JP5032080B2 - Gas barrier plastic container manufacturing apparatus and manufacturing method thereof - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a gas barrier plastic container for forming a thin film having a gas barrier property on the inner wall surface of a plastic container by a plasma CVD (chemical vapor deposition) method. Moreover, it is related with the manufacturing method of the container.

  Plastic containers easily absorb odors and are inferior to bottles and cans in gas barrier properties, so that they are difficult to use for oxygen-sensitive beverages such as beer and sparkling liquor. Therefore, a method and apparatus for coating a hard carbon film (diamond-like carbon (DLC)) or the like has been disclosed in order to solve the problems of sorption and gas barrier properties in plastic containers. For example, by using an external electrode having an internal space substantially similar to the outer shape of the target container and an internal electrode inserted into the container through the mouth of the container and also serving as a source gas introduction pipe, Discloses an apparatus for coating a hard carbon film (see, for example, Patent Document 1 or 2). In such an apparatus, high-frequency power is applied to the external electrode in a state where a carbon source gas such as aliphatic hydrocarbons or aromatic hydrocarbon carbon is supplied as a source gas in the container. At this time, the source gas is turned into plasma between both electrodes, and the ions in the generated plasma are attracted to a high-frequency potential difference (self-bias) generated between the external electrode and the internal electrode, and collide with the inner wall of the container. Is formed.

Japanese Patent No. 2788412 Japanese Patent No. 3072269

  However, the present inventors have found that in such a film forming apparatus, the generation of plasma occurs not only in the external electrode in which the plastic container is accommodated, but also in the exhaust chamber communicating with the external electrode. It has been found that the exhaust path from the vacuum pump to the vacuum pump occurs.

  Such plasma generated outside the external electrode causes deterioration of metal parts in the exhaust chamber, metal parts such as pipes in the exhaust path, and non-metal parts used in pipe joints, and shortens the life of the apparatus.

  Moreover, the plasma generated outside the external electrode causes a foreign material derived from the source gas, for example, a carbon-based foreign material, to adhere to the walls of the exhaust chamber and the exhaust path. It is preferable that this carbonaceous foreign material is removed regularly.

  Furthermore, since the plasma generated outside the external electrode shifts the central portion of the plasma generated at the external electrode to the exhaust chamber side, a thick thin film is formed on the shoulder and mouth of the plastic container in the direction of the container main axis. On the other hand, the film thickness was uneven. Such a container having a non-uniform film thickness with respect to the container main axis direction may not be aesthetically pleasing.

  Further, as long as an external electrode having an internal space substantially similar to the outer shape of the target container is used as in the film forming apparatus disclosed in Patent Document 1 or 2, an external electrode corresponding to the shape of the container is different. Must be attached to the film forming apparatus, which increases the cost of the apparatus. In addition, since it takes time to replace the external electrode, the operating rate of the film forming apparatus decreases.

  Accordingly, an object of the present invention is to prevent the generation of carbon-based foreign matter by suppressing the generation of plasma in the exhaust chamber or the exhaust path thereafter, in the gas barrier plastic container manufacturing apparatus, and In the case of forming a film in containers having different shapes, it is not necessary to exchange external electrodes. And it aims at improving productivity of a gas barrier plastic container by reducing the exchange work of an external electrode accompanying periodic foreign substance removal work and container shape change. At the same time, it aims to prevent shortening of the device life.

  Another object of the present invention is to produce a container having high uniformity of thin film thickness with respect to the main axis direction of the apparatus container in the gas barrier plastic container manufacturing method.

An apparatus for producing a gas barrier plastic container according to the present invention includes an external electrode serving as a vacuum chamber for housing a plastic container, an internal electrode serving as a source gas supply pipe that is detachably disposed inside the plastic container, A vacuum pump for exhausting gas inside the external electrode, a power source connected to the external electrode, an exhaust chamber communicating with the internal space of the external electrode and above the mouth of the plastic container, the external electrode, In an apparatus for manufacturing a gas barrier plastic container, comprising an insulating member that electrically insulates the exhaust chamber, and forming a thin film having gas barrier properties by plasma CVD on the inner wall surface of the plastic container.
A spacer made of a dielectric is disposed in a gap space between the inner wall surface of the external electrode and the outer wall surface of the plastic container; and
The combined capacitance of the capacitance of the plastic container itself and the electrostatic capacity of the internal space and C _1, the inner space of the deposition unit and an internal space and the internal space of the exhaust chamber of the vacuum chamber when the combined capacitance of the outer space of which the plastic container was C _2, C _1> C ₂ relation is established, and,
The power supply supplies low frequency power having a frequency of 400 kHz to 4 MHz to the external electrode.

  In the gas barrier plastic container manufacturing apparatus according to the present invention, the plastic container has a shape in which a mouth is reduced in diameter with respect to the body, and the external electrode is slightly smaller than the body diameter of the plastic container. The spacer has a cylindrical inner space having a large inner diameter, and the spacer is sandwiched between the outer wall surface of the plastic container and the cylindrical inner wall surface of the external electrode. It is preferable that the gaps are arranged in the gap space. A bias voltage can be efficiently applied to plastic containers having substantially the same body diameter and different shoulder or neck shapes without exchanging external electrodes.

  In the gas barrier plastic container manufacturing apparatus according to the present invention, the external electrode has an internal space for accommodating the entire plastic container, or an internal space for accommodating the entire plastic container excluding the mouth. Cases are included. A thin film having a gas barrier property can be formed on the inner wall of the mouth of the plastic container, or can be non-deposited.

The method for producing a gas barrier plastic container according to the present invention includes a step of accommodating a plastic container in an external electrode serving as a vacuum chamber;
Arranging an internal electrode serving as a source gas supply pipe inside the plastic container;
Disposing a spacer made of a dielectric in a gap space sandwiched between the inner wall surface of the external electrode and the outer wall surface of the plastic container;
Evacuating the gas inside the external electrode by operating a vacuum pump; and
Blowing the raw material gas under reduced pressure inside the plastic container;
The combined capacitance of the capacitance of the plastic container itself and the electrostatic capacity of the internal space and C _1, in the internal space of the film forming unit and an internal space and the internal space of the exhaust chamber of the vacuum chamber When the synthetic capacitance of the outer space of the plastic container is C ₂ , low frequency power having a frequency of 400 kHz to 4 MHz is supplied to the external electrode under the condition that C ₁ > C ₂ is satisfied, and the raw material Converting the gas into plasma and forming a thin film having gas barrier properties on the inner wall surface of the plastic container; and
It is characterized by having.

The method for producing a gas barrier plastic container according to the present invention includes a case where a carbon film, a silicon-containing carbon film, or a SiO _x film is formed as the gas barrier thin film.

