JP2007204773A - Vessel treatment device using plasma - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vessel treatment device using plasma for performing microwave plasma CVD (chemical vapor deposition) coating onto the surface of a three-dimensional hollow vessel such as a plastic bottle and a paper vessel using plastics and paper as raw materials. <P>SOLUTION: The vessel treatment device using plasma in which the side face of a metal hollow enclosure (1) for performing plasma treatment is joined to a conductor face of a waveguide (2) for feeding microwaves is characterized in that the electromagnetic field energies of the metal hollow enclosure (1) and the waveguide (2) are bonded through at least two or more slits formed so as to be bored in the joining face. <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 (see, for example, 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.

  When microwave energy is supplied so as to pass through the container to be coated, the container to be coated becomes a dielectric, which causes reflection or loss of the microwave energy.

  In particular, when the microwave energy is concentrated on a part of the container to be coated, not only will the coating film quality vary, but also problems such as deformation of the container due to heat generation will occur.

  In order to solve this problem, when a microwave is distributed using a T-branch waveguide or the like, a problem arises in that the apparatus becomes large because a space for the branching waveguide is required.

  The present invention is intended to solve such problems of the prior art, and the microwave energy input to the microwave supply waveguide is perforated at the joint surface between the metal cavity housing and the waveguide. A container processing device using plasma that can distribute and supply microwave energy through a plurality of slits, thereby preventing unevenness and concentration of microwave energy and suppressing variations in the thickness of the coating layer and deformation of the container due to heat generation. The purpose is to provide.

The present invention has been made to solve the above problems, and the invention according to claim 1 of the present invention supplies microwaves to the side surface of the metal hollow housing (1) for performing plasma processing. A container processing apparatus using plasma in which the conductor surfaces of the waveguide (2) are bonded to each other, wherein the metal hollow casing (1) is formed by at least two slits formed in the bonding surface. Is a container processing apparatus using plasma characterized in that the electromagnetic field energy of the waveguide (2) is coupled.
According to the second aspect of the present invention, the tube axis direction of the waveguide (2) and the central axis of the gas introduction tube (3) are orthogonal to each other, and the long side of the waveguide (2) is a metal hollow housing. When joining with (1), the distance between the feeding point (7) of the microwave power source (8) and the slot center point is when λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm. 2. The vessel processing apparatus using plasma according to claim 1, wherein the position is 1 / 2λ × n + α.

  In the invention according to claim 3 of the present invention, the tube axis direction of the waveguide (2) and the central axis of the gas introduction tube (3) are parallel to each other, and the long side of the waveguide (2) is a metal hollow housing ( 1), the distance from the feed point (7) of the microwave power source (8) to the slot center point is as follows: λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm. (2n-1) It is a position of (lambda) / 4 + (alpha), The container processing apparatus using the plasma of Claim 1 or 2 characterized by the above-mentioned.

  In the invention according to claim 4 of the present invention, the interval between the slits adjacent to the center point of the slit disposed in the metal hollow casing (1) is λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm. The container processing apparatus using plasma according to any one of claims 1 to 3, wherein the container processing apparatus is arranged at 1 / 2λ × n + α.

  The invention according to claim 5 of the present invention is arranged in such a manner that the process gas introduction pipe (3) made of a conductive material is electrically connected on the central axis of the inner cylindrical space of the metal hollow casing (1). The slits are arranged so as to be 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 (3). It is a container processing apparatus using the described plasma.

  The container processing apparatus using the plasma of the present invention distributes and supplies the microwave energy through the slits, thereby preventing the deviation and concentration of the microwave energy and suppressing the variation in the thickness of the coating layer and the deformation of the container due to heat generation.

  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 front view showing an outline of a partial cross section of an embodiment of a container processing apparatus using plasma of the present invention. FIG. 2 is a schematic plan view showing an outline of the plane of FIG.

