JP4515280B2 - Apparatus and method for manufacturing a plastic container having a gas barrier thin film formed thereon - Google Patents

Description

  The present invention relates to a low-cost, reliable and high-performance gas barrier plastic container, a manufacturing apparatus thereof, and a manufacturing method thereof.

  Various types of containers such as bottles, cans, and plastic containers are known as sealed containers, for example, beverage containers. In recent years, cans and plastic containers have been widely used from the viewpoint of convenience such as good handling properties. Among these, the plastic container easily absorbs odors and has a gas barrier property inferior to that of cans and cans, so it has been difficult to use it for carbonated beverages such as beer and sparkling liquor.

  Accordingly, a method and apparatus for coating a hard carbon film (such as diamond-like carbon) have been disclosed in order to solve the problems of sorption and gas barrier properties in plastic containers. Among them, for example, using an external electrode that is almost similar to the outer shape of the target container and an internal electrode that is inserted into the container through the mouth of the container and also serves as a source gas introduction pipe, hard carbon is applied to the inner surface of the container. A method of coating a film is disclosed (for example, see Patent Document 1 or 2). In such an apparatus, a high frequency voltage is applied to the external electrode in a state where acetylene gas is supplied as a source gas into the container. At this time, the source gas is turned into plasma by the high-frequency power generated between both electrodes, and the ions in the generated plasma are attracted by the high-frequency potential difference (self-bias) of the external electrode and collide with the inner wall of the container to form a film. Is done.

  Forming a hard carbon film having a high gas barrier property uniformly on the entire inner surface of the container is important for improving the gas barrier property of the container. For this purpose, the potential difference that attracts ions to the inner wall of the container must be uniform in the container. That is, as a factor that enables uniform plasma generation and film formation inside the container, it is an extremely important device configuration to make the inner surface of a room-shaped external electrode made of a metal body similar to the outer surface of the container. ing.

Japanese Patent No. 2788412 Patent No. 3072269

  However, forming the inner surface of the external electrode made of metal to be similar to the outer surface of the container has the following drawbacks. That is, it is necessary to prepare an external electrode for each shape of the container. Therefore, an external electrode must be prepared for each container shape, which is expensive. Further, in the manufacturing process, the external electrode has to be replaced every time the shape of the container changes, and improvement has been demanded in terms of efficiency such as workability, handling properties, and labor.

  Therefore, an object of the present invention is to form a conductive thin film on the plastic container itself, and to make this conductive thin film function as an alternative electrode of the external electrode, so that (1) an electrode having a shape completely similar to the container is used. Realizing film formation conditions equivalent to the case, generating uniform plasma, forming a uniform film, and (2) eliminating the need to prepare external electrodes for each container shape, workability, handling properties, It is to eliminate the factor of efficiency reduction such as labor. It is another object of the present invention to provide a manufacturing apparatus capable of supplying high-frequency power to a conductive thin film of a plastic container on which a conductive thin film is formed, and forming a gas barrier thin film on the plastic container. Furthermore, it aims at providing the plastic container with which the gas barrier thin film obtained by that was formed into a film.

As described above, the present inventors have found that the above problem can be solved by forming a conductive thin film on the plastic container itself and functioning this conductive thin film as an alternative electrode of the external electrode. Completed .

An apparatus for manufacturing a plastic container having a gas barrier thin film formed thereon according to the present invention includes a vacuum chamber that houses a plastic container having a conductive thin film formed on at least one of an inner surface and an outer surface of the container;
A ground electrode disposed inside the plastic container or above the mouth of the plastic container;
An exhaust means for exhausting the interior of the vacuum chamber;
A source gas supply means for supplying a source gas of the gas barrier thin film into the plastic container;
High-frequency supply means for supplying high-frequency power to the conductive thin film;
It is characterized by providing. A gas barrier thin film can be formed on the inner surface of the container.

The plastic container manufacturing apparatus in which the gas barrier thin film according to the present invention is formed contains a plastic container in which a conductive thin film is formed on at least one of the inner surface and the outer surface of the container, and A vacuum chamber in which at least a housing portion surrounding the plastic container is formed of a conductive material;
An exhaust means for exhausting the interior of the vacuum chamber;
A source gas supply means for supplying a source gas of the gas barrier thin film to a space inside the vacuum chamber and outside the plastic container;
High-frequency supply means for supplying high-frequency power to the conductive thin film;
It is characterized by providing. A gas barrier thin film can be formed on the outer surface of the container.

