JP2005059537A - Gas-barrier film and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-barrier film which has an inorganic vapor deposition layer of a metal or an inorganic oxide on at least one side of a plastic film substrate, is improved in bending resistance and oxygen-barrier properties of an inorganic vapor deposition film, prevents the improved properties from being deteriorated by moisture, and has moisture resistance and a method for producing the film. <P>SOLUTION: The inorganic vapor deposition layer of the metal or the inorganic oxide and an organic vapor deposition layer of a 1,3,5-triazine derivative are formed in turn on at least one side of the plastic film substrate, and reactive ion etching (RIE) treatment using plasma is applied to the organic vapor deposition layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas barrier film suitably used in the field of packaging foods, pharmaceuticals, precision electronic components and the like, and a method for producing the same.

  In recent years, packaging materials used for packaging foods, non-foods, pharmaceuticals, etc. have altered oxygen, water vapor, and other contents that permeate the packaging material in order to suppress the alteration of the contents and retain their functions and properties. It is necessary to prevent the influence of the gas to be generated, and it is required to have a gas barrier property and the like for blocking these. Therefore, conventionally, a packaging material using a metal foil such as aluminum, which is less affected by temperature, humidity and the like, as a gas barrier layer has been generally used.

  However, packaging materials using metal foils such as aluminum have a high gas barrier property with very little influence of temperature and humidity. There was a problem that it had to be treated as an incombustible material at the time of disposal.

  Therefore, as a packaging material that overcomes these drawbacks, an inorganic material such as a metal such as aluminum or an inorganic oxide such as silicon oxide or aluminum oxide is formed on a polymer film by a thin film forming means such as a vacuum deposition method or a sputtering method. A vapor deposition film having a vapor deposition layer has been developed. These vapor-deposited films are known to have gas barrier properties against oxygen, water vapor and the like, and are suitable as packaging materials.

  However, these inorganic vapor-deposited films have a disadvantage of low bending resistance derived from the inorganic layer. In order to overcome this problem, a technique has been established in which a thin film layer made of a barrier polymer such as PVA is provided by coating on an inorganic vapor deposition layer for the purpose of providing protection and assisting oxygen barrier properties. However, while this method that can compensate for the disadvantages of the inorganic vapor-deposited film is performed under normal pressure, the formation of the inorganic vapor-deposited layer is performed under vacuum, and in the production method that combines these, the production process Has the disadvantage of becoming complicated.

If the protective coating on the inorganic vapor-deposited layer can be performed in a vacuum, the manufacturing method performed by combining both of them can simplify the process and obtain an inorganic vapor-deposited film at a low cost. It is also possible to protect the deposited layer. As a technology that enables such a protective coating, there is a technology disclosed in Patent Document 1. Such a technique is an effective means for forming an organic thin film in a vacuum. Therefore, if a thin film of a 1,3,5-triazine derivative, for example, is formed on the inorganic vapor deposition layer by such an organic thin film formation technique, it has excellent bending resistance and scratch resistance and oxygen barrier properties are added. An inorganic vapor deposition film can be obtained.
Special table 2002-518219 gazette Japanese Patent Laid-Open No. 2002-19090

  The present invention has been made in view of the above-described problems, and has a predetermined presence / absence organic vapor deposition on an inorganic vapor deposition film having an inorganic vapor deposition layer made of a metal or an inorganic oxide on at least one surface of a plastic film substrate. In addition to improving the bending resistance and oxygen permeation resistance by providing further layers, the various properties improved by the addition of the inorganic vapor deposition layer are not reduced by moisture. It aims at providing the gas-barrier film which has, and its manufacturing method.

  In view of the above situation, the invention according to claim 1 is composed of an inorganic vapor deposition layer made of a metal or an inorganic oxide and a 1,3,5-triazine derivative on at least one surface of a plastic film substrate. A gas barrier film characterized in that an organic vapor deposition layer is sequentially provided and a reactive ion etching process using plasma is applied to the organic vapor deposition layer made of the 1,3,5-triazine derivative. It is.

  The invention described in claim 2 is characterized in that, in the gas barrier film according to claim 1, the metal constituting the inorganic vapor deposition layer is any one of aluminum, tin, titanium, or a mixture thereof.

