JPH06198781A - Manufacture of composite tubular matter - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for composite tubular matter, which is excellent in workability and with which fluoroplastic tubular outer layer with uniform thickness can be produced. CONSTITUTION:Support, the outer diameter of which is smaller than the inner diameter of polyimide resin tubular matter and which is prepared by covering the outer peripheral surface of mandrel 13 with elastic sleeve 12 under the condition that gap is provided between the sleeve 12 and the mandrel 13, is inserted in the interior of the polyimide resin tubular matter so as to diametrically expand the elastic sleeve 12 by introducing fluid between the mandrel 13 and the elastic sleeve 12 of the support in order to bring the sleeve in closely contact with the inner peripheral surface of the polyimide resin tubular matter, resulting in supporting the polyimide resin tubular matter from its inner peripheral surface side. After that, under the above-mentioned supported state of the polyimide resin tubular matter, fluoroplastic tubular outer layer is formed on the outer peripheral surface of the polyimide resin tubular matter. Then, by discharging the fluid between the diametrically expanded elastic sleeve 12 and the mandrel 13 of the support, the support is retracted diametrically so as to take the support out of the interior of the polyimide resin tubular matter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite tubular article used as a fixing belt for an image forming apparatus such as a copying machine, a facsimile, a printer or the like.

[0002]

2. Description of the Related Art In an image forming apparatus, for example, a heat roller fixing method is known as a method of fixing an image on a transfer sheet and has been used conventionally. As shown in FIG. 4, this heat roller fixing method uses heat roller 1 and press roller 2
Are vertically opposed to each other, the transfer paper 3 is fed between the rollers 1 and 2, and the heat-sensitive ink 5 temporarily attached to the transfer paper 3 is melted and fixed by the heat generated by the heater 4 built in the heat roller 1. At the same time, pressure is applied by the press roller 2 to further strengthen the fixing. By this method,
An image 6 is formed on the transfer paper 3 with the thermal ink 5.
In this heat roller fixing method, in order to melt and fix the heat sensitive ink on the transfer paper, it is necessary to raise the surface temperature of the heat roller to a predetermined temperature which is equal to or higher than the melting temperature of the heat sensitive ink. For this reason, for example, in a copying machine, after turning on the power, a waiting time of 20 seconds to 10 minutes usually occurs until the surface temperature of the heat roller reaches the above-mentioned predetermined temperature, and there is an inconvenience that the copying operation cannot be performed. Therefore, in order to reduce the waiting time, a method of using a fixing belt instead of the heat roller has been proposed and partially implemented. As shown in FIG. 5, the fixing belt 10 is stretched over the rollers 7 and 8 and the heater 9, and the pressing roller 2 is arranged so as to face the heater 9, and the heat-sensitive ink 5 is temporarily attached. The transferred transfer paper 3 is fed between the belt 10 and the roller 2, and the heat-sensitive ink 5 is melted and fixed to form an image 6. Since this fixing belt has a smaller thickness and a smaller heat capacity than the heat roller, the heat generated by the heater is immediately transmitted to the belt. Therefore, when the power is turned on, the surface temperature of the fixing belt immediately rises to a predetermined temperature, which has the advantage of significantly shortening the waiting time.

[0003]

