JP4604671B2 - Transparent barrier film - Google Patents

Description

  The present invention relates to a gas barrier material used in the packaging field of foods, pharmaceuticals, precision electronic components and the like.

  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 and humidity, as a gas barrier layer has been generally used.

  However, packaging materials that use metal foils such as aluminum are not affected by temperature and humidity and have excellent gas barrier properties, but have the disadvantage that they must be treated as non-combustible materials when discarded after use. There was a problem.

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

However, the drawback of the inorganic vapor-deposited film is the low bending resistance derived from inorganic substances. In order to overcome this problem, a technique for applying a barrier polymer such as PVA on the vapor deposition layer as a protective and oxygen barrier auxiliary coating has been established. This technology capable of complementing the drawbacks of the inorganic vapor deposition film also includes the disadvantage that the manufacturing process becomes complicated because the inorganic vapor deposition is performed in a vacuum while the protective coating is performed at normal pressure.
If the protective coating can be applied in a vacuum, it is possible to realize a coating that is not only inexpensive but also capable of protecting the inorganic vapor-deposited film during the vapor deposition process.

  The vapor deposition technique of a 1,3,5-triazine derivative is an effective means for forming an organic film in a vacuum as described in Patent Document 1. However, the 1,3,5-triazine derivative vapor-deposited film has strong crystallinity and cannot exhibit sufficient adhesion even if it is simply sublimated / formed on aluminum oxide.

The known literature is described below.
Special table 2002-518219 gazette Japanese Patent Laid-Open No. 2002-19011

  The present invention has been made to solve the above-mentioned problems, and is to provide an excellent gas barrier film by improving the adhesion between an aluminum oxide layer and a 1,3,5-triazine derivative vapor deposition layer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the invention according to claim 1 is characterized in that a co-deposition layer of aluminum oxide and a 1,3,5-triazine derivative is formed on at least one surface of a base material made of a plastic material. An inclined structure in which the co-deposited layer is an AlOx layer / AlOx-1,3,5-triazine derivative mixed layer / 1,3,5-triazine derivative layer from the side close to the substrate. It is a transparent barrier film characterized by having .

  In the present invention, aluminum oxide and a 1,3,5-triazine derivative are co-deposited on a plastic film, so that the aluminum oxide and the 1,3,5-triazine derivative are mixed and have good adhesion and high oxygen / Water vapor barrier performance is obtained. As a result, a film having high oxygen / water vapor barrier performance can be provided at low cost.

  Aluminum oxide has low flexibility, and when used as a barrier layer of a packaging film, it causes barrier deterioration in a subsequent process such as a printing process. For this reason, a protective layer is provided on aluminum oxide for practical use. However, it can be expected that this protective layer is applied in-line in a vapor deposition machine by co-evaporation of a 1,3,5-triazine derivative and an inexpensive and good barrier film is obtained.

  Embodiments of the present invention will be described below.

  FIG. 1 is a partial explanatory view showing in cross section an embodiment of the gas barrier film of the present invention. A structure in which a co-deposited layer 5 having an inclined structure of AlOx layer 2 / AlOx-1,3,5-triazine derivative mixed layer 3 / 1,3,5-triazine derivative layer 4 is formed on the surface of plastic substrate 1 It is. The co-deposited layer 5 may be formed on both sides of the base material or may be multilayered.

  In the present invention, aluminum oxide and a 1,3,5-triazine derivative are co-deposited on a plastic film, so that the aluminum oxide and the 1,3,5-triazine derivative are mixed and have good adhesion and high oxygen / Water vapor barrier performance is obtained. In particular, it is more effective to form the co-evaporated layer 5 having the gradient structure of the AlOx layer 2 / AlOx-1,3,5-triazine derivative mixed layer 3 / 1,3,5-triazine derivative layer 4. This is because a compatible part is formed.

