JP2002210846A - Composite tubular matter and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite tubular matter of a polyimide which enables prevention of lowering of the strength of a polyimide base layer and improvement of thermal conductivity and can correspond to a high speed, by forming an anchor layer of metal powder on the surface of the polyimide base layer and by forming a release layer on the surface of the anchor layer. SOLUTION: The base of the composite tubular matter 10 is made of the polyimide 1 and the powdered metal anchor layer 2 is formed as the outer layer thereof, while the release layer 3 of a fluoroplastic or the like is formed as the surface layer of the layer 2. As for a method of manufacturing the matter, a polyimide precursor liquid is cast on the outer surface of a molding core of the polyimide tubular matter and the metal powder is stuck on the molding outer surface of the polyimide precursor before this is converted into the imide, so that the metal anchor layer be made. After the conversion into the imide, thereafter, the release layer 3 is formed by sintering on the surface of the metal anchor layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide resin composite tubular article and a method for producing the same. More specifically, the present invention relates to a polyimide resin composite tubular article obtained by imide conversion from a polyimide resin precursor, which is used in a fixing device such as a copying machine or a printer, and a method for producing the same.

[0002]

2. Description of the Related Art Polyimide resins have excellent heat resistance, dimensional stability, mechanical properties, and chemical properties, and are used for intermediate purposes such as heat fixing belts for copiers and laser beam printers and toner images. Used in a wide range of fields such as transfer belts. An example of the application is a heat fixing belt for a copying machine or a laser beam printer (for example, Japanese Patent No. 3054010).

Here, a description will be given of an example of a polyimide composite tubular article used as a fixing part of a copying machine or a laser beam printer. In a copier or a laser beam printer using electrophotography, a heat roller method, that is, a fixing roller having a heating mechanism as a fixing device for fixing a toner image formed on copy paper or transfer paper, is pressed against the fixing roller. There is a method in which copy paper on which a toner image is formed is sequentially fed between both rollers of a pressure roller, the toner is heated and melted, and the toner image is fixed on the copy paper. As a method for reducing electric energy at the time of fixing, or a method for shortening a waiting time from power-on to copying, there is a method called an on-demand method. In this method, technical development has been advanced to a belt fixing method using a polyimide resin tubular article, and a ceramic heater 63 and a film guide 62 are provided inside the polyimide resin tubular article 10 as shown in FIG.
In this method, the toner 67 is heated and melted while the copy paper 66 on which the toner image 67 is formed is sequentially fed between the pressure roll 64 pressed against the heater 63 and the toner image is fixed on the copy paper. In the figure, 65 is a thermistor, 68 is a fixed material, 69 is a core of a pressure roll, and N is a nip point. In a conventionally used polyimide resin tubular article, a base material is a polyimide resin, and a fluororesin layer is formed on an outer layer thereof with or without a primer layer.

[0004]

In recent years, the on-demand type fixing device has been required to have a higher copying speed.

[0005] However, the conventional polyimide resin tube has a heat insulating material as a main component, and therefore, does not have high thermal conductivity and cannot meet the demand for higher speed.
In this regard, it has been proposed to mix an inorganic powder such as boron nitride in the polyimide resin.However, if the inorganic powder is mixed in a large amount to improve the thermal conductivity, the strength of the polyimide resin itself may decrease. There was a problem that it would.

SUMMARY OF THE INVENTION The present invention provides a polyimide resin composite tubular article capable of improving thermal conductivity without reducing the strength of the polyimide layer and capable of coping with high speed, and a stable and easy solution. It is an object of the present invention to provide a manufacturing method.

[0007]

In order to achieve the above object, a composite tubular article of the present invention has a substrate in which a powdery metal anchor layer is formed on the outer layer of a polyimide resin tubular article, and the surface thereof has It is characterized by including a release layer.

In the method for producing a composite tubular article according to the present invention, a polyimide precursor solution is cast-molded on an outer surface of a core for molding a polyimide tubular article, and a metal powder is attached to the outer surface of the polyimide precursor before the imide conversion. After that, a metal anchor layer is formed, and after the imide conversion, a release layer is formed on the surface of the metal anchor layer.

