JP4351031B2 - Endless belt - Google Patents

Description

  The present invention relates to an endless belt used for a fixing belt or the like used in a fixing unit that fixes a toner image transferred onto a transfer material such as transfer paper by heating in an apparatus such as an electrophotographic copying machine, a facsimile machine, or a printer. .

  In an image forming apparatus such as an electrophotographic copying machine, a facsimile machine, and a printer, toner on a transfer material such as transfer paper is heated and melted and fixed on the transfer paper at the final stage of printing and copying. As a fixing method, a heat fixing method is generally used, and a heat roller fixing method has been widely used. In this heat roller fixing method, a toner image is formed between a pair of rollers each having a heat roller having a heat heater inside and coated with a rubber or resin having a good releasability and a rubber roller. The toner is heated and melted by passing through the transfer paper, and the toner is fused on the transfer paper. This heat roller fixing method is suitable for speeding up because the entire heat roller is maintained at a predetermined temperature, but has the disadvantage that the waiting time is long. That is, at the start of the operation of the apparatus, a time for heating the heat roller to a predetermined temperature is required, so that a waiting time is generated from when the power is turned on until the operation becomes possible. And since the whole heat roller must be heated, power consumption is also large.

  Therefore, in recent years, an endless belt fixing method has been proposed in which the toner on the transfer paper is heated by a heater via a film-like endless belt. In this endless belt fixing method, a fixing belt and a rubber roller are brought into pressure contact with each other, a transfer paper on which a toner image is formed is passed between them and heated by a heater, and the toner is fused and fixed on the transfer paper. In this fixing method, since the heater is substantially directly heated only through a thin film belt, the heating unit reaches a predetermined temperature in a short time, and the waiting time after power-on can be greatly reduced. it can. Furthermore, since only a necessary part is heated, there is an advantage that power consumption is low.

  However, the endless belt fixing method employs a heating method using a heater, similar to the heat roller fixing method, so the heat dissipation is still large and the heater temperature is considerably higher than the temperature required for fixing for sufficient fixing. It is necessary to set a high temperature and slow down the passing speed of the transfer paper to give a sufficient fixing time. Therefore, recently, an electromagnetic induction heating method has been adopted in which a heat generation layer containing metal is provided on a film-like endless belt, eddy current is generated in the heat generation layer by electromagnetic induction, and heating is performed by Joule heat generated thereby. (For example, refer to Patent Document 1). That is, this heat generating layer becomes a heat generating element and is heated.

In the case of the heating method using a heater, the heater temperature must be raised to a temperature considerably higher than the fixing temperature in order to realize high-speed copying. On the other hand, if the electromagnetic induction heating method is used, a heating element (heating layer) ) Is close to the fixing portion, the heating element temperature can be made substantially the same as the fixing temperature. In addition, since the heat is generated by electromagnetic induction, it is possible to shorten the time until the temperature rises as compared with the prior art.
JP-A-9-146392

  However, when heating by the electromagnetic induction heating method is performed for a long time, the metal contained in the heat generation layer may be deteriorated by being oxidized or sulfided by oxygen, sulfur, etc. in the air. When the metal contained in the heat generating layer is changed to metal oxide or metal sulfide by oxidation or sulfurization, the characteristics of the fixing belt are deteriorated, and the fixing is caused by the influence of these metal oxide or metal sulfide. There is a problem that the resin constituting the belt is decomposed and the function of the fixing belt is lowered.

  Accordingly, the present invention has been made to solve the above-described conventional problems, and provides an endless belt in which characteristics and functions of a fixing belt and the like are not deteriorated even when heating by an electromagnetic induction heating method is performed for a long period of time. is there.

  The present invention provides an annular endless belt having a heat generating layer containing a metal, wherein the metal has a modified layer on at least a part of its surface.

