Oxygen barrier laminated film

Abstract

To provide a laminated film which is a film having a metal-deposited layer and is excellent in oxygen barrier property.SOLUTION: There is provided an oxygen-barrier laminated film 10A formed by laminating: a stretched polyvinyl alcohol-based resin layer 12; and a vapor deposited film 14 having a metal-deposited layer 14b. The vapor deposited film having the metal-deposited layer is excellent in vapor barrier property, however, has insufficient oxygen barrier property. The polyvinyl alcohol-based resin layer, on the other hand, is excellent in oxygen barrier property, and the oxygen barrier property of the polyvinyl alcohol-based resin layer is further enhanced since the polyvinyl alcohol-based resin layer is stretched, therefore, the polyvinyl alcohol-based resin layer 12 can exhibit an extremely excellent oxygen barrier property by recoupling the oxygen barrier property of the vapor deposited film.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminated film having a metal vapor deposition layer and excellent oxygen barrier properties.

Background Art

[0002] As is well known, a vapor deposition film having a metal vapor deposition layer is excellent in the barrier properties (barrier property) against various gases such as oxygen gas and water vapor (Patent Document 1).

[0003] However, although such a vapor deposition film having a metal vapor deposition layer is extremely excellent in water vapor barrier properties, it cannot be said to be sufficient in oxygen barrier properties.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, an object of the present invention is to provide a laminated film having a metal vapor deposition layer and excellent oxygen barrier properties.

Means for Solving the Problems

[0006] That is, the invention according to claim 1 is configured by laminating a stretched polyvinyl alcohol-based resin layer and a vapor deposition film having a metal vapor deposition layer , the polyvinyl alcohol-based resin layer is laminated on the extended base material film, and by extending the non-extended base material film coated with the polyvinyl alcohol-based resin, these base material films and the polyvinyl alcohol-based resin layer are extended in the same direction. and is an oxygen barrier laminated film characterized by that.

[0007] Next, the invention according to claim 2 is The metal vapor deposition layer is composed of an aluminum vapor deposition layer. an oxygen barrier laminated film according to claim 1, characterized by that.

[0008] Next, the invention described in claim 3 is as follows: The vapor deposition film is composed of a non-extended film as a vapor deposition base material and a metal vapor deposition layer laminated on this vapor deposition base material. The present invention is characterized in that 1 or 2 2. The oxygen barrier laminate film according to claim 1 . Effect of the Invention

[0012] As mentioned above, the vapor-deposited film having a metal vapor-deposited layer has excellent water vapor barrier properties. On the other hand, the polyvinyl alcohol-based resin layer has excellent oxygen barrier properties, and since this polyvinyl alcohol-based resin layer is stretched, its oxygen barrier properties are further improved, and therefore it complements the oxygen barrier properties of the vapor-deposited film and exhibits extremely excellent oxygen barrier properties. [Brief description of the drawings]

[0013]

Figure 1

Figure 2

[0014] Specific examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 is an exploded cross-sectional view illustrating a first example of an oxygen barrier laminate film of the present invention.

[0015] As can be seen from FIG. 1, the laminated film 10A is constructed by laminating two types of films that are bonded together with an adhesive layer 15.

[0016] Of the two types of films that make up this laminated film 10A, one film is composed of a base film 11, a polyvinyl alcohol-based resin layer 12, and a printing layer 13. This film is formed by first applying a polyvinyl alcohol-based resin to the base film 11 to form the polyvinyl alcohol-based resin layer 12 and then stretching it, thereby simultaneously stretching the base film 11 and the polyvinyl alcohol-based resin layer 12. For this reason, the base film 11 and the polyvinyl alcohol-based resin layer 12 are stretched in the same stretching direction and at the same stretching ratio. The printing layer 13 is formed by printing on the surface of the stretched polyvinyl alcohol-based resin layer 12.

[0017] The base film 11 may be any plastic film. For example, it can be a polyester film, a polyethylene film, a polypropylene film, a polystyrene film, a nylon film, a polycarbonate film, a polyacrylonitrile film, a polyimide film, etc.

[0018] Also, as the polyvinyl alcohol-based resin layer 12, in addition to the polyvinyl alcohol resin, its derivatives can be used. For example, a copolymer resin of ethylene and vinyl alcohol.

[0019] Also, of the two types of films that make up the film 10A, the other film is a vapor deposition film 14 formed by laminating a metal vapor deposition layer 14b on a vapor deposition base material 14a.

[0020] Any film can be used as the vapor deposition base material 14a. It may be a single-layer structure film or a multi-layer structure film.

