JP2693802B2 - Composite tubular article and method for producing the same - Google Patents

Description

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

[Conventional technology]

Conventionally, as a method for fixing an image on a transfer paper or the like in the image forming apparatus, a fixing method combining heat, pressure, or both has been proposed. Specifically, an oven fixing method, a flash fixing method, The pressure fixing method, the heat roller fixing method and the like can be mentioned. Above all, the heat roller fixing method is widely adopted from the viewpoints of thermal efficiency, danger of ignition, fixing characteristics and the like.

As shown in FIG. 4, the heat roller fixing method is a method in which the heat roller 18 and the press roller 20 are vertically opposed to each other, and the transfer paper 14 is passed between the rollers 18 and 20.
The built-in fixing heater 19 heats and melts the heat-sensitive ink 9 which is the object to be fixed on the transfer paper 14, and the pressure is applied by the press roller 20 to strengthen the fixing, whereby the heat-sensitive ink 9 on the transfer paper 14 is fixed. To form an image. In this case, in order to prevent the thermal ink 9 or the transfer paper 14 having the thermal ink 9 fixed thereon from adhering to the heat roller 18 after fixing, a fluorine compound is coated on the surface of the heat roller 18, or the surface of the coating layer is further coated. It is practiced to apply silicone oil to the. Further, since the above-mentioned processing alone is insufficient to prevent the thermal ink 9 and the transfer paper 14 from adhering to the heat roller 18, in addition to the above-mentioned processing, as shown in FIG.
Separation claws 21 are provided so as to slightly touch the surface of 18 to prevent the thermal ink 9 and the transfer paper 14 having the thermal ink 9 fixed thereto from adhering to the thermal roller 18. However, when the separation claw 21 is provided in the image forming apparatus as described above, the image forming apparatus becomes expensive and the mechanism of the apparatus becomes complicated, which causes a problem of frequent troubles.

On the other hand, in order to fix the heat-sensitive ink 9 to the transfer paper 14, the temperature of the heat roller 18 must be raised to the temperature required for fixing. However, if the temperature is set too high, the heat-sensitive ink 9 itself may slightly increase. Due to the adhesiveness, the heat-sensitive ink 9 may not be completely peeled off from the heat roller 18. As a result, the quality of the image surface formed on the transfer paper 14 becomes insufficient, and peeling electrification occurs on the transfer paper 14 due to resistance at the time of peeling from the heat roller 18, and dust adheres,
There arises a problem that the heat roller 18 and the separation claw 19 are charged with static electricity.

In order to solve the above-mentioned problems, for example, in addition to the heat roller 18 and the press roller 20, a peeling roller (not shown) is used as a third roll, which is disposed on the side of the heat roller 18. Then, between the heat roller 18 and the peeling roller, a fixing belt made of a flexible composite tubular material made of a fluorine resin and a polyimide resin is bridged, and the belt and the press roller 20.
A method of passing the transfer paper 14 with the thermal ink 9 between them is being studied. The fluorine resin used for the fixing belt has excellent releasability, chemical resistance, and heat resistance, and has been conventionally widely used as a release agent, a sealing material, and the like. Also,
The polyimide resin is excellent in heat resistance, chemical resistance, electrical insulation, mechanical properties and the like. Therefore, the intent of adopting the fixing belt made of the composite tubular material is to form a fluorine resin layer excellent in heat resistance and peelability as an outer layer in the fixing belt, and to improve heat resistance, electric insulation and mechanical properties. By forming a polyimide resin layer with excellent characteristics in the inner layer,
It is to improve transfer peeling property easily and effectively. A method for manufacturing such a composite tubular article is disclosed in Japanese Patent Laid-Open No. 61-
It is described in Japanese Patent Publication No. 95361. That is, the above-mentioned manufacturing method comprises mixing the conductive fine powder with a precursor solution of a polyimide resin to prepare a mixed solution, and injecting this into a large-diameter cylindrical mold and centrifuging while heating to form the inner circumference of the cylindrical mold. A thin layer is formed on the surface along the circumference, and an endless belt (with a conductive layer) is formed from this thin layer. Then, a fluorine resin is spray-coated on the surface of the conductive layer of the belt to form a dielectric layer, and a non-photosensitive dielectric belt is manufactured.

