JP2002188620A - Tubular body - Google Patents

Abstract

(57) [Problem] To provide a fixing belt having excellent durability. SOLUTION: A first primer layer 8, a thermosetting synthetic resin layer 9 and a second primer layer 10 are provided in this order on an outer peripheral surface of an innermost layer 5 made of a porous polytetrafluoroethylene resin (PTFE). Then, the outermost layer 7 made of porous PTFE is covered and thermally contracted. The first primer layer 8 penetrates into the many through holes 11 in the innermost layer 5, and the second primer layer 10 penetrates into the many through holes 12 in the outermost layer 7, so that the adhesive strength is improved by the anchor effect. The outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 may be defluoridated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical body, and more particularly to a cylindrical body suitably used for a fixing belt provided in a fixing device of an electrophotographic image forming apparatus such as a copying machine and a laser beam printer. .

[0002]

2. Description of the Related Art The prior art of an image forming apparatus provided with a fixing device using a fixing belt is disclosed, for example, in JP-A-11-133.
776. The recording paper on which the toner image is transferred and carried on the surface thereof is conveyed by being sandwiched between a heated fixing roll and a fixing belt pressed by a pressing piece toward the fixing roll in the fixing device, and the toner is conveyed. Is heated and melted, adheres to the surface of the recording paper, and is fixed. The fixing belt is endless, and is pressed against the fixing roll by a pressing piece disposed inside the fixing belt. The prior art discloses, as a fixing belt, a configuration in which a base layer of polyimide, polyamide, or polyamideimide is coated on both surfaces with a layer of a fluororesin such as a perfluoroalkylvinylether (abbreviated as PFA) copolymer resin.

[0003] In such a fixing device, the toner does not adhere to the outer peripheral surface of the fixing belt, so that the releasability can be improved, thereby preventing the outer peripheral surface of the fixing belt from being stained. It is possible to prevent the recording paper from being stained by the toner remaining on the outer peripheral surface. Further, as described above, the fixing belt is pressed toward the fixing roll by the pressing piece, and the coefficient of friction between the inner peripheral surface of the fixing belt and the pressing piece is small. When the recording paper is sandwiched between the outer peripheral surface of the fixing roll and the outer peripheral surface of the fixing roll, the recording paper can smoothly follow the outer peripheral surface of the fixing roll at the same speed without causing a slip, and an accurate fixing operation can be performed.

[0004] In this prior art, the adhesive strength between the fluororesin layer and the base layer is poor, and there is a possibility that the fluororesin layer is peeled and damaged. Particularly, in a relatively high temperature atmosphere for thermal fixing, there is a high possibility that the fixing belt is damaged. That is, in the prior art, the durability of the fixing belt is inferior.

[0005]

An object of the present invention is to provide a cylindrical body having excellent durability.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a tubular body having an innermost layer made of a fluororesin and an adhesive layer formed on the outer peripheral surface of the innermost layer with improved adhesive strength and having at least a layer made of a thermosetting synthetic resin. A cylindrical body characterized by including outermost layers 6, 17, and fluororesin outermost layers 7, 17 formed on the outer peripheral surface of the cylindrical main body with improved adhesive strength.

According to the present invention, the innermost layer 5 made of fluororesin and the outermost layer 7, 1 made of fluororesin are provided on both surfaces of the cylindrical main bodies 6, 21.
7, the adhesive strength between the tubular main body and the innermost layer is improved, and the adhesive strength between the cylindrical main body and the outermost layer is improved. Therefore, in the fixing device of an electrophotographic image forming apparatus, for example, in a fixing device of an electrophotographic image forming apparatus, the innermost layer and the cylindrical main body can be formed even under an atmosphere of a relatively high temperature at which toner softens or melts. There is no peeling, and the tubular body and the outermost layer do not peel, so that the durability is improved.

The cylindrical bodies 6, 21 have at least thermosetting synthetic resin layers 9, 22 and have high mechanical strength such as high tensile strength even in a high-temperature atmosphere such as heat fixing. This high temperature atmosphere is, for example, 150
To 200 ° C. In addition to the layer made of thermosetting synthetic resin, the cylindrical body is further additionally provided with other layers 8,
10, 23 may be laminated.

Since the innermost layer 5 and the outermost layers 7, 17 are made of a fluororesin, they are not stained by, for example, toner, have good releasability, and have a low friction coefficient, so that they can be smoothly slid. Movement is realized.

In order to improve the adhesive strength between the innermost layer 5 and the cylindrical main bodies 6, 21, for example, the innermost layer 5 is made porous,
The material constituting the cylindrical main body may penetrate into the large number of through holes in the innermost layer, and achieve strong adhesion by its anchor (anchor) effect. Alternatively, the outer surface of the innermost layer 5 bonded to the cylindrical bodies 6 and 21 is subjected to defluorination treatment so that the outer peripheral surface of the innermost layer and the cylindrical body are easily conformed to each other, the affinity for the interface is improved, and a strong Adhesion may be achieved. Such a structure for improving the adhesive strength between the innermost layer and the cylindrical main body is the same as for the adhesion between the cylindrical main bodies 6, 21 and the outermost layers 7, 17. The configuration for improving the adhesive strength may be achieved by another configuration.

Further, according to the present invention, the cylindrical main body 6 comprises a first primer layer 8 formed on the outer peripheral surface of the innermost layer, and a thermosetting synthetic resin layer formed on the outer peripheral surface of the first primer layer. 9 and
A second primer layer formed on the outer peripheral surface of the thermosetting synthetic resin layer.

According to the present invention, as shown in FIG.
On both surfaces of the thermosetting synthetic resin layer 9, the first
And a configuration sandwiched by the second primer layers 8 and 10. These primer layers 8 and 10 have a higher softening point or melting point than the fluororesin and the thermosetting synthetic resin, and the adhesive strength between the primer layer and the thermosetting synthetic resin layer is improved. Of course, the adhesive strength between the innermost layer 5 made of fluororesin and the first primer layer 8 is high, and the adhesive strength between the second primer layer 10 and the outermost layer 7 made of fluororesin can be increased. Further, by forming the first and second primer layers 8 and 10 from a resilient synthetic resin material such as rubber, for example, the recording paper on which the toner image is adhered to a fixing roll in a fixing device. Therefore, it can be held between the fixing roll and a suitable elastic force.

The primer layers 8 and 10 have good wettability with the innermost layer 5 made of fluorocarbon resin and the outermost layer 7 made of fluorocarbon resin, and have good wettability with the layer 9 made of thermosetting synthetic resin. The material of such primer layers 8, 10 may be rubber or the like. The contact angle of the thermosetting synthetic resin layer when the material of the liquid thermosetting synthetic resin layer containing a solvent is dropped directly on the surface of the innermost layer 5 or the outermost layer 7 is θ1, and the innermost layer 5 or When the material of the liquid primer layers 8, 10 containing a solvent is dropped on the surface of the outermost layer 7, the contact angle of the primer layers is defined as θ2, and the primer layers 8, 1
When the contact angle of the thermosetting synthetic resin layer 9 when the material of the liquid thermosetting synthetic resin layer 9 containing a solvent is dropped on the surface of 0 is θ3, θ1> θ2 and θ1> θ3.
The material of the primer layers 8 and 10 is selected so that the following holds.

Further, the present invention is characterized in that the innermost layer 5 is porous, and the first primer layer 8 is formed in a state in which it penetrates the respective through holes 11 of the innermost layer.

Further, the present invention is characterized in that the outermost layer 7 is porous, and the second primer layer 10 is formed in a state of penetrating each of the through holes 12 of the outermost layer.