  In the gas barrier plastic container manufacturing apparatus according to the present invention, it is possible to prevent the generation of carbon-based foreign matter by suppressing the generation of plasma in the exhaust chamber or the exhaust path thereafter. In addition, when forming a film in containers having different shapes, it is not necessary to replace the external electrode. As a result, it is possible to reduce periodic foreign object removal work and external electrode replacement work accompanying container shape change, and it is possible to increase the productivity of the gas barrier plastic container. Furthermore, it is possible to prevent the apparatus life from being shortened.

  In addition, the present invention can produce a container with high productivity and high uniformity of the thickness of the thin film in the main axis direction of the apparatus container in the gas barrier plastic container manufacturing method.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. The present embodiment will be described with reference to FIGS. In addition, the same code | symbol was attached | subjected to the common site | part and components. First, the manufacturing apparatus of the gas barrier plastic container which concerns on this embodiment is demonstrated.

FIG. 1 is a schematic configuration diagram showing a first embodiment of a gas barrier plastic container manufacturing apparatus according to this embodiment. FIG. 1 is a longitudinal sectional view, and this manufacturing apparatus has a rotationally symmetric shape around the main axis of the plastic container 8. Here, the main axis of the container substantially coincides with the main axis of the internal electrode. As shown in FIG. 1, the gas barrier plastic container manufacturing apparatus 100 according to the first embodiment includes an external electrode 3 serving as a vacuum chamber that houses a plastic container 8, and a raw material that is removably disposed inside the plastic container 8. An internal electrode 9 serving as a gas supply pipe, a vacuum pump 23 for exhausting the gas inside the external electrode 3, a power source 27 connected to the external electrode 3, an internal space 30 of the external electrode 3, and an opening of the plastic container 8 And an insulating member 4 that electrically insulates the external electrode 3 and the exhaust chamber 5 from each other, and a thin film having gas barrier properties by plasma CVD on the inner wall surface of the plastic container 8. A device for manufacturing a gas barrier plastic container to be formed, and a spacer made of a dielectric material in a gap space between the inner wall surface of the external electrode 3 and the outer wall surface of the plastic container 8 6 is arranged, and the combined capacitance of the capacitance of the plastic container 8 itself and the electrostatic capacity of the internal space and C _1, the interior space of the exhaust chamber 5 and the interior space 30 of the vacuum chamber 3 when the combined capacitance of the outer space of the plastic container 8 in the internal space of the deposition unit 7 including the 31 was _{C 2,} the relationship of C 1> _{C 2} is satisfied, and, power supply 27 is frequency 400kHz~ A low frequency power of 4 MHz is supplied to the external electrode 3.

  The spacer 36 made of a dielectric is disposed in a gap space sandwiched between the inner wall surface of the external electrode 3 and the outer wall surface of the plastic container 8 in order to prevent abnormal discharge when low frequency power is applied. Preferably, a spacer having a shape that substantially fills the gap space is disposed. The spacer 36 made of a dielectric is preferably formed of an inorganic material such as glass or ceramics or a heat resistant resin. Preferably, polytetrafluoroethylene, tetrafluoroethylene / barfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polyphenylene oxide, polyimide, polyethersulfone, polyetherimide, polyphenylene sulfide Or polyetheretherketone. The spacer 36 made of a dielectric is preferably formed in a ring shape so as to be disposed so as to surround the plastic container 8. The ring shape may be divided into several parts.

  The external electrode 3 is formed in a hollow with a conductive material such as metal to form a vacuum chamber, and has an internal space 30 for accommodating a plastic container 8 to be coated, for example, a PET bottle which is a container made of polyethylene terephthalate resin. The external electrode 3 includes an upper external electrode 2 and a lower external electrode 1. The upper portion of the lower external electrode 1 is detachably attached to the lower portion of the upper external electrode 2 via an O-ring 10. The plastic container 8 can be mounted by detaching the lower external electrode 1 from the upper external electrode 2. The external electrode 3 is sealed from the outside by an O-ring 37 disposed between the insulating member 4 and the external electrode 3 and an O-ring 10 disposed between the upper external electrode 2 and the lower external electrode 1. . In FIG. 1, the external electrode 3 is divided into two parts, that is, the upper external electrode 2 and the lower external electrode 1. However, the external electrode 3 is divided into three or more for the convenience of production, and an O-ring is sealed between them. You may do it.

  The plastic container 8 generally has a shape in which the mouth is reduced in diameter with respect to the body part, but the details are not necessarily unified, and can be appropriately changed depending on the design of the container. Therefore, the shoulder shape, neck shape, or mouth shape of the container differs depending on the contents. In the gas barrier plastic container manufacturing apparatus according to this embodiment, the internal space 30 formed in the external electrode 3 is a cylindrical space, for example, a cylinder so that the plastic container 8 can be accommodated even if the shape and capacity are different. It is preferable that it is a space of a shape or a rectangular tube shape. If the internal space 30 is a cylindrical space, even if the shoulder shape, neck shape, or mouth shape of the container is different, it can be used in common without replacing the external electrode. As a result, the replacement work time of the external electrode and the production cost of the external electrode can be reduced. FIG. 1 shows the case of a cylindrical shape.

  Further, the external electrode 3 preferably has a cylindrical internal space 30 having an inner diameter slightly larger than the body diameter of the plastic container 8. There is no need to dispose a spacer 36 made of a dielectric around the body of the plastic container 8, and self-bias is easily applied. At this time, as shown in FIG. 1, the spacer 36 a made of a dielectric is a gap sandwiched between the outer wall surface of the plastic container 8 whose diameter is reduced from the body portion to the mouth portion and the cylindrical inner wall surface of the external electrode 3. It is preferable to arrange in the space. A bias voltage can be efficiently applied to plastic containers having substantially the same body diameter and different shoulder or neck shapes. Further, as shown in FIG. 1, it is preferable to dispose a spacer 36b made of a dielectric material in a gap space between the outer wall surface of the bottom of the plastic container 8 and the cylindrical inner wall surface of the external electrode 3.

  The spacer 36 made of a dielectric material preferably has a shape that is substantially in contact with the outer wall surface of the plastic container 8. If the container shape is different, the shape of the gap space is different, and each of them should be replaced accordingly. Is preferred.

  In the gas barrier plastic container manufacturing apparatus according to the present embodiment, as shown in FIG. 1, an exhaust chamber 5 is provided which communicates with the internal space 30 of the external electrode 3 and above the mouth of the plastic container 8. It is preferable to arrange an insulating member 4 that electrically insulates the exhaust chamber 5 between the external electrode 3 and the exhaust chamber 5. By providing the exhaust chamber 5, the gas pressure change in the internal space 30 can be reduced when the internal space 30 of the external electrode 3 is exhausted. The exhaust chamber 5 adjusts the gas flow when the source gas blown from the internal electrode 9 flows through the plastic container 8 and is exhausted from the mouth. The insulating member 4 prevents low frequency power from being directly applied to the exhaust chamber 5. Here, to electrically insulate means to insulate DC, and in the case of low frequency power, it becomes capacitive coupling, and very low frequency power flows through the exhaust chamber 5.

