JP2005265998A - Fixing member, fixing device, fixing method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing member, capable of realizing the improvement of wear resistance and the prevention of offset, and further realizing the prevention of electrostatic offset, the uniformization of heat conduction, the improvement of image quality and the prevention of the peeling of a releasing layer, and further to provide a fixing method for improving the prevention of offset, a fixing device realizing the improvement of wear resistance by its constitution, and an image forming apparatus. <P>SOLUTION: In the fixing member having heat-resistant base material and the releasing layer formed on the heat-resistant base material, the releasing layer is obtained by aggregating compound powder, having particles containing fluororesin and an outer shell surrounding the outside of the particle containing the fluororesin and composed of heat-resistant resin, whose Martens hardness HM at a temperature range of 15°C to 250°C is higher than the value of the fluororesin and forming it into film. The fixing device is equipped with the fixing member. The fixing method uses the fixing device. The image forming apparatus is equipped with the fixing device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fixing member, a fixing device, a fixing method, and an image forming apparatus, and in particular, a fixing member, a fixing device, and a fixing method using an electrostatic transfer process such as an electrostatic copying machine and an electrostatic copying printer. And an image forming apparatus.

  Conventionally, as a fixing device for an image forming apparatus such as a general electrophotographic copying machine, various fixing methods have been proposed and implemented. Among them, at least one of a roller fixing type, in particular, a roller pair. A heating roller fixing device (heat roll fixing method), which is a heating roller heated by a heat source, is mainly used.

  Here, of the pair of rollers, a roller in contact with the surface on the image carrying side of the recording material is referred to as a fixing roller or a heating roller, and the other roller is referred to as a pressure roller.

  In the roller fixing type fixing device, since the fixing roller is in direct contact with the image carrying surface of the recording material, a part of the developer (hereinafter referred to as toner) constituting the image on the recording material is part of the above. A so-called “offset phenomenon” is easily generated in which the adhered toner adheres to the surface of the fixing roller and the adhered toner is transferred onto the recording material again as the roller rotates.

  Accordingly, as a means for preventing this offset phenomenon, conventionally, a highly releasable material such as polytetrafluoroethylene resin (hereinafter referred to as PTFE) such as polytetrafluoroethylene resin (hereinafter referred to as PTFE) or silicon rubber (non-adhesive) has been conventionally used. A means for providing a coating layer for preventing the offset of the adhesive material and improving the releasability (non-adhesiveness) of the surface layer of the fixing roller has been adopted.

  However, with the above-described offset prevention layer, a roller provided with a fluororesin coating layer such as PTFE exhibits excellent non-adhesiveness, but depending on the type of toner resin, there are some toners with poor releasability. May stick to contaminate the roller surface.

  In recent years, high durability of various parts such as fixing rollers has been strongly demanded due to the trend toward lower costs, improved serviceability, industrial waste regulations, etc. Is not so tough, and a fixing roller provided with a coating layer of fluororesin such as PTFE has the disadvantages of insufficient wear resistance and short life.

  In other words, the surface of the fixing roller is worn by being rubbed by a cleaning means such as a blade, a release agent applying means, a recording material separating claw, a temperature detecting element, a pressure roller, or the like. Further, it is also rubbed by the recording material passing between the fixing roller and the pressure roller. When a large amount of paper (recording material) is passed, paper dust generated from the paper adheres to the fixing roller. This paper dust is removed by a cleaning blade or the like in contact with the fixing roller. However, particularly at the edge portion of the paper, the generation of paper dust is remarkable, and the roller surface is worn by various inorganic fillers contained in the paper dust. To do. The fixing roller tends to lose its original releasability due to loss of smoothness due to surface wear.

  In addition, since the coating layer has a high resistance, the surface of the coating layer is greatly charged by frictional charging due to rubbing against the recording material / pressure roller and other roller contact members, and the toner on the recording material is electrostatically charged. It is attracted to the surface of the fixing roller by the action, and so-called “electrostatic offset phenomenon” is likely to occur.

  The fluororesin is largely negatively (−) charged by rubbing against the recording material or the like. When the toner has a positive (+) polarity, the toner is attracted to the electric field of the coating layer of the negatively charged fluororesin and easily adheres to the surface of the fixing roller due to an electrostatic offset phenomenon.

  As a means to improve the above-mentioned wear resistance, in general, wear resistance such as fluororesin is compared with glass powder, silica, silicon carbide powder, diamond powder, corundum powder, metal powder such as nickel and iron, etc. It can be improved by mixing an inorganic filler with a high hardness, but if the amount of mixing is small, the effect of improving the wear resistance is not sufficient. Not only will it deteriorate, but the surface properties of the fixing roller will also deteriorate, and the effect of preventing offset will be reduced.

  The inorganic filler not only has a poor dispersibility in the fluororesin, but even if it can be dispersed, the adhesion between the filler and the fluororesin is poor and a part of the filler of the fixing roller coating layer due to durability or the like. If a phenomenon such as separation occurs, and if it cannot be dispersed, the portion with less filler is scraped into stripes or mottles first due to durability, etc., toner is embedded in the scraped portion, and the non-adhesiveness of the fixing roller Often caused a decline.

  Further, when the filler is detached, the toner is embedded in the detached portion, and the removed filler acts as an abrasive on the contrary, which causes problems such as accelerated wear.

  Attempts were made to make the particle size of the filler finer, but the adhesion between the filler and the fluororesin was poor, and conversely, the entire surface of the fluororesin layer was worn.

  Furthermore, since the fixing member with the release layer worn out cannot be used, it is necessary to replace the fixing member with a new fixing member, leading to waste of resources and increasing the burden on the environment which has been regarded as a problem in recent years.

  The following solutions have been proposed for these problems, but each has drawbacks and has not yet been fully resolved.

  In Patent Document 1 and Patent Document 2 (Claim 3), it has also been proposed to form a film mixed with a resin having excellent durability and adhesion. Depending on the manufacturing conditions, the surface structure tends to be uneven, and there is a disadvantage that the life varies with the roller, and the surface tension is not controlled, so it is not necessarily sufficient to release, especially in recent years. In the oilless fixing (fixing method in which the release member is not applied to the fixing member in advance and the release is performed only with the release agent in the toner), there is a potential problem that offset is likely to occur.

  In the invention described in claim 1 and claim 2 of Patent Document 3, it is expected that the fluororesin layer floats on the surface by heating, as described in paragraph 0022. Is not thin and the structure is not controlled to maintain surface tension suitable for mold release. If the surface is damaged in any way, a polyimide layer with poor mold release will be exposed, which will adhere to the toner. Became the core of, and sometimes led to jam. This tendency was particularly remarkable in oilless fixing which has become mainstream in recent years.

