JP2000181257A - Endless belt and image fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt having heat resistance, made excellent in dimensional accuracy even under high temperature environment, excellent in flexure fatigue life, further good in heat conductivity and suitable as an image fixing belt for a copying machine or a printer, and an image fixing device equipped with the endless belt. SOLUTION: As for this endless belt 1 having structure that heat resistant film made of high polymer material which is not melted and decomposed at <350 deg.C is stuck and laminated by heat resistance resin film thickness is 2 to 30 μm, resin thickness is 1 to 20 μm, belt thickness is 50 to 300 μm, the volume percentage of the film in the belt is 55 to 95%, and the film is laminated and wound at least twice, then an interlayer peeling part having >=1 mm length is not caused even in the case of holding the belt at 200 deg.C for one minute. Such an endless belt and the image fixing device equipped with the endless belt are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless belt which can be used in a high-temperature environment and an image fixing device using the same.

[0002]

2. Description of the Related Art In recent years, a large amount of heat-resistant, non-adhesive, and releasable belt materials have been used in image forming apparatuses and industrial machinery. As a material of the belt having such heat resistance and releasability, fluorine belt described in JP-A-5-204255 or JP-A-5-305681, made of aromatic polyimide or other plastic, is used. Resin coated, and Japanese Patent Application Laid-Open No. 5-82
No. 26, a glass fiber cloth coated with a fluororesin and then processed endlessly has been mainly used.

[0003] However, belts made of resin such as polyimide have excellent heat resistance, but are limited in the thickness and performance that can be manufactured because they are manufactured by casting from a polymer solution. It can only be used in very limited fields because it cannot meet the demands. Further, with a fluororesin coated belt having a glass fiber cloth as a core, fluff of the glass fiber is apt to occur with use, and the commercial value of the object to be treated is lost or the life of the belt itself is shortened. In addition, in recent years, while miniaturization and labor saving of devices have been advocated, in combination with a pulley having a small diameter, the life is extremely short in combination with a small-diameter pulley due to the easiness of breaking glass fibers due to bending, and it has not endured practical use.

As a technique for addressing these problems, there has been proposed an attempt to form an endless belt by laminating a film, which has been rarely omitted, in a cylindrical shape. JP-A-7-
JP-A No. 125067 proposes a method for producing a belt in which an aromatic polyamide or polyimide film base material is adhered with a heat-resistant adhesive, but the adhesion to the heat-resistant adhesive layer is insufficient, so that a belt such as a printer is used. When used in a fixing device, it is not sufficient in terms of durability and dimensional accuracy due to its high temperature and high tension environment.

Japanese Patent Application Laid-Open No. Hei 4-269526 discloses a belt in which an aromatic polyamide or polyimide film base material is bonded and laminated with an adhesive. Since the heat resistance of the agent is not always sufficient, and the adhesive strength in a high-temperature use environment is lacking, the life and accuracy of, for example, a belt for an image fixing device used at a high temperature remain unsatisfactory. JP-A-4-30143
The belt specifically disclosed in the example of JP-A No. 9 also has a low volume fraction of the heat-resistant film and lacks adhesive strength in a high-temperature use environment, so that the life and accuracy of the belt remain unsatisfactory. Was.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a belt having high heat resistance, enduring use in a high temperature environment, a long life, high performance and high precision, and an image fixing apparatus using the same. With the goal.

[0007]

The inventor of the present invention has conducted intensive studies on the application technology of the film laminating material to a belt, and as a result, a heat-resistant film is bonded and laminated with a heat-resistant resin to form a specific configuration in a cylindrical shape. For endless belts to be molded into what we have, we are developing technology to secure the adhesive strength between the heat-resistant film and the heat-resistant resin at high temperatures, for example, 200 ° C, and have excellent performance, accuracy, and life in high-temperature use environments. We succeeded in obtaining a belt, devised a specific application of the belt, and reached the present invention.

That is, a first aspect of the present invention is an endless belt having a structure in which heat-resistant films made of a polymer material that does not melt and decompose at a temperature of less than 350 ° C. are bonded to each other by a heat-resistant resin and laminated. The film thickness is 2 to 30 μm, the resin thickness is 1 to 20 μm, the belt thickness is 50 to 300 μm, the volume fraction of the film in the belt is 55 to 95%, and the number of times of film lamination is at least two times, The endless belt according to the second aspect of the present invention is characterized in that even if the belt is maintained at 200 ° C. for 1 minute, no delamination portion having a length of 1 mm or more is generated.
Is a device for heating and fixing a toner image carried on a recording sheet, comprising a heating head and an endless belt moving with the recording sheet, wherein the endless belt does not melt and decompose at a temperature lower than 350 ° C. It has a structure in which heat-resistant films made of materials are bonded and laminated to each other with a heat-resistant resin, and the film thickness is 2 to 30 μm.
m, resin thickness 1 ~ 20μm, belt thickness 50 ~ 300μ
m, and the volume fraction of the film in the belt is 55 to 95.
%, The number of film laminations is at least two times, and 1 mm even when the belt is held at 200 ° C. for 1 minute.
An image fixing device is characterized in that the delamination portion having the above length is not generated.

