JP2003200443A - Method for manufacturing heat-resistant resin tubular article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a heat-resistant resin tubular article prevented from getting out of shape by heating and drying and excellent in releasability after molding. <P>SOLUTION: In the method for manufacturing the heat resistant resin tubular article including a process for applying a heat-resistant resin material solution to the surface of a cylindrical mold and solidifying the formed layer by heating and drying until bringing the same to a self-supporting state and peeling the solidified tubular article from the surface of the mold and a process for baking the tubular article in such a state that a support having an outer diameter smaller than the inner diameter of the tubular article is inserted in the tubular article, the support is hollow and hermetically closed at its upper end and has fine holes provided to the side surface thereof. After the completion of the baking process, air is fed into the hollow part of the support under pressure and air is injected in the gap between the outside of the support and the heat- resistant resin tubular article from the fine holes of the side surface of the support to peel the heat-resistant resin tubular article from the support. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a heat-resistant resin tubular product. The heat-resistant resin tubular material is used, for example, as a fixing / conveying belt and a transfer / fixing belt used in image forming apparatuses such as electrophotographic copying machines, printers, and facsimiles.

[0002]

2. Description of the Related Art Conventionally, rolls and drums have been used as rotating members for electrophotographic image forming apparatuses.
In recent years, plastic belts have been put into practical use in place of these members in order to solve downsizing of the apparatus. A heat resistant resin is used for a plastic belt used for such an application. For example, as the heat-resistant resin, one using a thermoplastic resin such as polycarbonate or ethylene tetrafluoroethylene copolymer (JP-A-10-10880, JP-A-2000-25097, etc.) or a thermosetting resin may be used. Those using a certain heat resistant resin have been proposed. Among these heat resistant resins, a seamless belt using a polyimide resin is excellent in heat resistance and durability.

In these seamless belt manufacturing methods,
A method in which a heat-resistant resin material solution is applied to the outer surface of a cylindrical mold, and then a hollow ring is passed to finish it to a predetermined thickness, followed by baking by heating and drying, or a hollow mold. After applying a heat-resistant resin material solution to a predetermined thickness on the inner surface of the above, a step of obtaining a solidified belt obtained by solidifying the heat-resistant resin material by a method of baking into a film by heating and drying is provided.

Focusing on the method of peeling the film from the mold in the above step, (1) a method of peeling the tubular material from the mold during solidification and transferring it to a support to complete film formation is adopted. (JP-A-60-1664)
24, JP-A-7-156287, JP-A-20
No. 00-271946). In this method, since the linear thermal expansion coefficient of the tubular material is smaller than that of the support, it can be easily taken out from the support after the support contracts.

In addition to the above (1), (2) a heat-resistant resin tubular product is molded on the inner surface of the hollow mold, heated and dried to form a film, and then peeled from the hollow mold. Methods and the like.

[0006]

However, the method (1) has a problem that the heat-resistant resin tubular product obtained is limited to a specific resin. Further, if the coefficient of linear thermal expansion of the heat-resistant resin tubular product is larger than that of the support, there is a problem in that it adheres to the support and does not come off from the support. Further, in the method (2), when the heat-resistant resin tubular product is fired in the hollow mold, there is a problem that the heat-resistant resin tubular product is peeled off during firing due to volume contraction during solidification. Alternatively, there is a problem that the hollow mold does not come into close contact with the inside of the mold so that it cannot be peeled off.

[0007] Therefore, an object of the present invention is to provide a method for producing a heat-resistant resin tubular product which is prevented from losing its shape due to heating and drying and which is excellent in peelability after molding.

[0008]

As a result of intensive studies to solve the above problems, the present inventor has found that the above object can be achieved by the method described below, and has completed the present invention.

That is, in the method for producing a heat-resistant resin tubular product of the present invention, the heat-resistant resin material solution is applied to the surface of a cylindrical mold, solidified by heating and drying until self-supporting, and then the solidified tubular product. A step of peeling from the mold surface,
In the method for producing a heat-resistant resin tubular product, which comprises a step of firing a support having an outer diameter smaller than the inner diameter of the tubular product in the tubular product, the support is hollow and its upper end is closed. , Which has pores on the side surface thereof, and after the firing step is completed, gas is pressure-fed to the hollow portion of the support, and gas is introduced between the outside of the support and the heat-resistant resin tubular material through the pores on the side surface. By further injecting the heat-resistant resin tubular material from the support.