  In claims 1 to 4 of Patent Document 4, as described in paragraphs 0023 and 0024, it is also proposed to form a film mixed with a resin having excellent durability and adhesion. Since the tension was not controlled, it was difficult to say that the releasability was sufficient. In particular, in oilless fixing (fixing method in which the release agent is not applied to the fixing member in advance and the release is performed only with the release agent in the toner), offset is likely to occur. I had it.

  In Claims 1 to 3 of Patent Document 5, as described in paragraph 0016, the binder resin is mixed with fluororesin particles or once melted fluororesin particles, and wear resistance is maintained while maintaining release properties. However, in this case, the components of the fluororesin particles are detached from the binder resin when subjected to strong rubbing or digging force by a separation claw for paper separation, etc. There was a disadvantage that an offset was generated from the holes generated in the case.

  In Patent Document 6, as described in paragraph 0005, it is also proposed to form a film in which a fluororesin is mixed with a resin excellent in durability and adhesion, but as in paragraphs 0025 and 0029, When a liquid is mixed with a resin having a high specific gravity, such as a fluororesin, depending on the adjustment conditions and manufacturing conditions of the liquid, the fluororesin of the release layer There were drawbacks in that the ratio was easily uneven and the life was varied and cheaper by the roller. In particular, the oilless fixing (fixing method in which the release agent is not applied to the fixing member in advance and the release is performed only with the release agent in the toner) has a potential disadvantage that offset is likely to occur. I had it.

  On the other hand, the deflection temperature under load of the heat-resistant resin (ASTM D648, 1.82 MPa) is not necessarily a value having a correlation with the amount of deformation at the time of pressing, so the order of the deflection temperature under load of the heat-resistant resin (ASTM D648, 1.82 MPa) And Martens hardness HM (ISO 14577-1: 2002 (E) A.2) (hereinafter sometimes simply referred to as “Martens hardness HM”) at the time of fixing completely correspond to each other. In some cases, the order may be reversed, and it has been pointed out that sufficient wear resistance cannot be obtained.

Further, even when a heat-resistant resin having a Martens hardness HM larger than that of a fluororesin is used, the heat-resistant resin is not necessarily uniformly dispersed, and the heat-resistant resin is excessively present, thereby inhibiting releasability. It was pointed out that this could occur.
Japanese Patent Laid-Open No. 2003-12885 Japanese Patent Laid-Open No. 04-243287 JP 2000-298411 A JP 2001-312170 A JP 2001-331049 A Japanese Patent No. 3261166

  The present invention has been made in order to eliminate the above-described drawbacks of the prior art, and an object of the present invention is a fixing member that can improve wear resistance and prevent offset. Fixing member that can prevent heat release, uniform heat conduction, improve image quality, and prevent peeling of the release layer, fixing method that improves prevention of offset, and further, wear resistance by fixing device configuration An object of the present invention is to provide a fixing device that can be improved and an image forming apparatus having these characteristics.

  As a result of various studies, the present inventor has formed a heat-resistant substrate and a heat-resistant substrate, encloses the fluororesin particles and the outside of the fluororesin particles, and the temperature at the time of fixing from room temperature. Fixing member having a release layer formed by assembling a composite powder comprising an outer shell made of a heat-resistant resin having a Martens hardness HM of an arbitrary temperature in the range of up to a value higher than that of a fluororesin As a result, the present inventors have found that the above-mentioned problems can be achieved and have come to the present invention.

  That is, the fixing member of the present invention is a fixing member having a heat-resistant substrate and a release layer formed on the heat-resistant substrate, and the release layer includes particles containing a fluororesin. And a composite powder comprising an outer shell made of a heat-resistant resin that surrounds the outside of the particles containing the fluororesin and has a Martens hardness HM at a temperature of 15 ° C. to 250 ° C. larger than the value of the fluororesin. It is characterized by being formed into a film after.

  The Martens hardness HM in the present invention is ISO 1457-1: 2002 (E). This means what is specified in 2. That is, using a diamond indenter (Vickers indenter) with a facing angle (136 °) at the tip of a quadrangular pyramid, the indentation depth under a test load is measured as shown in FIG.

  With conventional methods such as Vickers hardness and Mohs hardness, it is possible to measure plastic deformation with the measurement of indentations and scratches after the test, but since the elastic deformation is unknown, the true deformation amount during pressing There was a problem that could not be measured. For elastic deformation, there is another method of measuring rubber hardness, but with rubber hardness, even if the relative order between materials is known, there is no correlation with the amount of deformation during pressing, and the true amount of deformation during pressing is still the same. It was unknown.

  In any of the above-described methods, when the thickness of the sample is 50 μm or less, the influence of the hardness of the substrate cannot be removed, and correct measurement is difficult.

  On the other hand, the Martens hardness HM allows the first evaluation of the hardness in a form in which both plastic deformation and elastic deformation during pressing are integrated.

  In the methods such as the Vickers hardness and the Mohs hardness described above, in a material having deformation recovery due to the elastic memory effect, such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), at high temperatures, This makes it impossible to make an accurate evaluation, so that there is another problem that an accurate value cannot be measured.

  An example of the Martens hardness of the fluororesin and heat resistant resin at 180 ° C., which is an example of the temperature of the release layer at the time of fixing, is shown in Table 1, and the Martens hardness of the fluororesin and heat resistant resin at 25 ° C., which is an example of room temperature. An example is shown in Table 2.

In actual measurement, a microhardness measuring device, Fischer scope H100V (manufactured by H. Fischer) was used, and a test load F (N) was gradually applied according to the program, and the indenter indentation depth under the test load The thickness h (mm) was electrically detected and read, and the Martens hardness HM (N / mm ² ) was calculated based on HM = F / (26.43 × h ² ). About the measurement sample, what used the fluororesin and the heat resistant resin as a 50-micrometer-thick each coating film was used. The measurement sample and the ambient temperature were measured after stabilization at the measurement temperature.

  The release layer may be configured such that a part or all of the particles constituting the outer shell made of the heat resistant resin are melted.

  The thickness of the outer shell made of the heat resistant resin may be smaller than the particle size of the toner.

  The fixing member may have a configuration in which a layer made of only a fluororesin is laminated on the surface of the release layer.

  The particle | grains containing the said fluororesin can take the structure that an electroconductive filler is contained.

  The particle | grains containing the said fluororesin can take the structure that a heat conductive filler is contained.

  The fixing member may have a configuration in which an elastic layer is provided between the heat resistant substrate and the release layer.

