JPS6245066B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for manufacturing a composite body in which a molded member made of fluororesin (hereinafter referred to as fluororesin member) and a member to be worn made of a material with better heat resistance than the fluororesin constituting the member are bonded and integrated. It is related to. Fluorine materials are widely used because they have various excellent properties such as electrical properties, thermal properties, and chemical resistance, but they are not only expensive but also have inert surfaces that make them difficult to use for other materials. It has the disadvantage that it is difficult to obtain a complex with For this reason, in the prior art, the surface is adhesively treated using a chemical such as a liquid ammonia solution of an alkali metal, and other members are adhered to this treated surface via an adhesive to form a composite. However, in this conventional technology, since alkali metals are used, there is a high risk of inducing a fire during treatment, there are problems in handling the used treatment liquid, and the adhesive treated surface of the fluorine material is brown. This reduces the product value and also reduces the surface electrical resistance.Furthermore, if the adhesive-treated surface is exposed to ultraviolet rays or left in high temperatures, the treatment effect (surface adhesion) will decrease significantly. It had the disadvantage of being stored away. Furthermore, since the properties of the resulting composite depend on the heat resistance, chemical resistance, weather resistance, etc. of the adhesive, there is also the drawback that the excellent properties of the fluorine material cannot be fully utilized. Furthermore, there is a method of bringing a fluorine material member and a member to be worn into contact and applying heat and pressure to integrate the two members. In order to integrate both parts, it is necessary to heat the parts to a temperature much higher than the melting point of the fluororesin. In addition, if the fluorine resin member is thin, it tends to flow due to the high temperature during heating, and as a result, the thickness of the fluorine resin component in the resulting composite may become uneven. In view of the above-mentioned current situation, the inventors of the present invention have conducted intensive studies and found that
By sputter etching a predetermined surface of a fluorocarbon resin material under specific conditions, and heating the material by bringing it into contact with the treated surface, it is possible to perform sputter etching in the relatively low temperature range from the softening point to the melting point of the fluorocarbon resin. It was also discovered that both parts can be strongly bonded and integrated, and that by setting the heating temperature above the melting point of the fluororesin, both parts can be bonded and integrated much more firmly than when no sputter etching treatment is applied. This is what we have come to complete. That is, in the method for manufacturing a composite according to the present invention, a predetermined surface of a fluororesin molded member is heated to an atmospheric pressure of 0.0005 to
After sputter etching treatment under the condition of 0.5 Torr, the sputter etching treated surface of the molded member is brought into contact with a member made of a material having better heat resistance than the fluorine resin and heated. This method is characterized by softening or melting the molded member and bonding and integrating the fluororesin molded member and the member to be worn. The fluorine material used in the present invention is polytetrafluoroethylene (hereinafter referred to as PTFE),
Tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter referred to as FEP), ethylene-tetrafluoroethylene copolymer, perfluoro(alkyl vinyl ether) copolymer represented by the following general formula (hereinafter referred to as PFA)