According to the present invention, the innermost layer 5 and the outermost layer 7
At least one of the first and second primer layers 8 and 10 is porous and has a large number of through holes 11 and 12.
Are formed in a state of invading each through hole. Therefore, the anchor effect is exhibited by the penetration of the primer layer into the through hole, and the adhesive strength is improved.

The term "porous" refers to a structure in which a large number of fine through holes penetrating in the thickness direction may be formed, or a large number of minute concave portions not penetrating in the thickness direction. Including configuration.

Further, according to the present invention, the cylindrical main body 21 includes the innermost layer 5.
A thermosetting synthetic resin layer 22 formed on the outer peripheral surface of
And a primer layer formed on the outer peripheral surface of the thermosetting synthetic resin layer.

Further, according to the present invention, the innermost layer 5 is porous, and the thermosetting synthetic resin layer 22 is formed as the innermost layer of each through-hole 11.
It is characterized in that it is formed in a state where it has penetrated into.

Further, the present invention is characterized in that the outermost layer 7 is porous, and the primer layer 23 is formed in a state in which it penetrates each through hole 12 of the outermost layer.

According to the present invention, as shown in FIG. 5, the cylindrical main body 21 is formed by laminating a thermosetting synthetic resin layer 22 and a primer layer 23 in order from inside to outside. Simplified. By making the innermost layer 5 porous,
The thermosetting synthetic resin layer 22 penetrates each through hole of the innermost layer,
The adhesive strength is improved by the anchor effect. Further, by making the outermost layer 7 porous, the primer layer 23 penetrates into the through-holes of the outermost layer 7, and the anchor effect is exerted to improve the adhesive strength. By using a fluorine resin as the thermosetting synthetic resin 22, the adhesive strength to the innermost layer 5 made of the fluorine resin is increased.

Each of the through holes 11 and 12 communicates with the inner peripheral surface and the outer peripheral surface of the innermost layer 5 and / or the outermost layer 7.
When the resin is applied on the outer peripheral surface of the innermost layer 5 to form one or a plurality of layers in the cylindrical main bodies 6, 21, air is trapped between the cylindrical main body and the resin forming the applied layers. Thus, a layer having a uniform surface can be formed without bubbles being formed and no irregularities being formed by the bubbles. In addition, since the resin forming each layer easily pushes out the air in the through-hole and enters the resin, the resin penetrates into the through-hole by the action of surface tension or the like so as not to form unevenness after the brush is peeled off. A surface layer can be formed.

Further, the present invention is characterized in that at least one of the outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 is subjected to a defluorination treatment.

According to the present invention, at least one of the innermost layer 5 and the outermost layers 7 and 17 is porous as described above, and is further subjected to defluorination treatment so that the cylindrical main bodies 6 and 21 are separated from each other. Is further improved. That is, the anchor effect is exhibited when at least one of the innermost layer and the outermost layer is porous. In addition, since at least one of the outer peripheral surface of the innermost layer and the inner peripheral surface of the outermost layer is subjected to the defluorination treatment as described above, it becomes easy to adapt to the cylindrical main body, and repelling when the cylindrical main body is applied. , Adhesion is facilitated, interface affinity is improved, and bonding strength is further increased.

Further, the present invention is characterized in that at least one of the outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 is smooth and defluoridated.

According to the present invention, the innermost layer 5 and the outermost layers 7, 1
At least one of 7 is smooth, that is, not porous, but is defluorinated. Even with such a configuration, it is possible to improve the compatibility with the cylindrical main body, improve the interface affinity, and provide strong adhesion. Can be achieved.

In the present invention, the fluororesin of the innermost layer 5 and the outermost layer 7 is made of a polytetrafluoroethylene resin, has an outer diameter of 10 mm or more and 200 mm or less, and has a seamless cylindrical shape having a thickness of 50 μm or more and 200 μm or less. The porous properties are as follows: the maximum pore size is 0.2 μm or less;
The porosity is 25% or more and 50% or less, and the air permeability is 500
Seconds / 100 cc or more and 30,000 seconds / 100 cc or less, and the surface roughness is 0.5 μm as the center line average roughness Ra.
m or less. The outer diameter is 100m
m or less.

According to the present invention, the tubular body is a seamless tubular body, and regarding the properties of the polytetrafluoroethylene resin, the center line average roughness Ra of the inner and outer peripheral surfaces of the polytetrafluoroethylene resin is 0. 0.5 μm, the inner and outer peripheral surfaces thereof are uniform, and the outer diameter of the cylindrical body is 10 mm or more and 200 mm or less, so that a cylindrical body having a uniform thickness can be easily formed. Can be. Also, if the thickness of the polytetrafluoroethylene resin is 50
Since it is not less than μm and not more than 200 μm, it is possible to obtain a cylindrical body having sufficient durability and capable of easily partially changing the curvature.

The porous properties of the polytetrafluoroethylene resin are such that the air permeability is 500 seconds / 100 cc or more and 3000 or more.
0 seconds / 100 cc or less, so that the cylindrical main bodies 6, 21,
In particular, the first primer layer 8 and / or the second primer layer 1
0 invades moderately and the cylindrical body 6, 2 with a sufficiently high adhesive force.
1 can be adhered. The maximum pore size is 0.2μ
m and the porosity is 25% or more and 50% or less, so that the above-described air permeability can be achieved.

Further, the present invention is characterized in that the innermost layer and the outermost layer are made of a polytetrafluoroethylene resin or a perfluoroalkyl vinyl ether resin.

Further, the present invention is characterized in that the thermosetting synthetic resin is a fluororesin, an imide resin or a polyethersulfone resin.

Further, the present invention is characterized in that the primer is made of fluorine rubber or silicon rubber.

According to the present invention, by using the above-mentioned fluororesin, it is possible to realize the releasability and the low coefficient of friction, to improve the heat resistance, to increase the tensile strength and to improve the durability. Performance can be improved. The primer is made of rubber as described above, so that not only the adhesion strength can be improved, but also the resilience, for example, the recording paper is pressed against the fixing roll by a fixing belt with an appropriate pressure by a fixing belt in a fixing device, and an accurate pressure is applied. Fixing can be performed.

Further, an oil, for example, a silicone oil may be retained and used. In this case, since the outermost layer 7 is porous, it can be impregnated with the silicon oil and retained. As compared with the case of applying to the outer peripheral surface, the retention of silicone oil is improved. In this way, it can be used in a state where it is impregnated with silicon oil and held securely. Depending on the fixing speed, sufficient release properties of the toner without offset can be obtained only by the characteristics of the fluororesin. Therefore, the silicone oil is not necessarily used but may be appropriately designed.

Further, the present invention is characterized in that the ratio (t / D1) between the thickness t and the outer diameter D1 is 1/50 to 1/1000.

Further, the present invention is characterized in that the ratio (t / D1) between the thickness t and the outer diameter D1 is 1/100 to 1/500.

According to the present invention, the aforementioned ratio t / D1 is
1/50 to 1/1000, preferably 1/100 to 1 /
500, thereby realizing a cylindrical body having improved durability in applications such as a fixing belt.

Further, the present invention is characterized in that the cylindrical bodies 6, 21 include a layer having conductivity.

The present invention also provides a thermosetting synthetic resin layer 9,
The 22 or the primer layers 8, 10, 23 are characterized by having conductivity.

Further, the present invention is characterized in that the innermost layer 5 has conductivity. Further, the present invention is characterized in that the conductivity is a volume resistance value of 10 ⁴ to 10 ¹⁰ Ω · cm.