  The fixing member may be configured such that a part of the surface of the heat resistant resin is bonded to the heat resistant substrate or the elastic layer.

  The fixing member may have a configuration in which an adhesive layer is provided between the release layer and the heat resistant substrate or the elastic layer.

  In the fixing member, the resin existing on the surface of the heat-resistant substrate and the outer shell made of the heat-resistant resin of the release layer are the same type of resin, and the release layer is the heat-resistant substrate. It is possible to adopt a configuration in which it is formed directly on the top.

  The fixing device according to the present invention includes the fixing member and a member that contacts the fixing member for separating the recording material on which the toner is fixed from the fixing member.

  The fixing device may further comprise a means for supplying a release agent to the surface of the release layer.

  The fixing device may further have a configuration in which means for cleaning the surface of the release layer is provided.

  The fixing device can take a configuration in which the Martens hardness HM at a temperature of 15 ° C. to 250 ° C. of the member abutting on the fixing member is smaller than the value of the heat resistant resin.

  The fixing method of the present invention is characterized in that the electrophotographic image is fixed by using the fixing device and supplying a release agent to the surface of the release layer.

  Another fixing method of the present invention is characterized in that the surface of the release layer is cleaned and the electrophotographic image is fixed using the fixing device.

  The image forming apparatus of the present invention includes the fixing device.

  In the fixing member of the present invention, since the release layer is formed on the surface of the fixing member by assembling a composite material including particles containing fluororesin and an outer shell made of a heat-resistant resin. Excellent heat resistance, and the Martens hardness HM of the heat-resistant resin that is the outer shell is larger than the value of fluororesin at the fixing temperature. Therefore, cleaning means such as blades, release agent application means, recording material separation claw, temperature detection Even when pressed by an element, a pressure roller, or the like, they are less likely to be deformed than a release layer made of only a fluororesin, so that they are less likely to bite and therefore less likely to wear.

  In the fixing member of the present invention, when a part or all of the particles constituting the outer shell made of the heat resistant resin are melted, the release layer is compared with the case where the particulate heat resistant resin is dispersed. Even if the heat-resistant resin on the surface does not easily detach even when subjected to the force of digging by a separation claw or the like, it is difficult to open a hole, and image defects and wear are unlikely to occur. Also, since the wax that comes out of the toner and adheres to the release layer side is not repelled on the release layer, the toner resin or the like directly touches the release layer to be offset or a hot melt adhesive. Thus, the recording material does not wrap around the fixing roller.

  In the fixing member of the present invention, when the thickness of the outer shell made of the heat resistant resin is smaller than the particle diameter of the toner, the area where the toner directly contacts the heat resistant resin is reduced, which is advantageous for preventing offset. become.

  In the fixing member of the present invention, when a layer made of only a fluororesin is laminated on the surface of the release layer, a structure advantageous for durability and offset prevention regardless of the composite ratio of the heat resistant resin and the fluororesin Can be formed.

  In the fixing member of the present invention, when the conductive filler is contained in the particles containing fluorine, electrostatic offset can be effectively prevented.

  In the fixing member of the present invention, when the thermally conductive filler is contained in the particles containing fluorine, the thermal conductivity can be improved.

  In the fixing member of the present invention, when an elastic layer is provided between the heat resistant substrate and the release layer, compared to a case where no elastic layer is provided between the heat resistant substrate and the release layer. The heat-resistant resin is compounded, and it is possible to improve the adhesion to the elastic layer, which is advantageous for heating the toner uniformly or increasing the nip width to increase the linear velocity of the sheet passing.

  In the fixing member of the present invention, when a part of the surface of the heat resistant resin adheres to the heat resistant substrate or the elastic layer, the heat resistant substrate or the elastic layer and the release layer are used without using the adhesive layer. Therefore, it is not necessary to apply and dry the adhesive layer, and the number of steps can be reduced.

  In the fixing member of the present invention, when an adhesive layer is provided between the release layer and the heat-resistant substrate or the elastic layer, a cleaning means such as a blade, a release agent coating means, a recording material separation claw In addition, it is possible to prevent the release layer from being peeled when it is rubbed by a temperature detection element, a pressure roller, or the like.

  In the fixing member of the present invention, the resin present on the surface of the heat resistant substrate and the outer shell made of the heat resistant resin of the release layer are the same type of resin, and the release layer is on the heat resistant substrate. In the case where the adhesive layer is formed directly, the adhesion between the heat-resistant substrate and the release layer can be improved without using an adhesive layer, and it is not necessary to apply and dry the adhesive layer. Can be reduced.

  The fixing device of the present invention is provided with the fixing member, so that the above-described effect of the fixing member of the present invention occurs. In addition, when a large amount of paper (recording material) is passed, it is generated from the paper. Even if the paper powder to be adhered to the fixing member and the surface of the release layer is rubbed by various inorganic fillers contained in the paper powder, it is difficult to wear.

  In the fixing device and fixing method of the present invention, when a release agent is supplied to the surface of the release layer, the oil component is retained in the heat-resistant resin, and the coating layer for preventing offset is stable over a long period. Adhesiveness is shown and toner does not adhere.

  In the fixing device of the present invention, when the Martens hardness HM at a temperature of 15 ° C. to 250 ° C. of the member in contact with the fixing member is smaller than the value of the heat resistant resin, the member in contact with the release layer Even if pressed, the member is less likely to be deformed, so that the member to be abutted is less likely to bite into the release layer, and it is possible to further reduce wear.

  According to the image forming apparatus of the present invention, since the usable period of the fixing member is greatly increased, resource saving is achieved, and it is possible to reduce the load on the environment which has been regarded as a problem in recent years.

  The fixing member of the present invention is a fixing member having a heat-resistant substrate and a release layer formed on the heat-resistant substrate, and the release layer includes particles containing a fluororesin and a fluororesin. A composite powder comprising an outer shell made of a heat-resistant resin having a Martens hardness HM at a temperature of 15 ° C. to 250 ° C. larger than that of a fluororesin is collected and then formed into a film. It is characterized by being.

  The heat-resistant base material is not particularly limited as long as it is a metal cylindrical cored bar, and examples thereof include an aluminum fixing roller cored bar. For example, the surface of the fixing roller core bar made of aluminum may be blasted and roughened.

  The fluororesin used for the particles containing the fluororesin is not particularly limited as long as it contains a fluorine atom in the molecule. Specifically, for example, polytetrafluoroethylene (PTFE) and a modified product thereof, Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-vinylidene fluoride copolymer Polymer (TFE / VdF), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPA), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), copolymer B trifluoroethylene - vinylidene fluoride copolymer (CTFE / VdF), polyvinylidene fluoride (PVdF), and the like polyvinyl fluoride (PVF).

