JP2003119293A - Cross-linked fluororesin composite material and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluororesin having high toughness, abrasion resistance, radiation resistance, etc., without detriment to the properties inherent in a fluororesin, such as heat resistance, chemical resistance, water repellency, stain resistance, and lubricity. SOLUTION: The cross-linked fluororesin composite material is produced by adding a fluorinated pitch powder to a fluororesin and cross-linking the fluororesin containing the fluorinated pitch powder by heating and/or by irradiating with a radiation and has a molecularly composited network structure formed by the reaction of the fluororesin and the fluorinated pitch.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the toughness and sliding characteristics of a fluororesin by heat treatment or radiation treatment.
The present invention relates to a crosslinked fluororesin composite material having improved heat resistance and the like.

[0002]

Fluorine resins such as polytetrafluoroethylene are excellent in heat resistance, chemical resistance, water repellency, antifouling property,
It is a plastic having lubricity and abrasion resistance, and by utilizing these characteristics, its use is expanding as a material for packings for industrial and consumer use, gaskets, tubes, insulating tapes, bearings and the like. However, polytetrafluoroethylene is highly sensitive to radiation, and the irradiation dose is 1
If it exceeds kGy, the mechanical properties deteriorate, and therefore it cannot be used in a radiation environment in a nuclear facility.
In addition, it may not be used in a sliding environment due to wear and creep deformation. Further, polytetrafluoroethylene has low toughness, and if stress is applied to the material in a state where there are defects such as slight scratches, the material is immediately broken.

In order to overcome these drawbacks, measures have been taken such as modifying the fluororesin by radiation crosslinking or adding a filler or an additive. However, although radiation crosslinking can improve the problems of wear and creep deformation in a sliding environment, it does not improve toughness. When a filler or an additive is added to improve the toughness, the filler and the additive do not chemically react with the fluororesin due to the excellent heat resistance and chemical resistance of the fluororesin, and, The original excellent characteristics of the fluororesin, that is, heat resistance, chemical resistance, water repellency, antifouling property, lubricity, mechanical properties, etc. are deteriorated.

[0004]

In view of the above problems,
The object of the present invention is to lower the toughness, which has been a conventional defect of fluororesin, without deteriorating the excellent characteristics of fluororesin such as heat resistance, chemical resistance, water repellency, antifouling property and lubricity. The object is to solve problems such as abrasion and creep deformation in a sliding environment and low radiation resistance all at once, so that the fluororesin can be used in the industrial field where the use is limited.

[0005]

In order to solve the above-mentioned problems, according to the present invention, the fluororesin is crosslinked by subjecting the fluororesin containing the powder of fluorinated pitch to heat treatment and / or irradiation treatment. A cross-linked fluororesin composite material is provided, which is characterized in that it has a network structure in which molecular structure is formed by chemically reacting fluorinated pitch with fluororesin. As the fluororesin, it is preferable to use a polytetrafluoroethylene resin or a tetrafluoroethylene copolymer resin. The amount of fluorinated pitch powder added is preferably 0.05 to 50% by weight with respect to the amount of fluororesin.

Further, according to the present invention, there is provided a composite material in which the above-mentioned fluororesin is mixed with a continuous fiber material or a short fiber material to be fiber-reinforced. As the continuous fiber material or the short fiber material, PTFE fiber, glass fiber, carbon fiber, silicon carbide fiber, silicon nitride fiber, aramid fiber,
It is preferable to use one or more selected from PBO fibers and metal fibers.

Further, according to the present invention, a composite member in which the surface of a metal member is coated with the above-mentioned cross-linked fluororesin composite material, that is, a fluororesin to which a powder of fluorinated pitch is added is subjected to heat treatment and / or radiation. The surface of the metal member is coated with a fluororesin composite material in which the fluororesin is cross-linked by the irradiation treatment, and the fluororesin composite material having a network structure in which the fluorinated pitch chemically reacts with the fluororesin has a molecular composite structure. A composite member is provided. As the metal member, for example, a plate member made of aluminum, stainless steel, copper or the like or a tubular member is used.