  Furthermore, the invention according to claim 3 is the gas barrier film according to claim 1, wherein the inorganic oxide constituting the inorganic vapor deposition layer is any one of aluminum oxide, silicon oxide, or a mixture thereof. And

  Furthermore, in the invention described in claim 4, an inorganic vapor deposition layer made of a metal or an inorganic oxide and an organic vapor deposition layer made of a 1,3,5-triazine derivative are sequentially provided on at least one surface of the plastic film substrate. After that, the organic vapor deposition layer made of the 1,3,5-triazine derivative is subjected to a reactive ion etching process using plasma to improve the moisture resistance. .

Furthermore, the invention according to claim 5 is the method for producing a gas barrier film according to claim 4, wherein the reactive ion etching process using plasma has a self-bias value of 200 V or more and 2000 V or less, and Ed = wherein the Ed value defined by plasma density × processing time is treatment with 100V · s · m ^-2 higher 10000V · s · m ^-2 cold plasma or less.

  Furthermore, the invention according to claim 6 is the method for producing a gas barrier film according to claim 4, wherein the inorganic vapor deposition layer made of the metal or the inorganic oxide and the organic vapor deposition layer made of the 1,3,5-triazine derivative. Further, the reactive ion etching process using the plasma of the organic vapor deposition layer made of the 1,3,5-triazine derivative is performed by the same film forming machine (in-line film forming machine).

  The gas barrier film of the present invention has an organic vapor deposition layer composed of a 1,3,5-triazine derivative on an inorganic vapor deposition film having an inorganic vapor deposition layer composed of a metal or an inorganic oxide on at least one surface of a plastic film substrate. By attaching, not only the bending resistance and oxygen permeation resistance are improved, but also the various characteristics improved by the inorganic vapor deposition layer are not deteriorated by moisture. Therefore, it is possible to provide a packaging material with a wide range of practical use that is used for packaging foods, non-foods such as pharmaceuticals and electronic components.

  Moreover, since the inorganic vapor deposition layer and the organic vapor deposition layer constituting the gas barrier film can be formed in-line in the same vacuum atmosphere, the manufacturing process is simplified, and not only a gas barrier film can be obtained at a low cost but also an inorganic substance in the production. It is also possible to protect the deposited layer.

  The gas barrier film of the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory view showing a schematic cross-sectional structure of a gas barrier film of the present invention. This gas barrier film is formed on one surface of a plastic film substrate 1 by depositing an inorganic vapor deposition layer (hereinafter referred to as an inorganic vapor deposition layer) 2 made of a metal or an inorganic oxide and an organic vapor deposition made of a 1,3,5-triazine derivative. Layers (hereinafter referred to as organic vapor deposition layers) 3 are sequentially provided, and the organic vapor deposition layer 3 is provided with a post-treatment layer 4 that is subjected to post-treatment by reactive ion etching (RIE) using plasma. Has been built.

  The plastic film substrate 1 is made of a plastic material, and is preferably transparent if possible in order to make use of the transparency of the inorganic vapor deposition layer 2 and the organic vapor deposition layer 3 described later. Examples of such plastic film substrate 1 include polyester films made of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films made of polyethylene, polypropylene, etc., polystyrene films, polyamide films, polycarbonate films, poly An acrylonitrile film, a polyimide film, etc. are mentioned. Further, the plastic film substrate 1 may be either stretched or unstretched, but is preferably excellent in mechanical strength and dimensional stability. Among these, a polyethylene terephthalate film or a polyamide film arbitrarily stretched in the biaxial direction is preferably used. In addition, various well-known additives and stabilizers such as an antistatic agent, an ultraviolet ray inhibitor, a plasticizer, and a lubricant are applied to the surface of the plastic film substrate 1 opposite to the surface on which the inorganic vapor deposition layer 2 is provided. You may keep it.

  The thickness of the plastic film substrate 1 is not particularly limited, and considering the suitability as a packaging material, the thickness of the plastic film substrate 1 is not only a single layer structure but also a laminated structure in which films having different properties are laminated. Also good. In view of providing the inorganic vapor deposition layer 2 and the organic vapor deposition layer 3 in a stacked manner and workability when forming a primer layer for forming a packaging material, a range of 3 to 200 μm is preferable, particularly 6 More preferably, it is set to ˜30 μm.

