JP5349923B2 - Microwave plasma processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave plasma processing device which easily applies a prescribed treatment on the outer circumference of a processing object. <P>SOLUTION: The microwave plasma processing device 1 is provided with: a tubular inner circumference wall part 30 having a slit 300; a tubular outer circumference wall part 31 arranged at the outside in axial direction of the inner circumference wall part 30; a wave-guiding passage 33 demarcated between the inner circumference wall part 30 and the outer circumference wall part 31; an irradiation part 34 which is demarcated inside in axial direction of the inner circumference wall part 30, is communicated with the wave-guiding passage 33 through the slit 300, and in which the outer circumference face 800 of the processing object 80 is arranged; and a gas supply tube 35 which supplies a plasma generating gas to the slit 300. In a nearly atmospheric pressure condition, microwave and the plasma generating gas are made to pass through the slit 300 and a high electric field is formed in the vicinity of the slit 300 to generate plasma in the irradiation part 34, and thereby a prescribed treatment is applied on the outer circumference face 800 by the plasma. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a microwave plasma processing apparatus for generating a plasma by microwaves under a substantially atmospheric pressure condition and performing a predetermined process on a processing object by the plasma.

  In the automobile industry, a fuel pipe member having a multilayer structure having a barrier layer made of a fluororesin and a reinforcing layer made of a polyamide resin has been developed. The reinforcing layer is laminated on the radially outer side of the barrier layer. The barrier layer suppresses the evaporation of fuel from the fuel piping member. The reinforcing layer ensures the strength of the fuel piping member.

  Fluorine resin and polyamide resin do not melt and bond. Therefore, conventionally, in order to improve the adhesion between the barrier layer and the reinforcing layer, a surface modification treatment by corona discharge has been performed on the outer peripheral surface of the barrier layer (Patent Document 1). Moreover, the fluorine-type resin of the barrier layer was acid-modified (grafted) (Patent Document 2). Further, the outer surface of the barrier layer has been subjected to surface modification treatment with reduced-pressure radio frequency (RF) plasma (Patent Document 3).

However, as described in Patent Document 1, it is necessary to apply a relatively large bias when the surface modification treatment of the outer peripheral surface of the barrier layer is performed by corona discharge. For this reason, an excessive charge may be locally applied. In this case, the outer peripheral surface of the barrier layer tends to be rough due to abnormal discharge. Moreover, as described in Patent Document 2, when the fluorine-based resin of the barrier layer is acid-modified, the manufacturing cost of the fuel piping member is increased. In addition, as described in Patent Document 3, when the surface modification treatment of the outer peripheral surface of the barrier layer is performed by a low-pressure radio frequency (RF) plasma treatment, it is necessary to ensure a pressure lower than the atmospheric pressure. For this reason, a vacuum facility etc. are needed. Therefore, the equipment cost of the plasma processing apparatus, and thus the manufacturing cost of the fuel piping member will increase.
Japanese Patent Publication No.8-5167 Japanese Patent Laid-Open No. 11-320770 JP 2001-270051 A JP 2007-299720 A

  Patent Document 4 discloses a plasma processing apparatus that can generate plasma under substantially atmospheric pressure conditions. The plasma processing apparatus described in the document includes a dielectric substrate, a microstrip line, a ground conductor, and a dielectric gas pipe. The microstrip line and the ground conductor are disposed on both sides of the dielectric substrate. A microwave is input from one end of the dielectric substrate. The other end of the dielectric substrate is disposed near the nozzle of the dielectric gas pipe. The microwave propagated through the dielectric substrate is radiated near the nozzle of the dielectric gas pipe. An electric field is formed near the nozzle of the dielectric gas pipe by the microwave. On the other hand, gas flows in the dielectric gas pipe. Plasma is generated by ionizing the gas in the microwave electric field. The generated plasma is blown out from the nozzle of the dielectric gas pipe. By irradiating the plasma, the surface modification treatment of the processing object is performed. According to the plasma processing apparatus described in this document, the surface modification treatment can be performed at atmospheric pressure or a pressure near atmospheric pressure. For this reason, vacuum equipment is unnecessary.

  However, in the case of the plasma processing apparatus described in this document, the direction of plasma irradiation is one direction. For this reason, according to the plasma processing apparatus described in the document, it is not possible to irradiate the processing target with plasma from a plurality of directions. Accordingly, when the outer peripheral surface of the cylindrical or columnar processing target is the processing target surface, it is difficult to perform the surface modification process.

  The microwave plasma processing apparatus of the present invention has been completed in view of the above problems. Therefore, an object of the present invention is to provide a microwave plasma processing apparatus that can easily perform a predetermined process on the outer peripheral surface of a cylindrical or columnar processing object.