[0009]

In the present invention, the average particle diameter of the powder metal constituting the metal anchor layer is 50 μm.
The following is preferred.

It is preferable that the release layer is at least one layer selected from a silicone rubber layer, a fluororesin layer and a fluororubber layer.

Preferably, the release layer is a fluororesin layer or a laminate in which a silicone rubber layer is formed as an inner layer and a fluororesin layer is laminated on the surface thereof.

Further, it is preferable that the composite tubular article is used for a fixing belt heated by a heating element from the inside.

The average thickness of the polyimide resin layer of the substrate is preferably in the range of 30 to 500 μm.

In the method of the present invention, the means for adhering the metal powder to the outer surface of the polyimide precursor before the polyimide precursor liquid is formed on the outer surface of the core and subjected to imide conversion includes spraying, powder bubbling, and magnetic attraction. Preferably, the method is at least one method selected from the following.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a composite tubular article 10 according to one embodiment of the present invention. In the figure, a release layer 3 is formed on the outer layer of a polyimide tubular article 1 as a base material via a powdery metal anchor layer 2.

The average particle diameter of the powder metal forming the metal anchor layer 2 is preferably 50 μm or less. The metal anchor layer 2 is not formed alone, but is partially or mostly embedded in the polyimide tubular article 1.

When the metal powder 2 is laminated on the outer surface of the polyimide tubular article 1, the metal powder layer 2 improves the thermal conductivity and enables high-speed fixing.

In the above structure, a method for forming a tubular article using a polyimide precursor liquid as a base material is described in, for example, Japanese Patent No. 305.
No. 4010, but is not limited thereto. Cast the polyimide precursor liquid to a certain thickness on the outer surface of the cylindrical core body by the above method and the like, and then apply the metal powder by spraying the metal powder before imide conversion, or by magnetic attraction. It is preferred to complete the drying and then the imidization. In this way, the powdery metal forming the anchor layer is embedded only in the surface of the polyimide precursor liquid cast layer, or a mixture of those adhering to the surface,
It can be firmly integrated with the release layer 3 formed on the surface of the powdery metal layer later. Therefore, even if the heat cycle of the heat generation and the cooling is repeated, no peeling occurs.

In the above, the average particle diameter of the metal powder is 5
0 μm or less, more preferably an average particle diameter of 5
１５15 μm. Within the above range, an anchoring effect on the polyimide layer and sufficient thermal conductivity can be obtained. When the average particle diameter of the metal powder exceeds 50 μm, the surface roughness of the composite tubular article becomes rough. Also, if the metal powder is too fine, secondary agglomeration, the amount of adhesion on the polyimide precursor surface varies,
Eventually, this also affects the lamination thickness of the release film. The phenomenon that the metal powder settles inside the polyimide precursor molding layer during the metal powder lamination process also affects the viscosity of the polyimide precursor liquid or the speed and strength at which the metal powder is conveyed to the polyimide precursor surface. Therefore, appropriate conditions can be found in advance by experiments.

The material of the metal powder used in the present invention is not particularly limited, and various metal powders can be used alone or as a mixture. When the metal powder is deposited by magnetic force, a magnetic metal powder is useful, and nickel, iron, cobalt and the like are more preferable materials.
Also, the shape of the metal powder is not particularly limited, but is preferably in the form of a scale or a single plate.

Further, it is preferable that a release layer 3 of any one of a silicone rubber layer, a fluorine rubber or a fluorine resin layer is laminated on the outer layer of the metal anchor 2 of the polyimide-based tubular article of the present invention. As the release layer 3, silicone rubber, fluoro rubber, fluoro resin, or the like can be used. It is preferable that any one of these materials be laminated, because it is possible to prevent the toner melted at the time of fixing the toner from adhering to the outermost surface of the polyimide tubular material and retransferring to the copy paper (offset phenomenon). The silicone rubber layer is a preferable material because the elasticity of the silicone rubber is useful for mixing the fused toner image of the basic color in fixing the color toner. The average thickness of the silicone rubber layer is preferably in the range of 50 to 500 μm. Fluorine rubber can be used as well as silicone rubber.
The type of the fluororesin material is not particularly limited, and polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) can be used. It can be used alone or in a mixture. PFA is a preferable material in terms of heat resistance and durability. The average thickness of the fluororesin layer is also preferably in the range of 10 to 30 μm. Also, tubes of these materials can be coated.

