JP4544552B2 - Barrier film production method and barrier film substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for producing a barrier film in which a barrier layer is formed on a plastic substrate using a plasma CVD method (chemical vapor deposition method).
[0002]
[Prior art]
As a barrier film used for food packaging, etc., it is made of silicon oxide or the like using a plasma CVD (chemical vapor deposition) method on the surface of a plastic substrate such as a polyester resin film or a polyamide resin film. Some have formed a barrier layer.
[0003]
As a method of manufacturing this type of barrier film, a base material is wound around a drum provided in a vacuum chamber, the base material is run by rotating the drum, and a source gas is supplied near the outer periphery of the drum. However, a method is known in which a plasma discharge is generated in the vicinity of the outer periphery of the drum with the drum as one electrode, and thereby a barrier layer is continuously formed on the surface of the running substrate (for example, Japanese Patent Laid-Open No. 8- 142252).
[0004]
[Problems to be solved by the invention]
According to the manufacturing method described above, since the film formation can be performed continuously, the barrier film can be manufactured efficiently and at low cost. However, there are cases in which a phenomenon affecting the quality of the film occurs, for example, wrinkles occur in the film during the manufacturing process and the plasma becomes unstable.
[0005]
An object of the present invention is to improve the stability of quality when a barrier layer is formed using plasma CVD while running a substrate.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the inventors have made various studies and, as a result, have obtained the following knowledge. When a film is formed on the surface of the base material by plasma CVD while the drum and the base material are in close contact with each other, the base material is heated by the heat of the plasma generation region, and a gas such as water vapor is released from the base material. Since the base material and the drum are in close contact with each other, when the gas is released from the contact surface side of the base material with respect to the drum, the base material expands and floats from the drum, resulting in wrinkles on the base material. Deposition quality deteriorates. In order to suppress the heating of the base material by the plasma, the drum is cooled to a room temperature or lower. However, when the base material is lifted from the drum, the cooling effect by the drum is also impaired, and the quality of the film is also impaired in this respect.
[0007]
Therefore, the inventors have studied various means for suppressing the lift of the film due to the gas released from the base material, and as a result, have completed the present invention.
[0008]
That is, in the present invention, a film-like base material (1) is wound around a drum (16) to travel the base material, and a plasma CVD method is used for the surface (1a) of the base material during the travel. In the method for producing a barrier film for forming the barrier layer (2), the film formation is performed in a state where an escape space for the gas released from the base material is provided in a portion where the base material and the drum face each other. The above-described problems are solved.
[0009]
According to this manufacturing method, the escape space for the gas released from the base material is secured, so that the base material is lifted from the drum and the quality of film formation and the like is maintained high. The escape place may be provided on the surface of the drum. As the escape place, the contact surface of the base material with respect to the drum may be processed into an uneven shape prior to film formation.
[0010]
In the present invention, the film-like base material (1) is wound around the drum (16) to travel the base material, and the barrier layer (using the plasma CVD method is applied to the surface of the base material during the travel). 2) In the barrier film manufacturing apparatus for forming a film, a escape space for the gas released from the substrate is provided in a portion where the substrate and the drum face each other. It can also be configured as a manufacturing apparatus.
[0011]
According to this manufacturing apparatus, for the same reason as the above manufacturing method, the base material is lifted from the drum, and the quality of film formation or the like is maintained high.
[0012]
In the manufacturing apparatus of the present invention, the escape place can be provided by winding a wire (30) around the surface of the drum. The escape material may be provided by winding a sheet material (31) having a gap around the surface of the drum. The sheet material (31) can be composed of paper or non-woven fabric. The sheet material may have conductivity. Furthermore, the escape area may be provided by performing uneven processing on the surface of the drum. Prior to film formation, the contact surface of the substrate with the drum may be processed into a concavo-convex shape to provide the escape area.
[0013]
Furthermore, the present invention is a substrate (1) for a barrier film in which a barrier layer (2) is formed on one side (1a) using a plasma CVD method, and is opposite to the surface on which the barrier layer is formed. It can also be configured as a base material of a barrier film characterized in that the surface (1b) is subjected to uneven processing.