(1) In order to solve the above-described problem, a microwave plasma processing apparatus of the present invention includes a cylindrical inner peripheral wall portion having a slit and a cylindrical outer peripheral wall portion arranged on the axially outer side of the inner peripheral wall portion. And a waveguide path that is defined between the inner peripheral wall part and the outer peripheral wall part and that propagates microwaves, and is defined on the inner side in the axial direction of the inner peripheral wall part, and passes through the slit to the waveguide path. An irradiating portion in which the outer peripheral surface of the cylindrical or columnar processing object is disposed, and a gas supply pipe for supplying the plasma generating gas directly or indirectly to the slit are provided. Under atmospheric pressure conditions, the microwave and the plasma generating gas are passed through the slit to concentrate the electric field of the microwave to form a high electric field near the slit, and the high electric field is used to generate the plasma. Gas is ionized and plasma is applied to the irradiated part Generated by the plasma you characterized by applying predetermined processing to the external peripheral surface of the processing object.

  According to the microwave plasma processing apparatus of the present invention, the waveguide path → the slit → the irradiation portion is arranged from the outside in the axial direction to the inside in the axial direction. Moreover, the outer peripheral surface of the cylindrical or columnar processing object is arrange | positioned at the irradiation part. For this reason, the plasma is applied to the outer peripheral surface of the processing object from the outside in the axial direction toward the inside in the axial direction. Therefore, according to the microwave plasma processing apparatus of the present invention, it is easy to perform predetermined processing on the outer peripheral surface of the cylindrical or columnar processing target. Further, according to the microwave plasma processing apparatus of the present invention, plasma is not accelerated by an electric field or the like during plasma irradiation. For this reason, it is difficult for plasma to roughen the outer peripheral surface.

  Further, according to the microwave plasma processing apparatus of the present invention, the passage cross-sectional area is reduced when the microwave is caused to flow from the waveguide to the slit. For this reason, the electric field strength of the microwave can be increased in the vicinity of the slit. Therefore, the plasma generating gas can be reliably ionized even under a reduced pressure condition, in other words, under a substantially atmospheric pressure condition. Thus, according to the microwave plasma processing apparatus of the present invention, a vacuum facility is unnecessary. For this reason, the equipment structure is simple.

  In addition, when the production line of the object to be processed is under a substantially atmospheric pressure condition, the microwave plasma processing apparatus of the present invention can be installed in the production line (of course, when not installed in the production line (1) ) Included in the configuration)). If it carries out like this, the process to an outer peripheral surface can be performed as part of the flow operation | work of a manufacturing line.

  Further, according to the microwave plasma processing apparatus of the present invention, the microwave propagates through the waveguide (space) instead of the dielectric substrate. For this reason, a dielectric substrate is unnecessary. Therefore, according to the microwave plasma processing apparatus of the present invention, the equipment structure is simple also in this respect.

  (1-1) Preferably, in the configuration of the above (1), the slit is disposed in a portion corresponding to a multiple (1/2 wavelength, 1/4 wavelength included) of the wavelength of the microwave. Better to do.

  According to this configuration, the slit is arranged at a portion where the resonance phenomenon due to the standing wave occurs. For this reason, the electric field strength of the microwave can be further increased. Further, plasma can be generated even when the input power of the microwave is small.

(2) Preferably, in the configuration of (1) above, the processing object is movable in the axial direction relative to the slit, and the slit extends in the circumferential direction. If you and it is not good.

  Here, “the processing object can move in the axial direction relative to the slit” means that the processing object can move in the axial direction with respect to the stationary slit. Further, it means that the slit is movable in the axial direction with respect to the stationary processing object. Further, it means that the processing object and the slit can move together while changing the relative positional relationship in the axial direction. Further, it includes that the processing object is movable in the axial direction while rotating relative to the slit.

  According to this configuration, the extending direction of the slit and the moving direction of the outer peripheral surface of the processing object are substantially orthogonal. For this reason, a predetermined process can be performed to the wide part of the outer peripheral surface of a process target object in a short time.

(3) Preferably, in the configuration of the above (1) or (2), the inner peripheral wall portion and the outer peripheral wall portion are substantially similar to each other in outer shape in a cross section perpendicular to the axis, and are arranged substantially coaxially. it is not good to be a configuration that is.

  According to this configuration, the waveguides can be arranged substantially evenly on the outer side in the axial direction of the irradiation unit. For this reason, it can suppress that plasma becomes non-uniform | heterogenous resulting from the circumferential direction position of the slit in an inner peripheral wall part.

