JP2013237897A - Vacuum film deposition system, gas barrier film, and laminate with gas barrier property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a vacuum film deposition system capable of achieving improved transparency and increased barrier properties in a gas barrier film while securing a high deposition rate, by using a vacuum deposition method, and capable of preventing a film from being damaged due to bumping and splashing generated from a deposition material when high density plasma is used; a gas barrier film prepared using a vacuum film deposition system; and a laminate with gas barrier properties.SOLUTION: A vacuum film deposition system in which a thin film is formed on a base material by a vacuum deposition method includes a means capable of generating plasma to perform activated deposition, independently from an evaporation means evaporating a deposition material to a deposition space, and also includes a magnetic field distribution control device for controlling plasma flow so that the surface of the base material is not exposed to plasma.

Description

  The present invention relates to a vacuum film forming apparatus, a gas barrier film, and a gas barrier laminate.

  Conventionally, gas barrier films are mainly laminated with aluminum foil or those provided with a vinylidene chloride coating layer, but the former makes it difficult to use a metal detector, microwave heating is impossible, There are drawbacks such as lack of transparency and the generation of aluminum during incineration, and the latter have the disadvantages of generating dioxins during incineration.

  A transparent ceramic film as a gas barrier film which replaces them has been invented and marketed. Generally, in order to produce a transparent ceramic film used for a film for food packaging materials, aluminum oxide or silicon oxide is formed on a web-like synthetic resin film conveyed at a speed of several meters per second from the viewpoint of economic cost. It is preferable to use a vapor deposition technique for forming a film.

  When forming a gas barrier layer by vapor deposition techniques, the energy provided to evaporate the material is primarily derived from thermal energy, so this degree of heating is the temperature at which the material being vapor deposited is slightly above the melting point. However, once evaporated, the vapor deposition particles reach the object while losing energy due to collision / diffusion with other evaporated particles without being given any more energy.

  For this reason, it is difficult to obtain a dense film having a high gas barrier property although the film forming speed is high. As a means for solving this problem, there is a plasma support method using plasma for the purpose of stably imparting transparency and gas barrier properties while ensuring the film forming speed (Patent Document 1).

  However, in order to promote the reaction even in an environment where the evaporation rate is high, such as a large amount of evaporation at high speed, it is necessary to supply a high-density plasma with active species (radicals) of the same dimension as the evaporation rate in the vacuum As feasible processes that satisfy these requirements, arc plasma, microwave plasma, ECR plasma in which a magnetic field is resonated with a microwave, and helicon waves are used. It is limited to helicon wave plasma etc. (for example, patent document 2, patent document 3).

  In recent years, a method of vapor deposition while applying energy from these high-density plasmas to vapor deposition particles has been developed. In either process, oxygen or a gas containing oxygen is supplied to react in the plasma-irradiated space. Oxidation reaction by oxygen is promoted throughout the space inside the vapor deposition chamber.

  This reaction generally extends to the evaporation interface where the vapor deposition material is evaporated, so that an oxide film is formed at the evaporation interface, the evaporation rate is reduced, and it becomes unstable. By breaking through and evaporating the evaporated particles, the film is damaged and the product performance is remarkably impaired.

  Known documents are shown below.

Japanese Patent Laid-Open No. 4-165065 JP 2010-185124 A JP 2011-21214 A

  The present invention has been made in view of the above-mentioned circumstances, and is a technique for improving the transparency of a gas barrier film and imparting higher barrier properties while ensuring a high film formation rate by a vacuum deposition method. When using plasma, a vacuum film forming apparatus that can suppress damage to the film due to bumping or splash generated from the vapor deposition material, a gas barrier film manufactured using the vacuum film forming apparatus, and a gas barrier It is an object to provide a conductive laminate.

  The invention according to claim 1 of the present invention is a vacuum film forming apparatus for forming a thin film on a base material by a vacuum evaporation method, and plasma is generated separately from evaporation means for evaporating an evaporation material to an evaporation space. A vacuum film forming apparatus comprising a means for generating and activating vapor deposition, and a magnetic field distribution control device for controlling a plasma flow so that a surface of the substrate is not exposed to the plasma It is.