[0014]
When this substrate is wound around a drum and the film is formed, the gas released from the substrate escapes into the recesses on the surface where the unevenness is processed. Is kept high.
[0015]
Furthermore, the barrier film according to the present invention is a barrier film (A) in which a barrier layer (2) is formed on one side (1a) using a plasma CVD method, and the surface on which the barrier layer is formed. An uneven surface is provided on the opposite surface. In this film, since the base material does not lift from the drum during the manufacturing process for the reasons described above, the barrier layer is formed with high quality and exhibits a highly reliable barrier effect.
[0016]
In the above, in order to facilitate the understanding of the invention of each claim, reference numerals in the attached drawings are added in parentheses, but the present invention is not limited to the illustrated embodiments.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Fig.1 (a) has shown an example of the barrier film which this invention makes object. The barrier film A has a configuration in which a barrier layer 2 is provided on one side 1 a of a plastic substrate 1. This barrier film A may be used as a packaging material in the state of FIG. 1A, but as shown in FIG. 1B, a laminate in which a resin layer 3 is further formed on the surface of the barrier layer 2 It may be used as a packaging material in the state of the material B.
[0018]
For the substrate 1, various flexible resin films such as a polyester resin and a polyamide resin can be used. Specific examples thereof include stretched or unstretched resin films such as polyester, nylon, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, cellulose, polyacrylate, polyurethane, cellophane, polyethylene terephthalate, and ionomer. Although the thickness of the base material 1 can be suitably set from the purpose of use of the barrier film, stability during production, and the like, it can be set to about 10 to 100 μm, for example.
[0019]
The barrier layer 2 is configured as a continuous layer mainly composed of silicon oxide, for example. The silicon oxide constituting the barrier layer 2 is a thin film of SiOx (X = 1 to 2), preferably a continuous layer, and has a thickness of about 10 to 3000 mm, preferably about 60 to 400 mm. In particular, from the viewpoint of transparency, the continuous layer of silicon oxide is preferably a thin film of SiOx (X = 1.7 to 2). In addition to silicon oxide, the barrier layer 2 may contain at least one compound composed of one or more elements of carbon, hydrogen, silicon and oxygen. For example, when a compound having a C—H bond, a compound having a Si—H bond, or a simple substance of carbon is in the form of graphite, diamond, or fullerene, and further containing a raw material organosilicon compound or a derivative thereof There is. Specific examples include hydrocarbon having a CH ₃ site, hydrosilica such as SiH ₃ silyl, SiH ₂ silylene, and hydroxyl derivatives such as SiH ₂ OH silanol. In addition to the above, the type, amount, etc. of the compound contained in the barrier layer can be changed by changing the conditions of the vapor deposition process.
[0020]
The resin layer 3 can be variously selected depending on the purpose of use of the film A. For example, polyethylene resin, polypropylene resin, polystyrene resin, polyester resin, polyamide resin, polycarbonate resin, acrylic resin, polyvinyl alcohol resin, ethylene / vinyl alcohol copolymer A resin layer such as a coalescence, a polybutylene terephthalate resin, a polyethylene terephthalate resin, or a polyacrylonitrile resin can be used. The resin layer 3 may be a single layer or may have a multilayer structure composed of two or more kinds of resins. The thickness of such a resin layer 3 can be about 10-1000 micrometers, for example.
[0021]
FIG. 2 shows an example of a plasma CVD apparatus for producing the barrier film A. In this plasma CVD apparatus 11, the substrate 1 is wound around an unwinding roll 13 disposed in the chamber 12. The base material 1 drawn out from the roll 13 is wound around the drum 16 through the auxiliary rolls 14A and 15A, and is further wound around the winding roll 17 through the auxiliary rolls 15B and 14B. The drum 16 and the take-up roll 17 are rotationally driven in the direction of the arrow in the drawing by a drive device (not shown), whereby the base material 1 passes from the unwind roll 13 through the drum 16 to the take-up roll 17 (for example, 100 m / min.).