Further, according to the present invention, there is provided the above method for producing a crosslinked fluororesin composite material, wherein the fluororesin to which the powder of fluorinated pitch is added is subjected to heat treatment and / or irradiation treatment to produce fluorine. A manufacturing method is provided, which comprises cross-linking a resin and chemically reacting a fluorinated pitch with a fluororesin. Heat treatment is 12
It is preferably carried out in a temperature range of 0 to 400 ° C. Further, it is preferable that the radiation irradiation treatment is performed in a temperature range of room temperature to 400 ° C. in an atmosphere of oxygen concentration of 0 to 200 torr, and the irradiation dose of radiation is 0.1 kGy to 10 MGy.

Further, according to the present invention, the continuous fiber material or the short fiber material is impregnated with the fluororesin to which the powder of fluorinated pitch is added, and the mixture is subjected to heat treatment and / or radiation irradiation treatment. Provided is a method for producing a crosslinked fluororesin composite material, which comprises cross-linking a fluororesin and chemically reacting a fluorinated pitch with a fluororesin.

Further, according to the present invention, the surface of the metal member is coated with fluororesin to which powder of fluorinated pitch is added, and then the fluororesin is subjected to heat treatment and / or radiation irradiation treatment. There is provided a method for producing a composite member, characterized in that fluorinated pitch and a fluororesin are chemically reacted with each other while the fluororesin coating and the metal member are firmly bonded together.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Specific embodiments of a crosslinked fluororesin composite material, a composite member, and a method for producing them according to the present invention will be described below.

In the step of adding fluorinated pitch to a fluororesin such as polytetrafluoroethylene resin or tetrafluoroethylene-based copolymer resin, the fluorinated pitch powder is added to a dispersion liquid in which the fluororesin powder is uniformly dispersed. It is carried out by adding and mixing. The liquid for efficiently dispersing the powder, that is, the dispersion medium, is water and an emulsifier, water and an alcohol,
A mixed solvent of water and acetone or a mixture of water, alcohol and acetone can be selected and prepared by those skilled in the art. Alternatively, without using the dispersion liquid, powder of fluorinated pitch may be added to and mixed with fine powder of fluororesin. The amount of the fluorinated pitch powder added is preferably 0.05 to 50% by weight with respect to the amount of the fluororesin. 0.0
If it is less than 5% by weight, the cross-linking density of the network structure in which the fluorinated pitch and the fluororesin react to form a molecular composite becomes low, and the disadvantages of the fluororesin, such as low toughness, creep properties and abrasion properties, are not sufficiently improved. . On the other hand, if it exceeds 50% by weight, the crosslink density becomes large, and it becomes hard and brittle, so that the original characteristics of the fluororesin are lost.

The fluorinated pitch powder used in the present invention has an average molecular weight of about 2000 to 3000 and an average particle size of about 1.2 microns. Its softening temperature is about 270 ° C., and it begins to decompose at 300 ° C. or higher. Fluorinated pitch is obtained by replacing hydrogen in coal tar with fluorine in fluorine gas. Such fluorinated pitch powder is commercially available from Osaka Gas Chemicals Co., Ltd. under the trade name of Linoves P (registered trademark).

In the step of impregnating the continuous resin material or the short fiber material with the fluororesin, the fiber is dipped in the dispersion liquid of the fluororesin to which the fluorinated pitch is added as described above, or the dispersion liquid is applied to the fiber. It is done by Although the materials used as the fiber material are as described above,
It is possible to use all fibers that have heat resistance of 0 ° C. or higher and that are used in conventional fiber reinforced plastics. The reason why the heat resistance of 150 ° C. or higher is necessary is to prevent the strength of the fiber from being lowered by the heat treatment performed when reacting the fluorinated pitch and the fluororesin.

The step of coating the surface of the metal member with the fluororesin is carried out by coating the surface of the metal member with a dispersion liquid of the fluororesin to which fluorinated pitch has been added, or by spraying it uniformly. The material used as the metal member is as described above, but any metal having a melting point of 150 ° C. or higher can be used.