According to the present invention, a method of manufacturing a plastic container having a gas barrier thin film formed thereon includes a step of forming a conductive thin film on at least one of an inner surface and an outer surface of the plastic container, and a space inside the plastic container. Supplying raw material gas; placing a grounded electrode inside the plastic container or above the mouth of the plastic container; supplying high-frequency power to the conductive thin film to convert the raw material gas into plasma A gas barrier thin film is formed on the inner surface of the plastic container in contact with the source gas. In addition, the method for manufacturing a plastic container having a gas barrier thin film formed according to the present invention includes a step of forming a conductive thin film on at least one of the inner surface and the outer surface of the plastic container, and a conductive material. a step of accommodating the plastic container in the housing portion of the grounded vacuum chamber, of the housing portion, and a step of supplying a source gas into the space outside of the plastic container, and supplying high frequency power to the conductive thin film Then, the raw material gas is turned into plasma, and a gas barrier thin film is formed on the outer surface of the plastic container in contact with the raw material gas.

  The method for manufacturing a plastic container having a gas barrier thin film formed thereon according to the present invention includes a case where the gas barrier thin film is formed on the conductive thin film.

  The method for manufacturing a plastic container having a gas barrier thin film formed thereon according to the present invention includes a case where the gas barrier thin film is formed on the back side of the surface on which the conductive thin film is formed.

  According to the present invention, it is possible to realize film forming conditions equivalent to the case where an electrode having a shape completely similar to that of a container is used. Thereby, uniform plasma is generated and a uniform film is formed. In particular, uniform film formation is possible even if there are irregularities on the body and bottom of the container. For example, in a plastic container having a petaloid bottom, it is possible to uniformly form a film on a portion where it has been difficult to apply an external electrode precisely. Moreover, it is not necessary to prepare an external electrode for each container shape, and the cost for the external electrode can be reduced. In addition, it is not necessary to replace the external electrode every time the shape of the container changes in the manufacturing process, so it is excellent in terms of efficiency such as workability, handling properties, labor, etc., and it is possible to increase the production efficiency of this container. became. Further, by limiting the places where the conductive thin film is formed, it is also possible to suppress the film formation at places where it is desired to suppress the formation of the gas barrier thin film, such as around the mouth of the container.

  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 manufacturing apparatus according to 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 embodiment)
FIG. 1 is a schematic configuration diagram showing a first embodiment of a plastic container manufacturing apparatus on which a gas barrier thin film is formed. 1, the vacuum chamber 4 is a schematic cross-sectional view in the vertical direction of the container. The manufacturing apparatus 100 according to the present embodiment is an apparatus that forms a gas barrier film on the inner surface of a plastic container having a conductive thin film formed on its inner surface, that is, on the conductive thin film. The manufacturing apparatus 100 according to the present embodiment includes a vacuum chamber 4 that houses a plastic container 6 having a conductive thin film 8 formed on its inner surface, a ground electrode 5 disposed inside the plastic container 6, and a vacuum chamber 4. An exhaust means 18 for exhausting the inside, a raw material gas supply means 15 for supplying the raw material gas of the gas barrier thin film into the plastic container 6, and a high frequency supply means 12 for supplying high frequency power to the conductive thin film 8.

  The container according to the present invention includes a container that is used with a lid, a stopper, or a seal, or a container that is used without being used. The size of the opening is determined according to the contents. The plastic container includes a plastic container having a predetermined thickness having moderate rigidity and a plastic container formed by a sheet material having no rigidity. Examples of the filling material of the plastic container according to the present invention include carbonated beverages, fruit juice beverages, and soft drinks. Moreover, either a returnable container or a one-way container may be used.

  The resin used when molding the plastic container 6 is polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyethylene naphthalate resin, polyethylene resin, polypropylene resin (PP), cycloolefin copolymer resin (COC, cyclic olefin copolymer) ), Ionomer resin, poly-4-methylpentene-1 resin, polymethyl methacrylate resin, polystyrene resin, ethylene-vinyl alcohol copolymer resin, acrylonitrile resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyamide resin, polyamideimide Resin, polyacetal resin, polycarbonate resin, polysulfone resin, or tetrafluoroethylene resin, acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin Rukoto can. Among these, PET is particularly preferable.