(4) In the configuration of the above (2) or (3), said slit it is better to adopt a configuration that an annular shape extending in the circumferential direction have good. According to this configuration, the slit has a ring shape (endless ring shape). For this reason, a predetermined process can be given to the outer peripheral surface of a process target object over the perimeter. A plurality of slits may be arranged.

(5) In the configuration of the above (2) or (3), said slit is better to adopt a configuration that exhibits a partial arc shape extending in the circumferential direction have good. According to this configuration, the slit has a partial arc shape. For this reason, a predetermined process can be performed to the predetermined circumferential direction area of the outer peripheral surface of a process target object. A plurality of slits may be arranged.

(6) Preferably, in the configuration of the above (5), a plurality of the slits are arranged, and the axial projection planes of the plurality of slits have a ring shape continuous in the circumferential direction. not good.

  Here, the plurality of slits forming the ring-shaped axial projection surface may be all or a part of the arranged slits. In other words, the axial projection planes may be formed over not only 360 ° but also the circumferential section beyond it by connecting all the axial projection planes of the arranged slits. For example, a plurality of slits are spirally arranged on the inner peripheral wall portion, and the configuration includes a case where the spiral extends one or more times in the circumferential direction.

  According to this configuration, a ring-shaped axial projection surface is formed by connecting the axial projection surfaces of the plurality of slits. For this reason, a predetermined process can be given to the said outer peripheral surface over the perimeter by passing the outer peripheral surface of a process target object through the axial direction inner side of a some slit.

(7) Preferably, in any one of the constitutions (1) to (6), the object to be treated is made of a fluororesin and is laminated on the cylindrical inner layer and on the radially outer side of the inner layer. A pipe member having a cylindrical outer layer made of a resin, and the predetermined treatment is a surface modification that improves the adhesion of the outer peripheral surface of the inner layer to the inner peripheral surface of the outer layer. If you as a constituent is the quality processing is not good.

  That is, in this configuration, the surface modification treatment is performed on the outer peripheral surface of the inner layer of the piping member having a multilayer structure by using the microwave plasma processing apparatus of the present invention. According to this configuration, the interlayer adhesion between the inner layer and the outer layer is improved. For this reason, the piping member which an inner layer and an outer layer cannot peel easily can be produced.

  ADVANTAGE OF THE INVENTION According to this invention, the microwave plasma processing apparatus which is easy to perform a predetermined process to the outer peripheral surface of a cylindrical or columnar process target object can be provided.

  Hereinafter, embodiments of the microwave plasma processing apparatus of the present invention will be described.

<First embodiment>
[Configuration of microwave plasma processing equipment]
First, the configuration of the microwave plasma processing apparatus of this embodiment will be described. The microwave plasma processing apparatus of this embodiment performs surface modification treatment on the outer peripheral surface of the inner layer of the piping member under a substantially atmospheric pressure (= 1.013 × 10 ⁵ Pa or a pressure in the vicinity of the pressure). It is.

  FIG. 1 shows a perspective view of the microwave plasma processing apparatus of the present embodiment. FIG. 2 shows an exploded perspective view of the microwave plasma processing apparatus. FIG. 3 shows a longitudinal sectional view of the microwave plasma processing apparatus. As shown in FIGS. 1 to 3, the microwave plasma processing apparatus 1 of the present embodiment includes a first waveguide 2 and a second waveguide 3.

  The first waveguide 2 includes a rectangular tube part 20, an end plate 21, a holding part 22, and a first waveguide path 23. The rectangular tube portion 20 is made of metal. The rectangular tube portion 20 extends in the front-rear direction. An inner peripheral wall portion holding hole 200 is formed in the lower wall of the rectangular tube portion 20. An outer peripheral wall portion attachment hole 201 is formed in the upper wall of the rectangular tube portion 20. The inner peripheral wall portion holding hole 200 and the outer peripheral wall portion mounting hole 201 face each other in the vertical direction. The end plate 21 is made of stainless steel and has a rectangular shape. The end plate 21 seals the front end opening of the rectangular tube portion 20. A first waveguide 23 is defined inside the rectangular tube portion 20. As shown in FIG. 3, the microwave propagates from the microwave oscillator 90 to the first waveguide path 23 through the incident side power monitor 91 → isolator 92 → reflection side power monitor 93 → matching unit 94. To do. The holding | maintenance part 22 is metal, Comprising: The taper cylinder shape which sharpens toward the upper direction from the downward direction is exhibited. The holding portion 22 is erected from the upper surface (inner surface) of the lower wall of the rectangular tube portion 20. The holding part 22 is arranged at the rim of the inner peripheral wall part holding hole 200.

