Film-forming auxiliary tool, film-forming device, and method for manufacturing coated container

Abstract

The purpose of the present invention is to further improve the degree of freedom in the shape of a container that can secure a gas barrier property regardless of adjustment of the shape or the like of an external electrode, when forming a barrier film applied to the container by using a high-frequency electric field.　An auxiliary tool used for a film forming device that forms a film on an inner surface of a container is configured to be insertable into an external electrode that accommodates the container. The auxiliary tool comprises a dielectric part stacked on a conductor part. When the auxiliary tool is inserted into the external electrode, the dielectric part faces the outer surface of the container, and when the auxiliary tool is inserted into the external electrode, the dielectric part and the conductor part are disposed in this order from the container between the container and the external electrode.

Description

[Technical Field]

[0001] The present disclosure relates to an auxiliary tool used for forming a film on a container, an apparatus including the auxiliary tool, and a method for producing a container having a coating using the auxiliary tool. [Background technology]

[0002] Gas barrier properties have been imparted to resin containers by forming a thin film (barrier film). The barrier film has gas barrier properties that prevent gas permeation, and corresponds to a thin film of DLC (Diamond-like Carbon), for example. DLC films can be formed, for example, by plasma-enhanced chemical vapor deposition (PECVD) using a high-frequency electric field to decompose and ionize a source gas with plasma generated in a reduced-pressure space, and then causing the ions accelerated by the electric field to collide with the surface of the container (see Patent Document 1, etc.).

[0003] For example, when forming a barrier film on the inner surface of a container, the apparatus used to form such a barrier film includes an external electrode that is divided into chambers capable of accommodating the container, an internal electrode that is inserted into the inside of the container and also serves as an inlet pipe for the raw material gas, an exhaust device that exhausts air from inside the chamber, and a high-frequency power source.

[0004] Conventionally, major challenges for devices and methods for forming a barrier film have been to improve the gas barrier properties, as well as to suppress abnormal discharge in gaps between the divided surfaces of the external electrode and to achieve uniformity in the state (thickness, etc.) of the barrier film. In particular, when a container having a narrow neck relative to the body, such as a bottle-shaped container, is placed in a chamber consisting of an external electrode that is typically cylindrical, the state of the barrier film is likely to become non-uniform due to bias in electric flux density, making it difficult to achieve sufficient gas barrier properties.

[0005] As a basic measure for suppressing abnormal discharge and forming a uniform barrier film, a dielectric is disposed between the external electrode and the container, as described in Patent Documents 1 to 4. In Patent Documents 2 and 3, the region of the external electrode facing the neck of the container is made thicker to bring the neck and the external electrode closer together in order to improve gas barrier properties, and a dielectric layer of a constant thickness is superimposed on the inner periphery of the external electrode. In Patent Document 4, the dielectric is arranged along the surface of the container so as to fill the space between the external electrode and the container.

[0006] The orientation of the container during film formation may be upright or inverted. For example, as in Patent Documents 2 and 3, when an upright container is inserted neck-first into the opening of the external electrode and the opening is closed, the bottom of the container is supported by the bottom of the external electrode. As in Patent Document 4, when an inverted container is inserted neck-first into the opening of the external electrode and the opening is closed, the mouth of the container is supported by the bottom of the external electrode. When the entire container is housed in the chamber, the dielectric provided on the external electrode is positioned facing the body, neck, and bottom of the container.

[0007] When an alternating electric field is applied, a displacement current flows in the dielectric, so it is permissible to have a gap between the neck and the dielectric as in Patent Documents 2 and 3. However, in order to obtain sufficient gas barrier properties, it has conventionally been necessary to position the external electrode and the dielectric to some extent along the outer surface of the container.

[0008] Therefore, Patent Document 1 discloses a means capable of uniforming the voltage and improving the gas barrier properties without necessarily arranging the external electrode and the dielectric along the outer surface of the container. Patent Document 1 defines a "converted distance" obtained by dividing the thickness of the dielectric or gap between the external electrode and the container by the relative dielectric constant. As a means of uniforming the applied voltage, the material of the dielectric, the thickness of the dielectric and gap, and the shape of the external electrode are combined so that the total converted distance from the external electrode to the container is uniform throughout the container.

[0009] In this case, since it is not necessary to give the external electrode and the dielectric a shape similar to that of the container, a cylindrical external electrode and a cylindrical dielectric can basically be used for containers of different shapes. Therefore, it is not always necessary to replace the external electrode and the dielectric when changing the shape. Furthermore, when a cylindrical external electrode and a cylindrical dielectric are used, the container can be inserted from the bottom into the opening of the external electrode while the neck is held by the holder, without the container or the holder interfering with the dielectric or the external electrode. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 5355860 [Patent Document 2] Japanese Patent Application Publication No. 2019-065318 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-256708 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-046182 Summary of the Invention [Problem to be solved by the invention]

[0011] The technique of Patent Document 1 improves the degree of freedom in the shape of the container on which the film is formed, and therefore allows for various container shapes, such as containers with uneven bodies, while ensuring sufficient gas barrier properties by making the thickness of the barrier film uniform. However, in recent years, container shapes have become increasingly diverse, making it difficult to obtain sufficient gas barrier properties depending on the shape of the container.

[0012] For example, consider a case where a container with a neck extending over half of the container's height is placed inside a cylindrical external electrode, and a dielectric with a shape similar to that of the neck is placed between the external electrode and the container to form a barrier film on the container. A thick dielectric is placed between the external electrode and the neck, and the thick region of the dielectric extends over half of the container's height, just like the neck. In this case, even if the body region has good gas barrier properties, the neck region, which has relatively poor gas barrier properties, occupies up to half of the container's height. The energy of the high-frequency electric field is attenuated by the thick region of the dielectric facing the neck.

[0013] Here, the gas barrier property based on oxygen permeability corresponds to the sum of the gas barrier properties corresponding to the surface area of ​​each region when the container is divided into multiple regions. Measurements of the oxygen permeability of the container after film formation by the inventors of the present disclosure showed that the gas barrier property of the container exemplified above, i.e., the container in which the area ratio of the region with relatively poor gas barrier property to the entire container is too large, was insufficient.

[0014] In other words, depending on the shape of the container, even if the dielectric is given a shape similar to the shape of the container, it is not necessarily possible to achieve a sufficient level of gas barrier property for the container as a whole. If the external electrode is given a shape similar to the shape of the container in order to achieve this, it would be necessary to prepare an external electrode for each differently shaped container, and the external electrode would have to be replaced when the container is changed.

[0015] In light of the above, the present disclosure aims to further improve the degree of freedom in the shape of a container that ensures gas barrier properties when forming a barrier film on a container using a high-frequency electric field, without having to adjust the shape of an external electrode, etc. [Means for solving the problem]

[0016] A film formation auxiliary tool according to the present disclosure is used in a film formation apparatus that forms a film on the inner surface of a container. The auxiliary tool is configured to be insertable into the inside of an external electrode that houses the container. The auxiliary tool also includes a conductor portion and a dielectric portion laminated on the conductor portion. When the auxiliary tool is inserted into the inside of the external electrode, the dielectric portion faces the outer surface of the container. When the auxiliary tool is inserted into the external electrode, the dielectric portion and the conductor portion are arranged, in that order from the container side, between the container and the external electrode.

[0017] The film forming apparatus according to the present disclosure is an apparatus for forming a film on the inner surface of a container, and includes an external electrode configured to be able to accommodate the container, an internal electrode disposed inside the container, and the above-mentioned auxiliary tool.

[0018] The method for manufacturing a coated container according to the present disclosure is a method for manufacturing a container having a coating on its inner surface, and includes the steps of arranging the above-mentioned auxiliary tool around the container, housing the container and auxiliary tool inside an external electrode, evacuating the space in which the container is placed and introducing a gas containing the raw material of the film to be applied to the container, and applying an electric field between the external electrode and an internal electrode placed inside the container. [Effects of the Invention]

[0019] The film formation auxiliary tool of the present disclosure is a separate piece from the external electrode, configured to be insertable inside the external electrode, and includes a conductor portion and a dielectric portion. By using this film formation auxiliary tool, abnormal discharge is suppressed by the dielectric portion of the auxiliary tool, and it is possible to position the conductor portion close to an area of ​​the container that has poor gas barrier properties, even if the container has shape characteristics that make it difficult to ensure gas barrier properties. This is without changing the shape of the external electrode or the dielectric portion pre-assembled to the external electrode to match the container.