  The above-described substrate 1 is a plastic material, and is preferably a transparent film substrate if possible in order to make use of the transparency of the deposited thin film layer. Examples of the substrate include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polycarbonate films, polyacrylonitrile films, polyimide films and the like. Can be mentioned. The substrate may be either stretched or unstretched, and preferably has mechanical strength and dimensional stability. Among these, a polyethylene terephthalate film or a polyamide film arbitrarily stretched in the biaxial direction is preferably used. Various known additives and stabilizers such as an antistatic agent, an anti-ultraviolet agent, a plasticizer, and a lubricant may be used on the surface of the substrate opposite to the surface on which the vapor deposition layer is provided.

The thickness of the substrate is not particularly limited, and a film obtained by laminating films having different properties other than a single film can be used in consideration of suitability as a packaging material. In consideration of workability in forming a primer layer, a vapor-deposited thin film layer made of an inorganic oxide, and a gas barrier coating layer, a range of 3 to 200 μm is preferable, and a range of 6 to 30 μm is particularly preferable.

  In general, the thickness of the aluminum oxide layer 2 is desirably in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved. Further, when the film thickness exceeds 300 nm, the thin film cannot be kept flexible, and there is a problem because the thin film may be cracked due to external factors such as bending and pulling after the film formation. More preferably, it exists in the range of 10-150 nm.

  There are various methods for forming an aluminum oxide layer on a plastic substrate, and the aluminum oxide layer can be formed by a normal vacuum deposition method. In addition, other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD) can also be used. However, considering productivity, the vacuum deposition method is the best at present. As a heating means of the vacuum evaporation method, it is preferable to use any one of an electron beam heating method, a resistance heating method, and an induction heating method, but the electron beam heating method should be used in consideration of the wide selection of evaporation materials. Is more preferable. Moreover, in order to improve the adhesiveness of a vapor deposition thin film layer and a base material, and the denseness of a vapor deposition thin film layer, it is also possible to vapor-deposit using a plasma assist method or an ion beam assist method.

  In general, the thickness of the 1,3,5-triazine derivative vapor deposition layer 4 is desirably in the range of 50 to 2000 nm, and the value is appropriately selected. However, if the film thickness is less than 50 nm, the flexibility may not be sufficient, and the function as the aluminum oxide protective layer may not be sufficiently achieved. Further, when the film thickness exceeds 2000 nm, a high film forming speed is required, and there is a problem in combination with aluminum oxide vapor deposition as in-line film forming. Considering productivity, it is more preferably in the range of 500 to 1000 nm.

  As a vacuum deposition method for forming the 1,3,5-triazine derivative deposition layer, any one of an electron beam heating method, a resistance heating method, and an induction heating method can be used as a heating means. In view of apparatus cost, controllability, etc., it is more preferable to use the resistance heating method. Moreover, in order to improve the adhesiveness of a vapor deposition thin film layer and a base material, and the denseness of a vapor deposition thin film layer, it is also possible to vapor-deposit using a plasma assist method or an ion beam assist method.

  The film thickness of the aluminum oxide-1,3,5-triazine derivative mixed layer 3 is generally desirably in the range of 10 to 1000 nm, and the value is appropriately selected. However, if the film thickness is less than 10 nm, the adhesion between the aluminum oxide-1,3,5-triazine derivatives may not be sufficient, and the function as a packaging material may not be sufficiently achieved. Further, when the film thickness exceeds 1000 nm, a high film forming speed is required, and there is a problem in combining with aluminum oxide vapor deposition as in-line film forming. Considering productivity, it is more preferably in the range of 100 to 500 nm.

  A printing layer, an intervening film, a sealant layer, and the like can be laminated on the co-deposition layer 5 to obtain a packaging material.

  The intervening film is provided in order to increase the bag breaking strength and puncture strength at the time of the bag-shaped packaging material, and is generally a biaxially stretched nylon film, a biaxially stretched polyethylene terephthalate film, in terms of mechanical strength and thermal stability, It is necessary to be one selected from among biaxially stretched polypropylene films. The thickness is determined according to the material and required quality, but is generally in the range of 10 to 30 μm.