  The insulating member 4 is disposed between the external electrode 3 and the exhaust chamber 5, and an opening 32 a is formed at a location corresponding to the position above the mouth of the plastic container 8. The opening 32a allows the external electrode 3 and the exhaust chamber 5 to be in air communication. The insulating member 4 is preferably formed of an inorganic material such as glass or ceramics, or a heat resistant resin. The insulating member 4 is more preferably made of a dielectric material having a small dielectric loss. Preferably, polytetrafluoroethylene, tetrafluoroethylene / barfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polyphenylene oxide, polyimide, polyethersulfone, polyetherimide, polyphenylene sulfide Or polyetheretherketone.

  The exhaust chamber 5 is formed hollow with a conductive material such as metal and has an internal space 31. The exhaust chamber 5 is disposed on the insulating member 4. At this time, the space between the exhaust chamber 5 and the insulating member 4 is sealed by the O-ring 38. Then, in order to make the internal space 31 and the internal space 30 communicate with each other in air, an opening 32b having substantially the same shape is provided in the lower portion of the exhaust chamber 5 corresponding to the opening 32a. The exhaust chamber 5 is connected to a vacuum pump 23 via an exhaust path including a pipe 21, a pressure gauge 20, a vacuum valve 22, and the like, and the internal space 31 is exhausted.

  By disposing the exhaust chamber 5 on the insulating member 4, the lid 6 is formed, the external electrode 3 is sealed, and the film forming unit 7 that can be sealed is assembled. At this time, the film forming unit 7 has two chambers, an internal space 30 of the external electrode 3 and an internal space 31 of the exhaust chamber 5, which are connected through the openings 32a and 32b.

  The plastic container according to the present invention is, for example, a plastic bottle, cup or tray. It includes a container that is used in the open state without using a lid, a stopper, a seal, or a container. The size of the opening is determined according to the contents. The plastic container 8 has a predetermined thickness with moderate rigidity and does not include a soft packaging material formed of a sheet material without rigidity. The filling material of the plastic container according to the present invention is, for example, a beverage such as beer, sparkling liquor, carbonated beverage, fruit juice beverage, or soft drink, a pharmaceutical product, an agrochemical product, or a dry food product that dislikes moisture absorption.

  Resin used when molding the plastic container 8 is, for example, polyethylene terephthalate resin (PET), polyethylene terephthalate-based copolyester resin (copolymer using cyclohexane dimethanol instead of ethylene glycol as the alcohol component of polyester is PETG) Called Eastman Chemical), polybutylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin (PP), cycloolefin copolymer resin (COC, cyclic olefin copolymer), ionomer resin, poly-4-methyl Pentene-1 resin, polymethyl methacrylate resin, polystyrene resin, ethylene-vinyl alcohol copolymer resin, acrylonitrile resin, polyvinyl chloride resin, polyvinyl chloride Styrene resins - down resin, polyamide resin, polyamideimide resin, polyacetal resin, polycarbonate resin, polysulfone resin, ethylene tetrafluoride resin, acrylonitrile - styrene resins or acrylonitrile - butadiene. Among these, PET is particularly preferable.

  The internal electrode 9 also serves as a raw material gas supply pipe, and a gas flow path is provided therein, through which the raw material gas passes. At the tip of the internal electrode 9, a gas outlet 9a, that is, an opening of a gas flow path is provided. One end of the internal electrode 9 is fixed by a wall of the internal space 31 of the exhaust chamber 5, and the internal electrode 9 is disposed in the film forming unit 7. When the plastic container 8 is set in the external electrode 3, the internal electrode 9 is disposed in the external electrode 3 and disposed inside the plastic container 8 from the mouth. That is, the internal electrode 9 is inserted into the internal space 30 of the external electrode 3 through the internal space 31 and the openings 32a and 32b with the upper part of the inner wall of the exhaust chamber 5 as the base end. The tip of the internal electrode 9 is disposed inside the plastic container 8. The internal electrode 9 is preferably grounded.

  The raw material gas supply means 16 introduces the raw material gas supplied from the raw material gas generation source 15 into the plastic container 8. That is, one side of the pipe 11 is connected to the base end of the internal electrode 9, and the other side of the pipe 11 is connected to one side of the mass flow controller 13 via the vacuum valve 12. The other side of the mass flow controller 13 is connected to a source gas generation source 15 via a pipe 14. The source gas generation source 15 generates a hydrocarbon gas source gas such as acetylene.

The thin film having gas barrier properties in the present invention refers to a thin film that suppresses oxygen permeation, such as a carbon film including a DLC (diamond-like carbon) film, a Si-containing carbon film, or a SiO _x film. As the source gas generated from the source gas generation source 15, a volatile gas containing the constituent elements of the thin film is selected. A publicly known volatile raw material gas is used as a raw material gas when forming a thin film having gas barrier properties.

  As the source gas, for example, when a DLC film is formed, aliphatic hydrocarbons, aromatic hydrocarbons, oxygen-containing hydrocarbons, nitrogen-containing hydrocarbons, etc. that are gaseous or liquid at room temperature are used. In particular, benzene, toluene, o-xylene, m-xylene, p-xylene, cyclohexane and the like having 6 or more carbon atoms are desirable. When used for food containers, aliphatic hydrocarbons, especially ethylene hydrocarbons such as ethylene, propylene or butylene, or acetylene hydrocarbons such as acetylene, arylene or 1-butyne from the viewpoint of hygiene Is preferred. These raw materials may be used alone, or may be used as a mixed gas of two or more. Further, these gases may be diluted with a rare gas such as argon or helium. In addition, when a silicon-containing DLC film is formed, a Si-containing hydrocarbon gas is used.

The DLC film referred to in the present invention is a film called i-carbon film or hydrogenated amorphous carbon film (aC: H), and includes a hard carbon film. The DLC film is an amorphous carbon film and also has SP ³ bonds. A hydrocarbon gas such as acetylene gas is used as a source gas for forming the DLC film, and a Si-containing hydrocarbon gas is used as a source gas for forming the Si-containing DLC film. By forming such a DLC film on the inner wall surface of a plastic container, a container that can be used in a one-way and returnable manner as a container for beer, sparkling wine, carbonated beverage, sparkling beverage or the like is obtained.

In addition, when a silicon-containing DLC film is formed, a Si-containing hydrocarbon gas is used. Silicified hydrocarbon gas or silicic acid gas includes silicon tetrachloride, silane (SiH ₄ ), hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, methyltriethoxysilane , Vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane and other organic silane compounds, octamethylcyclotetrasiloxane, 1,1,3 , 3-tetramethyldisiloxane, organic siloxane compounds such as hexamethyldisiloxane (HMDSO) are used. In addition to these materials, aminosilane, silazane and the like are also used.