  The second waveguide 3 includes an inner peripheral wall portion 30, an outer peripheral wall portion 31, an end plate 32, a second waveguide passage 33, an irradiation portion 34, and a gas supply pipe 35. The second waveguide 33 is included in the waveguide of the present invention. The second waveguide 3 is connected to the first waveguide 2 at a substantially right angle.

  The inner peripheral wall portion 30 is made of metal and has a cylindrical shape. The inner peripheral wall portion 30 extends in the vertical direction. The lower end of the inner peripheral wall portion 30 passes through the outer peripheral wall portion mounting hole 201 and the inner peripheral wall portion holding hole 200 of the rectangular tube portion 20. That is, the lower end of the inner peripheral wall portion 30 protrudes downward from the rectangular tube portion 20. The outer peripheral surface near the lower end of the inner peripheral wall portion 30 is fixed by the inner peripheral edge of the inner peripheral wall portion holding hole 200 and the holding portion 22. Thus, the inner peripheral wall portion 30 is fixed to the lower wall of the rectangular tube portion 20.

  FIG. 4 shows an enlarged view in the frame IV of FIG. As shown in FIG. 4, a slit 300 is formed in the inner peripheral wall portion 30. The slit 300 is disposed in a portion corresponding to a multiple of the microwave wavelength (including ½ wavelength and ¼ wavelength). The slit 300 has a ring shape extending in the circumferential direction. In other words, the inner peripheral wall portion 30 is divided into two in the vertical direction by the slit 300. The lower part of the inner peripheral wall part 30 is fixed to the lower wall of the rectangular tube part 20 as described above. The upper part of the inner peripheral wall portion 30 is fixed to the inner peripheral edge of the end plate 32 as will be described later. That is, the slit 300 is defined by fixing the upper part and the lower part of the inner peripheral wall part 30 to the adjacent members. The axial width of the slit 300 is set to about 1 mm.

  The outer peripheral wall 31 is made of metal and has a cylindrical shape. The outer peripheral wall portion 31 has a shorter axis than the inner peripheral wall portion 30. That is, the outer peripheral wall portion 31 has a shorter axial length (upward / downward total length) than the inner peripheral wall portion 30. In addition, the outer peripheral wall portion 31 has a larger diameter than the inner peripheral wall portion 30. The outer peripheral wall portion 31 is disposed on the outer side in the radial direction (axial direction) of the inner peripheral wall portion 30. The outer peripheral wall portion 31 and the inner peripheral wall portion 30 are disposed substantially coaxially. The lower end of the outer peripheral wall portion 31 is attached to the rim of the outer peripheral wall portion attachment hole 201 of the rectangular tube portion 20. That is, the outer peripheral wall portion 31 is fixed to the upper wall of the rectangular tube portion 20. A gas supply pipe attachment hole 310 is formed in the outer peripheral wall portion 31. The gas supply pipe mounting hole 310 faces the slit 300 in the radial direction.

  The second waveguide 33 is defined between the inner peripheral surface of the outer peripheral wall portion 31 and the outer peripheral surface of the inner peripheral wall portion 30. That is, the space that forms the second waveguide 33 has a cylindrical shape. The second waveguide 33 is connected to the first waveguide 23 at a substantially right angle via the outer peripheral wall mounting hole 201.

  The end plate 32 is made of stainless steel and has a ring plate shape. The end plate 32 seals the upper end of the outer peripheral wall portion 31. The second waveguide 33 is blocked from the outside by the end plate 32. The inner peripheral edge of the end plate 32 is fixed to the outer peripheral surface of the inner peripheral wall portion 30.

  The irradiation unit 34 is disposed on the radially inner side of the inner peripheral wall 30. As shown in FIG. 4, the irradiation unit 34 is arranged on the entire inner side in the radial direction of the slit 300. Plasma P is generated in the irradiating section 34 as indicated by dotted line hatching in FIG.

  The gas supply pipe 35 is made of stainless steel. The gas supply pipe 35 is attached to the edge of the gas supply pipe attachment hole 310 of the outer peripheral wall portion 31. Argon gas flows inside the gas supply pipe 35. Argon gas is contained in the plasma generating gas of the present invention.

  The inner layer 80 of the piping member is made of an ethylene-tetrafluoroethylene copolymer (ETFE) and has a cylindrical shape. ETFE is included in the fluororesin of the present invention. The inner layer 80 has a longer axis than the inner peripheral wall portion 30. That is, the inner layer 80 is longer in the axial direction overall length (vertical overall length) than the inner peripheral wall portion 30. Further, the inner layer 80 has a smaller diameter than the inner peripheral wall portion 30. The inner layer 80 and the inner peripheral wall portion 30 are disposed substantially coaxially. The inner layer 80 passes through the radially inner side of the inner peripheral wall portion 30 from the lower side to the upper side.