  The invention according to claim 2 of the present invention is characterized in that the substrate is a web-like film substrate, and includes a conveying means for conveying the film substrate by roll-to-roll, and a thin film is formed on the film substrate. The vacuum film forming apparatus according to claim 1, wherein:

  The invention according to claim 3 of the present invention is characterized in that the magnetic field distribution control device is covered with a heat insulating material in order to withstand temperature rise due to generation of the plasma and evaporation of the vapor deposition material. The vacuum film forming apparatus according to 1 or 2.

  The invention according to claim 4 of the present invention is the vacuum film forming apparatus according to any one of claims 1 to 3, wherein the vacuum vapor deposition method is a resistance heating vapor deposition method.

  The invention according to claim 5 of the present invention provides the resistance heating boat with a metal wire having the vapor deposition material or a partial composition of the vapor deposition material in the resistance heating vacuum deposition method. Item 5. The vacuum film forming apparatus according to Item 4.

  The invention according to claim 6 of the present invention is characterized in that the plasma generating means uses any one of hollow cathode discharge, microwave discharge, ICP discharge, and helicon wave discharge. 6. The vacuum film forming apparatus according to any one of 5 above.

  The invention according to claim 7 of the present invention is characterized in that the plasma generating means is hollow cathode discharge, and at least one anode with respect to the hollow cathode is in the vicinity of the vapor deposition material. A film forming apparatus.

Invention of Claim 8 of this invention is produced using the vacuum film-forming apparatus of any one of Claims 1-7, and water vapor permeability is 2 g / m < ² > / day or less. It is a gas barrier film characterized.

Invention of Claim 9 of this invention is produced using the vacuum film-forming apparatus of any one of Claims 1-7, and oxygen permeability is 3 cc / m < ² > / day or less. It is a gas barrier film characterized.

  An invention according to claim 10 of the present invention is a gas barrier laminate produced using the gas barrier film according to claim 8 or 9.

  According to the present invention, a vacuum film forming apparatus capable of improving the transparency of a gas barrier film and imparting higher barrier properties while ensuring a high film forming speed by a vacuum deposition method is obtained. In the gas barrier film produced using, bumping and splash are suppressed, and the film is not damaged. Therefore, the gas barrier laminate using this has high barrier properties.

It is the schematic diagram which showed one Embodiment of the vacuum film-forming apparatus of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of a vacuum film forming apparatus of the present invention.

  The vacuum film forming apparatus 30 according to the present embodiment includes a film forming chamber 10 and a take-up chamber 11, and includes a transport unit that transports the web-shaped film substrate 15 into the vacuum film forming apparatus 30 by roll-to-roll. It has. Means for transporting the film substrate 15 in a roll-to-roll manner includes an unwinding roller 12, a winding roller 13, and a main roller 14.

  The film substrate 15 is unwound from the unwinding roller 12 and is wound on the winding roller 13 via the main roller 14. At this time, the vapor deposition material 16 is deposited on the film substrate 15 by the main roller 14 to form a vapor deposition film.

  The film substrate 15 is not particularly limited, and a known one can be used. For example, polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polystyrene, ethylene-vinyl alcohol copolymer, polyvinyl chloride, polyimide , Polyvinyl alcohol, polycarbonate, polyether sulfone, acrylic resin, cellulose-based films (triacetyl cellulose, diacetyl cellulose, etc.), and the like. Further, the thickness of the base film 15 is not limited, and can be appropriately selected from about 6 μm to 200 μm depending on the application.

  Further, the vacuum film forming apparatus 30 of the present embodiment includes means for evaporating the vapor deposition material 16 in order to deposit the vapor deposition material 16 on the film substrate 15. The evaporation material 16 is supplied to the resistance heating crucible 17 and heated to evaporate the evaporation material 16. The resistance heating crucible 17 is connected to a resistance heating DC power source 20 for heating.

  The vapor deposition material 16 is not particularly limited, and a known material can be used. For example, any metal material such as aluminum (Al), tin (Sn), zinc (Zn), and indium (In) may be supplied in a wire shape.

  In addition, by depositing a reactive gas such as oxygen from the gas pipe 23, it is possible to perform reactive vapor deposition using a reaction such as oxidation when depositing the vapor deposition material 16 on the film substrate 15.