In the case of forming a SiO _x film (silicon oxide film), for example, a mixed gas of silane and oxygen or a mixed gas of HMDSO and oxygen is used as a source gas.

  The vacuum pump 23 exhausts the gas inside the film forming unit 7. That is, one end of the pipe 21 is connected to the exhaust chamber 5, the other end of the pipe 21 is connected to the vacuum valve 22, and the vacuum valve 22 is connected to the vacuum pump 23 via the pipe. This vacuum pump 23 is further connected to an exhaust duct 24. A pressure gauge 20 is connected to the pipe 21 to detect the pressure in the exhaust path. By operating the vacuum pump 23, the internal gas in the plastic container 8 and the gas in the internal space 30 of the external electrode 3 move to the internal space 31 of the exhaust chamber 5 through the openings 32 a and 32 b, and the gas in the internal space 31. Is sent to a vacuum pump 23 through an exhaust path including a pipe 21.

  The film forming unit 7 is connected to a leak pipe 17. The pipe 17 communicates with a leak source 19 (open to the atmosphere) via a vacuum valve 18.

  The low frequency power supply means 35 supplies the low frequency power to the external electrode 3 to turn the raw material gas inside the plastic container 8 into plasma. The low frequency power supply means 35 includes a power source 27 and an automatic matching unit 26 connected to the power source 27, and the power source 27 is connected to the external electrode 3 through the automatic matching unit 26. The low frequency power generated by the power source 27 is applied to the external electrode 3, and a potential difference is generated between the internal electrode 9 and the external electrode 3, whereby the raw material gas supplied into the plastic container 8 is turned into plasma. The frequency of the power source 27 is preferably 400 kHz to 4 MHz. As described above, low frequency power is applied to the exhaust chamber 5 due to capacitive coupling. However, if the frequency of the power source 27 exceeds 4 MHz, the low frequency power applied to the exhaust chamber 5 increases, so the internal space of the exhaust chamber 5 is increased. Also in 31, plasma is likely to be generated, and it is difficult to generate plasma only in the internal space 30 of the external electrode 3. Accordingly, foreign substances derived from the raw material gas such as carbon-based foreign substances are likely to be deposited in the internal space 31, which necessitates cleaning. On the other hand, if the frequency of the power source 27 is less than 400 kHz, ignition failure tends to occur.

In the manufacturing apparatus of the gas barrier plastic container according to the present embodiment, the combined capacitance of the capacitance of the plastic container 8 itself and the electrostatic capacity of the internal space and C _1, exhaust the internal space 30 of the vacuum chamber 3 when the combined capacitance of the outer space of the plastic container 8 in the internal space of the film-forming unit 7 and an internal space 31 of the chamber 5 and the C _2, it is preferable that the relation of C _1> C ₂ is established. When low frequency power having a frequency of 400 kHz to 4 MHz is applied, it is possible to further suppress the generation of plasma in the exhaust chamber 5 or the exhaust path after that.

Next, the principle by which the generation of plasma in the internal space 31 of the exhaust chamber 5 is suppressed when low frequency power with a frequency of 400 kHz to 4 MHz is supplied to the external electrode 3 will be described. FIG. 2 shows a bipolar discharge circuit corresponding to the gas barrier plastic container manufacturing apparatus of the first embodiment. The AC power supply of the circuit shown in FIG. C ₁ represents the combined capacitance of the capacitance of the plastic container 8 itself and the capacitance of the internal space. C ₁ can be measured by connecting an LCR meter to the plastic container 8 and the internal electrode 9. An LCR meter is a device that can measure inductance (L), capacitance (C), resistance (R), and the like. C ₂ represents the combined capacitance of the outer space of the plastic container 8 in the inner space of the film forming unit 7 including the inner space 30 of the vacuum chamber 3 and the inner space 31 of the exhaust chamber 5. For example, it is the combined capacitance of the capacitance of the gap space sandwiched between the inner wall surface of the vacuum chamber 3 and the outer wall surface of the plastic container 8 and the capacitance of the inner space 31 of the exhaust chamber 5. When the insulating member 4 is arranged, the electrostatic capacity of the internal space corresponding to the opening 32a is applied to C _2. In addition, when the spacers 36 are arranged so as to occupy the gap space, the capacitance of the spacer becomes the capacitance of the gap space. C ₂ can be measured by connecting an LCR meter to the inner wall surface of the external electrode 3 and the inner wall surface of the exhaust chamber 5. Z _p1 represents the impedance of plasma generated in the plastic container 8, and Z _p2 represents the impedance of plasma generated outside the plastic container 8, for example, in the exhaust chamber 5. In the circuit of FIG. 2, each side of Z _p1 and Z _p2 represents a sheath. If the current flowing through the entire circuit I, the current flowing in the _{C 1} side current flowing through the _I 1, _{C 2} side and _{I 2,} the relationship _{I = I} 1 + _{I 2} is satisfied. Here, the impedance A of C ₁ is represented by Equation 1. The impedance B of C ₂ is represented by Equation 2. Here, f is a low frequency.
(Equation ₁ ) Impedance A = 1 / (2πfC ₁ )
(Equation ₂ ) Impedance B = 1 / (2πfC ₂ )

The gas barrier plastic container manufacturing apparatus 100 of FIG. 1 is preferably designed so that the relationship of C ₁ > C ₂ is established. The internal space 30 of the external electrode 3 preferably has a size that can completely or substantially accommodate the plastic container 8, but may be designed by freely changing the capacity if the size is larger than that. In addition, the capacity of the internal space 31 of the exhaust chamber 5 or the material and thickness of the insulating member 4 may be freely changed and designed. A capacity variable means for the internal space 31 or the internal space 30 may be provided. You may provide the change means of the material of the insulating member 4, the change means of thickness, or both. For example, when the device is manufactured so as to increase the capacity of the internal space 30 of the external electrode 3, the thickness of the insulating member 4 is increased in advance so that the relationship of C ₁ > C ₂ is established, or the insulating member 4 The device is manufactured with a material having a small relative dielectric constant, or the device is manufactured so as to increase the capacity of the internal space 31 of the exhaust chamber 5. Consider a case where low frequency power of 400 kHz is output from the power source 27. In the manufacturing apparatus 100 of FIG. 1, by designing so that the relationship of C ₁ > C ₂ , preferably the relationship of C ₁ >> C ₂ is established, the impedance B is expressed as shown in Equation 3 with the impedance A as a reference. It becomes possible to raise relatively. At this time, the generation of plasma in the internal space 30 of the plastic container 8 is left as it is, and only the generation of plasma in the internal space 31 of the exhaust chamber 5 can be suppressed. And it is possible to increase the I ₁ shown in FIG.
( _Equation 3) Impedance B _{(f = 400 kHz)} / Impedance A _{(f = 400 kHz)} = C ₁ / C ₂

