JP2016074165A - Gas barrier laminated film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film capable of maintaining excellent gas barrier properties even if placed in a high humidity environment for a long period of time.SOLUTION: There is provided a method for producing a gas barrier laminated film having a layer comprising an organic layer and an inorganic layer on at least one surface of a plastic film, which comprises: a step of preparing the organic layer on at least one surface of the plastic film; a step of heat treating the organic layer prepared at a temperature less than the glass transition temperature of a polymer constituting the organic layer; and a step of preparing the inorganic layer on the organic layer subjected to the heat treatment. The heat treatment temperature preferably satisfies the relation, (Tg-20)≤Heat treatment temperature T≤(Tg-5) for the glass transition temperature Tg of the polymer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent gas barrier laminate film that is suitably used when high gas barrier properties are particularly required in the fields of solar cell-related members and electronic device-related members.

  In recent years, in solar cell-related members and electronic device-related members, it has been studied to use a light and flexible transparent plastic film as a substrate instead of a heavy and easily broken glass substrate. Further, when a plastic film is used for the substrate, a roll-to-roll production method can be applied, so that it can be expected to reduce the production cost of glass compared to the substrate.

  On the other hand, the plastic film has a problem that the gas barrier property is inferior to that of glass. On the plastic film, a vapor-deposited thin film layer of an inorganic oxide such as silicon oxide, aluminum oxide or magnesium oxide is used as a gas barrier layer. Discloses a laminated film obtained by laminating an appropriate gas barrier coating layer. However, these laminated films have a problem that the gas barrier performance is lowered when they are placed under high humidity for a long time, and not only have a high gas barrier property in order to be used as a solar cell related member or an electronic device related member. There is a need for a gas barrier film having weather resistance.

  In order to meet this demand, Patent Document 1 discloses a technique for providing a gas barrier laminated film having excellent durability by performing a heat treatment after laminating a gas barrier film in which an inorganic layer and an organic layer are laminated on at least one surface of a plastic film. Has been proposed. However, there is a problem that the heat treatment process itself performed after the lamination on the gas barrier laminate film in which the inorganic layer and the organic layer are laminated causes a decrease in gas barrier properties, and sufficient gas barrier performance cannot be achieved. On the other hand, Patent Document 2 proposes a technique for suppressing a decrease in gas barrier performance in the heat treatment process by using a plastic substrate having a high glass transition temperature, but the level is not sufficient. An improvement was desired.

JP 2005-271467 A JP 2005-246716 A

  When the present inventors examined, when the heat treatment was performed after laminating the organic layer and the inorganic layer on the plastic substrate as in the conventional method for producing a gas barrier film, the solvent remaining in the organic layer was volatilized. It was found that the adhesion between the organic layer and the inorganic layer was lowered. For this reason, when it was left for a long time under high humidity, the gas barrier property was lowered, and there was a problem in practicality.

  Therefore, in order to solve the above-described problems of the prior art, the present invention provides a gas barrier film capable of maintaining excellent gas barrier properties even when kept for a long time under high humidity. With the goal.

  As a result of studying methods and conditions that can volatilize the solvent remaining in the organic layer of the gas barrier film, the present inventor has demonstrated excellent gas barrier properties even when placed under high humidity for a long period of time. The inventors have found a method for producing a gas barrier film capable of maintaining the above, and have completed the present invention.

That is, the invention according to claim 1 is a method for producing a gas barrier laminate film having a layer including an organic layer and an inorganic layer on at least one surface on a plastic film,
Forming the organic layer on at least one surface of the plastic film;
Heat-treating the formed organic layer at a temperature lower than the glass transition temperature of the polymer constituting the organic layer;
Forming the inorganic layer on the heat-treated organic layer;
Is provided. The manufacturing method of the gas-barrier laminated | multilayer film characterized by including at least is provided.

