JP2014065198A - Gas barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film with which gas barrier performance is improved while further reducing deterioration of the gas barrier performance caused by film thickness reduction resulting from production speed increase.SOLUTION: A gas barrier film is configured in such a way that a gas barrier layer 11 having film thickness of 5 to 30 nm and having a difference between the maximum value and the minimum value of moisture permeability of 1 g/m/day or less is formed by making a plastic film 10 pass through an atmosphere in which a vapor deposition material is heated to generate vapor deposition particles and ion plating is performed with high density plasma.

Description

  The present invention relates to an exterior material for medical drugs and inkjet tank members, an export packaging material such as resin, an exterior material for industrial materials such as a solar battery back sheet, and a gas barrier film used for a food packaging material.

  For packaging materials for medical drugs and inkjet tank members, and export packaging materials such as resins, they are stable in accelerated tests at high temperatures and high humidity, prevention of solvent evaporation at high temperatures, and transportation by sea (especially directly below the equator). Therefore, there is a demand for a package that exhibits excellent oxygen barrier properties and water vapor barrier properties.

  The solar cell protection sheet is placed on the back side of the solar cell to prevent deterioration due to humidity of the patterned silicon thin film that is the electromotive part of the solar cell module, and simultaneously blocks gases such as oxygen and water vapor. There is a need for durability that does not degrade the gas barrier performance even when used under harsh conditions such as outdoors.

  It is necessary to protect the contents of packaging materials used for packaging hard disks, semiconductor modules, foods and pharmaceuticals. Particularly in food packaging, it is necessary to suppress the oxidation and alteration of proteins, fats and oils, and to maintain the taste and freshness. In addition, pharmaceuticals that require handling in a sterile state are required to suppress the alteration of the active ingredient and maintain its efficacy. In order to protect the quality of these contents, there is a demand for a package having a gas barrier property that blocks oxygen, water vapor, and other gases that alter the contents.

  Conventionally, as a package made of a plastic film, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (PAN), which are relatively excellent in gas barrier performance among polymers. Etc.) or plastic films laminated or coated with these resins have been used favorably.

However, these films are highly temperature-dependent, and the gas barrier performance is deteriorated at high temperatures or high humidity. In food packaging applications, gas barriers are obtained when boil treatment or retort treatment at high temperature and high pressure is performed. There is a risk that the performance will deteriorate significantly. In addition, the gas barrier laminate using the PVDC polymer resin composition has low humidity dependency but temperature dependency, and also has high gas barrier performance (for example, 1 cc / m ² · day · atm or less). It has the problem that it cannot be obtained.

  In addition, since PVDC and PAN have a high risk of generating harmful substances during disposal and incineration, a metal foil such as aluminum is used for packaging that has high moisture resistance and requires high gas barrier performance. It is possible to guarantee the gas barrier performance by such as.

  However, since the metal foil is opaque, it is difficult to identify the contents through the packaging material, and there is a problem that the contents cannot be inspected by the metal detector and cannot be heat-treated in the microwave oven.

  In order to solve these problems, many gas barrier films in which a metal oxide film made of silicon oxide, aluminum oxide or the like is formed on a plastic film are generally put into practical use.

  As a method of forming such a metal oxide film, a film having excellent productivity can be formed by using a dry coating method, particularly a vacuum deposition method. Examples of dry coating methods other than vacuum deposition include sputtering and chemical vapor deposition (CVD). Sputtering is superior in gas barrier performance, but has the disadvantage of significantly slowing production speed. Have. Even in the case of chemical vapor deposition (CVD), when it is selected as the gas barrier layer formation, there is a demerit that the production rate is slower than the vacuum deposition method.

  However, when the metal oxide film production rate is increased with the goal of further improving productivity and cost reduction, the previously obtained gas barrier performance is greatly improved due to the decrease in film thickness caused by the increase in production rate. In order to achieve further improvement in productivity and cost reduction, there is a need for diligent ingenuity.