[Formula] However, Rf represents a fluorinated alkyl group.It is obtained by molding a fluororesin such as polyvinyl fluoride into a predetermined shape such as a film, block, rod, or tube.
Preferably, it is made of PFA. This fluorine material is made by mixing a predetermined amount of pigments for coloring and various additives such as carbon black, graphite, silica powder, asbestos powder, glass powder, etc. to improve wear resistance in fluororesin. It may be something that has been done. In the present invention, the atmospheric pressure when sputter etching the fluorine material is as described above at room temperature.
0.0005~0.5Torr, preferably 0.001~
It is 0.15Torr. Below 0.0005 Torr, the discharge that performs spatter etching is not sustained, and
This is because if the temperature exceeds 0.5 Torr, the etching rate will drop significantly and the discharge itself will become unstable. Furthermore, other sputter etching processing conditions include the normal frequency of several hundred KHz to several + MHz, the practically allocated frequency for industrial use of 13.56 MHz, and the discharge power of 0.1 to several + MHz.
It is 5.0Watt/ ^cm2 . The lower the discharge power, the longer the treatment time needs to be, so in practice it is better to increase the discharge power and reduce the treatment time (the degree of surface treatment is approximately expressed as the product of the discharge power and the treatment time). ). In the present invention, in order to perform sufficient sputter etching treatment on the surface of the fluorine member in a short time,
The product of discharge power (Watt/cm ² ) and processing time (sec) is about 0.1 to 200 Watt・sec/cm ² Preferably about 1 to
It is best to set the discharge power and processing time to 100Watt·sec/cm ² . In addition, the required minimum distance between electrodes is approximately 1/√(P
is proportional to the pressure Torr), for example, the atmospheric pressure
At 0.005 Torr, it is 30 mm or more. All gases can be used as the atmospheric gas, but extremely active gases such as chlorine gas and fluorine gas, as well as organic gases that undergo discharge polymerization during sputter etching, should be avoided for the safety of the apparatus. In practice, inert gas such as argon, air, water vapor, carbon dioxide, etc. are used. Next, an example of an apparatus for sputter etching a fluorine member will be explained with reference to FIG. Reference numeral 1 denotes an exhaust pipe connected to a vacuum pump (not shown) for exhausting gas in the reduced pressure vessel 2, 3 a valve for introducing atmospheric gas into the reduced pressure vessel 2, and 4 a fluorine member 5 for spacing. It is an electrode for vine etching, and is electrically insulated from the vacuum container 2 and connected to the external matching box 6 using a hermetically sealed lead wire.
(impedance matching device), and further led to a high frequency power source 7. 8 is a shielding electrode for electrode 4, and a high frequency power source 7
It is electrically connected to the ground side of the Reference numeral 9 denotes a counter electrode, which is also connected to the ground side of the high frequency power source 7. The reduced pressure container 2 serves to keep the atmospheric pressure constant, and if a metal reduced pressure container is used, it is connected to the ground side of the high frequency power source 7. The matching box 6 is a circuit consisting of capacitance and inductance, and is used to perform impedance matching. Next, to explain the outline of the sputter etching process principle, when the potential on the electrode 4 side is negative with respect to the counter electrode 9, positive ions generated as a result of discharge are accelerated and collide with the surface of the fluorine member 5. Then, sputter etching is performed. At this time, the fluorine member 5
The positive charges of the colliding positive ions accumulate on the surface of the , increasing the surface potential.
The potential difference between this surface and the counter electrode 9 becomes small, making it difficult to maintain discharge. However, in the next half cycle of the high-frequency voltage, the potential on the electrode 4 side becomes positive with respect to the counter electrode 9, so electrons enter the surface of the fluorine member 5 from the discharge space, and due to the negative charge that the electrons have, Neutralizes positive ions that have accumulated on the surface. As a result, when the potential on the electrode 4 side becomes negative with respect to the counter electrode 9 in the next half cycle of the high frequency voltage, the potential difference between the two is large and discharge occurs, and the generated positive ions are accelerated. It collides with the surface of the fluorine member 5 to enable sputter etching. The above steps are repeated for each cycle of the high frequency voltage, and the surface of the fluorine member 5 is sputter etched. In order to continuously perform the sputter etching process on the surface of a fluorocarbon material, it is sufficient to install a fluorocarbon material moving device in a reduced pressure container. , a supply roll 10 and a take-up roll 11 are placed in a vacuum container 2.
The sheet-like fluorine material 51 is fed out from the supply roll 10 at a predetermined speed while sputter etching is performed, and then wound onto the take-up roll 11. The fluorine member treated by the above sputter etching process is then coated with a material having a higher softening point, a higher melting point, or an infusibility and better heat resistance than the fluororesin constituting the fluorine member. For example, members made of metal, ceramic, glass, polyimide, paper, etc. are placed in contact with each other and heated to firmly bond and integrate the two members. The reason why the adhesion between the fluorocarbon material and the adhered material becomes strong is not necessarily clear, but the sputter etching process lowers the molecular weight of the fluorocarbon resin on the surface of the fluorocarbon material, making it easier to thermally flow. At the same time, a functional group that can contribute to adhesion is generated, and it is inferred that the main reason is that this thermofluidity and the adhesive ability of the generated functional group act synergistically. According to the present invention, even if the temperature in the heating process is within the relatively low temperature range of the softening point or melting point of the fluororesin constituting the fluororesin member, the fluororesin member and the member to be worn are firmly bonded and integrated. be able to. This heating temperature may be set higher than the melting point of the fluororesin, if desired. The time required for heating in this step is determined depending on the heating temperature, the size of the fluorine member, etc., and is usually about 2 to 100 minutes. In addition, in this process, in order to further strengthen the degree of adhesion between the fluorine material member and the adhered member, approximately 1~
It is preferable to work while applying a pressure of about 100 kg/cm ² . Furthermore, in the invention, when a particularly high degree of adhesion between the fluorine member and the member to be worn is desired,
The surface of the member to be worn can be subjected to roughening treatment, oxidation treatment, etc. in advance before use. The present invention is configured as described above, and can firmly bond and integrate a fluorine member and a member to be worn even in the relatively low temperature range of the softening point or melting point of the fluororesin constituting the fluororesin member. The degree of adhesion can be further improved by setting the temperature above the melting point, and since there is no adhesive between the two components, the resulting composite has features such as being able to fully demonstrate the performance of fluorine components. . Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 100μ thick FEP film (melting point 285-290℃)
is placed in the vacuum container 2 of ^the sputter etching processing apparatus shown in FIG. is introduced to adjust and maintain the atmospheric pressure in the vacuum vessel 2 at 2×10 ⁻³ Torr. Note that the distance between the electrodes was 110 mm, and the ambient temperature was 20±2°C. Next, a high frequency voltage of 13.56MHz was applied, the discharge power was adjusted to 1Watt/ ^cm2 , and spatter etching was performed for 15 seconds.The power was then turned off and air was introduced from the valve 3 into the vacuum vessel 2. was introduced to return to normal pressure, and one side was treated with sputter etching.
Obtain FEP film. Next, a 0.6 mm thick aluminum plate was placed on the sputter etched surface of this FEP film, and heated for 10 minutes under a pressure of 7.2 kg/cm ² using a hydraulic press equipped with a hot plate kept at 300°C. After pressing, the mixture was cooled to obtain a plate-shaped composite (sample number 1). On the other hand, apart from this, the atmospheric pressure in the sputter etching process and the temperature in the heating process are
Complexes of sample numbers 2 to 6 were obtained in the same manner as sample number 1 except for the settings shown in the table. The adhesive strength between FEP film and aluminum plate in these composites was measured at a temperature of 25 ± 2℃ and a tensile speed.
Table 1 also shows the results measured by the 180° peeling method at 50 mm/min. For comparison, the atmospheric pressure in the sputter etching process was set to 1×10 -5 Torr and 1×10 ^-5 Torr, respectively.
The data for the composites of samples No. 7 to 10 were obtained by performing all the same operations as for sample No. 1 except for setting the temperature to 1 Torr, and the data obtained by bonding and integrating the above FEP film with an aluminum plate without sputter etching. The data for the complex of sample number 11 are also shown.