As the laminated endless belt of the present invention, one having a thickness of 50 to 300 μm is selected. A laminated endless belt having a thickness of less than 50 μm has low rigidity as a belt, and in particular, a flanged roll may be used to secure running stability, or an edge position control (E
Even if PC) is used, these functions may not be sufficiently exhibited. On the other hand, when the laminated endless belt has a thickness exceeding 300 μm, the heat transfer efficiency is reduced, and the belt is not suitable for use in, for example, an image fixing device. The thickness of the laminated endless belt is preferably 70 to 180 μm. As will be described later, one of the preferred embodiments of the present invention is a belt in which a coating layer is provided on the innermost surface or the outermost surface of the laminated endless belt. It should be understood that the total thickness is greater than 300 μm, in which case, for example, about 500 μm is the upper limit.

[0010] The endless belt of the present invention is usually cylindrical and its width is not particularly limited.
It is available in a width, preferably 3 to 500 mm wide. In the endless belt of the present invention, the volume fraction of the heat-resistant film contained therein should be 55 to 95%. If the ratio is less than 55%, the proportion of the heat-resistant film that controls the elastic modulus and strength of the belt is small, so that a load that can be added per unit cross-sectional area cannot be large. Therefore, the traveling performance and the load transmission characteristics, particularly those at high temperatures, are reduced. Then, for example, the endless belt may be deformed or wrinkled after repeated running. On the other hand, if the thickness of the belt is increased in order to cover these disadvantages, the bending fatigue life becomes inferior, which leads to a lack of reliability as an element part of the machine.

Conversely, if the volume fraction of the heat-resistant film exceeds 95%, the thickness of the heat-resistant resin becomes too small to maintain the adhesive strength between the heat-resistant film and the heat-resistant resin, which also has a short fatigue life. You can only get a belt. Further, during lamination molding, bubbles and the like are apt to be generated, which also tends to cause a reduction in the adhesion and a reduction in the life of the belt. The heat-resistant film used in the present invention is made of a polymer material that does not melt and decompose at a temperature lower than 350 ° C.

Examples of such a polymer material include aromatic polyamide, aromatic polyimide, PBI (polyparabenzobisimidazole), PBO (polyparabenzobisoxazole), and PBZ (polyparabenzobisthiazole).
Etc. Aromatic polyamide has heat resistance comparable to aromatic polyimide, high strength compared to other polymer materials,
It is easy to obtain a film with a high elastic modulus and has good adhesiveness, and is suitable as a material for a laminated endless belt.

The aromatic polyamide used in the present invention is:
It is substantially composed of a unit selected from the group consisting of the following constituent units. —NH—Ar ₁ —NH— (1) —CO—Ar ₂ —CO— (2) —NH—Ar ₃ —CO— (3) where Ar ₁ , Ar ₂ and Ar ₃ are at least one aromatic ring And may be the same or different, and representative examples thereof include the following.

[0014]

Embedded image In addition, those in which a part of hydrogen on the ring of these aromatic rings is substituted with a halogen group, a nitro group, an alkyl group, an alkoxy group, or the like are also included. Also, X is -O -, - CH ₂ -,
—SO ₂ —, —S—, and —CO—. In particular, an aromatic polyamide in which 80% by mole or more of all aromatic rings are bonded at the para position has favorable properties as a belt material such as high strength and high elastic modulus, and is used in the film of the present invention. Is preferred. Among them, PPTA (polyparaphenylene terephthalamide) has a small thermal dimensional change,
Most preferable is that a film having high strength can be formed.

The aromatic polyimide used in the present invention is one having at least one aromatic ring and at least one imide group in the repeating unit of the polymer, and is represented by the general formula (2) or (3). is there.

[0016]

Embedded image

[0017]

Embedded imageWhere Ar_FourAnd Ar₆Contains at least one aromatic ring
The two carbonyl groups forming the imide ring are on the aromatic ring
Is bonded to an adjacent carbon atom. This Ar _FourIs good
Derived from aromatic tetracarboxylic acid or its anhydride. Teens
Examples of the table are as follows.

[0018]

Embedded image Wherein Y is, -O -, - CO -, - CH 2 -, - S-,
—SO ₂ — and the like. Ar ₆ is derived from tricarboxylic anhydride or its halide. The following are typical examples.