  One of the methods for preventing the gas barrier performance from being lowered due to the decrease in the film thickness is a method for forming a denser film, and one of them is a pressure gradient type plasma gun used as a material evaporation method. A vapor deposition method has been proposed (for example, Patent Document 1). In this method, the plasma emitted from the plasma gun is focused to the material by converging it using a magnetic field, etc., and the material is heated and evaporated. At the same time, the atoms and molecules being evaporated are emitted from the plasma gun. By passing the light, it is activated and incident on the base material with higher kinetic energy than that during evaporation, so that it is possible to obtain a denser film than a normal vapor deposition method.

  However, in the method proposed in Patent Document 1, material evaporation and activation by plasma can be performed at the same time, which is less complicated and advantageous in terms of apparatus cost. On the other hand, the material evaporation rate and plasma density are unambiguous. Therefore, there is a problem that it is difficult to improve productivity.

JP 2005-34831 A

  The present invention has been made in view of the above circumstances, and is capable of realizing both productivity and gas barrier properties, and prevents deterioration in gas barrier performance due to a decrease in film thickness due to an increase in production speed. Another object is to provide a gas barrier film capable of improving the gas barrier performance.

The invention according to claim 1 has a film thickness of 5 to 30 nm by heating a vapor deposition material to generate vapor deposition particles and passing the substrate through an ion-plated atmosphere with high-density plasma, and has a water vapor transmission rate. A gas barrier film in which a gas barrier layer having a difference between a maximum value and a minimum value of 1 g / m ² · day or less is formed.

  According to a second aspect of the present invention, in the gas barrier film according to the first aspect, the means for generating the vapor deposition particles is performed by any one of an electron beam vapor deposition method, a resistance heating method, and a high frequency induction heating method. It is characterized by.

  According to a third aspect of the present invention, in the gas barrier film according to the first or second aspect, the means for generating the high-density plasma is any one of ICP plasma, helicon wave plasma, microwave plasma, and holo cathode discharge. It is characterized by having executed.

  The invention according to claim 4 is the gas barrier film according to any one of claims 1 to 3, wherein the gas barrier layer includes a silicon oxide film, a silicon nitride film, a silicon oxynitride film, an aluminum oxide film, an aluminum nitride film, It is characterized by being formed of at least one of an aluminum oxynitride film and a magnesium oxide film.

  ADVANTAGE OF THE INVENTION According to this invention, the gas barrier film excellent in gas barrier performance can be provided, making deterioration of the gas barrier performance by the reduction | decrease of the film thickness resulting from the increase in production rate smaller.

It is sectional drawing shown in order to demonstrate the structure of the gas barrier plastic film which concerns on one embodiment of this invention. It is the block diagram shown in order to demonstrate the manufacturing apparatus with which it uses for manufacture of FIG. It is the characteristic view which compared and showed the gas-barrier property of Examples 1-3 by FIG. 1 and the comparative example 1. FIG.

  Hereinafter, a gas barrier plastic film according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a main part of a gas barrier plastic film according to an embodiment of the present invention. A gas barrier layer 11 is formed on a plastic film 10 constituting a substrate.

  The film structure is not limited to the above. For example, for the purpose of improving gas barrier performance and adhesion, insertion of an anchor coat layer based on a resin material or surface treatment using plasma is performed. It may be.

  The plastic film 10 is not particularly limited, and a known film can be used. For example, polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene naphthalate, polyethylene terephthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polystyrene, ethylene vinyl alcohol, polyvinyl chloride, polyimide, polyvinyl alcohol , Polycarbonate, polyethersulfone, acrylic, cellulose-based (triacetylcellulose, diacetylcellulose, etc.), and the like. From the viewpoint of appearance and the advantage that the contents can be confirmed, it is preferable to use a transparent film. Also, the thickness is not particularly limited, and practically in the range of 6 to 100 μm is preferable in consideration of processability when forming a gas barrier film.