According to the present invention, when the cylindrical body of the present invention is used as a fixing belt of a fixing device in an electrostatic image forming apparatus, at least a part of layers 8 to
Reference numerals 10, 22, and 23 have conductivity, and furthermore, the innermost layer 5 has conductivity, so that electric charges charged in the cylindrical body can be eliminated or reduced. Therefore, the toner on the recording paper does not scatter due to the electric charge charged on the cylindrical body, and thus the toner image is not disturbed and the fixed image quality does not deteriorate. Further, by selecting the volume resistance value within the above-mentioned range, a sufficient fixing image quality can be obtained in practice, and the production is easy.

Further, according to the present invention, the tensile yield load in the circumferential direction is
It is characterized by not less than 2.5 kg weight per 1 cm of axial width.

Further, according to the present invention, the tensile yield stress in the circumferential direction is
It is characterized by being 150 kgf / cm ² or more.

Further, according to the present invention, the tensile modulus of elasticity in the circumferential direction is
7000 kgf / cm ² or more.

According to the present invention, even if a tensile load is applied in the circumferential direction, if the tensile yield load in the circumferential direction is less than 2.5 kg weight per 1 cm in the axial direction, the cylindrical body maintains its elasticity. ,
Performance can be maintained. For example, a load of 2.5 kg or more per 1 cm of width in the axial direction is not applied to a belt provided in a copying machine or the like in the circumferential direction. As a belt, for example, a fixing belt, it can be suitably used with high durability. This belt is used for power transmission or for transportation, and for other uses.

According to the present invention, even if a tensile load is applied in the circumferential direction, the tensile yield stress in the circumferential direction is 150 kgf / cm ^2.
If the load is less than the above, the elasticity of the cylindrical body can be maintained and the performance can be maintained. For example, a belt provided in a device such as a copying machine has a weight of 150 kg /
A tensile load that generates a tensile stress of not less than ² cm ² does not act, and therefore, the cylindrical body can be suitably used with high durability as a belt for equipment such as the copying machine, for example, a fixing belt. .

According to the present invention, even when a tensile load is applied in the circumferential direction, the tensile elastic modulus in the circumferential direction is 7000 kgf / cm.
Since it is ² or more, its circumferential dimension does not greatly change. For example, a belt provided in a device such as a copying machine, with respect to the circumferential direction, there is no tensile load that greatly changes the circumferential dimension of the belt of the tensile elastic modulus of the numerical value described above, therefore, the tubular body, It can be used in a suitable state with little elongation as a belt for equipment such as the copying machine, for example, a fixing belt.

Further, according to the present invention, the cylindrical main bodies 6, 21 are formed by applying a solution in the form of a solution on the outer peripheral surface of the innermost layer 5 made of polytetrafluoroethylene resin.
Primer layers 10 and 23 are formed on the outer peripheral surfaces of thermosetting synthetic resin layers 9 and 22, and the outermost porous layer 7 made of polytetrafluoroethylene resin is combined with the primer layer 1.
The primer layer 1 is placed on the outer peripheral surface of
A method for producing a cylindrical body, characterized in that the outermost layer 7 is thermally shrunk by heating to a temperature equal to or higher than the melting point of 0,23.

In the present invention, the cylindrical main bodies 6, 21 are formed by applying a solution in the form of a solution on the outer peripheral surface of the innermost layer 5 made of polytetrafluoroethylene resin.
Primer layers 10 and 23 are formed on the outer peripheral surfaces of thermosetting synthetic resin layers 9 and 22, and outermost layers 7 and 8 of polytetrafluoroethylene resin whose inner peripheral surfaces are defluorinated.
17. A method for producing a cylindrical body, wherein the outermost layer is thermally shrunk by heating above the melting point of the primer layers 10, 23 while covering the outer peripheral surfaces of the primer layers 10, 23. is there.

According to the present invention, at least the thermosetting synthetic resin layers 9 and 22 are formed on the outer peripheral surface of the innermost layer 5 made of the polytetrafluoroethylene resin shown in FIGS. 1, 4, 5 and 7. And the primer layers 8, 10, and 23 are sequentially applied in a liquid state to form a cylindrical body.
1, the outermost layer 7, 1 made of polytetrafluoroethylene resin
In the state where the outermost layers 7 and 17 are covered, the outermost layers 7 and 17 are thermally contracted by heating to a temperature higher than the melting point of the primer layers 8, 10 and 23. The outermost layers 7, 17 are porous, so that the primer layers 10, 23 penetrate into a large number of holes in a molten state, and an anchor effect is exhibited. The inner peripheral surfaces of the outermost layers 7 and 17 may be subjected to a defluorination treatment. At this time, the outermost layers 7 and 17 may be porous, but may have a nonporous smooth structure. , 23 in a molten state are adhered to the inner peripheral surfaces of the outermost layers 7, 17 with high adhesive strength.

In another embodiment of the present invention, as shown in FIGS. 1 and 4, the first primer layer 8 is formed on the outer peripheral surface of the innermost layer 5.
Is formed by being applied in a solution state, and thereafter, the thermosetting synthetic resin layer 9 is applied in a solution state as described above,
Further, the second primer layer 10 may be formed to form the cylindrical main body 6.

Further, in the present invention, the innermost layer 5 is formed by forming a raw material cylinder by paste extrusion molding, and expanding the raw material cylinder at least in the radial direction at an expansion working temperature not lower than the softening point and lower than the melting point. After that, the expanded raw material cylinder, at the expansion processing temperature or higher, at a temperature lower than the temperature at which the decomposition of the polytetrafluoroethylene resin occurs remarkably, remain porous,
It is characterized by being formed by heat setting.

According to the present invention, the innermost layer 5 and / or the outermost layers 7, 17 are formed by expanding the raw material cylinder at least in the radial direction at an expansion working temperature not lower than the softening point but lower than the melting point, and heat setting. Therefore, a cylinder in which the through holes 11 and 12 are formed uniformly can be easily manufactured.

According to the present invention, there is provided a fixing belt for fixing a toner image carried on a recording medium by applying heat and pressure, wherein the fixing belt is the above-mentioned tubular body.

According to the present invention, the innermost layer 5 and / or the outermost layers 7 and 17 of the fixing belt are bonded to the cylindrical main bodies 6 and 21 with improved adhesive strength. Therefore, although the innermost layer 5 and the outermost layers 7 and 17 are made of fluororesin and are hardly compatible with other types of synthetic resins, the adhesive strength with the cylindrical main bodies 6 and 21 is improved, and the durability is improved. be able to. Further, since the innermost layer 5 is made of a fluororesin as described above, in the configuration in which the fixing belt 3 is resiliently pressed by the pressing piece 29 against the fixing roll 28 in FIG. The coefficient of friction with the piece 29 is reduced, and the recording paper 25 having the toner image 26 can be pinched and conveyed by the fixing belt 3 smoothly driven by the fixing roll 28. Further, since the outermost layers 7 and 17 are also made of a fluororesin as described above, they are excellent in toner releasability and are not stained. There is no danger of contamination. The present invention also relates to a fixing device provided with such a fixing belt, and an electrophotographic image forming apparatus provided with such a fixing device.

[0056]

FIG. 1 is an enlarged sectional view of a part of a tubular body 1 according to one embodiment of the present invention. This tubular body 1
It is used as a fixing belt 3 of a fixing device 2 (see FIG. 8 described later) provided in an electrophotographic image forming apparatus. The cylindrical body 1 is basically made of an innermost layer 5 made of fluororesin, a cylindrical body 6 formed on the outer peripheral surface of the innermost layer 5, and a fluororesin formed on the outer peripheral surface of the cylindrical body 6. And an outermost layer 7. The tubular body 1 is a straight cylinder in a natural state where no external force acts.