  A conductive thin film 8 is formed on the inner surface of the plastic container 6. Examples of the conductive thin film 8 include a metal thin film, an organic thin film, and an inorganic thin film. Examples of the metal thin film include a thin film containing metal powder such as an aluminum vapor deposited thin film and aluminum powder. Organic thin films include conjugated organic thin films such as polyacetylene. Inorganic thin films include transparent conductive thin films such as ITO (tin-doped indium oxide) and FTO (fluorine-doped tin oxide). The method for forming the conductive thin film 8 is appropriately selected depending on the material, and examples thereof include a low-temperature sol-gel method and vacuum deposition by electron beam irradiation. The kind by a vacuum process or a normal pressure process is not ask | required. Although FIG. 1 shows the case where the conductive thin film 8 is formed on the entire inner surface of the plastic container 6, the conductive thin film 8 is placed at a location where gas barrier thin film formation is to be suppressed, for example, near the mouth of the container. It is not necessary to form a film. Since the gas barrier thin film is formed corresponding to the film forming portion of the conductive thin film 8, the position of the gas barrier thin film can be controlled depending on whether the conductive thin film 8 is formed. The film thickness of the conductive thin film 8 is, for example, 0.5 to 50 μm.

  As shown in FIG. 1, the vacuum chamber 4 includes a housing part 1 that is housed so as to surround the container, an insulating member 2 that is disposed on the housing part 1 so as to be airtight, and an insulating member 2. It is comprised from the cover part 3 arrange | positioned so that it may have airtightness. By making the housing part 1 and the insulating member 2 separate, the plastic container 6 can be housed in the vacuum chamber 4. Each boundary of the accommodating part 1, the insulating member 2, and the cover part 3 is sealed with an O-ring interposed. The configuration of the vacuum chamber 4 is not limited to this configuration.

  The accommodating portion 1 is formed from a pressure-resistant material such as metal or plastic. It does not matter whether or not there is conductivity. The shape inside the accommodating part 1 is not particularly limited. In order to accommodate containers of various shapes, it is preferable to have a size that can accommodate a container of the maximum shape that is to be accommodated.

  A space 7 is provided in the insulating member 2 and the lid 3. The lid 3 is made of a conductive material such as metal, and supports a hollow (tubular) ground electrode 5 that also serves as a source gas introduction pipe. The ground electrode 5 is detachably disposed from the mouth of the plastic container 6 to the inside of the container through the space 7 and the opening 27 provided in the insulating member 2. The tip of the ground electrode 5 is a raw material gas outlet 5a. When a source gas introduction pipe is separately provided, the ground electrode 5 may be disposed above the mouth of the plastic container 6 as long as the source gas can be turned into plasma.

  The other end side of the ground electrode 5 is connected to a conduit 13 communicating with the inside of the ground electrode 5. The raw material gas fed into the ground electrode 5 through the conduit 13 is discharged into the plastic container 6 through the blowout port 5a. Thereby, the source gas comes into contact with the inner surface of the plastic container 6. The conduit 13 is made of metal and has conductivity. As shown in FIG. 1, the ground electrode 5 is connected to the ground potential using the pipe line 13.

  In addition, you may provide a container holding means (not shown) for the purpose of taking in and out of a container and the support of a container.

  The raw material gas supply means 15 introduces the raw material gas supplied from the raw material gas generation source 14 into the plastic container 6. That is, the source gas generation source 14 is connected to the other end side of the pipe line 13. A mass flow controller (not shown) is connected to the source gas generation source 14.

The gas barrier thin film in the present invention refers to a thin film that suppresses oxygen permeability, such as a DLC (diamond-like carbon) film, a Si-containing DLC film, a SiO _x film, and an AlN film. As the source gas generated from the source gas generation source 14, a volatile gas containing the constituent elements of the thin film is selected. A publicly known volatile source gas can be used as a source gas when forming the gas barrier thin film. The film thickness of the gas barrier thin film is preferably 5 to 80 nm, for example.

  For example, when a DLC film is formed, gas or liquid aliphatic hydrocarbons, aromatic hydrocarbons, oxygen-containing hydrocarbons, nitrogen-containing hydrocarbons and the like are used as the source gas at room temperature. In particular, benzene, toluene, o-xylene, m-xylene, p-xylene, cyclohexane and the like having 6 or more carbon atoms are desirable. Examples of the aliphatic hydrocarbons include ethylene hydrocarbons or acetylene hydrocarbons. 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 Si-containing DLC film is formed, a Si-containing hydrocarbon gas is used.

The DLC film in the present invention refers to a carbon film called an i-carbon film or a hydrogenated amorphous carbon film (a-CH), which is an amorphous carbon film containing sp ³ bonds. The DLC film has a film quality from hard to soft (polymer-like), and the hydrogen content ranges from 0 atom% to about 70 atom%.

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.

  The exhaust means 18 is formed by a vacuum valve 16, an exhaust pump 17, and piping connecting them. The space 7 is connected to one side of the exhaust pipe. The other side of the exhaust pipe is connected to an exhaust pump 17 via a vacuum valve 16. The exhaust pump 17 is connected to an exhaust duct (not shown). By operating the exhaust means 18, the inside of the vacuum chamber 4 including the space 7 and the internal space of the plastic container 6 is decompressed. The evacuation unit 18 may be configured to evacuate the vacuum chamber 4 to reduce the space outside the container.

