JP2007204774A - Vessel treatment device using plasma - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vessel treatment device using plasma where microwave plasma CVD (chemical vapor deposition) coating is applied to the surface of a three-dimensional hollow vessel such as a plastic bottole and a paper vessel using plastics and paper as raw materials. <P>SOLUTION: The vessel treatment device using plasma, has a metal hollow enclosure (2) for applying one or more plasma treatment to the conductor face of a waveguide (1) for feeding microwaves, wherein the side face is electrically joined, and the electromagnetic field energies of the metal hollow enclosure (2) and the waveguide (1) are bonded through a slit (3) bored in respective joined faces. The vessel treatment device using plasma is characterized in that the slit part bored in the joined faces is provided with a space part (4) for controlling the bond of the microwaves. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a container processing apparatus using plasma for performing microwave plasma CVD coating on the surface of a three-dimensional hollow container such as a plastic bottle or paper container made of plastic or paper.

  Three-dimensional hollow containers represented by glass, metal, paper, and plastic containers are generally used in various fields such as food and medicine. In particular, plastic containers are widely used taking advantage of light weight and low cost.

  Various functions are required for a three-dimensional hollow container, but a plastic container is required to have a barrier property against carbon dioxide and oxygen from the viewpoint of protecting contents.

  For this reason, a technique for coating a plastic container with a predetermined substance has been developed. (For example, refer to Patent Document 1).

  In these technologies, a thin film is formed using plasma generated by microwave energy input into a metal hollow body by placing a plastic or other three-dimensional container into which the process gas is injected inside the metal hollow body. It is.

Prior art documents are shown below.
Special table 2002-509845 gazette

  However, when forming a thin film using the above plasma, it is important to generate plasma by efficiently supplying microwave energy to the plasma container processing apparatus. Furthermore, there is a problem that the container processing apparatus using plasma is expensive.

  In order to reduce costs and the like, there is a method in which microwave energy is divided by waveguide branching from a single power source into a plurality of film forming tanks.

  However, when branching a waveguide, a waveguide branch member must be used, and a space is also required. And there exists a problem that this apparatus enlarges.

  For this purpose, there is a method in which microwaves are coupled by bonding a metal film housing for film formation to a waveguide that supplies microwaves, and by forming a slit in the bonded portion.

  However, in this method, the joint between the waveguide and the metal hollow casing for film formation is weak. In addition, there is a problem that it is difficult to input sufficient electric power for performing the plasma treatment into the metal hollow housing.

  The present invention is intended to solve such problems of the prior art, and microwave energy can be supplied by a slit formed in the waveguide without using a waveguide branching member. And it aims at providing the container processing apparatus using the plasma which can distribute a microwave energy to several metal hollow housing | casing for film-forming without being large in size cheaply.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 of the present invention provides at least one conductor surface of the waveguide (1) for supplying microwaves. The metal hollow casing (2) for performing the plasma treatment of the metal hollow casing (2), the side surfaces thereof are electrically bonded, and the metal hollow casing (2) and the waveguide are guided by the slits (3) formed in the respective bonding surfaces. A container processing apparatus using plasma in which electromagnetic energy of the tube (1) is coupled, and a slit (4) provided in the joint surface is provided with a space (4) for adjusting the coupling of microwaves. This is a container processing apparatus that uses plasma.

  The invention according to claim 2 of the present invention is such that the size of the space (4) is such that λ is a micro wavelength in the axial direction connecting the metal hollow casing (2) and the waveguide (1). Further, the container processing apparatus using plasma according to claim 1, wherein X = 1 / 4λ + 10 mm or less and Y = 1 / 4λ ± 10 mm in the height direction. .

  The invention according to claim 3 of the present invention is the container using plasma according to claim 1 or 2, characterized in that a dielectric (5) that transmits microwaves is disposed inside the space (4). It is a processing device.

  The invention according to claim 4 of the present invention is arranged in such a manner that the process gas introduction pipe (6) made of a conductive material is electrically connected on the central axis of the inner cylindrical space of the metal hollow casing (2). The slot is arranged in a direction orthogonal to the central axis of the inner cylindrical space in order to excite the semi-coaxial mode (TEM mode) in the gas introduction pipe (6). A container processing apparatus using the plasma according to Item 1.