  FIG. 3 is a schematic front view showing the outline of a partial cross section of another embodiment of the container processing apparatus using the plasma of the present invention. FIG. 4 is a schematic plan view showing an outline of the plane of FIG.

  The container processing apparatus using the plasma of the present invention comprises a metal hollow casing (1), a waveguide (2), a microwave power source (8) and the like as shown in FIGS. Then, at least two or more slits (4) are formed in the joint surface between the metal hollow casing (1) and the waveguide (2).

Moreover, the container which plasma-processes with the container processing apparatus using the plasma of this invention targets three-dimensional hollow containers, such as a plastics. Here, a thin film is formed on the inner surface of the container by plasma chemical vapor deposition (PECVD) for a PET bottle container (5) having a capacity of 500 ml and an average wall thickness of 0.5 mm made of a polyester material such as polyethylene terephthalate. However, the present invention is not limited to these examples.

  1-4, a process gas introduction pipe (3) made of a conductive material is provided through a metal mesh (9) on the central axis of the inner cylindrical space of the metal hollow casing (1). . And it is electrically connected.

  Further, the inner diameter of the cylindrical space inside the metal hollow housing (1) is 120 mm or less which does not generate the coaxial higher-order mode, and the PET bottle or the like (5) which is the container to be coated can be easily taken in and out 90- A range of 110 mm is preferred.

  Similarly, the height of the cylindrical space is preferably in the range of about 150 to 250 mm, which is sufficient for the container.

  The length of the gas introduction pipe (3) is such that the gap between the bottom of the container and the tip of the gas introduction pipe (3) is 5 to 30 mm so that the process gas is uniformly supplied into the PET bottle or the like (5). A range value is desirable.

  Then, in order to keep the container to be coated in a reduced pressure environment capable of plasma processing, a plasma processing chamber made of a dielectric material capable of transmitting microwaves such as fluororesin and quartz glass so as to surround the periphery of the container ( 6) is provided inside the metal hollow housing (1).

  Further, when performing plasma processing, the inside of the processing chamber (6) has a reduced pressure environment optimal for plasma generation by discharging gas from the hole of the metal mesh (9) fixing the gas introduction pipe (3). To be kept.

  Next, the positional relationship when the metal hollow casing (1) side surface and the waveguide (2) long side conductor surface are joined will be described. There are the following two combinations of the portion where the central axis of the gas introduction tube (3) and the slit (4) in the tube axis direction of the waveguide (2) are formed.

  (1) When joined so that the axial directions thereof are orthogonal to each other (shown in FIGS. 1 and 2).

  (2) When joined so that their axial directions are parallel to each other (shown in FIGS. 3 and 4).

  As shown in FIG. 1 and FIG. 2, when joining is performed so that the axial directions are orthogonal, the distance between the microwave feeding point (7) and the center point of the slit (4) is λ is the wavelength of the microwave, and n is 1 or more. It is desirable that the position be 1 / 2λ × n + α where α is ± 10 mm. Then, the microwave is radiated most efficiently into the metal hollow housing (1) at the above position.

  3 and FIG. 4, when joining so that the axial directions are parallel, the distance between the microwave feeding point (7) and the center point of the slit (4) is λ, the wavelength of the microwave, n It is desirable that the position is (2n−1) λ / 4 + α where is an integer of 1 or more and α is ± 10 mm. Then, the microwave is radiated most efficiently into the metal hollow housing (1) at the above position.

  In addition, a slit (4) drilled in the joint between the metal hollow casing (1) and the waveguide (2) is an internal cylinder for exciting the semi-coaxial mode (TEM mode) in the gas introduction pipe (3). It arrange | positions so that it may orthogonally cross on a space center axis | shaft.

  At this time, the length and the gap of the slit (4) are preferably within a range of ± 30 mm and a length of 2 to 15 mm around a length ½λ at which the slot resonates.

  The source gas for forming the thin film can be hexamethyldisiloxane (hereinafter referred to as HMDSO), tetramethyldisiloxane, or the like as the main gas. Further, oxygen, nitrogen or the like is used as the sub gas.

