JP2008261060A - Barrier film forming internal electrode and film forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrier film forming internal electrode capable of constantly and stably forming a barrier film on a container by preventing falling of an insulating member of the internal electrode in a film forming apparatus. <P>SOLUTION: The barrier film forming internal electrode inserted into the internal part of the plastic container having a mouth part and for forming the barrier film on the inner surface of the plastic container by supplying a medium gas in the plastic container and supplying high frequency power to an external electrode provided outside of the plastic container to generate on the inner surface of the plastic container is provided with a gas supply pipe 101 having a gas flow passage 101a for supplying the medium gas G and the insulation member 103 having a blowing port 102 communicating with the gas flow passage 101a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal electrode for forming a barrier film and a film forming apparatus for forming a barrier film that imparts gas barrier properties in a container such as a resin.

  In recent years, for example, a PET (PET) bottle, which is one of plastic containers, has a DLC (Diamond Like) on its inner surface in order to prevent the permeation of oxygen from the outside and the permeation of carbon dioxide from the inside (for example, carbonated drinking water). An attempt has been made to coat a hard carbon film such as Carbon, and various film forming apparatuses have been proposed (Patent Documents 1, 2, and 3).

  Here, as an apparatus for forming a carbon film on a plastic container using high-frequency plasma CVD, an apparatus according to Patent Document 3 which is a basic invention for coating the inside of the container will be described with reference to FIG. .

As shown in FIG. 9, the film forming apparatus is a film forming apparatus for forming a film by discharge plasma on the inner surface of a plastic container 12 having a mouth portion 11, and has an outer upper portion having a size surrounding the outer periphery of the plastic container 12. An external electrode 13 including an electrode 13-1 and an external lower electrode 13-2; an exhaust pipe 14 attached to an end surface of the external electrode 13 on the side where the mouth portion 11 is located through an insulating member 26; A gas blowing hole for inserting the medium gas G into the plastic container 12 in the electrode 13 from the exhaust pipe 14 side over the substantially entire length of the plastic container 12 and connected to the ground side. An internal electrode 17 in which 16 is formed, an exhaust device (not shown) attached to the exhaust pipe 14, and a gas (not shown) for supplying the medium gas G to the internal electrode 17. A supply device is made by and a high frequency power source 18 connected to said external electrodes 13.
Here, the external electrode 13 is provided in a cylindrical chamber 22 having flanges 21 a and 21 b at the upper and lower ends, and the cylindrical chamber 22 is placed on an annular base 23. . The disc-shaped insulating plate 24 is disposed between the annular base 23 and the bottom side of the external lower electrode 13-2. A cylindrical insulating member 20 is provided at the tip of the gas blowing hole 16 of the internal electrode 17 to prevent local plasma concentration.

  A method for coating a carbon film on a bottle using the apparatus having such a configuration will be described.

First, the plastic container 12 is inserted into the external electrode 13, and the internal gas is exhausted through the gas exhaust pipe 14. After reaching a prescribed degree of vacuum (representative value: 10 ⁻¹ to 10 ⁻⁵ Torr), the medium gas G is supplied to the internal electrode 17 at a flow rate of, for example, 10 to 200 mL / min. 16 is blown out into the plastic container 12. As the medium gas G, for example, aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane, aromatic hydrocarbons, oxygen-containing hydrocarbons, and nitrogen-containing hydrocarbons are used. The pressure in the plastic container 12 is set to 2 × 10 ⁻¹ to 1 × 10 ⁻² Torr, for example, depending on the balance between the gas supply amount and the exhaust amount. Thereafter, high frequency power of 50 to 2000 W is applied from the high frequency power source 18 to the external electrode 13 through the matching unit 36 and the RF input terminal 35.

  By applying such high frequency power to the external electrode 13, plasma is generated between the external electrode 13 and the internal electrode 17. At this time, since the plastic container 12 is accommodated in the external electrode 13 with almost no gap, plasma is generated in the plastic container 12. The medium gas G is dissociated or further ionized by the plasma to generate a film-forming species for forming a carbon film, and this film-forming species is deposited on the inner surface of the container 12 to form a carbon film. After the carbon film is formed to a predetermined thickness, the application of the high-frequency power is stopped, the supply of the medium gas is stopped, the residual gas is exhausted, nitrogen, a rare gas, air, or the like is supplied into the external electrode 13. Return inside to atmospheric pressure. Thereafter, the plastic container 12 is removed from the external electrode 13. In this method, it takes 2-3 seconds to form a carbon film having a thickness of 20 to 30 nm.