  The invention according to claim 5 of the present invention is such that when the metal hollow housing (2) is in the tube direction of the waveguide (1), λ is the wavelength of the microwave, and n is an integer equal to or greater than 1, 5. The container processing apparatus using plasma according to claim 1, wherein the container processing apparatus is arranged at intervals of 2λ × n ± 10 mm.

  The invention according to claim 6 of the present invention is characterized in that the metal hollow housing (2) is arranged so as to be symmetric with respect to the waveguide axis. A container processing apparatus using plasma.

  In the invention according to claim 7 of the present invention, the metal hollow casing (2) is symmetrical to the tube of the waveguide (1) and in the tube direction of the waveguide (1), λ is the wavelength of the microwave, and n is 7. The container processing apparatus using plasma according to claim 1, wherein the container processing apparatus is arranged with an interval of ½λ × n ± 10 mm when the integer is 1 or more.

  The container processing apparatus using plasma of the present invention uses a waveguide branching member or the like in order to supply microwave energy through a slit formed in the waveguide. For this reason, the apparatus can distribute microwave energy to a plurality of metal film forming housings without increasing the size.

  Moreover, the installation space of the container processing apparatus using the plasma of the present invention does not have to be wide because no waveguide branching member or the like is used. And total cost can be reduced.

A container processing apparatus using plasma according to the present invention will be described in detail below in accordance with an embodiment with reference to the drawings.

  FIG. 1 is a schematic view showing a schematic front view of an embodiment of a container processing apparatus using plasma of the present invention. FIG. 2 is a schematic view showing an outline of the plane of FIG. Further, FIG. 3 is a cross-sectional view showing a cross section taken along the line AA 'of FIG.

  FIG. 4 is a schematic view showing a schematic plan view of another embodiment of the container processing apparatus using the plasma of the present invention.

  The container processing apparatus using the plasma of the present invention comprises a metal hollow casing (2), a waveguide (1), a microwave power source (12) and the like as shown in FIGS. In addition, a space (4) is formed in the joint between the metal hollow housing (2) and the waveguide (1).

  A slit (3) is formed so that the cavity-side slit (7) faces the metal hollow casing (2) in the space and the waveguide-side slit (8) faces the waveguide (1). .

  In addition, microwave energy is coupled by a slit (3) drilled in the joint surface between the metal hollow casing (2) and the waveguide (1). When a long and narrow waveguide-side slit (8) is formed in the waveguide (1), the frequency at which the microwave leaks best differs depending on the length of the slit (8).

  In general, it is known that when a slit having a length of 1 / 2λ (microwave wavelength) of a frequency to be resonated is opened, microwave leakage from the slot becomes the largest.

  Moreover, in the container processing apparatus using plasma of the present invention, the length of the cavity-side slit (7) whose end face is cut because the inside of the metal hollow casing (2) for performing plasma processing is cylindrical. Draw an arc. And it becomes long compared with the waveguide side.

  For this purpose, a space (4) for adjusting impedance matching between the waveguide (1) and the metal hollow casing (2) is provided. And since it divides | segments into the cavity side slit (7) and the waveguide side slit (8) by the space part (4), it becomes possible to adjust each slit size.

  The space (4) can have various shapes such as a rectangle and a circle. For example, when the cross-sectional shape is rectangular, the axial direction connecting the hollow housing (2) and the waveguide (1) so that the waveguide side slit (7) and the cavity side slit (8) are best coupled. The value of X = 1 / 4λ + 10 mm or less where the reflection of the microwave is small is set to a value in the range of Y = 1 / 4λ ± 10 mm in the height direction.

  Next, as shown in FIG. 4, when a plurality of metal hollow casings (2) are joined to the waveguide (1), the waveguide side slit ( It is also possible to adjust the microwave coupling balance of the metal hollow casing (2) by changing the size of 8).

  The metal hollow casing (2) at this time is arranged symmetrically with respect to the waveguide axis direction or within a range of 1 / 2λ × n (an integer of 1 or more) ± 10 mm.

Furthermore, the inside of the metal hollow housing (2) needs to be in a low pressure state in order to generate plasma. A method of placing a cylindrical processing chamber (13) using a microwave transmitting material inside the metal hollow housing (2) and evacuating the inside of the chamber can also be used. (4) It is also possible to dispose a dielectric (5) or the like that transmits microwaves.

