JP2009109998A - Heat generation fixing roll and image fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe image fixing device activation capable of performing quick start in a very short standby time from the power activation, keeping power consumption low, and achieving a high speed of full-color image fixing. <P>SOLUTION: A heat generation fixing roll includes a core body, an elastic layer, and a heat generating tubular body. The elastic layer is formed on an outer peripheral face of the core body. The heat generating tubular body is formed on an outer peripheral side of the elastic layer. In addition, the heat generating tubular body has at least a resistive heat generating body layer, an insulating layer, a mold release layer, and a conductive electrode layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image fixing device of an image forming apparatus such as a copying machine or a laser beam printer. The present invention also relates to a heat fixing roll incorporated in the image fixing apparatus.

  Conventionally, in an image forming apparatus such as a copying machine or a laser beam printer, a heat roller method is often used as a method for thermally fixing an unfixed toner image formed on a sheet-like transfer material such as copy paper or OHP in an image forming unit. Has been. However, in recent years, the film fixing method shown in FIG. 8 has become mainstream from the viewpoint of energy saving.

  In the film fixing type image forming apparatus 70, a seamless fixing belt is used in which a release layer such as a fluororesin is laminated on the outer surface of a heat resistant film such as polyimide. One example will be described with reference to FIG.

  In the film fixing type image forming apparatus 70, a belt guide 72 and a ceramic heater 73 are disposed inside the fixing belt 71, and a pressure roll 74 and a fixing belt 71 that are pressed against the ceramic heater 73 via the fixing belt 71. In between, the copy paper 77 on which the unfixed toner image 78 is formed is sequentially fed, and the toner is heated and melted and thermally fixed on the copy paper. In such an image forming apparatus 70, the toner is substantially directly heated by the ceramic heater 73 through the fixing belt 71 in the form of a very thin film. Therefore, the contact surface N (nip surface) between the fixing belt 71 and the pressure roll 74. Reaches a predetermined fixing temperature instantly. Therefore, such an image forming apparatus 70 has a short waiting time from when the power is turned on until it reaches a fixable state, and also has low power consumption. For this reason, such an image forming apparatus 70 is widely used from home use to industrial use. In FIG. 8, reference numeral 75 denotes a thermistor, reference numeral 79 denotes a fixed toner image, and reference numeral 76 denotes a cored bar portion of the pressure roll 74.

By the way, in such a conventional film fixing type image forming apparatus, as described above, the fixing belt is heated via the ceramic heater, and the toner image is fixed on the surface thereof. It becomes an important point. However, if the fixing belt is made thin to improve the thermal conductivity, there is a problem that the mechanical characteristics are lowered and it is difficult to increase the speed, and the ceramic heater is easily damaged. In order to solve such a problem, in recent years, a method has been proposed in which a heating element is provided on the fixing belt itself and the fixing belt is directly heated by supplying power to the heating element to fix the toner image (for example, (See Patent Documents 1 to 4). This type of image forming apparatus has an even shorter waiting time from when the power is turned on until it reaches a fixable state, further reducing power consumption, and is excellent in terms of speeding up thermal fixing.
JP 2000-066539 A JP-A-10-142972 JP 2000-058228 A Japanese Patent Laid-Open No. 5-188809

  However, many problems still remain in such a new type image forming apparatus, and such a new type image forming apparatus has not yet been put into practical use.

  For example, the belt heater system described in the above patent document has the following problems. In this application, in describing the fixing method of the electrophotographic image forming process, the fixing method shown in FIG. 8 is the “film fixing method”, the fixing method described in the above patent document is the “belt heater method”, and the method of the present application is described. This is described as “heat generation roll method”.

  In the belt heater type fixing belt heater, a heat generating layer is formed by mixing a conductive material such as carbon powder or metal powder with a heat-resistant insulating base material such as polyimide or silicone rubber. For this reason, it is difficult to obtain a heating element having a uniform heating region. Patent Document 3 discloses a thin film resistance heating element formed mainly from carbon nanotubes and a carbon microphone coil as a heating element material, and a toner heat fixing member using the thin film resistance heating element. Yes. However, when the heating element material is formed only of carbon nanotubes or carbon microcoils, increasing the mixing amount of carbon nanotubes or the like in order to reduce the volume resistivity, the mechanical characteristics of the heating element are drastically reduced. There is a problem and it is very difficult to produce a heating resistor having a low volume resistivity.

  Patent Document 1 describes forming a fixing belt heater by a centrifugal molding method. However, such a molding method has a problem that it is difficult to mass-produce a fixing belt having a small inner diameter (10 to 20 mm), and cannot cope with a reduction in cost of a laser beam printer or the like.

  Furthermore, Patent Document 4 describes that a heating element is mixed in a heat-resistant and insulating polyimide or polyamide-imide resin substrate and formed into a cylindrical heating roll by a method such as injection molding. However, in such a heat generating roll, the roll itself does not have elasticity (softness), and the nip surface with the pressure roll becomes narrow, so that it is difficult to sufficiently heat the unfixed toner image, and it is not possible to cope with high speed. There is also a problem in fixing a color image in which four color toners are sufficiently melted and mixed at the nip surface.

  The present invention has been made in view of the above-described problems. The standby time after power-on is very short, a quick start can be performed, power consumption can be kept low, and high-speed fixing can be performed. An object of the present invention is to provide an image fixing device having high performance.

  The heat fixing roll according to the first invention includes a core body, an elastic layer, and a heat generating tubular body. The elastic layer is formed on the outer peripheral surface of the core body. The heat generating tubular body is formed on the outer peripheral side of the elastic layer. The heating tubular body has at least a resistance heating element layer, an insulating layer, a release layer, and a conductive electrode layer.

  The exothermic fixing roll according to the second invention is the exothermic fixing roll according to the first invention, and the elastic layer has a hardness of 3 degrees or more and less than 60 degrees.

  A heat generating fixing roll according to a third aspect of the present invention is the heat generating fixing roll according to the first aspect or the second aspect of the present invention, wherein the elastic layer is a foam. Such an elastic foam is, for example, sponge rubber.

  A heat generating fixing roll according to a fourth aspect of the present invention is the heat generating fixing roll according to any one of the first to third aspects of the present invention, wherein the resistance heating element layer is made of a polyimide resin in which carbon nanomaterials and filamentary metal particles are dispersed. Become.

  An exothermic fixing roll according to a fifth invention is the exothermic fixing roll according to the fourth invention, wherein the carbon nanomaterial is at least one conductive material selected from the group consisting of carbon nanofibers, carbon nanotubes, and carbon microcoils. It is.

  A heat-generating fixing roll according to a sixth aspect of the present invention is the heat-generating fixing roll according to the fourth aspect or the fifth aspect of the present invention, and the filamentary metal particles are nickel particles having a shape in which strands are three-dimensionally connected. The filamentary nickel particles preferably have a shape as shown in FIG. This is because filamentary nickel particles are entangled with carbon nanofibers and the like, and the resistance of the resistance heating element layer is reduced.