The cylindrical main body 6 includes a first primer layer 8 formed on the outer peripheral surface of the innermost layer 5, a thermosetting synthetic resin layer 9 formed on the outer peripheral surface of the first primer layer 8, A second primer layer formed on the outer peripheral surface of the thermosetting synthetic resin layer. The innermost layer 5 and the outermost layer 7 are made of, for example, polytetrafluoroethylene resin (abbreviated as PTFE) as an example of a fluororesin,
12 is porous. These through holes 11 and 12
Penetrates in the thickness direction (vertical direction in FIG. 1). First
The primer layer 8 is formed in a state penetrating into each through hole 11 of the innermost layer 5, and the second primer layer 10 is formed in a state penetrating into each through hole 12 of the outermost layer 7, thereby achieving the anchor effect. Thus, the adhesive strength is improved.

The porous property of the innermost layer 5 is such that the maximum pore size is 0.2
μm or less, the porosity is 25% or more and 50% or less, and the air permeability is 500 seconds / 100 cc or more and 30000 seconds /
100 cc or less. The air permeability is also called air permeability or Gurley number, and is based on Japanese Industrial Standard JIS P-8117-1.
980. The surface roughness of the innermost layer 5, specifically, the surface roughness of the inner peripheral surface and the outer peripheral surface is 0.5 μm or less as a center line average roughness Ra.

It is preferable that the through holes 11 are uniformly dispersed without bias so that the innermost layer 5 is macroscopically homogeneous. Further, it is preferable that each through hole 11 has a shape in which the inner surface shape is not uniform but changes in the thickness direction of the innermost layer 5.

The PTFE resin on which the innermost layer 5 is formed may be a tetrafluoroethylene homopolymer resin, and may be 2% by weight or less (preferably 0.01% by weight or more and 1% by weight or less).
(% By weight or less) so-called modified polytetrafluoroethylene obtained by copolymerizing a copolymerizable monomer. The copolymerized monomer may be perfluoroalkyl vinyl ether, chlorotrifluoroethylene, hexafluoropropylene, or the like. The outermost layer 7
It is configured similarly to the innermost layer 5.

The through holes 11 of the innermost layer 5 and the outermost layer 7
12 has a maximum pore diameter of 0.2 μm or less and a porosity of 25% or more and 50% or less, so that when the porosity is less than 25%, the air permeability exceeds the above numerical range. When the porosity exceeds 50%, the air permeability is prevented from falling below the above numerical range. Further, in the present invention, it is possible to prevent the particles such as toner from adhering easily, as in the case where the maximum pore diameter exceeds 0.2 μm.

The air permeability of the innermost layer 5 and the outermost layer 7 is 500
Since the air permeability is more than 30000 sec / 100 cc, when silicone oil is applied to the fixing belt and used, as in the case where the air permeability exceeds 30000 sec / 100 cc, the inside of the through-hole 12 of the outermost layer 7 The effect of the through-holes 12 does not decrease, for example, the silicon oil hardly penetrates and the content decreases, and the air permeability is 500 seconds / 10
The resin forming the outermost layer 7 does not excessively invade the through-hole as in the case of exceeding 0 cc. Therefore, the outermost layer 7 enters into the tube body with an appropriate degree of penetration and a sufficiently high adhesive force, and at the same time, retainability of the silicone oil is improved.

The first and second primer layers 8 and 10 of the tubular main body 6 are made of, for example, fluorine rubber or silicon rubber and have elasticity. The material constituting the first and second primer layers 8 and 10 has a lower softening point and a lower melting point than the PTFE of the innermost layer 5 and the outermost layer 7, and is lower than that of the thermosetting synthetic resin layer 9. Good compatibility with the inner layer 5 and the outermost layer 7.

The first and second primer layers 8 and 10 are formed of a resilient fluorine rubber or silicone rubber. When used as a fixing belt in this way, softness is imparted to the fixing pressure, and color mixing, especially during thermal melting of the color toner, progresses, and the image quality is improved. As the primer layers 8 and 10, silicone rubber is particularly preferable because it is softer. This is the same for the primer layer 23 shown in FIGS.

The thermosetting synthetic resin layer 9 of the cylindrical body 6
May be a cross-linkable resin, for example, a fluorine resin, an imide resin, or a polyethersulfone (PES) resin. Can be enhanced.
Therefore, the innermost layer 5 made of PTFE resin having high heat resistance
And the outermost layer 7, and the first and second primer layers 8, 10
The layer 9 is combined with the layer 9 to form the cylindrical body 1 and can be suitably used as a fixing belt or the like that requires high heat resistance.

The synthetic resin constituting the thermosetting synthetic resin layer 9 may be a fluororesin as described above. For example, a fluorine-based compound as a main agent and a curing agent which reacts with a functional group of the main agent may be used. Consists of Zeffle GK-500 (trade name: manufactured by Daikin Industries), Zeffle GK-510 (trade name: manufactured by Daikin Industries), Lumiflon LF-200 (trade name: manufactured by Asahi Glass), Lumiflon LF- 400 (trade name: manufactured by Asahi Glass), Fluonate K-700 (trade name: manufactured by Dainippon Ink), Zafflon FC-110 (trade name: manufactured by Toa Gosei),
One of Zaflon FC-220 (trade name: manufactured by Toagosei Co., Ltd.) and Safral Coat (trade name: manufactured by Central Glass) may be used. As the curing agent, one of isocyanate, melamine, and blocked isocyanate may be used.

The synthetic resin constituting the thermosetting synthetic resin layer 9 may be an imide resin as described above.
This imide resin is one of a polyimide resin, a polyamino bismaleimide resin and a polyamide imide resin.
It may be one.

The innermost layer 5 or the outermost layer 7 has an outer diameter of 10 m.
m to 200 mm and a thickness of 50 μm to 20
It is a seamless tubular shape having a diameter of 0 μm or less.

The innermost layer 5 or the outermost layer 7 has such an outer diameter, so that the outer diameter is less than 10 mm and 1 mm.
As in the case where the diameter exceeds 00 mm, it is not difficult to manufacture the above-described straight cylindrical mold for expanding and expanding the innermost layer 5 to make it difficult to manufacture, and it is possible to manufacture easily and inexpensively. When the outer diameter is less than 10 mm, it is difficult to form the innermost layer 5 and the cylindrical main body 6 in the outermost layer 7, and when the outer diameter exceeds 100 mm, the outer peripheral surface of the innermost layer 5 becomes large. It is difficult to apply the resin uniformly, and it is difficult to form the cylindrical main body 6 having a uniform thickness. On the other hand, in the present invention, since the outer diameter is 10 mm or more and 200 mm or less, the cylindrical main body 6 having a uniform thickness can be formed.

The cylindrical body 1 has a thickness of 50 μm or more and 20 μm or more.
Since the thickness is 0 μm or less, the thickness does not become too thin as in the case where the thickness is less than 50 μm and the durability does not decrease, and the thickness does not become too thick and the rigidity becomes too high as in the case where the thickness exceeds 200 μm. Therefore, it is possible to obtain the cylindrical body 1 which has sufficient durability and can easily change the curvature partially, and can be suitably used as a fixing belt.

The ratio of the thickness t of the cylindrical body 1 to the outer diameter D1 (t
/ D1) is from 1/50 to 1/1000, preferably from 1/100 to 1/500. For example, the thickness of the cylindrical body 1 is 0.4 mm / outside diameter 20 mmφ to 0.2 mm / outside diameter 200 mmφ, that is, the ratio (t / D1) = 1/50.
１／1/100, preferably 0.2 mm / outer diameter 20 mmφ to 0.4 mm / outer diameter 200 mmφ, and the ratio (t / D1) = 1 / 100〜1 / 500.