[0020] When the auxiliary tool is inserted inside the external electrode, the dielectric portion of the auxiliary tool facing the outer surface of the container and the conductive portion of the auxiliary tool are both positioned between the container and the external electrode. The auxiliary tool can be positioned around the container outside the external electrode, and the auxiliary tool can be inserted inside the external electrode together with the container. When a barrier film is formed on a container using an auxiliary tool, the distance from the conductive portion to the container is short, thereby improving the gas barrier properties in the region of the container where the auxiliary tool is placed. In addition, since the conductive portion of the auxiliary tool is placed between the container and the external electrode, the thickness of the dielectric between the container and the external electrode is reduced, thereby reducing dielectric loss, thereby improving the gas barrier properties in that region. This improves the gas barrier properties of the entire container, thereby ensuring gas barrier properties for containers of various shapes while suppressing abnormal discharge. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram illustrating an overall configuration of a film forming apparatus according to an embodiment of the present disclosure. [Figure 2] 2(a) is a cross-sectional view taken along line IIa-IIa in FIG. 1. FIG. 2(b) is a side view of a container on which a film is to be formed. [Figure 3] 10A and 10B are cross-sectional views showing modified examples of the cross-sectional shapes of the container and the assisting tool. [Figure 4] 2(a) to 2(d) are cross-sectional views of film-forming auxiliary tools that can be used to form a film on the container shown in FIG. [Figure 5] FIG. 1 is a flow diagram showing a process for manufacturing a container having a barrier film. [Figure 6] 10 is a diagram showing a state in which the container in an inverted position is handed over from the gripper of the transfer device to the gripper of the film forming device. FIG. [Figure 7] FIG. 10 is a diagram showing a state in which an assisting tool is arranged around the container. [Figure 8] 1(a) is a diagram showing a state in which the container and auxiliary tool are housed inside the external electrode and dielectric part, in which a film-forming process is carried out to form a barrier film on the inner surface of the container. [Figure 9] 10A and 10B are diagrams for explaining a film forming process on a container held in an upright position. [Figure 10]1(a) and 1(b) are diagrams for explaining why the use of an auxiliary tool improves the gas barrier properties, and 1(b) is a diagram showing a state in which the area of ​​the external electrode is conceptually expanded by using the auxiliary tool. [Figure 11] 1(a) is a diagram showing an example in which an auxiliary tool made of only a conductor is placed around the neck of a container instead of the auxiliary tool of the present disclosure, and FIG. 1(b) is a diagram showing a state in which part of the region of the dielectric part already provided on the external electrode shown in FIG. 1(a) is replaced with the auxiliary tool. [Figure 12] FIG. 1 is a diagram showing a typical beverage bottle for considering the relationship between the gas barrier properties of each region of the container and the gas barrier properties of the entire container. [Figure 13] 10A and 10B are diagrams for explaining the use of a dielectric portion and a gap to uniformize the voltage applied to the inner surface of the container. [Figure 14] 10A to 10C are diagrams for explaining the gas barrier properties when a film is formed using a dielectric auxiliary tool, and also showing an example of application of the auxiliary tool of the present disclosure to a container of a different shape. [Figure 15] FIG. 10 is a vertical cross-sectional view showing a modified example of the configuration of the assisting tool. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14. [Figure 17] FIG. 10 is a perspective view showing a modified example of the configuration of the assisting tool. [Figure 18] 10A and 10B are diagrams showing an example of application of an auxiliary tool to the bottom of a container. [Figure 19] 10A and 10B are vertical cross-sectional views showing modified examples relating to support of the container during film formation, support of the auxiliary tool, and division of the external electrodes, etc.; DETAILED DESCRIPTION OF THE INVENTION

[0022] An embodiment will now be described with reference to the accompanying drawings. 1 uses a high-frequency electric field to generate plasma in a reduced-pressure space, thereby forming a barrier film (not shown) on the inner surface of a resin container 2. The barrier film corresponds to a dense film capable of suppressing gas permeation, such as a carbon film including DLC ​​(Diamond-like Carbon) or a silica film.

[0023] The container 2 is formed into a bottle shape from a resin material such as polyethylene terephthalate (PET) or polypropylene (PP). This container 2 differs from a typical beverage bottle in that the dimension of a neck portion 22 with a smaller diameter is longer than the dimension of a cylindrical body portion 23 in the height direction along the axis A of the container 2. The container 2 can be divided into the following regions: a mouth portion 21 to which a lid (not shown) is attached after the container 2 is filled with the contents; a neck portion 22 continuous with the mouth portion 21; a body portion 23; and a bottom portion 24. The diameter of the neck portion 22 gradually increases from the mouth portion 21 toward the body portion 23.

[0024] The film forming apparatus 1 constitutes part of a production line for, for example, beverage products, detergents, pharmaceuticals, etc., and the container 2 is filled with a content that is mainly liquid. The barrier film applied to the container 2 provides the container 2 with gas barrier properties that inhibit gas permeation and gas adsorption to the container 2, thereby preserving the quality of the content filled in the container 2. The manner in which gas permeates the container 2 includes, for example, when a gas such as oxygen outside the container 2 permeates into the container 2, and when a gas such as carbon dioxide inside the container 2 permeates out of the container 2.

[0025] The film forming apparatus 1 can greatly improve the degree of freedom in the shape of the container 2 for which gas barrier properties are ensured by using the auxiliary tool 3 that is inserted inside the external electrode 10 during film formation. Therefore, the film forming apparatus 1 can achieve the required level of gas barrier properties not only for bottle containers with typical shapes, but also for containers 2 with unusual shapes. The shape of the container 2 shown in Fig. 1 is merely an example. As shown in Fig. 2(b), the film forming apparatus 1 is particularly effective for forming a barrier film on a container in which the height dimension L of the neck portion 22 or the small diameter portion adjacent to the neck portion 22 (a region having a smaller radial dimension than the body portion 23) is equal to or greater than 1 / 3 of the height dimension H of the entire container or equal to or greater than 1 / 2 of the effective height dimension h of the container.

[0026] [Configuration of Film Forming Apparatus] 1 and 2(a), the film forming apparatus 1 includes an external electrode 10 arranged outside the container 2, an internal electrode 11 arranged inside the container 2, a first dielectric member 12 provided inside the external electrode 10, an exhaust unit 13 that exhausts air from the space in which the container 2 is placed, a shielding member 14 that surrounds the external electrode 10, an auxiliary tool 3 (FIG. 4(a)) that includes a conductor part 31 and a second dielectric part 32, and a gripping tool 15 that grips the container 2. The film forming apparatus 1 performs a film forming process on the container 2 that is in an inverted position with its mouth 21 facing downward.

[0027] (external electrode) The external electrode 10 is made of a metal material such as copper or aluminum, or a conductive material such as carbon, and is formed in a shape that surrounds the space required for film formation in the container 2. The external electrode 10 is connected to a matching box 162 and a high-frequency power supply 17 through an electric wire that is connected to a connector 161.

[0028] The high-frequency power supply 17 (alternating electric field source) applies a high-frequency alternating electric field between the outer electrode 10 and the grounded inner electrode 11. The inner electrode 11 may be connected to a matching box 162 and the high-frequency power supply 17, and the outer electrode 10 may be grounded. The output of the high frequency power supply 17 is, for example, 100 to 1000 W, and the frequency band of the alternating electric field generated by the high frequency power supply 17 is, for example, 13.56 MHz to 100 MHz. It is also possible to adopt a frequency lower or higher than this frequency band.

[0029] The external electrode 10 accommodates the container 2, which is supplied to the film forming apparatus 1 by a transport device (not shown), and also functions as a chamber for maintaining a reduced pressure space inside. The external electrode 10, the first dielectric member 12, the auxiliary tool 3, and the container 2 are concentrically arranged as shown in FIG. 2(a).

[0030] The cross section of the container 2 is not limited to a circular shape, and may be substantially rectangular like the container 2r shown in Fig. 3. In that case, it is preferable that the shape of the auxiliary tool 3r is also given to have four flat surfaces facing the side surfaces 2r1 to 2r4, in accordance with the rectangular shape of the container 2r.

[0031] The external electrode 10 is composed of a cylindrical peripheral wall 101 and an upper wall 102 that is continuous with the upper end of the peripheral wall 101. The inner peripheral portion of the peripheral wall 101 is formed into a cylindrical surface. The external electrode 10 is configured to be movable in the vertical direction z relative to the position of the container 2 by a lifting mechanism (not shown). The assembly 19 is also configured to be movable in the vertical direction z relative to the position of the container 2 by a lifting mechanism (not shown). The assembly 19 includes insulating members 191 to 194, an exhaust section 13, and an internal electrode 11 supported by the insulating member 194. The opening 103 at the lower end of the external electrode 10 is opened and closed by raising and lowering the external electrode 10. Furthermore, the internal electrode 11 is inserted into the container 2 by raising and lowering the assembly 19.