As such a fixing belt, a tubular article made of a polyimide resin excellent in heat resistance and mechanical strength, or a tubular inner layer made of a polyimide resin and a fluororesin formed on the outer peripheral surface of the inner layer are used. A composite tubular article including a tubular outer layer has been proposed (JP-A-3-13).
No. 0149). In particular, the above-mentioned composite tubular article has excellent properties such as heat resistance and abrasion resistance, and is therefore prized.
This composite tubular product is obtained by spray coating a fluororesin solution or a fluororesin dispersion onto the outer peripheral surface of a polyimide resin tubular product to form a fluororesin tubular outer layer. At the time of this spray coating, since the above-mentioned polyimide resin tubular product is usually weak, it is necessary to insert and support a support inside the polyimide resin tubular product. As such a support, a columnar or cylindrical support is known. The support using these supports must be in a state in which the outer peripheral surface of the support and the inner peripheral surface of the polyimide resin tubular article are in complete contact. That is, when not completely adhered, the polyimide resin tubular article is distorted by the pressure of the liquid or the droplets of the fluororesin solution or the like during spray coating, and the fluororesin tubular outer layer having an uneven thickness. Is formed. When the composite tubular article having the fluororesin tubular outer layer of this nonuniform thickness is used as the fixing belt, the heat conduction becomes nonuniform, and as a result, there arises a problem that the resulting image is shaded. Therefore, it is necessary to make the outer diameter of the support the same as the inner diameter of the tubular product made of the polyimide resin. However, when such a support is used, it becomes extremely difficult to attach and detach the support to and from the polyimide resin tubular product, and there is a problem that workability in manufacturing the composite tubular product is significantly reduced. As a method for solving this, a method has been proposed in which at least one of the inner peripheral surface of the tubular body made of a polyimide resin and the outer peripheral surface of the support is provided with irregularities to reduce the friction coefficient. This method can be improved to some extent, but the length of the polyimide resin tubular product in the longitudinal direction is a certain length or more (1
50 mm), the effect is lost, so
It is not a method applicable to actual manufacturing.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a composite tubular article which is excellent in workability and can form a fluororesin tubular outer layer having a uniform thickness. To do.

[0005]

In order to achieve the above object, the present invention provides a step of preparing a polyimide resin tubular product and a support having an outer diameter smaller than the inner diameter of the polyimide resin tubular product. Step, a step of inserting the support into the polyimide resin tubular article, and the polyimide resin tubular article by expanding the diameter of the support to adhere to the inner peripheral surface of the polyimide resin tubular article A step of supporting from the inner peripheral surface side, a step of forming a fluororesin tubular outer layer on the outer peripheral surface of the polyimide resin tubular article in the supported state, and the polyimide resin tubular article having a reduced diameter of the support. The first gist is a method for producing a composite tubular article characterized by comprising a step of taking out the support from the inside of the polyimide resin tubular article, and a step of preparing a polyimide resin tubular article, A step of preparing a cylindrical support having an outer diameter smaller than the inner diameter and having a plurality of through holes on the outer peripheral surface, and the step of inserting the support into the polyimide resin tubular article, A fluid is introduced into the inside of the support and discharged from the through hole to the outside, and a step of supporting the polyimide resin tubular product from the inner peripheral surface side by the discharge pressure of the fluid, and the polyimide resin made in the supported state. A second method for producing a composite tubular article, comprising a step of forming a fluororesin tubular outer layer on the outer peripheral surface of the tubular article, and a step of taking out the support from the inside of the polyimide resin tubular article. Use as a summary.

[0006]

According to the first production method of the present invention, since the support having the outer diameter smaller than the inner diameter of the polyimide resin tubular product is used, the insertion and removal can be easily performed inside the polyimide resin tubular product. it can. Moreover, since the diameter of this support is increased, it can be supported in a completely intimate contact with the inner peripheral surface of the tubular article. Therefore, by forming the fluororesin tubular outer layer in this supported state, it is possible to form the outer layer having a uniform thickness. Further, according to the second manufacturing method of the present invention, similarly to the first manufacturing method, since a support having an outer diameter smaller than the inner diameter of the polyimide resin tubular object is used, insertion into and removal from the tubular object is performed. Can be done easily. Further, it is possible to discharge the fluid from the plurality of through holes on the outer peripheral surface of the support body and to support the tubular object from the inner peripheral surface side by the discharge pressure of the fluid without causing distortion. Therefore, by forming the fluororesin tubular outer layer in this supported state, it is possible to form the outer layer having a uniform thickness.

Next, the present invention will be described in detail.

According to the first production method of the present invention, a composite tubular article comprising a polyimide resin tubular inner layer and a fluororesin tubular outer layer is obtained as follows.