Regarding the mechanical strength of the cylindrical body 1, the cylindrical body 1
Is 2.5 kg or more per 1 cm of width in the axial direction. The tensile yield stress σy in the circumferential direction of the tubular body 1 is 150 kgf / cm ² or more.
Furthermore, the tensile elastic modulus E in the circumferential direction of the cylindrical body 1 is 7000
kg weight / cm ² or more.

The cylindrical body 1 has the mechanical strength with respect to the tension in the circumferential direction as described above, and the fixing belt 3 such as a copying machine as described above has an axial width in the circumferential direction. A load of 2.5 kg or more per cm is not applied, and a tensile load generating a tensile stress of 150 kg / cm ² or more is not applied. Therefore, the cylindrical body 1 has high durability as a fixing belt. It can be suitably used with good properties. Further, the fixing belt is not subjected to a tensile load which greatly changes the circumferential dimension of the belt having the above-described tensile elasticity coefficient.
Can be used as a fixing belt in a suitable state with low elongation.

FIG. 2 is a view showing a method for manufacturing the cylindrical body 1 shown in FIG. 1, and FIG. 3 is a cross-sectional view for explaining a manufacturing process of the cylindrical body 1. Step a in FIG.
In 1, first, a PTFE raw tube is manufactured from a pasty material by extrusion molding. This original tube is indicated by reference numeral 14 in FIG.

Next, in step a2 of FIG.
Is inserted into a straight cylindrical mold, and one end in the axial direction of the original tube 14 is fixed to the mold. The original tube 14 is heated together with the mold to a state in which the temperature is increased to an expansion processing temperature equal to or higher than the softening point and lower than the melting point of PTFE as a material thereof, for example, 250 to 310 ° C. In this heated state, a compressed gas such as compressed air is supplied from the one end of the original tube 14, whereby the original tube 14 expands radially outward in the mold and the other end of the original tube 14. The part expands and expands to a predetermined axial position by the stopper. After being expanded in this way, it is cooled in a pressurized state, that is, in an expanded state, and a porous molded product 15 shown in FIG. 3B is obtained in step a2 in FIG.

In the next step a3, the molded product 15 shown in FIG. 3 (2) is put on a core metal 16 which is an insertion mold shown in FIG. 3 (3). Core 1 inserted into molded product 15
6 is, for example, a straight cylindrical tube made of aluminum.

With the core metal 16 inserted into the molded product 15 as described above, the temperature is raised to a temperature (for example, less than 390 ° C.) that is equal to or higher than the expansion processing temperature and lower than the temperature at which the decomposition of the PTFE resin remarkably occurs. To form the innermost layer 5. Thus, the porous innermost layer 5 in which the through-holes 11 whose inner surface shapes change as described above is uniformly scattered is obtained.

As shown in FIG. 3 (3), when the molded product 15 is in close contact with the outer peripheral surface of the cored bar 16 by thermal contraction, the amount of contraction is relatively small. The large number of through-holes 11 of the innermost layer 5 formed as they are are kept as they are, and the porous characteristics do not deteriorate. In forming the innermost layer 5, both ends of the molded product 15 that remain unexpanded and have a small diameter, and thus both outer portions of the intermediate expanded portion, may be cut off before the heat setting process. .

In step a5, the first primer layer 8 is applied in a solution state to the outer peripheral surface of the innermost layer 5 formed on the cored bar 16. When applying the resin for forming the first primer layer 8, the outer peripheral surface of the innermost layer 5 may or may not be subjected to a pretreatment. As the lower treatment, it is preferable to perform a defluorination treatment,
The applied resin can be easily applied to the innermost layer 5, so that the applied resin is prevented from being repelled and can be easily attached. In this way, the affinity for the interface can be improved, and stronger adhesion of the layer 8 can be achieved. The defluorination treatment can be performed by etching using metallic sodium.

When a resin for forming the first primer layer 8 is applied to the outer peripheral surface of the innermost layer 5, this resin penetrates into each through hole 11 and is cured in this state. The resin forming the first primer layer 8 is applied in a solution state, that is, with a low viscosity that is easy to flow, so that the resin easily enters the through holes 11. Even when applied in such a solution state, the solvent is dried,
By volatilizing, the resin can be cured by a curing agent. In this way, the first primer layer 8 is
1 is formed in a state in which it has entered. Thus, the first primer layer 8 penetrates into the through-holes 11 of the innermost layer 5, and the first primer layer 8 and the innermost layer 5 are firmly engaged with each other, so that the anchor effect is achieved. One primer layer 8 is strongly adhered. Since the through-holes 11 are scattered at a uniform density on the outer peripheral surface of the innermost layer 5, the adhesive force with the first primer layer 8 is uniform, and local peeling is reliably prevented.

The innermost layer 5 has a seamless cylindrical shape, the outer peripheral surface is uniform, and a uniform first primer layer 8 can be easily formed by applying a uniform resin. Moreover, since the innermost layer 5 is porous, by applying a resin,
The resin is allowed to enter the through holes 11 to prevent the resin from being repelled, and the resin is cured in this state to form the first primer layer 8.

Since the first primer layer 8 is formed by applying a resin to the innermost layer 5 as described above, the first primer layer 8 is formed.
Can be uniformly and easily applied, and a uniform first primer layer 8 can be easily formed. Therefore, the cylindrical body 1 can be easily and inexpensively manufactured.

As described above, the innermost layer 5 is formed by forming the raw material cylinder 14 by paste extrusion molding.
Is formed by expanding and heat-setting the innermost layer 5, so that the innermost layer 5 having the above-described characteristics in which the through holes are uniformly formed can be manufactured. Therefore, the cylindrical body 1 in which the cylindrical main body 6 having a uniform thickness is formed by applying the resin can be easily manufactured. The innermost layer 5 may be subjected to a defluoridation treatment on the outer peripheral surface on which the first primer layer 8 is formed. In this case, the resin forming the first primer layer 8 is easily applied to the innermost layer 5 and is applied. Occasionally, repelling is prevented and adhesion is facilitated, so that this coating operation is facilitated, and the first primer layer 8 having a uniform thickness can be easily formed. In addition, by improving the interfacial affinity in this way, stronger adhesion can be achieved. In addition, since the resin forming the first primer layer 8 is applied in the form of a solution dissolved in a solvent, the viscosity can be reduced to facilitate penetration into the through holes 11. Therefore, the cylindrical body can be easily formed. Although the above description has been made mainly with reference to the innermost layer 5, the same applies to the outermost layer 7 and the inner peripheral surface of the outermost layer 7.

After the formation of the first primer layer 8, in step a6 of FIG. 2, a thermosetting synthetic resin layer 9 is formed by applying a solution. The solvent of the thermosetting synthetic resin is dried and volatilized to harden the resin.

On the outer peripheral surface of the thermosetting synthetic resin layer 9,
In step a7 of FIG. 2, the second primer layer 10
It is formed by being applied in a solution state. The solvent of the second primer layer is dried and volatilized to cure the resin.

Further, in step a8, a porous tubular PTFE outermost layer 7 is covered on the outer peripheral surface of the second primer layer 10. In a state where the outermost layer 7 is covered, the temperature is equal to or higher than the melting temperature of the second primer layer 10, that is, 230 to 25.
The outermost layer 7 is shrunk at a temperature of 0 ° C. or higher and lower than the melting point of PTFE and shrinks by heat in step a9 in FIG. By this heating, the second primer layer 10
It penetrates into many through-holes 12 of the outermost layer 7, and its anchor effect improves the bonding strength. The contraction amount of the outermost layer 7 is relatively small, and the porosity of the through-hole 12 is maintained.