  A heat generating fixing roll according to a seventh aspect of the present invention is the heat generating fixing roll according to any one of the fourth to sixth aspects, wherein the carbon nanomaterial and the filamentous metal particles are oriented substantially in one direction.

  An exothermic fixing roll according to an eighth aspect is the exothermic fixing roll according to the seventh aspect, wherein the carbon nanomaterial and the filamentous metal particles are oriented in the length direction. The volume resistivity in the length direction is smaller than the volume resistivity in the direction orthogonal to the length direction.

  A heat-generating fixing roll according to a ninth invention is the heat-fixing roll according to any of the fourth to eighth inventions, wherein the polyimide resin comprises at least one aromatic diamine and at least one aromatic tetracarboxylic acid. A polyimide resin obtained by imidizing a polyimide precursor obtained by polymerizing dianhydride in an organic polar solvent.

  An exothermic fixing roll according to a tenth invention is the exothermic fixing roll according to any of the first to ninth inventions, wherein the insulating layer comprises at least one aromatic diamine and at least one aromatic tetracarboxylic acid. A polyimide precursor obtained by polymerizing a dianhydride in an organic polar solvent comprises a polyimide resin obtained by imide conversion.

  An exothermic fixing roll according to an eleventh invention is the exothermic fixing roll according to the ninth or tenth invention, wherein the aromatic diamine is paraphenylenediamine (PPD). The aromatic tetracarboxylic dianhydride is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA).

  An image fixing apparatus according to a twelfth aspect includes a heat generating fixing roll and a power feeding means. The heat fixing roll is a heat fixing roll according to any one of the first to eleventh aspects. The power supply means is for supplying power to the heat generating fixing roll.

  In the heat fixing roll according to the present invention, an elastic layer is formed on the outer peripheral surface of the core, and a heat generating tubular layer is formed on the outer peripheral side of the elastic layer. For this reason, this heat generating fixing roll has flexibility. Therefore, when the pressure roll is brought into pressure contact with the heat generating fixing roll, the nip width can be widened. For this reason, if this heat fixing roll is incorporated in an image forming apparatus, it is possible to fix at high speed, improve the image quality of a full-color image, and speed up color fixing. Further, when the elastic layer is a foam, a heat insulating effect can be enjoyed, and the amount of heat of the resistance heating element layer can be efficiently used for image fixing.

  Further, when the matrix resin and the insulating layer of the resistance heating element layer are polyimide resins, the heat fixing roll can be continuously used even in a high temperature range of 180 to 250 degrees C which is a fixing temperature range. In addition, if the conductive material mixed in the resistance heating element layer is oriented in a certain direction, variation in volume resistivity can be reduced, and a desired volume resistance can be achieved with a small amount of mixed conductive material. Rate can be obtained. Further, by changing the mixing ratio of the carbon nanomaterial and the filamentary nickel particles, it is possible to design a heat-generating fixing roll having a high volume resistivity in a wide range.

  In the image fixing apparatus according to the present invention, the heat generating fixing roll itself generates heat by directly supplying power to the resistance heating element layer of the heat generating fixing roll without requiring a special ceramic heater or the like as in the prior art. For this reason, this image fixing apparatus has high thermal efficiency, and there is no waiting time after the power is turned on, and a quick start can be performed.

  Next, embodiments of the present invention will be described in detail.

  FIG. 1A is a schematic longitudinal sectional view of a heat-generating fixing roll according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line II of the heat-generating fixing roll. 2A is an external perspective view of the heat-generating fixing roll according to the embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line II-II of the heat-generating fixing roll.

  As shown in FIGS. 1 and 2, the heat fixing roll 10 according to an embodiment of the present invention mainly includes a first insulating layer 1, a resistance heating element layer 2, a second insulating layer 3, and a release layer 4. , Electrode layer 5, elastic layer 6 and roll core 7. Hereinafter, the first insulating layer 1, the resistance heating element layer 2, the second insulating layer 3, the release layer 4, and the electrode layer 5 may be collectively referred to as “heating tube layer” or “heating tube body”. Hereinafter, the roll mandrel 7 and the elastic layer 6 may be collectively referred to as a “heat generating tubular layer support roll”.

  Both the matrix resin of the resistance heating element layer 2 and the resin forming the insulating layers 1 and 3 are polyimide resins. By adopting such a configuration, a power supply terminal (for example, a power supply roller or an electrode brush) can be brought into contact with the resistance heating element layer 2 inside the heat fixing roll 10, and as a result, power is supplied to the resistance heating element layer 2. Can do. For this reason, the resistance heating element layer 2 can generate heat.

  The electrode layer 5 is for supplying power to the resistance heating element layer 2 and is provided at both ends of the outermost layer of the heat-generating fixing roll 10. When the power supply terminal comes into contact with the electrode layer 5 and power is supplied to the electrode layer 5, the heat generating fixing roll 10 generates heat.

  In the heat fixing roll 10, the first insulating layer 1 is formed on the innermost side of the heat generating tubular layer that is in contact with the elastic layer 6, and the resistance heating element layer 2 is formed on the outer side of the first insulating layer 1. The second insulating layer 3 and the release layer 4 are formed outside the resistance heating element layer 2 except for the electrode layer 5. When such a configuration is adopted, the thermal conductivity of the first insulating layer 1 is not related to the fixing conditions, and the thickness of the insulating layers 1 and 3 is determined only for the purpose of satisfying sufficient mechanical characteristics of the heat generating tubular layer. be able to. Since only the thin second insulating layer 3 and the release layer 4 exist outside the resistance heating element layer 2 in this manner, it is preferable from the viewpoint of quick start or energy saving. In addition, in order to obtain composite properties such as thermal conductivity, mechanical properties, and releasability, a function can be added to the heat-generating fixing roll 10 by multilayering the heat-generating tubular layer as necessary. The electrode layer 5 may be formed by applying a conductive ink, a conductive paste, or the like, or may be formed by bonding a metal foil, a metal net, or the like.

  In the present embodiment, the resin forming the matrix resin and the insulating layers 1 and 3 in the resistance heating element layer 2 of the heat fixing roll 10 are all polyimide resins. Therefore, even if the resistance heating element layer 2 and the insulating layers 1 and 3 are thin films, they have sufficient mechanical characteristics and rigidity. Polyimide resin has the highest heat resistance, insulation and safety among plastic materials.

  Further, the heat-generating fixing roll 10 according to an embodiment of the present invention preferably has an outer diameter of 10 mm to 70 mm for use in a laser beam printer, and has an outer diameter of 30 mm to 120 mm for use in high-speed fixing such as a copying machine. Are preferably used.

  Next, in the exothermic fixing roll 10 according to an embodiment of the present invention, the exothermic tubular layer support roll is not particularly limited as long as it has a heat resistance of 150 ° C. to 250 ° C. which is a necessary temperature for image fixing. It is not something. Silicone rubber is the most preferred material for the elastic layer 6 in terms of heat resistance and processability. The exothermic tubular layer support roll is basically formed by roughening the outer surface of an aluminum or iron roll core 7 by blasting or the like, and then forming an elastic layer 6 such as silicone rubber on the outer peripheral surface thereof. can get. The elastic layer 6 is preferably a solid rubber layer or a sponge rubber layer formed by foaming silicone rubber to provide a heat insulating effect.