First, a polyimide resin tubular article is prepared. The polyimide resin tubular material is not particularly limited, but it is preferable to use a seamless type. This seamless type polyimide resin tubular article can be obtained by a conventionally known method, and can be produced, for example, by the above-mentioned method (JP-A-3-130149). Specifically, it can be obtained by applying a polyamic acid solution that is a precursor of a polyimide resin to the inner peripheral surface of a cylindrical cylinder made of a heat-resistant material such as glass or metal, and then converting this polyamic acid into an imide. it can.

The polyamic acid solution can be obtained by reacting tetracarboxylic acid dianhydride or its derivative with approximately equimolar amounts of diamine in an organic polar solvent.

The above tetracarboxylic acid dianhydride is
Examples include those represented by the following general formula.

[Chemical 1]

Such tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3 ', 4,4'-
Benzophenone tetracarboxylic dianhydride, 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride, 2,
3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1, 4,5,8-Naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, perylene -3, 4, 9,
Examples thereof include 10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, and ethylenetetracarboxylic dianhydride.

Also, The above diamine includes 4,4′-
Diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-
Dichlorobenzidine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone,
1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl-
4,4'-diaminobiphenyl, benzidine, 3,3 '
-Dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminophenyl sulfone, 4,4'-
Diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene, bis (p-β-amino-t-butylphenyl) ether, bis (p-β- Methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-
5-aminopentyl) benzene, 1-isopropyl-
2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, Diaminopropyltetramethylenediamine, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine,
2,11-diaminododecane, 1,2-bis- (3-aminopropoxy) ethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,
5-dimethylhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,17
-Diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane ,
Piperazine, H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (C
H ₂ ) NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH
_{2, H 2 N (CH 2} ) 3 N (CH 3) (CH 2) 3 NH
₂ etc.

The organic polar solvent used in the preparation of the polyamic acid solution is N, N-dimethylformamide, N, N-dimethylacetamide or the like.
N-dialkylamides can be mentioned. These can be easily removed from the polyamic acid solution by evaporation, substitution, diffusion or the like. In addition, polar solvents other than the above, such as N, N-diethylformamide, N, N-
Diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine, dimethylsulfone, tetramethylenesulfone, dimethyltetramethylenesulfone and the like can be used,
These organic polar solvents may be used alone or in combination of two or more. Further, these organic polar solvents may be mixed with at least one kind of phenols such as cresol, phenol, xylenol, benzonitrile, dioxane, hexane, benzene, and toluene. The addition of water may reduce the molecular weight of the resulting polyamic acid due to hydrolysis,
Not preferable.

Monomer concentration when the above tetracarboxylic dianhydride (a) and diamine (b) are reacted in an organic polar solvent [(a) + (b) concentration in the above solvent]
Is set according to various conditions and is usually 5 to 30% by weight.
Is. The reaction temperature is preferably set to 80 ° C or lower, more preferably 5 to 50 ° C.
And, the reaction time is preferably in the range of about 0.5 to 10 hours.

Thus, by reacting the tetracarboxylic dianhydride and the diamine in the organic polar solvent, a polyamic acid is produced, and the solution viscosity of the polyamic acid increases with the progress of the reaction. When this solution viscosity is expressed as logarithmic viscosity [η], it is preferable to use a polyamic acid of 0.5 or more. That is, the polyimide resin tubular product formed by using a polyamic acid having a logarithmic viscosity [η] of 0.5 or more has an advantage of excellent heat resistance. The logarithmic viscosity [η] is calculated by the following formula by measuring the drop times of the polyamic acid solution and the organic polar solvent using a capillary viscometer.