  On the other hand, the inorganic vapor deposition layer 2 is a layer provided for exhibiting excellent gas barrier properties, and is a vapor deposition thin film made of a metal such as aluminum or an inorganic oxide such as silicon oxide or magnesium oxide. The optimum thickness of the inorganic vapor deposition layer 2 varies depending on the type and configuration of the metal or inorganic oxide used, but is generally within the range of 5 to 300 nm, and the value is appropriately selected. However, if the thickness is less than 5 nm, it may be difficult to obtain a uniform film, or the gas barrier property may not be sufficiently exhibited, and the function as a gas barrier material may not be sufficiently achieved. On the other hand, when the thickness exceeds 300 nm, flexibility cannot be maintained in the thin film, and the thin film may be cracked by applying external force such as bending or pulling after the film formation. More preferably, it exists in the range of 10-150 nm.

  As a method for forming the inorganic vapor deposition layer 2 on the plastic film substrate 1, various thin film forming methods can be applied. Generally, it may be formed by a vacuum deposition method, but other thin film forming methods such as a sputtering method, an ion plating method, and a plasma vapor deposition method (CVD) can also be used. However, considering productivity, the vacuum deposition method is the best at present. In addition, as a heating means of the vacuum evaporation method, an appropriate method may be selected and used from an electron beam heating method, a resistance heating method, an induction heating method, and the like. It is more preferable to use a wire heating method. Further, in order to further improve the adhesion between the inorganic vapor deposition layer 2 and the plastic film substrate 1 and the denseness of the thin film layer formed by vapor deposition, it is possible to perform vapor deposition using a plasma assist method or an ion beam assist method. It is.

On the other hand, the organic vapor deposition layer 3 is provided in contact with the inorganic vapor deposition layer 2 and is a layer made of a 1,3,5-triazine derivative. The organic vapor deposition layer 3 compensates for the low flex resistance of the laminate having excellent gas barrier properties, which is a two-layer structure of the plastic film substrate 1 and the inorganic vapor deposition layer 2, and improves the scratch resistance. This layer is provided to further improve the oxygen permeation resistance. Therefore, like the inorganic vapor deposition layer 2, the thickness of the inorganic vapor deposition layer 3 is generally preferably in the range of 5 to 300 nm. If the thickness is less than 5 nm, a uniform film may not be obtained, and the above-described characteristics may not be sufficiently exhibited because the thickness is not sufficient. Further, when the thickness exceeds 300 nm, it takes more time to form a film, and when it is combined with film formation of an inorganic vapor deposition layer in-line, a problem arises in productivity. In consideration of productivity, it is more preferable that the thickness is 10 to 100 nm.

  The organic vapor deposition layer 3 is formed by, for example, a vacuum vapor deposition method. As a heating means at this time, methods such as an electron beam heating method, a resistance heating method, and an induction heating method can be used. Among these, it is more preferable to use the resistance heating method in consideration of the apparatus cost, controllability, and the like. Moreover, in order to improve the adhesiveness or denseness with the inorganic material vapor deposition layer 2, it can also vapor-deposit using a plasma assist method or an ion beam assist method.

  By providing the organic vapor deposition layer 3, the low flexibility can be compensated and the scratch resistance and oxygen permeation resistance can be improved. However, the layer made of the 1,3,5-triazine derivative has a moisture content. However, the oxygen barrier property derived from the 1,3,5-triazine derivative-deposited thin film is reduced by moisture absorption in the layer.

  This influence of moisture can occur from the front and back of the 1,3,5-triazine derivative-deposited thin film. However, the good vapor barrier property contributes to the inorganic vapor deposition layer 2 side, and the moisture absorption deterioration of the 1,3,5-triazine derivative vapor deposition layer is minimized. On the other hand, on the side where the vapor deposition layer of the 1,3,5-triazine derivative is exposed, the problem of moisture absorption deterioration is exposed in a post-process after vapor deposition. In order to solve this problem, it is conceivable to improve the moisture resistance by modifying the surface layer of the 1,3,5-triazine derivative deposited surface layer (dense by cross-linking) by in-line post-treatment using plasma (for example, , See Patent Document 2).