  In a heat fixing roll 10 according to an embodiment of the present invention, a resistance heating element layer 2 is formed on the outside of a heat generating tubular layer support roll via a first insulating layer 1. For this reason, the elastic layer 6 is preferably formed of a material having a low heat capacity, a low thermal conductivity, and a high heat insulating effect. This is because it is advantageous for quick start and thermal efficiency of the image fixing apparatus.

  The solid rubber layer made of silicone rubber has a thermal conductivity of 0.20 to 0.30 W / (m · k), and the sponge rubber is 0.10 to 0.15 W / (m · k). If there is, heat insulation effect can be increased to about twice that of solid rubber. The hardness of the elastic layer 6 is preferably 3 degrees or more and less than 60 degrees. More preferably, it is 5 degrees or more and less than 50 degrees. More preferably, it is the range of 30 degrees or more and less than 50 degrees. This is because, when the hardness is such, when the pressure roll is brought into pressure contact with the heat-generating fixing roll 10, the nip area between the two rolls can be designed widely.

  The selection of the thermal conductivity and hardness of the elastic layer 6 can be performed based on specifications such as the processing speed of the image fixing device and the outer diameter of the heat-generating fixing roll 10. Further, when the elastic layer 6 is too thin, the metal roll core 7 loses heat, so that the elastic layer 6 needs an appropriate thickness, but the thickness is 3 mm to 10 mm. Preferably there is. Further, it is preferable to mix a hollow glass, silica, alumina, or other filler in the elastic layer 6 in order to improve the heat insulating properties.

In the embodiment of the present invention, in the resistance heating element layer 2 of the heat-fixing roll 10, the carbon nanomaterial and the filamentous metal fine particles are substantially uniformly dispersed in the matrix resin made of polyimide resin. . The carbon nanomaterial is preferably at least one conductive substance selected from the group consisting of carbon nanofibers, carbon nanotubes, and carbon microcoils. Such a carbon nanomaterial has a fiber diameter of several nm to several hundred nm, a fiber length of several μm to several tens of μm, and a bulk density of 0.01 to 0.3 g / cm ³ . The specific surface area is 10 to 100 m ² / g. Among these, carbon nanofibers are particularly preferable conductive materials, and those having a fiber diameter of 20 to 200 nm and a fiber length of 0.1 to 10 μm are particularly preferable. It is because it is easy to disperse | distribute uniformly to a polyimide precursor solution, and to make it orientate to a substantially one direction.

  Further, in the embodiment of the present invention, as described above, it is an essential condition that the resistance heating element layer 2 contains filamentous metal fine particles together with the carbon nanomaterial. Image fixing devices such as laser beam printers require the ability to thermally fix an unfixed toner image on A4 size paper at a rate of 30 to 40 sheets per minute, so the fixing unit generates 500 to 1000 W of heat. This is because a uniform heat generation surface is required. Note that it is difficult to control such heat generation characteristics only with the carbon nanomaterial. This is because in order to obtain a low electrical resistance of several ohms by mixing only carbon nanomaterials, it is necessary to mix a large amount of carbon nanomaterials with the solid content of the polyimide precursor. This is because the mechanical characteristics of the resistance heating element layer 2 are remarkably deteriorated. Therefore, in order to achieve both the calorific value necessary for such characteristics and sufficient mechanical characteristics, it is essential to include filamentous metal fine particles having higher conductivity than the carbon nanomaterial together with the carbon nanomaterial. .

Examples of the filamentous metal fine particles include acicular crystal silver particles, aluminum particles, and nickel particles. In addition, nickel fine particles having a shape in which strands are three-dimensionally connected are more preferable. The nickel fine particles have an average particle diameter of 0.1 to 5.0 μm, a specific surface area of 1.0 to 100 m ² / g, and have a shape in which strands are three-dimensionally connected as shown in the photograph of FIG. This is because a low resistance heating element can be formed by being entangled with the carbon nanomaterial linearly, and the resistance heating element layer 2 having a uniform volume resistivity can be formed. When the metal fine particles mixed with the carbon nanomaterial are granular, powdery, or massive, the metal fine particles are not entangled with the carbon nanomaterial and are in point contact, so that the uniform resistance heating element layer 2 is produced. Is difficult. In addition, when the metal fine particles and the carbon nanomaterial are in point-like contact, extremely fine sparks are easily generated during energization, and the life of the resistance heating element layer 2 is significantly reduced.

  In the embodiment of the present invention, it is preferable that the conductive substance in the resistance heating element layer 2 is oriented in a certain direction. The carbon nanomaterial used in the embodiment of the present invention has a fiber diameter of 20 to 200 nm and a fiber length of 0.1 to 10 μm. When these carbon nanomaterials are simply mixed in a polyimide precursor solution and cast on a glass plate, the vertical and horizontal directions vary. And when a polyimide precursor is imide-converted in this state, there exists a problem that the dispersion | variation in the resistance value of the film formed becomes large. Further, it is necessary to mix more carbon nanomaterials compared to the case where the carbon nanomaterials are oriented, which inevitably leads to a decrease in mechanical properties of the resistance heating element layer 2.

  Therefore, it is preferable that these carbon nanomaterials are oriented substantially in one direction, that is, the individual fibers of the carbon nanomaterial are bundled in the length direction. This is because the electrical resistance value can be lowered with a small amount of carbon nanomaterial mixed, and uniform heat generation characteristics can be obtained.

  Various shapes and particle sizes of graphite, carbon black, carbon nanotubes, carbon microcoils, metal particles such as nickel powder and silver powder, metal alloy particles such as stainless steel powder, tungsten carbide, tantalum carbide, boron for the purpose of improving conductive properties Non-conductive such as alumina, boron nitride, aluminum nitride, silicon carbide, titanium oxide, silica, etc. for the purpose of improving the thermal conductivity of conductive particles such as intermetallic compounds such as tungsten fluoride and metal-coated powders such as silver-coated carbon For the purpose of improving mechanical properties, etc., the particles are fibrous particles such as potassium titanate fiber, acicular titanium oxide, aluminum borate whisker, tetrapotted zinc oxide whisker, sepiolite, glass fiber, and viscosity minerals such as montmorillonite and talc. Can be added to the extent that the original purpose is not impaired. Other surfactants, antifoaming agents, dispersing agents, coupling agents such as silane coupling agents, metal scavengers such as thiol compounds, imidazoles, etc. for the purpose of improving coatability and dispersibility, mechanical properties, etc. Such an imidizing agent may be added to such an extent that the original purpose is not impaired.