The linear thermal expansion coefficient of the heat-resistant resin tubular product is
It is preferably larger than the linear thermal expansion coefficient of the support.

[Operation and Effect] According to the method for producing a heat-resistant resin tubular product of the present invention, the inner diameter of the tubular product is changed by the gas fed under pressure from the state of close contact between the support and the heat-resistant resin tubular product at the end of the firing step. It is expanded to a non-contact state, and a clearance is generated between the support and the tubular object. By doing so, the method of the present invention has an effect of easily peeling the formed tubular article in a short time. Further, according to the method for producing a heat-resistant resin tubular product of the present invention, even if the linear thermal expansion coefficient of the heat-resistant resin tubular product is larger than the linear thermal expansion coefficient of the support, gas from the hollow portion of the support The peeling step of feeding under pressure has the effect of easily peeling the molded tubular product in a short time. Therefore, the tubular article can be efficiently produced without being limited by the linear thermal expansion coefficient of the heat-resistant resin tubular article.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-resistant resin used in the method for producing a heat-resistant resin tubular product of the present invention is not particularly limited as long as it is a resin that can be molded into a film.

As the heat-resistant resin material solution used in the method for producing a heat-resistant resin tubular product of the present invention, various solutions can be used. For example, in the case of a tubular product made of a thermoplastic resin such as polycarbonate, polyamide, polyetherketone, or polyethersulfone, an organic solvent solution of the thermoplastic resin is used as the heat-resistant resin material solution. In the case of a tubular product made of a copolymer, its dispersion is used as a heat resistant resin material solution. On the other hand, in the case of a tubular product made of a polyimide resin, a polyamic acid solution which is a polyimide precursor solution is used as the heat resistant resin material solution. Polyimide resin is excellent in heat resistance and durability among heat resistant resins that form tubular products. The polyamic acid solution, which is a polyimide resin precursor solution, will be described below.

The polyamic acid solution is obtained by reacting an acid dianhydride component and a diamine component in a solvent.
Specific examples of the acid dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. Anhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride Anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride,
Bis (3,4-dicarboxyphenyl) sulfone dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylene tetracarboxylic acid Examples thereof include acid dianhydride.

Further, it is reacted with such an acid dianhydride.
Specific examples of the diamine include 4,4'-diaminodiphene.
Nyl ether, 3,3'-diaminodiphenylmethane,
4,4'-diaminodiphenylmethane, 3,3'-diglycan
Lolobenzidine, 4,4'-diaminodiphenylsulfate
, 3,3'-diaminodiphenyl sulfone, 1,5
-Diaminonaphthalene, m-phenylenediamine, p-
Phenylenediamine, 3,3'-dimethyl-4,4'-
Biphenyldiamine, benzidine, 3,3'-dimethyl
Benzidine, 3,3'-dimethoxybenzidine, 4,
4'-diaminophenyl sulfone, 4,4'-diamino
Diphenyl sulfide, 4,4'-diaminodiphenyl
Propane, 2,4-bis (β-amino-tert-butyl) to
Ruene, bis (p-β-amino-tert-butylphenyl)
Ether, bis (p-β-methyl-δ-aminopheni
) Benzene, bis-p- (1,1-dimethyl-5-a
Minopentyl) benzene, 1-isopropyl-2,4-
m-phenylenediamine, m-xylylenediamine, p
-Xylylenediamine, di (p-aminocyclohexyl)
) Methane, hexamethylenediamine, heptamethylene
Diamine, octamethylenediamine, nonamethylenedia
Min, decamethylenediamine, diaminopropyl tetra
Methylene, 3-methylheptamethylenediamine, 4,4
-Dimethylheptamethylenediamine, 2,11-diami
Nododecane, 1,2-bis- (3-aminopropoxy)
Ethane, 2,2-dimethylpropylenediamine, 3-me
Toxyhexamethylenediamine, 2,5-dimethylhex
Samethylenediamine, 2,5-dimethylpentamethylene
Diamine, 3-methylpentamethylenediamine, 5-me
Cirnonamethylenediamine, 2,17-diaminoeico
Sadecan, 1,4-diaminocyclohexane, 1,10
-Diamino-1,10-dimethyldecane, 1,12-di
Amino octadecane, 2,2-bis [4- (4-amino
Phenoxy) phenyl] propane, piperazine, H₂ N
(CH₂ )₃ O (CH₂ )₂ OCH₂ NH₂ , H ₂ N
(CH₂ )₃ S (CH₂ )₃ NH₂ , H₂ N (CH₂ )
₃ N (CH₃ ) (CH₂ )₃ NH₂ Etc.