  In the vacuum chamber 4, a terminal 9 for supplying high frequency power to the conductive thin film 8 formed in the plastic container 6 is disposed. In FIG. 1, the terminal 9 is disposed on the insulating member 2. One end of the terminal 9 is in contact with the conductive thin film 8 formed on the inner surface of the container through the opening 27 and the mouth of the plastic container 6. The other end side of the terminal 9 is connected to the high frequency supply means 12. A plurality of terminals 9 may be provided.

  The high frequency supply means 12 includes a matching box 10 and a high frequency power supply 11 that supplies a high frequency to the matching box 10. A matching box 10 is connected to the output side of the high frequency power supply 11. The other end side of the terminal 9 is connected to the output side of the matching box 10. The high frequency power supply 11 is grounded. The high frequency power supply 11 generates a high frequency voltage between the ground potential and the high frequency voltage is applied between the conductive thin film 8 and the ground electrode 5. As a result, the raw material gas is turned into plasma in the plastic container 6. The frequency of the high-frequency power source is 100 kHz to 1000 MHz, and for example, an industrial frequency of 13.56 MHz is used. The conductive thin film 8 has the same shape as the container. As a result, it is possible to realize film forming conditions equivalent to the case where an electrode having a shape completely similar to that of the container is used. As a result, more uniform plasma is generated and a uniform film is formed. In particular, uniform film formation is possible even if there are irregularities on the body and bottom of the container. For example, even a plastic container having a petaloid bottom can form a uniform film.

  In this embodiment, a gas barrier thin film such as a DLC film is cited as a thin film to be formed by the manufacturing apparatus. However, the above film forming apparatus can be used when forming another thin film.

(Second Embodiment)
FIG. 2 is a schematic configuration diagram showing a second embodiment of a plastic container manufacturing apparatus in which a gas barrier thin film is formed. 2, the vacuum chamber 4 is a schematic cross-sectional view in the vertical direction of the container. The manufacturing apparatus 200 according to the present embodiment is an apparatus for forming a gas barrier thin film on the inner surface of a plastic container having a conductive thin film formed on the outer surface, that is, on the back side of the surface on which the conductive thin film 8 is formed. It is. Compared with the manufacturing apparatus 100 of the first embodiment, the terminal 9 is arranged on the outer surface side of the plastic container 6 in order to supply high-frequency power to the conductive thin film 8 formed on the outer surface of the plastic container 6. Yes. Although the conductive part between the conductive thin film 8 and the terminal 9 is the body part of the container, it may be a bottom part, a shoulder part, a neck part or a mouth part. A plurality of terminals 9 may be provided. Also in the second embodiment, it is possible to realize film forming conditions equivalent to the case where an electrode having a shape that is completely similar to the container is used.

(Third embodiment)
FIG. 3 is a schematic configuration diagram showing a third embodiment of a plastic container manufacturing apparatus on which a gas barrier thin film is formed. In FIG. 3, the vacuum chamber 4 is a schematic sectional view in the vertical direction of the container. The manufacturing apparatus 300 according to the present embodiment is an apparatus for forming a gas barrier thin film on the outer surface of a plastic container having a conductive thin film formed on the inner surface, that is, on the back side of the surface on which the conductive thin film 8 is formed. It is. The manufacturing apparatus 300 according to the present embodiment accommodates a plastic container 6 in which a conductive thin film 8 is formed on the inner surface of the container, and at least the accommodating portion 1 surrounding the plastic container 6 is formed of a conductive material. A vacuum chamber 4, an exhaust means 18 for exhausting the inside of the vacuum chamber 4, a source gas supply means 15 for supplying the source gas of the gas barrier thin film to the space inside the vacuum chamber 4 and outside the plastic container 6, and conductive High-frequency supply means 12 for supplying high-frequency power to the conductive thin film 8. Differences from the manufacturing apparatus 100 of the first embodiment will be described.