On the other hand, Equation 4 is obtained from Equation 1 and Equation 2. According to Equation 4, it can be seen that the difference (impedance B-impedance A) increases as f decreases, only when C ₁ -C ₂ is positive, that is, when the relationship of C ₁ > C ₂ holds. If the relationship of C ₁ >> C ₂ is established, the difference becomes larger.
(Equation 4) impedance B- impedance _{A = 1 / 2πf · {(} C 1 -C 2) / C 1 C 2}

The gas barrier plastic container manufacturing apparatus 100 of FIG. 1 is designed so that a relationship of C ₁ > C ₂ , preferably a relationship of C ₁ >> C ₂ , and a plasma energy source of a source gas having a frequency of 400 kHz to By supplying the low frequency power of 4 MHz, the impedance B is relatively increased with respect to the impedance A, so that the generation of plasma in the exhaust path leading to the exhaust chamber 5 and further to the vacuum pump 23 is suppressed. Can do. As a result, damage due to plasma attack in the exhaust chamber and the exhaust path can be reduced, and the amount of source gas-based foreign matter, for example, carbon-based foreign matter, can be reduced.

  As described above, the plasma generation region can be adjusted by appropriately designing and setting the impedance in the manufacturing apparatus. Furthermore, a magnetic field can be used to adjust a fine generation region or plasma density distribution. A technique for adjusting the plasma density distribution using a magnetic field is known. However, in the apparatus shown in FIG. 1, the internal space of the plastic container 8 from the spacer 36 and / or the external electrode 3 by installing a permanent magnet or an electromagnetic magnet. A magnetic field can be applied in the direction of. Alternatively, in the apparatus shown in FIG. 1, the magnets may be arranged such that the N pole and the S pole are aligned in a direction parallel to the main axis direction of the plastic container. When arranging a plurality of magnets, they are arranged on the circumference centering on the main axis of the plastic container 8, preferably at equal intervals. The permanent magnet is, for example, a Ne—Fe—B magnet.

Here, in order to improve the stability of the plasma ignition of the source gas, it is preferable to provide a pointed head (not shown) in the internal electrode 9. More preferably, it is preferable to provide a pointed head at the gas outlet 9 a of the internal electrode 9. Moreover, you may provide a forced ignition means (not shown). In order to assist the secondary electron emission, a secondary electron emission layer may be formed by coating a part of the surface of the internal electrode 9 with a secondary electron emission material. Secondary electron emission materials include 2A group alkaline earth metal oxides such as BeO, MgO, CaO, SrO, BaO, 4A group metal oxides such as TiO ₂ and ZrO ₂ , and 2B group metal oxides such as ZnO. , Group 3A metal oxides such as Y ₂ O ₃ , Group 3B metal oxides such as Al ₂ O ₃ and Ga ₂ O ₃ , Group 4B metal oxides such as SiO ₂ , PbO ₂ and PbO, AlN 3B group nitrides such as GaN, SiN and other 3B group nitrides, barium oxynitride, fluorides such as LiF, MgF, and CaF, carbides such as SiC, and carbon such as diamond, carbon nanotube, and DLC System materials are used alone or in combination. These compounds may be used. In the MgO system, for example, MgO—Al ₂ O ₃ , MgO—TiO ₂ , MgO—ZrO ₂ , MgO—V ₂ O ₅ , MgO—ZnO, MgO—SiO ₂ , MgO—SiO ₂ —TiO ₂ , MgO—RuO, MgO—MnOx, MgO—Cr ₂ O _{3 and the} like are available. For example, BaTiO ₃ is BaTiO ₃ . Further, a small amount of a rare earth oxide such as NbO, LaO ₂ or SeO ₂ may be added to the material of the secondary electron emission layer. The secondary electron emission layer is formed by a film forming method such as MOCVD, sputtering, thermal spraying, sol-gel method or the like.

  FIG. 3 is a schematic configuration diagram showing a second embodiment of the gas barrier plastic container manufacturing apparatus according to the present embodiment. In the gas barrier plastic container manufacturing apparatus 100 shown in FIG. 1, the external electrode 3 has an internal space 30 that accommodates the entire plastic container 8, but like the gas barrier plastic container manufacturing apparatus 200 shown in FIG. 3. Moreover, you may have the internal space 30 which accommodates the whole except the opening | mouth part of the plastic container 8. FIG. The gas barrier plastic container manufacturing apparatus 100 can uniformly form a thin film having gas barrier properties on the inner wall of the mouth of the plastic container 8. The gas barrier plastic container manufacturing apparatus 200 does not form a thin film having a gas barrier property only on the inner wall of the mouth portion of the plastic container 8, and uniformly forms the remaining inner wall surface except the inner wall of the mouth portion of the plastic container 8. Can be membrane.

  Next, a method for manufacturing a gas barrier plastic container according to this embodiment will be described. Unless otherwise specified, the case where the DLC film is formed as a thin film having gas barrier properties using the gas barrier plastic container manufacturing apparatus 100 of FIG. 1 will be described.

The method for producing a gas barrier plastic container according to the present invention includes a step of housing a plastic container in an external electrode serving as a vacuum chamber, a step of disposing an internal electrode serving as a source gas supply pipe inside the plastic container, and the external A step of disposing a spacer made of a dielectric material in a gap space sandwiched between an inner wall surface of the electrode and an outer wall surface of the plastic container; a step of evacuating a gas inside the external electrode by operating a vacuum pump; a step of blown inside the raw material gas of the plastic container under reduced pressure, the capacitance of the plastic container itself and the combined capacitance of the capacitance of the internal space and C _1, and the internal space of the vacuum chamber when the combined capacitance of the outer space of the plastic container in the internal space of the film forming unit and an internal space of the exhaust chamber and a C _2, C > Under conditions that the relationship C ₂ is established, the supplied low-frequency power having a frequency 400kHz~4MHz the external electrodes, and plasma of the source gas, forming a thin film having a gas barrier property on the inner wall surface of said plastic container Forming a film.

(Plastic container accommodation process, internal electrode placement process and dielectric spacer placement process)
The inside of the film forming unit 7 is opened to the atmosphere by opening the vacuum valve 18, and the lower external electrode 1 of the external electrode 3 is removed from the upper external electrode 2. A spacer 36a made of a dielectric material is previously inserted from the lower side of the upper external electrode 2 and fixed. Next, the plastic container 8 is inserted into the space in the upper external electrode 2 from the lower side of the upper external electrode 2 and installed in the internal space 30 of the external electrode 3. At this time, the internal electrode 9 is inserted into the plastic container 8. A spacer 36b made of a dielectric is fixed to the lower external electrode 1. Next, the lower external electrode 1 is attached to the lower part of the upper external electrode 2, and the external electrode 3 is sealed with an O-ring 10. Through the above operation, the plastic container 8 is accommodated in the internal space 30 of the external electrode 3, the internal electrode 9 is disposed inside the plastic container 8, and the inner wall surface of the external electrode 3 and the outer wall surface of the plastic container 8 are disposed. A spacer 36 made of a dielectric is disposed in the gap space between the two.