  Since the endless belt of the present invention includes a modified layer on at least a part of the surface of the metal included in the heat generating layer, oxidation and sulfurization of the metal are suppressed, and heating by an electromagnetic induction heating method is performed for a long time. Also, it is possible to prevent deterioration of characteristics and functions of the fixing belt and the like.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an example of the endless belt of the present invention will be described. FIG. 1 is a cross-sectional view showing an example of an endless belt according to the present invention, and FIG. 2 is an enlarged cross-sectional view of an AA portion of FIG. The endless belt 1 according to the present embodiment includes a release layer 2 made of a fluororesin as an outermost layer and an outer surface of the endless belt 1, a first adhesive layer 3, and a first adhesive layer 3 next to the release layer 2. Next, the elastic layer 4, the second adhesive layers 5a and 5b comprising two layers next to the elastic layer 4, and the second adhesive layer 5b are followed by the support layer 6 (first support layer 6a and second support layer). 6b, a third support layer 6c, a fourth support layer 6d) and a heat generating layer 7 (first heat generating layer 7a, second heat generating layer 7b, and third heat generating layer 7c).

  First, the release layer 2 will be described. The release layer 2 is made of a fluororesin and has a molding surface on the outer surface. Since the endless belt 1 of the present embodiment includes the release layer 2 made of a fluororesin in the outermost layer, the endless belt 1 has excellent release properties. Furthermore, since the outer surface of the release layer 2 is formed by a molding surface, the outer surface of the release layer 2 is smooth, and has better release properties than a release layer formed by a molding free surface. Have. Here, the molding surface refers to the surface in contact with the mold during molding. The molding free surface means a surface that is not in contact with the mold during molding.

  The fluororesin used for the release layer 2 is made of tetrafluoroethylene polymer (PTFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), and fluorinated ethylene-propylene copolymer (PFEP). It is preferably at least one selected from the group. Endless belts using these fluororesins as the release layer 2 are excellent in terms of fixability, surface hardness, surface conductivity, surface release properties, surface roughness, durability, and film thickness freedom. In particular, the toner has excellent fixability, releasability and durability of the release layer. In addition, a conductive material, an abrasion resistant material, and a good heat conductive material can be added as a filler to the fluororesin as necessary.

  Moreover, it is preferable that the thickness of the mold release layer 2 is 5-50 micrometers. If it is this thickness range, the abrasion durability of a mold release layer is favorable, and the mold release layer 2 does not harden | cure while maintaining high surface hardness. In particular, the range of 15 to 25 μm is more preferable.

  Next, the elastic layer 4 will be described. Since the endless belt 1 of this embodiment includes the elastic layer 4 between the outermost layer and the innermost layer, the endless belt 1 has excellent fixing properties. The elastic layer 4 is preferably made of silicone rubber having a JIS hardness of A1 to A80 degrees. Within this JIS hardness range, it is possible to prevent poor toner fixability while preventing a decrease in strength and poor adhesion of the elastic layer 4. Specific examples of the silicone rubber include one-component, two-component or three-component or more silicone rubber, LTV type, RTV type or HTV type silicone rubber, condensation type or addition type silicone rubber. .

  Moreover, it is preferable that the thickness of the elastic layer 4 is 30-2000 micrometers. If it is this thickness range, heat insulation can be restrained low, maintaining the elastic effect of the elastic layer 4, and an energy saving effect can be exhibited. In particular, the range of 100 to 300 μm is more preferable.

  Next, the support layer 6 will be described. Since the endless belt 1 of the present embodiment includes the support layer 6 on the inner side, the endless belt 1 has excellent strength. In the present embodiment, the support layer 6 includes four layers of the first support layer 6a, the second support layer 6b, the third support layer 6c, and the fourth support layer 6d, but is not limited to four layers, and is a single layer. It may be. The support layer 6 is preferably made of a heat resistant synthetic resin. This is because the fixing belt or the like is usually heated to about 200 ° C. Therefore, the heat resistant synthetic resin is preferably polyimide (PI) or polyamideimide (PAI). This is because these resins are excellent in strength, heat resistance, price and the like.

  Moreover, it is preferable that each thickness of the support layers 6a-6d is 5-100 micrometers. If it is this thickness range, while maintaining the strength and wear durability of the support layer, the heat insulation can be kept low without lowering the flexibility, and the energy saving effect can be exhibited. In particular, the range of 5 to 60 μm is more preferable. Further, the thicknesses of the support layers 6a to 6d may be equal or different.