[Problems to be solved by the invention]

However, in the above-mentioned manufacturing method, when the outer surface of the conductive polyimide layer is spray-coated with the fluorine resin dispersion (dispersion liquid), uneven coating is likely to occur. Therefore, there is a problem that a tubular material having a uniform thickness of each layer and a smooth surface cannot be obtained, and when it is used for a fixing belt, it is difficult to obtain a uniform and glossy image. .

The present invention has been made in view of such circumstances, and an object thereof is to provide a composite tubular article in which the adhesion between layers is strong and the surface is smooth and the thickness of each layer is uniform, and a method for producing the same. To do.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention is a composite tubular product obtained by forming on the inner peripheral surface of a cylinder and then pulling it out, and applying a fluorine resin solution to the inner peripheral surface of the cylinder and curing it in a layered form. The first gist is a composite tubular article including the formed fluororesin tubular outer layer and a polyimide resin tubular inner layer integrally formed on the inner circumferential surface of the tubular outer layer, and a polyamide is provided on the inner circumferential surface of the cylinder. A composite tubular body comprising a polyimide resin tubular inner layer formed by applying an acid solution, imidizing it, and curing it in a layered state and drawing it out, and a fluorine resin tubular outer layer integrally formed on the outer peripheral surface of the tubular inner layer. In the second gist, the fluorine resin solution is applied to the inner peripheral surface of the cylinder to form a fluorine resin tubular product, and the polyamic acid solution is applied to the inner peripheral surface of the fluorine resin tubular product. No bullet A spherical running body is run along the inner peripheral surface of the coating of the polyamic acid solution, and then the polyamic acid is imidized to form a polyimide tubular product, and after the formation, the composite tubular product is taken out of the composite tubular product from the cylinder. According to the third aspect of the method, a polyamic acid solution is applied to the inner peripheral surface of a cylinder, and a bullet-shaped or spherical traveling member is caused to travel along the inner peripheral surface applied with the polyamic acid solution to imidize the polyamic acid. To form a polyimide tubular product, take out the polyimide tubular product from the cylinder after formation, and then immerse the polyimide tubular product in a fluorine resin solution to form a polyimide tubular product having a thickness of 1 to 10 μm on the outer peripheral surface.
The fourth gist of the present invention is a method for producing a composite tubular article, which comprises forming a fluorine resin layer having a surface roughness of 1 μm or less.

[Action]

That is, the present invention, first, to apply a fluorine resin solution to the inner peripheral surface of the cylinder to form a fluorine resin tubular product on the inner peripheral surface, further apply a polyamic acid solution to the inner peripheral surface, In this state, a bullet-shaped or spherical traveling member is caused to travel along the inner peripheral surface to form a polyamic acid solution in a uniform film shape, and at the same time, the polyamic acid solution is pressure-bonded to the fluororesin tubular product, and then the polyamic acid is imidized. Further, contrary to the above, on the inner peripheral surface of the cylinder, first, a polyamic acid solution is applied, and in that state, a bullet-shaped or spherical traveling member is made to travel along the inner peripheral surface so that the polyamic acid solution has a uniform thickness. It is formed into a film, and then polyamic acid is imidized to form a polyimide tubular product having a specific thickness. Then, take out the polyimide tubular product from the cylinder,
This is immersed in a fluorine resin solution to form a fluorine resin layer having a specific thickness on the outer peripheral surface of the polyimide tubular material. As a result, the outer peripheral surface of the fluorine resin layer is extremely smooth, the centering is performed accurately, and coating unevenness does not occur, so that a composite tubular article having a uniform thickness of each layer can be obtained. Moreover, the manufacturing method of the endless product becomes easy.

In the present invention, a composite tubular article is manufactured using a fluorine resin and a polyamic acid.