(Exhaust process of gas inside the external electrode)
Next, the inside of the plastic container 8 is replaced with a raw material gas and adjusted to a predetermined film forming pressure. That is, as shown in FIG. 1, after the vacuum valve 18 is closed, the vacuum valve 22 is opened, the vacuum pump 23 is operated, and the gas inside the external electrode 3 is electrically connected to the external electrode 3 by the insulating member 4. It exhausts via the insulated exhaust chamber 5. Thereby, the inside of the film forming unit 7 including the inside of the plastic container 8 is exhausted through the pipe 21, and the inside of the film forming unit 7 is evacuated. The pressure in the film forming unit 7 at this time is, for example, 2.6 to 66 Pa.

(Process to blow out raw material gas)
Next, the vacuum valve 12 is opened, a hydrocarbon gas such as acetylene gas is generated in the source gas generation source 15, this hydrocarbon gas is introduced into the pipe 14, and the hydrocarbon gas whose flow rate is controlled by the mass flow controller 13 is supplied. The gas is blown out from the gas outlet 9a through the pipe 11 and the internal electrode (raw material gas supply pipe) 9 having the ground potential. Thereby, the hydrocarbon gas is introduced into the plastic container 8. The inside of the film forming unit 7 and the inside of the plastic container 8 are maintained at a pressure suitable for the film formation of the DLC film (for example, about 6.6 to 665 Pa) by the balance of the controlled gas flow rate and the exhaust capacity, and stabilized. Let

(Deposition process of thin film with gas barrier properties)
Next, low frequency power (for example, 1 MHz) with a frequency of 400 kHz to 4 MHz is supplied to the external electrode 3 when the source gas is blown out into the plastic container 8 under a predetermined reduced pressure. The raw material gas in the plastic container 8 is turned into plasma using the low frequency power as an energy source. As a result, a DLC film is formed on the inner wall surface of the plastic container 8. That is, by supplying low frequency power to the external electrode 3, a bias voltage is generated between the external electrode 3 and the internal electrode 9, and the raw material gas in the plastic container 8 is turned into plasma to generate hydrocarbon plasma. A DLC film is formed on the inner wall surface of the plastic container 8. At this time, the automatic matching unit 26 matches the impedance by the inductance L and the capacitance C so that the reflected wave from the entire electrode supplying the output is minimized. In the gap space between the inner wall surface of the external electrode 3 and the outer wall surface of the plastic container 8, the spacer 36 made of a dielectric is disposed, so that abnormal discharge does not occur.

In the gas barrier plastic container manufacturing apparatus 100 of FIG. 1, low-frequency power with a frequency of 400 kHz to 4 MHz is supplied in a state where the relationship of C ₁ > C ₂ , preferably C ₁ >> C ₂ is established. Thus, as described in FIG. 2 and Equations 1 to 4, it is possible to suppress the generation of plasma in the exhaust path leading to the exhaust chamber 5 and then to the vacuum pump 23. Thereby, the damage by the plasma attack of the exhaust chamber 5 or the exhaust path can be reduced, and the generation amount of the raw material gas-based foreign matters can be reduced. Here, as the generation of plasma in the internal space 31 of the exhaust chamber 5 is suppressed, energy is consumed for the generation of plasma in the internal space 30 of the external electrode 3 and the generation of plasma is increased accordingly. When the center portion to be reached is the portion from the shoulder portion to the mouth portion of the plastic container 8, the center portion moves to the body portion that is the center of the plastic container 8. Therefore, the film thickness distribution along the main axis direction of the container is made uniform.

  By uniforming the film thickness distribution, the film thickness of the DLC film on the inner wall surface of the mouth portion of the plastic container 8 becomes thinner as compared with the conventional case, so the inner wall surface of the mouth portion is colored due to the DLC film. Is reduced, and the design is improved.

  By changing the shape of the spacer 36 made of a dielectric, it is possible to form a film in another plastic container having a different shape without changing the external electrode 3.

  Next, the output of the low frequency power from the power source 27 is stopped, the plasma is extinguished, and the DLC film formation is completed. At almost the same time, the vacuum valve 12 is closed to stop the supply of the raw material gas.

  Next, the vacuum pump 23 exhausts the hydrocarbon gas remaining in the film forming unit 7 and the plastic container 8. Thereafter, the vacuum valve 22 is closed, and the exhaust is finished. The pressure in the film forming unit 7 at this time is 6.6 to 665 Pa. Thereafter, the vacuum valve 18 is opened. Thereby, the film forming unit 7 is opened to the atmosphere.

  In either case, the film formation time is as short as several seconds. The DLC film is formed to have a thickness of 0.003 to 5 μm.

  Hereinafter, the present invention will be described in more detail with reference to examples. The plastic container used in the examples has a capacity of 500 ml, a container height of 207 mm, a container body diameter of 68 mm, a mouth opening inner diameter of 21.74 mm, a mouth opening outer diameter of 24.94 mm, and a mouth height of 21.74 mm. It is a round PET (polyethylene terephthalate) bottle having a thickness of 0 mm, a container barrel thickness of 0.3 mm, and a resin amount of 30 g / piece.

Evaluation was performed as follows.
(Film uniformity)
The film formation uniformity was determined as follows. About 2 cm above (bottom), 8 cm above (body), and 16 cm above (shoulder) from the bottom of the container, the film thickness is measured by selecting three locations in the circumferential direction. The film thickness was measured with a tentacle alpha-step 500 stylus profilometer. They are averaged to determine the average film thickness of the bottom, body and shoulders. From the average film thicknesses of the bottom, the trunk and the shoulder, select the result with the largest average film thickness (average film thickness A) and the result with the smallest average film thickness (average film thickness B). Obtain film formation uniformity (%). The lower the film formation uniformity (%), the higher the uniformity.
(Formula 5) Film formation uniformity (%) = (average film thickness A−average film thickness B) / (average film thickness A + average film thickness B) × 100
Uniformity of film formation 15% or less: (◯) Good film formation in the container height direction.
Uniformity of film formation Over 15% and 30% or less: (Δ) The film is formed uniformly in the container height direction, and there is no problem in quality.
Uniformity of film formation exceeds 30%: (x) It can be seen visually that there is unevenness in the container height direction.