[Movement of microwave plasma processing equipment]
Next, the movement of the microwave plasma processing apparatus 1 according to this embodiment when the surface modification process is performed on the inner layer 80 of the piping member will be described. First, as shown in FIG. 3, the microwave power supply 95 is turned on. When the microwave power source 95 is turned on, the microwave oscillator 90 generates a microwave. The generated microwave is introduced into the first waveguide 23 through the incident side power monitor 91 → isolator 92 → reflection side power monitor 93 → matching unit 94.

  At this time, the output of the generated microwave is monitored by the power monitor 91 on the incident side. Further, the output of the reflected microwave is monitored by the power monitor 93 on the reflection side. Further, the output of the reflected microwave is attenuated by the isolator 92. Further, the matching unit 94 adjusts the amount of reflected microwaves.

  Next, the microwave is introduced from the first waveguide 23 into the second waveguide 33. The introduced microwave propagates through the second waveguide 33 from below to above. Subsequently, the microwave enters the slit 300 of the inner peripheral wall portion 30. Here, the passage sectional area of the slit 300 is extremely small as compared with the passage sectional area of the second waveguide 33. For this reason, when entering the slit 300 from the second waveguide 33, the electric field strength of the microwave becomes extremely high.

  On the other hand, argon gas is supplied from the gas supply pipe 35 to the second waveguide 33 through the gas supply pipe attachment hole 310. Argon gas enters the slit 300 together with the microwave. When passing through the slit 300, the argon gas is ionized by a high microwave electric field formed in the vicinity of the slit 300. Then, plasma P is generated inside the slit 300 in the radial direction.

  Then, the inner layer 80 of the piping member prepared in advance by melt extrusion molding is inserted from the lower end opening of the inner peripheral wall portion 30. The inner layer 80 passes from the lower side to the upper side in the radial direction inside of the slit 300. At this time, the plasma P is irradiated to the outer peripheral surface 800 of the inner layer 80 all around. The exhaust gas is discharged to the outside from the upper and lower end openings of the inner peripheral wall portion 30. As described above, the inner layer 80 passes through the inner side in the radial direction of the inner peripheral wall portion 30 (specifically, the slit 300), so that the outer peripheral surface 800 is subjected to surface modification treatment. Thereafter, an outer layer made of polyamide 12 (PA12) is laminated on the outer peripheral surface of the inner layer 80 by melt extrusion molding. PA12 is included in the polyamide resin of the present invention.

  In FIG. 5, the perspective view of the piping member produced using the microwave plasma processing apparatus of this embodiment is shown. FIG. 6 shows a radial cross-sectional view of the piping member. As shown in FIGS. 5 and 6, the piping member 8 includes an inner layer 80 and an outer layer 81. A functional group such as a hydroxyl group or a carboxyl group is imparted to the outer peripheral surface 800 of the inner layer 80 (specifically, a portion having a predetermined depth from the outer peripheral surface 800) by surface modification as shown by thin line hatching in FIG. . The functional group is melt-bonded to the PA 12 of the outer layer 81 by heat. For this reason, the inner layer 80 and the outer layer 81 are bonded with a high interlayer adhesive force.

[Function and effect]
Next, the effect of the microwave plasma processing apparatus 1 of this embodiment is demonstrated. According to the microwave plasma processing apparatus 1 of the present embodiment, the second waveguide 33 → the slit 300 → the irradiation unit 34 is arranged from the radially outer side to the radially inner side. Further, the outer peripheral surface 800 of the inner layer 80 passes through the irradiation unit 34. For this reason, the plasma P is applied to the outer circumferential surface 800 from multiple directions so as to concentrate from the radially outer side toward the radially inner side, in other words, at the axis of the inner layer 80. Therefore, according to the microwave plasma processing apparatus 1 of the present embodiment, it is easy to subject the outer peripheral surface 800 to surface modification treatment. Further, according to the microwave plasma processing apparatus 1 of the present embodiment, the plasma P is not accelerated by an electric field or the like when the plasma P is irradiated. For this reason, it is difficult for the plasma P to roughen the outer peripheral surface 800.

  Further, according to the microwave plasma processing apparatus 1 of the present embodiment, when the microwave flows from the second waveguide 33 into the slit 300, the passage cross-sectional area becomes small. For this reason, the electric field strength of the microwave can be increased in the vicinity of the slit 300. Therefore, the argon gas can be reliably ionized even under reduced pressure conditions, in other words, under substantially atmospheric pressure conditions. Thus, according to the microwave plasma processing apparatus 1 of this embodiment, a vacuum facility is unnecessary. For this reason, the equipment structure is simple.