The fluororesin is used in the form of a solution (including suspension), and for example, commercially available polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP) , Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) and the like.
The viscosity of the fluorine resin dispersion is adjusted according to the coating thickness and the temperature of the dispersion by adding, for example, a surfactant or a thickener to the fluorine resin dispersion, , 0.1 to 100 poise (measured with a B-type viscometer at the temperature during coating operation).
In addition, the melt viscosity of fluorine resin is 6 × 10 ⁶ poise (temperature 372
(° C.) Or less is preferable because it is easy to obtain a smooth surface having a surface roughness (average roughness at 10 points) of the fluorine resin layer of the obtained composite tubular product of 1 μm or less. The concentration of such fluorine resin dispersion is usually set to 5 to 60% by weight (hereinafter abbreviated as "%"), and more preferably 20 to 60%.

In addition, it is effective and preferable to use the above-mentioned fluorine resin dispersion containing a conductive substance, when the obtained composite tubular product is used as a fixing belt of a copying machine or the like. Examples of the conductive substance include conductive powders such as carbon, graphite, and metal powders, and organic compounds having conductivity. Particularly, conductive powders such as carbon, graphite, and metal powders are preferably used. The content of the conductive material is preferably set within the range of 2 to 50% in the fluorine resin.

The polyamic acid is obtained by reacting tetracarboxylic dianhydride or its derivative with approximately equimolar amounts of diamine in an organic polar solvent, and is used in the form of a solution.

Examples of the tetracarboxylic dianhydride include those represented by the following general formula.

For example, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4 '
-Biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'
-Biphenyl tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 1,2,5,6-naphthalene tetracarboxylic acid dianhydride, 1,4,5,8- Naphthalene tetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, perylene-3,4 ,
Examples thereof include 9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, and ethylenetetracarboxylic dianhydride.

Further, as the diamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane,
3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-aminodiphenyl sulfide-3,3 '
-Diaminodiphenyl sulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl-4,4'-biphenyldiamine, paraphenylenediamine, metaphenylenediamine, benzidine , 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,
4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl propane, 2,4-bis (β-amino-tert-butyl) toluene, bis (p-β-amino-tert-butylphenyl) ether, Bis (p-β-methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-5)
-Amino-pentyl) benzene, 1-isopropyl-2,
4-metaphenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyl Tetramethylenediamine, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-
Diamine nododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3 -Methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,11-diaminododecane, 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 (C
H ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ N
_{H 2, N 2 H (CH} 2) 3 N (CH 3) (CH 2) 3 NH 2 and the like.

Further, the organic polar solvent used in the synthesis of the polyamic acid has a dipole whose functional group does not react with tetracarboxylic dianhydride or diamine.
In addition to being inert to the system and acting as a solvent for the product polyamic acid, it must act as a solvent for at least one of the reaction components, preferably both. Particularly, as the organic polar solvent, N, N-dialkylcarboxylic amides are useful, and examples thereof include low molecular weight compounds such as N, N-dimethylformamide and N, N-dimethylacetamide. These can be easily removed from the polyamic acid and polyamic acid moldings by evaporation, displacement or diffusion. Further, as an organic polar solvent other than the above, N,
N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methyl-2-pyrrolidone, pyridine, dimethylsulfone, tetramethylenesulfone, dimethyltetramethylenesulfone , Dimethylacetamide, dimethylformamide, dimethylsulfoxide, hexamethylenephosphortriamide and the like. These may be used alone,
It can be used together. Further, in the above organic polar solvent, phenols such as cresol, phenol, xylenol, benzonitrile, dioxane, butyrolactone, xylene, cyclohexane, hexane, benzene,
Toluene and the like can be mixed alone or in combination, but the addition of water is not preferred. That is, it is necessary to synthesize the polyamic acid under substantially anhydrous conditions.

Polyamic acid is obtained by reacting the above tetracarboxylic dianhydride (A) and diamine (B) in an organic polar solvent. At that time, the monomer concentration (concentration of A + B in the solvent) is , Are set according to various conditions. However, it is usually 5 to 30%.
Further, the reaction temperature is preferably set to 80 ° C. or lower, more preferably 5 to 50 ° C., and the reaction time is about 2 to
10 hours.