  Next, the heat generating layer 7 will be described. Since the endless belt 1 of the present embodiment is provided with a heat generating layer 7 containing a metal inside thereof, the metal can be heated by electromagnetic induction or the like, thereby enabling the endless belt 1 to be heated more directly. Thus, the waiting time after power-on can be shortened and energy can be saved. In the present embodiment, the heat generating layer 7 is composed of three layers of the first heat generating layer 7a, the second heat generating layer 7b, and the third heat generating layer 7c, but is not limited to three layers, and may be a single layer. In addition, although the position where the heat generating layer 7 is provided is not limited, in the present embodiment, the heat generating layers 7a to 7c are alternately stacked with the support layers 6a to 6d. Thus, by using a multilayer structure, the heating effect by electromagnetic induction etc. can be heightened more.

  Although the heat generating layer 7 can be formed as a single layer made of only a metal that is a heat generating element, a material in which a filler made of a metal is mixed in a heat resistant synthetic resin is preferably used. The heat resistant synthetic resin is preferably polyimide (PI) or polyamideimide (PAI). This is because these resins are the same resins that can be used as the support layer 6 and are excellent in strength, heat resistance, price, and the like.

  Moreover, it is preferable that each thickness of the heat-generation layers 7a-7c is 3-35 micrometers. If it is this thickness range, the heating effect by electromagnetic induction etc. can be heightened more. In particular, the range of 5 to 30 μm is more preferable. Moreover, the thickness of each heat generating layer 7a-7c may be equal or different.

  In addition, as a metal contained in the heat generation layer 7 and generating heat by electromagnetic induction or the like, copper (Cu), aluminum (Al), nickel (Ni), iron (Fe), stainless steel (SUS), tin (Sn), zinc (Zn), lead (Pb), gold (Au), silver (Ag), platinum (Pt), or the like can be used, but silver (Ag) is most preferable because of its excellent heat generation performance. Moreover, when using these metals as a heat_generation | fever filler, the heat_generation | fever filler which consists of a several kind of metal can also be mixed and used.

  When the metal is used as a heat-generating filler, the mixing ratio of the heat-generating filler and the heat-resistant synthetic resin is heat-resistant synthetic resin: heat-generating filler = 1 part by weight: 99 parts by weight to 80 parts by weight: 20 parts by weight. Preferably, heat-resistant synthetic resin: exothermic filler = 10 parts by weight: 90 parts by weight to 50 parts by weight: 50 parts by weight.

  In the case where the heat generating layer 7 is not provided independently, at least one layer of the release layer 2, the support layer 6 and the elastic layer 4 may contain a metal filler so as to serve as the heat generating layer.

  The metal contained in the heat generating layer 7 and generating heat by electromagnetic induction or the like has a modified layer on at least a part of its surface. Thereby, even if it heats by an electromagnetic induction heating system for a long period, it can control that the metal contained in exothermic layer 7 is oxidized and sulfided by oxygen, sulfur, etc. in the air, and deteriorates.

  Here, the modified layer means a layer that suppresses the reaction between the metal and oxygen, sulfur, etc. in the air, and more specifically, the metal is an organic compound having a thione group or a mercapto group, And a modified layer formed by reacting with at least one organic compound selected from nitrogen-containing heterocyclic compounds.

  The organic compound having a thione group or a mercapto group is particularly preferably a nitrogen-containing heterocyclic compound having a thione group or a mercapto group. This compound may have two or more thione groups or mercapto groups. Examples of the nitrogen-containing heterocycle of this compound include imidazole, imidazoline, thiazole, thiazoline, oxazole, oxazoline, pyrazoline, triazole, thiadiazole, oxadiazole, tetrazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine and the like.