JP-A-8-53116 Japanese Patent No. 2788412 (Japanese Patent Laid-Open No. 8-53117) JP 2003-286571 A

  However, in the film forming apparatus, since the insulating material provided in the gas outlet 16 of the internal electrode is cylindrical, it is caused by the difference in coefficient of thermal expansion during film formation over a long period of time. It may be damaged or fall due to thermal stress.

  In such a case, the insulation function will burn out and plasma concentration will occur. For example, in the case of continuous production of plastic containers, etc., it is necessary to pause the production system, resulting in reduced production efficiency. Cause.

  In view of the above problems, the present invention provides an internal electrode for barrier film formation and a film forming apparatus that can prevent the insulating member of the internal electrode in the film forming apparatus from dropping and can always stably form the barrier film of the container. The issue is to provide.

  The first invention of the present invention for solving the above-mentioned problems is an external electrode that is inserted into a plastic container having a mouth, supplies a medium gas into the plastic container, and is provided outside the plastic container. An internal electrode for forming a barrier film on the inner surface of the plastic container by generating discharge plasma on the inner surface of the plastic container by supplying high frequency power to the gas container, and having a gas flow path for supplying a medium gas, A gas supply pipe provided with a recess having a space having a long tip in the axial direction; an insulating member threadedly engaged with an inner surface of the recess of the gas supply pipe and communicating with the gas flow path; And a solid cap member formed with a hole extending in the axial direction to be fitted to the outer periphery of the gas outlet of the insulating member. Have In internal electrode barrier film, wherein the door.

According to a second invention, there is provided an internal electrode for forming a barrier film according to the first invention, wherein the gas supply pipe is integrally provided with a plasma generating part having at least one protrusion or depression. .

A third invention is the internal electrode for forming a barrier film according to the second invention, wherein the plasma generating part is made of a material having high thermal conductivity.

According to a fourth invention, there is provided an internal electrode for forming a barrier film according to the first invention, wherein a seal member for sealing the screwed portion is provided.

A fifth invention is an internal electrode for forming a barrier film according to any one of the first to fourth inventions, wherein the gas supply pipe is made of metal.

According to a sixth aspect of the present invention, there is provided a film forming apparatus including the barrier film forming internal electrode according to any one of the first to fifth aspects, wherein the barrier film is formed on the inner surface of the plastic container.

A seventh invention is a film forming apparatus for applying a barrier film to the inner surface of a plastic container having a mouth by discharge plasma, the outer electrode having a size surrounding the outer periphery of the plastic container, and the side on which the mouth is located An exhaust pipe attached to the end face of the external electrode through an insulating member, and inserted into the plastic container in the external electrode over the entire length of the plastic container from the exhaust pipe side to the ground. Any one of the first to fifth barrier film-forming internal electrodes connected to the side, an exhaust device attached to the exhaust pipe, a gas supply device for supplying a medium gas to the internal electrode, and the external electrode And a high-frequency power source connected to the film forming apparatus.

  According to the present invention, when a barrier film is formed on the inner surface of a plastic container or the like, the film can be stably formed over a long period of time. Thereby, the gas barrier film on the inner surface of the plastic container can be formed while maintaining the film forming quality for a long period of time.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  FIG. 2 shows an outline of the barrier film forming internal electrode according to the first embodiment of the present invention. As shown in FIG. 2, the barrier film forming internal electrode 100-1 according to the present embodiment is inserted into a plastic container having a mouth portion, and a medium gas is supplied into the plastic container. Supplying a medium gas G, which is an internal electrode for forming a barrier film on the inner surface of the plastic container by generating a discharge plasma on the inner surface of the plastic container by supplying high-frequency power to an external electrode provided outside A gas supply pipe 101 having a gas flow path 101a; and an insulating member 103 having a gas outlet 102 which is screwed flush with an end of the gas supply pipe 101 and communicates with the gas flow path 101a. To do.

