JP5521360B2 - Method for producing gas barrier film - Google Patents

Description

  The present invention relates to a solar cell backsheet, a gas barrier film used in the packaging field of foods, pharmaceuticals, and the like, a manufacturing method thereof, and a manufacturing apparatus.

  The solar cell protection sheet is placed on the back side of the solar cell to prevent the deterioration of the patterned silicon thin film, which is the electromotive part of the solar cell module, due to humidity. Therefore, durability performance that does not deteriorate the gas barrier performance even when used under severe conditions such as the above is required.

  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 polymer film, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyacrylonitrile (Polyvinyl, which are relatively excellent in gas barrier performance among polymers, are used. PAN) and the like, 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, when the boil treatment or retort treatment under high temperature and high pressure conditions is performed, the gas barrier performance is reduced. Often the performance is significantly degraded. 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). Can't get.

  In addition, since PVDC and PAN have a high risk of generation of 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. As a result, the gas barrier performance had to be secured. However, since the metal foil is opaque, it is difficult to identify the contents through the packaging material, and the contents cannot be inspected by a metal detector and cannot be heat-treated in a microwave oven.

A gas barrier package having an inorganic oxide thin film layer on a polymer film is also known.
However, when these packaging bodies are exposed to harsh conditions such as outdoors for a long time, there is a problem that delamination occurs between the polymer film and the inorganic oxide thin film layer and the function as the packaging body is impaired. In order to obtain a highly durable gas barrier package that is used outdoors, etc., diligence is required.

  As one of means for imparting durability, attempts have been conventionally made to provide a base layer by a coating method in an atmospheric pressure environment. However, this method increases the number of processes and thus cannot be said to have high production efficiency.

As a method for obtaining high gas barrier performance (for example, 1 cc / m ² · day · atm or less), attempts have been made to provide an overcoat layer by a coating method on an inorganic oxide layer. However, this method increases the number of processes, so it cannot be said that the production efficiency is high.

JP 2008-62498 A JP 2008-36914 A JP-A-10-296929

  The present invention has been made to solve the above-mentioned problems, and improves the adhesion strength of an inorganic oxide vapor deposition layer, which has been insufficient with conventional vapor deposition methods, and provides a gas barrier film capable of obtaining high gas barrier performance, and the gas barrier An object of the present invention is to provide a manufacturing method and a manufacturing apparatus capable of manufacturing a film with high production efficiency.

Invention of Claim 1 is a polymer film used as a base material, Comprising: On the single side | surface or both surfaces of the said polymer film whose surface centerline average roughness (Ra) is the range of 0.5-1.5 nm. A base layer forming step of forming a base layer having a center line average roughness (Ra) below the polymer film, and a first inorganic oxide vapor deposition layer forming step of forming an inorganic oxide vapor deposition layer on the base layer An intermediate layer forming step of forming an intermediate layer having a center line average roughness (Ra) below the polymer film on the first inorganic oxide vapor deposited layer; and an inorganic oxide vapor deposited layer on the intermediate layer. a second inorganic oxide manufacturing process of Ruga scan barrier film having a vapor deposition layer forming step of forming,
The method for producing a gas barrier film, wherein the underlayer and the intermediate layer are formed by a plasma CVD method using a mixed gas composed of oxygen and hexamethyldisiloxane .
According to the second aspect of the present invention, all of the underlayer forming step, the first inorganic oxide vapor deposition layer forming step, the intermediate layer forming step, and the second inorganic oxide vapor deposition layer forming step are performed in one apparatus. which is a method for producing gas barrier film according to claim 1, wherein.

  ADVANTAGE OF THE INVENTION According to this invention, the gas barrier film whose barrier property is higher than before which improved the adhesiveness of a polymer film and an inorganic oxide vapor deposition layer can be provided with high production efficiency.

  As an action to suppress the deterioration of adhesion, a fresh substrate is formed by covering a layer that causes a decrease in adhesion strength, such as a weak bond layer (Weak Boundary Layer (WBL)) or a hydrolysis layer in the case of PET. It is considered that a surface is provided and adhesion with the inorganic oxide vapor deposition layer is improved, and at the same time, an interface that does not cause water resistance deterioration is formed.