Thus, by reacting the acid component raw material and the diamine component raw material in the organic polar solvent, polyamic acid is produced, and the solution viscosity increases as the reaction proceeds. In the present invention, it is preferable to synthesize and use a polyamic acid having an intrinsic viscosity of 0.5 or more. That is, this is because the polyimide tubular article formed by using a polyamic acid having an intrinsic viscosity of 0.5 or more is particularly excellent in reliability against thermal deterioration.

The intrinsic viscosity of the polyamic acid is obtained by taking out the polyamic acid from the polyamic acid solution, dissolving the polyamic acid in a predetermined solvent and measuring the solution viscosity, and using the obtained value by the following formula.

When such a polyamic acid solution has a high viscosity at the time of use, it is diluted with an appropriate solvent to reduce the viscosity before use. For example, when the polyamic acid solution is applied to the inner peripheral surface of the fluororesin tubular product formed on the inner peripheral surface of the cylinder, the viscosity of the polyamic acid solution depends on the coating thickness, the inner diameter of the cylinder, the temperature of the solution, and the traveling body. Although it is set according to the shape and the like, it is usually set to 10 to 10000 poise (the temperature at the time of coating operation, the value measured by a B-type viscometer). Further, the polyamic acid concentration in the polyamic acid solution is preferably set to 5 to 30%, more preferably 10 to 20% from the viewpoint of the effect.

The present invention uses a fluorine resin dispersion and an organic polar solvent solution of the polyamic acid obtained as described above, for example, a composite tubular tube made of a fluorine resin and a polyimide resin by the following two methods. Manufacture things.
That is, first, as a first method, the inner peripheral surface of a heat-resistant cylinder made of metal, glass or the like having an inner diameter of 1 to 50 cm (the inner peripheral surface may be coated with silicone resin or the like to improve the releasing effect). Fluorine resin is applied. As a coating method, a method of dipping the cylinder in a fluorine resin solution and then pulling it up, supplying a fluorine resin solution near one end of the cylinder and running a bullet-shaped or spherical traveling body along the inner peripheral surface of the cylinder There are two ways to drive the vehicle, and the method can be selected appropriately according to the situation. Examples of the bullet-shaped or spherical traveling body include those made of metal, hard plastic, and hard glass. As a method of traveling the traveling body, it is possible to use compressed air pressure, gas explosive force, or the like. For example, the running body is urged, the running body is pulled by using a pulling wire, and running by its own weight (the cylinder is vertically erected to run the running body by its own weight) is performed. Further, in the above method, after the fluorine resin solution is applied to the inner peripheral surface of the cylinder, a bullet-shaped or spherical traveling member may be caused to travel along the inner peripheral surface of the cylinder, if necessary.
Then, after that, heat drying is performed. At this time, in order to make the film thickness uniform, it is preferable to hold the cylinder vertically or horizontally. The heat drying is performed to remove water in the discharge purgeon and form a fluororesin tubular product on the inner peripheral surface of the cylinder. However, void formation due to water evaporation, polyamic acid solution due to residual water content The temperature conditions and the like are set in consideration of the white turbidity phenomenon during or after coating, the reaction inhibition during imidization, the adhesion between the imidized fluorine resin and the polyimide, and the drying is performed by heating. If necessary, the temperature may be set to 100 ° C. or higher in order to completely evaporate the water. In this way, a fluorine resin coating film is obtained. Next, a polyamic acid solution is applied to the inner peripheral surface of the obtained fluorine resin coating film. In this case, through the dried state, proceed to the step of applying the polyamic acid solution, drying,
Any route may be selected which proceeds to the step of applying the polyamic acid solution through sintering (sintering). The method for applying the polyamic acid solution is performed by supplying the polyamic acid solution near one end of the cylinder and causing a bullet-shaped or spherical traveling member to travel along the inner peripheral surface of the cylinder in the same manner as described above. Then, the applied polyamic acid is imidized by heating. The heating in this imidization is first carried out at a temperature of 80-180 ° C for 20-60
Heat to remove solvent for 20 minutes at temperature 250-350 ° C.
Heating is performed for ~ 60 minutes. As a result, ring-closing water or the like generated during imidization is evaporated and imidization is completed. As a result, in the cylinder, a composite tubular product is formed in which the polyimide tubular product is laminated on the inner peripheral surface of the fluororesin tubular product. In the composite tubular article obtained as described above, the thickness of the polyimide layer was 10
In the range of up to 150 μm, and the surface roughness of the fluorine resin layer to 1 μm
It is preferably set to m or less.

