the particle size of the fluororesin particles is too large, which adversely affects the surface smoothness of the fluororesin film. However, this is a level that does not cause a problem when used as a fixing member.

[Example 5]
Good results were obtained in both initial gloss and durability.

  Therefore, it was possible to provide a fixing member excellent in thermal responsiveness and surface smoothness without impairing the adhesion between the elastic layer and the surface layer.

[Example 6]
Although good results were obtained in the initial gloss, peeling of the surface layer was observed in 480 hours before reaching 500 hours in the idling durability test. This is thought to be due to the small coverage of the fluororesin particles, but at a level that does not pose a problem when used as a fixing member.

[Example 7]
In the initial gloss, good results were obtained, but in the idling durability test, peeling of the surface layer was observed in 450 hours before reaching 500 hours. This is thought to be because the surface treatment was not performed on the fluororesin particles, but it is at a level that does not cause a problem when used as a fixing member.

[Comparative Example 2]
The initial gloss was worse than that of the above example. This is thought to be because the latex layer interposed between the silicone rubber and the surface fluoropolymer hinders heat transfer. This is a level that is difficult to use as a fixing member.

An example of embodiment which implemented this invention. 1 is an example of a heat fixing apparatus for evaluating the performance of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Surface layer 12 Thermoplastic resin particle 13 Elastic layer 200 Heat fixing apparatus 210 Fixing belt 212 Ceramic heater 216C Belt guide 222 Rigid stay for pressure 230 Pressure member (pressure roller)
240 Sliding plate N Fixing nip t Toner image P Recording material

Claims (8)

  An uncured layer of addition reaction type liquid silicone rubber is formed on a substrate as a first step, thermoplastic resin particles are applied to the surface of the silicone rubber as a second step, and the thermoplastic resin as a third step. The silicone rubber coated with particles is heat-cured, and a dispersion of fluorine resin particles is applied and dried on the surface of the heat-cured silicone rubber as a fourth step, and the fluorine resin particles are baked as a fifth step. A fluororesin coating method characterized by forming a film.   2. The fluororesin coating method according to claim 1, wherein the thermoplastic resin particles are fluororesin powder subjected to defluorination treatment.   The addition reaction type liquid silicone rubber is characterized in that the ratio of the number of moles of hydrogen atoms of siloxane bonds before vulcanization and the number of moles of vinyl groups (H / Vi) is in the range of 1.0 to 5. The fluororesin coating method according to claim 1 or 2.   The fluororesin powder has a particle size of 0.1 µm or more and 15 µm or less, and a covering area occupancy with respect to a lower layer of silicone rubber is 70% or more and less than 100%. Fluororesin coating method.   A laminated member, wherein a cured layer of an addition reaction type liquid silicone rubber and a fired layer of fluorine resin particles are laminated via thermoplastic resin particles.   6. The laminated member according to claim 5, wherein the thermoplastic resin particles are a fluorine resin powder subjected to a defluorination treatment.   A fixing member comprising the laminated member according to claim 5 on a base material.   A fixing member comprising the laminated member according to claim 6 on a base material.

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