  As shown in FIG. 7, a conductive composition 64 containing a polyimide precursor is applied to the outer surface of a cylindrical mold 61, and a ring-shaped die 62 is run outside the cylindrical mold 61 to conduct the conductive composition. When the conductive composition coating 63 of the object 64 is formed on the outer surface of the cylindrical mold 61, the carbon nanomaterial in the conductive composition coating 63 is substantially unidirectional toward the traveling direction of the ring-shaped die 62. And aligned. Thereafter, the conductive composition coating 63 is dried and the imidization of the polyimide precursor is completed, whereby the most preferred resistance heating element solidified in a state in which the carbon nanomaterial is oriented as shown in the photograph of FIG. Layer 2 can be shaped. In addition, the carbon nanomaterial 81 of the photograph of FIG. 6 is a carbon nanofiber. In addition, as can be seen from the photograph of FIG. 6, the filamentous metal fine particles 82 mixed with the carbon nanomaterial are entangled with the carbon nanomaterial and are arranged in the orientation direction of the carbon nanomaterial. Layer 2 is in the most preferred state. As the filamentous metal fine particles, nickel fine particles having a shape in which strands are three-dimensionally connected are used.

  In the embodiment of the present invention, the conductive substance in the resistance heating element layer 2 is present in the length direction of the heat-generating fixing roll 10, and the volume resistivity in this orientation direction is orthogonal to this orientation direction. It is preferably smaller than the volume resistivity in the direction. As a result of repeated experiments on the relationship between the orientation direction of the conductive material and the volume resistivity, the present inventors have found that the volume resistivity in the orientation direction of the conductive material is different from the volume resistivity in the direction intersecting this direction. I found out. That is, when the volume resistivity in the orientation direction of the conductive material is LD and the volume resistivity in the direction orthogonal to the orientation direction is DD, the ratio Ra (= DD / LD) may be twice or more. all right.

  As described above, the conductive material is uniformly oriented in a certain direction as the value of Ra is larger. Accordingly, in forming the desired resistance heating element layer 2, the amount of the conductive material mixed may be smaller as the orientation becomes more uniform. In this way, the volume resistivity can be finely adjusted by uniformly orienting the carbon nanomaterial and mixing the carbon nanomaterial and the filamentous metal fine particles, and the mechanical properties of the resistance heating element layer 2 are reduced. The heat-generating fixing roll 10 having a uniform volume resistivity and excellent durability can be obtained without causing the above.

  Moreover, in preferable embodiment of this invention, it is preferable that the abundance of the carbon nanomaterial and filament-like metal microparticles | fine-particles in the resistance heating element layer 2 is 5-50 vol% with respect to a polyimide solid content. More preferably, it is the range of 10-40 vol%. If the abundance is less than 5 vol%, the volume resistivity varies greatly and it is difficult to obtain a uniform heat generation region. On the other hand, when the abundance is 50 vol% or more, the mechanical properties and durability of the resistance heating element layer 2 are lowered, which is not preferable. Moreover, the mixing ratio of the carbon nanomaterial and the filamentous metal fine particles can be arbitrarily selected depending on the volume resistivity of the resistance heating element layer 2 and a desired amount of heat generation. Since the heat generation amount in the heat fixing roll 10 is in the range of 500 to 1500 W, the heat generation amount is adjusted according to the specifications such as the outer diameter of the heat fixing roll 10 and the thickness and length of the heat generation tubular layer (copy paper size A4 or A3). can do.

  In the embodiment of the present invention, the resin forming the matrix resin and the insulating layers 1 and 3 of the resistance heating element layer 2 is composed of at least one aromatic diamine and at least one aromatic tetracarboxylic dianhydride. The polyimide precursor obtained by polymerization in a polar solvent is preferably composed of a polyimide resin obtained by imide conversion.

  Representative examples of aromatic diamines include paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'- Dimethyl-4,4′-biphenyl, 3,3′-dimethoxy-4,4′-biphenyl, 2,2-bis (trifluoromethyl) -4,4′-diaminobiphenyl, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane (MDA), 2,2-bis- (4-aminophenyl) propane, 3,3′-diaminodiphenylsulfone (33DDS), 4,4′-diaminodiphenylsulfone (44DDS), 3 , 3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ether 3,4′-diaminodiphenyl ether (34 ODA), 4,4′-diaminodiphenyl ether (ODA), 1,5-diaminonaphthalene, 4,4′-diaminodiphenyldiethylsilane, 4,4′-diaminodiphenylsilane, 4, , 4′-diaminodiphenylethylphosphine oxide, 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-aminophenoxy) benzene (134APB), 1,4-bis (4- Aminophenoxy) benzene, bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- (4- Aminophenoxy) phenyl] propane (BAPP), 2,2-bis (3-aminopheny ) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) 1,1,1,3,3,3-hexafluoropropane and 9,9-bis ( 4-aminophenyl) fluorene and the like. Among them, preferable diamines are paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 4,4′-diaminodiphenylmethane (MDA), 3,3′-diaminodiphenylsulfone (33DDS), and 4,4′-diaminodiphenylsulfone. (44DDS), 3,4'-diaminodiphenyl ether (34 ODA), 4,4'-diaminodiphenyl ether (ODA), 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4- Aminophenoxy) benzene (134APB), bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- (4-Aminophenoxy) phenyl] propane (BAP ) It is.

  Moreover, as a typical example of aromatic tetracarboxylic dianhydride, pyromellitic dianhydride (PMDA), 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8- Naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3′4 ′ -Biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2', 3,3'-benzophenone tetracarboxylic acid dihydrate, 2, 3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride (BTDA), bis (3,4-dicarboxyphenyl) sulfone dianhydride Bis (2,3- Carboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3 4-dicarboxyphenyl) ethane dianhydride, 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride , Oxydiphthalic anhydride (ODPA), bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfoxide dianhydride, thiodiphthalic dianhydride, 3,4, 9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthre Tetracarboxylic dianhydride, 9,9-bis (3,4-dicarboxyphenyl) fluorene dianhydride and 9,9-bis [4- (3,4'-dicarboxyphenoxy) phenyl] fluorene dianhydride Etc. Among them, preferred tetracarboxylic dianhydrides are pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-. Examples include benzophenone tetracarboxylic dianhydride (BTDA), 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), and oxydiphthalic anhydride (ODPA). These may be reacted with alcohols such as methanol and ethanol to form ester compounds.

  In addition, these aromatic diamine and aromatic tetracarboxylic dianhydride can be used individually or in mixture. Moreover, multiple types of polyimide precursor solutions can be prepared and these polyimide precursor solutions can be mixed and used.

  Organic polar solvents for reacting aromatic tetracarboxylic dianhydrides with aromatic diamines include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, hexamethylphosphoric triamide, 1,2-dimethoxyethane, diglyme and triglyme. Among them, preferred solvents are N, N-dimethylacetamide (DMAC) and N-methyl-2-pyrrolidone (NMP). These solvents can be used alone or as a mixture or mixed with other solvents such as toluene, xylene, that is, aromatic hydrocarbons.

  In the embodiment of the present invention, the aromatic diamine is paraphenylene diamine, and the aromatic tetracarboxylic dianhydride is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. Particularly preferred. Polyimide resins obtained from these monomers are excellent in mechanical properties and tough, and do not soften or melt like thermoplastic resins even when the temperature of the resistance heating element layer 2 rises, and have excellent heat resistance It is because it has.