The composite tubular article 10 of the present invention can be used as a conventional on-demand type heat fixing belt shown in FIG.

According to the production method of the present invention, the polyimide precursor liquid is molded on the outer surface of the core, the metal powder is attached to the outer surface of the polyimide precursor before the imide conversion, and then the imide conversion is carried out. Layer, a fluororubber layer or a fluororesin layer. Further, the means for forming the polyimide precursor liquid on the outer surface of the core body and attaching the metal powder to the outer surface of the polyimide precursor before the imide conversion is performed by any of spraying, powder bubbling, and magnetic attraction. Is preferred.

If the metal powder is laminated before the polyimide precursor liquid is cast and converted to imide, and the imidization is completed thereafter, the metal powder is firmly adhered to the outer surface of the polyimide tube, and has an anchoring effect. It is preferable because the adhesive strength with the release layer to be subsequently laminated can be strengthened.

Hereinafter, the polyimide resin composite tubular article of the present invention and a method for producing the same will be described according to typical embodiments.

The polyimide resin composite tubular product of the present invention is prepared by polymerizing an aromatic tetracarboxylic acid component and an aromatic diamine component in a polar organic solvent to produce a polyimide precursor solution. According to the method of manufacturing a tubular article, apply to the outer surface of a cylindrical mold, then perform lamination of a metal powder, and then use a heating ring closure or a chemical ring closure method to perform an imide conversion to form a basic base tubular article. Can be manufactured.

Thereafter, a metal powder is formed as an anchor layer, and a release layer such as silicone rubber, fluoro rubber or fluoro resin is laminated thereon to complete the composite tubular article of the present invention.

The following are typical examples of the aromatic tetracarboxylic acid. Pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3,4,4 '-Biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride,
1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) ether dianhydride, a tetracarboxylic acid ester thereof, or a mixture of the above tetracarboxylic acids may be used.

On the other hand, there is no particular limitation on the aromatic diamine component. , 3,3'-dimethoxybenzidine, 4,4'diaminodiphenylpropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane and the like.

In the method of the present invention, a tubular article is manufactured using a composition (raw material) in which a polyimide precursor is dissolved in an organic polar solvent. As the organic polar solvent, dimethylacetamide, dimethylformamide, N-methyl-
2-pyrrolidone, phenol, o-, m-, p-cresol and the like. These organic polar solvents may be mixed with hydrocarbons (hydrocarbons) such as xylene, hexane, and toluene.

If necessary, a polyimide precursor solution obtained by polymerizing an aromatic tetracarboxylic acid component and an aromatic diamine component in an organic polar solvent may contain boron nitride,
A heat conduction improver such as alumina, silicon carbide, silica, titanium oxide, and metal powder may be mixed. The shape of the heat conductive filler may be any of a sphere, a scale, and a fiber, but is preferably a sphere in order to ensure the smoothness of the surface of the tubular material. More preferably, the average particle diameter is 1 to
20 μm spherical particles can be mentioned.

According to the above-described polyimide composite tubular article of the present invention, the polyimide precursor liquid is cast on the outer mold surface of the cylindrical core to a predetermined thickness, and then the metal powder is formed before the imide conversion. When applied by spraying or magnetic attraction, followed by drying and imide conversion, the inner surface of the composite tubular material is a pure polyimide layer, and metal powder can be laminated on the outer layer as an anchor layer. The durability is improved without impairing the mechanical properties of the steel.