Invention of Claim 2 performs the said heat processing on the conditions which satisfy | fill following formula (1) with respect to the glass transition temperature Tg of the said polymer, The manufacturing method of the gas barrier laminated film of Claim 1 characterized by the above-mentioned. Is to provide.
Formula (1) (Tg-20) <= Heat processing temperature T <= (Tg-5)

  Invention of Claim 3 provides the manufacturing method of the gas-barrier laminated | multilayer film of Claim 1 or 2 characterized by performing the process which heat-processes on pressure_reduction | reduced_pressure conditions.

  Invention of Claim 4 provides the manufacturing method of the gas-barrier laminated film in any one of Claim 1 to 3 whose said pressure reduction conditions are 100 Pa or less.

  The invention according to claim 5 provides a gas barrier laminate film produced by the production method according to any one of claims 1 to 4.

  The gas barrier laminate film produced by the production method of the present invention has high gas barrier properties, and can maintain excellent gas barrier properties even when placed under high humidity for a long period of time.

It is sectional drawing of an example of the gas barrier laminated film which concerns on one Embodiment of this invention.

  Hereinafter, the gas barrier laminate film of the present invention and the production method thereof will be described with reference to the drawings. The description of the constituent elements described below is made based on typical embodiments of the present invention, but the present invention is not limited to the following embodiments.

  FIG. 1 is a cross-sectional view of an example of a gas barrier laminate film in the present invention. The gas barrier laminated film 10 is provided with a gas barrier layer 2 having a function of blocking water and oxygen in the atmosphere on one surface of the base material layer 1.

  The gas barrier layer 2 in the present invention has a structure in which at least an organic layer 21 and an inorganic layer 22 are sequentially laminated. A gas barrier layer in which a plurality of organic layers and inorganic layers are alternately stacked is preferable. The number of organic layers and inorganic layers constituting the gas barrier layer is not particularly limited, but is preferably 2 to 20 layers, and more preferably 3 to 10 layers. The gas barrier layer may be provided on both surfaces of the plastic film.

  The base material layer 1 of the gas barrier laminate film 10 is made of a transparent plastic film. Examples of the transparent plastic film include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polyether sulfone (PES), polystyrene film, polyamide film, polychlorinated film. A vinyl film, a polycarbonate film, a polyacrylonitrile film, a polyimide film, a biodegradable plastic film such as polylactic acid, and the like are used.

  These transparent plastic films may be stretched or unstretched, but those having excellent mechanical strength and dimensional stability are preferred. In particular, polyethylene terephthalate stretched in the biaxial direction is preferably used from the viewpoints of heat resistance and dimensional stability. Further, the transparent plastic film may contain additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, and a lubricant. Further, in the transparent plastic film, the surface on the side where other layers are laminated may be subjected to corona treatment, low temperature plasma treatment, ion bombardment treatment, chemical treatment, solvent treatment, etc. in order to improve adhesion. .

  Although the thickness of the base material layer 1 made of these transparent plastic films is not particularly limited, suitability as a solar cell-related member or electronic device-related member, workability when other layers are laminated, etc. Is practically preferable in the range of 3 to 250 μm.

  The organic layer 21 of the gas barrier laminate film 10 is made of a polymer layer. Examples of the polymer include polyester, polyurethane, epoxy resin, phenol resin, polystyrene, phenoxy resin, and the like, and these may be used in combination of two or more.

  As a method for forming the organic layer 21, a normal coating method can be used. For example, a dipping method, a roll coat, a gravure coat, a reverse coat, a knife coat, a comma coat, a die coat, a Mayer bar coat, etc. can be used. For drying the solvent after coating, known drying methods such as hot air drying, hot roll drying and infrared drying can be used.

  The thickness of the organic layer 21 is preferably 0.05 to 3 μm. Here, when the thickness is less than 0.05 μm, it is difficult to form a uniform layer, and there is a possibility that sufficient protective functions and gas barrier properties may not be exhibited. On the other hand, when the thickness exceeds 3 μm, when the organic layer is laminated and formed, an internal stress due to curing shrinkage works excessively, and a crack may occur in the lower layer.