  Specific examples of the compound include 2-mercapto-4-phenylimidazole, 2-mercapto-1-benzylimidazole, 2-mercapto-1-butyl-benzimidazole, 1,3-dibenzyl-imidazolidine-2-thione, 2-mercapto-4-phenylthiazole, 3-butyl-benzothiazoline-2-thione, 3-dodecyl-benzothiazoline-2-thione, 2-mercapto-4,5-diphenyloxazole, 3-pentyl-benzoxazoline-2 -Thione, 1-phenyl-3-methylpyrazolin-5-thione, 3-mercapto-4-allyl-5-pentadecyl-1,2,4-triazole, 3-mercapto-5-nonyl-1,2,4-triazole 3-mercapto-4-acetamido-5-heptyl-1,2,4-tria 3-mercapto-4-amino-5-heptadecyl-1,2,4-triazole, 2-mercapto-5-phenyl-1,3,4-thiadiazole, 2-mercapto-5-n-heptyl-oxa Diazole, 2-mercapto-5-n-heptyl-oxadiazole, 2-mercapto-5-phenyl-1,3,4-oxadiazole, 2-heptadecyl-5-phenyl-1,3,4-oxa Diazole, 5-mercapto-1-phenyl-tetrazole, 3-mercapto-4-methyl-6-phenyl-pyridazine, 2-mercapto-5,6-diphenyl-pyrazine, 2-mercapto-4,6-diphenyl-1 , 3,5-triazine, 2-amino-4-mercapto-6-benzyl-1,3,5-triazine, 4-dibutylamino-2,6-dimethyl Mercapto-1,3,5-triazine, 4-ethoxy-2,6-dimercapto-1,3,5-triazine, and 4-methyl-2,6-dimercapto-1,3,5-triazine. Among these, a triazine compound having two mercapto groups is particularly preferable.

  The nitrogen-containing heterocyclic compound is preferably at least one compound selected from imidazole compounds, benzimidazole compounds, triazole compounds, benzotriazole compounds, thiadiazole compounds, oxadiazole compounds, and tetrazole compounds.

The metal and the organic compound can be reacted by dissolving the organic compound in an alkaline aqueous solution and immersing the metal in the solution. The concentration of the organic compound in this solution is suitably about 0.05 to 10 g, preferably 0.5 to 5 g, per 1 dm ³ of the solution.

  Next, the first adhesive layer 3 will be described. The first adhesive layer 3 is an adhesive layer disposed between the release layer 2 and the elastic layer 4. The first adhesive layer 3 is preferably made of a fluororubber primer. Specifically, VDF-HFP, VDF-HFP-TFE, VDF-PFP, VDF-PFP-TFE, VDF-PFMVE- Fluororubber such as TFE or VDF-CTFE can be used.

  Moreover, it is preferable that the thickness of the 1st contact bonding layer 3 is 1-20 micrometers. If the thickness is within this range, coating unevenness does not occur, and there is no variation in adhesion, and coating is easy. In particular, the range of 2 to 10 μm is more preferable.

  Next, the second adhesive layer 5 will be described. The thickness of the second adhesive layer 5 is preferably 2 to 10 μm. If it is this thickness range, adhesiveness will become more favorable and application | coating will also become easy.

  Moreover, it is preferable that the 2nd contact bonding layer 5 consists of two layers of the primer layer 5a for silicone rubber of thickness 1-5 micrometers, and the fluororubber primer layer 5b of thickness 1-5 micrometers. This is because the adhesion between the elastic layer 4 and the support layer 6 can be made stronger by adopting a two-layer structure. Here, as a material of the primer layer 5a for silicone rubber, silane coupling agents such as vinyl silane, acrylic silane, epoxy silane, and amino silane can be used. The material of the fluororubber primer layer 5b is fluorine such as VDF-HFP, VDF-HFP-TFE, VDF-PFP, VDF-PFP-TFE, VDF-PFMVE-TFE, VDF-CTFE, etc. Rubber can be used.

  Moreover, a conductive material, a good heat conductive material, and a tensile strength reinforcing material are added as fillers to the elastic layer 4, the support layer 6, the first adhesive layer 3, and the second adhesive layer 5 as necessary. You can also.

  Next, an example of the manufacturing method of the endless belt of this invention is demonstrated. FIG. 3 is a cross-sectional view for explaining an example of the method of manufacturing an endless belt according to the present invention, and FIG. 4 is an enlarged cross-sectional view of the main part of the BB part of FIG. In the manufacturing method of the endless belt according to the present embodiment, the release layer 2 made of a fluororesin is applied to the annular outer peripheral surface of the mold 8, the first adhesive layer 3 is applied on the release layer 2, and then After these are fired at a predetermined temperature, the elastic layer 4 is applied on the first adhesive layer 3, fired at the predetermined temperature, and then the second adhesive layer 5a composed of two layers on the elastic layer 4 5b is applied and dried. Thereafter, the first support layer 6a, the first heat generation layer 7a, the second support layer 6b, the second heat generation layer 7b, the third support layer 6c, the third heat generation layer 7c, and the fourth support are formed on the second adhesive layer 5b. The layers 6d are applied in this order and fired at a predetermined temperature.