Further, the metal powder is accumulated on the outermost layer of the cast surface of the polyimide precursor by electromagnetic force or the like, and then converted into an imide to form a composite tubular article. Therefore, the metal powder is firmly fixed to the surface of the tubular article. The individual metal particles come into contact and are fixed. Therefore, when a release layer is formed on the surface, a sufficient adhesive force can be obtained. That is, in the prior art, since the metal powder or the like was previously mixed into the polyimide precursor liquid, the mechanical properties of the polyimide resin layer were significantly reduced.

If any one of a silicone rubber layer, a fluorine rubber layer and a fluororesin layer is laminated on the outer layer of the metal powder anchor layer of the polyimide-based tubular material, the toner melted at the time of fixing the toner will have a surface. , And retransfer (offset phenomenon) to copy paper can be prevented. In addition, the silicone rubber layer is a preferable material because the elasticity of the silicone rubber is useful for mixing color of a fused toner image of a basic color in fixing a color toner. The thickness of the silicone rubber layer is preferably from 50 to 500 μm. The type of the fluororesin material is not particularly limited, and PTFE, PFA, and FEP can be used alone or as a mixture. PFA is a preferable material in terms of heat resistance and durability. The thickness of the fluororesin layer is also preferably 10 to 30 μm. Also, tubes of these materials can be coated.

[0036]

The present invention will be described more specifically with reference to the following examples.

(Example 1) Outer diameter 35 mm, length 500
A cylindrical aluminum mold (cylindrical core) having a thickness of 3 mm and a thickness of 3 mm was prepared. The surface of this mold was coated with a silicon oxide coating agent by a dipping method,
The film was baked by heating at 0 ° C. for 30 minutes and at 380 ° C. for 30 minutes, and covered with a silicon oxide film having an average thickness of 1 μm.

Next, as a first step, a polyimide precursor solution having a viscosity of 1500 poise (trade name “R” manufactured by IST Co., Ltd.)
C5063PyreML Varnish ").
After being immersed to a 0 mm portion and taken out with the varnish attached, a ring-shaped die having an inner diameter of 36.5 mm was inserted from the top of the mold and allowed to run, and a polyimide precursor having a thickness of 750 μm was placed on the surface of the mold. The body fluid was cast molded.

Thereafter, as shown in FIG. 3 (a), a permanent magnet 35 is inserted inside the mold (cylindrical core) 31 so that both ends of the mold (cylindrical core) 31 are driven bearings. 36 and the driven bearing 36 '(FIG. 3 (b)).
at a speed of m. At the same time the average particle diameter is 12 μm
Was placed in a tray 34 and set at a distance of 20 mm below a horizontally disposed mold (cylindrical core) 31 having the polyimide precursor liquid layer 32 formed by casting. Thereafter, the motor 37 is driven and rotated for 2 minutes to remove the permanent magnet 35 from the mold (cylindrical core) 31.
Was removed and spun for another minute. A tubular intermediate was obtained in which nickel powder was uniformly and densely applied to the outermost surface of the polyimide precursor cast-molded.

Thereafter, as the first imide conversion treatment, 1
After drying in an oven at 20 ° C. for 60 minutes, the temperature was raised to a temperature of 200 ° C. in 40 minutes, kept at the same temperature for 20 minutes, and further heated at 320 ° C. for 40 minutes and at 400 ° C. for 20 minutes to obtain a polyimide precursor solution. After the imide conversion was completed, the product was taken out of the oven and cooled, and then the mold and the tubular material were separated to produce a desired polyimide tubular product.

The inner diameter of this tubular article was 35 mm, the average thickness of the polyimide tubular article containing the metal powder layer was 79 μm, and the surface roughness (Rz) of the tubular article was measured to be 3.7 μm.

Next, as a second step, the composite tubular article obtained in the first step is inserted into a stainless steel pipe having an outer diameter of 35 mm, the lower portion is masked, and a fluororesin primer solution (trade name “Teflon” manufactured by DuPont) is used. 855-003 ")
And coated to a thickness of 4 μm. Then 2
It was dried at a temperature of 00 ° C. for 30 minutes and cooled again to room temperature.