[0019]

Embedded image Ar ₅ and Ar ₇ contain at least one aromatic ring and are derived from aromatic diamines and aromatic isocyanates. Ar
The following are typical examples of 5 or Ar ₇ .

[0020]

Embedded imageHere, some of the hydrogens on these aromatic rings are converted to halogen
With nitro, nitro, alkyl, or alkoxy groups
Including those that have been done. Z is -O-, -CH _Two−, −
S-, -SO_Two-, -CO- and the like.

In particular, an aromatic polyimide in which 80% or more of Ar ₅ and Ar ₇ are aromatic rings bonded to the para position is preferable for producing a film used in the present invention. The method for producing the heat-resistant film used in the present invention is not particularly limited as long as the requirements for the film defined in the present invention are satisfied, and a production method suitable for each polymer may be adopted.

First, with respect to aromatic polyamides which are soluble in an organic solvent, they are polymerized directly in a solvent, or once a polymer is isolated and then redissolved to form a solution, and then a dry method or a wet method is used. Form a film. Further, those which are hardly soluble in an organic solvent such as PPTA are dissolved in concentrated sulfuric acid or the like to form a solution, and then formed into a film by a dry-wet method or a wet method. On the other hand, with respect to polyimide, a tetracarboxylic anhydride and an aromatic diamine are reacted in an organic solvent to obtain a polyamic acid. Solutions are obtained, and they are formed into a film by a dry method or a wet method.

In the dry process, the solution is extruded from a die,
It is cast on a support such as a metal drum or an endless belt, and the drying or imidization reaction proceeds until the cast solution forms a self-supporting film.
In the wet method, the solution is extruded directly from a die into a coagulating liquid, or cast on a metal drum or an endless belt as in the dry method, and then guided into the coagulating liquid and solidified. Next, these films are washed with solvents and inorganic salts in the films, and then subjected to stretching, drying, heat treatment and the like.

The heat-resistant film used in the present invention contains 0.1.
It is preferable to contain from 05 to 10% by weight of an inorganic compound. In order to make the surface of the film have fine irregularities, the inorganic compound is used in about one step at any step in the above-mentioned production method.
By adding a fine inorganic compound having a size of not more than μm, it can be contained in the film. When the content of the inorganic compound is less than 0.05% by weight, the surface of the film is not sufficiently roughened, the adhesion to the heat-resistant resin tends to be insufficient, and the slip of the film is poor. May be an obstacle in On the other hand, when the content of the inorganic compound exceeds 10% by weight, the mechanical performance of the film is reduced, and the performance of the laminated belt is also reduced. The inorganic compound is preferably contained in the heat-resistant film of 0.1 to 5% by weight, and most of the contained inorganic compound is finely dispersed to a size of about 1 μm or less. It is that you are. As the inorganic compound, usually, SiO ₂ , Ti
O ₂ , ZnO, Al ₂ O ₃ , CaSO ₄ , BaSO ₄ ,
A material that is incompatible with the heat-resistant polymer constituting the film such as CaCO ₃ , carbon black, zeolite, and other metal powders is used.

The thickness of the heat-resistant film used in the present invention needs to be 2 to 30 μm. Thickness 30
When the thickness is larger than μm, the step of the laminate caused by the thickness of the film becomes large, and the uniform running of the belt is impaired. In particular, when the belt is used in an image fixing device, it is difficult to obtain uniform image quality. Is not preferred. On the other hand, when the thickness is less than 2 μm, the number of laminations required to obtain a predetermined thickness of the laminate increases, and the labor required for forming the belt increases, leading to an increase in processing cost. Further, it is not preferable because, during lamination, defects such as wrinkles and bubbles are easily generated between the films. The thickness is particularly preferably from 4 to 25 μm from the viewpoint of workability of handling the film in the endless belt manufacturing process and strength and elastic modulus of the manufactured belt.

The rotation accuracy of the flat belt depends on the elastic modulus of the belt, that is, the elastic modulus of the material constituting the belt. Since the heat-resistant resin is a material having a small elastic modulus, a heat-resistant film is made of a material having a large elastic modulus. Preferably, it is more preferably 700 kg / mm ² or more at room temperature. In particular, when the endless belt of the present invention is used as a part of an image fixing device, since it is used at a high temperature of about 150 to 200 ° C., the elastic modulus at 200 ° C. is 150 kg.
/ Mm ² or more, more preferably,
The elastic modulus at 200 ° C. is 200 kg / mm ² or more. In addition, it is highly responsive to the conditions in which the belt is used,
It is advantageous that the strength of the heat-resistant polymer film is large in the sense that it can be used even under a large tension, and specifically, it is desirably 25 kg / mm ² or more.