  Further, according to the microwave plasma processing apparatus 1 of the present embodiment, the microwave propagates through the first waveguide 23 (space) and the second waveguide 33 (space) instead of the dielectric substrate. For this reason, a dielectric substrate is unnecessary. Therefore, according to the microwave plasma processing apparatus 1 of the present embodiment, the equipment structure is simple also in this respect.

  Further, according to the microwave plasma processing apparatus 1 of the present embodiment, the extending direction (circumferential direction) of the slit 300 and the moving direction (axial direction) of the outer peripheral surface 800 are substantially orthogonal. The slit 300 has a ring shape. For this reason, the surface modification treatment can be performed on substantially the entire outer peripheral surface 800 of the inner layer 80 only by passing the radial inner side of the inner peripheral wall portion 30 in the axial direction. That is, the surface modification treatment can be performed on substantially the entire outer peripheral surface 800 in a short time.

  Further, according to the microwave plasma processing apparatus 1 of the present embodiment, the outer peripheral wall portion 31 and the outer peripheral wall portion 31 have substantially similar (circular) outer shapes in radial cross section. In addition, the inner peripheral wall portion 30 and the outer peripheral wall portion 31 are disposed substantially coaxially. For this reason, the radial width of the second waveguide 33 is substantially constant over the entire circumference. Therefore, it is possible to suppress the plasma P from becoming non-uniform over the entire length in the circumferential direction.

  Moreover, when the surface modification process of the outer peripheral surface 800 is performed using the microwave plasma processing apparatus 1 of the present embodiment, the interlayer adhesive force between the inner layer 80 and the outer layer 81 is improved. For this reason, the piping member 8 which the inner layer 80 and the outer layer 81 cannot peel easily can be produced.

<Second embodiment>
The difference between the microwave plasma processing apparatus of the present embodiment and the microwave plasma processing apparatus of the first embodiment is only the shape, the number of arrangement, and the arrangement location of the slits on the inner peripheral wall portion. Therefore, only the differences will be described here.

  FIG. 7 is a perspective view of the inner peripheral wall portion of the microwave plasma processing apparatus of this embodiment. FIG. 8 is a development view of the inner peripheral wall portion (a view opened from the one-dot chain line in FIG. 7). In addition, about the site | part corresponding to FIG. 2, it shows with the same code | symbol.

  As shown in FIGS. 7 and 8, a total of 20 slits 301 are arranged on the inner peripheral wall portion 30. The slit 301 has a partial arc shape extending in the circumferential direction. An irradiation unit is arranged on the inner side in the radial direction of the slit 301. Plasma is generated in the irradiation unit.

  The 20 slits 301 are arranged in a spiral shape. The 20 slits 301 make two rounds in the circumferential direction on the inner peripheral wall portion 30. The centers of slits 301 adjacent to each other in the circumferential direction are spaced apart by 36 °. The axial projection surfaces of the ten slits 301 that are continuous in the circumferential direction have a ring shape.

  When the outer peripheral surface of the inner layer passes through the inner side in the radial direction of the inner peripheral wall portion 30, an arbitrary part (for example, a 180 ° part shown in FIG. 8) passes through the inner side in the radial direction of the two slits 301. Become. For this reason, the surface modification treatment is performed twice on any part of the outer peripheral surface.

  The microwave plasma processing apparatus of the present embodiment has the same operational effects as the microwave plasma processing apparatus of the first embodiment with respect to the parts having the same configuration. In addition, according to the microwave plasma processing apparatus of the present embodiment, the axial projection surfaces of the ten slits 301 are connected to form a ring-shaped axial projection surface. For this reason, the surface modification treatment can be performed on the outer peripheral surface of the inner layer over the entire periphery. Further, all the twenty slits 301 make two rounds in the circumferential direction of the inner peripheral wall portion 30. For this reason, the surface modification treatment can be performed twice on the outer peripheral surface of the inner layer. Further, according to the plasma processing apparatus of the present embodiment, the inner peripheral wall portion 30 is not divided into two in the vertical direction. For this reason, attachment of the inner peripheral wall part 30 with respect to an adjacent member is easy. Moreover, there is little possibility that the axial width of the slit 301 will change depending on the state of attachment of the inner peripheral wall portion 30 to the adjacent member.

<Others>
The embodiment of the microwave plasma processing apparatus of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, in the first embodiment, only one slit 300 is disposed on the inner peripheral wall portion 30, but the number of slits 300 is not particularly limited. A plurality of slits 300 may be arranged apart from each other in the axial direction. In this way, the surface modification treatment can be performed a plurality of times on the outer peripheral surface 800 of the inner layer 80.