In the second method, a composite tubular product is produced, for example, in the following manner using the fluorine resin and a solution of a polyamic acid in an organic polar solvent. That is, first, the polyamic acid solution is applied to the inner peripheral surface of the cylinder. As the coating method, a method of dipping the cylinder in a polyamic acid solution and then pulling it up, and supplying the polyamic acid solution near one end of the cylinder to make a bullet-shaped or spherical traveling member travel along the inner peripheral surface of the cylinder There are two methods, which are appropriately selected depending on the situation. Examples of the material of the traveling body and the method of traveling the traveling body include the same ones as described above. Further, in the above method, after applying the polyamic acid solution to the inner peripheral surface of the cylinder, a bullet-shaped or spherical traveling member may be allowed to travel along the inner peripheral surface of the cylinder, if necessary. Then, the applied polyamic acid is imidized by heating. The heating in this imidization is first carried out at a temperature of 80-180 ° C for 20-60
Heat to remove solvent for 20 minutes at temperature 250-350 ° C.
Heating is performed for ~ 60 minutes. As a result, ring-closing water or the like generated during imidization is evaporated and imidization is completed. In this way, a polyimide tubular product is obtained. In this case, the thickness of the polyimide tubular material is 10 ~
It is preferable to form it within the range of 150 μm.
Next, the obtained polyimide tubular product is taken out from the heat-resistant cylinder and immersed in a conductive fluorine resin solution to apply the fluorine resin solution to the outer peripheral surface of the polyimide tubular product. Then, heating is performed at a temperature of 80 to 180 ° C. for 10 to 30 minutes to remove the solvent, and then sintering (sintering) is performed at a temperature of 350 to 450 ° C. for 20 to 60 minutes. By such a method, a fluororesin tubular product having a thickness of 1 to 10 μm and a surface roughness of 1 μm or less can be obtained. The surface roughness is obtained by measuring the surface roughness of 10 points on the surface of the obtained fluororesin tubular product and averaging the measured values. By the way, the fluororesin solution adheres to the inner peripheral surface of the polyimide tubular article when it is immersed in the fluororesin solution, which may be wiped off with a cloth or the like. In addition to the above-mentioned dipping, examples of the method for forming the fluorine resin layer include a spray coating method and a powder coating method. In these methods, the surface roughness of the obtained fluorine resin layer is 1 μm. In the following, it is difficult to obtain a product having no coating unevenness, which is not preferable. In this case, the outer surface of the fluorine resin layer is mirror-finished (buffed) with an abrasive. The composite tubular article obtained by the above-mentioned method is usually one in which the polyimide layer 16 is formed on the inner layer and the fluorine resin layer 17 is formed on the outer layer as shown in FIG. The structure is not limited to the two layers of the fluorine resin layer and the polyimide layer, and may be formed in a multi-layer structure in which the resin layer is laminated with, for example, three layers or four layers.

The thus-obtained composite tubular article is useful in, for example, a fixing belt of an image forming apparatus because the thickness of each layer is uniformly formed within a specific range and the surface of the fluorine resin layer is smooth. Is.

Incidentally, an application example using the composite tubular article of the present invention is shown in FIG. The drawing shows a composite tubular article with an endless belt 1
FIG. 6 is a schematic view of a fixing mechanism portion of the image forming apparatus used as a transfer paper in a state in which the thermal ink 9 is not completely fixed.
Reference numeral 14 is a heat roller 18 having a fixing heater 19 and a press roller.
The heat-sensitive ink 9 is fixed on the transfer paper 14 by being inserted between the heat-sensitive ink 20 and the heat-sensitive ink. After fixing, the transfer paper 14 is conveyed to the peeling roller 22 in a state where the transfer paper 14 is adhered to the fixing belt (endless belt) 1 mounted on the heat roller 18, and due to the cooling action and the peeling property of the endless belt 1 during the conveyance. The transfer paper 14 is easily separated from the endless belt 1 and discharged. Therefore, the image formed on the transfer paper 14 is clear and excellent in quality.