  Finally, as shown in FIG. 5, the endless belt 1 is turned away from the mold 8 while turning over. Thus, as shown in FIG. 1, the outermost layer has a release layer 2 made of a fluororesin and the outer surface is a molding surface, the innermost layer has a support layer 6 and a heat generating layer 7, and the outermost layer and The annular endless belt 1 of this embodiment having the elastic layer 4 as an intermediate layer between the innermost layers is completed. In FIG. 5, the adhesive layer is omitted.

  The firing temperature of the release layer 2 is preferably 330 to 430 ° C. Within this temperature range, the moldability of the release layer 2 is good and the release layer 2 does not deteriorate.

  Moreover, it is preferable that the calcination temperature of the elastic layer 4 is 150-300 degreeC. Within this temperature range, deterioration and hardening of the elastic layer 4 do not occur while preventing the volatile component of the elastic layer 4 from remaining and insufficient strength.

  Furthermore, it is preferable that the calcination temperature of the support layer 6 (6a-6d) and the heat generating layer 7 (7a-7c) is 150-300 degreeC. Within this temperature range, the strength of the support layer 6 and the heat generating layer 7 is not lowered, and the elastic layer 4 is not deteriorated.

  In addition, as a shaping | molding die used by this embodiment, pipe-shaped shaping | molding molds, such as a product made from brass, stainless steel, iron, and aluminum, or a glass-made shaping die can be used.

  Hereinafter, the present invention will be described in more detail using examples and comparative examples.

(Example 1)
<Preparation of heat generation layer material and preparation of heat generation layer sample>
A heat generation layer material was prepared by mixing silver flakes having an average particle size of 9 μm and polyimide varnish (“RC-5057” manufactured by IST). The mixing ratio of the polyimide varnish and the silver flakes was polyimide varnish: silver flakes = 1: 1 by volume.

  Next, this heat generation layer material was apply | coated on the glass substrate, and it baked at 250 degreeC for 1 hour, and produced the heat generation layer sample.

<Preparation of treatment solution>
As an organic compound, 2 g of 2-dibutylamino-4,6-dimercapto-s-triazine, 50 g of diethylene glycol, 4 g of sodium hydroxide, 2.5 g of dipotassium hydrogen phosphate and 20 g of 85% phosphoric acid were prepared. These were dissolved in 1 dm ³ of water to prepare a treatment solution.

<Processing of heat generation layer sample>
After the heat generating layer sample was immersed in the treatment solution for 2 minutes, the heat generation layer sample was taken out of the treatment solution, washed with water, and then naturally dried to prepare a processed heat generation layer sample.

  In addition, since silver flakes are mixed in the polyimide varnish, the sample is in a porous state, and the treatment liquid reaches the silver flakes contained in the polyimide varnish.

  For comparison, an untreated exothermic layer sample was prepared in the same manner as the treated exothermic layer sample except that it was not treated with the treatment liquid.

<Confirmation of treatment effect>
The treated exothermic layer sample and the untreated exothermic layer sample were left in a hot air circulating furnace at 250 ° C. for 100 hours, and then the surface of each exothermic layer was observed. As a result, no significant change was observed in the treated exothermic layer sample, whereas in the untreated exothermic layer sample, the exothermic layer turned brownish. This is considered to be because, in the untreated heat generation layer sample, silver flakes contained in the heat generation layer were oxidized by oxygen in the air, and the oxidized silver became a hydrolysis catalyst and decomposed the polyimide varnish.

(Example 2)
<Processing of heating element metal>
As the heating element metal, silver flakes having an average particle diameter of 9 μm were used. A modified layer was formed on the surface of this silver flake by the following treatment.

First, 2 g of 2-dibutylamino-4,6-dimercapto-s-triazine, 50 g of diethylene glycol, 4 g of sodium hydroxide, 2.5 g of dipotassium hydrogen phosphate and 20 g of 85% phosphoric acid are dissolved in 1 dm ³ of water as an organic compound. Thus, a treatment liquid was prepared.

Next, 50 g of silver flakes were immersed in 1 dm ³ of the treatment liquid to react the silver flakes with the organic compound, thereby forming a modified layer on the surface of the silver flakes. Thereafter, the silver flakes were washed with water and dried.