  The dielectric (5) is preferably made of a material such as quartz glass or fluororesin having a small dielectric loss in order to suppress heat generation.

  Next, the container which performs plasma processing with the container processing apparatus using the plasma of the present invention is a three-dimensional hollow container such as plastic. Here, a thin film is formed on the inner surface of the container by plasma chemical vapor deposition (PECVD method) for a PET bottle container (10) having a capacity of 500 ml and an average thickness of 0.5 mm made of polyester material such as polyethylene terephthalate. One example is shown below.

  As shown in FIGS. 1 to 3, the metal hollow casing (2) has a process gas introduction pipe (6) made of a conductive material on the central axis of the inner cylindrical space, and the metal hollow casing (2) metal mesh. Electrically connected through (11).

  The inner diameter of the cylindrical space inside the metal hollow housing (2) is 120 mm or less which does not generate a coaxial higher-order mode, and 90 to 110 mm that can easily take in and out a PET bottle or the like (10) as a coating target container. The range of is preferable.

  And similarly about the height of cylindrical space, the range of 150-250 mm sufficient for putting a container is preferable.

  The length of the gas introduction tube (6) is such that the gap between the bottom of the container and the tip of the gas introduction tube (6) is 5 so that the process gas is uniformly supplied to the inside of the PET bottle or the like (10). A value in the range of ˜30 mm is desirable.

  When the plasma treatment is performed, the gas is discharged from the hole of the metal mesh (11) that fixes the gas introduction pipe (6), so that the inside of the metal hollow housing (2) is optimally decompressed for plasma generation. Keep the environment.

  In addition, as a source gas for forming a thin film, hexamethyl disiloxane (hereinafter referred to as HMDSO) or tetramethyl disiloxane can be used as a main gas. Are used.

  These source gases are supplied into the PET bottle (10), which is a container to be coated, from holes formed in the side surface and the top surface of the gas introduction pipe (6).

  The thin film formed using the above-mentioned gas has a so-called ceramic layer SiOxCy (x = 1 to 2.2 / y = 0.3 to 3) as a main component.

  Next, the film forming process of the container processing apparatus using the plasma of the present invention will be described below. First, a PET bottle or the like (10) for forming a thin film is set inside the processing chamber (13) inside the metal hollow casing (2) of the container processing apparatus using the plasma of the present invention.

  Then, although not shown in the drawing, the inside of the metal hollow housing (2) is sucked up to 1.333 Pa (Pascal) by a vacuum device to maintain a reduced pressure environment.

Next, a raw material gas HMDSO for performing barrier thin film coating on the inner surface of the PET bottle (10) is injected at a flow rate of 10 ml / min and an oxygen flow rate of 50 ml / min, and the degree of vacuum in the PET bottle container etc. Is adjusted to a vacuum pressure of 13.33 Pa. And in this state,
A microwave power source (12) supplies microwave energy for about 5 seconds.

  At this time, the frequency of the microwave supplied from the power supply is set to a value of 2.45 GHz and power of 200 to 400 W. The microwave energy input to the waveguide (1) generates plasma in the raw material gas supplied into the metal hollow casing (2) through the slit (3) to form a thin film.

  Examples of the present invention will be specifically described below, but the present invention is not limited thereto.

<Example 1>
The container processing apparatus using the plasma of the present invention shown in FIGS. 1 to 4 was carried out under the following conditions.

(1) .... No space (4) is provided. (2) ... The width of the slit (3) is 61 mm.
(3) ... Only one metal hollow casing (2) is connected. (4) ... The frequency of the microwave power supply is 2.45 GHz.
(5) ... Input power is 350W
(6) ... There is a processing chamber (13) A thin film was formed on the inner surface of a 500 ml PET bottle (10) under the above conditions.

<Example 2>
(1) .... Space part (4) X = 30mm Y = 30mm
(2) ... The width of the slit (3) is 58mm
(3) ... Only one metal hollow casing (2) is connected. (4) ... The frequency of the microwave power supply is 2.45 GHz.
(5) ... Input power is 350W
(6) ... There is a processing chamber (13) A thin film was formed on the inner surface of a 500 ml PET bottle (10) under the above conditions.