  Such a polyimide precursor solution is obtained by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine in an organic polar solvent usually at 90 ° C. or lower. In addition, the solid content concentration in the solvent can be appropriately adjusted depending on the mixing ratio of the conductive substance or the coating conditions. The preferable range is 10-30 mass%.

  In addition, when aromatic tetracarboxylic dianhydride and aromatic diamine are reacted in an organic polar solvent, the viscosity of the solution increases depending on the polymerization state. Can be used from. It is usually used at a viscosity of 1 to 5000 poise depending on manufacturing conditions and working conditions.

  In order to apply the conductive composition to the surface of the mold by a casting method so that the conductive substance is oriented in approximately one direction, the viscosity of the conductive composition may be in the range of 10 to 1500 poise. preferable. More preferably, it is the range of 50-1000 poise. When the second insulating layer 3 is provided in the heat-generating fixing roll 10 according to the embodiment of the present invention, the second insulating layer 3 includes boron nitride, potassium titanate, titanium oxide, aluminum nitride, alumina, silicon carbide, It is preferable that a thermally conductive material having electrical insulation properties such as silicon nitride is mixed. This is because thermal conductivity can be imparted and a uniform heating surface can be obtained. The viscosity of the insulating polyimide precursor solution for forming the second insulating layer 3 is also preferably 50 to 1000 poise.

  In the embodiment of the present invention, the release layer 4 of the heat fixing roll 10 is made of polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoro. There is preferably at least one resin selected from the group consisting of propylene copolymers (FEP).

  The release layer 4 made of a fluororesin is preferably 5 to 30 μm thick, and more preferably 10 to 20 μm thick. Further, it is preferable to apply a primer between the second insulating layer 3 and the release layer 4 in order to stabilize the adhesiveness. Moreover, it is preferable that the thickness of the primer layer is 2-5 micrometers.

  The thickness of the resistance heating element layer 2 of the heat-generating fixing roll 10 necessary for obtaining a desired amount of heat generated by electricity is set based on factors such as the amount of conductive material mixed, the inner diameter of the heat-generating fixing roll 10, or the contact width of the power supply terminal. be able to.

  Moreover, the thickness of the 1st insulating layer 1 is a thickness required in order to ensure the mechanical characteristic of the resistance heating element layer 2, Comprising: It is preferable that they are 20 micrometers-80 micrometers. The second insulating layer 3 is formed outside the resistance heating element layer 2. In order to efficiently conduct the amount of heat generated from the resistance heating element layer 2 to the outermost layer (the surface directly in contact with the toner image) of the heat fixing roll 10, the second insulating layer 3 is preferably as thin as 5 μm. It is preferably ˜50 μm. A thickness of 10 μm to 20 μm is more preferable. Further, if the thickness is optimized after mixing the second insulating layer 3 with a heat conductive material such as boron nitride, the second insulating layer 3 satisfies both the insulating properties, mechanical properties, and thermal conductivity properties. be able to.

  Alternatively, the resistance heating element layer 2 may be in direct contact with the surface of the heating tube layer support roll without providing the first insulating layer 1. This is because a heat-generating fixing roll can be provided at a lower cost.

  In addition, the heat fixing roll 10 according to an embodiment of the present invention includes a process for manufacturing a heat generating tubular body (hereinafter referred to as “heat generating tubular body manufacturing process”) and a process of forming a heat generating tubular layer support roll inside the heat generating tubular body. (Hereinafter, referred to as “heat generation tubular layer support roll forming step”).

  The exothermic tubular body manufacturing step includes (a) a step of applying a polyimide precursor solution that is a raw material of the first insulating layer 1 to the outer surface of the cylindrical mold, and (b) heating the applied polyimide precursor solution to the first. A step of forming the insulating layer 1, (c) a step of applying a conductive composition in which a carbon nanomaterial and a filamentous metal fine powder are mixed in a polyimide precursor solution to the outer surface of the first insulating layer 1, and (d) coating. A step of forming the resistance heating element layer 2 by heating the conductive composition formed, and (e) a second insulating layer 3 on the outer surface of the resistance heating element layer 2 except for electrode forming portions at both ends of the resistance heating element layer 2. A step of applying an insulating polyimide precursor solution, (f) a step of heating the insulating polyimide precursor solution to form the second insulating layer 3, and (g) conductive at both ends where the second insulating layer 3 is not formed. Forming the electrode layer 5 with a conductive paste or the like (h Comprising the step of step of applying to the outer surface excluding the electrode layer 5 a release layer 4, and (j) a release layer 4 and heating the baking.

  In the embodiment of the present invention, after the conductive composition is applied to the outer surface of the cylindrical mold, the carbon nanomaterial and the filamentous metal fine particles in the conductive composition are substantially unidirectional, that is, the length thereof. In order to orient in a state of being bundled in a direction, it is preferable to provide a step of wiping the coated surface in a certain direction after coating the conductive composition on the cylindrical mold.

  In order to orient the conductive composition in substantially one direction, in the step (a), as shown in FIG. 7, the conductive composition 64 is applied to the outer surface of the cylindrical mold 61 to form a ring shape. Most preferably, the die 62 is inserted from the upper side of the cylindrical mold 61 and the ring-shaped die 62 is passed through the outside of the cylindrical mold 61. This is because the control of the coating thickness of the conductive composition 64 and the orientation of the conductive substance can be processed in one step. In addition, in FIG. 7, the code | symbol 63 is the electrically conductive composition coating film apply | coated by fixed thickness.

  Moreover, in the said manufacturing method, after apply | coating the electrically conductive composition 64 to the outer surface of the cylindrical metal mold | die 61 at the (a) process, the polyimide precursor in the electrically conductive composition 64 apply | coated at the (b) process is obtained. It is preferable to be heated so as to be in a semi-cured state. Furthermore, in step (c), an insulating polyimide precursor solution is applied to the outer surface of the semi-cured resistance heating element layer 2 and then in step (d). The insulating polyimide precursor solution is preferably heated to complete imidization of the polyimide precursor in the resistance heating element layer 2 and the polyimide precursor in the insulating layers 1 and 3 simultaneously. By imidizing the polyimide precursor in the resistance heating element layer 2 and the polyimide precursor in the insulating layers 1 and 3, the resistance heating element layer 2 and the insulating layers 1 and 3 can be firmly bonded, and This is because the thermal efficiency of the production line can be increased.

  Furthermore, also in the step (e) and the step (f) of forming the release layer 4 on the outer surface of the second insulating layer 3, the polyimide precursor in the resistance heating element layer 2 and the polyimide precursor in the insulating layers 1 and 3. Each body is in a semi-cured state, a fluororesin dispersion or the like is applied to the outer surface, and after drying, the polyimide precursor in the resistance heating element layer 2 and the insulating layers 1 and 3 is completely imidated and separated. It is preferable that the fluororesin in the mold layer 4 is fired simultaneously. This is because the adhesive strength of each layer can be increased. In addition, since the imidization temperature of the polyimide precursor and the firing temperature of the fluororesin are both treated at a high temperature of 350 ° C. to 400 ° C., each heat treatment step can be shortened by treating these simultaneously. And increase the thermal efficiency during production. When the release layer 4 is formed on the outer surface of the second insulating layer 3, it is preferable to interpose a primer layer in order to stabilize the adhesive strength.