[0032] 1, the container 2 is placed inside the external electrode 10 from the bottom 24, and the opening 103 is closed. When the assembly 19 is raised to the position shown in FIG. 1, the internal electrode 11 is inserted inside the container 2. The opening 103 is airtightly closed by insulating members 191, 192, etc. A sealing member (not shown) is disposed between the lower end of the external electrode 10 and the insulating member 191 as needed.

[0033] (internal electrode) The internal electrode 11 is made of a heat-resistant conductive material such as tungsten or stainless steel, and is inserted into the container 2 housed inside the external electrode 10. The internal electrode 11 is tubular and also serves as an introduction tube for gas containing the raw material for the barrier film. The raw material gas for the barrier film is introduced into the internal electrode 11 from a raw material gas supply source (not shown), filling the inside of the container 2. When the barrier film is a DLC film, the raw material gas is, for example, acetylene.

[0034] When a gas inlet part is provided in the film forming apparatus 1 separately from the internal electrode 11, the internal electrode 11 does not need to be tubular and may be, for example, rod-shaped. In this case, the gas inlet part for introducing the source gas into the inside of the container 2 does not need to be inserted inside the container 2. A cylindrical dielectric 110 is provided at the tip of the internal electrode 11 to prevent localized plasma concentration.

[0035] (First dielectric member) The first dielectric member 12 (existing dielectric member) is a dielectric member made of a dielectric material such as resin or ceramic. The first dielectric member 12 is provided inside the external electrode 10 to suppress abnormal discharge when an electric field is applied between the external electrode 10 and the internal electrode 11 and to form a uniform barrier film. Unlike the auxiliary tool 3, the first dielectric member 12 is provided in advance on the external electrode 10 before the coating container is manufactured by the film-forming device 1.

[0036] Similar to the external electrode 10, the first dielectric member 12 also comprises a cylindrical peripheral wall 121 and an upper wall 122 continuous with the upper end of the peripheral wall 121. The inner peripheral portion of the peripheral wall 121 is formed into a cylindrical surface. Since the inner surface of the external electrode 10 is covered with the first dielectric member 12, abnormal discharges resulting from localized spikes in energy levels caused by electrons flying out of the external electrode 10 when a high-frequency electric field is applied are suppressed.

[0037] Even if the first dielectric member 12 is present between the external electrode 10 and the container 2, application of an alternating electric field causes a displacement current to flow in the first dielectric member 12. Similarly, a displacement current also flows in the container 2, which is a dielectric, so that a high-frequency electric field can be applied between the external electrode 10 and the internal electrode 11 via the first dielectric member 12 and the container 2 to generate plasma.

[0038] The first dielectric member 12 can be made of an appropriate material having dielectric properties. Due to the dielectric properties, the first dielectric member 12 functions as an insulator, i.e., no current flows through it when a direct current electric field is applied, and a displacement current flows through it when an alternating electric field is applied. The first dielectric member 12 is preferably made of a material that has low dielectric loss, particularly in a high-frequency electric field, and high heat resistance, flame retardancy, and mechanical strength. For this reason, for example, resin materials such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), rigid vinyl chloride, polycarbonate, and polyether ether ketone (PEEK), or ceramic materials such as aluminum oxide (alumina) and steatite can be used. The first dielectric member 12 of this embodiment is made of PTFE.

[0039] When the container 2 is housed inside the external electrode 10, the first dielectric member 12 faces the body 23 and bottom 24 of the container 2. A gap is permitted between the peripheral wall 121 and the body 23, and a gap is permitted between the top wall 122 and the bottom 24. The dimensions of these gaps vary depending on the size and shape of the container 2.

[0040] (Exhaust section) The exhaust unit 13 is insulated from the external electrode 10 by insulating members 191, 192, etc., and is connected to a vacuum suction device 18 equipped with a vacuum pump, a vacuum tank, etc. With the opening 103 of the external electrode 10 closed, the source gas is blown out from the internal electrode 11 while exhausting the space inside the external electrode 10 through the flow path 13A of the exhaust unit 13, thereby creating a space inside and around the container 2 that is depressurized to a predetermined vacuum level. The pressure in the depressurized space is, for example, 0.1 to 1 Torr.

[0041] (Shielding material) The shielding member 14 functions as an electromagnetic shield to prevent electromagnetic wave radiation and as a high-frequency earth. The shielding member 14 is formed, for example, in a cylindrical shape from a conductive material such as aluminum, stainless steel, copper, or brass. The shielding member 14 covers the entire external electrode 10 while being insulated from the external electrode 10 and is grounded. The shielding member 14 is supported by the external electrode 10 via an insulating member 141 and moves up and down together with the external electrode 10. The shield member 14 may be configured as a chamber that provides a reduced pressure space around the container 2 instead of the external electrode 10 .

[0042] (gripping tool) The gripper 15 receives the container 2 from the gripper Gr (FIG. 6) of a transport device (not shown), and supports the container 2 in the space inside the external electrode 10 while a film formation process is performed on the container 2. The gripper 15 includes a gripper 151 that grips the neck portion 22 of the container 2, and a support member 152 that supports the gripper 151 and passes through the insulating member 193. The assembly 19 described above is raised and lowered relative to the gripper 15. In order to avoid localized plasma concentration in the space where the film formation process is performed, the gripper 151 is made of a dielectric material such as a resin material. The gripper 151 has a pair of gripping claws (not shown) that are configured to be able to open and close.

[0043] The container 2 is supported by the gripper 151 via a flange of the neck portion 22 (not shown). The auxiliary tool 3 is arranged around the container 2 supported by the gripper 151. The gripper 151 is configured so that the auxiliary tool 3 can be attached thereto.

[0044] [Configuration of film formation auxiliary tool] Next, the configuration of the auxiliary tool 3 including the conductor portion 31 and the second dielectric portion 32 will be described. The auxiliary tool 3 is disposed between the external electrode 10 and the container 2 during the film formation process, thereby providing the container 2 with sufficient gas barrier properties. The auxiliary tool 3 is inserted inside the external electrode 10 while being disposed around the container 2. The auxiliary tool 3 is attached to the gripper 151 so as to protrude upward from the gripper 151. Because the auxiliary tool 3 is supported by the gripper 151, when the container 2 held by the gripper 151 is accommodated inside the external electrode 10, the auxiliary tool 3 is also accommodated inside the external electrode 10 together with the container 2.

[0045] 1, the auxiliary tool 3 is disposed between the neck 22 of the container 2 and the first dielectric member 12. The auxiliary tool 3 is preferably formed in a shape that follows the shape of the curved neck 22 in a side view and the shape of the inner periphery of the first dielectric member 12, and generally fills the gap that is formed between the neck 22 and the first dielectric member 12 when the auxiliary tool 3 is not disposed. Therefore, the auxiliary tool 3 has an opposing surface 3A that is curved in a vertical cross section and faces the neck 22, and a back surface 3B that is linear in a vertical cross section and faces the first dielectric member 12.

[0046] The auxiliary tool 3 is generally cylindrical, and its inner periphery is given a shape that is suited to the outer shape of the container 2 for a particular product. The shape of the auxiliary tool 3 does not need to strictly correspond to the shape of the neck portion 22. The existence of gaps is permitted between the auxiliary tool 3 and the neck portion 22, and between the auxiliary tool 3 and the first dielectric member 12.

[0047] When the auxiliary tool 3 is arranged around the container 2, the back surface 3B of the auxiliary tool 3 is located at the same position as the outer peripheral surface of the body 23 of the container 2 or is located radially inward of that position of the container 2. As shown in Figure 7, when the container 2 and auxiliary tool 3 are projected in the vertical direction z toward the external electrode 10, the external electrode 10 and the first dielectric member 12 are not present within a projection area R1. Therefore, when the external electrode 10 is lowered to accommodate the container 2 inside the external electrode 10, the auxiliary tool 3 is inserted inside the external electrode 10 without interfering with the external electrode 10 or the first dielectric member 12.

[0048] The auxiliary tool 3 includes a massive conductor portion 31 and a second dielectric portion 32 as a coating covering the surface of the conductor portion 31, as shown in FIG. 4(a), for example. The volume ratio of the conductor portion 31 to the entire auxiliary tool 3 is approximately 100%.