Thus, the dispersion medium is removed by air-drying or hot-air-drying the mixed dispersion solution, a powder obtained by mixing the fluororesin and the fluorinated pitch, or a mixture of the fluororesin and the fiber is formed into an arbitrary shape. Or a fluorocarbon resin coated on the surface of a metal member is heat-treated at a temperature range of 120 to 400 ° C., preferably 270 to 360 ° C. which is higher than the softening point of fluorinated pitch. As a result, the fluororesin is crosslinked, and the fluoropitch and the fluororesin are thermochemically reacted to be crosslinked. That is, the fluorinated pitch uniformly dispersed in the fluororesin is bound to the fluororesin by a covalent bond, and the fluororesin itself is also bound by a covalent bond via radicals induced by the fluorinated pitch. Therefore, it is possible to obtain a composite material having a network structure that is crosslinked in a molecular composite manner, or a composite member in which the composite material and the metal member are firmly bonded. When the heating temperature exceeds 400 ° C., thermal decomposition of the fluororesin proceeds, which is not preferable. Further, when the heating temperature is lower than 120 ° C., decomposition of fluorinated pitch does not occur and reaction with the fluororesin does not occur. As a heating means, an indirect or direct heat source such as a normal gas circulation type constant temperature bath, an infrared heater or a panel heater can be used. Alternatively, the molding and the heat treatment may be carried out at the same time by using a hot press molding machine.

Further, the above-mentioned molded body is subjected to a temperature range of room temperature to 400 ° C. in an atmosphere of oxygen concentration of 0 to 200 torr, preferably 270 to 360 ° C. which is higher than the softening point of fluorinated pitch.
By irradiating radiation with an irradiation dose of 0.1 kGy to 10 MGy while maintaining the temperature range of 1, the composite material or the composite member having the same network structure as described above can be obtained. According to this method, a higher mesh density can be obtained. 0-20
The atmosphere having an oxygen concentration of 0 torr refers to an atmosphere in which the oxygen concentration is controlled to 200 torr or less by replacing oxygen in the atmosphere with an inert gas such as helium or nitrogen in addition to vacuum. By using such an atmosphere, oxidative decomposition of the fluororesin is prevented from occurring without suppressing the crosslinking reaction of the fluororesin during irradiation. Oxygen concentration is 20
If it exceeds 0 torr, radicals induced by radiation preferentially bond with oxygen, and the crosslinking reaction is significantly suppressed. If the irradiation dose is less than 0.1 kGy, the concentration of radicals that contribute to the reaction will be low, and the properties of the resulting composite material will not be sufficiently improved. On the other hand, if it exceeds 10 MGy, the crosslink density becomes large, and it becomes hard and brittle, and the material properties preferable as a fluororesin are lost. As the radiation, ionizing radiation such as an electron beam, an X-ray, a neutron beam, and a high-energy ion is used, and any one of them may be used alone or in combination. As the heating means for controlling the temperature, an indirect or direct heat source such as a normal gas circulation type constant temperature bath, an infrared heater or a panel heater can be used. Alternatively, the heat generated by controlling the energy of the radiation generated from the electron accelerator or the ion accelerator may be used as it is as a heat source.

The network density of the crosslinked fluororesin in the composite material or composite member thus obtained can be arbitrarily adjusted by controlling the addition amount of fluorinated pitch, the heating temperature, or the radiation irradiation dose.

In the fluororesin composite material of the present invention,
The toughness, wear and creep deformation under sliding environment, and radiation resistance have been remarkably improved as compared with conventional fluororesins.
The reason is considered as follows. Regarding radiation resistance: When the fluorinated pitch and the fluororesin are cross-linked by a chemical reaction to form a molecular complex, the ionization potential at the cross-linking point in the molecule is lowered, and the energy absorption of radiation is relaxed at the cross-linking site. Therefore, resistance to radiation is improved. In particular, fluorinated pitch has an aromatic ring in the molecule, and the material having this aromatic ring and the fluororesin are chemically bonded to each other to form a network structure, so that the radiation resistance is easily improved. Toughness: Fluororesin, especially polytetrafluoroethylene, is a rigid molecule and has low interaction between molecular chains. Therefore, depending on the cross-linking of the fluororesin alone, the rigidity and the low interactivity between the molecular chains become unfavorable, and the characteristics such as easy cracking and bridging even when cross-linked appear. According to the present invention, the drawbacks of the fluororesin are structurally alleviated by forming a molecular composite of the fluorinated pitch and the fluororesin, and the material is changed to a very tenacious material. Abrasion resistance: Fluororesin has a low interaction between molecular chains, so the group of molecular chains is easily desorbed, but the interaction between molecular chains is enhanced by the formation of a network structure, Detachment of molecular chain groups due to friction is prevented, and abrasion is less likely to occur. Creep deformation: By forming a network structure, slippage between molecular chains due to low interaction between molecular chains is suppressed, and creep deformation resistance is improved.

[0020]

EXAMPLES The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples, and various modifications, improvements, combinations and the like that can be easily conceived by those skilled in the art are also within the scope of the present invention.