  The semi-cured state refers to a state where the conductive composition or the insulating polyimide precursor solution is dried at a temperature of 80 to 120 ° C. and then heated at a temperature of 200 to 250 ° C. In such a case, the polyimide precursor is in a state before imidization is completed. Further, the processing time required to reach this state is 30 minutes to 2 hours.

  In the exothermic tubular layer support roll forming step, after the roll core 7 is inserted into the inner surface of the exothermic tubular body, an elastic body material such as liquid silicone is cast, and the exothermic constant according to one embodiment of the present invention is determined. A roll 10 is manufactured. Further, after the heat generating tubular layer support roll whose elastic layer 6 is sponge rubber or the like is manufactured, the heat generating tubular layer support roll is inserted into the heat generating tubular body to manufacture the heat generating constant roll 10 according to one embodiment of the present invention. You can also

  Next, an embodiment of an image fixing apparatus incorporating the heat fixing roll 10 according to an embodiment of the present invention will be described with reference to FIG. In FIG. 3, the image fixing device 30 mainly includes a heat-generating fixing roll 10, a pressure roll 36, and a power supply roll 33. The pressure roll 36 is pressed against the heat fixing roll 10, and as a result, a nip portion N is formed between the pressure roll 36 and the heat fixing roll 10. When the transfer paper 39 on which the unfixed toner image 38 is formed is inserted into the nip portion N, the toner image 38 is thermally fixed on the transfer paper 39.

  A driving source for rotating the heat fixing roll 10 may be provided in either the pressure roll 36 or the heat fixing roll 10. When the heat fixing roll 10 is driven by the pressure roll 36, the heat fixing roll 10 is driven by the pressure contact force of the nip portion N. As described above, when the driving source is connected only to the pressure roll 36, when the transfer paper 39 is inserted into the nip portion N and the unfixed toner image 38 is fixed on the transfer paper 39, the transfer paper 39 passes through the transfer paper 39. Since the heat-generating fixing roll 10 needs to be driven and rotated, a minute slip may be accompanied depending on the type of the transfer sheet 39 at the time of speeding up. In order to prevent such a minute slip, it is preferable to accurately transmit the rotational power from the pressure roll 36 to the heat fixing roll 10 via a gear or the like.

  A pair of electrode layers 5 for supplying power to the heat-generating fixing roll 10 are provided at both ends of the heat-generating fixing roll 10, and power is supplied from the power supply roll 33 that contacts while rotating on the surface of the heat-generating fixing roll 10. The resistance heating element layer 2 generates heat. Although control of the fixing temperature is not shown, temperature control is performed based on temperature information obtained from a thermistor brought into contact with the surface of the heat generating constant fixing roll 10.

  In FIG. 3A, reference numeral 42 is a power source, reference numeral 35 is a core metal of a pressure roll, and reference numeral 43 is a lead wire. FIG. 1B is a cross-sectional view taken along the line III-III in FIG.

  In the image fixing device 30 according to the embodiment of the present invention, since both the heat-generating fixing roll 10 and the pressure roll 36 have the elastic layer 6, the nip portion N can be designed widely, high-speed fixing, Or, it is excellent in fixing and speeding up full-color images.

  Examples are shown below. In addition, evaluation of the implementation product was performed on the conditions shown below using the measuring device shown below.

(1) Measurement of volume resistivity Using a digital multimeter Model 7562 (manufactured by Yokogawa Electric), the volume resistivity of the exothermic tubular layer was measured with a four-wire probe.

(2) Measurement of temperature distribution The temperature distribution of the exothermic tubular layer at the time of heat generation was measured with a thermotracer TH1101 (manufactured by NEC Sanei).

  In this example, after the heat-generating fixing roll 10 having the structure shown in FIG. 1 was manufactured as shown below, the heat-generating characteristics and fixability of the heat-generating fixing roll were evaluated. First, the heat generation tubular body was manufactured.

<Production of exothermic tubular body>
(1) Production of Conductive Composition for Resistance Heating Element Layer A polyimide precursor solution (polyimide varnish “Pyre-ML RC5063”, manufactured by IS Corporation) was prepared. This polyimide precursor solution is obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride “BPDA” and paraphenylenediamine “PPD” in N-methyl-2-pyrrolidone (NMP). The solid content concentration was 17.5 wt%. And in this polyimide precursor solution, 20 vol% carbon nanofibers (VGCF-H, manufactured by Showa Denko) and 13 vol% filamentary nickel fine particles (TYPE210, manufactured by Inco) with respect to the solid content of the polyimide precursor solution, Was added and stirred for 1 hour, and then the mixture was filtered through No. 150 SUS mesh to prepare a conductive composition for a resistance heating element layer having a viscosity (23 degrees C, measured by B type viscometer) 800 poise. did. The true density of the carbon nanofiber (VGCF-H) is 2.0 g / cm ³ , and the true density of the filamentary nickel fine particles (TYPE 210) is 8.9 g / cm ³ .

(2) Production of Polyimide Precursor Solution for First Insulating Layer A polyimide varnish “Pyre-ML RC5063” (manufactured by IST Co.) was prepared as a polyimide precursor solution for forming the first insulating layer. The polyimide precursor solution had a solid content concentration of 17.5 wt% and a viscosity (according to a 23-degree C, B-type viscometer) of 850 poise. Hereinafter, this polyimide precursor solution is referred to as “a polyimide precursor solution for the first insulating layer”.

(3) Preparation of Polyimide Precursor Solution for Second Insulating Layer A polyimide varnish “Pyre-ML RC5063” (manufactured by IS Co., Ltd.) was prepared as a polyimide precursor solution for forming the second insulating layer. Then, boron nitride powder (Mitsui Chemical "MBN-010T") is mixed with the polyimide precursor solution at 20 wt% with respect to the solid content concentration of the polyimide precursor solution to prepare a polyimide precursor solution for the second insulating layer. did. This polyimide precursor solution for the second insulating layer was prepared so that the viscosity of a B-type viscometer at 23 ° C. was 880 poise.

(4) Molding of first insulating layer After coating the surface of an aluminum cylindrical mold having an outer diameter of 24 mm and a length of 500 mm with a silicon oxide coating agent by dipping, the aluminum cylindrical mold is fired. Thus, the aluminum cylindrical mold was covered with the silicon oxide film. The average surface roughness of this cylindrical mold was Rz 0.2 μm. Next, as shown in FIG. 7, an aluminum cylindrical mold is immersed in a first insulating layer polyimide precursor solution from the bottom to a 400 mm portion, and the first insulating layer polyimide precursor is immersed in the aluminum cylindrical mold. After applying the solution, a ring-shaped die is inserted and run from the upper side of the aluminum cylindrical mold, and the first insulating layer cast is placed outside the aluminum cylindrical mold so that the thickness after imide conversion is 70 μm. A film was formed.