[0049] The second dielectric portion 32 shown in FIG. 4(a) is provided over the entire surface of the first conductor portion 31. The second dielectric portion 32 has a first region 321 forming a facing surface 3A facing the container 2, a second region 322 forming a back surface 3B facing the external electrode 10, and a third region 323 facing the gripper 151. Although not shown in FIG. 4(a), the second dielectric portion 32 has fourth regions 324 on both side surfaces 3C in the circumferential direction CD, as shown in FIG. 2(a). Note that while FIG. 2(a) shows the fourth region 324 only for the segment 301, the segments 302 to 304 also have the fourth region 324. The second dielectric portion 32 includes the first region 321, the second region 322, the third region 323, and the fourth region 324, thereby covering the entire surface of the first conductor portion 31.

[0050] When the auxiliary tool 3 is inserted inside the external electrode 10, the relationship between the second dielectric portion 32 and the conductor portion 31 and the external electrode 10 and the first dielectric member 12 is as follows. The first region 321 of the second dielectric portion 32 faces the outer surface of the neck portion 22 of the container 2, and the second region 322 of the second dielectric portion 32 faces the peripheral wall 101 of the external electrode 10. The peripheral wall 121 of the first dielectric member 12 is interposed between the second region 322 and the peripheral wall 101. The conductor portion 31 faces the neck portion 22 of the container 2, with the first region 321 of the second dielectric portion 32 therebetween. The conductor portion 31 also faces the peripheral wall 121 of the first dielectric member 12, with the second region 322 of the second dielectric portion 32 therebetween.

[0051] The conductor portion 31 is made of a metal material such as aluminum, an aluminum alloy, copper, or a copper alloy, or a conductive material such as carbon. The second dielectric portion 32 is made of a dielectric material such as resin or ceramic. The second dielectric portion 32 can be made of, for example, the above-mentioned materials that can be used for the first dielectric member 12. The second dielectric portion 32 of this embodiment is made of PTFE, similar to the first dielectric member 12. The material of the first dielectric member 12 and the material of the second dielectric portion 32 may be different.

[0052] The auxiliary tool 3 is produced, for example, by applying a PTFE coating as the second dielectric portion 32 to the surface of the first conductor portion 31, which is made of aluminum and formed by cutting or the like. This coating is performed by using a spray gun, electrostatic powder coating machine, or the like to attach PTFE powder to the surface of the first conductor portion 31, and then forming a film on the surface of the first conductor portion 31 with the PTFE softened by heat treatment. The second dielectric portion 32 is formed to a substantially uniform thickness. The film thickness of the second dielectric portion 32 is, for example, 10 to 150 μm, and preferably about 30 to 70 μm.

[0053] Instead of coating with PTFE, the aluminum conductor portion 31 can be anodized. By anodizing, an aluminum oxide coating is formed on the surface of the conductor portion 31, and aluminum oxide is a dielectric. The aluminum oxide coating corresponds to the second dielectric portion 32.

[0054] As shown in FIG. 2(a), the auxiliary tool 3 is made up of two or more segments 301-304 arranged around the container 2. In other words, the auxiliary tool 3 is divided into n (n≦2) segments in the circumferential direction of the container 2. The auxiliary tool 3 in FIG. 2(a) is divided into four segments, each with a central angle of 90°. The auxiliary tool 3 does not necessarily have to be divided at equal angles. It is preferable that the segments 301-304 are arranged to surround the entire circumference of the container 2. Each of the segments 301 to 304 can be produced by, for example, applying a PTFE coating as the second dielectric portion 32 to the surface of a first conductive portion 31 made of aluminum that has been formed by cutting or the like.

[0055] By dividing the container 2 into a plurality of segments 301 to 304, the assisting tool 3 can be placed around the container 2 without having to transfer the container 2 from the gripper 151 to another holding mechanism. In this embodiment, the segment 302, which is separated from the other segments 301, 303, and 304 when the container 2 is transferred from the gripper Gr to the gripper 151, is assembled to the assembly 19, which serves as a support for supporting the internal electrode 11, via an insulating member 195. The segments 301, 303, and 304 are assembled to the gripper 151. When the container 2 is received by the gripper 151 from the gripper Gr, the segment 302 (separation segment) is retracted to a position away from the gripper Gr 15 and the container 2 (see FIG. 6). After the container 2 is received by the gripper 151, when the assembly 19 is moved toward the container 2 (FIGS. 7 and 8(a)), all of the segments 301 to 304 are arranged around the container 2. In the example in which the auxiliary tool 3 is arranged around the container 2 as described above, the segments 301, 303, and 304 may be combined to form an integral part. In other words, the auxiliary tool 3 may be divided into two segments: a segment in which the segments 301, 303, and 304 are integrated, and the segment 302.

[0056] If it is possible to arrange the auxiliary tool 3 around the neck 22 of the container 2, the auxiliary tool 3 can be formed into a circumferentially continuous, one-piece cylindrical shape without being divided in the circumferential direction. For example, when the container 2 in an inverted position is inserted from above into the cylindrical auxiliary tool 3, the auxiliary tool 3 is arranged around the neck 22.

[0057] The auxiliary tool 3 shown in Fig. 4(a) is disposed over the entire length of the neck 22 in the height direction of the container 2, but the auxiliary tool 3 in the present disclosure is not limited to this. As shown in Fig. 4(b), the auxiliary tool 3 may have a shape in which the side closer to the body 23 is missing compared to the shape shown in Fig. 4(a), as in the auxiliary tool 3-1.

[0058] When the film forming apparatus 1 forms barrier films on containers 2 of different shapes corresponding to a plurality of types of products, it is preferable to prepare a plurality of types of film forming auxiliary tools suitable for each of the different container shapes. In this case, the film forming auxiliary tool is selected according to the container shape of the product to be manufactured. Therefore, it is preferable that the auxiliary tool 3 is detachably attached to the gripper 151 and the insulating member 195. The auxiliary tool 3 is not necessarily used only for the film formation process on the container 2 of a single product, but can also be used for the film formation process on the containers of two or more different products. For example, the assisting tool 3-2 shown in FIG. 4(c) can be used for both a container having a neck portion 22 shown by a two-dot chain line and a container having a neck portion 22 shown by a one-dot chain line.

[0059] In order to suppress abnormal discharge, it is sufficient that the second dielectric portion 32 has at least the first region 321 facing the neck portion 22 of the container 2. For example, as in the auxiliary tool 3-3 shown in Fig. 4(d), the second dielectric portion 32 has only the first region 321 and the third region 323, and therefore the back surface 31B of the conductor portion 31 may be exposed.

[0060] In this embodiment, when the auxiliary device 3 is placed in the film formation chamber DC of the film formation apparatus 1, the external electrode 10, the first dielectric member 12, the auxiliary device 3 and the container 2 are arranged in this order in the radial direction rd from the external electrode 10 side toward the axis A of the film formation chamber DC where the internal electrode 11 is placed. Focus is now placed on the conductor portion 31 and the second dielectric portion 32 of the auxiliary tool 3. In the case of the auxiliary tool 3 shown in FIG. 4(a), the external electrode 10, the first dielectric member 12, the second dielectric portion 32 (second region 322), the conductor portion 31, and the second dielectric portion 32 (first region 321) are similarly arranged in this order. In the case of the auxiliary tool 3-3 shown in FIG. 4(a), the external electrode 10, the first dielectric member 12, the conductor portion 31, and the second dielectric portion 31 (first region 321) are similarly arranged in this order. While abnormal discharge can be suppressed by adopting at least the arrangement of the auxiliary tool 3-3, the effect of suppressing abnormal discharge is greater when the arrangement of the auxiliary tool 3 is adopted.

[0061] The film deposition auxiliary tool 3, which is a combination of the segments 301 to 304, comprises a cylindrical conductor portion 31 made of a conductive material and having an inner circumferential surface IS and an outer circumferential surface OS (FIG. 2(a)), and a dielectric portion 32 (first region 321) that covers at least the inner circumferential surface IS of the conductor portion 31. If the second region 322 is provided, the dielectric portion 32 will also be provided on the outer circumferential surface OS.

[0062] [Manufacturing procedure for coated containers] An example of a procedure for manufacturing a container 2c provided with a barrier film will be described with reference to FIGS. As shown in FIG. 6, a series of processes from receiving the container 2 (S01) to discharging the coated container 2c with the barrier film applied thereto from the film forming apparatus 1 (S07) as shown in FIG. 8(b) is repeated at a predetermined cycle time.

