JP3868403B2 - Apparatus for forming barrier film on inner surface of plastic container and manufacturing method of inner surface barrier film-coated plastic container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for forming a barrier film on the inner surface of a plastic container and a method for producing an inner barrier film-coated plastic container. In particular, the present invention relates to an apparatus and a method for forming a barrier film for improving the gas barrier property of a plastic container on the inner surface of the plastic container.
[0002]
[Prior art]
Attempts have been made to increase the added value of the container by coating a thin film on the inner or outer surface of the container. For example, the chemical resistance of the container is improved, and the rate at which oxygen or carbon dioxide gas permeates the container wall is reduced.
[0003]
By improving the chemical resistance, a strong acid or alkali can be applied to a glass container having heat resistance rather than resin. In addition, the gas barrier property is improved by reducing the permeation rate of oxygen and carbon dioxide, and it becomes possible to fill a resin container with a beverage that is easily oxidized and has been filled in a glass container. .
[0004]
Patent Document 1 discloses a container whose chemical resistance is improved by coating diamond-like carbon or diamond, which will be described below, and an apparatus for manufacturing the same. That is, a cylindrical cathode to which a high frequency power source or a DC power source is connected and a grounded anode are installed inside a reaction chamber having a source gas introduction hole and an exhaust hole. A heater (not shown) is embedded in the anode. An opening is provided at one end of the cylindrical cathode in the axial direction, and an instrument is installed in the internal space of the cathode.
[0005]
In such a manufacturing apparatus, after exhausting the atmosphere in the reaction chamber, the heater is energized to heat the instrument. Subsequently, when high frequency power or DC power is applied to the cylindrical cathode while flowing the raw material gas, a discharge is generated in the space between the cathode and the anode, and plasma is generated in the space. The source gas is decomposed by the plasma, and the decomposed film-forming species are diffused. When the source gas reaches the inner surface of the instrument, it is deposited there, and the thin film is coated.
[0006]
Patent Document 2 discloses a container manufacturing apparatus with improved gas barrier properties described below. That is, a vacuum boundary is formed by the external electrode, the external electrode canopy portion, and the insulating plate that are connected to the high-frequency power source via the matching box. A flow path through which cooling water flows is provided on the inner surface of the external electrode, and a plastic outer cylinder is provided on the inner surface side of the flow path. Inside the outer cylinder, a plastic container is further provided with an internal electrode connected to the source gas supply pipe in a form inserted into the container. The supply pipe and the internal electrode communicate with each other inside, and the communicating point communicates with a gas supply port. The inner surface shape of the plastic outer cylinder is similar to the outer shape of the plastic container, and there is a substantially uniform gap between the inner surface of the outer cylinder and the outer surface of the container.
[0007]
In such a manufacturing apparatus, when the source gas is introduced from the source gas supply pipe after the atmosphere in the plastic inner space is exhausted, the gas flows into the plastic container from the gas supply port and is exhausted from the exhaust port. When flowing cooling water and applying high frequency power from a high frequency power source, a discharge is generated in the plastic internal space, and plasma is generated. The cooling water flows so that the plastic container is not damaged by the heat generated during plasma generation. The source gas is decomposed by the plasma, and the decomposed film-forming species are diffused. When the source gas reaches the inner surface of the plastic container, it deposits there and coats the thin film.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-70059
[0009]
[Patent Document 2]
JP 2000-230064 A
[0010]
[Problems to be solved by the invention]
However, the above-described invention of Patent Document 1 has the following problems.
[0011]
In order to coat a diamond-like carbon or diamond film, it is necessary to heat the device to be coated. In the problem solving means, from room temperature to 900 ° C. is suitable, and in the examples and comparative examples, examples of 50 to 100 ° C. are described. When the instrument is a plastic container, damage such as container deformation is expected at several tens of degrees, so there is a problem that the types of instruments to be coated are limited.
[0012]
Further, the above-described invention of Patent Document 2 has the following problems.
[0013]
A flow path for flowing cooling water and a plastic outer cylinder must be provided, and the structure of the film forming apparatus is complicated and large, leading to an increase in cost.
[0014]
The source gas is supplied into the plastic container from a plurality of gas supply ports opened along the axial direction of the internal electrode, and is exhausted from the mouth of the plastic container. For this reason, the gas flow path in the plastic container is a space sandwiched between the internal electrode and the external electrode, and the space near the mouth of the plastic container has a larger conductance and promotes the gas flow from the gas blowing hole, The flow of gas from the gas blowout hole near the bottom of the container far from the mouth becomes slow and tends to stay. As a result, the medium gas near the bottom of the container is exposed to the plasma for a longer time than the gas near the mouth of the container, so the molecules that are bound by the gas phase reaction may become too large and become powdery. is there. The powdery substance is not coated as a thin film on the surface of the container, and becomes a foreign substance that accumulates thereon. The occurrence of such foreign matters is inconvenient in the following points.
[0015]
a). Even if a large number of powdery substances are deposited, there is a gap between them, so that the gas barrier effect as in the case of using a carbon film does not occur.
[0016]
b). Substances that can enter the beverage remain in the container.
[0017]
An object of the present invention is to provide an apparatus for forming a carbon film on the inner surface of a plastic container, which has a good film quality on the inner surface of the plastic container and can be coated with a carbon film having a uniform thickness.
[0018]
An object of this invention is to provide the manufacturing method of the plastic container by which the film | membrane quality was favorable and the carbon film which has a uniform film thickness was coated by the inner surface.
[0019]
An object of the present invention is to provide an apparatus for forming a carbon film on the inner surface of a plastic container, which has good film quality on the inner surface of the plastic container and can coat a carbon film having a uniform thickness at a high speed.
[0020]
An object of this invention is to provide the manufacturing method of the plastic container by which the carbon film with favorable film quality and uniform film thickness was coated on the inner surface at high speed.
[0021]
[Means for Solving the Problems]
An apparatus for forming a barrier film on an inner surface of a plastic container and a method for manufacturing an inner surface barrier film-coated plastic container according to the present invention have the following configurations.
[0030]
  1) an external electrode having a size that surrounds a plastic container that is an object to be treated;
  Inserted into the plastic container in the external electrode through the insulating member on the end surface of the external electrode on the side where the mouth of the container is located.Connected to the ground side to become an internal electrodeA gas supply mechanism;
  A high-frequency power source connected to the external electrode;
Comprising
  The gas supply mechanism has a double tube structure including an inner tube and an outer tube, the inner tube is used for gas exhaust, and the medium gas is supplied between the inner tube and the outer tube. A device for forming a barrier film on the inner surface of a plastic container is characterized in that a spiral slit is formed in the outer tube portion located in the plastic container.
[0031]
  2)1In manufacturing an inner barrier film-coated plastic container using the barrier film forming apparatus of
  (A) inserting a plastic container as an object to be processed into the external electrode;
  (B) A gas supply mechanism having a double tube structure comprising an inner tube and an outer tube and having a spiral slit formed in the outer tube portion of the external electrode on the side where the mouth of the container is located Inserting into the inside of the plastic container through an insulating member on the end surface;
  (C) After exhausting the gas inside and outside the container through the inner pipe of the gas supply mechanism, a medium gas is supplied between the inner pipe and the outer pipe of the gas supply mechanism, and the medium gas is supplied from the spiral slit of the outer pipe. Blowing out as a swirl flow into the plastic container to raise the inside of the plastic container, and setting the inside of the exhaust pipe including the plastic container to a predetermined gas pressure;
  (D) supplying high frequency power from a high frequency power source to the external electrode, generating plasma in the plastic container, dissociating the medium gas by the plasma, and coating a barrier film on the inner surface of the plastic container;
A method for producing an inner barrier film-coated plastic container, comprising:
[0032]
  3) In the manufacturing method of the barrier film forming apparatus on the inner surface of the plastic container and the inner surface barrier film coated plastic container according to the present invention, the barrier film is carbon.With membraneTo beFeatures andTo do.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present inventionExamples examined by the present inventors in connection with the present inventionWill be described in detail with reference to the drawings.
[0034]
  (FirstExamination example)
  FIG. 1 shows the firstExamination exampleFIG. 2 is a cross-sectional view of the inner electrode bottom (cap) of FIG. 1.