  In the manufacturing apparatus 300 according to the present embodiment, the raw material gas supply means 15 is connected to the storage unit 1. Then, the source gas is blown out from the outlet 20 a of the source gas introduction pipe 20 through the source gas introduction pipe 20 into the space inside the housing portion 1 and outside the plastic container 6. Thereby, the source gas comes into contact with the outer surface of the plastic container 6. The reacted source gas flows into the space 7 through the gas flow path 21 that is provided in the insulating member 2 and communicates with the internal space of the accommodating portion 1 and the space 7, and is discharged from the vacuum chamber 4 by the exhaust means 18. Is exhausted. Moreover, the accommodating part 1 is formed with electroconductive materials, such as a metal, and is electrically connected with the pipe line 13 similarly formed with the metal material. When the pipe line 13 is grounded, the accommodating portion 1 is grounded. The high frequency supply means 12 is the same as that of the first embodiment. With this configuration, a high-frequency voltage is applied between the conductive thin film 8 and the grounded container 1. Then, the source gas is turned into plasma on the outer surface side of the plastic container 6.

(Fourth embodiment)
FIG. 4 is a schematic configuration diagram showing a fourth embodiment of a plastic container manufacturing apparatus on which a gas barrier thin film is formed. In FIG. 4, the vacuum chamber 4 is a schematic sectional view in the vertical direction of the container. The manufacturing apparatus 400 according to the present embodiment is an apparatus that forms a gas barrier thin film on the outer surface of a plastic container having a conductive thin film formed on the outer surface, that is, on the conductive thin film 8. The manufacturing apparatus 400 according to the present embodiment accommodates a plastic container 6 in which a conductive thin film 8 is formed on the outer surface of the container, and at least the accommodating portion 1 surrounding the plastic container 6 is formed of a conductive material. A vacuum chamber 4, an exhaust means 18 for exhausting the inside of the vacuum chamber 4, a source gas supply means 15 for supplying the source gas of the gas barrier thin film to the space inside the vacuum chamber 4 and outside the plastic container 6, and conductive High-frequency supply means 12 for supplying high-frequency power to the conductive thin film 8.

  In the manufacturing apparatus 400 according to the present embodiment, the raw material gas supply means 15 is the same as the manufacturing apparatus 300. Similarly to the manufacturing apparatus 300, the gas flow path 21 is provided in the insulating member 2, and the raw material gas discharged from the outlet 20 a becomes a used raw material gas and then flows into the space 7 and is exhausted by the exhaust means 18. The vacuum chamber 4 is exhausted outside the system. Moreover, the accommodating part 1 is formed with electroconductive materials, such as a metal, and is electrically connected with the pipe line 13 similarly formed with the metal material. When the pipe line 13 is grounded, the accommodating portion 1 is grounded. A terminal 9 is disposed on the outer surface side of the plastic container 6 in order to supply high-frequency power to the conductive thin film 8 formed on the outer surface of the plastic container 6. Although the conductive part between the conductive thin film 8 and the terminal 9 is the body part of the container, it may be a bottom part, a shoulder part, a neck part or a mouth part. A plurality of terminals 9 may be provided. The other end side of the terminal 9 is connected to the high frequency supply means 12. Here, the accommodating part 1 and the terminal 9 are insulated by the insulating member (not shown), and the short circuit is prevented. With this configuration, a high-frequency voltage is applied between the conductive thin film 8 and the grounded container 1. Then, the source gas is turned into plasma on the outer surface side of the plastic container 6.

  In the manufacturing apparatus according to the third and fourth embodiments, a gas barrier thin film is formed on the outer surface of the container. Conventionally, it has been difficult to dispose an electrode having a similar shape in the container so as to be detachable. However, it is possible to realize film forming conditions equivalent to the case where an electrode having a shape completely similar to the container is used. As a result, similar to the case of forming a gas barrier thin film on the inner surface of the container, uniform plasma is generated and a uniform film is formed. In particular, uniform film formation is possible even if there are irregularities on the body and bottom of the container. For example, even a plastic container having a petaloid bottom can form a uniform film.

(Manufacturing method in the manufacturing apparatus of the first embodiment or the second embodiment)
The manufacturing method in the manufacturing apparatus of the first embodiment or the second embodiment is the second method in which the manufacturing apparatus of the first embodiment supplies high frequency power to the conductive thin film formed on the inner surface of the container. The manufacturing process is the same because the manufacturing apparatus of the embodiment has only a difference in supplying high-frequency power to the conductive thin film formed on the outer surface of the container. The film-forming surface of the gas barrier thin film is the inner surface of the container. In the manufacturing apparatus of the first embodiment, a gas barrier thin film is formed on the conductive thin film. In the manufacturing apparatus of the second embodiment, the gas barrier thin film is formed on the back side of the surface on which the conductive thin film is formed. Form a film. A procedure for forming a DLC film on the inner surface of the plastic container 6 using the manufacturing apparatus 200 of the second embodiment will be described with reference to FIG. The plastic container 6 is a round 500 ml PET bottle. The wall thickness of the container wall is about 0.3 mm.