The linear thermal expansion coefficient of the polyimide resin is changed by appropriately selecting and blending the acid dianhydride and diamine. The acid dianhydride and diamine may be used alone or in combination of two or more.

As a solvent for polymerizing the acid dianhydride component and the diamine component, an appropriate solvent can be used, but an organic polar solvent is preferably used in view of solubility and the like, and N, N-dialkylamide is used. Classes are preferred. Specifically, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-
Diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine, dimethylsulfoxide, tetramethylenesulfone,
Examples thereof include dimethyltetramethylene sulfone. These can be used alone or in combination. Further, cresol, phenol, phenols such as xylenol, benzonitrile, hexane, benzene, toluene and the like can be mixed alone or in combination with the organic polar solvent. However, it is preferable to avoid mixing of water in order to prevent lowering of the molecular weight due to hydrolysis of the generated polyamic acid.

A polyamic acid solution is obtained by polymerizing the acid dianhydride component and the diamine component in an organic polar solvent. The monomer concentration (acid dianhydride component and diamine component in the solvent) at that time is set according to various conditions, but is preferably 5 to 30% by weight. Further, the reaction temperature is preferably set to 80 ° C. or lower, more preferably 5 to 60 ° C. The reaction time is 0.5 to 10
Time is preferred.

Although the solution viscosity increases as the polymerization reaction progresses, it is preferable to obtain a polyamic acid having a logarithmic viscosity [η] of 0.5 or more. A polyimide resin tubular product formed by using a polyamic acid having a logarithmic viscosity [η] of 0.5 or more has an advantage of being particularly excellent in heat resistance.

The above-mentioned logarithmic viscosity is a value calculated by the following formula by measuring the drop time of the polyamic acid solution and the solvent using a capillary viscometer.

[0021]

## EQU1 ## [η] = (ln (t ₁ / t ₀ )) / c (where, t ₀ is the dropping time of the solvent, t ₁ is the dropping time of the solution, and c is the concentration of the polyamic acid in the solution ( g / d
l)).

The heat-resistant resin material solution (particularly polyamic acid solution) in the present invention has various purposes such as thermal conductivity, conductivity, antistatic property, semiconductivity, high slidability, high strength and high elasticity. A filler may be added as appropriate depending on the application. For example, heat conductive inorganic powders such as aluminum nitride, boron nitride, alumina, silicon carbide, silicon nitride, and silica, conductive or semiconductive powders such as carbon black, aluminum, nickel, tin oxide, potassium titanate, and poly, Examples thereof include tetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) fluororesin.
The filling amount of the filler can be determined according to the purpose within the scope of the present invention.

The method for producing the heat-resistant resin tubular product of the present invention is as follows:
The method includes the steps of applying the heat-resistant resin material solution to the surface of a cylindrical mold, solidifying the solution by heating and drying until self-supporting, and then peeling the solidified tubular product from the surface of the mold.

The cylindrical mold may be any as long as it has been conventionally used for producing a seamless belt or the like, and a cylindrical mold having an outer surface on which a tubular material is formed, an inner surface Any of the hollow-structured cylindrical molds having a tubular object forming surface can be used. Usually, the heat-resistant resin material solution is applied to the inner surface of a cylindrical metal mold according to the shape of the tubular material.

As the material of the mold, it is preferable to use metal, glass, ceramic or the like having excellent strength and heat resistance. The cylindrical outer diameter or hollow inner diameter of the mold can be arbitrarily selected according to the inner diameter or outer diameter of the tubular product to be molded.