  The heat resistant resin is not particularly limited as long as the Martens hardness HM at a temperature of 15 ° C. to 250 ° C. is larger than that of the fluororesin, but at a temperature between room temperature and the temperature of the release layer at the time of fixing. It is also preferable to mix a heat resistant resin having a Martens hardness HM larger than that of the fluororesin. Depending on the fixing device, when the surface of the release layer is heated from room temperature to a temperature at which fixing can be performed, the fixing member is rotated to quickly stabilize the surface temperature of the pressure member in contact with the fixing member at a uniform temperature. However, if a heat resistant resin having a Martens hardness HM larger than that of the fluororesin is mixed even at a temperature between room temperature and the temperature of the release layer at the time of fixing, cleaning means such as a blade, Even if pressed by a mold application means, a recording material separation claw, a temperature detection element, a pressure roller, etc., they are less likely to be deformed compared to a release layer made of only a fluororesin, so that they are less likely to bite and thus more difficult to wear. It is.

  Here, the temperature of the release layer at the time of fixing is usually set in the range of 80 ° C to 250 ° C. If the temperature is lower than 80 ° C., the melting temperature of the toner to be used must be lowered. Therefore, the toner tends to adhere and harden in the container due to an increase in the temperature in the copying machine or the like. This is because, when the temperature is higher, the thermal deterioration of the fluororesin becomes remarkable and the life of the release layer is shortened. In order to perform stable fixing, the temperature of the release layer at the time of fixing is more preferably set in the range of 100 ° C to 200 ° C. For example, when the temperature of the fixing member is 150 ° C., specifically, polyamideimide (PAI), polyethersulfone (PES), polyetherimide (PEI), polybenzimidazole (PBI), polyimide (PI) ) Etc. can be used. These may be used in combination.

  An example of a method for producing a composite powder including particles containing a fluororesin and an outer shell made of a heat-resistant resin that surrounds the outside of the particle containing the fluororesin is shown below. The heat-resistant resin particles having an average particle size of 0.1 to 50 μm are obtained by, for example, using a solution obtained by dissolving a heat-resistant resin in a good solvent (a solvent having a high solubility in the heat-resistant resin) in a poor solvent (heat-resistant resin). In a solvent having a low solubility with respect to the solvent) while being mixed and dispersed using a high-speed shearing stirrer and pulverizing with a wet pulverizer.

  Examples of the good solvent include (1) dimethylformamide for polyethersulfone (PES), (2) dichloromethane, N-methyl-2-pyrrolidone, trichloroethane for polyetherimide (PEI), (3 ) For chloroform, dichloromethane, tetrahydrofuran, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, polyamideimide (PAI), (4) dimethylformamide, diethylacetamide, N-methyl-2-pyrrolidone, hexamethylphospho Examples of amide and polybenzimidazole (PBI) include dimethylacetamide.

  Examples of the poor solvent include ether-based organic solvents such as dioxane, tetrahydrofuran and diglyme, hydrocarbon-based organic solvents such as toluene and xylene, ketone-based organic solvents such as cyclohexanone, cyclopentanone, methyl ethyl ketone, and methyl isobutyl ketone. The material is not particularly limited as long as it has a low solubility in the heat-resistant resin. However, in order to prevent aggregation due to liquid crosslinking between the particles of the heat-resistant resin and for quick drying, the water content is small and volatile. preferable.

  The high-speed shearing type stirring device may be a product generally known to those skilled in the art under a trade name such as “homogenizer” or “homomixer”. Further, there are various types such as a capacity, a rotational speed, and a model, but those having a stirring Reynolds number of 10,000 or more are preferable, and an appropriate one may be used according to the production mode and the like. The wet pulverizer may be a generally known fine particle pulverizer such as a ball mill using a pulverizing medium, a bead mill and the like, or a two-liquid collision type pulverizer.

  For example, when a resin solution in which polyetherimide (PEI) is dissolved as a resin solid content in dichloromethane as a good solvent is added to toluene as a poor solvent while stirring at a rotation speed of 1500 rpm using a homogenizer, resin precipitates are formed. can get. Of the obtained resin product, the dispersion is subjected to adsorption filtration and washed with toluene, and then the resin product is redispersed in toluene to obtain a resin dispersion having a solid content of 10% by weight. When this resin dispersion is crushed at 2000 rpm by using a wet pulverizer bead mill, a dispersion of resin particles is obtained. The volume-based 50% average particle diameter of the obtained resin particles is, for example, 0.5 μm. Thereafter, when drying under reduced pressure is performed for 3 hours, particles of polyetherimide (PEI) are obtained. In addition, particles can be obtained in the same manner for polyethersulfone (PES) and polybenzimidazole (PBI).

  Particles having an average particle size of 1 μm or less of polyimide (PI) having no good solvent can be produced by a method different from the above method, for example, by the following method. That is, (I) and (II) dissolve aromatic tetracarboxylic dianhydride (hereinafter sometimes referred to as “I”) and aromatic diamine (hereinafter also referred to as “II”). However, in the organic solvent in which the produced polyamic acid does not dissolve (hereinafter sometimes referred to as “III”), the total amount of (I) and (II) is made 10% by weight or less with respect to (III). The obtained polyamic acid particles are heated to imidize in an organic solvent (hereinafter sometimes referred to as “IV”) that does not dissolve the polyamic acid particles and the resulting polyimide particles.

  Specifically, 200 mg of 4,4'-diaminodiphenyl ether and 41.8 g of cyclohexanone and 41.8 g of cyclohexanone were put into a 100 ml flask equipped with a thermometer, a stirrer and a nitrogen introducing tube while passing nitrogen gas, and 200 rpm The temperature was raised to 50 ° C. while stirring at 145 ° C., and at this temperature, 218 mg (0.001 mol) of pyromellitic dianhydride was added (the total amount of pyromellitic dianhydride and 4,4′-diaminodiphenyl ether was added to cyclohexanone. 1% by weight) for 30 minutes to form particles. The obtained particles are centrifugally purified (3 times with cyclohexanone, 3 times with acetone, and each time at 13500 rpm for 10 minutes), and then dried under reduced pressure for 3 hours to obtain yellow polyamide particles. The weight average molecular weight of the obtained polyamide particles is, for example, 11300, the weight average particle diameter (Dw) determined from the image analysis of the transmission electron micrograph is 0.36 μm, and the number average particle diameter (Dn) is 0.35 μm and the dispersity (Dw / Dn) is 1.03. Thereafter, 50 g of 1-dodecanol and 1 g of triethylamine were placed in a 100 ml flask equipped with a thermometer, a stirrer and a nitrogen introducing tube, and then 300 mg of the above-mentioned polyamide particles were dispersed and heated at 200 ° C. for 1 hour with stirring. Then, imidization reaction is performed. Next, the polyamide particles are centrifugally purified (3 times with acetone, each at 13500 rpm for 10 minutes), and then dried under reduced pressure for 3 hours to obtain yellow polyimide particles. The volume-based 50% average particle size of the obtained polyimide particles is, for example, 0.3 μm.