Examples of the gas barrier layer 11 include a silicon oxide film, a silicon nitride film, a silicon oxynitride film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, and a magnesium oxide film. The vapor deposition material used when vapor-depositing these is not particularly limited, and known materials can be used. For example, in the case of a silicon oxide film, silicon (Si), silicon monoxide (SiO), silicon dioxide (SiO ₂ ), or a mixture thereof can be used, but not limited thereto. Further, a silicon oxide film may be obtained by using a reactive gas such as oxygen in combination with the deposition of the above materials.

The composition of the gas barrier layer 11 is not particularly limited. For example, in the case of a silicon oxide film described by SiO 2 _X , by setting the composition of the gas barrier layer 11 to 1.5 ≦ x ≦ 2.2, The gas barrier layer 11 having both transparency and gas barrier properties can be formed. In consideration of compatibility between transparency and gas barrier properties, 1.6 ≦ x <1.9 is more preferable. As a method of controlling the value of x, there is a method of introducing a gas that becomes an oxidizing agent such as oxygen during film formation or changing the value of x in the vapor deposition material to be used. By introducing a large amount of oxidizing gas or increasing the value of x in the vapor deposition material to be used, the value of x in the gas barrier layer 11 increases. When the composition of the gas barrier layer 11 is x <1.5, the yellow color of the gas barrier layer 3 becomes strong, and transparency may not be ensured depending on the film thickness, which may impair the appearance. Moreover, when the composition of the gas barrier layer 11 is 2.2 <x, transparency can be secured, but the gas barrier performance may not be exhibited.

  The film thickness of the gas barrier layer 11 is preferably 5 to 30 nm in consideration of productivity and gas barrier properties. If it is 5 nm or less, it is difficult to obtain a stable gas barrier performance, and if it is 30 nm or more, the production rate may be slow and the cost may be increased.

  In addition, when the gas barrier layer 11 is formed, the conventional vacuum deposition method causes a sudden change in the film thickness and the gas barrier performance deteriorates if the film thickness becomes thinner than the target film thickness. As a result, productivity may be reduced. As a countermeasure, there is a technique for improving the film quality and suppressing the fluctuation of the gas barrier performance with respect to the fluctuation of the film thickness. Among them, a technique using plasma is conceivable. When depositing at a high deposition rate, the number of vapor deposition particles is very large, so if it is not a method that can express a high plasma density, the number of particles that are converted into plasma is smaller than vapor deposition particles, and the film quality is improved. It is difficult to express changes to be made. For this reason, it is optimal to use any one of the ICP plasma method, the helicon wave plasma method, the microwave plasma method, and the holocathode discharge method as means for developing a high plasma density.

Furthermore, there is no problem even if a protective layer or the like is provided on the gas barrier layer 11. As the protective layer, it is desirable to provide a coating film using a metal alkoxide. Specifically, it is represented by the general formula R ¹ (M-OR ² ) (where R ¹ and R ² are organic groups having 1 to 8 carbon atoms, M is a metal atom), and the metal atom is Si, Ti, Al, Zr, etc. can be mentioned. Moreover, there is no problem even if a nylon film or a polypropylene film is laminated thereon.

R ¹ (Si—OR ² ) in which the metal M is Si includes tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxy. A silane etc. can be mentioned.

Examples of R ¹ (Zr—OR ² ) in which the metal M is Zr include tetramethoxyzirconium, tetraethoxyzirconium, tetraisopropoxyzirconium, and tetrabutoxyzirconium.

Examples of R ¹ (Ti—OR ² ) in which the metal M is Ti include tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, and tetrabutoxytitanium.

Examples of R ¹ (Al—OR ² ) in which the metal M is Al include tetramethoxyaluminum, tetraethoxyaluminum, tetraisopropoxyaluminum, and tetrabutoxyaluminum.

  The metal alkoxide may be used alone or in combination of two or more. Moreover, although acrylic acid, polyvinyl alcohol, a urethane compound, and a polyester compound may be mixed, it is desirable to mix a swellable material.