The surface of the heat-resistant film is preferably subjected to a surface treatment such as a primer application, a corona discharge treatment, a plasma treatment, or a chemical-physical etching treatment in order to improve the adhesive strength with the heat-resistant resin. As the heat-resistant resin used in the present invention, those that can withstand continuous use at 200 ° C. are desirable, and specific examples include a fluorine resin, a polyimide resin, a silicone resin, an epoxy resin, a phenol resin, and an unsaturated polyester resin. I can do it. Among these, a fluororesin or a polyimide resin is particularly preferable in terms of heat resistance, durability, and the like. Examples of the fluorine resin include a tetrafluoroethylene-hexafluoropropylene copolymer resin (hereinafter abbreviated as FEP resin), an ethylene tetrafluoride-perfluoroalkoxyethylene copolymer resin (hereinafter abbreviated as PFA resin), trifluoroethylene chloride resin, There are tetrafluoroethylene-ethylene copolymer, vinylidene fluoride resin and the like, and FEP resin and PFA resin are particularly suitable for heat resistance and releasability of the endless belt.

The thickness of the heat-resistant resin layer constituting the endless belt of the present invention increases the volume fraction of the heat-resistant polymer film occupied in the endless belt, and maximizes the characteristics of thin, lightweight, high performance and high precision. For drawing out, it is preferable to use a thinner one, and it should be used in the range of 1 to 20 μm, preferably 2 to 15 μm. However, the thickness of the heat-resistant resin layer is 1
If it is less than μm, the adhesive strength of the heat-resistant film is undesirably reduced.

In the present invention, a heat-resistant resin, for example, a fluororesin or a polyimide resin may be used in the form of a film, or a fluororesin or a polyimide resin dispersed or / and dissolved in water or a solvent. A layer of a heat resistant resin may be formed and used by a method such as applying a dispersion or a solution in advance to at least one surface of the heat resistant film. As a method of forming the fluororesin layer on at least one surface of the heat-resistant film, a method of coating and sintering an aqueous dispersion of the fluororesin or extruding the molten fluororesin directly from the slit onto the heat-resistant film to laminate. And a method of thermally laminating a fluororesin film to a heat-resistant film. As a method for forming a layer such as a polyimide resin on at least one surface of the heat-resistant film, a solution such as a polyimide resin or a polyamic acid is applied and then the solvent is removed or / and the cyclization of the polyamic acid to the polyimide is performed. For example, there is a method of performing a heat treatment, a method of laminating a sheet-like polyimide resin or a polyamic acid or the like and performing a heat treatment as necessary, and in a special case, if necessary conditions are satisfied,
A commercially available product in which a heat-resistant resin is laminated on a heat-resistant film can also be used.

The heat-resistant resin may be used by forming a layer on both sides of the heat-resistant film, or a resin obtained by adding a filler such as carbon black or another inorganic material to the heat-resistant resin itself. is there. As a method of forming an endless belt using such a material, for example, a sheet in which a heat-resistant resin layer is previously formed on at least one surface of a heat-resistant film is wound on a columnar or cylindrical metal support, and heated. A method in which the interface between the heat-resistant polymer film and the heat-resistant resin is adhered by heating at a temperature equal to or higher than the melting point or the fluidization temperature of the heat-resistant resin under pressure. A method such as winding around a columnar or cylindrical metal support and heating it under pressure at a temperature equal to or higher than the melting point of the heat-resistant resin to adhere the interface between the heat-resistant polymer film and the heat-resistant resin can be used. . In addition, a method in which the material is heated by a heat source such as a heating element at the same time as the material is wound on the support, and the material is wound and adhered to be integrated.

When the material is wound on the support, a wide material is wound straight from a direction perpendicular to the support, a thin slit material is supplied to the support obliquely, and the width of the material is reduced in the longitudinal direction of the support. A method of winding up in a spiral shape or the like can be used. Here, it is important to increase the number of times the material is wound, in order to reduce the variation in thickness of the endless belt thus completed, and to improve the running stability and dimensional accuracy of the belt. The number of times of winding the material depends on the method of winding and winding the material.
Times can meet this requirement. The number of times of film lamination is not always required to be an integral multiple. For example, in the case of a method of winding a wide material straight from a direction perpendicular to the support, the winding start position and the winding end position do not need to match. The number of times of film lamination is preferably 3 to 10 times.