<Preparation of heat generation layer material>
The heat-generating layer material was prepared by mixing the silver flakes subjected to the above treatment and polyimide varnish (“RC-5057” manufactured by IST). The mixing ratio of the polyimide varnish and silver flakes was polyimide varnish: silver flakes = 1: 2 in volume ratio.

<Production of endless belt>
A forming die was prepared by mirror polishing the outer peripheral surface of a stainless steel (SUS304) pipe having an inner diameter of 60 mm and a thickness of 3 mm. On the outer peripheral surface of the mold, a tetrafluoroethylene polymer imparted with conductivity as a release layer (“ED-4839BD” manufactured by Daikin) was applied to a thickness of 35 μm, and fluorine on the first adhesive layer was applied to the outer surface. Fluororubber latex (“GL-252” manufactured by Daikin) was applied as a rubber primer to a thickness of 10 μm, dried at 100 ° C. for 15 minutes, and then baked at 380 ° C. for 15 minutes. The thickness of the release layer after firing was 20 μm.

  Next, after cooling the mold to room temperature, silicone rubber (“KE-1241” manufactured by Shin-Etsu Silicon) was applied as an elastic layer and baked at 250 ° C. for 30 minutes. The thickness of the elastic layer after firing was 200 μm, and the JIS hardness was A10 degrees.

  Subsequently, a silicone rubber primer (“GLP-103SR” made by Daikin) is used as the first layer of the second adhesive layer on the outer surface, and a fluororubber primer (“DPA-362 made by Daikin” is used as the second layer of the second adhesive layer. “)” Was applied to a thickness of 2 μm and dried.

  Next, a polyimide varnish (“RC-5057” manufactured by I.S.T.) is applied as a support layer on the outer surface, and the above-described heat generation layer material is applied as a heat generation layer thereon, and the coating is applied alternately in this order. Repeatedly, as shown in FIG. 4, the support layers 6a to 6d and the heat generating layers 7a to 7c were applied and dried, followed by baking at 250 ° C. for 30 minutes. Each thickness of the exothermic layer after firing was 30 μm, and each thickness of the support layer was 60 μm.

  Finally, after cooling the mold to room temperature, the produced annular product was removed from the mold while turning over to obtain an endless belt of Example 1 of the present invention.

(Comparative Example 1)
A conventional endless belt of Comparative Example 1 was obtained in the same manner as in Example 2 except that the treatment for forming the modified layer on the surface of the silver flakes was not performed.

<Measurement of peel strength of endless belt>
The endless belts of Example 2 and Comparative Example 1 were placed in a hot air circulating furnace at 250 ° C., and the peel strength (interlayer adhesion) between the support layer and the heat generating layer was measured for each elapsed time. First, the end portions of the endless belt before being put into the hot air circulating furnace were cut into ring shapes each having a width of 1 cm, and then cut in one width direction to produce a strip-shaped test piece. Next, after forcibly peeling the support layer 6a and the heat generating layer 7a at the end of the test piece by about 20 mm, as shown in FIG. 6, the peeling end is pulled in the direction of 180 °, respectively. The strength of the peeling between 6a and the heat generating layer 7a was measured using a tensile tester “Autograph AGS-H” manufactured by Shimadzu to obtain the peeling strength. Then, the remaining endless belt is put into a hot-air circulating furnace, and after a lapse of a certain time, a test piece is prepared from the endless belt in the same manner. The peel strength was measured. Hereinafter, the peel strength of the test piece was repeatedly measured in the same manner. In FIG. 6, 2 is a release layer, 3 is a first adhesive layer, 4 is an elastic layer, 5a is a first layer of a second adhesive layer, and 5b is a second layer of a second adhesive layer. .

  The result is shown in FIG. In FIG. 7, the peel strength before being left in the hot air circulating furnace is 100% (reference value), and the peel strength after each elapsed time is expressed as a percentage of the reference value. As is apparent from FIG. 7, the endless belt of Example 2 was able to maintain the peel strength up to 75% even after 265 hours had elapsed. In contrast, in the endless belt of Comparative Example 1, the peel strength decreased to 12% after 50 hours.

  The peel strength was measured under accelerating conditions that were stricter than the actual machine conditions when the endless belt was used as a fixing belt for a copying machine.