[0022]
The drum 16 is connected to a power source 18 and the chamber 12 is grounded. Further, the drum 16 is cooled to a room temperature or lower (for example, −10 to 0 ° C.) by a cooling device (not shown). The cooling temperature of the drum 16 is set so that the temperature of the substrate 1 during film formation does not rise above its glass transition temperature. The surface of the drum 16 is formed smoothly by, for example, chrome plating.
[0023]
The chamber 12 is connected to a vacuum pump 19. During film formation, the inside of the chamber 12 is depressurized to a predetermined pressure by the vacuum pump 19. The pressure is set in a range where plasma can be generated, and is generally set in a range of 1.333322 to 13.3322 Pa (10 to 100 mmtorr), preferably 6.6661 Pa (50 mmtorr).
[0024]
Gas supply devices 20A and 20B and a raw material volatilization supply device 21 are provided outside the chamber 12, and oxygen gas and inert gas (for example, argon gas and helium gas) are supplied from the respective devices 20A and 20B to volatilize the raw material. A film forming monomer gas generated by volatilizing an organic silicon oxide serving as a raw material of the barrier layer 2 is supplied from the supply device 21. These gases are mixed at a predetermined ratio to form a film forming mixed gas, and the mixed gas is supplied from the nozzle 22 to the vicinity of the outer periphery of the drum 16. A magnet 23 for promoting the generation of plasma is installed outside the drum 16, and the nozzle 22 opens in a plasma generation region P sandwiched between the magnet 23 and the drum 16.
[0025]
According to such an apparatus 11, a mixed gas is supplied from the nozzle 22 while the substrate 1 is traveling from the unwinding roll 13 toward the winding roll 17 in a state where the chamber 12 is decompressed to a predetermined pressure by the vacuum pump 19. Then, plasma is generated in the plasma generation region P due to the potential difference between the drum 16 and the nozzle 22, and the barrier layer 2 is formed on the surface of the substrate 1 when it passes through the plasma generation region P.
[0026]
In the apparatus 11 as described above, the base material 1 may be heated by the heat generated in the plasma generation region P, and gas may be released between the base material 1 and the drum 16. For example, when a polyamide-based resin film is used as the base material 1, the film contains about 2 to 3% of water, and about 4% of the water when the film is heated. Water vapor is released. If this water vapor is not properly treated, the base material 1 is lifted from the drum 16, so that the base material 1 is wrinkled or the plasma becomes unstable, affecting the quality of the film after film formation. Sometimes.
[0027]
The lift of the base material 1 can be effectively suppressed by the embodiment shown in FIGS.
[0028]
FIG. 3 shows an embodiment in which a wire 30 is wound around the surface of the drum 16. When film formation is performed by winding the substrate 1 on the wire 30, a gap is generated between the surface of the drum 16 and the substrate 1, and the gas released from the substrate 1 can escape into the gap. it can. Therefore, the base material 1 does not lift from the wire 30 and the quality of film formation is stabilized. Although the wire 30 is exaggerated in FIG. 3, the wire diameter may be much smaller than the diameter of the drum 16. The wire diameter is preferably set in the range of 0.1 to 1.0 mm, more preferably in the range of 0.2 to 0.5 mm. The pitch PT of the wires 30 is set to be equal to the diameter of the wires 30, in other words, it is desirable to wind the wires 30 around the drum 16 without gaps, but the pitch PT may be set to about 1 mm at the maximum. Instead of the wire 30, various wires such as a resin thread may be used. Since the CVD apparatus 11 generates plasma using the drum 16 as an electrode, it is desirable that the wire has conductivity.