  The method for producing a gas barrier laminate film of the present invention includes a step of heat treatment at a temperature lower than the glass transition temperature of the polymer constituting the organic layer after forming the organic layer and before forming the inorganic layer on the organic layer. . By performing the heat treatment, the solvent remaining in the organic layer volatilizes, and it is possible to suppress a decrease in the adhesion between the organic layer and the inorganic layer in a high-humidity environment. As a result, a decrease in gas barrier properties is also suppressed. be able to.

  If the temperature of the heat treatment is equal to or higher than the glass transition temperature of the polymer constituting the organic layer, crystallization of the polymer constituting the organic layer proceeds, and defects such as cracks may occur when other layers are laminated. Therefore, when the glass transition temperature of the polymer is Tg, (Tg-5) to (Tg-20) are preferable. By setting the heat treatment temperature within the above temperature range, the solvent remaining in the organic layer can be efficiently volatilized, and thus the gas barrier performance can be maintained without lowering the adhesion between the organic layer and the inorganic layer.

  The heating time may be appropriately selected according to the kind of polymer and the heating temperature, but is usually 0.5 to 48 hours, preferably 0.5 to 12 hours.

  Although the heating method is not particularly limited, a method of storing in a temperature-controlled room, a method of blowing hot air, a method of irradiating infrared rays, a method of contacting a hot roll, and the like can be used. These methods may be performed in combination of two or more.

  The heating method is preferably performed under reduced pressure conditions. When the heat treatment is performed under reduced pressure conditions, the volatilization effect of the solvent increases, and the amount of solvent in the organic layer can be reduced efficiently. There is no particular limitation on the decompression condition, but heat treatment is performed in a vacuum chamber under a decompression condition of 100 Pa or less, and then an inorganic layer is formed under a decompression condition of 100 Pa or less without opening the vacuum chamber to the atmosphere. Implementation is preferable in terms of production efficiency.

  The inorganic layer 22 of the gas barrier laminate film 10 is a thin film layer made of a metal compound. For example, silicon, aluminum, magnesium, titanium, zinc, tin, nickel, and oxides and nitrides thereof are used. In particular, aluminum oxide and silicon oxide can be suitably used because they have good transparency and excellent gas barrier stability.

  There is no restriction | limiting in particular as a formation method of the inorganic layer 22, Chemical vapor deposition methods, such as physical vapor deposition methods, such as a vacuum evaporation method and sputtering method, and plasma CVD, can be used.

  The thickness of the inorganic layer 22 is preferably 0.005 to 1 μm. Here, if the thickness is less than 0.005 μm, a uniform deposited thin film layer may not be obtained, and the function as a gas barrier material cannot be sufficiently achieved. If the thickness exceeds 1 μm, it is difficult to maintain flexibility in the deposited thin film layer, and if an external stress such as bending or tension is applied, the deposited thin film layer may be cracked.

  In the gas barrier laminate film of the present invention, functional layers such as an easy adhesion layer and a print layer may be further laminated. Moreover, it can also be laminated | stacked with another film and used in the field | areas, such as a packaging of foodstuffs, daily necessities, and a pharmaceutical.

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

<Example 1>
A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 100 μm was prepared as the base material layer 1 and prepared by dissolving polyester (Tg: 90 ° C.) in methyl ethyl ketone (MEK) on one surface of the base material layer 1. A solution having a solid content of 30% was applied and dried to form an organic layer 21 having a thickness of 0.5 μm.
Next, the PET film on which the organic layer 21 was formed was placed in a thermostatic bath, and heat treatment was performed at a set temperature of 80 ° C. for 8 hours.
Next, the heat-treated PET film was placed in a vacuum chamber, a mixed gas of 5 sccm of hexamethyldisiloxane (HMDSO) / 100 sccm of oxygen was introduced between the electrodes, and a high frequency of 13.56 MHz was applied at 0.5 kW. The inorganic layer 22 made of silicon oxide having a thickness of 0.05 μm was formed on the surface of the organic layer 21. Thus, the gas barrier laminate film of Example 1 was produced.