The mold surface is not particularly limited, but it is preferable to subject the surface on which the heat-resistant resin material solution is applied to a release treatment such as silicone treatment or fluorine treatment in advance.

Next, a solution of a heat-resistant resin material such as a polyamic acid solution is applied to the surface of the cylindrical mold that has been arbitrarily released.

As a method for uniformly applying the heat-resistant resin material solution to the cylindrical mold, a known method can be applied.
For example, a method of applying with a dispenser, a method of using a scraper, a method of using a bullet-shaped running body and the like can be mentioned.

The heating temperature is not particularly limited as long as it can evaporate the solvent used in the heat-resistant resin material solution and enables the solidified tubular material to support itself, and it depends on the heat-resistant resin material solution. Can be set appropriately. When a polyamic acid solution is used as the heat-resistant resin material solution, it is preferably 230 ° C or lower in order to prevent the generation of minute voids due to rapid evaporation of the solvent, and 80 ° C or higher from the viewpoint of shortening the heating time. Is preferred. The heating time is appropriately set according to the heating temperature, and is usually about 10 to 60 minutes.

The method for peeling the solidified tubular product from the cylindrical mold is not particularly limited. The mold can be easily peeled off by releasing the mold and taking out the tubular material before firing.

The thickness of the solidified tubular product which has been peeled off is appropriately set depending on the type and application of the resin, but when a polyamic acid solution is used, it is preferably within the range of 10 to 150 μm.

Further, the method for producing a heat-resistant resin tubular product of the present invention includes a step of baking a support having an outer diameter smaller than the inner diameter of the tubular product inserted in the tubular product.

The support has an outer diameter smaller than the inner diameter of the tubular article, is hollow, has its upper end sealed, and has pores on its side surfaces. For example, a hollow rod body is exemplified. FIG. 1 shows an example of the support used in the present invention.

FIG. 1 is a side view of the support 1 having pores 2 on the side.

FIG. 2 is a sectional view showing a state in which the solidified tubular article 4 is inserted into the support 1 of FIG. A hollow portion 3 is formed inside the support 1.

The support 1 is made of a material that can withstand the firing temperature, and its linear thermal expansion coefficient may be larger or smaller than the linear thermal expansion coefficient of the heat-resistant resin tubular product under temperature conditions near the firing temperature. Often, a support made of a metal such as iron, aluminum or stainless steel, or an alloy thereof is exemplified. In the method of the present invention, since it has a peeling step described below,
The heat-resistant resin tubular material preferably has a value smaller than the linear thermal expansion coefficient.

The linear thermal expansion coefficient of the support is set according to the type of resin of the tubular product to be produced. For example, the linear thermal expansion coefficient of a tubular product made of a polyimide resin is generally 1 × 10
^{Since it is −5} to 10 × 10 ⁻⁵ cm / cm / ° C., the linear thermal expansion coefficient of the support is preferably equal to or less than the above value.

In the present invention, the coefficient of linear thermal expansion is JIS
It is a value measured according to K7197-1991.

The pores 2 on the side surface of the support body allow the pressure-fed gas to pass therethrough without causing deformation of the shape of the support body under the conditions of use of the support body to generate a clearance between the tubular object and the support body. If it is possible, the size, shape and number of the pores are not particularly limited.

The side surface of the support 1 in contact with the solidified tubular material 4 and the upper end of the support do not change their shape under the conditions of use of the support, and can withstand the pressure during gas feeding. The thickness should be as thick as possible.

The length of the support at the portion where the tubular product is inserted is preferably the same as or longer than that of the tubular product in order to maintain the shape of the tubular product during the firing process.

The solidified tubular article 4 inserted into the support 1 is
The whole support is heated and baked. In the firing step, the residual solvent and the like are removed from the solidified tubular product 4. When a polyamic acid solution is used as the heat-resistant resin material solution, the residual solvent is removed, the ring-closing water is removed, and the imide conversion reaction is completed in the firing step. The firing temperature is appropriately set depending on the components of the heat-resistant resin, but from the viewpoint of removing the residual solvent or the ring-closing water, it is preferably the heating temperature on the cylindrical mold or higher, and the solidified tubular product or the support is 430 from the viewpoint of heat resistance
C. or less is preferable. Usually, the heating time at this time is 10-6
0 minutes.