Example 1 60 parts of fine powder of polytetrafluoroethylene (hereinafter referred to as PTFE) having an average particle diameter of 0.25 μm and 100 parts of a dispersion medium composed of water and an emulsifier (weight part, the same applies hereinafter) and fluorinated. A liquid was prepared by uniformly dispersing 5 parts of pitch powder (Rinoveth P, manufactured by Osaka Gas Chemicals Co., Ltd., hereinafter referred to as FP). The PTFE / FP blend obtained by drying this liquid is fired for 15 minutes in a nitrogen stream at 350 ° C. which is higher than the crystal melting point of PTFE,
It was formed into a sheet having a thickness of 0.2 mm. The thermal characteristics of this molded sheet and a commercially available PTFE sheet (manufactured by Nichias Co., Ltd., thickness: 0.2 mm) were measured by a differential scanning calorimeter (DSC).
Was analyzed using. The results obtained are shown in Table 1,
In the blended molded sheet, lower crystallization temperature and lower crystalline melting point were observed as compared with the commercially available PTFE sheet.

[0022]

[Table 1]

Example 2 A tear test was conducted on the PTFE / FP blend molded sheet of Example 1 and a commercially available PTFE sheet. This tear test is performed by making a 2 cm cut from the edge in the center of the short side of a sheet with a short side of 4 cm and a long side of 10 cm, gripping both sides of the cut with a chuck, and tearing at a crosshead speed of 100 cm / min. It is a measure of strength. The obtained results are shown in Table 2,
The tear strength of the blend molded sheet is significantly higher than the commercially available PTFE sheet.

[0024]

[Table 2]

Example 3 With respect to the PTFE / FP blend molded sheet of Example 1 and a commercially available PTFE sheet, the friction coefficient and wear coefficient were measured. For the test, a thrust type friction wear tester is used, and according to JIS K7218, a cylindrical ring made of S45C (outer diameter 25.6 mm, inner diameter 20.6 mm) is pressed against the test sheet at a pressure of 20 kgf / cm ^2. , The ring was rotated at a speed of 10 m / min. The results obtained are shown in Table 3,
The blended molded sheet has a low coefficient of friction that confirms good lubricity and has excellent wear resistance.

[0026]

[Table 3]

Example 4 The PTFE / FP blend molded sheet of Example 1 and a commercially available PTFE sheet were heated to 340 ° C. in an argon stream and irradiated with an electron beam of 2 MeV at 300 kGy and 500 kGy to be crosslinked. Thermal characteristics were analyzed using DSC for each. The obtained results are shown in Table 4, and it was observed that the blended molded sheet had a lower melting temperature and a lower crystallization temperature, and a lowering of the crystallization heat amount as compared with the commercially available PTFE sheet.

[0028]

[Table 4]

Example 5 PTFE / FP crosslinked by irradiation with 300 kGy in Example 4
The same tear test as in Example 2 was performed on the blend molded sheet and the commercially available PTFE sheet. The obtained results are shown in Table 5, and the tear strength of the blend molded sheet is significantly higher than that of the commercially available PTFE sheet.

[0030]

[Table 5]

Example 6 55 parts of PTFE fine powder having an average particle diameter of 0.5 μm and F based on 100 parts of a dispersion medium composed of water and an emulsifier.
A liquid in which 15 parts of P was uniformly dispersed was prepared. The PTFE / FP blend obtained by drying this liquid is PTFE
Was fired for 30 minutes in a nitrogen stream at a temperature of 300 ° C. or higher, which is higher than the crystal melting point, to form a sheet having a thickness of 0.3 mm. This molded sheet and a commercially available PTFE sheet (Asahi Glass Co., Ltd.)
Manufactured by Fluoropolymers (registered trademark, thickness: 0.3 mm) was analyzed for thermal characteristics by DSC. The results obtained are shown in Table 6.
In the blended molded sheet, commercially available P
A decrease in the heat of crystallization and a decrease in the melting point of the crystal were observed as compared with the TFE sheet.

[0032]

[Table 6]

Example 7 With respect to the PTFE / FP blend molded sheet of Example 6 and the commercially available PTFE sheet, the same friction coefficient and wear coefficient as in Example 3 were measured. The results obtained are shown in Table 7, and the blended molded sheet has a low coefficient of friction that supports good lubricity and has excellent wear resistance.