(Preparation of container)
First, an aluminum thin film is formed on the entire surface of the plastic container as a conductive thin film using a vacuum evaporation method. The film thickness of the aluminum thin film was about 2 μm.

(Attaching containers to manufacturing equipment)
Next, a vent (not shown) is opened to open the vacuum chamber 4 to the atmosphere. Next, the accommodating portion 1 and the insulating member 2 are separated, and the plastic container 6 is accommodated in the vacuum chamber 4. The plastic container 6 is housed in a sealed vacuum chamber 4 formed by the housing portion 1, the insulating member 2, and the lid portion 3. At this time, a ground electrode 5 also serving as a source gas introduction pipe provided in the vacuum chamber 4 is inserted into the plastic container 6 through the opening of the plastic container 6.

(Decompression operation)
Next, after closing the vent, the exhaust means 18 is operated to exhaust the air in the vacuum chamber 4 through the exhaust port provided in the lid 3. Then, the vacuum chamber 4 is depressurized until it reaches a required degree of vacuum, for example, 4 Pa. This is because if the degree of vacuum exceeding 4 Pa is sufficient, the container has too many impurities.

(Introduction of raw material gas)
Thereafter, the source gas (for example, acetylene gas) sent from the source gas supply means 15 with the flow rate controlled is introduced into the plastic container 6 from the outlet 5 a of the ground electrode 5. The supply amount of the raw material gas is preferably 20 to 50 ml / min. The concentration of the source gas becomes constant, and is stabilized at a predetermined film formation pressure, for example, 7 to 22 Pa, by controlling the balance between the gas flow rate and the exhaust capacity.

(Plasma deposition)
By operating the high-frequency power source 11, a high-frequency voltage is applied between the ground electrode 5 and the conductive thin film 8 formed on the outer surface of the container via the matching box 10, and the raw material gas plasma is generated in the plastic container 6. Occurs. At this time, the matching box 10 is matched with the impedance of the ground electrode 5 and the conductive thin film 8 by the inductance L and the capacitance C. As a result, a DLC film is formed on the inner surface of the plastic container 6. The output (for example, 13.56 MHz) of the high frequency power supply 11 is approximately 1000 to 2000 W.

  That is, the DLC film is formed on the inner surface of the plastic container 6 by a plasma CVD method. That is, a self-bias is applied to the wall surface of the container by the application of high-frequency power, and plasma source gas ions are accelerated according to the potential difference due to the self-bias and sputtered on the inner surface of the container to form a DLC film. A dense DLC film is formed on the inner surface of the plastic container 6 through the CVD film forming process. The film formation time is as short as several seconds.

(Finish film formation)
The RF output from the high frequency power supply 11 is stopped, and the supply of the raw material gas is stopped. Thereafter, the acetylene gas in the vacuum chamber 4 is exhausted by the exhaust pump 17. Thereafter, the vacuum valve 16 is closed and the exhaust pump 17 is stopped. Thereafter, a vent (not shown) is opened to open the vacuum chamber 4 to the atmosphere, and the above-described film forming method is repeated, whereby a DLC film is formed on the next prepared plastic container. The DLC film is formed to have a thickness of 5 to 80 nm.

  The plastic container produced in this manner was evaluated for oxygen permeability by the same method as the carbon film coated plastic container described in JP-A-8-53117, and had the same oxygen permeability. As a plastic container, capacity 500ml, container height 200mm, container body diameter 71.5mm, mouth opening inner diameter 21.74mm, mouth opening outer diameter 24.94mm, container body thickness 0.3mm, resin When a DLC film was formed to a thickness of 30 nm (average of the entire container) using a container having an amount of 32 g / bottle, the oxygen permeability was 0.0038 ml / container (500 ml PET container) / day) (23 ° C. RH 90%, nitrogen gas Measured value after 20 hours from the start of substitution). In this embodiment, a PET bottle for beverages is used as a container for forming a thin film inside, but a container used for other purposes can also be used.

  A DLC film could be formed on a square 500 ml PET bottle by the same method. When a DLC film was formed to a thickness of 30 nm (average for the entire container), the oxygen permeability was 0.0042 ml / container (500 ml PET container) / day).