[0035]
A cylindrical support member 2 having flanges 1 a and 1 b at the upper and lower ends is placed on an annular base 3. A cylindrical metal external electrode body 4 is disposed in the support member 2. A disk-shaped metal external electrode bottom member 5 is detachably attached to the bottom of the external electrode 4. The external electrode main body 4 and the external electrode bottom member 5 constitute a bottomed cylindrical external electrode 6 having a space of a size capable of installing a plastic container (for example, a plastic bottle) B that forms a carbon film. The disk-shaped insulator 7 is disposed between the base 3 and the external electrode bottom member 5.
[0036]
The external electrode bottom member 5, the disk-shaped insulator 7 and the base 3 are integrally moved up and down with respect to the external electrode main body 4 by a pusher (not shown) to open and close the bottom of the external electrode main body 4. To do.
[0037]
The annular insulating member 8 is placed on the upper surface of the external electrode 6 so that the upper surface of the annular insulating member 8 is flush with the upper flange 1 a of the cylindrical support member 2. A gas exhaust pipe 10 having upper and lower flanges 9 a and 9 b is placed on the upper flange 1 a of the support member 2 and the upper surface of the annular insulating member 8. The exhaust pipe 10 is grounded. The gas exhaust pipe 10 is fixed to the support member 2 by screwing screws (not shown) from the lower flange 9 b of the exhaust pipe 10 to the upper flange 1 a of the support member 2. Further, by screwing a screw (not shown) from the lower flange 9b of the exhaust pipe 10 through the annular insulating portion 8 to the main body 4 of the external electrode 6, the exhaust pipe 10 is connected to the annular insulating member 8 and the external electrode. 6 and the annular insulating member 8 is also fixed to the external electrode 6. The exhaust pipe 10 and the annular insulating member 8 and the external electrode 6 are fixed in a mounting structure in which the exhaust pipe 10 and the external electrode 6 are not electrically connected by screws. The branch gas exhaust pipe 11 is connected to the side wall of the gas exhaust pipe 10, and an exhaust facility such as a vacuum pump (not shown) is attached to the other end. The lid 12 is attached to the upper flange 9 a of the exhaust pipe 10.
[0038]
For example, a high frequency power source 13 that outputs high frequency power having a frequency of 13.56 MHz is connected to the main body 4 of the external electrode 6 through a cable 14 and a power supply terminal 15. The matching unit 16 is interposed in the cable 15 between the high-frequency power source 13 and the power supply terminal 15.
[0039]
The gas supply pipe 17 passes through the lid 12 and is inserted through the gas exhaust pipe 10 into a portion corresponding to the mouth of the plastic bottle B in the main body 4 of the external electrode 6. The substantially cylindrical internal electrode 18 is arranged in the plastic bottle B inserted into the external electrode 6 over almost the entire length in the longitudinal direction of the plastic bottle B, and its upper end is at the lower end of the gas supply pipe 17. It is detachably attached.
[0040]
The internal electrode 18 has a gas channel 19 through which a medium gas flows in a central axis. A cylindrical cap 20 made of metal is detachably attached to the bottom of the internal electrode 18. The cap 20 has a gas retention chamber 21 communicating with the gas flow path 19, and a plurality of, for example, four gas blowing holes 22 are opened on the side walls at an angle of 90 °. As shown in FIGS. 1 and 2, the four gas blowing holes 22 are opened in a substantially tangential direction with respect to the central axis of the internal electrode 18 on the side wall of the cap 20.
[0041]
The diameter of the internal electrode 18 is set to be equal to or smaller than the diameter of the cap of the plastic bottle B, and the length is set such that it can be inserted over almost the entire length in the longitudinal direction of the plastic bottle B. As a guide for the length, the ratio of the plastic bottle B to the total length is set to about {1-D / (2L)}. Here, D represents the inner diameter of the plastic bottle, L represents the total length of the plastic bottle, and L> (D / 2).
[0042]
The internal electrode 18 is made of a heat-resistant metal material such as tungsten or stainless steel, but may be made of aluminum. If the surface of the internal electrode 18 is smooth, the carbon film deposited on the surface of the internal electrode 18 may be easily peeled off. For this reason, it is preferable that the surface of the internal electrode 18 is previously sandblasted to increase the surface roughness and make it difficult to peel off the carbon film deposited on the surface.
[0043]
Next, a method for manufacturing an inner surface carbon film coated plastic container will be described using the carbon film forming apparatus shown in FIG.
[0044]
The external electrode bottom member 5, the disk-like insulator 7 and the base 3 are removed by a pusher (not shown) to open the bottom of the external electrode body 4. Subsequently, after inserting a plastic container, for example, a plastic bottle B from the bottom side of the external electrode body 4 opened from the mouth side of the bottle B, the external electrode bottom member 5 is placed on the bottom side of the external electrode body 4 by a pusher (not shown). By attaching the disk-shaped insulator 7 and the base 3 in this order, the plastic bottle B is placed in the internal space of the external electrode 6 composed of the external electrode main body 4 and the external electrode bottom member 5 as shown in FIG. Store. At this time, the plastic bottle B is communicated with the exhaust pipe 10 through its mouth.
[0045]
Next, the gas inside and outside the exhaust pipe 19 and the PET bottle B is exhausted through the branch exhaust pipe 10 and the exhaust pipe 11 by an exhaust means (not shown). Subsequently, the medium gas is supplied to the internal electrode 18 through the gas supply pipe 17. The medium gas supplied to the internal electrode 18 flows through the gas flow path 19, reaches the gas retention chamber 21 of the cap 20 at the bottom of the internal electrode 18, and enters a plurality of, for example, four gas blowing holes 22 into the plastic bottle B. Blown out. At this time, as shown in FIGS. 1 and 2, the four gas blowing holes 22 are opened in a direction substantially tangential to the central axis of the internal electrode 18 on the side wall of the cap 20. As shown in FIG. 3, the medium gas blown out from the gas becomes a swirl flow 23 and rises toward the mouth of the plastic bottle B. Thereafter, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic bottle B is set to a predetermined gas pressure.
[0046]
Next, high frequency power having a frequency of 13.56 MHz, for example, is supplied from the high frequency power supply 13 to the main body 4 of the external electrode 6 through the cable 14, the matching unit 16, and the power supply terminal 15. At this time, plasma is generated around the internal electrode 18. Due to the generation of the plasma, the medium gas is dissociated by the plasma, and the inner surface of the PET bottle B in the external electrode 6 is coated with a uniform carbon film with a uniform thickness.
[0047]
After the thickness of the carbon film reaches a predetermined film thickness, the supply of the high frequency power from the high frequency power supply 13 is stopped, the supply of the medium gas is stopped, the residual gas is exhausted, and the exhaust of the gas is stopped. , Nitrogen, rare gas, air, or the like is supplied into the plastic bottle B through the gas supply pipe 17 through the gas flow path 19 and the gas blowing hole 22 of the internal electrode 18, and the inside and outside of the plastic bottle B are returned to the atmospheric pressure. Remove the carbon film-coated PET bottle. Thereafter, the plastic bottle B is exchanged according to the above-described order, and the next plastic bottle coating operation is started.
[0048]
The medium gas is basically hydrocarbon, for example, alkanes such as methane, ethane, propane, butane, pentane and hexane; alkenes such as ethylene, propylene, butene, pentene and butadiene; alkynes such as acetylene; benzene Aromatic hydrocarbons such as toluene, xylene, indene, naphthalene and phenanthrene; cycloparaffins such as cyclopropane and cyclohexane; cycloolefins such as cyclopentene and cyclohexene; oxygen-containing hydrocarbons such as methyl alcohol and ethyl alcohol; Nitrogen-containing hydrocarbons such as methylamine, ethylamine and aniline can be used, and other carbon monoxide and carbon dioxide can also be used.
[0049]
The high frequency power is generally 13.56 MHz and 100 to 1000 W, but is not limited thereto. The application of these electric powers may be continuous or intermittent (pulsed).
[0050]
  1stExamination exampleAccording to FIG. 3, the medium gas is blown into the plastic bottle B from the plurality of gas blowing holes 22 which are opened substantially in the tangential direction with respect to the central axis of the internal electrode 18 on the side wall of the cap 20 at the bottom of the internal electrode 18. As shown, a swirl flow 23 of the medium gas can be formed in the plastic bottle B. For this reason, it is possible to forcibly create a gas flow from the bottom of the plastic bottle B toward the mouth, and to prevent a gas stagnant portion from being generated in the plastic bottle B. As a result, when plasma is generated around the internal electrode 18, the plasma can be exposed to a medium gas extending from the vicinity of the bottom of the PET bottle B to the mouth for a uniform time, and generation of powdery substances can be prevented. The inner surface of the PET bottle B can be coated with a carbon film having a uniform film thickness with good film quality without mixing this powdery substance.