[0034]

[Table 7]

Example 8 The PTFE / FP blend molded sheet of Example 6 and a commercially available PTFE sheet were heated to 340 ° C. in a helium gas stream and irradiated with an electron beam of 2 MeV at 100 kGy and 300 kGy to be crosslinked. Thermal characteristics were analyzed using DSC for each. The obtained results are shown in Table 8, and it was observed that the blended molded sheet had a lower melting temperature and a lower crystallization temperature, and a lowering of the crystallization heat amount as compared with the commercially available PTFE sheet.

[0036]

[Table 8]

Example 9 A liquid was prepared by uniformly dispersing 50 parts of fine powder of PTFE having an average particle diameter of 0.2 μm and 10 parts of FP in 100 parts of a dispersion medium composed of water and an emulsifier. To this liquid, carbon fiber woven cloth (Toray Industries, Inc., trading card T-300
An operation of dipping one sheet (registered trademark)) and drying was repeated 6 times to prepare a sheet in which 100 parts of the carbon fiber woven cloth was impregnated with 100 parts of the PTFE / FP blend powder. Six sheets were laminated and fired for 15 minutes in a nitrogen stream at 340 ° C., which is higher than the crystal melting point of PTFE, to form a plate (thickness 1.4 mm). For comparison, a laminate made of only carbon fiber woven fabric and PTFE fine powder was also molded under the same manufacturing conditions. A three-point bending test was performed on both of the molded plates at a fulcrum distance of 50 mm and a crosshead speed of 1 mm / min. The obtained results are shown in Table 9, and the carbon fiber-reinforced PTFE / FP composite sheet showed significantly higher strength than the carbon fiber-reinforced PTFE sheet.

[0038]

[Table 9]

Example 10 Each of the carbon fiber reinforced PTFE / FP composite sheet and the carbon fiber reinforced PTFE sheet of Example 10 was heated to 340 ° C.
The mixture was transferred to an irradiation container heated in a nitrogen atmosphere and irradiated with an electron beam of 2 MeV at 500 kGy for crosslinking. The same three-point bending test as in Example 9 was performed on each sheet. The obtained results are shown in Table 10, and carbon fiber reinforced PTF
High strength was shown in the E / FP composite sheet.

[0040]

[Table 10]

Example 11 A liquid was prepared by uniformly dispersing 60 parts of PTFE fine powder having an average particle size of 0.25 μm and 5 parts of FP in 100 parts of a dispersion medium composed of water and an emulsifier. This liquid is 10 cm square and 2 mm thick stainless steel (SUS30
After being applied to the surface of 4) and air-dried at 50 ° C., it was baked in air at 330 ° C. above the crystalline melting point of PTFE for 10 minutes, whereby a coating with a thickness of 20 μm was applied. For comparison, a coating material coated only with PTFE fine powder was also produced under the same manufacturing conditions. A peeling test was performed on each coating material. In this peel test, 100 squares were made by putting lines on the coated surface of 10 cm square with a cutter knife at 1 cm intervals in the vertical and horizontal directions, immersed in cold water at 0 ° C for 5 minutes, and in boiling water at 100 ° C for 5 minutes. After soaking, use adhesive tape at room temperature for 10
It was tested how many of 0 squares would peel off. The obtained results are as shown in Table 11, and PTFE /
The peel strength of the coating material for the FP blend was extremely high.

[0042]

[Table 11]

Example 12 PTFE / FP blend body coating material and PT of Example 11
Each of the FE coating materials was transferred to an irradiation container in a nitrogen atmosphere heated to 340 ° C. and irradiated with an electron beam of 250 keV by 100 kGy to be crosslinked. A peeling test similar to that in Example 11 was performed on each coating material. The results obtained are shown in Table 1.
2 and the blend coating material showed high strength.

[0044]

[Table 12]

[0045]

As described above, the crosslinked fluororesin composite material according to the present invention has high heat resistance, chemical resistance, water repellency, antifouling property, lubricity, etc. which are characteristics of conventional fluororesins. Not only is it a material that is excellent in radiation resistance, wear resistance, tear strength, and bending strength. Therefore, the application of fluororesin is greatly expanded. The composite member coated with the crosslinked fluororesin composite material has a very high adhesive strength between the base material and the coating, and is a highly reliable composite member having the above-mentioned characteristics.