(Manufacturing method in the manufacturing apparatus of 3rd Embodiment or 4th Embodiment)
The manufacturing method in the manufacturing apparatus of the third embodiment or the fourth embodiment is the fourth method in which the manufacturing apparatus of the third embodiment supplies high frequency power to the conductive thin film formed on the inner surface of the container. The manufacturing process is the same because the manufacturing apparatus of the embodiment has only a difference in supplying high-frequency power to the conductive thin film formed on the outer surface of the container. The film-forming surface of the gas barrier thin film is the outer surface of the container. In the manufacturing apparatus of the third embodiment, a gas barrier thin film is formed on the conductive thin film. In the manufacturing apparatus of the fourth embodiment, the gas barrier thin film is formed on the back side of the surface on which the conductive thin film is formed. Form a film. A procedure for forming a DLC film on the outer surface of the plastic container 6 using the manufacturing apparatus 400 according to the fourth embodiment will be described with reference to FIG. The plastic container 6 is a round 500 ml PET bottle. The wall thickness of the container wall is about 0.3 mm.

(Preparation of container)
The process of preparing the container on which the conductive thin film is formed is the same as that for manufacturing using the manufacturing apparatus of the second embodiment.

(Attaching containers to manufacturing equipment)
A vent (not shown) is opened to open the vacuum chamber 4 to the atmosphere. Next, the accommodating portion 1 and the insulating member 2 are separated, and the plastic container 6 is accommodated in the vacuum chamber 4. The plastic container 6 is housed in a sealed vacuum chamber 4 formed by the housing portion 1, the insulating member 2, and the lid portion 3. The source gas introduction pipe 20 is disposed on the outside of the container.

(Decompression operation)
The process of pressure reduction operation is the same as that of manufacturing using the manufacturing apparatus of 2nd Embodiment.

(Introduction of raw material gas)
Thereafter, the source gas (for example, acetylene gas) sent from the source gas supply means 15 with the flow rate controlled is introduced into the space outside the plastic container 6 from the outlet 20 a of the source gas introduction pipe 20. The supply amount of the raw material gas is preferably 20 to 50 ml / min. The concentration of the source gas becomes constant, and is stabilized at a predetermined film formation pressure, for example, 7 to 22 Pa, by controlling the balance between the gas flow rate and the exhaust capacity.

(Plasma deposition)
By operating the high frequency power supply 11, a high frequency voltage is applied between the container 1 and the conductive thin film 8 formed on the outer surface of the container via the matching box 10, and the raw material is placed in the outer space of the plastic container 6. Gas plasma is generated. At this time, the matching box 10 is matched with the impedance of the housing portion 1 and the conductive thin film 8 by the inductance L and the capacitance C. Thereby, a DLC film is formed on the outer surface of the plastic container 6. The output (for example, 13.56 MHz) of the high frequency power supply 11 is approximately 1000 to 2000 W.

  That is, the DLC film is formed on the outer surface of the plastic container 6 by a plasma CVD method. That is, self-bias is applied to the vessel wall surface by applying high-frequency power, and the plasma-generated source gas ions are accelerated according to the potential difference due to the self-bias and sputtered on the outer surface of the vessel to form a DLC film. A dense DLC film is formed on the outer surface of the plastic container 6 through the CVD film forming process. The film formation time is as short as several seconds.

(Finish film formation)
The process for ending the film formation is the same as in the case of manufacturing using the manufacturing apparatus of the second embodiment. The DLC film is formed to have a thickness of 5 to 80 nm.

  The plastic container manufactured in this manner was evaluated in the same manner as the container manufactured using the manufacturing apparatus of the second embodiment. As a result, when the DLC film was formed to a thickness of 30 nm (average for the entire container), the oxygen permeability was 0. 0038 ml / container (500 ml PET container) / day) (23 ° C. RH 90%, measured value 20 hours after the start of nitrogen gas replacement).

  A DLC film could be formed on a square 500 ml PET bottle by the same method. When a DLC film was formed to a thickness of 30 nm (average for the entire container), the oxygen permeability was 0.0042 ml / container (500 ml PET container) / day).

  In addition, in the plastic container in which the gas barrier thin film according to the present embodiment is formed, the raw material gas is converted into plasma by another manufacturing apparatus so that the relationship between the electrode to be grounded and the electrode for supplying the high frequency is reversed. A container manufactured in this way.

A plastic container in which the following gas barrier thin film is formed can be obtained by the manufacturing apparatus according to the first to fourth embodiments. That is,
(1) A plastic container in which a conductive thin film is formed on the inner surface of the container, and a gas barrier thin film is formed on the conductive thin film. In the case of this container, the conductive thin film can be an adhesion enhancing layer of the gas barrier thin film.
(2) A plastic container in which a conductive thin film is formed on the inner surface of the container and a gas barrier thin film is formed on the outer surface of the container.
(3) A plastic container in which a conductive thin film is formed on the outer surface of the container and a gas barrier thin film is formed on the conductive thin film. In the case of this container, the conductive thin film can be an adhesion enhancing layer of the gas barrier thin film.
(4) A plastic container in which a conductive thin film is formed on the outer surface of the container and a gas barrier thin film is formed on the inner surface of the container.