[0051]
  Therefore, the firstExamination exampleTherefore, it is possible to manufacture an inner surface carbon film-coated PET bottle with excellent barrier properties that prevents permeation of oxygen from the outside and permeation of carbon dioxide from the inside (for example, carbonated drinking water).
[0052]
  (SecondExamination example)
  FIG. 4 shows the secondExamination exampleIt is sectional drawing which shows the carbon film formation apparatus to the plastic container inner surface which concerns on. Note that the first described above with reference to FIG.Examination exampleThe same members as in FIG. 1 referred to in FIG.
[0053]
In this carbon film forming apparatus, a bias power source 24 is connected to the external electrode body 4 of the external electrode 6 through a cable 25 and a power supply terminal 26. The matching unit 27 is interposed in the cable 25 between the bias power source 24 and the power supply terminal 26.
[0054]
The lid 12, which has an insulating ring 28 at the center and is grounded, is airtightly fixed to the upper flange 9 a of the gas exhaust pipe 10. The casing 29 is attached on the lid body 12.
[0055]
  The gas supply pipe 17 having the internal electrode 18 detachably attached to the lower end also serves as a terminal for high-frequency power, penetrates the insulating ring 28 of the lid 12 from the inside of the casing 29, and passes through the gas exhaust pipe 10. The external electrode 6 is inserted into the main body 4 (in the portion corresponding to the central portion of the plastic bottle B to be inserted). The upper end of the gas supply pipe 17 is connected to the lower end of a gas introduction pipe 30 inserted through the housing 29 from the outside via an insulating joint 31. The internal electrode 18 is the first electrode.Examination exampleAs described above, the gas flow path 19 through which the medium gas flows is cut out in the central axis, and a cylindrical cap 20 made of metal is detachably attached to the bottom. The cap 20 has a gas retention chamber 21 communicating with the gas flow path 19, and a plurality of, for example, four gas blowing holes 22 are opened on the side walls at an angle of 90 °. As shown in FIGS. 1 and 2, the four gas blowing holes 22 are opened in a substantially tangential direction on the side wall of the cap 20 with respect to the central axis of the internal electrode 18.
[0056]
The flange pipe 32 and the earth shield pipe 33 connected to the lower end of the flange pipe 32 are the gas located in the portion corresponding to the central portion of the plastic bottle B in the main body 4 of the gas exhaust pipe 10 and the external electrode 6. It arrange | positions so that the supply pipe | tube 17 part may be covered. The earth shield pipe 33 is located from the gas exhaust pipe 10 near the mouth of the plastic bottle B to a location corresponding to the central part of the plastic bottle B. The upper end of the flange tube 32 is connected to the back surface of the lid 12. That is, the earth shield tube 33 is connected to the lid body 12 grounded through the flange tube 32.
[0057]
The high-frequency power source 34 is connected to the side surface of the gas supply pipe 17 that also serves as a terminal for high-frequency power through a cable 35 and a power supply terminal 36. The matching unit 37 is interposed in the cable 35 between the high-frequency power source 34 and the power supply terminal 36.
[0058]
Next, a method for producing an inner surface carbon film-coated plastic container will be described using the carbon film forming apparatus shown in FIG.
[0059]
The external electrode bottom member 5, the disk-like insulator 7 and the base 3 are removed by a pusher (not shown) to open the bottom of the external electrode body 4. Subsequently, after inserting a plastic container, for example, a plastic bottle B from the bottom side of the external electrode body 4 opened from the mouth side of the bottle B, the external electrode bottom member 5 is placed on the bottom side of the external electrode body 4 by a pusher (not shown). By attaching the disk-shaped insulator 7 and the base 3 in this order, the plastic bottle B is placed in the internal space of the external electrode 6 including the external electrode body 4 and the external electrode bottom member 5 as shown in FIG. Store. At this time, the plastic bottle B is communicated with the exhaust pipe 10 through its mouth.
[0060]
Next, gas inside and outside the exhaust pipe 10 and the PET bottle B is exhausted through the branch exhaust pipe 11 and the exhaust pipe 10 by an exhaust means (not shown). Subsequently, the medium gas is supplied to the internal electrode 18 through the gas introduction pipe 30 and the gas supply pipe 17. The medium gas supplied to the internal electrode 18 flows through the gas flow path 19, reaches the gas retention chamber 21 of the cap 20 at the bottom of the internal electrode 18, and enters a plurality of, for example, four gas blowing holes 22 into the plastic bottle B. Blown out. At this time, as shown in FIGS. 1 and 2, the four gas blowing holes 22 are opened in a direction substantially tangential to the central axis of the internal electrode 18 on the side wall of the cap 20. The medium gas blown out from the gas becomes a swirl flow 23 as shown in FIG. 3 described above and rises toward the mouth of the plastic bottle B. Thereafter, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic bottle B is set to a predetermined gas pressure.
[0061]
Next, bias power is supplied from the bias power source 24 to the external electrode 6 through the cable 25, the matching unit 27 and the power supply terminal 26. Thereafter, or at the same time, high-frequency power is supplied from the high-frequency power source 34 to the gas supply pipe 17 through the cable 35, the matching unit 37 and the power supply terminal 36, and the high-frequency power is supplied to the internal electrode 18 through the gas supply pipe 17. . At this time, plasma is generated around the internal electrode 18. Further, since the exhaust pipe 10 located above the external electrode 6 is grounded, the bias voltage is directed from the external electrode 6 toward the internal electrode 18 with the exhaust pipe 10 as a reference potential, that is, to the generated plasma. Can be applied.
[0062]
As a result, a) When high-frequency power is used, a higher electron density than that of high-frequency power can be obtained particularly under low gas pressure conditions, so that the collision frequency with the medium gas increases and the film-forming seed density can be increased. B) By adjusting the bias power, the potential difference from the plasma potential can be made variable, so that the ion energy incident on the inner surface of the PET bottle B can be adjusted. C) The ion density is proportional to the electron density. Thus, the ion flux incident on the inner surface of the plastic bottle B can be controlled. Bias power was applied to the film-forming species obtained when the medium gas was dissociated by the plasma by the generation of the plasma and the drawing of the plasma to the external electrode 6 by applying the bias voltage to the external electrode 6. The external electrode 6 can be drawn into the inner surface of the plastic bottle B, and a uniform carbon film with a uniform thickness can be coated at a high speed.
[0063]
After the thickness of the carbon film reaches a predetermined thickness, supply of bias power and high frequency power from the bias power source 24 and high frequency power source 34 is stopped, supply of medium gas is stopped, and residual gas is exhausted. After the gas exhaust is stopped, nitrogen, rare gas, air or the like is supplied from the gas introduction pipe 30 through the gas supply pipe 17 through the gas flow path 19 of the internal electrode 18 and the gas blowout hole 22 of the cap 20. The inside of this PET bottle B is returned to atmospheric pressure, and the inner surface carbon film-coated PET bottle is taken out. Thereafter, the plastic bottle B is exchanged according to the above-described order, and the next plastic bottle coating operation is started.
[0064]
  As the medium gas, firstExamination exampleThe same as described in the above can be used.
[0065]
The high-frequency power is generally defined as 30 to 300 MHz, but is not limited thereto. Moreover, the application of these electric powers may be continuous or intermittent (pulsed).
[0066]
The bias power is generally 13.56 MHz and 100 to 1000 W, but is not limited thereto. Further, the bias power may be applied continuously or intermittently (pulsed).
[0067]
  2ndExamination exampleAccording to FIG. 3, the medium gas is blown into the plastic bottle B from the plurality of gas blowing holes 22 which are opened substantially in the tangential direction with respect to the central axis of the internal electrode 18 on the side wall of the cap 20 at the bottom of the internal electrode 18. As shown, a swirl flow 23 of the medium gas can be formed in the plastic bottle B. For this reason, it is possible to forcibly create a gas flow from the bottom of the plastic bottle B toward the mouth, and to prevent a gas stagnant portion from being generated in the plastic bottle B. As a result, when plasma is generated around the internal electrode 18, the plasma can be exposed to a medium gas extending from the vicinity of the bottom of the PET bottle B to the mouth for a uniform time, and generation of powdery substances can be prevented. The inner surface of the PET bottle B can be coated with a carbon film having a uniform film thickness with good film quality without mixing this powdery substance.