The material of the innermost layer 5 and the outermost layer 7 is PT
Instead of FE, a fluororesin such as a perfluoroalkylvinylether copolymer resin (abbreviated as PFA) may be used.

FIG. 4 is a partial cross-sectional view of another embodiment of the present invention. This embodiment is similar to the embodiment of FIGS. 1 to 3 described above, and corresponding parts are denoted by the same reference numerals. In the embodiment shown in FIG. 4, a tubular main body 6 is formed on the outer peripheral surface of the innermost layer 5 in the same manner as in the above-described embodiment, and the above-described steps a1 to a7 in FIG. . In this embodiment, the outermost layer 17 made of a straight cylindrical PTFE is then provided on the second primer layer 10 of the cylindrical main body 6.
Is covered. The outermost layer 17 is formed, for example, as shown in FIG.
The original tube 14 shown in (1), in which many through holes are not formed, is not porous. Prior to covering the outermost layer 17 on the second primer layer 10, the inner peripheral surface of the outermost layer 17 is subjected to a defluorination treatment. Thus, the outermost layer 17 which is not porous and whose inner peripheral surface is defluorinated is put on the outer peripheral surface of the second primer layer 10 as described above.

Thus, the outermost layer 17 is formed on the second primer layer 10.
Is heated to a temperature that is higher than the melting point of the second primer layer 10 and that causes the outermost layer 17 to thermally contract. As a result, the second primer layer 10 comes into close contact with the inner peripheral surface of the outermost layer 17 so that a large adhesive strength can be obtained.

In another embodiment of the present invention, FIGS.
In the embodiment shown in FIG. 2, the inner peripheral surface of the outermost layer 7 is subjected to a defluorination treatment in advance, and in step a8 of FIG.
Covering the outermost layer 7 with the second primer layer 10, step a9
May be subjected to a heat treatment.

In still another embodiment of the present invention, FIG.
In step a3 or a4, the outer peripheral surface of the innermost layer 5 may be subjected to a defluorination treatment in advance, and the first primer layer 8 may be applied thereon in a solution state. According to such an embodiment, since the innermost layer 5 and the outermost layer 7 are porous, the anchor effect is achieved and the adhesive strength is improved, and the adhesive strength is also improved by the defluorination treatment.

In another embodiment of the present invention, the outer peripheral surface of the innermost layer 5 in FIG. 4 may also be subjected to a defluorination treatment.

In still another embodiment of the present invention, FIG.
As the outermost layer 17, PFA may be used instead of PTFE. The outermost layer 17 made of such PFA is also used as the outermost layer 7 described above with reference to FIGS. It may be made porous by expanding and expanding the diameter by heating at the above temperature.

FIG. 5 is a sectional view of a part of a cylindrical body 1b according to another embodiment of the present invention. This embodiment is similar to the above-described embodiment, and corresponding portions are denoted by the same reference numerals. On the outer peripheral surface of the innermost layer 5, a cylindrical main body 21 is formed. The tubular main body 21 includes, on the outer peripheral surface of the innermost layer 5, a thermosetting synthetic resin layer 22 having an adhesive strength improved by an anchor effect of the innermost layer 5, and a primer layer 23 formed on the layer 22. including.

FIG. 6 is a flowchart for explaining a method of manufacturing the cylindrical body 1b shown in FIG. Steps b1 to b4 in FIG. 6 correspond to steps a1 to a4 in FIG.
Is the same as In step b5, the thermosetting synthetic resin layer 22 is applied to the outer peripheral surface of the innermost layer 5 in a solution state. The solvent of the thermosetting synthetic resin is dried and volatilized, and the resin is cured.

On the outer peripheral surface of the thermosetting synthetic resin layer 22, a primer layer 23 is applied in a solution state and cured in step b6 of FIG. The subsequent steps b7 and b8 in FIG. 6 correspond to step a in FIG.
Same as 8, a9. That is, the outermost layer 7 made of porous PTFE is put on the primer layer 23 and heated at a temperature equal to or higher than the melting temperature of the primer layer 23 to thermally shrink the outermost layer 7. In this way, the primer layer 23 penetrates into the large number of through holes 12 of the outermost layer 7, thereby achieving the anchor effect, and improving the adhesive strength.

In another embodiment of the present invention, the outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 may be defluorinated. In still another embodiment of the present invention, instead of the porous outermost layer 7 of FIG. 5, an outermost layer in which a large number of through holes are not formed, that is, a nonporous outermost layer may be used. May be PTFE or alternatively PF
A fluorine resin such as A may be used.

FIG. 7 is a partial cross-sectional view of another embodiment of the present invention. The tubular body 1c is similar to the tubular body 1b shown in FIG. 5 described above, and corresponding portions are denoted by the same reference numerals. It should be noted that in this embodiment, the outermost layer 17 is
This is similar to the configuration of FIG. 4 described above, and is formed by covering with a non-porous PTFE outermost layer whose inner peripheral surface has been defluorinated, and thermally contracted by heating. Other configurations are similar to the above-described embodiments.

FIG. 8 is a simplified cross-sectional view of the fixing device 2 in the electrophotographic image forming apparatus according to one embodiment of the present invention. A toner image 26 is formed on the recording paper 25, is conveyed in a conveying direction 27, and is brought to the fixing device 2. In the fixing device 2, the fixing belt 3 is elastically pressed against the fixing roll 28 by the pressing piece 29. The fixing roll 28 is driven to rotate in the direction of arrow 31 by a driving source. The recording paper 25 is fixed between the fixing roll 28 and the fixing belt 3.
Is pinched. The fixing roll 28 is heated by the heat source 32. The recording paper 25 is composed of the fixing roll 28 and the fixing belt 3.
The toner image 26 is melted by heat and adheres to the recording paper 25 to be fixed.

The fixing belt 3 elastically pressed by the pressing piece 29 against the fixing roll 28 is driven by the driving of the fixing roll 28. As the fixing belt 3, the tubular body 1 shown in FIG. 1 described above is used. FIG. 1 of this fixing belt 3
Since the outermost layers 7, 17 shown in FIG.
The releasability of the toner image 26 is good, and the outermost layers
7 is not soiled. Further, the innermost layer 5 is also made of fluororesin, so that the frictional resistance with the pressing piece 29 is small, and the fixing belt 3 can be smoothly rotated following the fixing roll 28. The fixing roll 28 has a layer 33 having elasticity.

The fixing belt 3 may use the cylindrical members 1a, 1b, and 1c of the respective embodiments shown in FIGS. 4, 5, and 7, and further include other cylindrical members having the above-described configuration. A body may be used.

The experimental results of the present inventor will be described. In the above-described embodiment of the present invention shown in FIGS. 1 to 3, the molded product 15 to be used as the innermost layer 5 shown in FIG. 3 (2) is made of PTFE and is porous. The inner diameter is 31 ± 0.5 mmφ and the thickness is 100 ± 20 μm. The core 16 shown in FIG. 3 (3) is made of stainless steel or brass, and has an outer diameter of 30 mmφ, a thickness of 2 mmt, and a length of 400 mm. In the state of FIG. 3C, the temperature 350 at which the innermost layer 5 is heat-set at step a4 of FIG.
C. × time 30 min. To form the first primer layer 8 on the outer peripheral surface of the innermost layer 5, the first primer layer 8
Is a solution using butyl acetate, which is commercially available as NF732 (trade name, manufactured by Daikin Industries, Ltd.) as a solvent. At this time, the heating and drying temperature was 250
C. × 30 min.