<Example 2>
In the gas barrier laminate film of Example 1, the PET film on which the organic layer 21 was formed was placed in a thermostatic bath, subjected to heat treatment at a set temperature of 80 ° C. for 7.5 hours, and then further 100 Pa or less in a vacuum chamber. Under reduced pressure conditions, heat treatment was performed at 80 ° C. for 0.5 hours. Other conditions were the same as in Example 1. Thus, a gas barrier laminate film of Example 2 was produced.

<Example 3>
A gas barrier laminate film was produced in the same manner as in Example 1 except that the heat treatment was performed at 70 ° C. in Example 1.

<Example 4>
A gas barrier laminate film was produced in the same manner as in Example 1, except that the heat treatment was performed at 85 ° C. in Example 1.

<Comparative Example 1>
In the gas barrier laminate film of Example 1, after the formation of the organic layer 21, the inorganic layer 22 was laminated without performing heat treatment. Other conditions were the same as in Example 1. Thus, a gas barrier laminate film of Comparative Example 1 was produced.

<Comparative Example 2>
In the gas barrier laminate film of Example 1, the PET film on which the organic layer 21 was formed was placed in a thermostatic bath, and heat treatment was performed at a set temperature of 90 ° C. for 8 hours. Other conditions were the same as in Example 1. Thus, a gas barrier laminate film of Comparative Example 2 was produced.

<Comparison evaluation>
About the gas-barrier laminated films of Examples 1 to 4 and Comparative Examples 1 and 2, water vapor permeation in a 40 ° C.-90% RH atmosphere was measured with a water vapor permeability meter (MOCON PERMATRAN-W 3/31) manufactured by Modern Control. The degree (g / m 2 · 24 h) was measured. The measurement results are shown in Table 1.

  From Table 1, after forming the organic layer and before laminating the inorganic layer, it is confirmed that the water vapor permeability of the gas barrier laminate film is improved by performing the heat treatment at a temperature below the glass transition temperature of the polymer constituting the organic layer. It was done. In particular, it was confirmed that when the heat treatment was performed under reduced pressure conditions, the water vapor transmission rate of the gas barrier laminate film was further improved.

  The gas barrier laminate film of the present invention is suitable in the fields of solar cell related members and electronic device related members, particularly when it is necessary to maintain a high gas barrier property even when left for a long period of time under high humidity. Used.

DESCRIPTION OF SYMBOLS 1 ... Base material layer 2 ... Gas barrier layer 10 ... Gas barrier property laminated film 21 ... Organic layer 22 ... Inorganic layer

Claims (5)

A method for producing a gas barrier laminate film having a layer containing an organic layer and an inorganic layer on at least one surface on a plastic film,
Forming the organic layer on at least one surface of the plastic film;
Heat-treating the formed organic layer at a temperature lower than the glass transition temperature of the polymer constituting the organic layer;
Forming the inorganic layer on the heat-treated organic layer;
A method for producing a gas barrier laminate film, comprising: The method for producing a gas barrier laminate film according to claim 1, wherein the heat treatment is performed under a condition satisfying the following formula (1) with respect to the glass transition temperature Tg of the polymer.
Formula (1) (Tg-20) <= Heat processing temperature T <= (Tg-5)   The method for producing a gas barrier laminate film according to claim 1 or 2, wherein the heat treatment is performed under reduced pressure.   Invention of Claim 4 is a manufacturing method of the gas-barrier laminated film in any one of Claim 1 to 3 whose said pressure reduction conditions are 100 Pa or less.   A gas barrier laminate film produced by the production method according to claim 1.

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