  These source gases are supplied into the PET bottle (3), which is a container to be coated, from holes formed in the side surface and the top surface of the gas introduction pipe (3). And the thin film formed using the said gas has what is called ceramic layer SiOxCy (x = 1-2.2 / y = 0.3-3) 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 (5) is set inside the processing chamber (6) in the metal hollow casing (1) of the container processing apparatus using the plasma of the present invention. Then, although not shown in the drawing, the inside of the processing chamber (6) is sucked with a vacuum device up to 1.333 Pa (Pascal) to maintain a reduced pressure environment.

  Next, a raw material gas HMDSO for barrier film coating on the inner surface of the PET bottle or the like (5) is injected at a flow rate of 10 ml / min and an oxygen flow rate of 50 ml / min to vacuum the PET bottle or the like (5). The degree is adjusted to a vacuum pressure of 13.33 Pa. In this state, microwave energy is supplied from the microwave power source (8) 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 (2) is supplied to the inside of the metal hollow casing (1) through the slit (4), and plasma is generated in the source gas inside the chamber (6) to form a thin film.

Under the above conditions, the PET bottle or the like (5) in which a thin film was formed on the inner surface of the PET bottle or the like (5) by the PCDV method showed no thermal deformation of the container due to the microwave. And the oxygen barrier value showed 0.92-1.29 (fmol / m < ² > / s / pa).

  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 front schematic which shows the outline of the partial cross section of one Example of the container processing apparatus using the plasma of this invention. FIG. 2 is a schematic plan view showing an outline of the plane of FIG. 1. It is the front schematic which shows the outline of the partial cross section of other one Example of the container processing apparatus using the plasma of this invention. FIG. 4 is a schematic plan view showing a schematic plan view of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Metal hollow housing 2 ... Waveguide 3 ... Gas introduction tube 4 ... Slit 5 ... PET bottle etc. 6 ... Processing chamber 7 ... Feeding point 8 ... Microwave power source 9 ... Metal mesh

Claims (5)

  A container processing apparatus using plasma in which a conductor surface of a waveguide (2) for supplying microwaves is bonded to a side surface of a metal hollow casing (1) for performing plasma processing, the bonding A container processing apparatus using plasma, wherein electromagnetic field energy of a metal hollow casing (1) and a waveguide (2) is coupled by at least two or more slits formed in the surface.   When the tube axis direction of the waveguide (2) and the central axis of the gas introduction tube (3) are orthogonal to each other and the long side of the waveguide (2) is joined to the metal hollow casing (1), a microwave power source The distance from the feed point (7) to the center point of the slot in (8) is a position of 1 / 2λ × n + α where λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm. The container processing apparatus using the plasma according to claim 1.   When the tube axis direction of the waveguide (2) and the central axis of the gas introduction tube (3) are parallel to each other and the long side of the waveguide (2) is joined to the metal cavity housing (1), a microwave power source The distance from the feeding point (7) of (8) to the center point of the slot is the position of (2n-1) λ / 4 + α where λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm. The container processing apparatus using plasma according to claim 1 or 2, wherein   When the distance between the slit adjacent to the center point of the slit disposed in the metal hollow housing (1) is λ is the wavelength of the microwave, n is an integer of 1 or more, and α is ± 10 mm, 1 / 2λ × n + α The container processing apparatus using plasma according to any one of claims 1 to 3, wherein the container processing apparatus is disposed in the container.   A process gas introduction pipe (3) made of a conductive material is disposed on the central axis of the inner cylindrical space of the metal hollow casing (1) in an electrically connected state, and is semi-coaxial with the gas introduction pipe (3). The container processing apparatus using plasma according to any one of claims 1 to 4, wherein a slit is disposed so as to be orthogonal to the central axis of the inner cylindrical space in order to excite the mode (TEM mode).

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