〔The invention's effect〕

As described above, according to the present invention, a fluororesin solution is applied to the inner peripheral surface of a cylinder to produce a fluororesin tubular product, and a polyamic acid solution is applied to the inner peripheral surface of the cylinder, so that a bullet-shaped or spherical travel is performed. The body is run on the polyamic acid solution-coated surface to produce a composite tubular article, or the polyamic acid solution is applied to the inner peripheral surface of the cylinder to form a bullet-shaped or spherical running body on the polyamic acid solution-coated surface. To produce a polyimide tubular product by running, take out the polyimide tubular product from the cylinder and dip-coat the fluorine resin solution on the outer peripheral surface of the polyimide tubular product to produce a composite tubular product, so that uneven coating of the solution does not occur, and The thickness of each layer of the obtained composite tubular product is formed within a specific range without unevenness. Further, since the cylinder is used, the centering is precisely performed and the surface of the fluorine resin layer is formed extremely smooth. Such a composite tubular product can be formed endlessly, and is suitably used not only for a thermal transfer printer, but also for a transfer or fixing belt of a copying machine, a transfer belt for silicon wafers, a thermoplastic sheet laminating fusion belt, and the like.

 Next, examples will be described.

First, prior to the examples, two types of polyamic acid solutions were prepared as follows.

<Preparation A of Polyamic Acid Solution A> 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride and 4,4′-diaminodiphenyl ether are used in an approximately equimolar amount of N.
-Methyl-2-pyrrolidone (20% monomer concentration solution), a polyamic acid solution having a viscosity of 35,000 poise (temperature of 50 ° C, measured by a B-type viscometer) and an intrinsic viscosity of 2.8 after reacting at a temperature of 20 ° C for 5 hours Was produced. Then, 33 parts by weight of N-methyl-2-pyrrolidone was added to 100 parts by weight of this solution to dilute it, and the mixture was heated to a temperature of 50 ° C. to obtain a target viscosity of 15
A 00 poise polyamic acid solution A was obtained.

<Preparation of Polyamic Acid Solution B> Substituting 4,4′-diaminodiphenyl ether for pararafenylenediamine, a polyamic acid solution having an intrinsic viscosity of 2.5 was prepared in the same manner as above, and the desired viscosity was obtained in the same manner as above. A 3000 poise polyamic acid solution B was obtained.

[Example 1] A stainless steel cylinder having an inner diameter of 5 cm and a length of 50 cm and a smooth inner peripheral surface was dipped in a fluorocarbon resin disparyon (TE-334-J, manufactured by Deupon), and was slowly formed at a speed of 20 mm / min. Then, pull up the stainless steel cylinder at 6
After heating for 0 minutes to evaporate the water, it was further heated for several minutes at a temperature equal to or higher than the melting point, and if necessary, surface treatment was performed to enhance the film strength and obtain a fluororesin tubular product.

Next, the stainless steel cylinder on which the fluorine resin tubular material was formed was immersed in the polyamic acid solution A, filled with the polyamic acid solution, and pulled up. Then, the inside of the cylinder was run at a speed of 20 mm / min by a running method using a bullet-shaped running body having an outer diameter of 49.5 cm to apply the polyamic acid solution to the inner surface of the fluororesin tubular product. After coating, heat at a temperature of 70 ° C for 60 minutes, then raise the temperature from 70 ° C to 300 ° C at a rate of 0.8 ° C / min and heat at a temperature of 300 ° C for 60 minutes to remove the solvent, remove the ring-closing water, and imidize. After cooling to room temperature, a two-layer composite tubular product was obtained. Then, this composite tubular product was peeled from the stainless steel cylinder and taken out. A polyimide tubular product having an outer diameter of 50 mm and a length of 45 cm with both ears cut off to obtain a fluorine resin layer on the outer peripheral surface was obtained. The total thickness of the composite tubular product is 40 μm, of which the thickness of the polyimide layer is 25 μm, the thickness of the fluorine resin layer is 15 μm, and the surface roughness is 0.
It was 9 μm.