[0063] As shown in FIG. 6, a container 2 supplied to the film forming apparatus 1 by a gripper Gr of a transport device (not shown) is received by the gripper 15 (container supply step S01). At this time, only segments 301, 303, and 304 attached to the gripper 151 are arranged around the neck 22 of the container 2, with the segment 302 retracted below the container 2. Therefore, the gap between the pair of gripping jaws (not shown) of the gripper 151 is open over the central angle (90°) of the segment 302 that is not present around the container 2. At this time, the neck 22 of the container 2 is inserted between the pair of gripping jaws through a gap present at the position of the segment 302 shown in FIG. 2. When the pair of gripping jaws closes due to a drive mechanism (not shown), the neck 22 is gripped by the gripper 151. In other words, the phases and central angles of the segments 301 to 304 around the container 2 are appropriately determined, enabling the container 2 to be handed over from the gripper Gr to the gripper 151.

[0064] 7, the external electrode 10 is lowered toward the container 2, thereby housing the container 2 in the space formed between the external electrode 10 and the assembly 19 (container housing step S02). In parallel with this, the assembly 19 is raised toward the container 2, thereby inserting the internal electrode 11 into the container 2 (internal electrode insertion step / auxiliary tool arrangement step S03). As the internal electrode 11 is inserted, the segment 302 supported by the assembly 19 together with the internal electrode 11 rises and is inserted into the circumferential gap between the segment 301 and the segment 303 . When the opening 103 of the external electrode 10 is closed by raising the assembly 19, all of the segments 301 to 304 are arranged around the neck 22 of the container 2 (FIG. 8(a)).

[0065] 8(a), a film formation process is performed on the container 2 housed inside the external electrode 10 according to the following procedure. When the film formation process is performed on the container 2 in an inverted position, dust and the like that have not accumulated in the container 2 tend to be expelled from the mouth 21 of the container 2 by its own weight. The space between the external electrode 10 and the assembly 19 is evacuated through the exhaust unit 13, and the source gas is introduced into the container 2 through the internal electrode 11 (evacuation and source gas introduction step S04).

[0066] With the chamber space decompressed to a predetermined vacuum level by evacuation, an alternating electric field is applied between the external electrode 10 and the internal electrode 11 by the high-frequency power supply 17 for a predetermined time (for example, several seconds) (electric field application step S05). The application of the high-frequency electric field generates a discharge from the external electrode 10 toward the internal electrode 11. The discharge generates plasma, which decomposes and ionizes the source gas, and the ions accelerated by the electric field collide with the inner surface of the container 2, forming a barrier film. By disposing the first dielectric member 12 and the second dielectric portion 32 between the external electrode 10 and the internal electrode 11, the occurrence of abnormal discharge that may cause damage to the barrier film and the container 2 is suppressed.

[0067] When the film formation in the container 2 is completed, air is introduced into the chamber space through a path not shown (opening to the atmosphere step S06). 8(b), the outer electrode 10 is raised to open the opening 103, and the assembly 19 is lowered to remove the inner electrode 11 from the coating container 2c. At least one of the segments 301 to 304 is then retracted from the neck 22, making it possible to eject the coating container 2c. The coating container 2c is then handed over from the gripper 15 to another gripper (not shown) and ejected from the film forming apparatus 1 (container ejection step S07). This completes the production of the coated container 2c having a barrier film.

[0068] It is also possible to perform a film formation process on a container 2 held in an upright position as shown in Fig. 9. The film formation apparatus 1-2 shown in Fig. 9 has a configuration that is upside down compared to the film formation apparatus 1 shown in Fig. 1. Of the segments 301 to 304, segments 301, 303, and 304 are supported by the gripper 151 in a state in which they are suspended downward from the gripper 151. The remaining segment 302 is similarly supported by the assembly 19. This segment 302 is separated from the segments 301, 303, and 304 until the internal electrode 11 is inserted into the container 2.

[0069] [Function of film formation auxiliary tool] The function of the assisting tool 3 will be described with reference to FIGS. 10(a) and 10(b). The auxiliary tool 3 is separate from the external electrode 10 and the first dielectric member 12 already attached to the external electrode 10. Therefore, it is possible to place the auxiliary tool 3 inside the external electrode 10 and the first dielectric member 12 in the film formation chamber DC around the neck portion 22, which is thinner than the body portion 23 of the container 2. The auxiliary tool 3 placed around the neck portion 22 is inserted along the vertical direction z into the inside of the external electrode 10 and the first dielectric member 12, both of which are cylindrical, together with the container 2, without interfering with the external electrode 10 or the first dielectric member 12.

[0070] At this time, in the radial direction rd, the area between the container 2 and the first dielectric member 12 is occupied by the conductor portion 31, except for the second dielectric portion 32 on the surface of the auxiliary tool 3. In this case, it is as if the conductor portion 31 constitutes part of the external electrode 10, and as shown in FIG. 10(b), the thickness of the external electrode 10x increases toward the inside in the radial direction rd, which is almost equivalent to the external electrode 10x approaching the periphery of the container 2. In other words, by using the auxiliary tool 3, the conductive area of ​​the external electrode 10 (FIG. 10(a)) can be effectively expanded to the conductive area of ​​the external electrode 10x.

[0071] Even if the auxiliary tool 3 is arranged around the container 2 and the area of ​​the external electrode 10 is expanded to a position close to the container 2, the distance from the conductor (the conductor portion 31, the external electrode 10x) to the container 2 is shorter than the distance from the inner periphery of the first dielectric member 12 to the container 2. Therefore, in either case, this contributes to improving the gas barrier properties. However, as shown in Fig. 10(b), if the area of ​​the external electrode 10x is expanded inward, then even if an attempt is made to insert the container 2 into the external electrode 10x from the bottom 24 side, the container 2 will interfere with the external electrode 10x and the first dielectric member 12. Therefore, since the container 2 cannot be accommodated inside the external electrode 10x, a film formation process using the external electrode 10x will not be possible.

[0072] As shown in Fig. 11(a), instead of the auxiliary tool 3, an auxiliary tool J1 having the same shape and dimensions as the auxiliary tool 3 but consisting only of a conductor separate from the external electrode 10 is placed around the neck portion 22. In this case, it is possible to house the container 2 and the auxiliary tool J1 inside the external electrode 10. However, because the surface of the auxiliary tool J1 is not covered with a dielectric, electrons may fly out of the auxiliary tool J1 when a high-frequency electric field is applied, which may cause abnormal discharge.

[0073] 11(b), the area may be expanded radially outward from the container 2. Since the outer diameter of the auxiliary tool 3x is smaller than the inner diameter of the external electrode 10, the container 2 and the auxiliary tool 3x can be accommodated inside the external electrode 10 without any problems. 11(b), the area of ​​the assisting tool 3x may be expanded beyond the position of the shoulder 28 of the container 2. At this time, the first dielectric member 12 faces the bottom 24 of the container 2.

[0074] When auxiliary tool 3 is used, the distance from conductive part 31 to container 2 is short, which increases the energy density of electrons, ions, and radicals in the plasma, and ions and radicals derived from the source gas collide with sufficient energy against the inner surface of container 2. As a result, the quality of the barrier film formed on the inner surface of neck 22 improves and the thickness of the barrier film increases, improving the gas barrier properties of neck 22 where auxiliary tool 3 is placed. Furthermore, the presence of the second dielectric portion 32 in the auxiliary device 3 makes it possible to suppress the occurrence of abnormal discharge caused by electrons emitted from the external electrode 10 escaping into the chamber space. The second dielectric portion 32 is made of a material with low dielectric loss at high frequencies and is a thin coating, so it hardly attenuates the energy of the high-frequency electric field.

[0075] The case where a barrier film is formed on the container 2 without using the auxiliary tool 3 will be described below, also referring to the basic concept of gas barrier properties. If auxiliary tool 3 is not used to form the film on container 2, and a large gap is therefore formed between neck 22 and first dielectric member 12, the gas barrier properties of the barrier film formed on container 2 in this state will be insufficient relative to the required level. Even if an auxiliary tool having the same shape as auxiliary tool 3 but made of a dielectric material separate from first dielectric member 12 is placed around neck 22 instead of auxiliary tool 3, the gas barrier properties will not reach the required level due to dielectric loss caused by the thick dielectric. This is confirmed by a comparative example of the film formation test results described later.

[0076] The reason why the container 2 of this embodiment is disadvantageous from the viewpoint of gas barrier properties is that the length of the thin neck portion 22 is too long compared to the container 2b, which is a typical resin bottle for beverages shown in Fig. 12. The height direction length L (Fig. 2(b)) of the neck portion 22 of the container 2 amounts to more than half the height H of the entire container 2. Furthermore, the height direction length L of the neck portion 22 approaches approximately two-thirds of the effective film formation height h located in the reduced pressure space above the gripper 151. The gas barrier property decreases as the distance from the external electrode 10 to the container 2 increases. The gas barrier property of the neck portion 22, which is the farthest from the inner peripheral surface of the cylindrical external electrode 10, is inferior to the gas barrier property of the body portion 23, which is the closest to the inner peripheral surface of the external electrode 10, even if a dielectric spacer is arranged around the neck portion 22.