  As a method for producing a composite powder using heat-resistant resin particles and fluororesin powder, for example, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) powder (manufactured by Mitsui DuPont) can be used as the fluororesin. , MP102, average particle diameter φ20 μm), and using the above-mentioned polyetherimide (PEI) particles (average particle diameter φ0.5 μm) as the heat-resistant resin, mixing at a predetermined weight ratio can be mentioned.

  As a device for producing a composite powder by mixing, a commercially available product such as a mortar, a ball mill, a Henschel mixer and an improved type can be used simply, and a high-speed rotary impact pulverizer such as a hammer mill, a pin mill, etc. A part or all of a system such as a jet mill, a hybridization system manufactured by Nara Machinery Co., Ltd., or a kryptron manufactured by Kawasaki Heavy Industries, Ltd. can be used.

  For example, using a hybridization system made by Nara Machinery Co., Ltd. from 900 g of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) (average particle diameter φ20 μm) and polyetherimide (PEI) (average particle diameter φ0.5 μm) 100 g Then, a polyetherimide (PEI) -coated tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) is obtained.

  A film-like outer shell can be formed by rapidly heating the surfaces of the particles constituting the outer shell made of the heat-resistant resin and melting only the particles of the heat-resistant resin. As a method for applying heat to the particles, a heat fluidized bed in which particles are dispersed and fluidized in a hot air stream, a surfing system of Nippon Pneumatic Co., Ltd., or the like is used. When treated with a surfing system SFS-3 (manufactured by Nippon Pneumatic Co., Ltd.) at a hot air temperature of 380 ° C. and the polyetherimide particles are fused and connected, the tetrafluoroethylene-perfluoro shown in FIG. It can be set as the state of the outer shell which wraps an alkyl vinyl ether copolymer. In addition, composite powders having the structure shown in FIGS. 2B and 2C in which polyimide and another heat resistant resin are combined can also be manufactured.

  If necessary, it is also possible to produce a composite powder in which the composite powder is further coated with fluororesin particles having a diameter of 1 μm or less. For example, the composite powder is 50 of tetrafluoroethylene-hexafluoropropylene copolymer particles (Teflon (R) 120-J, average particle size 0.2 μm, manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: hereinafter abbreviated as FEP). After mixing with 16.6 ml of a weight% aqueous suspension (containing 8.3 g as FEP resin), the mixture was treated with ultrasonic waves for 5 minutes to obtain a uniform suspension of the composite powder and the FEP particles. When the suspension is dried, composite particles having FEP particles attached to the surface of the composite powder can be obtained.

  Thereafter, using a surfing system SFS-3 (manufactured by Nippon Pneumatic Co., Ltd.), when the FEP particles are melt-coupled by treatment at a hot air temperature of 300 ° C., the shell further enveloping the composite powder as shown in FIG. State.

  The process for forming the release layer with the composite powder will be described. The heat-resistant substrate is roughened by, for example, blasting the surface of an aluminum fixing roller core metal having a diameter of 40 mm and a fixing portion thickness of 1.5 mm. After that, when only the composite powder is used, the composite powder described above is electrostatically coated on the core metal of an aluminum fixing roller as a heat-resistant substrate, heated at 380 ° C. for 30 minutes, and outside the heating furnace. Quench with strong air. Thereby, a desired release layer can be obtained. When the fluororesin powder and the composite powder are used in combination, the powders are mixed at a predetermined weight ratio, and the mixed powder is applied to the core metal of an aluminum fixing roller as a heat-resistant substrate. It is electrostatically coated, heated at 380 ° C. for 30 minutes, and rapidly cooled by strong air outside the heating furnace. Also by this, a desired release layer can be obtained.

  Regarding the effect of the structure of the release layer, the conventional release layer for improving wear resistance is, for example, a release layer obtained by simply mixing a heat-resistant resin and a fluororesin as shown in FIGS. For this reason, the heat-resistant resin and the fluororesin each aggregated, and the arrangement was not uniform. For this reason, there is a problem in that there are places where the releasability is extremely inferior or places where the wear resistance is extremely inferior in one fixing member. However, in the present invention, as shown in FIG. 6, a release layer is formed using composite powder, and the heat resistant resin and the fluororesin always move together during electrostatic coating. Since the arrangement of the fluororesin becomes uniform, it is possible to improve the releasability and wear resistance regardless of the location of the fixing member.

  Even if the particulate resin as shown in FIGS. 4 and 5 is dispersed, the particulate resin exposed to the surface of the release layer is separated by a separation claw, etc. There is another problem that when a digging force is applied, it is detached and a hole is formed, and an offset is generated therefrom.

  In the fixing member of the present invention, it is preferable that the release layer is obtained by melting part or all of the particles constituting the outer shell made of a heat resistant resin.

  As shown in FIGS. 7 to 13, for example, as shown in FIGS. 7 to 13, the release layer is formed by melting part or all of the particles constituting the outer shell made of the heat resistant resin. Because they are connected inside, the heat resistant resin on the surface of the release layer is not easily detached even when subjected to the force of digging by the separation claws, etc., compared to the dispersion of normal particulate heat resistant resin. Is difficult to open, and thus image defects and wear are less likely to occur.

  In order to form this release layer, for example, a composite powder as shown in FIG. 2 can be used.

  Depending on the type and mixing ratio of the powder, the surface roughness of the release layer may be large. However, if it is necessary to make the surface roughness uniform to a predetermined size, for example, polishing with a tape polishing device. Is possible. For example, when tape polishing is performed with corundum # 800 and # 1500, the surface roughness Rz can be reduced to 2 μm or less.

  The fixing member has a charge-and-separation property by previously applying a release agent such as silicone oil. However, an oil-less fixing method (a release agent such as silicone oil or the like, which has been widely used in recent years) In the method of fixing toner without coating), as the mixing ratio of the heat-resistant resin in the composite powder is increased, the toner adheres to the outer shell of the heat-resistant resin exposed on the surface of the release layer, and the toner is released. Since the moldability may be insufficient, the toner peel strength was measured.