  However, the conventional plasma treatment is performed not on the drum side with the base material on which the electrode for applying a voltage for generating plasma is to be processed but on the opposite side. In the case of this apparatus, since the base material is installed on the anode side, a high self-bias cannot be obtained, and as a result, a high treatment effect cannot be exhibited.

  In order to obtain a high self-bias, a DC discharge method can be used. However, if a high bias voltage is obtained by this method, the plasma mode changes from glow to arc, so that a uniform treatment over a large area is possible. Cannot be done.

  Therefore, in the present invention, reactive ion etching treatment using plasma is performed on the organic vapor deposition layer 3 provided by being laminated on the inorganic vapor deposition layer 2, and at least the surface thereof is cross-linked so that the organic vapor deposition layer 3 is dense. To improve the moisture resistance. The post-processing layer 4 shown in FIG. 1 is a layer constructed in the organic vapor deposition layer 3 in this way.

  Argon, oxygen, nitrogen, hydrogen, or the like can be used as a gas for performing post-processing by reactive ion etching using plasma. These gases may be used alone, or two or more kinds of gases may be mixed and used. Moreover, you may process continuously using two processor.

The processing conditions indicated by the processing speed, energy level, and the like in post-processing by reactive ion etching using plasma should be appropriately set according to the type, application, discharge device characteristics, and the like of the plastic film substrate 1. However, the self-bias value of plasma is 200 V or more and 2000 V or less, and Ed = plasma density × Ed value defined by processing time is 100.
It is necessary to V · s · m ^-2 higher 10000V · s · m ^-2 or less. Even a value slightly lower than this can be modified to some extent, but it is less advantageous than untreated products. On the other hand, if the value is high, too strong treatment is applied, the treated surface is deteriorated, and the oxygen barrier property is lowered. Regarding the gas for plasma and its mixing ratio, etc., the flow rate differs depending on the pump performance and mounting position of the pump for gas supply, so that the flow rate differs depending on the application, substrate to be treated, device characteristics, etc. Should be set.

  As described above, the gas barrier film of the present invention and the manufacturing method thereof have been described. However, the present invention is not limited to this. For example, the inorganic deposition layer and the organic deposition layer are disposed on the other side of the plastic film substrate. Also, a laminated structure may be used.

  Furthermore, the gas barrier film having the above-described configuration can be provided as a packaging material by laminating, for example, a printing layer, an intervening film layer, a sealant layer, etc. on the organic vapor deposition layer 3.

  The intervening film layer is provided in order to increase the bag breaking strength and piercing strength at the time of the bag-shaped packaging material, and is generally a biaxially stretched nylon film or a biaxially stretched polyethylene terephthalate film from the viewpoint of mechanical strength and thermal stability. A film selected from among biaxially oriented polypropylene films is laminated and provided. The thickness of the intervening film layer is determined according to the material and required quality, but is generally in the range of 10 to 30 μm.

  Further, the sealant layer is provided so as to serve as an adhesive layer when forming a bag-like package or the like. Examples of the constituent material of the sealant layer include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic. Resins such as acid ester copolymers and metal cross-linked products thereof are used. The thickness of this layer is determined according to the purpose, but is generally in the range of 15 to 200 μm.

  Of course, a printing layer, an intervening film layer, a sealant layer, and the like can be laminated on the opposite surface of the plastic film substrate 1 as necessary.

  Examples of the gas barrier film of the present invention will be specifically described below. The present invention is not limited to these examples.

A PET film having a thickness of 12 μm was used as a plastic film substrate, and an aluminum oxide film was formed on one surface of the PET film by reactive vapor deposition using an electron beam heating method to a thickness of 20 nm. Next, a 1,3,5-triazine derivative was deposited to a thickness of 120 nm by reactive vapor deposition using a resistance heating method on this inorganic vapor deposition layer to provide an organic vapor deposition layer. Subsequently, post-processing by reactive ion etching using plasma on the organic vapor deposition layer made of the 1,3,5-triazine derivative is defined as self-bias value of 900 V and Ed = plasma density × processing time. The gas barrier film of the present invention according to Example 1 was prepared by performing low temperature plasma with an Ed value of 545 V · s · m ⁻² . At this time, a high frequency power source with a frequency of 13.56 MHz was used for the electrodes, and argon was used for the processing gas.