[0077] As described above, the neck 22 of the container 2 occupies more than half of the height H of the container 2. When the neck 22 occupies such a wide area of ​​the container 2, even if the body 23, which has good gas barrier properties, is present, the gas barrier properties of the container 2, which is the sum of the gas barrier properties of each region, are reduced. In other words, in order to improve the gas barrier properties of the container 2, it is important to improve the gas barrier properties of the region with poor gas barrier properties, which has a large ratio of surface area to the entire container. A calculation example to confirm this will be described later.

[0078] (Gas barrier properties) The concept of gas barrier property will now be explained. "Gas barrier property" is typically evaluated by the oxygen permeability per container 2. The oxygen permeability is typically measured using the MOCON method (oxygen permeability measurement). When the oxygen permeability per unit area of ​​the container 2 is uniform, the oxygen permeability of the entire container 2 is expressed by the following formula. [Oxygen permeability per unit area] x [surface area of ​​container]

[0079] When the oxygen permeability differs depending on the region of the container 2, the oxygen permeability B of the entire container 2 can be expressed as the sum of the oxygen permeabilities of the respective regions, as shown in the following formula (1). In formula (1), b iis the oxygen permeability in region i, S i is the surface area of ​​region i.

[0080]

number

[0081] Referring to a typical beverage container 2b shown in FIG. 12, the relationship between the gas barrier properties of each region of the container 2b and the gas barrier properties of the container 2b as a whole will be considered. If the oxygen permeability of the uncoated container 2b is uniform throughout the container 2b, the oxygen permeability b per unit area of ​​the container 2b can be expressed by the following formula (2): In formula (2), S and B have the following meanings. S: total surface area of ​​container 2b B: Oxygen permeability of the entire container 2b before the film formation (before the barrier film formation)

[0082]

number

[0083] As shown in FIG. 12, the bottle 2b is divided into three regions 201 to 203. Here, if the surface areas of the regions 201 to 203 of the container 2b are S1, S2, and S3, respectively, then the surface areas can be expressed as in the following formula (3).

[0084]

number

[0085] The surface areas of the regions 201, 202, and 203 are, for example, Assume that S1 = 0.3S, S2 = 0.5S, and S3 = 0.2S. The total surface area of ​​the surface area S1 of the region 201 and the surface area S3 of the region 203 corresponds to half of the entire surface area of ​​the container 2b. The oxygen permeabilities of the regions 201 to 203 after the barrier film is formed are denoted by b1, b2, and b3. If the oxygen permeability of the entire container 2b after the barrier film is formed is B', it can be expressed by the following formula (4).

[0086]

number

[0087] The BIF (Barrier Improvement Factor) at this time is expressed by the following formula (5): BIF corresponds to "gas barrier property."

[0088]

number

[0089] To confirm the relationship between the quality of the gas barrier properties of each region of the container and the area ratio, as shown in the table below, we assumed CASE 1 and CASE 2 and calculated the change in the overall oxygen permeability when the oxygen permeability of each of regions 201 to 203 changed. Table 1 shows an example. The calculation was performed assuming S=1 and B=1.

[0090] [Table 1]

[0091] From CASE 1 and CASE 2, it can be said that even if the gas barrier properties of the region 202 with the best gas barrier properties are slightly deteriorated, the gas barrier properties of the regions 201 and 202, which have a large surface area that together accounts for half of the entire surface area of ​​the container 2b and have poor gas barrier properties, can be improved, thereby improving the gas barrier properties of the entire container 2.

[0092] [Using the technology described in Patent No. 5355860] Incidentally, the present disclosure can utilize a means for uniforming the voltage applied to the inner surface of the container 2 based on the description in Japanese Patent No. 5355860. As shown schematically in FIG. 13, a dielectric member 4 and a gap 5 exist between the container 2 and the external electrode 10. The dielectric member 4 corresponds to the first dielectric member 12 and the second dielectric portion 32 of the auxiliary tool 3 at point B on the vertical cross section of the container 2 (FIG. 10(a)). The dielectric member 4 corresponds to the first dielectric member 12 at point C. Furthermore, the dielectric member 4 corresponds to the second dielectric portion 32 of the auxiliary tool 3x at point D in FIG. 11(b).

[0093] For example, at point B (FIG. 10(a)), gap 5 corresponds to the gap between auxiliary tool 3 and neck portion 22 and the gap between auxiliary tool 3 and first dielectric member 12. At point C, gap 5 corresponds to the gap between body portion 23 and first dielectric member 12. Furthermore, at point D in FIG. 11(b), gap 5 corresponds to the gap between neck portion 22 and auxiliary tool 3.

[0094] In Japanese Patent No. 5355860, the voltage applied to the inner surface of the container 2 is made uniform by using a dielectric member 4 and a gap 5. The gist of this is that the thickness (d i ) to the relative permittivity (ε i ) divided by the converted distance (d i / ε i The material of the dielectric member 4, the thickness of the dielectric member 4 and the gap 5, and the shape of the external electrode 10 are combined so that the sum of the distances from the inner surface 10A of the external electrode 10 to the inner surface 20 of the container 2 is uniform throughout the container 2. By doing so, the following condition A) is satisfied.

[0095] Condition A) The thickness (d i ) to the relative permittivity (ε i ) divided by the converted distance (d i / ε i ) for the sum of the values ​​at each point from the inner surface 10A of the external electrode 10 to the inner surface 20 of the container 2, the value obtained by dividing the standard deviation of the sum of the values ​​at each point over the entire container 2 by the average value is 0.75 or less.

[0096] Next, based on the above summary, Patent No. 5355860 presents the following condition B): Condition B) The thickness (d i ) to the relative permittivity (ε i The ratio of the maximum value Gmax to the minimum value Gmin (Gmax / Gmin) of the converted distance G is 11 or less.

[0097] Furthermore, from the above summary, Patent No. 5355860 presents the following condition C): Condition C) The average thickness / relative dielectric constant of the dielectric member 4 is in the range of 0.95 to 3.8.

[0098] 14, calculation results are shown for the container 2e, the auxiliary tool J2 made of a dielectric, and the film forming apparatus 1 under the above conditions A to C. The dielectric member 4 in FIG. 13 corresponds to the first dielectric member 12 and the auxiliary tool J2 at point E in FIG.

[0099] Like the neck portion 22 of the container 2 of this embodiment, the container 2e has a small diameter portion 26 that is smaller in diameter than the body portion 23 and is long in the height direction, and a neck portion 27 that is gripped by the gripper 151. The length L of the small diameter portion 26 in the height direction is approximately half the effective film formation height h. The small diameter portion 26 is located between the neck portion 27 and the body portion 23 and has a constant diameter Dmin. The diameter Dmin is smaller than the maximum diameter Dmax of the container 2e by 20 mm or more. The auxiliary tool J2 is made of a dielectric material throughout. Both the inner and outer peripheral parts of the auxiliary tool J2 are cylindrical, and the auxiliary tool J2 is disposed between the small diameter part 26 and the first dielectric material 12 over a length L.

[0100] When the value of condition A) was calculated for the container 2e, the auxiliary tool J2, and the film forming apparatus 1, it was found to be 0.20, which satisfies condition A). Furthermore, when Gmax / Gmin was calculated for the converted distance G, it was found to be 2.2, which satisfies condition B). Furthermore, when the average thickness / relative dielectric constant of the dielectric member 4 was calculated, it was found to be 5.8. This value does not satisfy condition C).

[0101] The reason why the container 2e does not satisfy condition C) is that, as mentioned above, the gas barrier property is the sum of the gas barrier properties of each part of the container. Although the container 2e has good gas barrier property over the range 231 of the maximum outer diameter of the body 23, this range 231 is only about 1 / 5 of the effective film formation height h of the container 2e. The remaining part of the container 2e has poorer gas barrier property than the range 231. Of the remaining portions, the length L of the small diameter portion 26, which has the largest diameter difference from the range 231 and therefore the weakest barrier property, accounts for approximately half of the effective height h.

[0102] In addition, since the external electrode 10 is formed in a cylindrical shape over the entire length in the vertical direction z, the cylindrical inner surface 10A is far from the outer surface 26A of the small diameter portion 26. Therefore, the first dielectric member 12 and the auxiliary tool J2 are disposed as the thick dielectric member 4 between the small diameter portion 26 and the first dielectric member 12. That is, the region of the container 2e where sufficient gas barrier properties can be obtained is only about half at most, and the dielectric member 4 is too thick, resulting in large dielectric loss, so the gas barrier properties of the container 2e are insufficient.