Next, as a third step, a PTFE dispersion (trade name “Teflon 855- manufactured by DuPont”) is used.
510 ”), lifted up, coated to a thickness of 10 μm, 200 ° C. for 10 minutes, 320 ° C. for 40 minutes, 400
After heating at 20 ° C. for 20 minutes, a tubular article coated with the baked PTFE resin on the surface of the composite tubular article was obtained. The inner diameter of this tubular article is 35 mm, the total thickness including the PTFE resin is 94 μm, and the surface roughness of the tubular article is Rz 1.2 μm.
Met.

The polyimide composite tubular article 10 thus obtained was assembled in a fixing machine having a ceramic heater as shown in FIG. 2, and a paper passing durability test of monochrome copying was performed at a copying speed of 24 sheets per minute. The paper passing durability was obtained.

(Example 2) A tubular intermediate which was completed up to the first step under the same conditions as in Example 1 was obtained. This tubular intermediate was inserted into a stainless steel core, and a primer for silicone rubber “DY-39-O067” (manufactured by Dow Corning Toray) was coated on the surface of the tubular material, and dried at room temperature.
Then, liquid silicone rubber "DY-35-4002"
(Manufactured by Toray Dow Corning) is adhered to the upper part of the tubular object, and a ring-shaped die having an inner diameter of 35.5 mm is run by its own weight, and
The silicone rubber was coated to a thickness of 50 μm.

Thereafter, at a temperature of 150 ° C. for 40 minutes, 20
Vulcanization was performed at a temperature of 0 ° C. for 5 hours to obtain a tubular article whose outer layer was coated with silicone rubber. Then, a fluororesin dispersion "AD-1" is further applied to the surface of the silicone rubber.
(Made by Asahi Glass) was spray-coated to a thickness of 10 μm (thickness after drying), and baked at a temperature equal to or higher than the melting point of the fluororesin to obtain a target composite tubular article. When this tubular portion was incorporated into the printer having the ceramic heater of Example 1 and color copying was performed, a good image could be obtained.

Example 3 A polyimide precursor was cast in a mold in the same manner as in Example 1. Thereafter, both ends of the mold were placed horizontally on a driven bearing of the apparatus shown in FIG. 3 (without a permanent magnet), and rotated at a speed of 8 rpm. At the same time, 0.5 μm of silver powder having an average particle diameter of 10 μm was added.
It was sprayed while being moved in the length direction of the mold under a pressure of kg / cm ² to obtain a tubular intermediate in which a silver powder was uniformly and densely applied to the outermost surface of the polyimide precursor cast and molded.

Thereafter, imide conversion was carried out under the same conditions as in Example 1, and after cooling, the mold and the tubular material were separated to produce the desired polyimide tubular material. The inner diameter of this tubular object is 3
5 mm, the thickness of the polyimide tube containing the silver powder layer is 7
8 μm, and the surface roughness of the tubular article was measured.
It was 2.5 μm.

Next, the second and third steps were carried out in the same manner as in Example 1.

The polyimide composite tubular article 10 thus obtained was assembled in a fixing machine having a ceramic heater as shown in FIG. 2, and a paper passing durability test of monochrome copying was performed at a copying speed of 24 sheets per minute. The paper passing durability was obtained.

Comparative Example 1 A polyimide resin precursor was cast in a mold in the same manner as in Example 1. afterwards,
The imide conversion treatment was performed under the same conditions as in Example 1, and the inner diameter was 3
A 5 mm polyimide tube having an average thickness of 74 μm was obtained.
This tubular article was treated under the same conditions as the second and third steps of Example 1 to obtain a tubular article coated with a fluororesin primer and a polytetrafluoroethylene resin. The total thickness of the thus obtained tubular article without a metal layer was 89 μm, and the surface roughness Rz was 1.0 μm. This tubular article was assembled in a fixing machine having a ceramic heater as shown in FIG. 2 and a paper passing durability test of monochrome copying was performed at a copying speed of 4 sheets per minute. As a result, only 50,000 sheet passing durability was obtained.