<Example 3>
(1) ... ・ Space part (4) is X = 12mm Y = 30mm
(2) ... The width of the slit (3) is 58mm
(3) ················· Two metal hollow casings (2) are provided and connected to the waveguide axis. (4) ··· The frequency of the microwave power source is 2.45 GHz.
(5) ... Input power is 350W
(6): No processing chamber (13) (7): Dielectric (5) is quartz glass A thin film was formed on the inner surface of a 500 ml PET bottle (10) under the above conditions.

<Evaluation>
The oxygen barrier values of the PET bottles (10) obtained in Examples 1 to 3 were measured and evaluated (◯: pass, x: fail). The results are shown in Table 1.

表１は、ＰＥＴボトル（１０）の酸素バリア値、評価の結果を記す。

Table 1 shows the oxygen barrier value of PET bottle (10) and the results of evaluation.

<Evaluation results>
The oxygen barrier value in the case where the space (4) of Example 1 is not provided is 11.1 (fmol)
/ M ² / s / pa), the oxygen barrier value of Example 2 in which the space (4) is provided is 0.96 (fmol / m ² / s / pa), and Example 3 is an oxygen barrier. The value was 1.11 (fmol / m ² / s / pa) and all passed.

  The container processing apparatus using the plasma of the present invention is excellent as a container processing apparatus capable of coating microwave plasma CVD on the surface of a three-dimensional hollow container such as a plastic bottle or a paper container without thermal deformation. It is a wonderful invention that can be used in a wide range of fields, such as precision parts in the precision field or medical parts in the medical field.

It is the schematic which shows the outline of the front of one Example of the container processing apparatus using the plasma of this invention. It is the schematic which shows the outline of the plane of FIG. It is sectional drawing which shows the AA line cross section of FIG. It is the schematic which shows the outline of the plane of other one Example of the container processing apparatus using the plasma of this invention.

Explanation of symbols

(1) Waveguide (2) Metal hollow casing (3) Slit (4) Space (5) Dielectric (6) Gas inlet pipe (7) Cavity side slit (8) Waveguide side slit (9) Power feed Point (10) PET bottles (other plastic hollow containers)
(11) Metal mesh (12) Microwave power supply (13) Processing chamber

Claims (7)

  One or more metal hollow casings (2) for performing plasma treatment are provided on a conductor surface of a waveguide (1) for supplying a microwave, and the side surfaces thereof are electrically bonded, and each bonding is performed. A container processing apparatus using plasma in which electromagnetic energy of a metal hollow housing (2) and a waveguide (1) is coupled by a slit (3) vacated on a surface, which is formed in the joint surface. A vessel processing apparatus using plasma, characterized in that a space (4) for adjusting the coupling of microwaves is provided in the slit portion.   When the size of the space (4) is in the axial direction connecting the metal hollow casing (2) and the waveguide (1) and λ is a micro wavelength, X = 1 / 4λ + 10 mm or less. 2. The vessel processing apparatus using plasma according to claim 1, wherein the value in the height direction is Y = 1 / 4λ ± 10 mm.   The container processing apparatus using plasma according to claim 1 or 2, wherein a dielectric (5) that transmits microwaves is disposed in the space (4).   A process gas introduction pipe (6) made of a conductive material is disposed on the central axis of the inner cylindrical space of the metal hollow casing (2) in an electrically connected state, and is semi-coaxial with the gas introduction pipe (6). 4. A vessel processing apparatus using plasma according to claim 1, wherein slots are arranged in a direction orthogonal to the central axis of the inner cylindrical space in order to excite the mode (TEM mode). .   Metal hollow casings (2) are arranged at intervals of 1 / 2λ × n ± 10 mm in the tube direction of the waveguide (1), where λ is the wavelength of the microwave and n is an integer equal to or greater than 1. The container processing apparatus using the plasma according to claim 1, wherein the apparatus is a plasma processing apparatus.   The container processing apparatus using plasma according to any one of claims 1 to 5, wherein the metal hollow casing (2) is arranged so as to be symmetric with respect to the waveguide axis.   When the metal hollow housing (2) is symmetrical to the tube of the waveguide (1) and in the tube direction of the waveguide (1), λ is the wavelength of the microwave and n is an integer of 1 or more. The container processing apparatus using plasma according to claim 1, wherein the container processing apparatus is arranged at intervals of 2λ × n ± 10 mm.

Images