Since the gas outlet 102 is made of an insulating material, local concentration of plasma can be prevented.
Here, examples of the material of the insulating member 103 include materials having heat resistance such as fluororesin, PEEK, and polyimide, and materials having high thermal conductivity and heat shock resistance such as alumina, zirconia, titania, and silica. it can.

Moreover, since there is no protrusion in the entire internal electrode shape, local plasma concentration can be prevented.
The gas supply pipe 101 is made of metal, a female part 101b is formed in the metal gas supply pipe 101, a male part 104 is formed in the insulating member 103, and both are screwed together. It becomes a structure which improves sealing performance. In addition, the sealing performance can be further improved by providing the sealing portion 120 at the screwing portion.
Here, examples of the material of the seal portion 120 include a tape made of Teflon (registered trademark).

  Further, when the thermal expansion is repeated by making the screwed male part 104 into a tapered shape by forming the female part 101b constituting the screwed part into a divergent shape that gradually spreads toward the back. In this case, the screwability may be maintained.

As a result, a stable barrier film can be formed on the inner surface of the plastic container even after long-term operation.
Therefore, the durability of the internal electrode component is improved, and its maintainability is improved.

  Here, examples of the container include a plastic container for foods and pharmaceuticals, and other than the container, it is effective as a gas barrier film for a film or the like. Further, it can be applied to a container filled with fuel such as a gasoline tank.

Here, examples of the plastic include known materials such as polyester films such as polyethylene terephthalate, polyolefin films such as polyethylene, polypropylene, and polybutene, polystyrene films, polyamide films, polycarbonate films, and polyacrylonitrile films .

  Here, in the present invention, the gas barrier film refers to a film formed on the surface of a substrate and having gas impermeability. Examples of the gas barrier film include a carbon film such as an amorphous carbon film and a film such as a silicon film.

Here, the amorphous carbon film is a carbon film having an amorphous structure in an intermediate form of diamond (bond of carbon atoms is SP ³ bond) and graphite (bond of carbon atoms is SP ² bond), This includes a hard carbon film and a soft carbon film. The hard carbon film also includes an amorphous DLC (Diamond Like Carbon) film mainly composed of SP ³ bonds.

As a method for producing such an amorphous carbon film, a known chemical vapor deposition method (CHEMICAL Vapor Deposition, CVD) represented by a CVD method, a thermal CDV method, a plasma CVD method, or the like can be used.
For example, a known physical vapor deposition (PVD) method represented by a reactive sputtering method, an ion plating method, an arc vapor deposition method, an ion vapor deposition method, a plasma ion implantation method, or the like may be used. it can.
In addition, in this invention, when applying CVD method rather than the said PVD method, the effect of this invention is exhibited more. This is because the film produced by the CVD method contains more dangling bonds in the amorphous carbon film.

Here, the medium gas is basically hydrocarbon, for example, alkanes such as methane, ethane, propane, butane, pentane and hexane; alkenes such as ethylene, propylene, butene, pentene and butadiene; alkynes such as acetylene Aromatic hydrocarbons such as benzene, toluene, xylene, indene, naphthalene and phenanthrene; cycloparaffins such as cyclopropane and cyclohexane; cycloolefins such as cyclopentene and cyclohexene can be used, and other carbon monoxide can also be used. . Thereby, for example, an amorphous carbon film for preventing permeation of carbon dioxide from, for example, carbonated drinking water filled in the container can be coated. Further, the amorphous carbon film may be a film having a gradient function.
In the case of using the PVD method, a solid evaporation source can also be used.

Hereinafter, an example of a film forming apparatus for forming an amorphous carbon film provided with an internal electrode according to the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing a film forming apparatus according to this embodiment. As shown in FIG. 1, the film forming apparatus according to the present embodiment is a film forming apparatus that forms a film by discharge plasma on the inner surface of a plastic container 12 having a mouth portion 11, and is large enough to surround the outer periphery of the plastic container 12. An external electrode 13 having a thickness, an exhaust pipe 14 attached to an end surface of the external electrode 13 on the side where the mouth portion 11 is located via an insulating member, and the plastic container 12 in the external electrode 13 in the plastic container 12. The insulating member 103 is inserted from the exhaust pipe 14 over almost the entire length of the plastic container 12 and connected to the ground side, and has a gas outlet 102 for blowing out the medium gas G. The internal electrode 100-1 shown in FIG. 2, the exhaust device (not shown) attached to the exhaust pipe 14, and the medium gas G for supplying the medium gas G to the internal electrode 17 are not shown. Scan feed device and is made to and a high frequency power source 18 connected to said external electrodes 13.