[0068]
In addition, a bias power is applied to the film-forming species obtained when the medium gas is dissociated by the plasma by generating plasma and applying the bias voltage to the external electrode 6 to attract the plasma to the external electrode 6. It can be drawn into the inner surface of the plastic bottle B in the external electrode 6, and can coat a uniform carbon film with a uniform thickness at a high speed.
[0069]
Therefore, an inner surface carbon film-coated PET bottle with excellent barrier properties that prevents the permeation of oxygen from the outside and the permeation of carbon dioxide from the inside (for example, carbonated drinking water) can be produced more mass-produced.
[0070]
Further, when high-frequency power is supplied from the high-frequency power source 34 to the gas supply pipe 17, discharge is performed between the grounded exhaust pipe 10, and unnecessary plasma is similarly generated in the exhaust pipe 10 to generate carbon. The coating efficiency of the film is reduced. For this reason, the earth shield pipe 33 is arranged on the outer periphery of the gas supply pipe 17 so as to be positioned in the gas exhaust pipe 10 in the vicinity of the mouth of the plastic bottle B, and the earth shield pipe 33 is a flange that supports the earth shield pipe 33. By grounding through the pipe 32, even if high-frequency power is supplied to the gas supply pipe 17 penetrating the earth shield pipe 33, unnecessary plasma is generated in the exhaust pipe 10 which is the exhaust path of the medium gas. Can be prevented. As a result, it is possible to prevent consumption of high-frequency power accompanying unnecessary plasma generation, so that regular plasma generation efficiency in the PET bottle B can be increased and the coating speed of the carbon film can be improved.
[0071]
  The first and secondExamination exampleThen, the number of gas blowing holes is four, but it may be two, three, five or more. Further, although the plurality of gas blowing holes are opened substantially tangentially to the central axis of the cap side wall, the plurality of gas blowing holes may be opened tangentially to the central axis of the cap side wall.
[0072]
  (ThirdExamination example)
  FIG. 5 shows the thirdExamination exampleIt is sectional drawing which shows the carbon film formation apparatus to the plastic container inner surface which concerns on.
[0073]
A cylindrical support member 42 having flanges 41 a and 41 b at the upper and lower ends is placed on an annular base 43. A cylindrical metal external electrode body 44 is disposed in the support member 42. A disk-shaped metal external electrode bottom member 45 is detachably attached to the bottom of the external electrode 44. The external electrode main body 44 and the external electrode bottom member 45 constitute a bottomed cylindrical external electrode 46 having a space of a size capable of installing a plastic container (for example, a plastic bottle) B that forms a carbon film. A disk-shaped insulator 47 is disposed between the base 43 and the external electrode bottom member 45.
[0074]
The external electrode bottom member 45, the disk-shaped insulator 47, and the base 43 are moved up and down integrally with the external electrode body 4 by a pusher (not shown) to open and close the bottom of the external electrode body 4. To do.
[0075]
A cylindrical spacer 49 made of a dielectric material having a cavity 48 formed by combining a cylinder and a truncated cone corresponding to the mouth and shoulder of the plastic bottle B inserted therein is the main body of the external electrode 46. 44 is inserted in the upper part. The spacer 49 is fixed by a screw (not shown) screwed from an annular insulating member, which will be described later, placed on the spacer 49. By inserting and fixing the columnar spacer 49 to the upper part of the main body 44 in the external electrode 46 in this way, when the plastic bottle B is inserted from the bottom side of the external electrode main body 44, the mouth and shoulder of the plastic bottle B are inserted. The portion is accommodated in the cavity 48 of the spacer 49, and the other plastic bottle B portion is accommodated in the external electrode 46.
[0076]
Examples of the dielectric material constituting the spacer 49 include plastic or ceramic. Various plastics can be used, and a fluorine-based resin such as polytetrafluoroethylene having a low high-frequency loss and excellent heat resistance is particularly preferable. As the ceramic, alumina, steatite with low high-frequency loss, or Macor with high machinability is preferable.
[0077]
The annular insulating member 50 is placed on the upper surface of the external electrode 46 so that the upper surface of the annular insulating member 50 is flush with the upper flange 41 a of the cylindrical support member 42. A gas exhaust pipe 52 having upper and lower flanges 51 a and 51 b is placed on the upper flange 41 a of the support member 42 and the upper surface of the annular insulating member 50. The exhaust pipe 52 is grounded. The gas exhaust pipe 52 is fixed to the support member 42 by screwing screws (not shown) from the lower flange 51 b of the exhaust pipe 52 to the upper flange 41 a of the support member 42. Further, by screwing a screw (not shown) from the lower flange 51b of the exhaust pipe 52 through the annular insulating portion 50 to the main body 44 of the external electrode 46, the exhaust pipe 52 is connected to the annular insulating member 50 and the external electrode. The annular insulating member 50 is also fixed to the external electrode 46. The exhaust pipe 52 and the annular insulating member 50 and the external electrode 46 are fixed to each other by a mounting structure in which the exhaust pipe 52 and the external electrode 46 are not electrically connected by screws. The branch gas exhaust pipe 53 is connected to the side wall of the gas exhaust pipe 52, and an exhaust facility such as a vacuum pump (not shown) is attached to the other end. The lid 54 is attached to the upper flange 51a of the exhaust pipe 52.
[0078]
For example, a high frequency power supply 55 that outputs high frequency power with a frequency of 13.56 MHz is connected to the main body 44 of the external electrode 46 through a cable 56 and a power supply terminal 57. The matching unit 58 is interposed in the cable 56 between the high frequency power supply 55 and the power supply terminal 57.
[0079]
The gas supply pipe 59 passes through the lid 54 and is inserted through the gas exhaust pipe 52 into a portion corresponding to the mouth portion of the plastic bottle B in the main body 44 of the external electrode 46. The substantially cylindrical internal electrode 60 is disposed in the plastic bottle B inserted into the external electrode 46 over almost the entire length in the longitudinal direction of the plastic bottle B, and the upper end thereof is the lower end of the gas supply pipe 59. It is detachably attached.
[0080]
The internal electrode 60 has a gas channel 61 through which a medium gas flows in a central axis. A cylindrical cap 62 made of metal is detachably attached to the bottom of the internal electrode 60. In this cap 62, a gas retention chamber 63 communicating with the gas flow path 61 is hollowed out, and a plurality of, for example, four gas blowing holes 64 are opened on the side wall at an angle of 90 °. As shown in FIG. 5, the four gas blowing holes 64 are opened in a substantially tangential direction with respect to the central axis of the internal electrode 60 on the side wall of the cap 62.
[0081]
The diameter of the internal electrode 60 is set to be equal to or smaller than the diameter of the cap of the plastic bottle B, and the length is set such that it can be inserted over almost the entire length in the longitudinal direction of the plastic bottle B. As a guide for the length, the ratio of the plastic bottle B to the total length is set to about {1-D / (2L)}. Here, D represents the inner diameter of the plastic bottle, L represents the total length of the plastic bottle, and L> (D / 2).
[0082]
The internal electrode 60 is made of a heat-resistant metal material such as tungsten or stainless steel, but may be made of aluminum. Further, if the surface of the internal electrode 60 is smooth, the carbon film deposited on the surface of the internal electrode 60 may be easily peeled off. For this reason, it is preferable that the surface of the internal electrode 60 be previously sandblasted to increase the surface roughness and make it difficult to peel off the carbon film deposited on the surface.
[0083]
Next, a method for producing an inner surface carbon film-coated plastic container will be described using the carbon film forming apparatus shown in FIG.
[0084]
The external electrode bottom member 45, the disk-shaped insulator 47, and the base 43 are removed by a pusher (not shown) to open the bottom of the external electrode main body 44. Subsequently, after the plastic container, for example, the plastic bottle B is inserted from the bottom side of the external electrode main body 44 opened from the mouth side of the bottle B, the external electrode bottom member 45 is placed on the bottom side of the external electrode main body 44 by a pusher (not shown). By attaching the disk-shaped insulator 47 and the base 43 in this order, as shown in FIG. 5, the shoulder portion from the mouth of the plastic bottle B enters the cavity 48 of the cylindrical spacer 49 made of a dielectric material. The bottom side of the bottle B from the shoulder is accommodated in the external electrode 46. At this time, the plastic bottle B is communicated with the exhaust pipe 52 through its mouth.