(Deposition rate)
The film thickness per unit time (second) was determined by dividing the average film thickness A of the container by the film formation time.
Deposition rate of 10 nm / second or more: (◯) Production efficiency is high and good.
Deposition rate of less than 10 nm / second: (x) There is a problem because the production efficiency is lowered.

(Light emission amount in exhaust chamber)
In order to investigate the presence and extent of plasma generation in the internal space of the exhaust chamber, one end of the optical fiber (light incident part) is installed in the internal space, and the other end of the optical fiber is connected to a discharge sensor (photo diode, manufactured by Yamatake Corporation). It was connected to a photoelectric sensor, HPX-MA-063), and the light incident on the optical fiber was monitored. The position of the light incident portion of the optical fiber is, for example, a location indicated by “D” in the film forming apparatus of FIG. The presence / absence and extent of plasma generation in the exhaust chamber were evaluated based on the output value (V) of the discharge sensor. The larger the output value, the greater the amount of plasma generated in the exhaust chamber.
Light emission amount of 0.3 V or less: (O) No generation of plasma in the exhaust chamber, and good in continuous operation for a long time.
Light emission amount of more than 0.3 V and 0.5 V or less: (Δ) Plasma is slightly generated in the exhaust chamber, but there is no problem in continuous operation for a long time.
Emission amount exceeding 0.5 V: (x) Plasma is generated in the exhaust chamber, causing problems in continuous operation for a long time.

(Amount of foreign matter generated in the exhaust chamber)
A silicon chip A is attached to the wall surface of the opening 32b (for example, a location indicated as E in FIG. 1), and a silicon chip B is attached to the wall surface near the exhaust port of the exhaust chamber 5 (eg, a location indicated as F in FIG. 1). The film was formed in a container 20 times under the same conditions, then taken out and weighed with an electronic balance (manufactured by Shinko Denshi, high-precision electronic balance AF-R220). The amount of adhering foreign matter was determined from the difference in weight before and after film formation.
Adhering foreign matter amount 0.2 mg or less: (◯) There is almost no foreign matter adhering, and it is good for a long time continuous operation.
Adhering foreign matter amount> 0.2 mg to 0.4 mg or less: (Δ) Foreign matter is attached slightly, but there is no problem in continuous operation for a long time.
Adhering foreign matter amount> 0.4 mg: (x) There is a foreign matter adhering, causing a problem in continuous operation for a long time.

(Oxygen permeability of PET bottle)
The oxygen permeability was measured after one week had elapsed after the start of measurement under the conditions of 22 ° C. × 60% RH using an Oxtran manufactured by Modern Control. In the present invention, the oxygen permeability (oxygen barrier property) is calculated per container. When this is converted per area (m ² ), it may be converted in consideration of the inner surface area of the container. In addition, since there is almost no gas permeation | transmission from a mouth part cover, the area is not taken into consideration.
Oxygen permeability: 0.005 ml / day / container or less: (A) Oxygen barrier property is sufficiently good and oxygen-sensitive beverages can be used.
Oxygen permeability 0.005 ml / day / over 0.010 ml / day / container or less: (◯) No problem even if used in beverages with good oxygen barrier properties and oxygen sensitivity.
Oxygen permeability 0.010 ml / day / over container 0.015 ml / day / container or less: (Δ) Can be used as a simple oxygen barrier container without any problem.
Oxygen permeability 0.015 ml / day / over container: (x) There is a problem as an oxygen barrier container.

(Test 1)
A DLC film was formed on the inner wall surface of the PET bottle using the gas barrier plastic container manufacturing apparatus 100 shown in FIG. The film forming conditions are as follows: acetylene is used as the source gas, the source gas flow rate is 120 sccm, the volume of the internal space 31 of the exhaust chamber 5 is 1.2 liters, the thickness of the insulating member 4 (made of polyetheretherketone) is 10 mm, The output of the power source 27 (3.0 MHz) was 600 W, and the film formation time was 2 seconds. In addition, the external electrode 3 having an inner space 30 having a cylindrical shape was used, and a spacer 36 made of polyetheretherketone was installed in a gap space when a PET bottle was put. The inner diameter of the cylindrical shape of the internal space 30 is such that the outer wall surface of the body portion of the PET bottle and the inner wall surface of the internal space 30 are substantially in contact with each other. The combined capacitance of the internal space 30 of the PET bottle 8 and the external electrodes 3 as shown in FIG. 1 and C _1, the combined capacitance of the internal space 31 of the exhaust chamber 5 and the insulating member 4 and the C ₂ At this time, the relationship of C ₁ > C ₂ was established. Evaluation of the amount of foreign matter generated was performed after film formation 20 times under these conditions. The exhaust chamber 5 emitted a slight amount of light at 0.4V. The generation amount (A) of the foreign matter was 0.3 mg and (B) was 0.3 mg, and it was found that the generation of plasma in the internal space 31 of the exhaust chamber 5 was slight. Abnormal discharge did not occur in the gap space between the inner wall surface of the external electrode 3 and the outer wall surface of the PET bottle 8. The film formation uniformity was 18%, and the film formation rate was 14 nm / second. The film formation conditions and results are shown in Table 1.

(Test 2)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 1 except that the frequency of the low frequency was 1.0 MHz. The results are shown in Table 1.

(Test 3)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 2 except that the raw material gas flow rate was 80 sccm. The results are shown in Table 1.

(Test 4)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 1 except that the frequency of the low frequency was 0.4 MHz. The results are shown in Table 1.

(Test 5)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 1 except that a high-frequency power source (frequency 13.56 MHz) was used instead of the low-frequency power source. The results are shown in Table 1.

(Test 6)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 1 except that the frequency of the low frequency was 0.1 MHz. The results are shown in Table 1.

(Test 7)
A DLC film was formed on the inner wall surface of the PET bottle in the same manner as in Test 2 except that the spacer 36 made of polyetheretherketone was not installed. The results are shown in Table 1.

(Test 8)
Capacity 480 ml, container height 207 mm, container body diameter 68 mm, mouth opening inner diameter 21.74 mm, mouth opening outer diameter 24.94 mm, mouth height 21.0 mm, container body thickness 0. A DLC film is applied to the inner wall surface of the PET bottle in the same manner as in Test 2 except that a PET bottle having a round shape of 3 mm, a resin amount of 30 g / piece, and a narrow neck is used, and a polyether ether ketone spacer 36 is used in accordance with the shape. A film was formed. The results are shown in Table 1.

(Test 9)
The oxygen permeability of uncoated PET bottles was measured. The results are shown in Table 1.

(Test 10)
Instead of the gas barrier plastic container manufacturing apparatus 100 shown in FIG. 1, a film having a relationship of C ₁ <C ₂ was used, and the film formation was performed under the same conditions as in Test 2. The film formation conditions and results are shown in Table 1.