  Using a copying machine MF4570 manufactured by Ricoh Co., Ltd., an OHP sheet was used as an image carrier, a black solid unfixed sheet was cut into a width of 10 mm, and was wound around the roller prepared by the method described above. For 10 minutes. Thereafter, the mixture was cooled to room temperature, a 10 mm-wide black solid OHP sheet was peeled off, and the toner peel strength was measured.

  Table 3 shows the measurement results of the toner peel strength for the fixing roller made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and polyetherimide (PEI).

  From this result, it is generally found that the one containing 5 to 30% by weight of polyetherimide (PEI) having strong adhesion to the toner is one having 100% tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). The toner peel strength was lower than that.

  The reason is considered as follows. In the case of 100% tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), the wax that comes out of the toner and adheres to the release layer side is repelled on the release layer and the toner resin is released directly. There are many places that touch the mold layer. On the other hand, when 5 to 30% by weight of polyetherimide (PEI) is added, the wax positively develops on the polyetherimide (PEI) portion and promotes toner peeling. As a result, the recording material does not wrap around the fixing roller by functioning like an offset or hot melt adhesive, and toner releasability and wear resistance can be improved at the same time. However, if polyetherimide (PEI) is added in an amount of more than 30% by weight, it becomes impossible to cover all of the polyetherimide (PEI) with wax. This is because the recording material is wound around the fixing roller by touching (PEI) and functioning like a hot melt adhesive.

  Table 4 shows the measurement results of the toner peel strength for a fixing roller made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and polyimide (PI) under the same conditions as described above.

  From the results shown in Table 3 and Table 4, if the heat-resistant resin is mixed in such a ratio that the wax actively develops in the heat-resistant resin shell and the toner does not adhere to the outer shell of the heat-resistant resin itself, I found it good. In the present invention, the form of the fixing member is not limited to the fixing roller, and can be applied to any form such as a fixing belt.

  In the fixing member of the present invention, the thickness of the outer shell made of a heat resistant resin is preferably smaller than the particle size of the toner. When the release layer is formed by making the thickness of the outer shell made of heat-resistant resin smaller than the toner particle size, and the distance between the fluorine resins is smaller than the toner particle size, it is more non-adhesive than fluorine resin Even if the heat resistant resin inferior to the surface is exposed, as shown in FIG. 14, since the area where the toner directly contacts the heat resistant resin is reduced, the structure is advantageous for preventing the offset.

  In the fixing member of the present invention, it is preferable that a layer made of only a fluororesin is laminated on the surface of the release layer. For example, an advantageous structure for preventing offset as shown in FIG. 15 can be formed by further laminating a layer made of only a fluororesin on the release layer once formed.

  In the fixing member of the present invention, the particles containing the fluororesin preferably contain a conductive filler from the viewpoint of preventing electrostatic offset.

As the conductive filler, those having a resistance of 10 ¹⁰ Ω · cm or less are more preferable. Specifically, conductive polymers such as polyacetylene, polypyrrole and polythiophene, carbon such as ketine black and acetylene black, graphite, silver Metals such as nickel and copper, alloys thereof, composite metals plated on mica, carbon, glass, etc., metal oxides such as tin oxide and indium oxide, anions, cations, nonions, and amphoteric surfactants.

  The amount of the conductive filler is preferably 1 to 50% by weight with respect to the fluororesin, and is preferably 5 to 75% by weight in total with the heat resistant resin in order to maintain releasability.

  In the fixing member of the present invention, in order to improve the thermal conductivity, it is preferable that the particles containing the fluororesin contain a thermally conductive filler.

  Specific examples of the thermally conductive filler include diamond, silver, copper, aluminum, marble, glass, boron nitride, alumina, silicon carbide, potassium titanate, aluminum nitride, boron nitride, mica, silica, and titanium oxide. , Magnesium oxide, beryllium oxide, talc, calcium carbonate and the like, and mixtures of two or more thereof.

  The amount of the thermally conductive filler added is preferably 1 to 50% by weight with respect to the fluororesin in order to maintain releasability, and is preferably 5 to 75% by weight in total with the heat resistant resin.

  In the fixing member of the present invention, an elastic layer is preferably provided between the heat resistant substrate and the release layer. In order to heat the toner uniformly, increase the nip width, and increase the linear velocity of paper passing, the release layer formed on the elastic layer follows the uneven shape on the surface of the recording material. In the fixing member of the present invention, since the heat-resistant resin is mixed in the release layer, it is possible to improve the adhesion to the elastic layer compared to the case of using only the fluororesin. It can effectively prevent peeling of the release layer from the elastic layer when it is rubbed by a cleaning means such as a blade, a release agent application means, a recording material separation claw, a temperature detection element, a pressure roller, etc. Because it can.

  In the fixing member of the present invention, it is preferable that a part of the surface of the heat resistant resin is bonded to the heat resistant substrate or the elastic layer.

  As the heat-resistant resin here, one having heat resistance and adhesion on a metal cylindrical cored bar is selected, such as polyetherimide (PEI), polyamideimide (PAI), polyethersulfone (PES), and the like. Can be mentioned.

  As the fluororesin used here, one having a good melt film forming property by firing and a relatively low melting point (preferably 250 to 310 ° C.) is preferably selected. Specific examples include powders of low molecular weight polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). It is done. The low molecular weight polytetrafluoroethylene (PTFE) powders are Lubron L-5, L-2 (Daikin Industries), MP1100, 1200, 1300, TLP-10F-1 (Mitsui DuPont Fluorochemicals). Are known. As tetrafluoroethylene-hexafluoropropylene copolymer (FEP) powder, 532-8000 (manufactured by DuPont) is known, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) powder is MP-10, MP102 (made by Mitsui DuPont Fluorochemical Co., Ltd.) is known.

  By adhering a part of the surface of the heat-resistant resin to the heat-resistant substrate or the elastic layer, the adhesion between the heat-resistant substrate and the release layer can be improved without using an adhesive layer, It is possible to prevent the release layer from being peeled when it is rubbed by a cleaning means such as a blade, a release agent application means, a recording material separation claw, a temperature detection element, a pressure roller, or the like. For this reason, it is not necessary to apply and dry the adhesive layer, and the number of steps can be reduced.

  In the fixing member of the present invention, an adhesive layer is preferably provided between the release layer and the heat resistant substrate or elastic layer. By providing an adhesive layer between the release layer and the heat-resistant substrate or elastic layer, cleaning means such as a blade, release agent application means, recording material separation claw, temperature detection element, pressure roller, etc. This is because it is possible to prevent the release layer from being peeled when subjected to rubbing.