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) C08L 27/18 C08L 27/18 C09D 127/12 C09D 127/12 127/18 127/18 (72) Inventor Hoichi Washio 4-31-17 Kamoi, Midori-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Chie Udagawa 1-10-17 Nanyodai, Yoshii-cho, Tano-gun, Gunma Prefecture (72) Inventor Yoneho Tabata 5-32, Kasuga-cho, Nerima-ku, Tokyo 1 Hills Nerima Kasugacho 601 F Term (reference) 4F070 AA24 AC04 AC06 AC17 AC22 AC28 AC79 AC90 AD02 AE08 BA02 BB08 GA04 GA06 GB02 GB03 HA04 HB01 HB02 4F072 AA02 AA04 AA08 AB04 AB06 AB08 AB09 AB10 AB11 AD21 AD55 AG16 A12 AD05 AD16 AG16 AD02 AD55 AG03 A02 AD55 AD03 A15 AD15 AD03 BD152 CL062 DA017 DA067 DD006 DJ007 DL007 FA042 FA047 4J038 CD091 CD121 CD122 DJ022 HA026 HA166 HA436 HA486 JA11 JA13 KA08 KA19 NA05 NA11 NA14 PA19

Claims (13)

[Claims] 1. A fluororesin composite material in which fluororesin is crosslinked by subjecting fluororesin to which fluoropowder powder is added to heat treatment and / or radiation irradiation treatment, wherein fluoropitch is chemically combined with fluororesin. A crosslinked fluororesin composite material having a network structure in which a molecule is compounded by a reaction. 2. The crosslinked fluororesin composite material according to claim 1, wherein the fluororesin is a polytetrafluoroethylene resin or a tetrafluoroethylene-based copolymer resin. 3. The crosslinked fluororesin composite material according to claim 1, wherein the amount of the fluorinated pitch powder added is 0.05 to 50% by weight with respect to the amount of the fluororesin. 4. A composite material in which a fluororesin is fiber-reinforced by mixing with a continuous fiber material or a short fiber material,
Powder of fluorinated pitch is added to the fluororesin, and the fluororesin is subjected to a heat treatment and / or a radiation irradiation treatment to crosslink, and the fluorinated pitch chemically reacts with the fluororesin. A crosslinked fluororesin composite material having a network structure of molecular composite. 5. The continuous fiber material or the short fiber material,
One or more selected from PTFE fiber, glass fiber, carbon fiber, silicon carbide fiber, silicon nitride fiber, aramid fiber, PBO fiber, and metal fiber,
The composite material according to claim 4. 6. A composite member, wherein the surface of the metal member is coated with the crosslinked fluororesin composite material according to claim 1. 7. The fluororesin to which the powder of fluorinated pitch is added is subjected to heat treatment and / or irradiation treatment to crosslink the fluororesin and chemically react the fluorinated pitch with the fluororesin. A method for producing a crosslinked fluororesin composite material. 8. A continuous resin material or a short fiber material is impregnated with a fluororesin to which powder of fluorinated pitch is added, and the mixture is subjected to heat treatment and / or irradiation treatment to crosslink the fluororesin. A method for producing a crosslinked fluororesin composite material, which comprises chemically reacting fluorinated pitch with a fluororesin. 9. The method for producing a crosslinked fluororesin composite material according to claim 7, wherein the heat treatment is performed in a temperature range of 120 to 400 ° C. 10. The radiation irradiation process is 0 to 200 torr
The method for producing a crosslinked fluororesin composite material according to claim 7 or 8, which is carried out in a temperature range of room temperature to 400 ° C in an atmosphere of oxygen concentration of, and the irradiation dose of radiation is 0.1 kGy to 10 MGy. 11. A fluororesin to which a powder of fluorinated pitch is added is coated on the surface of a metal member, and then the fluororesin is subjected to heat treatment and / or radiation irradiation treatment to crosslink the fluororesin and A method for producing a composite member, which comprises chemically reacting a chemical conversion pitch with a fluororesin, and at the same time, firmly adhering a fluororesin coating and a metal member. 12. The method for manufacturing a composite member according to claim 11, wherein the heat treatment is performed in a temperature range of 120 to 400 ° C. 13. The radiation irradiation process is 0 to 200 torr.
12. The method for producing a composite member according to claim 11, wherein the method is carried out in a temperature range from room temperature to 400 ° C. in an atmosphere of oxygen concentration, and the irradiation dose of radiation is 0.1 kGy to 10 MGy.