[0085]
Next, the gas inside and outside the exhaust pipe 52 and inside and outside the plastic bottle B is exhausted through the branch exhaust pipe 53 and the exhaust pipe 52 by an exhaust means (not shown). Subsequently, the medium gas is supplied to the internal electrode 60 through the gas supply pipe 59. The medium gas supplied to the internal electrode 60 flows through the gas flow path 61, reaches the gas retention chamber 63 of the cap 62 at the bottom of the internal electrode 60, and enters a plurality of, for example, four gas blowing holes 64 into the plastic bottle B. Blown out. At this time, since the four gas blowing holes 64 are opened in a direction substantially tangential to the central axis of the internal electrode 60 on the side wall of the cap 62 as shown in FIG. 5 and FIG. The medium gas blown out from the hole 64 rises toward the mouth of the plastic bottle B as a swirling flow as shown in FIG. Thereafter, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic bottle B is set to a predetermined gas pressure.
[0086]
Next, high frequency power having a frequency of 13.56 MHz, for example, is supplied from the high frequency power supply 55 to the main body 44 of the external electrode 46 through the cable 56, the matching unit 58 and the power supply terminal 57. At this time, plasma is generated around the internal electrode 60. Due to the generation of such plasma, the medium gas is dissociated by the plasma, and a uniform carbon film having a uniform thickness is coated on the inner surfaces of the external electrode 46 and the PET bottle B in the spacer 49.
[0087]
After the thickness of the carbon film reaches a predetermined thickness, the supply of the high frequency power from the high frequency power supply 55 is stopped, the supply of the medium gas is stopped, the residual gas is exhausted, and the exhaust of the gas is stopped. , Nitrogen, rare gas, air, or the like is supplied into the PET bottle B through the gas supply pipe 59 through the gas flow path 61 of the internal electrode 60 and the gas blowing hole 64 of the cap 62, and the inside and outside of the PET bottle B are brought to atmospheric pressure. Return and remove the inner carbon film-coated PET bottle. Thereafter, the plastic bottle B is exchanged according to the above-described order, and the next plastic bottle coating operation is started.
[0088]
  As the medium gas, firstExamination exampleThe same as can be used.
[0089]
The high frequency power is generally 13.56 MHz and 100 to 1000 W, but is not limited thereto. Moreover, the application of these electric powers may be continuous or intermittent (pulsed).
[0090]
  3rdExamination exampleAccording to the above, the medium gas is opened on the side wall of the cap 62 at the bottom of the internal electrode 60 in a direction substantially tangential to the central axis of the internal electrode 60 and is blown out into the plastic bottle B from the plurality of gas blowing holes 64 as described above. As shown in FIG. 3, a swirling flow of the medium gas can be formed in the plastic bottle B. For this reason, it is possible to forcibly create a gas flow from the bottom of the plastic bottle B toward the mouth, and to prevent a gas stagnant portion from being generated in the plastic bottle B. As a result, when plasma is generated around the internal electrode 60, the plasma can be exposed to the medium gas extending from the vicinity of the bottom of the PET bottle B to the mouth for a uniform time, and generation of powdery substances can be prevented. Therefore, the inner surface of the PET bottle B can be coated with a carbon film having a uniform film thickness with good film quality without mixing powdery substances.
[0091]
Further, by inserting and fixing a cylindrical spacer 49 made of a dielectric material having a cavity 48 on the upper part of the external electrode 46, not only the inner surface of the PET bottle B from the shoulder to the bottom side in the generation of the plasma. A carbon film having a uniform thickness can be coated on the inner surface of the shoulder portion from the mouth portion of the plastic bottle B facing the spacer 49 made of the dielectric material.
[0092]
Therefore, the inner surface carbon film-coated PET bottle having excellent barrier properties that prevents the permeation of oxygen from the outside and the permeation of carbon dioxide from the inside (for example, carbonated drinking water) can be mass-produced.
[0093]
In addition, the shape of the member covering the mouth portion and the shoulder portion of the plastic bottle B is complicated, but by forming the spacer 49 corresponding to these members with a dielectric material such as plastic capable of injection molding, Compared to the conventional case where all the members including these members are constituted by external electrodes, it can be manufactured easily. Furthermore, the entire apparatus can be reduced in weight as compared with the case where all of these members including the external electrodes are made of a conductive material such as metal as in the prior art.
[0094]
Further, by forming the spacer 49 from a dielectric material such as plastic or soft ceramic, it is possible to prevent the occurrence of scratches at the complicated mouth portion and shoulder portion of the plastic bottle B when they contact each other. it can.
[0095]
  (In the third study exampleImplementationExample)
  As the internal electrode 18, four gas blowing holes 22 having an inner diameter of 1 mm are opened in a substantially tangential direction at an angle of 90 ° at the bottom of a stainless steel sealed tube having an outer diameter of 16 mm and a length of 163 mm shown in FIGS. A stainless steel cap 20 was used.
[0096]
The internal electrode 18 is inserted into a plastic bottle B accommodated in the external electrode 6 shown in FIG.₂H₂The inner surface of the PET bottle B is coated with a carbon film under the conditions of gas, gas flow rate of 100 sccm, 200 sccm, and 300 sccm, gas pressure of the PET bottle B and the exhaust pipe 10 of 100 mTorr, and high frequency of 13.56 MHz supplied from a high frequency power source. did.
[0097]
Each PET bottle B coated with the carbon film was cut in the axial direction, and the carbon film on the inner surface was observed with an SEM. As a result, none of the PET bottles B was mixed with powdery substances in the carbon film.
[0098]
  (4thExamination example)
  FIG. 6 shows the fourthExamination exampleIt is sectional drawing which shows the carbon film formation apparatus to the plastic container inner surface which concerns on. The third described above with reference to FIG.Examination exampleThe members similar to those in FIG. 5 referred to in FIG.
[0099]
In this carbon film forming apparatus, a bias power source 65 is connected to the external electrode body 44 of the external electrode 46 through a cable 66 and a power supply terminal 67. The matching unit 68 is interposed in the cable 66 between the bias power source 65 and the power supply terminal 67.
[0100]
A lid 54 having an insulating ring 69 at the center and grounded is hermetically fixed to the upper flange 51 a of the gas exhaust pipe 52. The casing 70 is attached on the lid 54.
[0101]
  The gas supply pipe 59 having the internal electrode 60 detachably attached to the lower end also serves as a terminal for high-frequency power, penetrates the insulating ring 69 of the lid body 54 from the inside of the casing 70, and passes through the gas exhaust pipe 52. It is inserted into a spacer 49 in the external electrode 46. The upper end of the gas supply pipe 59 is connected to the lower end of a gas introduction pipe 71 inserted through the housing 70 from the outside via an insulating joint 72. The internal electrode 60 is the third electrode.Examination exampleAs described above, the gas flow path 61 through which the medium gas flows is cut out in the central axis, and a cylindrical cap 63 made of metal is detachably attached to the bottom. In this cap 62, a gas retention chamber 63 communicating with the gas flow path 61 is hollowed out, and a plurality of, for example, four gas blowing holes 64 are opened on the side wall at an angle of 90 °. As shown in FIG. 6, the four gas blowing holes 64 are opened in a substantially tangential direction with respect to the central axis of the internal electrode 60 on the side wall of the cap 62.
[0102]
A flange pipe 73 and an earth shield pipe 74 connected to the lower end of the flange pipe 73 are arranged so as to cover the gas exhaust pipe 52 and the gas supply pipe 59 portion located in the spacer 49. The earth shield pipe 74 is located in the spacer 49 and in the gas exhaust pipe 52 in the vicinity of the spacer 49. The upper end of the flange tube 73 is connected to the back surface of the lid 54. In other words, the earth shield tube 74 is connected to the lid 54 that is grounded through the flange tube 73.
[0103]
The high-frequency power source 75 is connected to the side surface of the gas supply pipe 59 that also serves as a terminal for high-frequency power through a cable 76 and a power supply terminal 77. The matching unit 78 is interposed in the cable 76 between the high-frequency power source 75 and the power supply terminal 77.
[0104]
Next, a method for manufacturing an inner surface carbon film-coated plastic container will be described using the carbon film forming apparatus shown in FIG.