[Table] As is clear from Table 1 above, the composite obtained by the present invention can be used both when the temperature in the heating process is in the low temperature range of the softening point or melting point of the fluororesin or in the high temperature range above the melting point. It can be seen that both members are firmly bonded and integrated. Example 2 When sputter etching the FEP film of Example 1 using the apparatus shown in Figure 1, the atmospheric pressure was set to 2 x 10 ^-2 Torr, and the discharge power and processing time were set as shown in Table 2. A treated film was obtained, and then the treated film and the aluminum plate were bonded together in the same manner as in the case of Sample No. 4 to obtain composites of Sample Nos. 12 to 14. Table 2 shows the measurement results of the adhesive strength between the FEP film and the aluminum plate in these composites.

[Table] Example 3 PTFE film and PFA each with a thickness of 100μ
Using a film, a sputter etching process and a heating process were carried out at an atmospheric pressure of 2 x 10 ^-2 Torr and other conditions as shown in Table 3. Sample numbers 15 (with PTFE) and 16 (with PFA) consisting of plates
Two composites were obtained. Table 3 also shows the measurement results of the adhesive strength between the film and the aluminum plate in these composites. For comparison, the above PTFE film and
Sample No. 17 obtained by adhering PFA film to aluminum plate without sputter etching treatment
Data for two composites (using PTFE) and 18 (using PFA) are shown simultaneously.

【table】 [Brief explanation of the drawing]

FIGS. 1 and 2 are schematic diagrams showing an example of an apparatus used for sputter etching a predetermined surface of a fluororesin molded member according to the present invention. 2...Reduced pressure container, 4...Electrode, 5...Fluororesin molded member, 6...Matching box, 7...
...High frequency power supply, 8... Shielding electrode, 9... Counter electrode.

Claims (1)

[Claims] 1. Apply atmospheric pressure to the specified surface of the fluororesin molded member.
After performing sputter etching treatment under conditions of 0.0005 to 0.5 Torr, the sputter etching treated surface of the molded member is brought into contact with a member to be adhered made of a material with better heat resistance than the fluororesin and heated. . A method for producing a composite body, which comprises softening or melting the molded member and bonding and integrating the fluororesin molded member and the member to be worn.