According to the present invention, the endless belt obtained by molding does not cause a peeled portion having a length of 1 mm or more between the layers of the heat-resistant film and the heat-resistant resin when the belt is heated to 200 ° C. for 1 minute. When the endless belt is used in an image fixing apparatus, it is very important to ensure durability and dimensional accuracy at a sufficiently high temperature. This requirement is achieved as a culmination of various technologies. First, the adhesive strength between the heat-resistant film and the heat-resistant resin at room temperature is about 0.5 kg / cm.
It is desirable to achieve the above, to achieve this, the heat-resistant film is preferably subjected to a surface treatment, for example, a corona discharge treatment, a plasma treatment, a surface roughening treatment, a chemical treatment, a silane coupling agent treatment, and the like. It is also preferable to include a specific amount of the fine inorganic compound in the heat resistant film. In addition to the adhesive strength, it is important to sufficiently expel air from the rolled-up material at the time of bonding and integration, and it is important to optimize the material supply speed and angle, heating conditions, pressing conditions, and the like. If necessary, molding under vacuum or reduced pressure may be performed. In addition, it is important to prevent dust and foreign matter from being caught during the bonding and integration of the material from the rolled up layer. Pre-processing such as molding in a so-called clean room or clean booth, cleaning the material, and removing static electricity. May also be implemented as needed.

An endless belt having a desired width can be obtained by slitting a material formed into a cylindrical shape by the above method in the circumferential direction. The slit may be selected from a method using a mechanical cutter, a method using a laser, and the like.However, a so-called laser cutter or a shear cutter is preferable because it maintains the uniformity of the end surface and does not cause damage such as notch or burn. .

At least one of the innermost surface, outermost surface, innermost surface, and outermost surface of the endless belt obtained by molding is provided on the endless belt in accordance with the characteristics of the device using the belt and the environment. For protection or to impart various functions, it may be further provided with a coating layer of fluororesin, fluororubber, silicone resin, silicone rubber, polyurethane, etc., which is one of preferred embodiments of the present invention. is there. The coating layer may contain additives for modifying carbon black, pigments, lubricating materials, abrasion-resistant materials, and the like.

The coating layer preferably has a thickness of 5 to 200 μm. If the thickness is less than 5 μm, the necessary function as the coating layer cannot often be exhibited, and if it exceeds 200 μm, the performance of the endless belt often deteriorates. A preferable application of the endless belt of the present invention is an image fixing device. In hard copy devices such as electrophotographic copying machines, printers and facsimile machines,
2. Description of the Related Art An image fixing apparatus for heating a toner image formed on a recording sheet such as printing paper and fixing the toner image on the sheet has been widely put into practical use. As the image fixing device, those having various operating principles have been proposed, but the most frequently adopted are a heating roller maintained at a predetermined temperature and a heating roller having an elastic layer provided on the surface. This is a heat roller system in which a sheet is heated and fixed while being fed. While demands for higher speed and color copying of hard copy apparatuses are increasing, it is necessary to increase the melting and fixing speed of toner in an image fixing apparatus. In the heat roller method, there is a limit in improving the fixing speed due to the relationship between heat capacity and power consumption. As a solution to this,
It has been proposed to heat-resistant resin into a belt shape and heat the sheet with a heating device through it, but it guarantees belt accuracy, running stability, and high-speed fixing to ensure clearness of printing. As described above, none of the belts (thinness), the durability of the belt, and the durability against repeated bending at high temperature have been satisfied.

On the other hand, by using the endless belt specified in the present invention, it is possible to provide an image fixing device in which all of print clarity, high-speed fixing property and durability are improved. Hereinafter, the image fixing device of the present invention will be described with embodiments. FIG. 1 is a sectional view showing an embodiment of the image fixing device of the present invention.

In FIG. 1, reference numeral 1 denotes an endless belt, which is installed so as to rotate in contact with a driving roller 4 on the left side, a driven roller 5 on the right side, and a heating body 2 installed between the rollers 4 and 5. I have. The driven roller 5 also serves as a tension control roller for the endless belt 1,
The fixing belt 1 rotates at a predetermined peripheral speed by the rotation of the driving roller 4. Reference numeral 3 denotes a pressure roller provided with an elastic layer such as silicon rubber, and is pressed against the heating body 2 with an endless belt 1 therebetween by a pressure device (not shown).

The recording sheet 6 carrying the unfixed toner image 7 sent from the image forming apparatus on the surface thereof is sent at the same speed as the endless belt 1, and is heated by the heating body 2 via the endless belt 1 to form the toner. Is melted and pressed between the endless belt 1 and the pressure roller 3 to fix the image. In the image fixing device of the present invention, a cleaning blade (not shown), a silicone oil coating device, a cooling device for a recording sheet (sheet on which an image is fixed), a recording sheet peeling device, and the like are appropriately provided around the endless belt 1. Can be placed.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) A PPTA film having a thickness of 12 μm and a width of 250 mm (about 0.1 μm silica particles of 0.4 μm).
Weight%, elastic modulus at room temperature 1400 kg / mm ² , 2
A modulus of elasticity of 1100 kg / mm ^{2 at} 00 ° C., which has been subjected to corona discharge machining) and a PF having a thickness of 6 μm and a width of 250 mm.
A resin film, 500m outside diameter in a clean booth
The PFA resin film was placed in an iron mold having a thickness of 7 mm, a thickness of 7 mm, and a width of 600 mm so as to be in contact with the mold, and the two films were wound six times.