[0105]
The external electrode bottom member 45, the disk-shaped insulator 47, and the base 43 are removed by a pusher (not shown) to open the bottom of the external electrode main body 44. Subsequently, after the plastic container, for example, the plastic bottle B is inserted from the bottom side of the external electrode main body 44 opened from the mouth side of the bottle B, the external electrode bottom member 45 is placed on the bottom side of the external electrode main body 44 by a pusher (not shown). By attaching the disk-shaped insulator 47 and the base 43 in this order, as shown in FIG. 6, the shoulder portion from the mouth of the plastic bottle B enters the cavity 48 of the cylindrical spacer 49 made of a dielectric material. The bottom side of the bottle B from the shoulder is accommodated in the external electrode 46. At this time, the plastic bottle B is communicated with the exhaust pipe 52 through its mouth.
[0106]
Next, the gas inside and outside the exhaust pipe 52 and inside and outside the plastic bottle B is exhausted through the branch exhaust pipe 53 and the exhaust pipe 52 by an exhaust means (not shown). Subsequently, the medium gas is supplied to the internal electrode through the gas introduction pipe 71 and the gas supply pipe 59. The medium gas supplied to the internal electrode 60 flows through the gas flow path 61, reaches the gas retention chamber 63 of the cap 62 at the bottom of the internal electrode 60, and enters a plurality of, for example, four gas blowing holes 64 into the plastic bottle B. Blown out. At this time, since the four gas blowing holes 64 are opened in a direction substantially tangential to the central axis of the internal electrode 60 on the side wall of the cap 62 as shown in FIG. 6 and FIG. The medium gas blown out from the hole 64 rises toward the mouth of the plastic bottle B as a swirling flow as shown in FIG. Thereafter, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic bottle B is set to a predetermined gas pressure.
[0107]
Next, bias power is supplied from the bias power source 65 to the external electrode 46 through the cable 66, the matching unit 68 and the power supply terminal 67. Thereafter, or simultaneously, high-frequency power is supplied from the high-frequency power source 75 to the gas supply pipe 59 through the cable 76, the matching unit 78, and the power supply terminal 77, and the high-frequency power is supplied to the internal electrode 60 through the gas supply pipe 59. . At this time, plasma is generated around the internal electrode 60. The earth shield pipe 74 is disposed on the outer periphery of the gas supply pipe 59 so as to be located in the spacer 49 and in the gas exhaust pipe 52 in the vicinity of the spacer 49, and is grounded through the flange pipe 73. With the earth shield tube 74 as a reference potential, a bias voltage can be applied from the external electrode 46 toward the internal electrode 60, that is, toward the generated plasma.
[0108]
As a result, a) When high-frequency power is used, a higher electron density than that of high-frequency power can be obtained particularly under low gas pressure conditions, so that the collision frequency with the medium gas increases and the film-forming seed density can be increased. B) By adjusting the bias power, the potential difference from the plasma potential can be made variable, so that the ion energy incident on the inner surface of the PET bottle B can be adjusted. C) The ion density is proportional to the electron density. Thus, the ion flux incident on the inner surface of the plastic bottle B can be controlled. Bias power is applied to the film-forming species obtained when the medium gas is dissociated by the plasma by generating plasma and applying the bias voltage to the external electrode 46 to draw the plasma into the external electrode 46. It can be drawn into the inner surface of the PET bottle B in the external electrode 46, and a uniform carbon film having a uniform thickness can be coated at a high speed.
[0109]
After the thickness of the carbon film reaches a predetermined film thickness, supply of bias power and high frequency power from the bias power source 65 and high frequency power source 75 is stopped, supply of medium gas is stopped, and residual gas is exhausted. After the gas exhaust is stopped, nitrogen, rare gas, air or the like is discharged from the gas introduction pipe 71 through the gas supply pipe 59 through the gas flow path 61 of the internal electrode 60 and the gas blowing hole 64 of the cap 62. The inside of this PET bottle B is returned to atmospheric pressure, and the inner surface carbon film-coated PET bottle is taken out. Thereafter, the plastic bottle B is exchanged according to the above-described order, and the next plastic bottle coating operation is started.
[0110]
  The medium gas is the firstExamination exampleThe same as described in the above can be used.
[0111]
The high-frequency power is generally defined as 30 to 300 MHz, but is not limited thereto. Moreover, the application of these electric powers may be continuous or intermittent (pulsed).
[0112]
The bias power is generally 13.56 MHz and 100 to 1000 W, but is not limited thereto. Further, the bias power may be applied continuously or intermittently (pulsed).
[0113]
  4thExamination exampleAccording to the above, the medium gas is opened on the side wall of the cap 62 at the bottom of the internal electrode 60 in a direction substantially tangential to the central axis of the internal electrode 60 and is blown out into the plastic bottle B from the plurality of gas blowing holes 64 as described above. As shown in FIG. 3, a swirling flow of the medium gas can be formed in the plastic bottle B. For this reason, it is possible to forcibly create a gas flow from the bottom of the plastic bottle B toward the mouth, and to prevent a gas stagnant portion from being generated in the plastic bottle B. As a result, when plasma is generated around the internal electrode 60, the plasma can be exposed to the medium gas extending from the vicinity of the bottom of the PET bottle B to the mouth for a uniform time, and generation of powdery substances can be prevented. The inner surface of the PET bottle B can be coated with a carbon film having a uniform film thickness with good film quality without mixing this powdery substance.
[0114]
Further, by inserting and fixing a cylindrical spacer 49 made of a dielectric material having a cavity 48 on the upper part of the external electrode 46, not only the inner surface of the PET bottle B from the shoulder to the bottom side in the generation of the plasma. A carbon film having a uniform thickness can be coated on the inner surface of the shoulder portion from the mouth portion of the plastic bottle B facing the spacer 49 made of the dielectric material.
[0115]
Furthermore, the bias power is applied to the film forming species obtained when the medium gas is dissociated by the plasma by generating the plasma and drawing the plasma into the external electrode 46 by applying a bias voltage to the external electrode 46. It can be drawn into the inner surface of the PET bottle B in the external electrode 46, and a uniform carbon film with a uniform thickness can be coated at a high speed.
[0116]
Therefore, an inner surface carbon film-coated PET bottle with excellent barrier properties that prevents the permeation of oxygen from the outside and the permeation of carbon dioxide from the inside (for example, carbonated drinking water) can be produced more mass-produced.
[0117]
Further, when high-frequency power is supplied from the high-frequency power source 75 to the gas supply pipe 59, discharge is performed between the grounded exhaust pipe 52, and unnecessary plasma is generated in the exhaust pipe 52 in the same manner. The coating efficiency of the film is reduced. For this reason, the earth shield pipe 74 is arranged on the outer periphery of the gas supply pipe 59 so as to be located in the gas exhaust pipe 52 in the vicinity of the mouth of the plastic bottle B, and the earth shield pipe 74 is a flange that supports the earth shield pipe 74. By grounding through the pipe 73, even if high-frequency power is supplied to the gas supply pipe 59 penetrating the earth shield pipe 74, unnecessary plasma is generated in the exhaust pipe 52, which is the exhaust path for the medium gas. Can be prevented. As a result, it is possible to prevent consumption of high-frequency power accompanying unnecessary plasma generation, so that regular plasma generation efficiency in the PET bottle B can be increased and the coating speed of the carbon film can be improved.
[0118]
Furthermore, the shape of the member covering the mouth and shoulder of PET bottle B is complicated, but by forming the spacer 49 corresponding to these members from a dielectric material such as plastic that can be injection molded, Compared to the conventional case where all the members including these members are constituted by external electrodes, it can be manufactured easily. In addition, the entire apparatus can be reduced in weight as compared with the conventional case where all of these members are formed of external electrodes with a conductive material such as metal. In addition, by forming the spacer 49 from a dielectric material such as plastic or soft ceramic, when the complicated mouth and shoulder of the plastic bottle B come into contact with each other, it is possible to prevent the spot from being damaged. Can do.
[0119]
  The third and fourthExamination exampleThen, the number of gas blowing holes is four, but it may be two, three, five or more. Further, although the plurality of gas blowing holes are opened substantially tangentially to the central axis of the cap side wall, the plurality of gas blowing holes may be opened tangentially to the central axis of the cap side wall.