In order to form the thermosetting synthetic resin layer 9, RC5057 (trade name of IST) as a polyimide resin was prepared as a solution using the solvent N-methylpyrrolidone.
The application amount of 3 g / time was repeated 5 times to obtain a film thickness of 30 μm. At this time, the heating and drying temperature of the solvent was 250 ° C. × 30 m.
in was repeated each time, and a total of 5 applications were applied. Thus, the layer 9 was formed.

The solution of the second primer layer 10 was applied on the outer peripheral surface of the layer 9, and the solvent was dried and evaporated to form the second primer layer 10. The second primer layer 10 was formed in the same manner as the first primer layer 8 described above.

The molding 15 used as the outermost layer 7 is
It has the same configuration as that shown in FIG.
At the time of forming the outermost layer 7, the temperature was 350 ° C. × time 30 minutes, and the final outer diameter of the outermost layer 30 ± 0.3.
It is 3 mmφ and 350 mm in length. The tubular body 1 thus obtained remains inserted through the metal core 16.

Thereafter, the tubular body 1 is removed from the metal core 16. The compressed air pressure used at this time is 3.0 kgf /
cm ² and a flow rate of 100 L / min.

In order to impart conductivity to the thermosetting synthetic resin layer 9, the first and second primer layers 8, 10
In order to impart electrical conductivity, 2 to 10% by weight of carbon powder is mixed. The carbon powder is commercially available, for example, under the trade name MA600 manufactured by Mitsubishi Chemical Corporation. As for this conductivity, a volume resistance value of 10 ⁴ to 10 ¹⁰ Ω · cm is preferable. To impart conductivity to the innermost layer 5, PT
Carbon powder is mixed with FE. This carbon powder is commercially available under the trade name FPG5010 manufactured by Daikin Industries. Since the innermost layer 5 has conductivity, excessive charge generated when the tubular body 1 is used as a fixing belt is discharged by being grounded by a conductive pressing piece 29 made of metal or the like that comes into contact with the innermost layer 5. be able to.

The other experimental results of the present inventor will be described. FIG.
In the above embodiment shown in FIG. 6 and FIG. 6, when a fluororesin is selected as the synthetic resin forming the thermosetting synthetic resin layer 22, Zeffle GK-51 as the main agent is used.
0 (fluorine resin paint: trade name: manufactured by Daikin Industries) 50
% Of butyl acetate (solvent) 50% by weight solution X1 and isocyanate curing agent Coronate HX (trade name: Nippon Polyurethane Industry Co., Ltd.) Y1, 100 parts by weight of solution X1 and 12 parts by weight of curing agent Y1 , And butyl acetate was added to the mixture at a ratio of 100 parts by weight of the mixture and 20 parts by weight of butyl acetate, and the mixture was diluted and prepared. The prepared coating agent (a solution of a resin for forming a coating layer) is sufficiently contained in a gauze, and the gauze is allowed to pass through the inside of the cylindrical body obtained as described above, and the coating agent is applied to the outer peripheral surface of the innermost layer 5. It was applied to the entire surface. Next, infrared rays were irradiated for 2 hours under an infrared lamp to dry the solvent and thereby cure the resin (by the reaction between the functional group of the main component and the curing agent). Innermost layer 5
A coating layer having a thickness of 0.03 mm was formed of a fluororesin on the outer peripheral surface of the substrate.

In another embodiment of the present invention, the synthetic resin forming the thermosetting synthetic resin layer 22 is an imide resin, and HI-60, which is a solution of polyamideimide before curing, is used.
0A (trade name: manufactured by Hitachi Chemical) with N-methylpyrrolidone,
100 parts by weight of the polyamide resin solution and 15 parts by weight of N-methylpyrrolidone were added, diluted and mixed. The coating agent obtained by the preparation was applied to the defluoridated outer peripheral surface in the same manner as in the case of the fluororesin. By performing the defluoridation treatment, repelling of the coating agent, specifically N-methylpyrrolidone, could be prevented, and the coating agent could be suitably applied. Next, 1
After that, the film was left to stand in an atmosphere of 300 ° C. for 30 minutes, heated and cured. A layer 22 having a thickness of 0.03 mm made of polyamide-imide resin on the outer peripheral surface of the innermost layer 5
Was formed.

The resin forming the layer 22 is a PES resin,
N-methylpyrrolidone was added to PES100P (trade name: manufactured by Sumitomo Chemical Co., Ltd.), a solution of PES resin for coating, and PES
100 parts by weight of resin solution and 1 part of N-methyl-2-pyrrolidone
It was added at a ratio of 5 parts by weight, diluted and blended. The coating agent obtained by the preparation was applied to the defluorinated inner peripheral surface in the same manner as in the case of the imide-based resin. By performing the defluorination treatment, the coating agent could be suitably applied similarly to the case of the imide-based resin. Next, it was cured by being left to stand in an atmosphere of 200 ° C. for 30 minutes, and subsequently in an atmosphere of 250 ° C. for 30 minutes. Layer 2 having a thickness of 0.03 mm made of PES resin on the outer peripheral surface of innermost layer 5
2 was formed.

In another embodiment of the present invention, the layer 22 made of thermosetting synthetic resin is Kapton (trade name: manufactured by DuPont).
Pyromellitic dianhydride represented by
A layer 22 made of a polyimide resin may be formed by applying a polyamic acid solution using diaminophenyl ether as a raw material, penetrating into and impregnating the through-holes, and then heating and curing. Also, a bismaleimide varnish made from diaminophenylmethane and maleic anhydride typified by kerimide (trade name: made by Rhone Poulin) is applied, penetrated into the through-holes, impregnated with heat, and then cured by heating to form polyamino. A layer 22 made of a bismaleimide resin may be formed. Furthermore, a layer 22 made of a wholly aromatic polyimide may be formed by applying a wholly aromatic polyimide varnish (trade name: manufactured by Toray Industries Inc.), penetrating into and impregnating the through-holes, and then heating and curing. It is also possible to form the layer 9 described above on the first primer layer 8 in a similar manufacturing process to these layers 22.

[0112]

According to the present invention, the innermost layer 5 and the outermost layer 7,
Reference numeral 17 denotes a fluororesin, which is formed on the cylindrical main bodies 6 and 21 with improved adhesive strength, so that the durability can be improved, and is particularly used for a fixing device in an electrophotographic image forming apparatus. In the fixing belt 3, the adhesive strength between the innermost layer and the cylindrical body and the adhesive strength between the cylindrical body and the outermost layer are high in a relatively high temperature environment where the toner is softened and melted. There is no danger. Thus, a cylindrical body having excellent durability is realized. Thermosetting synthetic resin layers 9, 22 constituting at least a part of the cylindrical main body
Has a stable shape without deformation even in a high temperature environment, and is useful for improving the strength of the cylindrical body.

The innermost layer 5 and / or the outermost layer 7 are porous, and the tubular body enters into the large number of through holes 11 and 12 to exert an anchoring effect, thereby improving the adhesive strength. Also, the outer peripheral surface of the innermost layer 5 facing the cylindrical main body and / or
Alternatively, the inner peripheral surfaces of the outermost layers 7, 17 are defluoridated,
Therefore, the familiarity with the cylindrical main bodies 6, 21 is good,
When the cylindrical body is applied in a molten state, it is prevented from being repelled and easily adhered, and thus the interface affinity is improved. This also improves the adhesive strength.

Further, according to the present invention, the cylindrical main bodies 6, 2
1, and furthermore, the innermost layer 5 has conductivity, so that when the tubular body of the present invention is used, for example, as a fixing belt or the like, it is easy for undesired charges to be discharged. It is possible to prevent the inconvenience that the toner on the recording paper scatters due to the bad influence of the electric charge and the fixed image quality is deteriorated.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a part of a tubular body 1 according to one embodiment of the present invention.