  In the second embodiment, a total of 20 slits 301 are spirally arranged on the inner peripheral wall portion 30, but may be arranged in a dotted circle, for example. The number of turns of the spiral formed by the slit 301 with respect to the inner peripheral wall portion 30 is not particularly limited. In the second embodiment, as shown in FIG. 8, the shape of the slit 301 is rectangular, but is elliptical or oval (a shape in which a pair of opposing semicircles are connected by a pair of straight lines). It is good. Moreover, you may use suitably combining the ring-shaped slit 300 of 1st embodiment, and the partial arc-shaped slit 301 of 2nd embodiment.

  In the above embodiment, the inner layer 80 is moved from the lower side to the upper side without rotating in the circumferential direction. However, the inner layer 80 may be moved from the lower side to the upper side while rotating in the circumferential direction. In the above-described embodiment, the first waveguide 2 is disposed on the upstream side of the second waveguide 3. However, if the desired microwave can be propagated to the second waveguide 33, the first waveguide 2 is disposed. The wave tube 2 may not be arranged.

  Moreover, in the said embodiment, although the axial direction width | variety of the slits 300 and 301 was set to about 1 mm, the axial direction width | variety is not specifically limited. Preferably, 0.02 mm or more and 1 mm or less are better. The reason for this is that when the thickness is less than 0.02 mm, arc discharge may occur in the slits 300 and 301 and the slits 300 and 301 may be damaged. In addition, if it exceeds 1 mm, high-power microwave incident power is required to generate plasma.

  In addition, the inner peripheral wall portion 30 and the outer peripheral wall portion 31 may have a rectangular tube shape such as a triangular tube shape, a square tube shape, or a pentagonal tube shape in addition to a cylindrical shape. Moreover, the inner peripheral wall part 30 and the outer peripheral wall part 31 do not need to be arrange | positioned substantially coaxially.

  In the above embodiment, argon gas is used as the plasma generating gas. However, the type of gas is not particularly limited. For example, one kind of a rare gas composed of argon (Ar), helium (He), neon (Ne), krypton (Kr) and xenon (Xe), or a molecular gas composed of hydrogen, nitrogen, oxygen, etc. Two or more kinds of gases may be selected as appropriate, and the selected gases may be used as plasma generation gases. Further, in order to stabilize the generated plasma, an organic solvent such as acetone may be vaporized and mixed in addition to the plasma generating gas.

  Moreover, in the said embodiment, ETFE was used as a fluorine resin of this invention. However, for example, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), vinylidene fluoride resin (PVDF), tetrafluoroethylene resin (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP). ), Ethylene-chlorotrifluoroethylene copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene Fluoride-tetrafluoroethylene-hexafluoropropylene-perfluoroalkoxy vinyl ether copolymer, tetrafluoroethylene-vinylidene fluoride-he Sa hexafluoropropylene - or the like may be used perfluoroalkoxy vinyl ether copolymer. Two or more of these fluororesins may be used in combination.

  Moreover, in the said embodiment, PA12 was used as a polyamide-type resin of this invention. However, for example, polyamide 6 (PA6), polyamide 66 (PA66), polyamide 99 (PA99), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 11 (PA11), polyamide 912 (PA912), polyamide 6 and polyamide A copolymer of 66 (PA6 / 66), a copolymer of polyamide 6 and polyamide 12 (PA6 / 12), or the like may be used. Two or more of these polyamide resins may be used in combination. The materials of the first waveguide 2 and the second waveguide 3 are not particularly limited. In addition to stainless steel, aluminum or copper may be used.

  In addition, the rectangular tube portion 20 is preferably made of stainless steel in order to maintain strength. In order to reduce the reflection of microwaves, the inner surface of the rectangular tube portion 20 may be plated with copper, silver, or the like having high conductivity. Similarly, in order to reduce the reflection of the microwave, the surface of the end plate 21 to which the microwave hits may be plated with copper or silver having high conductivity. Further, the inner peripheral wall portion 30 is preferably made of copper or aluminum having high conductivity. Further, the outer peripheral wall portion 31 is preferably made of stainless steel in order to maintain strength. In order to reduce the reflection of microwaves, the inner surface of the outer peripheral wall portion 31 may be plated with copper, silver or the like having high conductivity. Similarly, in order to reduce the reflection of the microwave, the surface of the end plate 32 on which the microwave hits may be plated with copper, silver or the like having a high conductivity.