(Comparative Example 2) A spherical nickel powder having an average particle diameter of 4 µm was previously mixed in a uniform amount of 50 wt% with respect to the solid content of the polyimide precursor liquid in the polyimide precursor liquid. A polyimide tube was manufactured in the same manner as in the first step of Example 1 except that there was no coating step. This tubular article was treated under the same conditions as the second and third steps of Example 1 to obtain a tubular article coated with a fluororesin primer and a polytetrafluoroethylene resin. The total thickness of the thus obtained tubular article without a metal layer was 90 μm, and the surface roughness Rz was 1.2 μm. This tubular article was assembled in a fixing machine having a ceramic heater as shown in FIG. 2 and subjected to a paper passing durability test for monochrome copying. The tubular article was not strong enough and was broken in a short time.

[0053]

As described above, the present invention reduces the strength of the polyimide substrate layer by forming an anchor layer made of metal powder on the surface of the polyimide substrate layer and forming a release layer on the surface. The present invention can provide a polyimide resin composite tubular article capable of preventing heat generation, improving thermal conductivity, and responding to high speed, and a method for stably and easily manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a sectional view of a composite tubular article according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fixing device according to a conventional example and an embodiment of the present invention.

FIG. 3 is a sectional view of an apparatus for forming an anchor layer for manufacturing a composite tubular article according to one embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 polyimide tubular article as base material 2 metal anchor layer 3 release layer 10 composite tubular article 31 mold (cylindrical core) 32 polyimide precursor liquid layer cast-formed 33 nickel powder 34 tray 35 permanent magnet 36 driven bearing 36 'driven bearing 37 motor 62 film guide 63 ceramics heater 64 pressure roll 65 thermistor 66 copy paper 67 toner image 68 fixed matter 69 core metal of pressure roll N nip point

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 27/30 B32B 27/30 DF Term (Reference) 4F100 AB00B AB16 AK17C AK17D AK18 AK49A AK52C AN02C AN02D BA04 BA07 BA10D DA11 DE01B EC15B EH76 EJ42 EJ65 GB41 GB51 JL02 JL14 JL14C

Claims (10)

[Claims] (1) The base material is an outer layer of a polyimide resin tubular material,
A composite tubular article having a powdery metal anchor layer formed thereon and including a release layer on its surface. 2. The composite tubular article according to claim 1, wherein the average particle diameter of the powder metal forming the metal anchor layer is 50 μm or less. 3. The composite tubular article according to claim 1, wherein said release layer is at least one layer selected from a silicone rubber layer, a fluororesin layer, and a fluororubber layer. 4. The composite tubular article according to claim 3, wherein the release layer is a fluororesin layer or a laminate in which a silicone rubber layer is formed on an inner layer and a fluororesin layer is laminated on the surface thereof. 5. The composite tubular article according to claim 1, wherein the composite tubular article is used for a fixing belt heated by a heating element from the inside. 6. An average thickness of the polyimide resin layer of the substrate is 30.
The composite tubular article according to any one of claims 1 to 5, wherein the diameter of the composite tubular article is in a range of from about 500 µm to about 500 µm. 7. A polyimide precursor liquid is cast-molded on the outer surface of a core for forming a polyimide tubular article, and a metal powder is attached to the outer surface of the polyimide precursor before the imide conversion. Forming a release layer on the surface of the metal anchor layer. 8. The means for adhering the metal powder to the polyimide precursor molding outer surface before molding the polyimide precursor liquid on the outer surface of the core and converting the polyimide precursor to imide is at least one selected from spray, powder bubbling and magnetic attraction. The method for producing a composite tubular article according to claim 7, which is a method. 9. The method according to claim 7, wherein the release layer is at least one layer selected from a silicone rubber layer, a fluororesin layer, and a fluororubber layer. 10. The production of a composite tubular article according to claim 9, wherein the release layer is a fluororesin layer or a laminate in which a silicone rubber layer is formed on an inner layer and a fluororesin layer is laminated on the surface thereof. Method.