[0103] From the above-mentioned condition B), in order to improve the gas barrier property, it is necessary to reduce the converted distance G related to the dielectric member 4 (first dielectric member 12 and auxiliary tool J2) and the gap in the range R2 from the inner surface 10A of the external electrode 10 to the outer surface 26A of the small diameter portion 26. Furthermore, if there is a large difference between the maximum and minimum diameters in the effective film formation range, as in the case of the container 2e, it is difficult to satisfy condition C. Therefore, by using the auxiliary tool 3 of the present disclosure instead of the auxiliary tool J2, it is possible to arrange the conductor part 31 in the range R2 from the inner surface 10A of the external electrode 10 to the outer surface 26A of the small diameter part 26. However, from the viewpoint of suppressing abnormal discharge, it is necessary to leave only the dielectric member 4 (first region 321 of the second dielectric part 32) facing the container 2 in the range R2. The converted distance G is not calculated for the conductor portion 31. Therefore, the thickness of the dielectric member 4 and the gap 5 arranged in the range R2 is reduced by the thickness of the conductor portion 31, which reduces the converted distance G and the dielectric loss, thereby sufficiently improving the gas barrier properties of the container 2e. The "thickness" referred to here corresponds to the radial dimension of the container 2 and the external electrode 10.

[0104] From the mathematical theory of the converted distance G described above, the gas barrier properties can be adjusted by adjusting the ratio between the thickness of the conductive portion 31 of the auxiliary tool 3 and the thickness of the second dielectric portion 32. Although it is difficult to adjust the thickness of the external electrode 10, which also serves as a vacuum chamber, or the first dielectric member 12 already provided on the external electrode 10, the overall thickness d all The thickness d of the conductor portion 31 (Fig. 4(a)) c and the thickness d of the second dielectric portion 32 d It is easy to manufacture the assisting tool 3 with different ratios.

[0105] [Effects of this embodiment] As described above, the film-forming auxiliary tool 3 of this embodiment, the film-forming apparatus 1 equipped with the same, and the method for manufacturing a coated container 2c using the auxiliary tool 3 can suppress abnormal discharge while ensuring sufficient gas barrier properties even for containers 2 with special shapes that have traditionally been difficult to provide with sufficient gas barrier properties. It is easy to prepare multiple types of auxiliary devices 3 with different shapes depending on the shape of the container 2, the internal dimensions of the chamber, etc., and there is no need to change the shape of the first dielectric member 12 or the external electrode 10, which requires a lot of cost and work when changing the shape. According to this embodiment, by selecting the shape of the auxiliary device 3, setting the thickness ratio between the conductive portion 31 and the second dielectric portion 32, etc., it is possible to achieve the required level of gas barrier properties for containers 2 of various shapes.

[0106] [Modification] Modifications of the present disclosure will be described below, with the same reference numerals used to designate elements that are similar to elements already described. 15 and 16 includes a second dielectric portion 42 and a plurality of round rods 41 as conductor portions embedded inside the second dielectric portion 42. As shown in Fig. 16, the plurality of round rods 41 are arranged at equal intervals in the circumferential direction of the cylindrical second dielectric portion 42. The round bar 41 is made of, for example, aluminum or an alloy thereof. The second dielectric portion 42 is made of, for example, PTFE. The round bar 41 is inserted into a hole formed in the second dielectric portion 42 by drilling.

[0107] The results of a film formation test performed using the film formation apparatus 1 for this modified example, the above-described embodiment, and a comparative example are shown in the table below. In the embodiment, an auxiliary tool 3 was used, which had a second dielectric part 32 provided by PTFE coating on an aluminum conductor part 31. In the comparative example, as shown in FIG. 14, an auxiliary tool J2 made only of a dielectric was used to form a film on a container 2 similar to the modified example and the embodiment. The shape of the auxiliary tool J2 used here is the same as that of the auxiliary tools 3 and 3-4. The RF (Radio Frequency) output of the high-frequency power supply 17, the film formation time, and the flow rate of the source gas are as shown in Table 2 below. The flow rate unit sccm (Standard Cubic Centimeter per Minute) refers to ccm (cc / min) converted to a value at 1 atmosphere and 0°C.

[0108] [Table 2]

[0109] As can be seen from Table 2 above, the gas barrier properties of the embodiment are more than twice as high as those of the comparative example, reaching the required level. The modified example also improves the gas barrier properties compared to the comparative example.

[0110] As can be seen from the above table, a sufficiently high gas barrier property can be obtained by an embodiment in which the ratio of the thickness of the conductor part 31 to the total thickness of the auxiliary tool 3 is significantly high. Depending on the shape of the container 2, modified versions can be expected to achieve the required level of gas barrier property. Furthermore, an increase in the volume of the conductor part 41 in the auxiliary tool 3-4 can be expected to improve the gas barrier property.

[0111] 17 is a schematic diagram showing a portion of an auxiliary tool 3-5 arranged around the small diameter portion 25 of the container. The auxiliary tool 3-5 includes a second dielectric part 42 made of, for example, PTFE, and a plurality of strip-shaped conductor parts 43 inserted into grooves formed therein. The auxiliary tool 3-5 can be configured by dividing it into a plurality of members. The plurality of conductor parts 43 are aligned in the vertical direction z and are each continuous along the circumferential direction of the small diameter portion 25. The plurality of strip-shaped conductor portions 43 may be exposed at the outer periphery 421 of the second dielectric portion .

[0112] 18 shows an example in which an auxiliary tool 3-8 having a shape corresponding to a recess 241 formed in the bottom 24 is used in addition to an auxiliary tool 3 having a shape corresponding to the neck 22 of a container 2f. The auxiliary tool 3-8 has a frustum-shaped conductive part 31 that follows the shape of the recess 241, and a second dielectric part 32 that serves as a coating that covers the surface of the conductive part 31. The auxiliary member 3-8 can be provided, for example, at the bottom of the first dielectric member 12. The auxiliary member 3-8 improves the quality and thickness of the barrier film formed in the recess 241, thereby improving the gas barrier properties of the container 2f as a whole. The gas barrier properties can be adjusted by adjusting the thicknesses (dimensions in the vertical direction z) of the conductor portion 31 and the second dielectric portion 32.

[0113] 19 is placed in a chamber and supported by a first dielectric member 12-2 of a lower assembly 52 while a film formation process is being performed. Therefore, a film formation apparatus 1-3 does not include a gripping tool 15 for gripping a neck portion 22 of the container 2. An auxiliary tool 3 is supported by the first dielectric member 12-1 or an insulating member 511 of an upper assembly 51. The external electrode 10, the first dielectric member 12, and the shield member 14 of the film forming apparatus 1-3 are each divided into an upper and a lower part, and the dividing surface is opened and closed by a lifting mechanism (not shown). As shown in the figure, with the chamber open, the gripping tool Gr is opened to receive the container 2 in an upright position on the lower first dielectric member 12-2. Next, the gripping tool Gr is retracted from the container 2, and the upper assembly 51 is lowered toward the container 2, forming a chamber space between the upper external electrode 10-1 and the lower external electrode 10-2, and the auxiliary tool 3 is placed around the neck 22.

[0114] In addition to the above, it is possible to select and discard the configurations given in the above embodiments, or to change them to other configurations as appropriate. The film formation auxiliary tool of the present disclosure can be given an appropriate shape depending on the various shapes of the container 2. The region of the container 2 where the auxiliary tool 3 is placed is not limited to the neck portion 22 or its vicinity, and may be, for example, a recess formed in the body portion 23.

[0115] [Note] From the above disclosure, the following configuration can be understood. [1] A film formation auxiliary tool (3) used in a film formation device (1) that forms a film on the inner surface of a container (2) is configured to be insertable into the inside of an external electrode (10) that houses the container (2). The auxiliary tool (3) includes a conductor portion (31) and a dielectric portion (32) that is laminated on the conductor portion (31). When the auxiliary tool (3) is inserted into the inside of the external electrode (10), the dielectric portion (32) faces the outer surface of the container (2), and when the auxiliary tool (3) is inserted into the external electrode (10), the dielectric portion (32) and the conductor portion (31) are arranged in this order from the container (2) side between the container (2) and the external electrode (10).

[0116] [2] The film formation auxiliary tool (3) according to [1], wherein the thickness of the conductive portion (31) in the radial direction of the container (2) is greater than the thickness of the dielectric portion (32) in the radial direction.

[0117] [3] The film formation aid (3) according to [1] or [2], wherein the conductor portion (31) is arranged inside the dielectric portion (32) or is arranged closer to the external electrode (10) than the region (321) on the container (2) side of the dielectric portion (32).