The composite tubular article obtained as described above has no coating unevenness and each layer has a uniform thickness. Furthermore, the adhesive force between the fluororesin layer and the polyimide layer is strong, and the tubular body made of the polyimide layer and the tubular body made of the fluororesin layer do not peel off. The tubular product was broken like a film.

Further, when the obtained composite tubular product was used as a fixing belt (endless belt) 1 of an ink regenerative type thermal transfer printer as shown in FIG. 3, good separation of paper after fixing of the thermal ink 9 was achieved (so-called so-called). Good offset property)
We were able to complete the fixing system. In the figure, 2
Is a platen roller, 3 is a driving roller, 4 is a back-up roller, 5, 6 and 10 are rollers, 8 is an ink tank, 9 is thermal ink, 11 is an ink tank cover, and 15 is a heater.

Example 2 A glass tube having an inner diameter of 123 mm, a wall thickness of 3 mm and a length of 50 cm and a smooth inner peripheral surface was immersed in the polyamic acid solution B, and the speed was 500 mm / min.
I lifted it up slowly. After that, the inside diameter of the glass tube
Speed of 20m by self-weight running using a 122.6mm bullet-shaped traveling body
It was run at m / min and the polyamic acid solution was applied to the inner peripheral surface of the glass tube. After coating, the mixture was heated at a temperature of 150 ° C. for 60 minutes and further at a temperature of 250 ° C. for 60 minutes to remove the solvent, remove ring-closing water and the like, imidize and cool to room temperature to obtain a polyimide tubular product.

Next, by plugging the glass tube both ends opening, by pressure-feeding air from a small through hole provided in the vicinity of the glass tube opening in advance, the resulting polyimide tubular product is peeled from the glass tube, the polyimide tubular product I pulled it out and took it out. This polyimide tubular product has an outer diameter of 123 mm, a wall thickness of 16 μm, and a length of 45 cm.
It was the one. Then, the polyimide tubular material is an FEP display purgeon (ND-1, manufactured by Daikin Co., Ltd.) in which 10% carbon (Vulcan XC-72R, manufactured by CABOT) is ultrasonically dispersed with respect to a fluorine resin content as a conductive substance. ), Speed 10
It was pulled up at 0 mm / min. Then, air dry for 10 minutes, temperature 100 ℃
After 10 minutes of drying, the FEP dispersion containing carbon adhering to the inner peripheral surface of the polyimide tubular material was wiped off with a waste cloth moistened with water. And carbon-containing FEP on the outer peripheral surface
The temperature of the polyimide tube coated with disparage
Sintering was performed at 400 ° C. for 10 minutes to obtain a polyimide tubular product (two-layer composite tubular product) having a carbon-containing FEP layer on the outer peripheral surface. The total thickness of the composite tubular product was 23 μm, of which the carbon-containing FEP layer had a thickness of 7 μm and a surface roughness of 0.7 μm.

The obtained composite tubular product had no coating unevenness and the thickness of each layer was uniform.

Next, the obtained composite tubular product was used as a fixing belt (endless belt) 1 of a copying machine as shown in FIG. 3 in the same manner as in Example 1, and the offset property was excellent and the obtained product was obtained. The images obtained were of good quality.

Comparative Example 1 The coating method of the carbon-containing FEP dispersion was changed from the dipping method to the spray coating method. Otherwise, the carbon-containing FEP is applied to the outer peripheral surface in the same manner as in the example.
A polyimide tubular product having layers (a two-layer composite tubular product) was obtained. The total thickness of the composite tubular product was 23 μm, of which the carbon-containing FEP layer had a thickness of 7 μm and a surface roughness of
It was 1.85 μm.

Next, when the obtained composite tubular article was used as a fixing belt (endless belt) of a copying machine as shown in FIG. 3 in the same manner as in Example 1, the offset property was good. The image obtained was not glossy and was of poor quality.