  As the adhesive layer, various commercially available heat-resistant primers that enhance the adhesion between the heat-resistant substrate and the release layer can be used. For example, for an aluminum roller, a polyimide-based primer, a polyamide-imide-based primer, a polyether Sulfone primers and mixed primers are preferably used. For example, for a heat-resistant endless belt layer of polyimide resin, a polyimide-based primer, a fluorine-based primer, or a mixed primer thereof is preferably used. Specifically, KUKUWARE (A primer) 459 manufactured by Deyupon Co., Ltd. -882, MP902BN manufactured by Mitsui Fluorochemical, MP910K manufactured by Mitsui Fluorochemical, etc. are used.

  In the fixing member of the present invention, the resin existing on the surface of the heat resistant substrate and the outer shell made of the heat resistant resin of the release layer are the same type of resin, and the release layer is made of the heat resistant substrate. It is preferably formed directly on the top.

  For example, for a heat-resistant endless belt layer such as polyetherimide or polyamideimide, polyetherimide or polyamideimide is also used as the heat-resistant resin constituting the release layer, and is separated directly on the heat-resistant endless belt layer. By forming the mold layer, the adhesiveness between the heat-resistant substrate and the release layer can be improved without using an adhesive layer, such as a cleaning means such as a blade, a release agent coating means, a recording material separation nail, Since it is possible to prevent the release layer from being peeled off when it is rubbed by a temperature detection element, a pressure roller, etc., there is no need to apply and dry the adhesive layer, which makes it possible to reduce the number of processes, Compared with the case where a release layer is formed on a cylindrical metal core, the adhesion can be further improved.

  The fixing device of the present invention includes the fixing member and a member that contacts the fixing member for separating the recording material on which the toner is fixed from the fixing member.

  A schematic cross-sectional view of one embodiment of the fixing device of the present invention is shown in FIG. The upper fixing roller (heating roller) 1 and the lower pressure roller 2 are pressed against each other with a predetermined pressing force in parallel up and down. The heat source 3 is a halogen heater built in the fixing roller 1, and the temperature detection element 4 is a thermistor in contact with the surface of the fixing roller 1. The surface temperature of the fixing roller 1 is detected by the temperature detection element 4, and the detection information is Accordingly, energization of the heat source 3 is controlled by a control circuit (not shown), and the surface temperature of the fixing roller 1 is managed at a predetermined temperature. The recording material separation claw 6 is urged against and brought into contact with the fixing roller 1 by a spring 7, and functions to separate the recording material to be attached to and wound on the surface of the fixing roller 1 from the fixing roller 1.

  In the pressure roller 2, the surface layer of the core metal 2b is covered with a silicon rubber layer 2a. The fixing roller 1 and the pressure roller 2 are rotationally driven at a predetermined speed by a driving unit (not shown). The recording material P is introduced into a clamping portion (fixing nip portion, nip width 5 to 6 mm) N between the fixing roller 1 and the pressure roller 2 after an unfixed toner image T is formed and supported by an image forming unit (not shown). Then, the toner image is fixed by heat and pressure by being nipped and conveyed by the nipping portion.

  In the fixing device of the present invention, since the release layer having an outer shell made of a heat resistant resin surrounding the fluororesin is formed on the surface of the fixing member, the heat resistance of the release layer is excellent. Since the Martens hardness HM of the heat resistant resin at a temperature of 15 ° C. to 250 ° C. is larger than that of the fluororesin, it is deformed as compared with the case of using only the fluororesin even when pressed by a recording material separation claw, a temperature detecting element, a pressure roller, etc. Since they are difficult to wear, they are less likely to bite and thus less wear. Even when a large amount of paper (recording material) is passed through, the paper powder generated from the paper adheres to the fixing member and the release layer surface is rubbed with various inorganic fillers contained in the paper powder for the same reason. It is hard to wear out. Since the wax that comes out of the toner and adheres to the release layer side is not repelled on the release layer, the resin of the toner directly touches the release layer and offsets it, like a hot melt adhesive. Therefore, the recording material is not wound around the fixing roller.

  The fixing device of the present invention preferably further includes means for supplying a release agent to the surface of the release layer, and further includes means for cleaning the surface of the release layer. Is preferred.

  A schematic cross-sectional view of another embodiment of the fixing device of the present invention is shown in FIG. Components that are the same as those in FIG. 16 are denoted by the same reference numerals, and description thereof is omitted. The roller body 5 serves as both an oil supply member and a cleaning member for the fixing roller 1. The roller body 5 is composed of a metal core 5a and an oil-impregnated heat-resistant felt 5b, and is controlled to contact and separate from the fixing roller 1 by an eccentric cam (not shown). Since the Martens hardness HM of the heat-resistant resin is larger than that of the fluororesin at the temperature at the time of fixing, it is difficult to be deformed even when pressed by the cleaning means and the release agent coating means, and therefore, it is difficult to bite, and therefore it is difficult to wear. . In addition, since the contact angle is controlled so that the release agent applied to the release layer is not repelled, the toner resin or the like directly touches the release layer to cause an offset or hot melt adhesive. Thus, the recording material does not wrap around the fixing roller.

  Further, when a release agent is applied to the release layer of the fixing roller 1 in this embodiment, the oil component is held in the heat-resistant resin portion, and the offset prevention coating layer can exhibit stable non-adhesiveness over a long period of time. Does not adhere.

  The fixing method of the present invention is to fix the electrophotographic image by supplying a release agent to the surface of the release layer using the fixing device, and the other fixing method of the present invention is the fixing device. Is used to clean the surface of the release layer and fix the electrophotographic image.

  In the fixing device of the present invention, it is preferable that the Martens hardness HM of the member in contact with the fixing member is smaller than the value of the heat resistant resin at a temperature from room temperature to the temperature of the release layer at the time of fixing. .

  In order to separate the recording material from the fixing member, if the Martens hardness HM of the member abutted on the fixing member is smaller than the heat resistant resin in the release layer at the temperature at the time of fixing, the release layer is larger than the case where it is larger. Since it is more difficult to deform even when pressed by the abutting member, the fixing member is less likely to bite into the release layer and wear of the release layer is very unlikely. For example, when the member that contacts the fixing member is a recording material separation claw and the heat-resistant resin of the release layer is polyetherimide (PEI), the recording material separation claw is formed of a material such as PEEK. Of course, the member abutting on the fixing member is not limited to the recording material separation claw, but may be another shape such as a blade.