[0017]

[Equation 1]

Next, the above-mentioned polyamic acid solution is uniformly applied to the inner peripheral surface of the cylinder by running a bullet-shaped body or a spherical body in the cylindrical cylinder. At this time, the viscosity of the polyamic acid solution is preferably about 10 to 10000 poise (measured value with a B-type viscometer at the temperature during the coating operation) from the viewpoint of workability. Further, the cylinder is used, the inner diameter of which is substantially equal to the outer diameter of the intended polyimide resin tubular product, and in order to improve the appearance of the resulting composite tubular product, the inner peripheral surface of the cylinder is roughened. It is preferable that the roughness (Rz) is about 1 to 10 μm.

Thus, after coating the inner surface of the heat-resistant cylinder with the polyamic acid solution, the polyamic acid is heated to convert the polyamic acid into an imide, and the solvent and ring-closing water are removed by evaporation to produce a polyimide resin tubular product. You can

Although the above method uses a polyamic acid, it is also possible to use an organic solvent-soluble polyimide resin. In this case, the target polyimide resin tubular product can be obtained by the same operation as above except that the imide conversion is not performed.

Next, the desired composite tubular product can be obtained by forming a fluororesin tubular outer layer on the outer peripheral surface of the obtained polyimide resin tubular product. When forming this fluororesin tubular outer layer, it is necessary to support the polyimide resin tubular material with a support, and there are two types of methods for supporting this.

First, the first method is to use a support body having an outer diameter smaller than the inner diameter of the above-mentioned polyimide resin tubular material and covering the outer peripheral surface of the shaft body with an elastic sleeve provided with a gap. Is the method to use. This shaft is made of metal,
A ceramic or plastic shaft can be used, and it is preferable to use a shaft made of a hard material that is not deformed by centrifugal force during rotation. Further, as the elastic sleeve, it is preferable to use a sleeve whose elastic body is made of rubber such as silicone rubber, fluororubber and urethane rubber. Then, the composite tubular article is manufactured as follows using the above-mentioned support. That is,
First, as shown in FIG. 1 (a), a support made up of a shaft body 13 and an elastic sleeve 12 is attached to a tubular body 1 made of a polyimide resin.
1 inside, the fluid is introduced between the shaft body 13 and the elastic sleeve 12 to expand the diameter of the sleeve 12 as shown in FIG. Support it in close contact with the surface. Then, after forming the fluororesin tubular outer layer in this supporting state, the fluid between the shaft body 13 and the elastic sleeve 12 is discharged to reduce the diameter of the sleeve 12 and remove it from the tubular article 11. The desired composite tubular product can be obtained by a series of steps. As the above-mentioned fluid, it is usually preferable to use air, but not limited to this, it is also possible to use gas such as nitrogen gas or liquid such as water. Further, the fluororesin tubular outer layer, the polyimide resin tubular article supported from the inner peripheral surface side by the expanded support is simultaneously rotated in the circumferential direction together with the support, to give a fluororesin solution or a fluororesin dispersion. It can be formed by spray coating the outer peripheral surface of the tubular article.

The fluororesin used for forming the fluororesin tubular outer layer is not particularly limited.
Polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (F
EP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE) and the like can be used.

The outer peripheral surface of the polyimide resin tubular material is spray-coated with a fluororesin solution or the like, and then heated to evaporate and remove the solvent of the solution or the like, and the fluororesin is sintered to remove the polyimide resin. A composite tubular product comprising a tubular inner layer and a fluororesin tubular outer layer can be obtained.

The spray coating of the fluororesin solution or the like is carried out by simultaneously rotating the support and the polyimide resin tubular product in the circumferential direction, or by fixing the support and the polyimide resin tubular product and spraying the nozzle. It is also possible to carry out spray coating by a method of rotating. Furthermore, the method of applying the fluororesin solution or the like to the outer peripheral surface of the polyimide resin tubular material is not limited to the above spray coating method, but may be an immersion method or the like.