Further, the vacuum film forming apparatus 30 of the present invention includes means for activating the evaporated deposition material 16 with the plasma 26 in order to deposit the deposition material 16 on the film substrate 15. The evaporated vapor deposition material 16 is a film substrate 1 held by the main roller 14 as vapor deposition particles 25.
5 is deposited. At this time, the vapor deposition particles 25 are activated by passing the plasma 26 before the vapor deposition particles 25 are vapor deposited on the film substrate 15.

  The plasma 26 that activates the vapor deposition particles 25 is preferably a high-density plasma, and any one of hollow cathode discharge, microwave discharge, ICP discharge, and helicon wave discharge can be used.

  As an example of the vacuum film forming apparatus of the present invention, a hollow cathode gun 18 is installed in the vacuum film forming apparatus 30, and an internal electrode 19 positioned inside the hollow cathode gun 18 as an anode or the outside of the hollow cathode gun 18. The external electrode 24 located at is installed.

  The hollow cathode gun 18 is connected to DC power sources 21 and 22 for hollow cathode discharge for generating hollow cathode discharge. For discharge in the hollow cathode gun 18, the anode may be either the internal electrode 19 or the external electrode 24, or both may be used at the same time, and may be used appropriately depending on the application.

  In the hollow cathode discharge, electrons accelerated by a sheath voltage move in a radial direction in a cylindrical cathode formed in a “cylindrical cathode” called a hollow cathode. The electrons are decelerated in the vicinity of the center of the cylinder due to the sheath voltage of the cathode formed in the cylindrical shape, but the decelerated electrons are accelerated again by the sheath voltage formed by the cathode on the counter electrode surface. Thus, kinetic energy is continuously supplied to the electrons.

  In the process in which the electron group having such kinetic energy moves in the radial direction in the cathode, high-density plasma is generated by repeating impact ionization with a gas such as argon supplied to the hollow cathode gun 18. These high-density plasmas can be actively extracted into the film formation chamber 10 due to the pressure difference between the hollow cathode gun 18 and the vacuum-formed film formation chamber 10.

  When the internal electrode 19 is used as an anode, the plasma generated from the hollow cathode gun 18 is diffused into the film forming chamber 10 by the bipolar diffusion action, and activation is promoted by giving kinetic energy to the vapor deposition particles 25.

  A part of the vapor deposition particles 25 activated by the plasma becomes ionized vapor deposition particles, and the film base 15 is irradiated with the argon ions for promoting the hollow cathode discharge with the acceleration of the electric field of the plasma sheath.

  On the other hand, the external electrode 24 is an anode for the hollow cathode, like the internal electrode 19, and may be positioned outside the hollow cathode gun 18. More preferably, the external electrode 24 is installed in the vicinity of the vapor deposition material 16 as shown in FIG. By doing so, the vapor deposition particle 25 can be activated efficiently.

  When the external electrode 24 is used as an anode, high-density plasma is generated in the film forming chamber 10 like the plasma 26 in FIG. The vapor deposition particles 25 immediately after evaporation pass through the high-density plasma 26 generated between the hollow cathode gun 18 and the external electrode 24, so that the activation is violently promoted, and the vapor deposition particles 25 only obtain kinetic energy. Instead, it becomes ionized vaporized particles by ionization, and the electric field acceleration of the plasma sheath is obtained and incident on the film substrate 15 including the argon ions.

Therefore, the external electrode 24 is preferably installed at a position where the region where the plasma 26 is generated and the region where the vapor deposition particles 25 are present. However, in order to make maximum use of the energy of the plasma, the evaporation is performed. It may be optimal to irradiate the plasma 26 directly above the space where the material 16 evaporates.

  When the vapor deposition material 16 is an insulating material, the external electrode 24 is contaminated by the vapor deposition material 16 during vapor deposition. When the contamination progresses excessively, electrons do not flow, causing problems such as arcing or inability to sustain discharge. To do. For this reason, the external electrode 24 needs to be devised so that the vapor deposition material 16 does not directly adhere by heating or covering with a cover so that the vapor deposition material 16 does not adhere.

  Further, a plurality of hollow cathode guns 18 may be installed in the vacuum film forming apparatus 30 depending on the size of the film substrate 15 in the width direction. When the external electrode 24 is used as an anode, the number of hollow cathode guns 18 is as large as the number of hollow cathode guns 18. Multiple units may be installed accordingly.