[0120]
  The third and fourthExamination exampleThen, a cylindrical spacer 49 made of a dielectric material having a cavity 48 is inserted and fixed to the upper part of the external electrode 46 so as to correspond to the shoulder from the mouth of the plastic bottle B. From the shoulder of the plastic bottle B, Further, a thin film made of a dielectric material may be extended over the bottom.
[0121]
  (In the fourth study exampleImplementationExample)
  The internal electrode 18 is made of stainless steel, in which four gas blowing holes 22 having an inner diameter of 1 mm are opened in a substantially tangential direction at an angle of 90 ° at the bottom of a stainless steel sealed tube having an outer diameter of 16 mm and a length of 163 mm shown in FIG. A structure with a cap 20 attached thereto was used.
[0122]
The internal electrode 18 is inserted into a plastic bottle B accommodated in the external electrode 6 shown in FIG.₂H₂Gas, gas flow rate is 100 sccm, 200 sccm, and 300 sccm, gas pressure in the PET bottle B and the exhaust pipe 10 is 100 mTorr, high frequency supplied from the high frequency power source 34 is 100 MHz, and bias high frequency from the bias power source 24 is 13 MHz. Under the conditions, a carbon film was coated on the inner surface of the plastic bottle B.
[0123]
Each PET bottle B coated with the carbon film was cut in the axial direction, and the carbon film on the inner surface was observed with an SEM. As a result, none of the PET bottles B was mixed with powdery substances in the carbon film.
[0124]
  (Of the present inventionEmbodiment)
  FIG.Of the present inventionFIG. 8 is a perspective view showing the gas supply mechanism of FIG. 7, and FIG. 8 is a cross-sectional view showing the carbon film forming apparatus on the inner surface of the plastic container according to the embodiment.
[0125]
Cylindrical support members 82 having flanges 81 a and 81 b at the upper and lower ends are placed on an annular base 83. A storage member 84 in which a plastic container (for example, a plastic bottle) B that forms a carbon film is stored is disposed in the cylindrical support member 82 and the annular base 83.
[0126]
The storage member 84 corresponds to a cylindrical body 85 that surrounds the outer periphery of the plastic bottle B when the plastic bottle B is inserted, and a mouth and a shoulder when the plastic bottle B is inserted into the cylindrical body 85. A cylindrical spacer 87 made of a dielectric material having a hollow portion 86 which is arranged so as to be positioned and combined with a cylinder and a truncated cone, and a circle made of an insulating material arranged at the bottom of the cylindrical body 85 It consists of a plate-like bottom plate 88. The disk-shaped insulator 91 is disposed between the base 83 and the disk-shaped bottom plate 88.
[0127]
The cylindrical body 85 and the disk-shaped bottom plate 88 are made of a heat-resistant metal material such as tungsten or stainless steel, but may be made of aluminum.
[0128]
The base 83, the disk-shaped insulator 91, and the disk-shaped bottom plate 88 are integrally moved up and down with respect to the cylindrical body 85 by a pusher (not shown) to open and close the bottom of the cylindrical body 85. .
[0129]
The annular insulating member 92 is placed on the cylindrical body 85 and the spacer 87 so that the upper surface of the annular insulating member 92 is flush with the upper flange 81 a of the cylindrical support member 82.
[0130]
  The auxiliary gas exhaust pipe 94 having upper and lower flanges 93 a and 93 b is placed on the upper flange 81 a of the support member 82 and the upper surface of the annular insulating member 92. This exhaust pipe 94Is grounded. The auxiliary gas exhaust pipe 94 is fixed to the support member 82 by screwing screws (not shown) from the lower flange 93 b of the exhaust pipe 94 to the upper flange 81 a of the support member 82. Further, by screwing a screw (not shown) from the lower flange 93b of the auxiliary gas exhaust pipe 94 through the annular insulating portion 92 to the cylindrical body 85, the cylindrical body 85 and the outer cylinder are connected to the annular insulation. It is suspended from the member 92 and the auxiliary gas exhaust pipe 94. The branch gas exhaust pipe 95 is connected to the side wall of the auxiliary gas exhaust pipe 94, and an exhaust facility such as a vacuum pump (not shown) is attached to the other end.
[0131]
The high frequency power supply 96 is connected to the cylindrical body 85 through a cable 97 and a power supply terminal 98 as shown in FIG. The matching unit 99 is interposed in the cable 97 between the high-frequency power source 96 and the power supply terminal 98.
[0132]
The cylindrical body 85, the cable 97, the power supply terminal 98, and the high-frequency power source 96 to which the matching unit 99 is connected constitute a plasma generation mechanism.
[0133]
The grounded lid body 100 is airtightly fixed to the upper flange 93a of the gas exhaust pipe 94.
[0134]
  The gas supply mechanism 101GroundedPenetrate the lid 100And ground as an internal electrodeThe gas exhaust pipe 94 and the annular insulating member 92 are inserted into the spacer 87 (in the vicinity of the mouth of the plastic bottle B to be inserted) located near the upper portion in the cylindrical body 85. As shown in FIGS. 7 and 8, the gas supply mechanism 101 has a double tube structure including an inner tube 102 and an outer tube 103, and the inner tube 102 protrudes downward at the lower end thereof. The inner pipe 102 is used as a main gas exhaust pipe, and an exhaust facility such as a vacuum pump (not shown) is attached to the other end. A medium gas is supplied between the inner tube 102 and the outer tube 103. The outer tube 103 is formed with a spiral slit 104 at a portion located in the spacer 87.
[0135]
Next, a method for manufacturing an inner surface carbon film-coated plastic container will be described using the carbon film forming apparatus shown in FIG.
[0136]
The base 83, the disk-shaped insulator 91 and the disk-shaped bottom plate 88 are removed by a pusher (not shown) to open the bottom of the cylindrical body 85. Subsequently, after inserting a plastic container, for example, a plastic bottle B, into the bottom of the cylindrical body 85 opened from the mouth side, the disc-shaped bottom plate 88 and the disc are placed on the bottom side of the cylindrical body 85 by a pusher (not shown). By attaching the cylindrical insulator 91 and the base 83 in this order, the bottle is inserted into the hollow portion 86 of the cylindrical spacer 87 whose shoulder portion is made of a dielectric material from the mouth portion of the plastic bottle B as shown in FIG. The bottom side from the shoulder of B is accommodated in the cylindrical body 85 and the disc-shaped bottom plate 88. At this time, the vicinity of the lower part of the double pipe structure of the gas supply mechanism 101 is inserted into the mouth of the plastic bottle B.
[0137]
Next, the auxiliary gas exhaust pipe 94 is exhausted through the branch exhaust pipe 95 by an exhaust equipment (not shown). At the same time, the gas in the PET bottle B is exhausted through the inner pipe 102 of the gas supply mechanism 101 that functions as the main gas exhaust pipe by an exhaust system (not shown). Subsequently, the medium gas is blown out into the plastic bottle B through the tubular space between the inner tube 102 and the outer tube 103 of the gas supply mechanism 101. At this time, a spiral slit 104 is formed in the outer tube 103 located at the mouth of the plastic bottle B, and the inner tube 102 that exhausts gas at the lower end protrudes downward at the lower end. The medium gas thus formed becomes a swirl flow 105 as shown in FIG. 7, descends from the mouth of the plastic bottle B toward the inside, and then rises due to the exhaust action by the inner tube 102. Thereafter, the gas supply amount and the gas exhaust amount are balanced, and the inside of the plastic bottle B is set to a predetermined gas pressure.
[0138]
Next, high frequency power having a frequency of 13.56 MHz, for example, is supplied from the high frequency power supply 96 to the cylindrical body 85 through the cable 97, the matching unit 99 and the power supply terminal 98. At this time, plasma is generated in the space in the plastic bottle B. Due to the generation of such plasma, the medium gas is dissociated by the plasma and the inner surface of the plastic bottle B stored in the storage member 84 is coated with a carbon film.
[0139]
After the thickness of the carbon film reaches a predetermined thickness, the supply of the high frequency power from the high frequency power supply 96 is stopped, the supply of the medium gas is stopped, the residual gas is exhausted, and the exhaust of the gas is stopped. , Nitrogen, rare gas, air, or the like is supplied into the plastic bottle B through the tubular space between the inner tube 102 and the outer tube 103 of the gas supply mechanism 101, and the inside and outside of the plastic bottle B are returned to atmospheric pressure, Remove the carbon film-coated PET bottle. Thereafter, the plastic bottle B is exchanged according to the above-described order, and the next plastic bottle coating operation is started.