  As an effect of improving the barrier property, it is possible to prevent the growth of defects generated during the formation of the first inorganic oxide deposition layer of the first layer by laminating the intermediate layer, or to deposit the first inorganic oxide of the first layer. It is thought that it becomes possible by forming the second inorganic oxide vapor deposition layer of the second layer on the fresh surface by adjusting the outermost surface of the layer.

  As an effect of realizing high productivity, the formation method of the underlayer and intermediate layer by the coating method under the atmospheric pressure environment used in the past requires changing the manufacturing equipment each time, but all processes are performed. It is considered that this is possible by reducing the indirect time and generating a loss due to contamination by performing a single device under a reduced pressure environment.

It is explanatory drawing of the cross section of the gas barrier film in one Embodiment of this invention. It is explanatory drawing of the gas barrier film manufacturing apparatus in one Embodiment of this invention. It is explanatory drawing of the gas barrier film manufacturing apparatus in one Embodiment of this invention. It is the table | surface which showed the comparison of the gas barrier property of the gas barrier film in this invention. It is the table | surface which showed the surface smoothness of the base layer and intermediate | middle layer in this invention.

  Embodiments of the present invention will be described below.

  FIG. 1 is a cross-sectional view illustrating a gas barrier film in one embodiment of the present invention. A base layer 2 formed by a plasma CVD method on a polymer film 1 serving as a base material, a first inorganic oxide deposition layer 3 on the base layer 2, and a plasma CVD on the first inorganic oxide deposition layer 3 The intermediate layer 4 is formed by the method, and the second inorganic oxide vapor deposition layer 5 is formed on the intermediate layer 4. Even if it forms on both surfaces of a base material, you may make it a multilayer, or you may make it the structure according to front and back.

  The polymer film 1 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. The use of a transparent film is preferable because it is suitable for mass production. Further, the thickness is not particularly limited, and in view of workability when forming a gas barrier film, a range of 12 to 250 μm is preferable in practice. Moreover, it is preferable to use the thing of the range whose centerline average roughness (Ra) of the surface of the polymer film 1 is 0.5-1.5 nm.

  The thickness of the underlayer 2 formed by the plasma CVD method on the polymer film 1 and the intermediate layer 4 formed by the plasma CVD method on the first inorganic oxide vapor deposition layer 3 is generally 20 to 100 nm. It is desirable that the value be appropriately selected. However, if the thickness is less than 20 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and sufficient smoothness may not be obtained. When the film thickness exceeds 100 nm, the film cannot retain flexibility, and there is a possibility that the film may crack due to external factors such as bending and pulling after film formation. Moreover, the surface smoothness may be lost by making the film thickness too thick. More preferably, it exists in the range of 20-40 nm. In addition, the smoothness of the underlayer 2 and the intermediate layer 4 is preferably equal to or higher than that of the polymer film 1. In particular, the center line average roughness (Ra) of the underlayer 2 and the intermediate layer 4 is preferably equal to or smaller than that of the polymer film 1. Thereby, adhesiveness with an inorganic oxide vapor deposition layer improves.

  When forming the underlayer 2 on the polymer film 1, it is particularly effective to use the plasma CVD method. By using the plasma CVD method, it is possible to fill in unevenness and defects existing in the base material from the beginning, and improve adhesion in the formation of an inorganic oxide vapor deposition layer to be performed later, and defects generated during the formation Can be suppressed, gas barrier performance can be improved, and delamination does not occur.

  When the intermediate layer 4 is formed on the first inorganic oxide vapor deposition layer 3, it is effective to use a plasma CVD method. By using the plasma CVD method, it is possible to fill the irregularities present on the outermost surface of the first inorganic oxide vapor deposition layer 3 and the defects generated when the first inorganic oxide vapor deposition layer 3 is formed. The second inorganic oxide vapor deposition layer 5 formed on the intermediate layer 4 can be formed again on the fresh surface, and the second inorganic oxide vapor deposition layer 5 is formed without forming the intermediate layer 4. Compared with the case, the gas barrier performance of the 2nd inorganic oxide vapor deposition layer 5 can be improved significantly.