  When laminating, it is preferable to use a urethane-based adhesive as the adhesive, and as a laminating method, it is preferable to perform lamination by a dry lamination method, a non-solvent lamination method, an extrusion lamination method, a knee lamination method, or the like.

  Here, as a method of laminating and forming the gas barrier layer 11 on the plastic film 10, for example, a manufacturing apparatus including the vacuum chamber 20 shown in FIG. 2 is used.

  That is, the plastic film 10 is wound around the unwinding roller 22 in the vacuum chamber 20, and the leading end is wound around the winding roller 24 via a plurality of guide rollers 21 and film forming rolls 23. Then, it is conveyed from the unwinding roller 22 to the winding roller 24.

  Among these, a part of the film forming roll 23 is disposed in the film forming chamber 201 so as to be rotatably exposed. In this film forming chamber 201, a crucible 25 in which a vapor deposition material 251 is accommodated is disposed, and a rectilinear electron beam gun 26 constituting vapor deposition means corresponding to this crucible 25, and a reaction constituting means for introducing reactive gas. A sex gas introduction pipe 27 is arranged.

  In the above configuration, the plastic film 10 wound around the unwinding roller 22 is sequentially wound around the winding roller 24 via the guide roller 21 and the film forming roll 23.

  At the same time, the vapor deposition material 251 accommodated in the crucible 24 in the film forming chamber is heated by the electron beam from the straight electron beam gun 26 to become vapor, which is vapor-deposited on the plastic film 10 passing through the film forming roll. At this time, in the film forming chamber 201, an atmosphere of high-density plasma 29 is generated in which the vapor deposition particles 28 are ion-plated by the action of the reactive gas introduced from the reactive gas introduction pipe 27. It is deposited on the film 10.

  The case where the electron beam vapor deposition method in which the linear electron beam gun 27 is installed is described as the means for heating the vapor deposition material 251 of the crucible 25 has been described. On the other hand, the material may be evaporated by heating using a resistance heating method or a high frequency induction heating method. The electron beam vapor deposition method is not limited to this, but may be a deflected electron beam gun, but a Pierce type flat cathode electron gun capable of supplying a large amount of power in order to develop a high film forming speed, etc. However, it is not limited to this. Further, as the resistance heating method, a method of directly resistance heating the crucible 25 filled with the vapor deposition material 251 may be used, or a resistance heating method of feeding a metal wire to the resistance heating unit is not a problem. . Both methods are required to have an apparatus configuration capable of exhibiting a high film formation rate.

  The manufacturing apparatus configuration is not limited to the configuration shown in FIG. 2, and there is no problem even if a plasma processing apparatus is installed if necessary. The arrangement of the rollers, the method for introducing the reaction gas, etc. are not particularly limited.

As described above, the gas barrier film is formed by laminating the gas barrier layer 11 on the plastic film 10 by using both the vapor deposition method and the means for generating high-density plasma, thereby changing the film thickness of the gas barrier layer 11. Is also characterized by a very small change in water vapor transmission rate. Specifically, when the film thickness of the gas barrier layer 11 is changed from 5 to 30 nm, the difference between the maximum value and the minimum value of the water vapor transmission rate at each film thickness can be suppressed to 1 g / m ² · day or less. it can. The gas barrier plastic film including the gas barrier layer 11 having such a film quality can improve the gas barrier performance while further reducing the deterioration of the gas barrier performance due to the decrease in the film thickness due to the increase in production speed.

  Hereinafter, while producing Examples 1-3 using high-density plasma in combination as a gas barrier film according to an embodiment of the present invention, Comparative Example 1 not using high-density plasma is produced and compared.

<Example 1>
As Example 1, a gas barrier layer made of SiOx was formed on one surface of a 12 μm thick polyethylene terephthalate film (P60 manufactured by Toray Industries, Inc.) using the manufacturing apparatus of FIG. At that time, in order to change the film thickness of the gas barrier layer, the film forming speed was changed. When this film was formed, high-density plasma by holocathode discharge with current controlled to 100 A was used in combination.