  Here, the external electrode 13 is provided in a cylindrical chamber 22 composed of a chamber (upper) 22-1 and a chamber (lower) 22-2 having flanges 21a and 21b at upper and lower ends, The cylindrical chamber 22 is placed on an annular base 23. The cylindrical chamber 22 and the external electrode 13 can be divided into an upper side and a lower side, and are detachably attached. The disc-shaped insulating plate 24 is disposed between the base 23 and the bottom side of the external lower electrode 13-2.

  Note that a conductive connector 41 and a vacuum seal (O-ring) 42 are interposed between the divided portion of the cylindrical chamber 22 and the external electrode 13 at the divided portion. And in order to store the plastic container 12 in the external electrode 13, the division part is moved up and down integrally.

  Further, in this embodiment, a cylindrical spacer 25 made of a dielectric material having a hollow portion formed by combining a column and a truncated cone corresponding to the mouth and shoulder of the plastic container 12 to be inserted therein is provided on the outside. It is disposed inside the upper electrode 13-1. The columnar spacer 25 is fixed by a screw (not shown) screwed from an annular insulating member 26 placed thereon. When the plastic container 12 is inserted from the bottom side of the external electrode 13 by inserting and fixing the columnar spacer 25 to the top of the external electrode 13 in this way, the mouth and shoulder of the plastic container 12 become the circular shape. The plastic container 12 is located in the cavity of the columnar spacer 25 and the other outer periphery of the plastic container 12 is located on the inner surface of the external electrode 13.

  Examples of the dielectric material constituting the columnar spacer 25 include plastic or ceramic. Various plastics can be used, and a fluorine-based resin such as polytetrafluoroethylene having a low high-frequency loss and excellent heat resistance is particularly preferable. As the ceramic, alumina, steatite with low high-frequency loss, or Macor with high machinability is preferable.

  The gas exhaust pipe 14 having upper and lower flanges 31 a and 31 b is placed on the upper flange 21 a of the chamber 22 and the upper surface of the annular insulating member 26. The lid 32 is attached to the upper flange 31 a of the exhaust pipe 14.

  A high frequency power source 18 that outputs high frequency power is connected to the external electrode 13 through a cable 34 and a power supply terminal 35. The matching unit 36 is interposed in the cable 34 between the high-frequency power source 18 and the power supply terminal 35.

  The internal electrode 100-1 is arranged over the entire length in the longitudinal direction of the plastic container 12 inserted in the external electrode 13 and the disc-like spacer 25, and the upper end of the internal electrode 100-1 is the plastic container 12. It also serves as the gas supply pipe located on the mouth 11 side. The gas supply pipe also serves as a ground terminal.

  The gas blowing hole may be opened on the lower side wall of the internal electrode 100-1 so as to communicate with the gas flow path 37. In this case, it is preferable that the gas blowing hole opens in a side region within a range from the bottom of the internal electrode 100-1 to 25% of the length inserted into the plastic container 12. The diameter of the internal electrode 100-1 is set to be equal to or smaller than the diameter of the cap of the plastic container, and the length thereof is a length that can be inserted over almost the entire length of the plastic container 12.

  The internal electrode 100-1 is made of a metal material having heat resistance such as tungsten or stainless steel, but may be made of aluminum. Further, if the surface of the internal electrode 100-1 is smooth, the carbon film deposited on the surface of the internal electrode 100-1 may be easily peeled off. For this reason, it is preferable that the surface of the internal electrode is previously sandblasted to increase the surface roughness and make it difficult to peel off the carbon film deposited on the surface.

  Next, a method for manufacturing a plastic container having an inner surface coated with an amorphous carbon film using the film forming apparatus described above will be described. The upper electrode and the chamber are divided by a pusher (not shown), and the inside is opened. Subsequently, after the plastic container 12 is inserted into the opened external electrode 13, the external electrode and the chamber are returned to the original state by a pusher (not shown). At this time, the plastic container 12 communicates with the exhaust pipe 14 through its mouth.