  When the base layer 2 is formed on the polymer film 1 and when the intermediate layer 4 is formed on the first inorganic oxide vapor deposition layer 3 by the plasma CVD method, the gas species for exciting the plasma is argon. , Nitrogen, helium, oxygen, carbon dioxide, hydrogen, ammonia, ozone, tetraethylsiloxane, hexamethyldisiloxane, tetramethylcyclotetrasiloxane, hexamethyldisilazane, triethylsilane, trimethylsilane, monosilane, disilane Alternatively, or a mixed gas thereof may be used. However, when argon, nitrogen, helium, oxygen, carbon dioxide, hydrogen, ammonia, or ozone is used alone, the base layer is not formed and only surface treatment with plasma is performed. Different gases may be used when the underlayer 2 is formed on the polymer film 1 and when the intermediate layer 4 is formed on the first inorganic oxide deposition layer 3.

  There are various methods for forming the first inorganic oxide vapor-deposited layer 3 and the second inorganic oxide vapor-deposited layer 5, and they can be formed by a normal vacuum vapor deposition method. In addition, other forming methods such as sputtering, ion plating, and plasma vapor phase synthesis (CVD) can 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 in consideration of the wide selection of the evaporation material, the electron beam heating method is used. More preferably, it is used. Moreover, in order to improve the adhesiveness and denseness of an inorganic oxide vapor deposition layer and a base material, it is also possible to vapor-deposit using a plasma assist method or an ion beam assist method. Different methods may be used when the inorganic oxide vapor deposition layer 3 is formed and when the inorganic oxide vapor deposition layer 5 is formed.

  The underlayer 2 formed on the polymer film 1 by plasma CVD, the first inorganic oxide vapor deposition layer 3 on the underlayer 2, and the first inorganic oxide vapor deposition layer 3 formed on the polymer film 1 by plasma CVD. When forming the second inorganic oxide vapor deposition layer 5 on the intermediate layer 4 and the intermediate layer 4, all steps are performed under a reduced pressure environment, so that impurities are unlikely to cross each other and are suitable for a film forming environment. It becomes easy to maintain.

  The underlayer 2 formed on the polymer film 1 by plasma CVD, the first inorganic oxide vapor deposition layer 3 on the underlayer 2, and the first inorganic oxide vapor deposition layer 3 formed on the polymer film 1 by plasma CVD. When forming the second inorganic oxide vapor deposition layer 5 on the intermediate layer 4 and the intermediate layer 4, all the steps are performed in-line, so that the steps can be shortened and an inexpensive film can be provided.

  Furthermore, the gas barrier film in the present invention may be provided with other functional layers. For example, a hard coat layer or a conductive film may be formed on the outermost surface.

  FIG. 2 is an explanatory view of a gas barrier film manufacturing apparatus in one embodiment of the present invention. While the polymer film 1 moves on the roll, each layer is formed by the base layer forming means 6, the inorganic oxide vapor deposition layer forming means 7, the intermediate layer forming means 8, and the inorganic oxide vapor deposition layer forming means 7. The present invention is not limited to the apparatus shown in FIG. Either a winding / unwinding type or a batch type may be used. Further, as shown in FIG. 3, the polymer film 1 is moved on one roll, and the base layer forming means 6, the inorganic oxide vapor deposition layer forming means 7, the intermediate layer forming means 8, the inorganic oxide vapor deposition layer forming means. 7 may be used to form each layer. In that case, it is possible to reduce the size of the apparatus, shorten the process, and reduce the cost.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to the following example.

<Example>
A base layer is formed on one surface of a polyethylene terephthalate film having a thickness of 100 μm by plasma CVD, a first inorganic oxide vapor deposition layer is provided thereon, an intermediate layer is formed thereon, and then a second inorganic oxide vapor deposition layer. Formed. At this time, a 13.56 MHz RF power source for forming the underlayer and the intermediate layer was formed by plasma CVD, and a mixed gas of oxygen / hexamethyldisiloxane was used as a gas species for exciting the plasma. . In this case, the treatment pressure was 20 Pa and the thickness was 30 nm. A gas barrier film was formed by forming a silicon oxide film with a thickness of 40 nm by vacuum deposition using an electron beam heating method in common for forming the inorganic oxide vapor deposition layer twice.