The second method for supporting the polyimide resin tubular article has an outer diameter smaller than the inner diameter of the polyimide resin tubular article and is divided into a plurality of pieces in the outer peripheral direction along the central axis. This is a method of using a substantially rod-shaped support body composed of a support portion. This support is a substantially rod-shaped body made of metal, ceramic, or plastic, and each support portion of the support is expanded and contracted by a mechanical method, a method of introducing a fluid, a method of rotating centrifugal force, or the like. Diameter is possible. That is, as shown in FIG. 2 (a), a support body composed of each support portion 15 is inserted into the inside of the tubular article 11, and each support portion 15 is placed at the center of the shaft body as shown in FIG. 2 (b). The support is expanded by moving outward about the shaft, and the support is closely attached to and supported on the inner peripheral surface of the tubular article 11, and after forming the fluororesin tubular outer layer in this supported state, By moving the support portion 15 inwardly around the central axis of the shaft body, the diameter-expanded support body is reduced in diameter and taken out from the inside of the tubular article 11, whereby a target composite tubular article is obtained. Obtainable. In addition,
As the method for forming the fluororesin tubular outer layer and the fluororesin used therefor, the same resin as in the first method can be used, and the fluororesin tubular outer layer is formed by the same method.

Next, a method for producing a composite tubular article by the second production method other than the method using the above two types of shafts will be described.

That is, first, a polyimide resin tubular article is produced by the same method as the first production method. On the other hand, a cylindrical support having an outer diameter smaller than the inner diameter of the polyimide resin tubular article and having a plurality of through holes uniformly distributed on the outer peripheral surface is prepared. This support is made of metal,
It is preferably made of a hard material such as ceramic or plastic that is not deformed by centrifugal force during rotation. Then, as shown in FIG. 3A, a support 17 having a plurality of through holes 16 on the outer peripheral surface is inserted into the tubular object 11. Then, as shown in FIG. 3 (b), the fluid is introduced into the inside of the support body 17 and discharged from the through hole 16 in the direction of the arrow, and the tubular article 11 is supported from the inside by the discharge pressure of this fluid. In this supporting state, after forming the fluororesin tubular outer layer in the same manner as in the first method, the introduction of the fluid is stopped, and the support 17 is taken out from the inside of the tubular object 11 to obtain the object. Composite tubing can be manufactured. The fluid may be gas or liquid, but it is preferable to use air from the viewpoint of workability. In addition, the support 1
When 7 is taken out from the tubular article 11, it is possible to lower the discharge pressure of the fluid from the through hole and take it out in addition to stopping the introduction of the fluid.

[0029]

As described above, according to the first method for producing the composite tubular article of the present invention, a support having an outer diameter smaller than the inner diameter of the polyimide resin tubular article is inserted into the tubular article, and The body is expanded to support the inner peripheral surface of the tubular object in close contact with it, to form a fluororesin tubular outer layer in this state, and then the expanded support is reduced in diameter from the outer layer of the tubular object. It is equipped with a process of taking it out. Further, the second manufacturing method is a cylindrical support having an outer diameter smaller than the inner diameter of the polyimide resin tubular article, and having a plurality of through holes on the outer peripheral surface of the polyimide resin tubular article. , The fluid is introduced into the inside of the support and discharged to the outside through the through hole, and the polyimide resin tubular product is supported from the inner peripheral surface side by the discharge pressure of the fluid, and the polyimide resin is in this supported state. The method further comprises a step of forming a fluororesin tubular outer layer on the outer peripheral surface of the tubular product and then taking out the support from the inside of the polyimide resin tubular product. Therefore, in the present invention, the support can be easily inserted into and removed from the tubular article, so that the workability is excellent and the manufacturing efficiency is improved.
Further, in the first manufacturing method, the support state, the support and the polyimide resin tubular material are completely in contact with each other, and in the second manufacturing method, due to the fluid discharge pressure, the polyimide resin tubular material is Since it is supported from the inside, when forming the fluororesin tubular outer layer, the polyimide resin tubular article is not distorted, and a composite tubular article having a fluororesin tubular outer layer having a uniform thickness can be produced. Like As a result, an image obtained by using this composite tubular material as a fixing belt does not cause shading, and a high quality image can be obtained.