[0021] As the single-layer film, for example, polyester film, polyethylene film, polypropylene film, polystyrene film, nylon film, polycarbonate film, polyacrylonitrile film, polyimide film, etc. can be used. It may be a stretched film, but an unstretched film can be preferably used. For example, it is an unstretched polypropylene film.

[0022] Also, as the multi-layer film, it is possible to use a film obtained by laminating the aforementioned single-layer films.

[0023] As the metal vapor deposition layer 14b, as a representative example, an aluminum vapor deposition layer can be cited. Of course, vapor deposition layers of other metals may also be used. For example, copper, silver, etc.

[0024] This metal vapor deposition layer 14b can be formed on the surface of the vapor deposition substrate 14a using a vacuum process such as a vacuum evaporation method, a sputtering method, or a plasma chemical vapor deposition method.

[0025] The polyvinyl alcohol-based resin layer 12 can be laminated, and the stretched base film 11 and the vapor deposition film 14 can be adhered by an adhesive layer 15. As the adhesive constituting this adhesive layer 15, a general-purpose adhesive for dry lamination can be used. Note that it is desirable to arrange the base film 11 so that the polyvinyl alcohol-based resin layer 12 faces the vapor deposition film 14, and it is desirable to arrange the vapor deposition film 14 so that its metal vapor deposition layer 14b faces the polyvinyl alcohol-based resin layer 12. The illustrated example is a film 10A in which each film is arranged and laminated so that the adhesive layer 15 contacts both the polyvinyl alcohol-based resin layer 12 and the metal vapor deposition layer 14b.

[0026] This film 10A has a polyvinyl alcohol-based resin layer 12 laminated on a vapor-deposited film 14. Moreover, since this polyvinyl alcohol-based resin layer 12 is stretched, the stretched polyvinyl alcohol-based resin layer 12 compensates for the lack of oxygen barrier properties of the vapor-deposited film 14. And because of this, while taking advantage of the high water vapor barrier properties of the vapor-deposited film 14, its oxygen barrier properties are greatly improved.

[0027] Next, FIG. 2 is an exploded cross-sectional explanatory view showing a second example of the oxygen barrier laminated film of the present invention.

[0028] This oxygen barrier film 10B is different from the first example in that a polyvinyl alcohol-based resin film 12' formed separately from the base film 11 is used as the polyvinyl alcohol-based resin layer.

[0029] The base film 11 is stretched, and the polyvinyl alcohol-based resin film 12' is also stretched. However, the stretching process of the base film 11 and the stretching process of the polyvinyl alcohol-based resin film 12' are also carried out separately and independently of each other. For this reason, the stretching direction of the base film 11 and the stretching direction of the polyvinyl alcohol-based resin film 12' can be different from each other. Also, the stretching ratio of the base film 11 and the stretching ratio of the polyvinyl alcohol-based resin film 12' can be different from each other. Note that the stretching direction and stretching ratio of the base film 11 and the stretching direction and stretching ratio of the polyvinyl alcohol-based resin film 12' can be made the same, but it is difficult to make them exactly the same.

[0030] These base film 11 and polyvinyl alcohol-based resin film 12' can be adhesively laminated with an adhesive layer 16. As the adhesive constituting the adhesive layer 16, a general-purpose adhesive for dry lamination can be used.

[0031] In addition, in other respects, the laminated film 10B according to the second example is the same as the laminated film 10A according to the first example.

Example

[0032] (Example 1) An unstretched polyethylene terephthalate film was used as the base film 11, and a polyvinyl alcohol resin was applied thereon to form a polyvinyl alcohol-based resin layer 12, and then stretched, so that the base film 11 and the polyvinyl alcohol-based resin layer 12 were stretched simultaneously and stretched.

[0033] Also, an unstretched polypropylene film (CPP) was used as the vapor deposition base material 14a, and aluminum was vacuum-deposited thereon to form a metal vapor deposition layer 14b.

[0034] Then, using a dry lamination adhesive, the polyvinyl alcohol-based resin layer 12 and the metal vapor deposition layer 14b were adhesively laminated so as to face each other, and a laminated film according to Example 1 was manufactured.

[0035] (Example 2) A biaxially stretched polyethylene terephthalate film was used as the base film 11. Also, as the polyvinyl alcohol-based resin layer, a separately formed and stretched polyvinyl alcohol resin film 12' was used independently of the base film 11. Then, using a dry lamination adhesive, these two films 11 and 12' were adhesively laminated to each other.