<Example 2>
As Example 2, a gas barrier layer made of SiOx was formed on one side of a 12 μm thick polyethylene terephthalate film (P60 manufactured by Toray Industries, Inc.) using the manufacturing apparatus of FIG. At that time, in order to change the film thickness of the gas barrier layer, the film forming speed was changed. When this film was formed, high density plasma by 10 kW ICP discharge was used in combination.

<Example 3>
As Example 3, a gas barrier layer made of SiOx was formed on one side of a 12 μm thick polyethylene terephthalate film (P60 manufactured by Toray Industries, Inc.) using the manufacturing apparatus of FIG. At that time, in order to change the film thickness of the gas barrier layer, the film forming speed was changed. When this film was formed, high-density plasma by 6 kW microwave discharge was used in combination.

<Comparative example 1>
As Comparative Example 1, a gas barrier layer made of SiOx was formed on one side of a 12 μm-thick polyethylene terephthalate film (Toray P60) using the manufacturing apparatus of FIG. At that time, in order to change the film thickness of the gas barrier layer, the film forming speed was changed. When this film was formed, high-density plasma was not used in combination.

<Evaluation 1>
The water vapor transmission rates of Examples 1 to 3 and Comparative Example 1 were measured in a 40 ° C. and 90% RH atmosphere using a water vapor transmission rate measuring device (MOCON PERMATRAN 3/21 manufactured by Modern Control).

<Evaluation 2>
The film thicknesses of Examples 1 to 3 and Comparative Example 1 were measured using a wavelength dispersion compact fluorescent X-ray analyzer (Supermini manufactured by Rigaku).

  When this measurement result is arranged, the relationship between the water vapor transmission rate and the film thickness in Examples 1 to 3 and Comparative Example 1 is as shown in FIG. 3, and the gas barrier property with respect to the film thickness in Examples 1 to 3 is a comparative example. It was confirmed that it was better than 1.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problems described in the column of problems to be solved by the invention can be solved, and the effects described in the effects of the invention can be obtained. In some cases, a configuration from which this configuration requirement is deleted can be extracted as an invention.

  ADVANTAGE OF THE INVENTION According to this invention, the gas barrier film suitable as a packaging material for industrial materials, such as packaging materials for medical drugs and inkjet tank members, export packaging materials such as resins, solar battery back sheets, and food packaging materials can be provided. it can.

DESCRIPTION OF SYMBOLS 10 ... Plastic film 11 ... Gas barrier layer 20 ... Vacuum chamber 201 ... Film forming chamber 21 ... Guide roller 22 ... Unwinding roller 23 ... Film forming roll 24 ... Winding roller 25 ... Crucible 251 ... Vapor deposition material 26 ... Straight electron beam gun 27 ... reactive gas introduction pipe 28 ... deposited particles 29 ... high density plasma

Claims (4)

The substrate is heated to the vapor deposition material to generate vapor deposition particles, passed through an ion-plated atmosphere with high density plasma, has a thickness of 5 to 30 nm, and has a maximum and minimum water vapor transmission rate. A gas barrier film, wherein a gas barrier layer having a difference of 1 g / m ² · day or less is formed.   The gas barrier film according to claim 1, wherein the means for generating the vapor deposition particles is any one of an electron beam vapor deposition method, a resistance heating method, and a high frequency induction heating method.   The gas barrier film according to claim 1 or 2, wherein the means for generating the high-density plasma is any one of ICP plasma, helicon wave plasma, microwave plasma, and holo cathode discharge. The gas barrier layer includes a silicon oxide film, a silicon nitride film, a silicon oxynitride film, an aluminum oxide film,
4. The gas barrier film according to claim 1, comprising at least one of an aluminum nitride film, an aluminum oxynitride film, and a magnesium oxide film.

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