Next, examples will be described together with comparative examples.

Prior to the Examples and Comparative Examples, a tubular product made of a polyimide resin and a fluororesin dispersion were prepared by the following methods.

That is, first, as the tetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride was prepared, and as the diamine, p-phenylenediamine was added to the tetracarboxylic dianhydride. Prepared so as to be equimolar, dissolved in N-methyl-2-pyrrolidone in a flask (monomer concentration: 20% by weight), and stirred in a nitrogen gas atmosphere at a temperature of 20 ° C. for 5 hours. While reacting, a polyamic acid was synthesized. The rotational viscosity of this polyamic acid (measurement temperature: 20 ° C.) was 34.
The viscosity was 000 poise and the logarithmic viscosity [η] (measurement temperature: 30 ° C) was 2.9. Then, add 50 parts of this polyamic acid solution.
The mixture was heated to ° C and adjusted to a rotational viscosity of 1500 poise. Then, a stainless steel cylinder (cylindrical shape) having an inner diameter of 50 mm, a wall thickness of 5 mm and a length of 500 mm was immersed in the polyamic acid solution and then pulled up, and then the cylinder was held vertically, and the outer diameter of which was 49.4 mm. The polyamic acid solution was applied in a uniform thickness to the inside of the cylinder by moving the bullet-shaped traveling body downward by its own weight. This is 70
After heating at 60 ° C. for 60 minutes, the temperature was further raised to 300 ° C. and heating for 60 minutes to remove the solvent and the ring-closing water and at the same time perform imide conversion to form a polyimide resin tubular product. This polyimide resin tubular product was taken out of the cylinder, and the length was 450 mm, the outer diameter was 50 mm, and the thickness was 30 μm.
Molded into.

On the other hand, by mixing an aqueous dispersion having a PFA concentration of 60% by weight (TE-334J manufactured by DuPont) and an aqueous dispersion having a carbon black concentration of 16.5% (W-311N manufactured by Lion), P
A mixed dispersion of FA and carbon black was obtained. In addition, PFA in this fluororesin dispersion
The mixing ratio of carbon black was 4 parts by weight with respect to 100 parts by weight of PFA.

[0034]

Example 1 Into the polyimide resin tubular article produced above, a support body was inserted, as shown in FIG. 1, in which an iron shaft body 13 having an outer diameter of 48 mm and a silicone rubber sleeve 12 provided with a gap therebetween was coated. . Then, air (air pressure: 3.5 kg / cm ² ) is introduced between the iron shaft body 13 and the silicone rubber sleeve 12 to introduce the sleeve 12 into the sleeve 12.
Was expanded and completely adhered to and supported by the inner peripheral surface of the tubular article 11. Then, the support and the tubular article are rotated in the circumferential direction at 1000 rpm, and the fluororesin dispersion prepared above is sprayed onto the outer circumferential surface of the tubular article using an air spray gun (W-71, manufactured by Iwata Co., Ltd.). Coated. After that, the introduction of air was stopped to reduce the diameter of the sleeve, and the support was taken out from the inside of the tubular object. Then, the spray-coated tubular product was air-dried for 10 minutes, heated at 100 ° C. for 10 minutes, and further heated at 400 ° C. for 10 minutes to be sintered to obtain a target composite tubular product. Incidentally, the work of inserting and removing the support into and from the polyimide resin tubular product can be easily performed, and also in the spray coating work of the fluororesin dispersion, distortion due to the spray pressure of the tubular product, etc. Did not happen.

The thickness of the fluororesin tubular outer layer of the obtained composite tubular product was 8.5 μm on average, and the variation was 0.3 μm.
It was m or less. Furthermore, when a fluorescent lamp was put inside the composite tubular product and the transmitted light thereof was visually observed for the uniformity of the thickness of the fluororesin tubular outer layer, no shade due to the variation in thickness was observed. Also, the surface roughness Rz
Was 3.2 μm and the surface resistance was 4 × 10 ⁵ Ω / □.
Then, when this composite tubular product was molded into a width of 300 mm and used as a fixing belt of an image fixing device, the obtained image was uniform and the offset property was also good.