[Comparative Example 2] The coating method of the carbon-containing FEP dispersion was changed from the dipping method to the powder coating method. Otherwise, the carbon-containing FEP is applied to the outer peripheral surface in the same manner as in the example.
A polyimide tubular product having layers (a two-layer composite tubular product) was obtained. The total thickness of the composite tubular product was 26 μm, of which the carbon-containing FEP layer had a thickness of 10 μm and a surface roughness of
It was 2.20 μm.

Next, the obtained composite tubular product was used as a fixing belt (endless belt) of a copying machine as shown in FIG. 3 in the same manner as in Example 1. The offset property was good, but the obtained product was obtained. The obtained image was not glossy and was of poor quality.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the composite tubular article of the present invention, FIG. 2 is a schematic view of a fixing mechanism portion of an image forming apparatus using the composite tubular article of the present invention as an endless belt, and FIG. 3 is a composite article of the present invention. FIGS. 4 and 5 are schematic views of the use of an ink regeneration type thermal transfer printer using a tubular material as a fixing belt, and FIGS. 4 and 5 are schematic views of a fixing mechanism portion of a conventional image forming apparatus. 1 …… Endless belt, 16 …… Fluorocarbon resin layer 17 …… Polyimide layer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masao Nakamura 1-2 1-2 Shimohozumi, Ibaraki-shi, Osaka Within Nitto Denko Corporation (72) Inventor Tokio Fujita 1-1-1, Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Corporation

Claims (11)

(57) [Claims] 1. A composite tubular product obtained by forming on the inner peripheral surface of a cylinder and then withdrawing it, which is made of a fluororesin formed by applying a fluorine resin solution on the inner peripheral surface of the cylinder and curing it in layers. A composite tubular article comprising a tubular outer layer and a polyimide resin tubular inner layer integrally formed on an inner peripheral surface of the tubular outer layer. 2. A tubular inner layer made of a polyimide resin, which is formed by applying a polyamic acid solution to the inner peripheral surface of a cylinder, imidizing it, hardening it in a layered state, and drawing it out, and foot integrally formed on the outer peripheral surface of the inner tubular surface. A composite tubular product comprising a tubular outer layer made of a base resin. 3. A polyimide resin tubular inner layer having a thickness of 10 to 15
The composite tubular article according to claim 1, which has a diameter of 0 μm. 4. The composite tubular article according to any one of claims 1 to 3, wherein the outer peripheral surface of the fluorine resin tubular outer layer has a surface roughness of 1 μm or less. 5. The composite tubular article according to claim 1, wherein the tubular outer layer made of fluorine resin has conductivity. 6. A fluororesin solution is applied to the inner peripheral surface of a cylinder to form a fluororesin tubular product, and a polyamic acid solution is applied to the inner peripheral surface of the fluororesin tubular product to form a bullet-shaped or A spherical running body is run along the inner peripheral surface of the coating of the polyamic acid solution, and then the polyamic acid is imidized to form a polyimide tubular product, and the composite tubular product is taken out from the cylinder after formation. Manufacturing method of composite tubular products. 7. The method for producing a composite tubular article according to claim 6, wherein the thickness of the polyimide tubular article is 10 to 150 μm. 8. The surface roughness of the outer peripheral surface of the fluororesin tubular product is 1
The method for producing a composite tubular product according to claim 6, wherein the composite tubular product has a thickness of not more than μm. 9. A polyamic acid solution is applied to the inner peripheral surface of a cylinder, and a bullet-shaped or spherical traveling member is caused to travel along the inner peripheral surface applied with the polyamic acid solution to imidize the polyamic acid to form a polyimide tube. After forming the product, the polyimide tubular product is taken out from the cylinder after formation, and then the above polyimide tubular product is immersed in a fluorine resin solution, and the outer peripheral surface of the polyimide tubular product has a thickness of 1 to 10 μm and a surface roughness of 1 μm.
A method for producing a composite tubular article, which comprises forming the following fluorine resin layer. 10. A polyimide tubular product having a thickness of 10 to 150 μm.
The method for producing a composite tubular product according to claim 9, wherein 11. The method for producing a composite tubular article according to claim 6, wherein the fluororesin tubular article has conductivity.