  Furthermore, the sealant layer is provided as an adhesive layer when forming a bag-like package. For example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer and their metals A resin such as a cross-linked product is used. The thickness is determined according to the purpose, but is generally in the range of 15 to 200 μm.

  A printing layer, an intervening film, a sealant layer, and the like can be laminated on the opposite surface of the 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.

<Example 1>
Substrates were used on one side of a PET film having a thickness of 12 μm as a base material using aluminum oxide by a reactive vapor deposition method using electron beam heating and melamine as a 1,3,5-triazine derivative by a resistance heating method. A barrier film having an inclined structure such that AlOx layer: 10 nm / AlOx-1,3,5-triazine derivative mixed layer: 200 nm / 1,3,5-triazine derivative layer: 1000 nm was prepared from the side close to the material.

<Example 2>
Implementation was performed except that the co-deposited layer had an inclined structure in which the thickness of the AlOx layer was 10 nm / AlOx-1,3,5-triazine derivative mixed layer: 100 nm / 1,3,5-triazine derivative layer: 500 nm. A barrier film was produced in the same manner as in Example 1.

<Comparative Example 1>
A barrier film was produced in the same manner as in Example 1 except that the 1,3,5-triazine derivative was not vapor-deposited and the AlOx layer had a structure of only 10 nm.

<Comparative Example 2>
A barrier is formed in the same manner as in Example 1 except that there is no AlOx-1,3,5-triazine derivative mixed layer and the AlOx layer is 10 nm / 1,3,5-triazine derivative layer: 1000 nm. A film was prepared.

  Furthermore, polyurethane-based ink was applied by a gravure method to prepare the above-mentioned deposited film / ink sample.

<Evaluation>
Adhesiveness of aluminum oxide / 1,3,5-triazine derivative:
Evaluated by a cross-cut test specified in JIS K5400 8.5.3.
Oxygen permeability: The film after printing was measured in an atmosphere of 30 ° C.-70% RH using an oxygen permeability measuring device (MOCON OXTRAN) manufactured by Modern Control.
The results are shown in Table 1.

結果は、酸素透過度が実施例１では１．８（ｃｃ／ｍ²・ｄａｙ・ａｔｍ）、実施例２では２．１、比較例１では１３、比較例２では５．２、となった。また密着性は、実施例１、２ともに全く剥離せず、比較例１ではクロスカット部の大部分が剥離し、比較例２も
同様にクロスカットの大部分が剥離した。本発明のバリアフィルムは比較例に比し、上記のように酸素バリア性、密着性共に優れている結果であった。

As a result, the oxygen permeability was 1.8 (cc / m ² · day · atm) in Example 1, 2.1 in Example 2, 13 in Comparative Example 1, and 5.2 in Comparative Example 2. . Also, the adhesiveness was not peeled off at all in Examples 1 and 2. In Comparative Example 1, most of the crosscut portion was peeled off, and in Comparative Example 2, the majority of the crosscut was peeled off as well. The barrier film of the present invention was superior in both oxygen barrier properties and adhesiveness as described above compared to the comparative example.

It is partial explanatory drawing which shows the example of embodiment of the gas barrier film of this invention in a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic base material 2 ... Aluminum oxide vapor deposition layer 3 ... Aluminum oxide 1,3,5-triazine derivative mixed layer 4 ... 1,3,5-triazine derivative vapor deposition layer 5 ... Co-deposition layer

Claims (1)

A co-deposited layer of aluminum oxide and a 1,3,5-triazine derivative is laminated at a thickness of 50 to 3000 nm on at least one surface of a base material made of a plastic material. A transparent barrier film having an inclined structure that becomes an AlOx layer / AlOx-1,3,5-triazine derivative mixed layer / 1,3,5-triazine derivative layer .

Images