  The plastic container according to (2) and (4) may be a plastic container in which only the gas barrier thin film is formed by providing a process for removing the conductive thin film in a subsequent process after forming the gas barrier thin film. In the plastic containers according to (1) to (4), the gas barrier thin film is formed on only one side, but the gas barrier thin film may be formed on both sides.

  In any container of (1) to (4), the conductive thin film becomes an electrode when the gas barrier thin film is formed by the plasma CVD method. And by adjusting the material and film thickness of the conductive thin film, the color tone of the bottle can be changed and the decorativeness can be improved. For example, the film may be formed in a striped pattern so as not to lose its role as an electrode. Further, if the conductive thin film is made of a high gas barrier material, for example, a polyamide-based resin having oxygen absorbability, a plastic container having a higher gas barrier property can be obtained. Further, when the conductive thin film is made of a material having a strong catalytic activity, a container provided with the catalytic function can be provided.

Here, the gas barrier thin film is preferably a DLC film, a SiO _x film, or a Si-containing carbon film.

It is a schematic block diagram which shows 1st Embodiment of the manufacturing apparatus of the plastic container in which the gas barrier thin film was formed into a film. It is a schematic block diagram which shows 2nd Embodiment of the manufacturing apparatus of the plastic container in which the gas barrier thin film was formed into a film. It is a schematic block diagram which shows 3rd Embodiment of the manufacturing apparatus of the plastic container in which the gas barrier thin film was formed into a film. It is a schematic block diagram which shows 4th Embodiment of the manufacturing apparatus of the plastic container in which the gas barrier thin film was formed into a film.

1, receiving portion 2, insulating member 3, lid portion 4, vacuum chamber 5, ground electrode 5a, outlet 6, plastic container 7, space 8, conductive thin film 9, terminal 10, matching box 11, high frequency power supply 12, high frequency Supply means 13, pipe 14, source gas generation source 15, source gas supply means 16, vacuum valve 17, exhaust pump 18, exhaust means 20, source gas introduction pipe 20 a, outlet 21, gas flow paths 100, 200, 300 400 manufacturing equipment

Claims (6)

A vacuum chamber containing a plastic container having a conductive thin film formed on at least one of the inner surface and the outer surface of the container;
A ground electrode disposed inside the plastic container or above the mouth of the plastic container;
An exhaust means for exhausting the interior of the vacuum chamber;
A source gas supply means for supplying a source gas of the gas barrier thin film into the plastic container;
High-frequency supply means for supplying high-frequency power to the conductive thin film;
An apparatus for manufacturing a plastic container having a gas barrier thin film formed thereon. A vacuum chamber that houses a plastic container having a conductive thin film formed on at least one of the inner surface and the outer surface of the container, and at least a housing portion that surrounds the plastic container is formed of a conductive material;
An exhaust means for exhausting the interior of the vacuum chamber;
A source gas supply means for supplying a source gas of the gas barrier thin film to a space inside the vacuum chamber and outside the plastic container;
High-frequency supply means for supplying high-frequency power to the conductive thin film;
An apparatus for manufacturing a plastic container having a gas barrier thin film formed thereon. Forming a conductive thin film on at least one of the inner surface and the outer surface of the plastic container;
Supplying raw material gas to the space inside the plastic container;
Placing a grounded electrode inside the plastic container or above the mouth of the plastic container;
A gas barrier thin film characterized in that high-frequency power is supplied to the conductive thin film , the raw material gas is turned into plasma, and a gas barrier thin film is formed on the inner surface of the plastic container in contact with the raw material gas. A method for producing a plastic container formed into a film. Forming a conductive thin film on at least one of the inner surface and the outer surface of the plastic container;
A step of accommodating the plastic container in an accommodating portion of a vacuum chamber formed of a conductive material and grounded;
A step of supplying a raw material gas to a space outside the plastic container in the housing portion ;
A gas barrier thin film characterized in that a high-frequency power is supplied to the conductive thin film , the raw material gas is turned into plasma, and a gas barrier thin film is formed on the outer surface of the plastic container in contact with the raw material gas. A method for producing a plastic container formed into a film. 5. The method for producing a plastic container having a gas barrier thin film formed thereon according to claim 3 , wherein the gas barrier thin film is formed on the conductive thin film. 5. The method of manufacturing a plastic container having a gas barrier thin film formed thereon according to claim 3 , wherein the gas barrier thin film is formed on a back side of the surface on which the conductive thin film is formed.

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