  Next, the exhaust pipe 14 and the gas inside and outside the plastic container 12 are exhausted through the exhaust pipe 14 by an exhaust means (not shown). The medium gas G is supplied to the gas flow path 101a of the internal electrode 100-1, and is blown into the plastic container 12 from the gas blowing hole 102 of the internal electrode 100-1. The medium gas G further flows toward the mouth portion 11 of the plastic container 12. Subsequently, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic container 12 is set to a predetermined gas pressure.

  Next, high frequency power is supplied from the high frequency power source 18 to the external electrode 13 through the cable 34, the matching unit 36 and the power supply terminal 35. At this time, discharge plasma is generated between the external electrode 13 (substantially the inner surface of the plastic container) and the grounded internal electrode 100-1. The medium gas G is dissociated by the discharge plasma, and the generated film formation species is deposited on the inner surface of the plastic container 12 to form an amorphous carbon film.

  After the film thickness of the amorphous carbon film reaches a predetermined thickness, the supply of the high frequency power from the high frequency power supply 18 is stopped, the supply of the medium gas G is stopped, the residual gas is exhausted, and the gas is exhausted. Stop. After this stop, nitrogen, rare gas, air or the like is supplied into the plastic container 12 through the gas outlet 102 or the exhaust pipe 104 of the gas flow path 101a of the internal electrode 100-1, and the inside and outside of the plastic container 12 are brought to atmospheric pressure. Return and remove the inner carbon film coated plastic container. Thereafter, the plastic container is exchanged according to the above-described order, and the next plastic container coating operation is started.

  Since the internal electrode 100-1 according to the present embodiment is formed by screwing the insulating member 103 into the gas supply pipe 101, it can be formed without dropping over a long period of time.

Next, another embodiment according to the present invention will be described. Since the film forming apparatus is the same as that shown in FIG. 1, the description of the film forming apparatus is omitted in the description of the following embodiments.
FIG. 3 shows an outline of the internal electrode for forming a barrier film according to the second embodiment of the present invention. As shown in FIG. 3, an inner electrode 100-2 for forming a barrier film according to the present embodiment is inserted into a plastic container having a mouth, and supplies a medium gas into the plastic container. Supplying a medium gas G, which is an internal electrode for forming a barrier film on the inner surface of the plastic container by generating a discharge plasma on the inner surface of the plastic container by supplying high-frequency power to an external electrode provided outside A gas supply pipe 101 having a gas flow path 101a and a gas outlet 102 provided integrally with a gas supply pipe 101a through an adhesive 105 in a recess 101c formed at an end of the gas supply pipe. And an insulating member 103 having

Further, by caulking the open end 101d side of the cylindrical portion constituting the recess 101c, the adhesive 105 is held and the insulating member 103 integrated with the adhesive 105 is prevented from dropping. Yes.
Note that there is no edge during the caulking so as to prevent local plasma concentration.

  FIG. 4 shows an outline of an internal electrode for forming a barrier film according to the third embodiment of the present invention. As shown in FIG. 4, the barrier film-forming internal electrode 100-3 according to the present example is inserted into a plastic container having a mouth, and a medium gas is supplied into the plastic container. Supplying a medium gas G, which is an internal electrode for forming a barrier film on the inner surface of the plastic container by generating a discharge plasma on the inner surface of the plastic container by supplying high-frequency power to an external electrode provided outside A gas supply pipe 101 having a gas flow path 101a, and a bulging portion 103a fitted into a recess 101c formed at an end of the gas supply pipe 101, and a gas communicating with the gas flow path 101a And an insulating member 103 having an outlet 102.

The insulating member 103 has a bulging portion 103a, and the opening portion 101e side of the cylindrical portion constituting the concave portion 101c is caulked so as to hold the bulging portion 103a. Is prevented.
Note that there is no edge during the caulking so as to prevent local plasma concentration.