  A gas barrier film of the present invention according to Example 2 was prepared in the same manner as in Example 1 except that an argon / oxygen mixed gas was used as the processing gas.

  A gas barrier film of the present invention according to Example 3 was prepared in the same manner as in Example 1 except that an argon / nitrogen mixed gas was used as the processing gas.

  As a reactive ion etching processing method using plasma, the same method as in Example 1 except that two plasma processing devices were used, the processing with argon was first performed, and then the processing with oxygen was continuously performed. Thus, a gas barrier film of the present invention according to Example 4 was prepared.

  According to Example 5 for comparison in the same manner as in Example 1 except that post-treatment by reactive ion etching using plasma on an organic vapor deposition layer made of a 1,3,5-triazine derivative was not performed. A vapor deposited film was prepared.

  Post-treatment by plasma etching using a general in-line plasma treatment device (the treatment device is on the opposite side of the cooling drum and guide roll) as the treatment method for the organic vapor deposition layer made of 1,3,5-triazine derivative The vapor deposition film which concerns on Example 6 for a comparison was created by the method similar to Example 1 except having used argon gas for process gas.

Using a general in-line plasma treatment device (with a treatment device on the opposite side of the cooling drum and guide roll) as the treatment method, and performing post-processing by plasma etching, except that an argon / oxygen mixed gas is used as the treatment gas Produced the vapor deposition film which concerns on Example 7 for a comparison with the method similar to Example 1. FIG.
<Evaluation>
The oxygen permeability of the film of each example was measured under an atmosphere of 30 ° C.-70% RH using an oxygen permeability meter (MOCON OXTRAN) manufactured by Modern Control. Further, in order to evaluate the tendency of deterioration due to humidity, measurement was also performed in an atmosphere of 30 ° C.-0% RH, and the results are shown in Table 1 together with the measurement results.

It is explanatory drawing which shows the general | schematic cross-section structure of the gas barrier film which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic film base material 2 ... Inorganic substance vapor deposition layer 3 ... Organic substance vapor deposition layer 4 ... Post-processing layer

Claims (6)

  An inorganic vapor deposition layer made of a metal or an inorganic oxide and an organic vapor deposition layer made of a 1,3,5-triazine derivative are sequentially provided on at least one surface of the plastic film substrate. A gas barrier film, wherein a reactive ion etching process using plasma is applied to an organic vapor deposition layer made of a 5-triazine derivative.   2. The gas barrier film according to claim 1, wherein the metal constituting the inorganic vapor deposition layer is aluminum, tin, titanium, or a mixture thereof.   2. The gas barrier film according to claim 1, wherein the inorganic oxide constituting the inorganic vapor deposition layer is aluminum oxide, silicon oxide, or a mixture thereof.   An inorganic vapor deposition layer composed of a metal or an inorganic oxide and an organic vapor deposition layer composed of a 1,3,5-triazine derivative are sequentially provided on at least one surface of the plastic film substrate, and then the 1,3,5-triazine A method for producing a gas barrier film, wherein a reactive ion etching process using plasma is applied to an organic vapor deposition layer made of a derivative to improve moisture resistance. In reactive ion etching processing using plasma, the self-bias value is set to 200 V or more and 2000 V or less, and Ed = plasma density × Ed value defined by processing time is 100 V · s · m ^{−2 to} 10000 V · s · m ^−. 5. The method for producing a gas barrier film according to claim 4, wherein the treatment is performed with a low temperature plasma of ² or less.   Formation of an inorganic vapor deposition layer composed of the metal or inorganic oxide and an organic vapor deposition layer composed of a 1,3,5-triazine derivative, and a plasma applied to the organic vapor deposition layer composed of a 1,3,5-triazine derivative. 5. The method for producing a gas barrier film according to claim 4, wherein the active ion etching process is performed by the same film forming machine (in-line film forming machine).

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