[0036]

Example 2 A support having an outer diameter of 48.5 mm composed of four stainless steel rods 15 as shown in FIG. 2 was inserted into the inside of the polyimide resin tubular article prepared above, and then each of the rods 15 was attached. The diameter was mechanically increased, and the inner peripheral surface of the tubular article 11 was closely contacted and supported. Then, in the supported state, the support and the tubular object are rotated in the circumferential direction at 1000 rpm,
The fluororesin dispersion was spray-coated in the same manner as in Example 1. Then, the diameter of each rod 15 was reduced, and the support was taken out from the inside of the tubular article 11. And the above-mentioned tubular article 1 which has been spray-coated.
After air-drying 1 for 10 minutes, heat at 100 ° C for 10 minutes,
Further, it was heated at 400 ° C. for 10 minutes and sintered to obtain a target composite tubular product. Incidentally, the work of inserting and removing the support into and from the polyimide resin tubular product can be easily performed, and also in the spray coating work of the fluororesin dispersion, distortion due to the spray pressure of the tubular product, etc. Did not happen.

The fluororesin tubular outer layer of the obtained composite tubular article had an average thickness of 7.8 μm and a variation of 0.5 μm.
It was m or less. Furthermore, when a fluorescent lamp was put inside the composite tubular product and the uniformity of the thickness of the fluororesin tubular outer layer was visually observed by transmitted light, no shade due to the variation in thickness was observed. The surface roughness Rz is 3.
The surface resistance was 4 μm and the surface resistance was 6 × 10 ⁵ Ω / □. Then, when this composite tubular product was molded into a width of 300 mm and used as a fixing belt of an image fixing device, the obtained image was uniform and the offset property was also good.

[0038]

Example 3 A cylindrical support 17 made of stainless steel having an outer diameter of 49 mm and through holes 16 uniformly distributed on the outer peripheral surface as shown in FIG. Then, air (air pressure: 2.5 kg / cm ² ) was introduced into the inside of the support 17 to discharge the air from the through hole 16, and the tubular article 11 was supported by this air discharge pressure. Support 1 in this support state
7 and the tubular article 11 were simultaneously rotated in the circumferential direction at 1000 rpm, and the fluororesin dispersion was spray-coated in the same manner as in Example 1. Then, the introduction of air was stopped and the support 17 was taken out from the inside of the tubular article 11. Then, the spray-coated tubular product 11 was air-dried for 10 minutes, heated at 100 ° C. for 10 minutes, and further heated at 400 ° C. for 10 minutes to sinter to obtain a target composite tubular product. Incidentally, the work of inserting and removing the support into and from the polyimide resin tubular product can be easily performed, and also in the spray coating work of the fluororesin dispersion, distortion due to the spray pressure of the tubular product, etc. Did not happen.

The thickness of the fluororesin tubular outer layer of the obtained composite tubular product was 8.1 μm on average, and the variation was 0.4 μm.
It was m or less. Furthermore, when a fluorescent lamp was put inside the composite tubular product and the uniformity of the thickness of the fluororesin tubular outer layer was visually observed by transmitted light, no shade due to the variation in thickness was observed. The surface roughness Rz is 2.
The surface resistance was 9 μm and the surface resistance was 3 × 10 ⁵ Ω / □. Then, when this composite tubular product was molded into a width of 300 mm and used as a fixing belt of an image fixing device, the obtained image was uniform and the offset property was also good.