Overlap portion (the portion to be the 7th round)
Was cut to a length of 10 mm, and both ends were firmly stuck to a mold with heat-resistant adhesive tape. Next, a heat-resistant release agent was applied to a thickness of 25 μm and a width of 10 mm.
Kapton (aromatic polyimide) film tape is set in a feeder equipped with a traverse mechanism, and the mold is rotated while traversing so that the lateral movement amount (traverse amount) per mold rotation is 2 mm. It was taped with film tape and tightened. Cut the wound tape while taking care not to loosen it, fix the end to the mold with heat-resistant adhesive tape,
It was placed in a vacuum heating furnace controlled at 0 ° C. and heated for 30 minutes. After the mold was removed from the heating furnace and cooled, the Kapton film tape was removed, and then the laminate was removed from the mold.

In this way, the laminated structure is 6 μm from the inside.
The mPFA resin and the 12 μm aramid film are alternately laminated in six layers each and integrated into a total thickness of about 110 μm.
m, a width of 250 mm, a circumference of 1570 mm, and an endless laminate having a film volume fraction of 67%. This endless laminate is set in a cutting machine, and the width is set to 20 with a shear cutter.
It was slit to 0 mm. This endless laminate is
After leaving for 1 minute in an oven heated to 0 ° C., it was taken out, but no peeling was observed.

The inner and outer layers and end faces of the obtained aramid film-laminated endless belt were coated with a silicone rubber of about 80 μm.
After coating with an m-thick endless belt having a total thickness of about 270 μm, it was incorporated into an image fixing device schematically shown in FIG. The heating of the image fixing apparatus, while heating the endless belt at about 200 ° C., is rotated ¹⁰⁶ times, and observed the degree of fatigue of the endless belt. After the operation in the image fixing device, the belt was not different from that before the operation, and phenomena such as damage and peeling were not observed at all.

(Example 2) The thickness of 12 μm used in Example 1
m, PFA dispersion (manufactured by DuPont Fluorochemicals Co., Ltd.) on both sides of a PPTA film 250 mm wide
Was coated so that the thickness of the PFA resin was 2 μm on both sides, and then heated and baked to produce a laminate sheet coated on both sides with the PFA resin in a clean booth. This laminated sheet was supplied to an iron mold having an outer diameter of 25 mm, a thickness of 5 mm, and a width of 600 mm, and was rolled up five times while pressing the mold with a roller heated to 320 ° C. Approximately 5mm in the overlap area (the part to be the 6th round)
Then, the sheet was cut so that the end portion was firmly attached to a mold with a heat-resistant adhesive tape.

Next, a thickness 25 coated with a heat-resistant release material in advance
A 10 mm wide tape of a Kapton film of μm is set in a feeding machine equipped with a traverse mechanism, and the mold is rotated while traversing so that the traverse amount per mold rotation is 2 mm. Taping and tightening were performed so that the coated surface was on the laminate sheet side. The wound tape was cut while being careful not to be loosened, and the end was stuck to a mold with a heat-resistant adhesive tape and fixed, and then the mold was placed in a vacuum heating furnace at 330 ° C. and heated for 25 minutes. After the mold was taken out of the heating furnace and cooled, the Kapton tape was removed, the laminate was extracted from the mold, and both ends were trimmed with a shear cutter to form a laminate structure of 2 μm of PFA resin and PPTA film 12 from the inside.
μm, PFA resin 4 μm, PPTA film 12 μm,
PFA resin 4μm, PPTA film 12μm, PFA
Resin 4μm, PPTA film 12μm, PFA resin 4
A film belt having a thickness of 80 μm, a width of 230.5 mm, and a circumference of 75.8 mm was obtained by alternately laminating a PPTA film layer and a fluororesin layer, each having a thickness of μm, a PPTA film of 12 μm, and a PFA resin of 2 μm. The volume fraction of the PPTA film in the belt was 75%. The film belt was allowed to stand in a 200 ° C. oven for 1 minute and then taken out, but no delamination was observed.

The obtained film belt was used as a commercially available laser beam printer (manufactured by Canon Inc., LBP-L) using a polyimide seamless film belt as the image fixing device.
430 type), and a halftone plain (so-called solid) print signal was input from a personal computer from a personal computer to perform test printing. The test print is a pattern in which 100 sheets are continuously printed, then printing is stopped for 10 minutes, and 100 sheets are continuously printed.
000 prints were performed. During this time, the belt was able to run smoothly without any wrinkles, peeling or damage, and no print spots were detected.