[0118] [4] The film-forming auxiliary tool (3) according to any one of [1] to [3], wherein the dielectric portion (32) corresponds to a coating (32) covering at least the surface of the conductor portion (31) facing the container (2).

[0119] [5] The film formation auxiliary tool (3) according to any one of [1] to [4], wherein the auxiliary tool (3) is divided into a plurality of segments (301 to 304) in the circumferential direction of the container (2).

[0120] [6] The film-forming auxiliary tool (3) according to any one of [1] to [5], wherein the auxiliary tool (3) is arranged around a small diameter portion (22, 25, 26) having a radial dimension smaller than the body portion (23) having the largest radial dimension in the container (2) formed in a bottle shape. [7] The film formation auxiliary tool (3) according to [6], wherein the auxiliary tool (3) is configured to be attachable to a gripping tool (15) that grips a predetermined location on the neck portion (22) of the container (2). [8] The film-forming auxiliary tool (3) according to [6] or [7], wherein the small diameter portion (22, 26) extends in the height direction over at least one-third of the height of the container (2). [9] A film-forming device (1) for forming a film on the inner surface of a container (2) includes an external electrode (10) configured to accommodate the container (2), an internal electrode (11) arranged inside the container (2), and an auxiliary tool (3) described in any one of [1] to [8].

[10] The film forming apparatus (1) according to [9], wherein the film forming apparatus (1) is provided with an existing dielectric portion (12) that is provided in advance inside the external electrode (10), and the dielectric portion (32) of the auxiliary tool (3) faces a part of the outer surface of the container (2) when the auxiliary tool (3) is inserted inside the existing dielectric portion (12), and the existing dielectric portion (12) faces another part of the outer surface of the container (2).

[11] The auxiliary tool (3) is divided into a plurality of segments (301-304) in the circumferential direction of the container (2), and at least one segment of the auxiliary tool (3), a separate segment (302), is attached to a support (19) that supports the internal electrode (11); The film forming apparatus (1) according to [9] or

[10] , wherein the segments (301, 303, 304) of the auxiliary tool (3) excluding the separation segment (302) are assembled to a gripping tool (15) that grips predetermined locations on the neck portion (22) of the container (2), and when the container (2) is housed in the external electrode (10) and the internal electrode (11) is inserted into the container (22), all of the segments (301 to 304) of the auxiliary tool (3) are arranged around the container (2).

[12] The film forming apparatus (1) according to any one of [9] to

[11] , comprising: an alternating electric field source (17) that applies an alternating electric field between the external electrode (10) and the internal electrode; a shielding member (14) that surrounds the external electrode (10) while being insulated from the external electrode (10) and is grounded; an exhaust section (13) that exhausts air from the space in which the container (2) is placed; and a gas introduction section (11) that introduces a gas containing a raw material for a film to be formed on the container (2) into the inside of the container (2).

[13] The film forming apparatus (1) according to any one of [9] to

[12] , further comprising a gripping tool (15) for gripping a predetermined location on the neck (22) of the container (2) formed in a bottle shape, the gripping tool (15) corresponding to a dielectric.

[14] A method for producing a container (2) having a coating on the inner surface of the container (2) includes the steps of: (S03) arranging an auxiliary tool (3) according to any one of [1] to [8] around the container (2); (S02, S03) accommodating the container (2) and the auxiliary tool (3) inside an external electrode (10); (S04) evacuating the space in which the container (2) is placed and introducing a gas containing a raw material for the film to be applied to the container (2); and (S05) applying an electric field between the external electrode (10) and an internal electrode (11) placed inside the container (2), to produce a coated container (2c). [Explanation of symbols]

[0121] 1,1-2,1-3 Film deposition equipment 2,2r,2b container 2r1,2r2,2r3,2r4 Side 2c coated container 3,3r Auxiliary tool (film-forming auxiliary tool) 3A Opposite surface 3B Back 4 Dielectric materials 5 void 10 External electrode 10A inner surface 10x external electrodes 11 Inner electrode (inner electrode, gas inlet) 12 First dielectric member (existing dielectric member) 13 Exhaust section 13A Flow path 14 Shielding material 15 Gripping tool 17 High frequency power supply 18 Vacuum suction device 19 Assembly body (support body) 20 Inner surface 21 Mouth 22 Neck (small diameter part) 23 Torso 24 Bottom 26 Small diameter section 27 Neck 28 Shoulders 26A outer surface 31 Conductor part 31B Back 31C Bottom 32 Second dielectric part (coating) 41 Round bar (conductor part) 42 Second dielectric part 51 Upper assembly 52 Lower assembly 101 Peripheral wall 102 Upper Wall 103 Opening 110 Dielectric 121 Peripheral wall 122 Upper Wall 141 Insulating materials 151 Gripper 152 Support member 161 Connector 162 Matching box 191~195 Insulating materials 301 to 304 segments (including separation segment 302) 321 1st area 322 Second area 323 Third area A axis Gr gripper H Height h Effective height of film formation J1,J2 Auxiliary equipment L length R1 projection area R2 Range S01 Container supply step S02 Container storage step S03 Internal electrode insertion and auxiliary device placement step S04 Exhaust and raw material gas introduction step S05 Electric field application step S06 Atmospheric release step S07 Container discharge step z Vertical direction

Claims

1. An auxiliary tool used in a film forming apparatus that forms a film on the inner surface of a container, the auxiliary tool is configured to be insertable into the inside of the external electrode that accommodates the container, The auxiliary tool is a conductor portion and a dielectric portion laminated on the conductor portion, When the auxiliary tool is inserted into the external electrode, the dielectric portion faces the outer surface of the container, When the auxiliary tool is inserted inside the external electrode, the dielectric portion and the conductor portion are arranged in this order from the container side between the container and the external electrode.

2. a thickness of the conductor portion in a radial direction of the container is greater than a thickness of the dielectric portion in the radial direction; The film formation aid according to claim 1 .

3. the conductor portion is disposed inside the dielectric portion, or is disposed closer to the external electrode than a region of the dielectric portion on the container side; The film formation aid according to claim 1 or 2.

4. The dielectric portion corresponds to a coating covering at least the container-side surface of the conductor portion. The film formation aid according to claim 1 or 2.

5. The auxiliary tool is divided into a plurality of segments in the circumferential direction of the container. The film formation aid according to claim 1 or 2.

6. The auxiliary tool is disposed around a small diameter portion of the container formed in a bottle shape, the small diameter portion having a radial dimension smaller than a body portion having a maximum radial dimension. The film formation aid according to claim 1 or 2.

7. The auxiliary tool is configured to be attachable to a gripping tool that grips a predetermined portion of the neck of the container. The film formation aid according to claim 6.

8. The small diameter portion extends in a height direction over at least one-third of the height of the container. The film formation aid according to claim 6.

9. An apparatus for forming a film on the inner surface of a container, an external electrode configured to accommodate the container; an internal electrode disposed inside the container; A film forming apparatus comprising the auxiliary tool according to claim 1 or 2.

10. a pre-installed dielectric portion provided in advance inside the external electrode; the dielectric portion of the auxiliary tool faces a partial area of ​​the outer surface of the container when the auxiliary tool is inserted inside the existing dielectric part, The pre-installed dielectric portion faces another region of the outer surface of the container. The film forming apparatus according to claim 9 .

11. The assisting tool is divided into a plurality of segments in the circumferential direction of the container, At least one of the segments of the auxiliary tool is a separate segment that is assembled to a support that supports the internal electrode, The segments of the auxiliary tool excluding the separation segment are assembled to a gripping tool that grips a predetermined portion of the neck of the container, when the container is received in the outer electrode and the inner electrode is inserted into the container, all the segments of the assisting tool are disposed around the container; The film forming apparatus according to claim 9 .

12. an alternating electric field source that applies an alternating electric field between the external electrode and the internal electrode; a shielding member that surrounds the external electrode while being insulated from the external electrode and is grounded; an exhaust unit that exhausts air from a space in which the container is placed; A gas inlet portion that introduces a gas containing a raw material of the film to be applied to the container into the inside of the container, The film forming apparatus according to claim 9 .

13. a gripping tool for gripping a predetermined portion of the neck of the container formed in a bottle shape; The gripping tool corresponds to a dielectric material. The film forming apparatus according to claim 9 .

14. 1. A method for manufacturing a container having a coating on an interior surface of the container, comprising: placing the aid according to claim 1 or 2 around the container; housing the container and the assisting tool inside an external electrode; evacuating a space in which the container is placed and introducing a gas containing a material for a film to be applied to the container; applying an electric field between the external electrode and an internal electrode disposed inside the container.

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