  FIG. 5 shows an outline of the barrier film forming internal electrode according to the fourth embodiment of the present invention. As shown in FIG. 5, the barrier film forming internal electrode 100-4 according to the present example is inserted into a plastic container having a mouth, supplies a medium gas into the plastic container, Supplying a medium gas G, which is an internal electrode for forming a barrier film on the inner surface of the plastic container by generating a discharge plasma on the inner surface of the plastic container by supplying high-frequency power to an external electrode provided outside A gas supply pipe 101 having a gas flow path 101a and having a tip part as a convex part 101d and an internal part having an opening 106a at the center part of the end face while being screwed into the convex part 101d so that the side faces are flush with each other. Engages with the hollow cap member 106 and the stepped portion 106b of the opening of the cap member 106, and engages with the inner surface of the cap member 106 to Comprising an insulating member 103 having a gas blow-out port 102 communicating with the passage 101a.

Further, the end 106c of the cap member 106 on the gas blowing side of the medium gas G is formed with an R at its corner to prevent local plasma concentration.
A seal member 121 such as a packing or a gasket is interposed between the convex portion 101d and the insulating member 103 so as to improve the gas sealability.

Since the cap member 106 is made of a metal material, the sealing performance is improved in the joining at the screwed portion with the gas supply pipe 101. Here, examples of the metal material of the cap member 106 include stainless steel, aluminum, tungsten, and nickel. Moreover, it is good also as a carbon material other than a metal material.
In this case, the cap member 106 and the gas supply pipe 101 are made of the same kind of material, so that the adhesiveness of the threaded portion caused by thermal stress relaxation due to thermal expansion can be maintained over a long period of time.

  The protruding amount d of the insulating material 103 is preferably about 1 to 10 mm, more preferably about 3 to 5 mm.

  As described above, when the insulating member 103 is screwed, the cap member 106 is used so as to be wrapped and held inside the cap member 106, so that the insulating member 103 can be positively prevented from falling and the cap can be prevented. The member 106 and the gas supply pipe 101 can be made of the same metal to improve the screwing property.

  FIG. 6 schematically shows an internal electrode for forming a barrier film according to the fifth embodiment of the present invention. As shown in FIG. 6, the barrier film forming internal electrode 100-5 according to the present example is inserted into a plastic container having a mouth, supplies a medium gas into the plastic container, Supplying a medium gas G, which is an internal electrode for forming a barrier film on the inner surface of the plastic container by generating a discharge plasma on the inner surface of the plastic container by supplying high-frequency power to an external electrode provided outside A gas supply pipe 101 having a gas flow path 100a and having a recess 101c having a space with a long tip in the axial direction; and screwed into an inner surface of the recess 101c of the gas supply pipe 101; An insulating member 103 having a substantially T-shaped longitudinal section having a gas blow-out port 102 communicating therewith, and a screwing portion 110b so that the side surface is flush with the concave portion 101c. While if is for and a cap member 110 of the real in which by forming a hole 110a over the axial direction of the outer periphery 102a and the fitting of the gas blow-out port 102 of the insulating member 103.

  In this embodiment, a spacer 112 is provided in the shaft internal space 111 formed when the screwing surface is formed on the inner surface of the recess 101c, and the head portion of the substantially T-shaped insulating member 103 is provided. 103a prevents intrusion into the inner back side of the recess 101c.

  Further, in the space portion 110c formed at the base end portion of the screwing portion 110b, the tip end portion of the recess portion 101c is caulked in the direction of the arrow X in the drawing so as to further prevent the insulating member 103 from falling. Also good.

  In this embodiment, the screwing area in the seal portion 120 is increased, and the sealing performance is further improved. Accordingly, the insulating member 103 is not dropped, and film formation can be performed stably over a long period of time.

  FIG. 7 shows an outline of an internal electrode for forming a barrier film according to the sixth embodiment of the present invention. As shown in FIG. 7, the barrier film-forming internal electrode 100-6 according to this example is similar to the barrier film-forming internal electrode 100-4 shown in Example 4 in that at least one protrusion 131a is formed on the internal electrode. The plasma generating part 131 having the above is provided integrally.

The material of the plasma generator 131 provided integrally is preferably made of a material having high thermal conductivity. Here, examples of the material having high thermal conductivity include metals such as tungsten (W) and nickel (Ni), carbon (C), and the like.
Thus, by providing the protrusion 131a positively, it is possible to stabilize the plasma generation location by plasma discharge.