<Measurement of weight loss by thermobalance>
The heat generation layer material used in Example 2 was prepared as Material A, the heat generation layer material used in Comparative Example 1 as Material B, and only the polyimide varnish used in Example 2 as Material C. Next, each material was applied on a glass substrate with a thickness of 20 μm and baked at 250 ° C. for 1 hour. Next, a specified amount of each material was scraped from the glass substrate to prepare a sample.

  Next, each of these samples was placed on a thermobalance, heated to 250 ° C., and the weight loss rate (%) was measured. The result is shown in FIG. In FIG. 8, each sample was heated from room temperature to 250 ° C. and then maintained at 250 ° C., and the elapsed time and the weight reduction rate (%) of the sample were measured. As is apparent from FIG. 8, the weight loss rate of the materials A and C was 1% or less even after 140 minutes. On the other hand, the weight reduction rate of the material B became 3% or more after 140 minutes.

  As described above, the endless belt of the present invention includes a modified layer on at least a part of the surface of the metal contained in the heat generating layer, so that oxidation and sulfurization of the metal are suppressed and heating by an electromagnetic induction heating method is performed. Even if it is performed for a long period of time, deterioration of characteristics and functions can be prevented, and it can be used for fixing belts of electrophotographic copying machines, facsimiles, printers and the like.

It is sectional drawing which shows an example of the endless belt of this invention. It is an expanded principal part sectional drawing of the AA part of FIG. It is sectional drawing explaining an example of the manufacturing method of the endless belt of this invention. It is an expanded principal part sectional drawing of the BB part of FIG. It is principal part sectional drawing of the state made to detach | leave from a shaping | molding die, turning over an endless belt. It is a side view explaining the measuring method of peeling strength. It is a figure which shows the relationship between peeling strength and elapsed time. It is a figure which shows the relationship between a weight decreasing rate, temperature, and elapsed time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endless belt 2 Release layer 3 1st contact bonding layer 4 Elastic layer 5 2nd contact bonding layer 5a 1st layer of 2nd contact bonding layer 5b 2nd layer of 2nd contact bonding layer 6 Support layer 6a 1st support layer 6b 2nd support layer 6c 3rd support layer 6d 4th support layer 7 Heat generation layer 7a 1st heat generation layer 7b 2nd heat generation layer 7c 3rd heat generation layer 8 Mold

Claims (9)

An annular endless belt provided with a heat generation layer in which a filler made of silver that generates heat by electromagnetic induction is mixed in polyimide (PI) or polyamideimide (PAI),
The silver has a modified layer on at least a part of its surface ;
An endless belt in which the modified layer is formed by reacting the silver with at least one organic compound selected from an organic compound having a thione group or a mercapto group, and a nitrogen-containing heterocyclic compound .   The endless belt according to claim 1, further comprising a release layer, a support layer, and an elastic layer disposed between the release layer and the support layer. The endless belt according to claim 1 or 2 , wherein the organic compound having a thione group or a mercapto group is a nitrogen-containing heterocyclic compound having a thione group or a mercapto group. The nitrogen-containing heterocyclic ring of the nitrogen-containing heterocyclic compound having a thione group or a mercapto group is imidazole, imidazoline, thiazole, thiazoline, oxazole, oxazoline, pyrazoline, triazole, thiadiazole, oxadiazole, tetrazole, pyridine, pyrimidine, pyridazine, The endless belt according to claim 3 , which is pyrazine or triazine. The endless compound according to claim 1 or 2 , wherein the nitrogen-containing heterocyclic compound is at least one compound selected from an imidazole compound, a benzimidazole compound, a triazole compound, a benzotriazole compound, a thiadiazole compound, an oxadiazole compound, and a tetrazole compound. belt.   The endless belt according to claim 2, wherein the heat generating layer is included in the support layer.   The endless belt according to claim 2, wherein the support layer includes at least one selected from polyimide (PI) and polyamideimide (PAI).   The release layer is at least one selected from tetrafluoroethylene polymer (PTFE), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), and fluorinated ethylene-propylene copolymer (PFEP). The endless belt according to claim 2, comprising:   The endless belt according to claim 2, wherein the elastic layer includes a silicone rubber having a JIS hardness of A1 to A80 degrees.

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