  Also, the irradiation time of plasma P on the outer peripheral surface 800 of the inner layer 80 is not particularly limited. For example, the irradiation time may be 1 second or more and 200 seconds or less. Further, the frequency of the microwave is not particularly limited. For example, a microwave having a frequency of 433 MHz to 2.45 GHz can be used. It is preferable to use a microwave with a frequency of 2.45 GHz. The reason is that the frequency conforms to the Radio Law.

It is a perspective view of the microwave plasma processing apparatus of a first embodiment. It is a disassembled perspective view of the same microwave plasma processing apparatus. It is sectional drawing of the front-back direction of the same microwave plasma processing apparatus. FIG. 4 is an enlarged view in a frame IV of FIG. 3. It is a perspective view of the piping member produced using the same microwave plasma processing apparatus. It is radial direction sectional drawing of the piping member. It is a perspective view of the internal peripheral wall part of the microwave plasma processing apparatus of 2nd embodiment. It is an expanded view of the inner peripheral wall part.

Explanation of symbols

1: microwave plasma processing apparatus, 2: first waveguide, 3: second waveguide, 8: piping member.
20: Square tube portion, 21: End plate, 22: Holding portion, 23: First waveguide passage, 30: Inner peripheral wall portion, 31: Outer peripheral wall portion, 32: End plate, 33: Second waveguide passage (Wave path), 34: irradiation unit, 35: gas supply pipe, 80: inner layer, 81: outer layer, 90: microwave oscillator, 91: power monitor, 92: isolator, 93: power monitor, 94: matching device, 95: Microwave power supply.
200: inner peripheral wall holding hole, 201: outer peripheral wall mounting hole, 300: slit, 301: slit, 310: gas supply pipe mounting hole, 800: outer peripheral surface.
P: Plasma.

Claims (9)

A cylindrical inner peripheral wall having a slit;
A cylindrical outer peripheral wall disposed on the outer side in the axial direction of the inner peripheral wall;
A waveguide that is partitioned between the inner peripheral wall portion and the outer peripheral wall portion and through which the microwave propagates;
An irradiation section that is partitioned inward in the axial direction of the inner peripheral wall portion, communicates with the waveguide path through the slit, and in which an outer peripheral surface of a cylindrical or columnar processing object is disposed;
A gas supply pipe for supplying a plasma generating gas directly or indirectly to the slit;
With
Under substantially atmospheric pressure conditions, the microwave and the plasma generating gas are passed through the slit to concentrate the microwave electric field to form a high electric field near the slit, and the high electric field generates the plasma. Ionizing the working gas to generate a plasma in the irradiated portion, and applying a predetermined treatment to the outer peripheral surface of the object to be treated by the plasma,
The processing object is movable in the axial direction relatively to the slit extending in the circumferential direction,
The microwave plasma processing apparatus, wherein the microwave is introduced into the waveguide from one axial end of the waveguide, propagates in the waveguide in the axial direction, and enters the slit.   2. The microwave plasma processing apparatus according to claim 1, wherein the inner peripheral wall portion and the outer peripheral wall portion are substantially similar to each other in outer shape in a cross section perpendicular to the axial direction, and are disposed substantially coaxially.   The microwave plasma processing apparatus according to claim 1, wherein the slit has a ring shape extending in a circumferential direction.   The microwave plasma processing apparatus according to claim 1, wherein the slit has a partial arc shape extending in a circumferential direction. A plurality of the slits are arranged,
The microwave plasma processing apparatus according to claim 4, wherein the axial projection surfaces of the plurality of slits have a ring shape continuous in the circumferential direction. The object to be treated is an inner layer of a piping member made of a fluororesin and having a cylindrical inner layer and a cylindrical outer layer laminated on a radially outer side of the inner layer and made of a polyamide resin. Yes,
The microwave plasma processing apparatus according to any one of claims 1 to 5, wherein the predetermined treatment is a surface modification treatment that improves adhesion of the outer peripheral surface of the inner layer to the inner peripheral surface of the outer layer.   The microwave plasma processing apparatus according to claim 1, wherein both the inner peripheral wall portion and the outer peripheral wall portion are made of metal.   The outer peripheral wall portion has a gas supply pipe mounting hole arranged on the outer side in the axial direction of the slit,
  The gas supply pipe is attached to the gas supply pipe attachment hole,
  8. The gas supply pipe according to claim 1, wherein the plasma generation gas is supplied to the slit from the outside in the direction perpendicular to the axis through the gas supply pipe mounting hole and the waveguide path. Microwave plasma processing equipment.   The slit is disposed in a portion corresponding to a multiple of the wavelength of the microwave (including a half wavelength and a quarter wavelength),
  The microwave plasma processing apparatus according to any one of claims 1 to 8, wherein an axial width of the slit is 0.02 mm or more and 1 mm or less.

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