[0036] Also, the same vapor deposition film 14 as that in Example 1 was used. That is, an unstretched polypropylene film (CPP) was used as the base material 14a, and aluminum was vacuum-deposited thereon to form a metal vapor deposition layer 14b, thereby obtaining the vapor deposition film 14.

[0037] Then, using a dry lamination adhesive, the polyvinyl alcohol-based resin layer 12 and the metal vapor deposition layer 14b were adhesively laminated so as to face each other, and a laminated film according to Example 2 was manufactured.

[0038] (Comparative Example 1) Instead of the vapor deposition film 14, an unstretched polypropylene film (CPP) without a metal vapor deposition layer was used. Regarding other points, the laminated film of Comparative Example 1 was produced in the same manner as in Example 1.

[0039] (Comparative Example 2) A laminated film of Comparative Example 2 was produced in the same manner as in Example 1, except that a base film 11 without a polyvinyl alcohol resin layer 12 was used without applying a polyvinyl alcohol resin.

[0040] (Evaluation) Regarding the laminated films of Examples 1 to 2 and Comparative Examples 1 to 2, the oxygen permeability (cm 3 / (m 2 ·day·MPa)) was measured using an oxygen permeability measuring device (trade name: OXTRAN-2 / 20, manufactured by MOCON). The measurement results are shown in Table 1. In the table, "film adhesion" means that a polyvinyl alcohol resin film 12' manufactured separately from the base film 11 was adhered to the base film 11.

[0041]

Table 1

[0042] As can be seen from these results, in Comparative Example 1 which has a metal vapor deposition layer but no polyvinyl alcohol resin layer, its oxygen permeability is relatively high and it does not exhibit sufficient oxygen barrier properties.

[0043] On the other hand, in Examples 1 to 2 which have a polyvinyl alcohol resin layer stretched together with the metal vapor deposition layer, their oxygen permeability is kept low and they exhibit excellent oxygen barrier properties. Moreover, it does not depend on whether the polyvinyl alcohol resin layer is formed by applying a polyvinyl alcohol resin to the base film or by adhering a polyvinyl alcohol resin film 12' manufactured separately from the base film 11 to the base film 11.

[0044] In Comparative Example 2 which has a polyvinyl alcohol-based resin layer but no metal vapor deposition layer, since its oxygen transmission rate is the highest, it can also be understood that both the stretched polyvinyl alcohol-based resin layer and the metal vapor deposition layer are necessary to exhibit sufficient oxygen barrier properties. The invention described in the original claims is appended below. [1] An oxygen barrier laminated film characterized by being composed of a laminated polyvinyl alcohol-based resin layer and a vapor deposition film having a metal vapor deposition layer. [2] The oxygen barrier laminated film according to item 1, characterized in that the polyvinyl alcohol-based resin layer is laminated on the extended base material film. [3] The oxygen barrier laminated film according to item 2, characterized in that by extending the base material film coated with the polyvinyl alcohol-based resin, these base material films and the polyvinyl alcohol-based resin layer are extended in the same direction. [4] The oxygen barrier laminated film according to item 2, characterized in that the extended polyvinyl alcohol-based resin film and the extended base material film are laminated via an adhesive layer. [5] The oxygen barrier laminated film according to any one of items 1 to 4, characterized in that the metal vapor deposition layer is composed of an aluminum vapor deposition layer. [6] The oxygen barrier laminated film according to any one of items 1 to 5, characterized in that the vapor deposition film is composed of a non-extended film as a vapor deposition base material and a metal vapor deposition layer laminated on this vapor deposition base material.

Explanation of Symbols

[0045] 10A, 10B: Oxygen barrier laminated film 11: Substrate film 12: Polyvinyl alcohol-based resin layer 12’: Polyvinyl alcohol-based resin film 13: Printing layer 14: Vapor deposition film 14a: Vapor deposition substrate 14b: Metal vapor deposition layer 15: Adhesive layer 16: Adhesive layer

Claims

1. A laminated oxygen barrier film comprising a laminated structure of a stretched polyvinyl alcohol resin layer and a vapor deposition film having a metal vapor deposition layer, wherein the stretched base film has the polyvinyl alcohol resin layer laminated thereon, and the base film and the polyvinyl alcohol resin layer are stretched in the same direction by stretching an unstretched base film coated with a polyvinyl alcohol resin.

2. The oxygen barrier laminated film according to claim 1, wherein the metal vapor deposition layer is an aluminum vapor deposition layer.

3. The oxygen barrier laminated film according to claim 1 or 2, wherein the vapor deposition film is formed by laminating a metal vapor deposition layer on a non-stretched film as a vapor deposition substrate.

Images