<Comparative Example 1>
A first inorganic oxide vapor deposition layer was formed on one side of a 100 μm thick polyethylene terephthalate film to obtain a gas barrier film. The other conditions are the same as in Example 1.

<Comparative example 2>
A base layer was formed by plasma CVD on one side of a 100 μm thick polyethylene terephthalate film, and a first inorganic oxide vapor deposition layer was formed thereon to form a gas barrier film. The other conditions are the same as in Example 1.

<Comparative Example 3>
A base layer is formed on one side of a 100 μm-thick polyethylene terephthalate film by plasma CVD, a first inorganic oxide vapor deposition layer is provided thereon, and an intermediate layer is not formed thereon, and a second inorganic oxide vapor deposition layer is formed. Formed. The other conditions are the same as in Example 1.

<Evaluation 1 Gas barrier properties>
The gas barrier property of the product of the present invention was measured using an oxygen permeability measuring device (MOCON OXTRAN 2/21 manufactured by Modern Control) and a water vapor permeability measuring device (MOCON PERMATRAN 3/21 40 ° C. 90% RH atmosphere manufactured by Modern Control). . As a result, the gas barrier properties were as follows: Example> Comparative Example 3≈Comparative Example 2> Comparative Example 1. The result is shown in FIG.

<Evaluation 2 Adhesion>
The adhesion of the product of the present invention was measured using an underwater tensile tester. As a result, the deposited film formed by the method shown in the Examples had stronger adhesion than the deposited film formed by the method shown in Comparative Examples 1 to 3.

<Evaluation 3 Durability>
In order to measure the durability of the product of the present invention, the adhesion after a 48-hour pre-shear cooker test was measured using an underwater tensile tester. As a result, the deposited film formed by the method shown in the examples did not have a decrease in adhesion, and peeling of the film surface was not confirmed.

<Evaluation 4 Surface smoothness>
The results of measuring the centerline average roughness (Ra) of the surface of the 100 μm-thick polyethylene terephthalate film, the underlayer and the intermediate layer used in the product of the present invention using a scanning probe microscope (NANOSCOPEIIIA manufactured by Nihon Beco) As shown in FIG.

  As the industrial applicability of the gas barrier film in the present invention, a back barrier sheet for a solar cell, a gas barrier film used in the packaging field of foods, pharmaceuticals and the like can be considered.

DESCRIPTION OF SYMBOLS 1 ... Polymer film 2 ... Underlayer formed by plasma CVD method 3 ... First inorganic oxide vapor deposition layer 4 ... Intermediate layer formed by plasma CVD method 5 ... Second inorganic oxide vapor deposition layer 6 ... Underlayer formation Means 7 ... Inorganic oxide vapor deposition layer film forming means 8 ... Intermediate layer forming means

Claims (2)

A polymer film serving as a base material, the center line of the surface of the polymer film having a center line average roughness (Ra) in the range of 0.5 to 1.5 nm on one or both surfaces of the polymer film or less. An underlayer forming step for forming an underlayer having an average roughness (Ra), a first inorganic oxide vapor deposition layer forming step for forming an inorganic oxide vapor deposition layer on the underlayer, and the first inorganic oxide vapor deposition An intermediate layer forming step of forming an intermediate layer having a center line average roughness (Ra) below the polymer film on the layer, and a second inorganic oxide vapor deposited layer forming an inorganic oxide vapor deposited layer on the intermediate layer a method of manufacturing a Ruga scan barrier film having a a forming step,
The method for producing a gas barrier film, wherein the underlayer and the intermediate layer are formed by a plasma CVD method using a mixed gas composed of oxygen and hexamethyldisiloxane. The underlying layer forming step, according to claim 1 in which the first inorganic oxide vapor deposition layer forming process, all of the intermediate layer forming step and the second inorganic oxide vapor deposition layer forming process is characterized in that is performed within one apparatus Of manufacturing a gas barrier film.

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