  In Table 1, the overall evaluation is described. The presence / absence of abnormal discharge, the amount of luminescence, the amount of adhered foreign matter, the film forming speed, the film forming uniformity, and the oxygen barrier property were used as judgment materials. Among these, a test including evaluation of at least one or a test in which abnormal discharge occurred was judged as comprehensive evaluation x. Furthermore, in the tests other than the comprehensive judgment ×, any test including an evaluation of Δ was judged as an overall evaluation Δ. A test that obtained an evaluation of ○ or ◎ was judged as an overall evaluation ○. The test judged as comprehensive evaluation Δ or ○ has the characteristics of the evaluation items in a well-balanced manner.

  The PET bottle coated with the thin film having gas barrier properties obtained in Test 1 to Test 4 had oxygen barrier properties and suppressed generation of plasma in the exhaust chamber. Abnormal discharge was suppressed by a polyether ether ketone spacer. Moreover, there was little nonuniformity of film formation in the height direction of the container. Furthermore, in Test 8, it was found that the PET bottles having different shapes can be similarly formed without causing abnormal discharge. Therefore, it was found that the cleaning work time for removing foreign substances and the replacement work time of the external electrode can be reduced, and as a result, the production efficiency of the film forming apparatus can be maintained high.

  On the other hand, in Test 5, since a high-frequency power supply was used, a bottle having a good oxygen barrier property was obtained, but the generation of plasma in the exhaust chamber was remarkable, and it took a cleaning work time for removing foreign matters. This causes a reduction in the production efficiency of the film forming apparatus. Moreover, there was unevenness of film formation in the height direction of the container.

  In Test 6, since the frequency was as low as 0.1 MHz, the generation of plasma in the exhaust chamber was suppressed, but the film formation rate was slow and the oxygen barrier property was low.

  In Test 7, since no spacer was used, plasma was generated as an abnormal discharge in the gap space, and excessive power was consumed in that portion, resulting in a decrease in film formation uniformity. As a result, the oxygen barrier property decreased from 0.006 ml / day / container (Test 2) to 0.008 ml / day / container (Test 7) compared to the case without a spacer (Test 2). Further, carbon-based foreign matter adhered to the inner wall surface of the external electrode, and generation of dust was observed with continuous operation. Periodic cleaning work is required due to the generation of dust.

In Test 10, since the relationship of C ₁ <C ₂ was established, carbon-based foreign matter adhered to the inner wall surface of the exhaust chamber, and generation of dust was observed as continuous operation was performed. Periodic cleaning work is required due to the generation of dust. Moreover, since plasma was generated in the exhaust chamber, the film formation rate was low.

It is a schematic block diagram which shows the 1st form of the manufacturing apparatus of the gas barrier plastic container which concerns on this embodiment. The circuit diagram of the bipolar discharge type corresponding to the manufacturing apparatus of the gas barrier plastic container of the 1st form is shown. It is a schematic block diagram which shows the 2nd form of the manufacturing apparatus of the gas barrier plastic container which concerns on this embodiment.

Explanation of symbols

1 Lower external electrode 2 Upper external electrode 3 External electrode (vacuum chamber)
4 Insulating member 5 Exhaust chamber 6 Lid 7 Film forming unit 8 Plastic container (PET bottle)
9 Internal electrode (Raw gas supply pipe)
9a Gas outlet 10, 37, 38 O-ring 11, 14, 17, 21 Piping
12, 18, 22, vacuum valve 13 mass flow controller 15 source gas generation source 16 source gas supply means 19 leak source 20 pressure gauge 23 vacuum pump 24 exhaust duct 26 automatic matching unit (matching box, M.BOX)
27 Power supply 30 Internal space 31 of external electrode (vacuum chamber) Internal space 32, 32a, 32b of exhaust chamber Opening 35 Low frequency power supply means 36, 36a, 36b Spacer 100 Manufacturing apparatus 200 for gas barrier plastic container of first form Manufacturing apparatus for gas barrier plastic container of second form

Claims (5)

An external electrode serving as a vacuum chamber that accommodates the plastic container, an internal electrode serving as a source gas supply pipe that is detachably disposed inside the plastic container, a vacuum pump that exhausts gas inside the external electrode, A power source connected to the external electrode; an exhaust chamber communicating with the internal space of the external electrode and above the opening of the plastic container; and an insulating member for electrically insulating the external electrode and the exhaust chamber. A gas barrier plastic container manufacturing apparatus for forming a thin film having gas barrier properties by plasma CVD on the inner wall surface of the plastic container,
A spacer made of a dielectric is disposed in a gap space between the inner wall surface of the external electrode and the outer wall surface of the plastic container; and
The combined capacitance of the capacitance of the plastic container itself and the electrostatic capacity of the internal space and C _1, the inner space of the deposition unit and an internal space and the internal space of the exhaust chamber of the vacuum chamber when the combined capacitance of the outer space of which the plastic container was C _2, C _1> C ₂ relation is established, and,
The apparatus for producing a gas barrier plastic container, wherein the power supply supplies low frequency power having a frequency of 400 kHz to 4 MHz to the external electrode. The plastic container has a shape in which the mouth portion has a reduced diameter with respect to the body portion,
The external electrode has a cylindrical internal space having an inner diameter slightly larger than the body diameter of the plastic container,
The spacer is disposed in a gap space sandwiched between an outer wall surface of a portion having a reduced diameter from a body portion to a mouth portion of the plastic container and a cylindrical inner wall surface of the external electrode. 2. The apparatus for producing a gas barrier plastic container according to 1.   The said external electrode has an internal space which accommodates the whole of the said plastic container, or has an internal space which accommodates the whole except the opening part of the said plastic container, The Claim 1 or 2 characterized by the above-mentioned. Gas barrier plastic container manufacturing equipment. Storing a plastic container in an external electrode serving as a vacuum chamber;
Arranging an internal electrode serving as a source gas supply pipe inside the plastic container;
Disposing a spacer made of a dielectric in a gap space sandwiched between the inner wall surface of the external electrode and the outer wall surface of the plastic container;
Evacuating the gas inside the external electrode by operating a vacuum pump; and
Blowing the raw material gas under reduced pressure inside the plastic container;
The combined capacitance of the capacitance of the plastic container itself and the electrostatic capacity of the internal space and C _1, in the internal space of the film forming unit and an internal space and the internal space of the exhaust chamber of the vacuum chamber wherein when the combined capacitance of the space outside the plastic container was _{C 2,} under conditions in which the relationship of C 1> _{C 2} is satisfied, and supplies the low frequency power having a frequency 400kHz~4MHz to the external electrodes, the material Converting the gas into plasma and forming a thin film having gas barrier properties on the inner wall surface of the plastic container; and
A method for producing a gas-barrier plastic container, comprising: The method for producing a gas barrier plastic container according to claim 4, wherein a carbon film, a silicon-containing carbon film, or a SiO _x film is formed as the thin film having gas barrier properties.

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