Example 3 A stretched polyimide film having a thickness of 20 μm and a silica particle content of 1.2% by weight (room temperature, 2
The elastic modulus at 00 ° C is 700 kg / mm ² , 600 respectively.
kg / mm ² , a sandblasted surface-roughened surface) was used to obtain a laminated sheet having both surfaces coated with a 2 μm PFA resin. Then, exactly as in Example 2,
I made a film endless belt.

As described above, when the laminated structure is formed from the inside, the PF
A resin 2 μm, polyimide film 20 μm, PFA resin 4 μm, polyimide film 20 μm, PFA resin 4
μm, polyimide film 20μm, PFA resin 4μ
m, polyimide film 20 μm, PFA resin 4 μm,
A film belt having a thickness of 120 μm, a width of 230.5 mm, and a circumference of 75.8 mm was obtained by alternately laminating and integrating a polyimide film layer and a fluororesin layer, each having a polyimide film of 20 μm and a PFA resin of 2 μm. The volume fraction of the polyimide film in the belt was 83%. The film belt was taken out after standing in an oven at 200 ° C. for 1 minute, but no delamination between layers was observed.

The obtained film endless belt was coated on the outer layer of the endless belt with silicon rubber to a thickness of about 30 μm to form an endless belt having a total thickness of about 150 μm, and then incorporated in the image fixing device of Example 2. It is. The same test as in Example 2 was carried out, and it was confirmed that there was no wrinkle, peeling, damage, or the like of the belt at all, and no printing spots.

(Example 4) In a clean booth, a thickness of 6
μm PPTA film (containing 0.2% by weight of silica particles, elastic modulus at room temperature and 200 ° C. is 1400 kg /
mm ² , 1100 kg / mm ² , corona discharge treated)
A polyimide varnish (SOXR, manufactured by Nippon Advanced Paper Industry Co., Ltd.) was applied to both sides of the resin to a thickness of about 6 μm.
Heat to 20 ℃ to remove the solvent in the polyimide varnish,
A polyimide resin layer of about 2 μm was formed on both sides of the PPTA film.

From this laminated sheet, a film endless belt was produced in the same manner as in Example 2. However, the number of times of winding is 7 times, and the endless belt before silicon rubber coating is
Total thickness of about 60μm, PPTA film volume fraction 75%
After leaving it still in an oven at 200 ° C. for 1 minute, there is no peeling even when it is taken out.
m, the total thickness of the endless belt after coating is about 140 μm
Met. When the test printing was carried out in the same manner as in Example 2 by assembling into the image fixing device, there was no trouble or damage of the endless belt, and there was no printing unevenness.

Example 5 A 25 μm-thick polyimide stretched film containing 1% by weight of silica particles (room temperature
0 ° C elastic modulus of 700 kg / mm ² and 600 kg respectively
/ Mm ² , corona discharge treated) and a polyimide resin-based thermoplastic heat-resistant adhesive (Ubitite manufactured by Ube Industries, Ltd.) to prepare a laminated sheet. That is, in a clean booth, a polyimide-based heat-resistant adhesive sheet having a release film with a thickness of about 20 μm was peeled off on one side of the polyimide stretched film at 180 ° C. while peeling off the release sheet on one side.
Lamination was performed by applying a surface pressure of 0 kg / cm ² .

Next, while peeling off the remaining release sheet,
In the same manner as in Example 1, a laminated endless belt was manufactured.
However, assuming that the number of times of winding is three times, the thickness is about 135 μm,
The volume fraction of the polyimide film in the belt was 56%. The film belt was allowed to stand in an oven at 200 ° C. for 1 minute to conduct a peeling test.
As in Example 3, only the outer layer of the endless belt was coated with silicon rubber to a thickness of about 20 μm, and the total thickness was about 15 μm.
Test printing was performed using an image fixing device in the same manner as in Example 2 as a 5 μm endless bell. It was confirmed that there was no trouble or damage on the endless belt, and there was no printing unevenness.

Comparative Example 1 The procedure of Example 1 was repeated, except that the PPTA film not subjected to the corona discharge treatment was used, and the heat treatment of the laminated molded product was carried out under normal pressure.
Was repeated. Before being covered with silicon rubber, it was left in an oven at 200 ° C. for 1 minute and then taken out.
Delamination with a length of about 10 to 10 mm was observed. Another endless belt (20
(Not subjected to an oven test at 0 ° C.) was coated with silicone rubber in the same manner as in Example 1, and an operation with an image fixing device was performed. When the endless belt was observed after the operation, about half of the laminated portion was peeled off, and the end portion was damaged.