[0029]
FIG. 4 shows an embodiment in which the surface of the drum 16 is covered with a sheet material 31. The sheet material 31 is made of, for example, paper or nonwoven fabric. These materials are fibrous, and have sufficient voids on the surface and inside thereof to release gas such as water vapor released from the substrate 1. Accordingly, when film formation is performed by winding the base material 1 on the sheet material 31, the gas released from the base material 1 escapes into the sheet material 31, and the base material 1 is not lifted from the sheet material 31, and is formed. The film quality is stable. The paper used for the sheet material 31 is preferably a white board having a basis weight of 100 to 400 g / m ² , particularly a conductive white board, and the nonwoven is preferably a dry nonwoven, particularly a conductive nonwoven. Instead of non-woven fabric, folded fabric may be used. In the above CVD apparatus 11, since the plasma is generated using the drum 16 as an electrode, it is preferable to impart conductivity to the sheet material 31.
[0030]
In the embodiment of FIGS. 3 and 4, another member is added to the surface of the drum 16 to secure a gas escape area. However, the uneven portion 16a may be directly processed on the surface of the drum 16 as shown in FIG. . As shown in FIG. 6, the concavo-convex portion 16 a may be formed by repeatedly providing a plurality of recesses 16 b on the surface of the drum 16, or may be formed by forming a plurality of grooves in the axial direction or circumferential direction of the drum 16. The recess 16b can be provided in various shapes and arrangements as shown in FIGS. In the case of FIG. 6, the width 16 of the recess 16b is preferably 0.1 to 1 mm, the interval W2 is 0.1 to 1 mm, and the depth DP is preferably 0.01 to 0.5 mm. The concavo-convex portion 16a may be formed, for example, by subjecting the surface of the drum 16 to shot blasting.
[0031]
The escape place of the gas released from the substrate 1 can be provided not only in the drum 16 but also in the substrate 1. For example, as shown in FIG. 8, the gas released from the base material 1 can be obtained by subjecting the contact surface (non-deposition surface) 1 b of the base material 1 to the drum 16 to uneven processing such as embossing and mat processing. It can escape to the clearance gap of the surface of the base material 1 itself.
[0032]
The present invention is not limited to the embodiments described above, and can be implemented in various forms. The drum is not limited to a cylindrical one, and any drum can be used as long as it operates in a certain direction and conveys the film while the film is pressed.
[0033]
【The invention's effect】
As described above, according to the present invention, when the barrier layer is continuously formed by the plasma CVD method while the substrate is wound around the drum and conveyed, the gas released from the substrate to the drum side is reduced. Proper escape can prevent the substrate from lifting from the drum. Therefore, a high quality barrier layer can be formed continuously and stably.
[Brief description of the drawings]
FIG. 1 is a view showing an example of a barrier film to which the present invention is applied and a packaging material using the same.
2 is a diagram showing a configuration of a plasma CVD manufacturing apparatus for forming a barrier layer on the base material of FIG. 1;
FIG. 3 is a view showing an embodiment in which a wire is wound around a drum.
FIG. 4 is a diagram showing an embodiment in which a sheet material is wound around a drum.
FIG. 5 is a diagram showing an embodiment in which unevenness processing is performed on the surface of a drum.
6 is an enlarged view of the surface of the drum in FIG. 5, where (a) is a plan view and (b) is a cross-sectional view.
7 is a diagram showing an example in which the configuration and arrangement of the recesses in FIG. 6 are changed.
FIG. 8 is a view showing an embodiment in which unevenness processing is performed in advance on a base material of a barrier film.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material 1a Surface 1b where the barrier layer is formed Surface 2b opposite to the surface where the barrier layer is formed 2 Barrier layer 16 Drum 16a Concave portion 16b Concavity 30 Wire (wire)
31 Sheet material

Claims (2)

In the method for producing a barrier film in which a film-like substrate is wound around a drum and the substrate is run, and a barrier layer is formed on the surface of the running substrate using a plasma CVD method.
Prior to film formation, the contact surface of the base material with respect to the drum is processed into a concavo-convex shape, and the film formation is performed in a state where a escape space for gas released from the base material is provided. Method.   A barrier used for manufacturing a barrier film in which a film-like substrate is wound around a drum and the substrate is run, and a barrier layer is formed on the surface of the running substrate using a plasma CVD method. A base material for the adhesive film,
  A base material for a barrier film, wherein the contact surface of the base material with respect to the drum is processed into a concavo-convex shape.

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