  Further, depending on the fixing device, when the surface of the release layer is heated from room temperature to a temperature at which fixing can be performed, the surface temperature of the pressure member in contact with the fixing member is quickly stabilized at a uniform temperature. There is a case where heating is performed while rotating. In this case, a member abutting on the fixing member is used to separate the recording material from the fixing member even at a temperature from room temperature to the temperature of the release layer at the time of fixing. If the Martens hardness HM is smaller than the heat resistant resin in the release layer, it will be more difficult to deform even if the release layer is pressed by the corresponding contact member, so that the corresponding contact member is separated. It becomes difficult to bite into the mold layer. Therefore, it can be made harder to wear. For example, when the member that contacts the fixing member is a recording material separation claw and the heat-resistant resin of the release layer is PEI or PI, the recording material separation claw is formed of a material such as PEEK.

  The image forming apparatus of the present invention is provided with the fixing device.

  According to the image forming apparatus of the present invention, since the usable period of the fixing member is greatly increased, resource saving is achieved, and it is possible to reduce the load on the environment which has been regarded as a problem in recent years.

  Using the release layer shown in Table 5, the charging potential was measured using MF4570 manufactured by Ricoh Co., Ltd., and the offset property, paper jam, abrasion resistance, release of heat resistant resin, and temperature distribution were evaluated. .

  Here, the mold release layer was formed in the thickness of 30 micrometers on the upper part of the aluminum cylindrical core metal as a heat resistant base material. The temperature of the fixing member at the time of fixing was set to 180 ° C.

  The charging potential was determined by measuring the surface of the fixing roller during paper passing with a Model 347 manufactured by Trek, a surface potential meter, and calculating the time average. The offset property was evaluated in four stages by copying 100 ruled line charts continuously (good → ◎ → ○ → Δ → × → bad). For paper jam, 10,000 solid black charts were copied continuously, and the number of paper jams in the fixing unit was evaluated in four stages (good → ◎ → ○ → Δ → × → bad). Abrasion resistance was evaluated in four stages according to the amount of surface scraping (good → ◎ → ○ → Δ → × → bad). Desorption of the heat-resistant resin was continuously passed through and evaluated in four stages according to the amount of holes due to desorption (good → ◎ → ○ → Δ → × → bad). For the temperature distribution, a thermistor was attached to the center and both ends of the fixing roller in the axial direction, and the temperature difference was measured and evaluated in four stages (temperature difference small → ◎ → ○ → Δ → × → large).

  Table 5 shows the results of measuring the charging potential and the results of evaluation of offset property, paper jam, abrasion resistance, heat-resistant resin detachment, and temperature distribution.

  From the results of Table 5, Examples 1 to 5 were all excellent in offset property, paper jam, abrasion resistance, release of heat-resistant resin and temperature distribution. On the other hand, Comparative Examples 1-3 were inferior to Examples 1-5 about offset property, paper jam, abrasion resistance, and temperature distribution.

It is a figure which shows the structure of one Embodiment of the method of measuring Martens hardness HM in this invention. It is a figure which shows an example of the composite powder which melted one part or all part which comprises the outer shell which consists of heat resistant resins. It is a figure which shows an example of the composite powder which melt-coupled the particle | grains of FEP. It is a figure which shows an example of the surface and cross section of the release layer for the conventional abrasion resistance improvement. It is a figure which shows another example of the surface and cross section of the release layer for the conventional abrasion resistance improvement. It is a figure which shows an example of the surface and cross section of a mold release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of the mold release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows another example of the surface and cross section of a release layer in the fixing member of this invention. It is a figure which shows an example of the mold release layer cross section in the fixing member of this invention. It is a figure which shows another example of the mold release layer cross section in the fixing member of this invention. 1 is a schematic cross-sectional view showing an embodiment of a fixing device of the present invention. It is a schematic sectional drawing which shows other one Embodiment of the fixing device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 2a Silicon rubber layer 2b Core metal 3 Heat source 4 Temperature detection element 5 Roller body 5a Core metal 5b Oil impregnation heat-resistant felt 6 Recording material separation claw 7 Spring N Holding pressure part P Recording material T Unfixed Toner image

Claims (17)

A fixing member having a heat resistant substrate and a release layer formed on the heat resistant substrate,
The release layer is composed of particles containing a fluororesin and a heat resistant resin that surrounds the outside of the particles containing the fluororesin and has a Martens hardness HM at a temperature of 15 ° C. to 250 ° C. that is greater than the value of the fluororesin. A fixing member, wherein a composite powder including an outer shell is assembled and then formed into a film.   The fixing member according to claim 1, wherein the release layer is obtained by melting part or all of the particles constituting the outer shell made of the heat resistant resin.   The fixing member according to claim 1, wherein a thickness of the outer shell made of the heat resistant resin is smaller than a particle diameter of the toner.   4. The fixing member according to claim 1, wherein a layer made of only a fluororesin is laminated on the surface of the release layer. 5.   The fixing member according to claim 1, wherein the particles containing the fluororesin contain a conductive filler.   The fixing member according to claim 1, wherein the particles containing the fluororesin contain a thermally conductive filler.   The fixing member according to claim 1, wherein an elastic layer is provided between the heat-resistant substrate and the release layer.   8. The fixing member according to claim 1, wherein a part of the surface of the heat resistant resin is bonded to the heat resistant base material or the elastic layer. 9. Fixing member.   9. The fixing according to claim 1, wherein the fixing member includes an adhesive layer provided between the release layer and the heat-resistant base material or the elastic layer. Element.   In the fixing member, the resin existing on the surface of the heat-resistant substrate and the outer shell made of the heat-resistant resin of the release layer are the same type of resin, and the release layer is the heat-resistant substrate. The fixing member according to claim 1, wherein the fixing member is formed directly on the fixing member.   A fixing member according to claim 1, and a member abutting on the fixing member for separating the recording material on which the toner is fixed from the fixing member. Fixing device.   The fixing device according to claim 11, wherein the fixing device further includes means for supplying a release agent to the surface of the release layer.   A fixing method comprising fixing the electrophotographic image by using the fixing device according to claim 12 and supplying a release agent to the surface of the release layer.   The fixing device according to claim 11, wherein the fixing device further includes means for cleaning a surface of the release layer.   A fixing method comprising: fixing the electrophotographic image by cleaning the surface of the release layer using the fixing device according to claim 14.   15. The fixing device according to claim 11, wherein a Martens hardness HM at a temperature of 15 ° C. to 250 ° C. of a member abutting on the fixing member is smaller than a value of the heat resistant resin. The fixing device according to any one of the items.   An image forming apparatus comprising the fixing device according to any one of claims 11, 12, 14, and 16.

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