  Thereafter, the aluminum cylindrical mold on which the first insulating layer cast film is formed is placed in an oven at 120 ° C. and dried for 60 minutes, and then heated to a temperature of 200 ° C. over 30 minutes. And then removed from the oven and allowed to cool to room temperature (25 degrees C). As a result, a semi-cured first insulating layer belt was obtained.

(5) Formation of Resistance Heating Element Layer Next, as shown in FIG. 7, the aluminum cylindrical mold formed with the semi-cured first insulating layer belt is immersed in the resistance heating element layer conductive composition. Then, the conductive composition for the resistance heating element layer was cast on a cylindrical aluminum die with a ring die so that the thickness after imide conversion was 35 μm. Next, in the same manner as in the heat treatment of item (4), this aluminum cylindrical mold was placed in an oven at 120 ° C. and dried for 60 minutes, and then heated to a temperature of 200 ° C. over 30 minutes. After holding for 15 minutes, it was removed from the oven. As a result, a semi-cured conductive layer laminated belt in which a semi-cured conductive layer was laminated on the outer surface of the first insulating layer was obtained.

(6) Molding of second insulating layer Next, after masking the electrode layer formation scheduled portions at both ends of the semi-cured conductive layer laminated belt, the semi-cured conductive layer laminated belt is molded as shown in FIG. The aluminum cylindrical mold is immersed in the polyimide precursor solution for the second insulating layer and pulled up, and then the aluminum cylindrical mold is placed on the aluminum cylindrical mold with a ring die so that the thickness after imidization becomes 15 μm. The polyimide precursor solution for the second insulating layer was cast. Next, the aluminum cylindrical mold was placed in an oven at 120 ° C. and dried for 60 minutes in the same manner as in the heat treatment of item (5), and then heated up to a temperature of 200 ° C. over 30 minutes. After holding for 15 minutes, it was removed from the oven. As a result, a semi-cured second insulating layer laminated belt in which a second insulating layer made of a semi-cured polyimide precursor was laminated on the outer surface of the semi-cured conductive layer was obtained.

(7) Molding of fluororesin primer layer After removing the mask from the semi-cured second insulating layer laminated belt, masking the electrode layer formation scheduled portion again, and then forming the semi-cured second insulating layer laminated belt, the aluminum cylindrical gold The mold was immersed in a fluororesin primer solution, and then the aluminum cylindrical mold was pulled up at a predetermined speed to coat the fluororesin primer solution to a thickness of about 4 μm. Then, the aluminum cylindrical mold was dried at a temperature of 150 ° C. for 20 minutes and cooled to room temperature again to obtain a primer molding belt.

(8) Molding of Release Layer Next, PTFE dispersion (manufactured by DuPont: “Teflon (registered trademark)” 855-510) was prepared as a material for forming the release layer. After masking only the lower part of the primer molding belt to which the fluororesin primer liquid was applied, the aluminum cylindrical mold on which the primer molding belt was molded was immersed in PTFE dispersion to the position where the primer layer was applied. Then, the PTFE dispersion was coated to a thickness of 15 μm by pulling up the aluminum cylindrical mold at a predetermined speed to obtain a fluororesin-coated belt. Thereafter, the masking is removed from the fluororesin-coated belt, the fluororesin-coated belt is dried at 200 ° C. for 10 minutes, heated to 400 ° C. over 30 minutes, and heated at the same temperature for 20 minutes to thereby remove the PTFE resin. Firing and imidation of the semi-cured polyimide precursor in the resistance heating element layer, the first insulating layer, and the second insulating layer were completed at the same time to obtain a release layer laminated belt. The configuration of the release layer laminated belt is as shown in FIG. The inner diameter of the heat generating tubular body is 30 mm, the thickness of the first insulating layer is about 70 μm, the thickness of the resistance heating element layer is about 35 μm, the thickness of the second insulating layer is about 15 μm, The release layer had a thickness of about 15 μm and a total thickness of 140 μm.

(9) Formation of Conductive Paste Thin Film Electrode Next, after forming a conductive paste (Toyobo Co., Ltd. DWP-025) to a thickness of 30 μm on the resistance heating element layer exposed portions at both ends of the release layer laminated belt, The conductive paste was heated in a drying furnace at 120 ° C. for 30 minutes and 200 ° C. for 30 minutes to form a conductive paste thin film electrode on the release layer laminated belt, thereby obtaining a desired exothermic tubular body.

<Production of heat fixing roll>
The surface of an aluminum hollow core metal having an outer diameter of 12 mm for the bearing portion and an outer diameter of 20 mm for the portion forming the elastic layer was roughened by blasting. Next, a primer was applied to the outer surface of the hollow metal core. Thereafter, the exothermic tubular body and the hollow core metal are mounted on a casting mold in a state where the hollow core metal is inserted into the exothermic tubular body, and a silicone rubber precursor is interposed between the exothermic tubular body and the hollow core metal. Was injected to obtain the desired heat fixing roll. At this time, a primer layer was formed on the inner surface of the exothermic tubular body.

  As a primer, trade name “XP-81-405” manufactured by GE Toshiba Silicone was used. In the primer treatment, after applying a mixture of liquid A and liquid B in a ratio of 1: 1 in advance, the exothermic tubular body is dried at room temperature for 20 minutes, and further dried at 150 ° C. for 20 minutes. I let you.

  As the silicone rubber precursor, liquid silicone rubber (trade name “XE15-B7354” manufactured by GE Toshiba Silicone Co., Ltd.) was used. Specifically, the two liquids A and B were preliminarily in a ratio of 1: 1. In addition, after casting of the silicone rubber precursor, the silicone rubber precursor was subjected to primary vulcanization at a temperature of 150 ° C. for 10 minutes, and further at a temperature of 200 ° C. for 4 hours. The silicone rubber precursor was subjected to secondary vulcanization to obtain an exothermic fixing roll having an outer diameter of 24 mm, electrode layers at both ends of 15 mm, and an overall length of 240 mm. The thickness was about 2 mm, and the test piece produced under the same vulcanization conditions had a rubber hardness of 45 degrees.

<Evaluation of heat fixing roll>
The heat fixing roll produced in this example was evaluated.

(1) Measurement of volume resistivity The volume resistivity of a heat generating tubular body having a total length of 240 mm, each having an electrode layer length of 15 mm, was measured using a digital multimeter Model 7562. The volume resistivity (LD) in the length direction of the heat generating tubular body is 35 × 10 ⁻⁴ Ωcm, and the measured value of the volume resistivity (DD) in the direction orthogonal to the length direction is 65 × 10 ⁻⁴ Ωcm. , Ra value was 1.85.