A sheet in which the PPTA film and the PFA resin film are “wrapped” only once is specially made.
A 12 μm electrolytic copper foil was placed on the PFA side, and a surface pressure of 10 kg / cm ² and a temperature of 130 ° C. for 30 minutes (temperature rising rate of 3 ° C. /
Min), and then subjected to hot press molding at a surface pressure of 20 kg / cm ² and a temperature of 200 ° C. for 60 minutes (heating rate of 3 ° C./min) to form a copper-clad laminate. The adhesive strength was 0.2 to 0.4 kg / cm. Incidentally, when the same special sheet / copper-laminated laminate was made in Example 1 and the adhesive strength was measured, it was 1.2 kg / cm.

Comparative Example 2 In Example 1, PPTA was used.
Example 1 was repeated except that the film thickness was 6 μm. The film volume fraction in the laminated endless belt is 50
%, And the end of the belt after operation with the image fixing device was wrinkled due to insufficient rigidity. (Comparative Example 3) Example 4 was repeated, except that the thickness of the PPTA film was changed to 50 µm. Streaks were observed in the prints which were presumed to be affected by film thickness.

[0056]

The endless belt of the present invention has heat resistance, excellent dimensional accuracy even in a high temperature environment, and excellent flex fatigue life, so that it can be operated for a long time with high reliability even in a high temperature environment. Since it is possible and has good heat conductivity, it can be used with little energy and is suitable as an image fixing belt used in a copying machine or a printer. Further, the image fixing device is characterized by print clarity, high-speed fixability, and durability, and is additionally provided with features such as compactness, power saving, and high reliability.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image fixing device using an endless belt of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 endless belt 2 heating element 3 pressure roller 4 drive roller 5 driven roller 6 recording sheet 7 toner image

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2H033 AA23 BA11 BE03 4F100 AA20 AK01A AK01B AK17B AK17C AK17D AK17E AK47A AK49A AK49B AK51C AK51D JAK BAE BAA BAE BAA BAE BAA JA20B JA20C JA20D JA20E JJ01 JJ03A JJ03B JK04 JK06 JL04 YY00 YY00A YY00B YY00C YY00D YY00E 4J002 CL061 CM021 CM031 CM041 CN061 DA036 DA066 DE106 DE136 DE146 DE236 DG046 DG000 DJ006 DJ016 DJ016

Claims (10)

[Claims] 1. An endless belt having a laminated structure in which heat-resistant films made of a polymer material that does not melt and decompose at a temperature lower than 350 ° C. are bonded to each other by a heat-resistant resin, and have a film thickness of 2 to 30 μm. The resin thickness is 1 to 20 μm, the belt thickness is 50 to 300 μm, the volume fraction of the film in the belt is 55 to 95%, the number of times of film lamination is at least two times, and the belt is heated to 200 ° C. An endless belt characterized in that a delamination portion having a length of 1 mm or more does not occur even after holding for 1 minute. 2. The method according to claim 1, wherein at least one of the innermost surface, outermost surface, innermost surface, and outermost surface of the laminated endless belt is selected from fluororesin, silicone resin, fluororubber, silicone rubber, and polyurethane. The endless belt according to claim 1, further comprising a coating layer made of any one of the above materials. 3. The endless belt according to claim 1, wherein the heat-resistant film is a film made of an aromatic polyamide or an aromatic polyimide. 4. The endless belt according to claim 1, wherein the heat-resistant resin is a fluororesin or a polyimide resin. 5. The endless belt according to claim 1, wherein the coating layer has a thickness of 5 to 200 μm. 6. An apparatus for heating and fixing a toner image carried on a recording sheet, comprising a heating head and an endless belt moving with the recording sheet, wherein the endless belt melts and decomposes at a temperature lower than 350 ° C. A heat-resistant film made of a non-polymeric material that is bonded and laminated to each other with a heat-resistant resin.
~ 30μm, resin thickness 1 ~ 20μm, belt thickness 50 ~
300 μm, and the volume fraction of the film in the belt is 5
5 to 95%, and the number of film laminations is at least 2
An image fixing device wherein the belt is kept at 200 ° C. for 1 minute, and a delamination portion having a length of 1 mm or more is not generated. 7. At least one of the innermost surface, outermost surface, innermost surface, and outermost surface of the laminated endless belt is selected from fluororesin, silicone resin, fluororubber, silicone rubber, and polyurethane. 7. The image fixing device according to claim 6, wherein an endless belt is provided with a coating layer made of any one of the above materials. 8. The image fixing device according to claim 6, wherein the heat-resistant film is a film made of aromatic polyamide or aromatic polyimide. 9. The image fixing device according to claim 6, wherein the heat-resistant resin is a fluororesin or a polyimide resin. 10. An endless belt according to claim 6, wherein the coating layer has a thickness of 5 to 200 μm.
10. The image fixing device according to any one of claims 9 to 9.