FIG. 2 is a view showing a method for manufacturing the tubular body 1 shown in FIG.

FIG. 3 is a cross-sectional view for explaining a manufacturing process of the tubular body 1 shown in FIG.

FIG. 4 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a part of a cylindrical body 1b according to another embodiment of the present invention.

FIG. 6 is a flowchart illustrating a method of manufacturing the cylindrical body 1b shown in FIG.

FIG. 7 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 8 is a simplified cross-sectional view of the fixing device 2 in the electrophotographic image forming apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b, 1c Cylindrical body 2 Fixing device 3 Fixing belt 5 Innermost layer 6, 21 Cylindrical body 7, 17 Outermost layer 8 First primer layer 9, 22 Thermosetting synthetic resin layer 10 Second primer layer 11, 12 Through hole 14 Raw tube 15 Molded product 16 Core metal 23 Primer layer 25 Recording paper 26 Toner image 27 Transport direction 28 Fixing roll 29 Pressing piece 32 Heat source

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Ryohei Matsui 6-2 Imakunifu-cho, Yamatokoriyama-shi, Nara Prefecture F-term (reference) 2H033 BA11 BB01 BB29 BB30 3J103 AA02 AA14 FA12 GA02 GA57 GA58 HA04 HA18 HA41 4F100 AB10 AH03 AK01C AK17A AK17C AK17E AK18A AK18E AK49C AK50 AK80C AN02B AN02D AR00B AR00D BA03 BA05 BA07 BA10A BA10E CA02 DA11 DJ00A EH17 EH46 EJ42 EJ48 JL11 JB13L00JL11

Claims (26)

[Claims] An innermost layer made of a fluororesin and a cylindrical main body formed on the outer peripheral surface of the innermost layer with improved adhesive strength and having at least a thermosetting synthetic resin layer.
And a fluorocarbon resin outermost layer (7, 17) formed on the outer peripheral surface of the cylindrical main body with improved adhesive strength. 2. The tubular main body 6 includes: a first primer layer 8 formed on an outer peripheral surface of an innermost layer; a thermosetting synthetic resin layer 9 formed on an outer peripheral surface of the first primer layer; The cylindrical body according to claim 1, further comprising a second primer layer (10) formed on an outer peripheral surface of the thermosetting synthetic resin layer. 3. The cylindrical body according to claim 2, wherein the innermost layer is porous, and the first primer layer is formed so as to penetrate into the through holes of the innermost layer. . 4. The cylinder according to claim 2, wherein the outermost layer is porous, and the second primer layer is formed in a state of invading each of the through holes of the outermost layer. Shape. 5. A tubular main body comprising: a thermosetting synthetic resin layer formed on the outer peripheral surface of the innermost layer; and a primer layer formed on the outer peripheral surface of the thermosetting synthetic resin layer. 23. The cylindrical body according to claim 1, comprising: 6. The innermost layer 5 is porous, and the thermosetting synthetic resin layer 22 is formed in a state in which it penetrates each through hole 11 of the innermost layer. Cylindrical body. 7. The cylindrical body according to claim 5, wherein the outermost layer is porous, and the primer layer is formed in a state of invading each of the through holes of the outermost layer. . 8. One of claims 3, 4, 6 and 7, wherein at least one of the outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 is subjected to a defluorination treatment. 3. The tubular body according to 1. 9. The method according to claim 1, wherein at least one of the outer peripheral surface of the innermost layer 5 and the inner peripheral surface of the outermost layer 7 is smooth and defluorinated. The cylindrical body according to any one of the above. 10. The fluororesin of the innermost layer 5 and the outermost layer 7 is made of a polytetrafluoroethylene resin, has an outer diameter of 10 mm or more and 200 mm or less, and has a seamless cylindrical shape having a thickness of 50 μm or more and 200 μm or less, The porosity is such that the maximum pore size is 0.2 μm or less and the porosity is 2 μm.
5% or more and 50% or less, and the air permeability is 500 seconds / 100
The cylindrical body according to any one of claims 1 to 9, wherein the surface roughness is not less than cc and not more than 30,000 seconds / 100 cc, and the surface roughness is not more than 0.5 µm as a center line average roughness Ra. 11. The tubular body according to claim 1, wherein the innermost layer and the outermost layer are a polytetrafluoroethylene resin or a perfluoroalkyl vinyl ether resin. 12. The tubular body according to claim 1, wherein the thermosetting synthetic resin is a fluororesin, an imide-based resin, or a polyethersulfone resin. 13. The tubular body according to claim 2, wherein the primer is a fluoro rubber or a silicone rubber. 14. A ratio (t / D) between the thickness t and the outer diameter D1.
14. The tubular body according to claim 1, wherein 1) is 1/50 to 1/1000. 15. A ratio (t / D) between the thickness t and the outer diameter D1.
The cylindrical body according to claim 14, wherein 1) is 1/100 to 1/500. 16. The tubular body according to claim 1, wherein the tubular bodies include a conductive layer. 17. The cylindrical body according to claim 16, wherein the thermosetting synthetic resin layers 9, 22 or the primer layers 8, 10, 23 have conductivity. 18. The tubular body according to claim 1, wherein the innermost layer has conductivity. 19. The conductivity means a volume resistance value of 1
0 ⁴ claim 1, characterized in that the ~10 ¹⁰ Ω · cm
The tubular body according to one of 6 to 18. 20. The cylindrical body according to claim 1, wherein a tensile yield load in a circumferential direction is at least 2.5 kg weight per 1 cm of an axial width. 21. A tensile yield stress in a circumferential direction of 150 kg
Weight / cm ² or more.
The tubular body according to any one of the above. 22. A tensile modulus in the circumferential direction is 7000 k.
g weight / cm ² or more.
A tubular body according to one of the preceding claims. 23. A cylindrical main body 6, 21 formed by applying a solution in the form of a solution on the outer peripheral surface of the innermost layer 5 made of polytetrafluoroethylene resin. Resin layers 9, 2
2. Primer layers 10 and 23 are formed on the outer peripheral surface of No. 2, and a polytetrafluoroethylene resin porous outermost layer 7 is
A method for producing a tubular body, wherein the outermost layer 7 is thermally shrunk by heating to a temperature higher than the melting point of the primer layers 10 and 23 in a state of covering the outer peripheral surfaces of the primer layers 10 and 23. 24. On the outer peripheral surface of the innermost layer 5 made of polytetrafluoroethylene resin, a cylindrical main body 6, 21 is formed by applying a solution, and the cylindrical main body 6, 21 is formed by thermosetting synthetic resin. Resin layers 9, 2
The outermost layers 7 and 17 made of polytetrafluoroethylene resin whose inner peripheral surfaces are defluorinated are formed on the outer peripheral surfaces of the primer layers 10 and 23.
A method for producing a cylindrical body, comprising heating the outermost layer by heating above the melting point of the primer layers 10 and 23 while covering the outer peripheral surface of the cylindrical body. 25. The innermost layer 5 is formed by forming a raw material cylinder by paste extrusion molding, and expanding the raw material cylinder at least in the radial direction at an expansion processing temperature not lower than the softening point but lower than the melting point to be porous. The expanded raw material cylinder is formed by heat-setting at a temperature equal to or higher than the expansion processing temperature and lower than the temperature at which the decomposition of the polytetrafluoroethylene resin occurs remarkably, while being porous. 25. The method for producing a cylindrical body according to 23 or 24. 26. A toner image carried on a recording medium,
A fixing belt for fixing by heating and pressing, wherein the fixing belt is the cylindrical body according to any one of claims 1 to 22.