(2) Measurement of heat generation temperature distribution A power generation terminal was attached to the electrode layer, and a heat generation test was performed by the method shown in FIG. The power supply terminal was fixed in contact with the electrode layers at both ends of the heat-generating fixing roll. As shown in FIG. 4, a variable voltage regulator 52 was connected to the power source 51, and power was supplied from the power source 51 to the electrode layer 5 while setting the voltage by the variable voltage regulator 52. Specifically, first, the variable voltage regulator is set so that the surface of the heat fixing roll (release layer surface) becomes 220 ° C. while observing the surface temperature of the heat fixing roll by first setting the thermo tracer to the standard mode. After the output voltage of 52 was adjusted and the surface reached 220 ° C., power supply was continued in this state, and the temperature distribution at that time was measured. The output voltage at this time was 48V. Thereafter, the power supply was stopped and the heat fixing roll was naturally cooled until it reached room temperature.

  Next, the thermotracer was switched to the time trace mode, and the temperature rise change of the heat fixing roll for 10 seconds from the start of energization was observed and recorded. When the surface temperature in the length direction 10 seconds after the start of energization is read from the recorded data, the maximum temperature is 210.8 degrees C, the minimum temperature is 208 degrees C, and the temperature distribution is within 3 degrees C. It was possible to confirm the uniform heat generation rise characteristic. In particular, there was almost no temperature difference between the power supply terminals of the heat generating fixing roll, and very uniform heat generation was observed.

(3) Evaluation of incorporation into image fixing device The heat-generating fixing roll according to this example was incorporated into the image fixing device 30 shown in FIG. 3, and a toner image fixing test was performed. When the fixing temperature was set to 200 ° C. with a thermistor and a paper passing test was performed, fixing was possible immediately after the power was turned on, and a clear fixed image was obtained. In addition, the electrode layer was able to supply power stably without wear or contact failure.

  A heat-generating fixing roll was produced in the same manner as in Example 1 except that the elastic layer of the heat-generating tubular layer support roll was changed to foamed rubber in Example 1. The foamed rubber was manufactured as follows. First, a silicone rubber compound “KE151KU” (Shin-Etsu Chemical Co., Ltd.) was charged with 2 parts by weight of an organohydropolyene polysiloxane and 1 part by weight of 1,1′-azo-bis with respect to 100 parts by weight of the silicone rubber compound. Isobutyronitrile (foaming agent) and chloroplatinic acid (catalyst) were added to prepare a silicone rubber formulation. Next, the primer “No. 101A / B” (Shin-Etsu Chemical Co., Ltd.) was applied to the aluminum hollow core used in Example 1. And the hollow core body was dried at 180 degreeC temperature for 15 minutes. Next, the hollow core and the silicone rubber compound were integrally extracted by an extruder, and the silicone rubber compound was vulcanized at 250 ° C. for 10 minutes to produce a foamed rubber roll original. Thereafter, the foamed rubber roll original form was further treated at a temperature of 200 ° C. for 2 hours and then left at room temperature. And the foamed rubber roll original shape was ground to 30.5 mm with a cylindrical grinder. As a result of measuring the hardness of the foamed rubber based on JIS (K) 6253, the IRHD hardness was 80.

  And after apply | coating an adhesive agent to the surface of the foaming rubber of a heat generation tubular layer support roll, the heat generation tubular layer support roll was press-fit in the heat generation tubular body, and this was heat-processed at 130 degreeC for 1 hour.

  When this heat-generating fixing roll was incorporated in an image fixing apparatus and a full-color image was heat-fixed, a good image was obtained. It was also confirmed that the nip width by the press contact between the heat generating fixing roll and the pressure roll was wide. That is, it was confirmed that this heat generating fixing roll can be suitably used as a fixing roll for full-color images.

(A) It is a longitudinal cross-sectional view of the heat fixing roll which concerns on one Embodiment of this invention. (B) It is II sectional drawing of the heat fixing roll which concerns on one Embodiment of this invention. (A) It is a schematic side view of the heat fixing roll according to an embodiment of the present invention. (B) It is II-II sectional drawing of the heat fixing roll which concerns on one Embodiment of this invention. 1A is a schematic diagram of an image fixing apparatus according to an embodiment of the present invention. (B) It is III-III sectional drawing of the image fixing apparatus which concerns on one Embodiment of this invention. It is a figure for demonstrating the exothermic temperature distribution measuring method of the exothermic fixing roll which concerns on the Example of this invention. It is a microscope picture of the nickel fine particle in which the strand connected in three dimensions. 2 is an electron micrograph showing an orientation state of carbon nanofibers in a resistance heating element layer produced based on the description of Example 1. FIG. It is explanatory drawing of the immersion casting method. 1 is a schematic view of a film fixing type image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st insulating layer 2 Resistance heating element layer 3 2nd insulating layer 4 Release layer 5 Electrode layer 6 Elastic layer 7 Roll core metal 33 Roll feed terminal 35 Core metal of pressure roll 36 Pressure roll 42 Power supply N nip part

Claims (12)

The core,
An elastic layer formed on the outer peripheral surface of the core;
A heat-generating fixing roll comprising a heat-generating tubular body formed on the outer peripheral side of the elastic layer and having at least a resistance heat-generating body layer, an insulating layer, a release layer, and a conductive electrode layer. The heat generating fixing roll according to claim 1, wherein the elastic layer has a hardness of 3 degrees or more and less than 60 degrees. The heat generating fixing roll according to claim 1, wherein the elastic layer is a foam. The heat-generating fixing roll according to any one of claims 1 to 3, wherein the resistance heating element layer is made of a polyimide resin in which carbon nanomaterials and filament-like metal particles are dispersed. The heat fixing roll according to claim 4, wherein the carbon nanomaterial is at least one conductive material selected from the group consisting of carbon nanofibers, carbon nanotubes, and carbon microcoils.   The heat-generating fixing roll according to claim 4 or 5, wherein the filamentary metal particles are nickel particles having a shape in which strands are three-dimensionally connected. The heat-generating fixing roll according to any one of claims 4 to 6, wherein the carbon nanomaterial and the filamentary metal particles are oriented in substantially one direction. The carbon nanomaterial and the filamentous metal particles are oriented in the length direction,
The heat generating fixing roll according to claim 7, wherein the volume resistivity in the length direction is smaller than the volume resistivity in a direction orthogonal to the length direction. The polyimide resin is a polyimide resin obtained by imidizing a polyimide precursor obtained by polymerizing at least one aromatic diamine and at least one aromatic tetracarboxylic dianhydride in an organic polar solvent. The heat generating fixing roll according to any one of 4 to 8. 2. The insulating layer comprises a polyimide resin obtained by imidizing a polyimide precursor obtained by polymerizing at least one aromatic diamine and at least one aromatic tetracarboxylic dianhydride in an organic polar solvent. The heat-generating fixing roll according to any one of items 1 to 9.   The aromatic diamine is paraphenylene diamine (PPD), and the aromatic tetracarboxylic dianhydride is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA). The heat-generating fixing roll according to 9 or 10. An exothermic fixing roll according to any one of claims 1 to 11,
An image fixing device comprising: a power supply means for supplying power to the heat generating fixing roll.