  As for the discharge conditions of the plasma 26, the higher the current value, from several tens of A to several hundreds A per hollow cathode, the higher the plasma density is preferable. On the other hand, in order to increase the amount of gas to be ionized, When the flow rate of the introduced gas is increased, the pressure in the film forming chamber 10 is increased, and particularly when the evaporation rate is high, the mean free path of the vapor deposition particles 25 is shortened.

  As a result, the vapor deposition particles 25 lose kinetic energy, and there is a concern that the film density and adhesion of the film to be formed are reduced depending on the type of the vapor deposition material 16. For this reason, it is desirable to determine the discharge conditions of the hollow cathode in accordance with the type of gas introduced into the hollow cathode, the type and location of the gas introduced from the gas pipe 23, and the type of the vapor deposition material 16.

  When film formation is performed by the vapor deposition method, it is generally difficult to completely eliminate bumping and splash from the vapor deposition material 16. When the splash occurs, the lump including the vapor deposition material 16 jumps out toward the film base material 15 and hits the film base material 15 to cause scratches, and in some cases, lead to large damage such as pinholes and film breakage. .

  These are generated due to various reasons such as impurities contained in the vapor deposition material 16, residual gas such as water existing in a vacuum, or the surface of the vapor deposition material 16 reacts with the reactive gas when a reactive gas is introduced. To do.

  In the present invention, particularly in the process of efficiently performing the reactive vapor deposition process using the high-density plasma 26, the vapor deposition material 16 and the resistance heating crucible 17 are disturbed by the diffusion and progress of electrons in the high-density plasma 26. By forming a simple magnetic field, it is intended to suppress splash due to partial heating of the vapor deposition material 16 and the resistance heating crucible 17.

  In order not to directly expose the plasma 26 to the vapor deposition material 16 or the resistance heating crucible 17, a magnetic field distribution control device 27 is provided, an appropriate orthogonal magnetic field is applied to the film forming chamber 10, and further toward the external electrode 24. The plasma 26 can be induced in the external electrode 24 by further applying an opposite magnetic field that cancels each other. These magnetic fields can be achieved using electromagnets.

  By using the vacuum film forming apparatus of the present invention, it is possible to suppress the splash and bumping generated from the resistance heating crucible 17 in advance and form a film without causing a quality defect.

The gas barrier film formed by the vacuum film forming apparatus of the present invention preferably has a water vapor permeability of 2 g / m ² / day or less. Further, the gas barrier film formed by the vacuum film forming apparatus of the present invention preferably has an oxygen permeability of 3 cc / m ² / day or less.

Using such a gas barrier film, by laminating with other materials to make a gas barrier laminate, water vapor permeability and oxygen permeability can be further lowered, and various functions are added, It can be developed for various purposes.

  Specific examples of the present invention will be described below.

<Example 1>
In the vacuum film forming apparatus 30 shown in FIG. 1, resistance heating is performed while continuously supplying an aluminum wire having a diameter of 15 mm as the vapor deposition material 16 to the resistance heating crucible 17 at a film forming rate of 100 nm / sec. Vapor deposition was performed. At that time, while supplying 200 sccm of argon gas to the hollow cathode gun 18, 35 V and 150 A were discharged to the external electrode 24 to produce a gas barrier film. At this time, a magnetic field of approximately 500 gauss was supplied by the electromagnet of the magnetic field distribution control device 27. As the substrate, a web-like polyethylene terephthalate film having a width of 500 mm and a thickness of 12 μm was used. The gas barrier film of Example 1 was created as described above.

  Below, the comparative example of this invention is demonstrated.

<Comparative Example 1>
A gas barrier film of Comparative Example 1 was prepared in the same manner as in Example 1 except that a magnetic field of approximately 500 Gauss was not supplied by the electromagnet of the magnetic field distribution control device 27.

<Evaluation method>
About the created gas barrier film of Example 1 and Comparative Example 1, the following items were compared and evaluated.

<Number of defects>
About the created gas barrier film of Example 1 and Comparative Example 1, the number of pinhole defects generated due to bumping and splash was investigated.

(Evaluation method)
About the produced film 1000m, the number of pinhole defects and foreign material defects was counted and converted as the number of defects per square meter.