The number of the protrusions 131a is not particularly limited as long as it is 1 or more.
The plasma generating part 131 is preferably installed at a location about 10 mm away from the tip of the insulating member 103. This is to prevent the insulating material from being chipped or cracked due to the local concentration of plasma if it is too close to the insulating member 103.
Further, in the gas supply pipe 101 in FIG. 1, it is preferable to avoid the position from the mouth portion to the shoulder portion of the container, and to provide the plasma generating portion 131 at either the central portion or the tip portion of the container. . This is for preventing positive generation of plasma at the mouth and shoulders and preventing color unevenness on the inner surface of the container.
Further, it is possible to form a uniform film by positively generating plasma in the central portion of the container.

FIG. 8 shows an outline of an internal electrode for forming a barrier film according to the seventh embodiment of the present invention.
In the sixth embodiment, the plasma generating portion 131 is provided with a protrusion, but in this embodiment, the hollow portion 131b is provided.
The depression 131b can positively specify the plasma generation location in the same manner as the protrusion 131a, and can obtain the same effect as in the seventh embodiment. It should be noted that the installation location of the recess 131b may be the same as the installation location of the protrusion 131a.

  As described above, the internal electrode for forming a barrier film according to the present invention prevents the insulating member of the internal electrode from falling in the film forming apparatus and can always stably form the barrier film of the container. It is suitable for use in the production of containers with good quality.

It is the schematic of the film-forming apparatus concerning a 1st Example. It is the schematic of the internal electrode for barrier film formation concerning a 1st Example. It is the schematic of the internal electrode for barrier film formation concerning a 2nd Example. It is the schematic of the internal electrode for barrier film formation concerning a 3rd Example. It is the schematic of the internal electrode for barrier film formation concerning a 4th Example. It is the schematic of the internal electrode for barrier film formation concerning a 5th Example. It is the schematic of the internal electrode for barrier film formation concerning a 6th Example. It is the schematic of the internal electrode for barrier film formation concerning a 7th Example. It is the schematic of the film-forming apparatus concerning a prior art.

Explanation of symbols

100-1 to 100-7 Internal electrode 101 Gas supply pipe 102 Gas outlet 103 Insulating member 104 Male part 105 Adhesive 106 Cap member 120 Seal part 131 Plasma generating part 11 Port part 12 Plastic container 13 External electrode 14 Exhaust pipe 16 Gas Outlet 17 Internal electrode 18 High frequency power supply G Medium gas

Claims (7)

Inserted inside a plastic container having a mouth, supplies a medium gas into the plastic container, and generates high-frequency power to an external electrode provided outside the plastic container, thereby generating discharge plasma on the inner surface of the plastic container An inner electrode for forming a barrier film on the inner surface of the plastic container,
A gas supply pipe having a gas flow path for supplying a medium gas and having a recess having a space with a long tip in the axial direction;
An insulating member screwed into the inner surface of the recess of the gas supply pipe and having a gas outlet that communicates with the gas flow path;
A solid cap member that is screwed with a screwed portion so that the side surface is flush with the recess, and has a hole extending in the axial direction that fits with the outer periphery of the gas outlet of the insulating member. An internal electrode for forming a barrier film. In claim 1 ,
An internal electrode for forming a barrier film, wherein the gas supply pipe is integrally provided with a plasma generating part having at least one protrusion or depression. In claim 2 ,
The internal electrode for forming a barrier film, wherein the plasma generating part is made of a material having high thermal conductivity. In claim 1 ,
An internal electrode for forming a barrier film, comprising a sealing member for sealing the screwed portion. In any one of Claim 1 thru | or 4 ,
The internal electrode for forming a barrier film, wherein the gas supply pipe is made of metal. It is provided with any one of a barrier-film forming internal electrodes of claims 1 to 5, the film forming apparatus characterized by comprising forming a barrier film on the inner surface of the plastic container. A film forming apparatus for applying a barrier film by discharge plasma to the inner surface of a plastic container having a mouth,
An external electrode having a size surrounding the outer periphery of the plastic container;
An exhaust pipe attached via an insulating member to an end face of the external electrode on the side where the mouth is located;
The outside to the plastic container in the electrode from the exhaust pipe side are inserted over substantially the entire length of the longitudinal of said plastic container, a barrier film of any one of claims 1 to 5 connected to the ground An internal electrode;
An exhaust device attached to the exhaust pipe;
A gas supply device for supplying a medium gas to the internal electrode;
A film forming apparatus comprising: a high-frequency power source connected to the external electrode.

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