[0040]

[Comparative Example] A cylindrical stainless steel support having an outer diameter of 49 mm was inserted into the polyimide resin tubular article prepared above, and the above-mentioned support and tubular article were attached to each other at both ends using adhesive tapes. Was fixed and integrated. Example 1 was rotated in the circumferential direction at 1000 rpm
The fluororesin dispersion was spray-coated in the same manner as in. Then, the adhesive tape was peeled off and the support was taken out from the inside of the tubular article. Then, the spray-coated tubular product was air-dried for 10 minutes, heated at 100 ° C. for 10 minutes, and further heated at 400 ° C. for 10 minutes.
It was heated for a minute and sintered to obtain a target composite tubular product. In addition, since the support was not supported in a state where the support was in complete contact with the inner peripheral surface of the tubular article, distortion was caused by the spray pressure of the tubular article during the coating operation of the fluororesin dispersion.

The thickness of the fluororesin tubular outer layer of the obtained composite tubular article was 7.7 μm on average, and the variation was 3.2 μm.
It was m. Furthermore, when a fluorescent lamp was placed inside the composite tubular article and the uniformity of the thickness of the fluororesin tubular outer layer was visually observed by transmitted light, the lightness and darkness due to the variation in the thickness was clearly confirmed. When this tubular product was molded into a width of 300 mm and used as a fixing belt of an image fixing device, in the obtained image, shading due to uneven thickness of the fluororesin tubular outer layer was observed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram when a tubular body made of a polyimide resin is supported by a support in one embodiment of the present invention.

FIG. 2 is an explanatory diagram when a tubular body made of a polyimide resin is supported by a support in one embodiment of the present invention.

FIG. 3 is an explanatory diagram when a tubular body made of a polyimide resin is supported by a support in one embodiment of the present invention.

FIG. 4 is an explanatory diagram of a heat roller fixing method.

FIG. 5 is an explanatory diagram of a fixing method using a fixing belt.

[Explanation of symbols]

 11 Polyimide resin tubular object 12 Elastic sleeve 13 Shaft body

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical indication location B29L 9:00 4F 29:00 4F (72) Inventor Masao Nakamura 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Tokio Fujita 1-2-1 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (4)

[Claims] 1. A step of preparing a tubular body made of polyimide resin, a step of preparing a support having an outer diameter smaller than the inner diameter of the tubular body made of polyimide resin, and the supporting body being made of the tubular body made of polyimide resin. The step of inserting into the inside, the step of supporting the polyimide resin tubular article from the inner circumferential surface side by closely contacting the inner diameter of the polyimide resin tubular article with the diameter of the support, and supporting the above. A step of forming a fluororesin tubular outer layer on the outer peripheral surface of the polyimide resin tubular article in a state, and a step of reducing the diameter of the support to take out the support from the inside of the polyimide resin tubular article A method for producing a composite tubular product characterized by: 2. An elastic sleeve is provided on the outer peripheral surface of a shaft body by providing a gap between the elastic body sleeve and the elastic body sleeve, and a fluid is introduced between the shaft body and the elastic body sleeve. 2. The method for producing a composite tubular article according to claim 1, wherein the diameter of the elastic sleeve is reduced by expanding the diameter and discharging fluid from between the elastic sleeve and the shaft of the expanded support. 3. A substantially rod-shaped support body composed of a plurality of support portions divided in an outer peripheral direction along a central axis is used, and each of the support portions moves outwardly about the central axis of the support body. 2. The composite according to claim 1, wherein the support is expanded in diameter by means of which each support portion of the expanded support is moved inward about the central axis of the support to reduce the diameter of the support. How to make tubular products. 4. A process for preparing a tubular body made of a polyimide resin, and a cylindrical support having an outer diameter smaller than the inner diameter of the tubular body made of the polyimide resin and having a plurality of through holes on an outer peripheral surface thereof. And the step of inserting the support into the polyimide resin tubular article, and introducing the fluid into the support to discharge it from the through hole to the outside, and the polyimide resin at the discharge pressure of the fluid. A step of supporting the tubular product made from the inner peripheral surface side, a step of forming a fluororesin tubular outer layer on the outer peripheral surface of the polyimide resin tubular product in the supported state, and from the inside of the polyimide resin tubular product A process for producing a composite tubular article, comprising the step of taking out a support.