The heat-resistant resin tubular product thus obtained is taken out from the support. Therefore, in the present invention, after the firing step is completed, gas is pressure-fed to the hollow portion of the support, and the gas is injected from the pores of the side surface between the outside of the support and the heat-resistant resin tubular material. Accordingly, the method further includes a step of peeling the heat-resistant resin tubular product from the support.

The means for feeding the gas under pressure to the hollow portion of the support is not particularly limited. FIG. 3 shows an example thereof. In FIG. 3, the gas feed table 5 is attached to the bottom of the support 1. Gas is pumped from the inlet 6 and the hollow portion 3
To the outside of the support and the heat-resistant resin tubular material 7 through the pores 2.
To pass between. When the gas passes, the inner diameter of the heat-resistant resin tubular product 7 is expanded by the pressure of the gas, and a clearance is generated between the outside of the support and the heat-resistant resin tubular product 7, whereby the heat-resistant resin tubular product is removed from the support 1. Peels off.

The gas to be fed under pressure is not particularly limited, and examples thereof include air and nitrogen. The conditions for pumping are:
It is preferable that the tubular article is deformed or damaged without being deformed and is fed under pressure of 10 to 200 kPa by a compressor or the like.

The heat-resistant resin tubular product obtained by the method of the present invention is of high quality without being broken, wrinkled or scratched when peeled from the support.

The heat-resistant resin tubular product obtained by the method of the present invention is not limited to the above-mentioned single-layer structure but may have a multi-layer structure. In order to make a multilayer structure, when supporting the solidified tubular article on the support,
In order to impart further functions such as releasability, elasticity, photoconductivity, etc., fluorocarbon resin such as PTFE, FEP, PFA, silicone rubber or fluororubber etc. is applied to the outer periphery of the tubular object by spray coating, dipping or the like method. It can be further laminated to the surface.

[0048]

EXAMPLES Examples and the like specifically showing the constitution and effects of the present invention will be described below.

Example 1 Hexagonal boron nitride was mixed and stirred in 791.6 g of N-methyl-2-pyrrolidone so as to be 30 parts by weight (49.4 g) with respect to the solid content of the polyimide resin, and then 3 , 3 ', 4,4'-biphenyltetracarboxylic dianhydride 117.6 g and p-phenylenediamine 21.6 g were mixed with 4,4'-diaminodiphenyl ether 40.0 g at room temperature under nitrogen atmosphere. A polymerization reaction was carried out while stirring for a time to obtain a polyamic acid solution.

In the above, the molar ratio of p-phenylenediamine (diamine expressing rigidity) and 4,4'-diaminodiphenyl ether (diamine expressing flexibility) was 5/5.

This polyamic acid solution was applied to the inner peripheral surface of a cylindrical mold (made of stainless steel) having an inner diameter of 30 mm and a length of 500 mm, the bullet-shaped running body was processed and run by its own weight, and then rotated at 1500 rpm for 10 minutes. After making the coating film thickness uniform, it becomes 15 until the film itself can be supported.
The mixture was heated at 0 ° C. for about 60 minutes to remove the solvent and partially convert the imide. When the solidified tubular product was peeled from the mold,
The length was 450 mm, the outer diameter was 30 mm, and the thickness was 30 μm.

Then, as shown in FIG. 2, the solidified tubular article 4 is inserted into the aluminum support 1 and the solid tubular article 4 is inserted into the support 40.
By heating at 0 ° C. for 30 minutes, the removal of the solvent and the ring-closing water and the completion of the imide conversion were completed, and a tubular body made of a polyimide resin was formed on the support 1. Then, as shown in FIG. 3, the gas feed table 5 is set on the bottom of the support 1 and the pressure is reduced to 50 k.
The polyimide tubular product was peeled from the support 1 while air was being sent under a pressure of Pa.

The polyimide resin tubular product thus extracted did not suffer from appearance defects such as folds, wrinkles and scratches, and the extraction time was as short as 3 seconds per piece.