<Water vapor permeability>
About the created gas barrier film of Example 1 and Comparative Example 1, water vapor permeability was measured by the following method.

(Evaluation method)
The water vapor permeability was measured by the MOCON method. The measuring device used was measured by MOCON PERMATRAN (R) 3/33 at 40 ° C. and 90% Rh.

<Oxygen permeability>
About the created gas barrier film of Example 1 and Comparative Example 1, the oxygen permeability was measured by the following method.

(Evaluation method)
The oxygen permeability was measured by MOCON OX-TRAN (R) 2/20 at 37 ° C. and 70% Rh.

  Table 1 shows the number of defects, water vapor permeability, and oxygen permeability evaluated for the gas barrier films of Example 1 and Comparative Example 1.

Below, the comparison result of an Example and a comparative example is demonstrated.

<Comparison result>
The gas barrier film of Comparative Example 1 produced without supplying a magnetic field with a magnetic field distribution control device had a large number of defects, water vapor permeability was not so low, and oxygen permeability was not so low. In particular, there was no oxygen barrier property at the pinhole generation portion.

On the other hand, the barrier film of Example 1 prepared by using the vacuum film formation apparatus of the present invention and supplying a magnetic field with the magnetic field distribution control apparatus has a very high defect despite being formed at a high speed of 100 nm / sec. The water vapor permeability was 2 g / m ² / day or less and the oxygen permeability was 3 cc / m ² / day or less, and high water vapor barrier properties and oxygen barrier properties were obtained.

  The vacuum film forming apparatus of the present invention is an apparatus for producing a barrier film having a high oxygen and water vapor barrier property, and the produced barrier film is laminated with other members to form a gas barrier laminate as a barrier member. Can be used.

DESCRIPTION OF SYMBOLS 10 ... Film-forming chamber 11 ... Winding chamber 12 ... Unwinding roller 13 ... Winding roller 14 ... Main roller 15 ... Film base material 16 ... Deposition material 17 ... · Resistance heating crucible 18 · · · Hollow cathode gun 19 · · · Internal electrode 20 · Resistance heating DC power supply 21 and 22 · · · Hollow cathode discharge DC power supply 23 · · · Gas pipe 24 · · · External electrode 25 ... deposited particles 26 ... plasma 27 ... magnetic field distribution control device 30 ... vacuum film forming device

Claims (10)

  A vacuum film forming apparatus for forming a thin film on a substrate by a vacuum vapor deposition method, comprising: means for generating activated plasma by generating plasma separately from an evaporation means for evaporating an evaporation material in an evaporation space. And the vacuum film-forming apparatus characterized by comprising the magnetic field distribution control apparatus which controls a plasma flow so that the surface of the said base material may not be exposed to the said plasma.   2. The substrate according to claim 1, wherein the substrate is a web-like film substrate, and includes a conveying means for conveying the film substrate by roll-to-roll, and a thin film is formed on the film substrate. The vacuum film-forming apparatus described in 1.   The vacuum film forming apparatus according to claim 1, wherein the magnetic field distribution control device is covered with a heat insulating material in order to withstand a temperature rise due to generation of the plasma and evaporation of the vapor deposition material.   The vacuum film-forming apparatus according to any one of claims 1 to 3, wherein the vacuum evaporation method is a resistance heating evaporation method.   5. The vacuum film forming apparatus according to claim 4, wherein, in the vacuum vapor deposition method using resistance heating, a metal wire having the vapor deposition material or a partial composition of the vapor deposition material is provided to a resistance heating boat.   6. The vacuum forming apparatus according to claim 1, wherein the plasma generating means uses any one of hollow cathode discharge, microwave discharge, ICP discharge, and helicon wave discharge. Membrane device.   7. The vacuum film forming apparatus according to claim 6, wherein the plasma generating means is hollow cathode discharge, and at least one anode with respect to the hollow cathode is in the vicinity of the vapor deposition material. A gas barrier film produced using the vacuum film forming apparatus according to any one of claims 1 to 7 and having a water vapor permeability of 2 g / m ² / day or less. A gas barrier film produced using the vacuum film forming apparatus according to claim 1 and having an oxygen permeability of 3 cc / m ² / day or less.   A gas barrier laminate produced by using the gas barrier film according to claim 8 or 9.