[0140]
The medium gas is basically hydrocarbon, for example, alkanes such as methane, ethane, propane, butane, pentane and hexane; alkenes such as ethylene, propylene, butene, pentene and butadiene; alkynes such as acetylene; benzene Aromatic hydrocarbons such as toluene, xylene, indene, naphthalene and phenanthrene; cycloparaffins such as cyclopropane and cyclohexane; cycloolefins such as cyclopentene and cyclohexene; oxygen-containing hydrocarbons such as methyl alcohol and ethyl alcohol; Nitrogen-containing hydrocarbons such as methylamine, ethylamine and aniline can be used, and other carbon monoxide and carbon dioxide can also be used.
[0141]
The high frequency power is generally 13.56 MHz and 100 to 1000 W, but is not limited thereto. Further, the bias power may be applied continuously or intermittently (pulsed).
[0142]
  more than,Of the present inventionAccording to the embodiment, the medium gas is supplied through the tubular space between the inner tube 102 and the outer tube 103 of the gas supply mechanism 101, and the spiral slit formed in the outer tube 103 portion located at the mouth of the plastic bottle B As shown in FIG. 7 described above, the air is blown out from the bottle 104 into the plastic bottle B, and the lower end of the inner tube 102 projects downward from the lower end of the outer tube 103 to exhaust the gas in the plastic bottle B through the inner tube 102. Further, the swirl flow 105 of the medium gas can be lowered from the mouth portion of the PET bottle B toward the inside, and thereafter, the medium gas flow can be generated to be raised by the exhaust action by the inner tube 102. For this reason, it is possible to forcibly make a gas flow from the bottom of the plastic bottle B toward the mouth, and to prevent a medium gas from being retained in the plastic bottle B. As a result, when plasma is generated, the plasma can be exposed to a medium gas extending from the vicinity of the bottom of the PET bottle B to the mouth for an equal period of time, and generation of powdery substances can be prevented. It is possible to coat a carbon film having a uniform film thickness with no mixing of the powdery substance and good film quality.
[0143]
Therefore, the inner surface carbon film-coated PET bottle having excellent barrier properties that prevents the permeation of oxygen from the outside and the permeation of carbon dioxide from the inside (for example, carbonated drinking water) can be mass-produced.
[0144]
Further, by inserting and fixing a cylindrical spacer 87 made of a dielectric material having a hollow portion 86 on the upper portion of the cylindrical body 85, only the inner surface on the bottom side from the shoulder portion of the plastic bottle B in the generation of the plasma. In addition, a carbon film having a uniform thickness can be coated on the inner surface of the shoulder from the mouth of the plastic bottle B facing the spacer 49 made of the dielectric material.
[0145]
  In addition,Of the present inventionIn the embodiment, the following other forms can be adopted.
[0146]
(1) A cylindrical body 85 as a storage member, a columnar spacer 87 inserted and fixed in an upper portion of the cylindrical body 85, and a disc-shaped bottom plate 88 disposed at the bottom of the cylindrical body 85. Although comprised, you may comprise by the cylindrical body in which the said cylindrical spacer part was integrated, and the disk shaped bottom plate arrange | positioned at the bottom part of this cylindrical body.
[0147]
  (2) The plasma generation mechanism is described above.FruitFor example, a cavity resonator or an inductively coupled plasma apparatus using a microwave may be used.
[0148]
  (3) The plasma generation mechanism is described above.FruitNot limited to the configuration described in the embodiment, the first to fourthExamination exampleThe plasma apparatus may be used.
[0149]
  The firstExamination exampleTo the second4 study examples and the present inventionIn the embodiment, an example of the carbon film has been shown. However, other barrier films, for example, a SiOx film using a mixed gas of an organic silicon compound such as TEOS (tetraethoxysilane) and oxygen gas as a raw material, a metal such as Al, etc. This method can also be used for thin films and organic thin films.
[0150]
【The invention's effect】
As described above in detail, according to the present invention, a film forming apparatus for an inner surface of a plastic container, which has a good film quality without mixing powdery substances on the inner surface of the plastic container and can coat a film having a uniform thickness. Can be provided.
[0151]
Further, according to the present invention, there is provided a method capable of producing a plastic container having a good film quality free from mixing of powdery substances, a film having a uniform film thickness coated on the inner surface, and an excellent barrier property against oxygen and carbon dioxide. Can be provided.
[Brief description of the drawings]
FIG. 1 shows the present invention.The present inventor examined in relation toFirstExamination exampleSectional drawing which shows the carbon film formation apparatus to the inner surface of the plastic container which concerns on.
FIG. 2 is a cross-sectional view of the bottom (cap) of the internal electrode in FIG.
[Fig. 3]First study exampleSectional drawing for demonstrating the effect | action of the carbon film formation apparatus to the inner surface of the plastic container which concerns on.
FIG. 4 The present inventionThe present inventor examined in relation toSecondExamination exampleSectional drawing which shows the modification of the internal electrode integrated in the carbon film formation apparatus to the inner surface of the plastic container which concerns on this.
FIG. 5 shows the present invention.The present inventor examined in relation toThirdExamination exampleSectional drawing which shows the carbon film formation apparatus to the inner surface of the plastic container which concerns on.
FIG. 6The present inventor examined in relation to4thExamination exampleSectional drawing which shows the carbon film formation apparatus to the inner surface of the plastic container which concerns on.
FIG. 7The fruitSectional drawing which shows the carbon film formation apparatus to the inner surface of the plastic container which concerns on embodiment.
8 is a perspective view showing the gas supply mechanism of FIG.
[Explanation of symbols]
2, 42, 82 ... support member, 4, 44 ... external electrode body, 5, 45 ... external electrode bottom member, 6, 46 ... external electrode, 10, 52, 94 ... exhaust pipe, 13, 55 ... high frequency power source, 17 , 59, 107 ... gas supply pipes, 18, 60, 102 ... internal electrodes, 22, 112 ... gas blowing holes, 23, 105, 113 ... swirl flow 24, 65 ... power supply for bias, 33, 74 ... earth shield pipes, 34, 75 ... high-frequency power source, 49, 87 ... cylindrical spacer, 84 ... storage member, 85 ... cylindrical body, 101, 106 ... gas supply mechanism, 102 ... inner pipe, 103 ... outer pipe, 104 ... spiral Slit, 109 ... gas blowing member, B ... plastic bottle,

Claims (4)

An external electrode having a size surrounding the plastic container when the plastic container is processed;
A gas supply mechanism that is inserted into the plastic container in the external electrode through the insulating member on the end surface of the external electrode on the side where the mouth of the container is located , and is connected to the ground side to serve as the internal electrode ;
A high-frequency power source connected to the external electrode;
Comprising
The gas supply mechanism has a double tube structure including an inner tube and an outer tube, the inner tube is used for gas exhaust, and the medium gas is supplied between the inner tube and the outer tube. A device for forming a barrier film on the inner surface of a plastic container is characterized in that a spiral slit is formed in the outer tube portion located in the plastic container. In manufacturing an inner surface barrier film-coated plastic container using the barrier film forming apparatus according to claim 1,
(A) inserting a plastic container as an object to be processed into the external electrode;
(B) A gas supply mechanism having a double tube structure comprising an inner tube and an outer tube and having a spiral slit formed in the outer tube portion of the external electrode on the side where the mouth of the container is located Inserting into the inside of the plastic container through an insulating member on the end surface;
(C) After exhausting the gas inside and outside the container through the inner pipe of the gas supply mechanism, a medium gas is supplied between the inner pipe and the outer pipe of the gas supply mechanism, and the medium gas is supplied from the spiral slit of the outer pipe. Blowing out as a swirl flow into the plastic container to raise the inside of the plastic container, and setting the inside of the exhaust pipe including the plastic container to a predetermined gas pressure;
(D) supplying high frequency power from a high frequency power source to the external electrode, generating plasma in the plastic container, dissociating the medium gas by the plasma, and coating a barrier film on the inner surface of the plastic container. A method for producing an inner surface barrier film-coated plastic container.   The barrier film forming apparatus according to claim 1, wherein the barrier film is a carbon film.   3. The method for manufacturing an inner surface barrier film-coated plastic container according to claim 2, wherein the barrier film is a carbon film.

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