At this time, the linear thermal expansion coefficient of aluminum constituting the support 1 is 2.3 × 10 ⁻⁵ cm / cm / ° C., whereas the linear thermal expansion coefficient of the polyimide resin tubular product is 3. It was as large as 5 × 10 ⁻⁵ cm / cm / ° C. The coefficient of linear thermal expansion is in accordance with JIS K7197-1991, a thermal analyzer TMA / SS60 manufactured by Seiko Instruments Inc.
It was measured at 00.

Example 2 A polyimide resin tubular product was obtained in the same manner as in Example 1 except that a stainless steel support was used. The obtained polyimide resin tubular product,
It was peeled off in the same manner as in Example 1.

The polyimide resin tubular product extracted in this manner did not suffer from appearance defects such as folds, wrinkles and scratches, and the extraction time was very short, 3 seconds per piece.

At this time, the linear thermal expansion coefficient of the stainless steel forming the support 1 is 1.7 × 10 ⁻⁵ cm / cm / ° C., whereas the linear thermal expansion coefficient of the polyimide resin tubular product is 3. It was as large as 5 × 10 ⁻⁵ cm / cm / ° C.

(Comparative Example 1) A polyimide resin tubular article was formed in the same manner as in Example 1 except that the support was made of aluminum and the shape of the support was cylindrical and did not have a hollow portion and gas was not fed under pressure. did. After cooling to room temperature, the formed polyimide resin tubular product was tried to be extracted, but it took a very strong force to extract the polyimide resin tubular product in close contact with the support, and the extraction time was 10 seconds per one, and workability was improved. It was very bad. In addition, the polyimide resin tubular product thus extracted had breakage, wrinkles, scratches, and other defective appearance.

At this time, the cotton expansion coefficient of aluminum constituting the support is 2.3 × 10 ⁻⁵ cm / cm / ° C., while the cotton expansion coefficient of the polyimide resin tubular product is 3.5.
It was as large as × 10 ^-5 cm / cm / ° C.

(Comparative Example 2) A polyimide resin tubular article was formed in the same manner as in Example 1 except that the material of the support was stainless steel, and the shape was a cylindrical shape having no hollow portion, and gas was not fed under pressure. did. After cooling to room temperature, the formed polyimide resin tubular product was tried to be extracted, but it could not be extracted because it adhered to the support.

At this time, the coefficient of linear thermal expansion of the stainless steel constituting the support is 1.7 × 10 ⁻⁵ cm / cm / ° C., whereas the coefficient of linear thermal expansion of the polyimide resin tubular product is 3.
It was as large as 5 × 10 ⁻⁵ cm / cm / ° C.

[Brief description of drawings]

FIG. 1 is a side view of a support used in the present invention.

FIG. 2 is a cross-sectional view showing a state in which a tubular object is inserted in the support body of FIG.

FIG. 3 is a cross-sectional view showing a state in which gas is being fed with a tubular object inserted in the support of FIG.

[Explanation of symbols]

1 support 2 pores 3 Hollow part 4 Solidified tubular objects 5 Gas pump 6 entrance 7 Heat-resistant resin tubular material

Continued front page    F-term (reference) 4F205 AC05 AD12 AE01 AG08 AH12                       GA01 GB01 GC01 GD02 GF03                       GF24 GN13 GN29                 4F213 AA40 AG16 WA03 WA22 WA39                       WA53 WA58 WA87 WA92 WB01                       WC03 WF24 WK03 WW06 WW15                       WW21

Claims (2)

[Claims] 1. A step of applying a heat-resistant resin material solution to a cylindrical mold surface, solidifying by heating and drying until self-supporting, and then peeling the solidified tubular product from the mold surface,
In the method for producing a heat-resistant resin tubular product, which comprises a step of firing a support having an outer diameter smaller than the inner diameter of the tubular product in the tubular product, the support is hollow and its upper end is closed. , Which has pores on the side surface thereof, and after the firing step is completed, gas is pressure-fed to the hollow portion of the support, and gas is introduced between the outside of the support and the heat-resistant resin tubular material through the pores on the side surface. And a step of peeling off the heat-resistant resin tubular product from the support by injecting. 2. The manufacturing method according to claim 1, wherein the heat-resistant resin tubular material has a coefficient of linear thermal expansion larger than that of the support.