JP2010143180A - Highly moisture-proof gas barrier film laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly moisture-proof gas barrier film which is excellent in gas barrier property, particularly, in moisture barrier property under high temperature and high humidity. <P>SOLUTION: The highly moisture-proof gas barrier film laminate includes; an inorganic deposition layer, and a gas barrier layer formed of a protective coat layer, which are successively laminated on one surface of a substrate of plastic material; and a moisture-proof layer provided on the other surface of the substrate. Particularly, the moisture-proof layer is a biaxially-drawn polyolefin film. The highly moisture-proof gas barrier film laminate further includes a print layer and/or a heat seal layer on the protective coat layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas barrier film laminate, and is a gas barrier film excellent in moisture resistance especially under high temperature and high humidity.

  In recent years, food and pharmaceutical packaging has been required to prevent the influence of oxygen, water vapor, and other gases that alter the contents in order to suppress the alteration of the contents and maintain their functions and properties. Gas barrier films that block (gas) have been used. In recent years, this gas barrier film has been used in non-food packaging such as electronic materials, liquid crystal display elements, solar cells, electromagnetic wave shields, touch panels, EL substrates, color filters, etc. The use for materials is being considered. Since the range of use and the period are greatly expanded for this industrial material application, physical property guarantees after storage for a certain period in a high temperature and high humidity environment are required as an accelerated test.

  Conventional gas barrier films mainly include metal foils made of metals such as aluminum, resin films such as polyvinyl alcohol and ethylene vinyl alcohol copolymers, polyvinylidene chloride and polyacrylonitrile, or plastic films coated with these resins. Has been used. However, metal foil and metal vapor-deposited film have excellent gas barrier properties, but the contents cannot be confirmed through the packaging material, metal detectors cannot be used for inspection, and they must be treated as non-combustible materials when discarded after use. There are problems such as unavoidable. Gas barrier resin films and films coated with them are highly temperature and humidity dependent and cannot maintain high gas barrier properties. Furthermore, vinylidene chloride, polyacrylonitrile, etc. may be a source of harmful substances when discarded or incinerated. There are some problems. In other words, it can be said that the gas barrier wrapping materials that are currently used mainly have various problems.

  As a method for solving these problems, a laminated structure in which a metal oxide sol is coated on a metal oxide vapor-deposited plastic film (see Patent Document 1) is disclosed. Moreover, it is necessary to maintain a higher barrier performance under high temperature and high humidity in a bag for highly water-absorbing contents such as a bath agent that cannot be replaced with aluminum foil, and improvement thereof is desired.

The patent literature is as follows.
Japanese Patent Laid-Open No. 7-164591

  An object of the present invention is to provide a gas barrier laminate excellent in moisture and heat resistance that does not cause deterioration in physical properties such as adhesion deterioration even after being stored for a certain period of time in a high-temperature and high-humidity environment and can continue high barrier properties. is there.

  That is, in Patent Document 1, an inorganic vapor deposition layer exists between the inside and the outside of the gas barrier laminate and has gas barrier performance, but the inorganic vapor deposition layer exists inside the base material, The interface between the base material and the inorganic vapor deposition layer is exposed to the outside through the base material. Accordingly, an object of the present invention is to provide a gas barrier laminate excellent in moisture and heat resistance, in which there is no gas barrier effect on the interface between the base material and the inorganic vapor-deposited layer, and physical properties such as adhesion reduction in the portion do not occur. .

  The present invention has been made to solve such problems, and the object of the present invention is to provide a gas barrier layer composed of an inorganic vapor deposition layer and a protective coating layer on one side of a substrate composed of a plastic material. The problem is solved by a highly moisture-proof gas barrier film laminate that is laminated and provided with a moisture-proof layer on the opposite surface of the substrate.

  According to a second aspect of the present invention, there is provided a highly moisture-proof gas barrier film laminate according to the first aspect, wherein a printed layer and / or a heat seal layer is provided on the protective coating layer.

  In claim 3, a plurality of films in which an inorganic vapor deposition layer and a gas barrier layer made of a protective coating layer are sequentially laminated on one side of a base material made of a plastic material are laminated so that the base material and the protective coating layer are in contact with each other. Solved by a highly moisture-proof gas barrier film laminate, wherein a printed layer and / or a heat seal layer is provided on a protective coating layer not in contact with the protective coating layer, and a moisture-proof layer is provided on a substrate not in contact with the protective coating layer .

  In Claim 4, the moisture-proof layer is a biaxially stretched polyolefin film, which is solved by the highly moisture-proof gas barrier film laminate according to any one of Claims 1 to 3.

  In Claim 5, the moisture-proof layer is a biaxially stretched polyester film, which is solved by the highly moisture-proof gas barrier film laminate according to any one of Claims 1 to 3.

  An object of the present invention is to provide a gas barrier laminate excellent in moist heat resistance that can maintain high barrier properties without deterioration of physical properties such as adhesion reduction even after being stored in a high temperature and high humidity environment for a certain period of time.

  The present invention will be described in more detail with reference to the drawings. 1, 2 and 3 are cross-sectional views illustrating the gas barrier film laminate of the present invention.

  FIG. 1 is a side sectional view of a packaging material according to an embodiment of the present invention, in which a base film (1), an inorganic vapor deposition layer (2), a protective coat layer (3), an adhesive layer (4), and a heat seal layer. (5) A moisture-proof layer (6) is sequentially laminated on the opposite surface of the substrate.

  FIG. 2 is a side sectional view of a packaging material according to an embodiment of the present invention, in which a gas barrier layer composed of a base film (1-a), an inorganic vapor deposition layer (2-a) and a protective coating layer (3-a) is provided. Two layers are laminated through the adhesive layer (4-a) (1-b, 2-b, 3-b, 4-b), the heat seal layer (5), and the moisture-proof layer (6) on the opposite side in turn. It is a laminated structure.

  FIG. 3 is a side sectional view of a packaging material according to an embodiment of the present invention, in which a base film (1), a plasma pretreatment (7), an inorganic vapor deposition layer (2), a protective coating layer (3), A moisture-proof layer (6) is sequentially laminated on the opposite surface.

  The base film described above is a transparent plastic material, and a transparent film is preferable in order to make use of the transparency of the deposited thin film layer. For example, polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films such as nylon-6, nylon 66, polyvinyl alcohol, polyvinyl chloride film, polycarbonate A film, a polyacrylonitrile film, a polyimide film, or the like is used, which may be either stretched or unstretched, and preferably has mechanical strength and dimensional stability. These are processed into a film and used. In particular, polyethylene terephthalate arbitrarily stretched in the biaxial direction is preferably used.

  The thickness of the base film is not particularly limited. However, considering the suitability as a packaging material and the workability in the case of laminating other layers, it is practically in the range of 3 to 200 μm, depending on the application. It is preferable to be set to ˜100 μm.

  In addition, various known additives and stabilizers such as an antistatic agent, an ultraviolet ray preventing agent, a plasticizer, a lubricant, and the like may be used on the surface of the base material. In order to improve the adhesion to the thin film, Corona treatment, low temperature plasma treatment, and ion bombardment treatment may be performed as pretreatment. In particular, in order to reinforce the adhesion between the plastic substrate and the inorganic oxide layer, it is effective to perform a pretreatment by reactive ion etching (RIE) using plasma on the surface. By performing this RIE treatment, chemical effects such as the generation of functional groups on the surface of plastic substrates using the generated radicals and ions, ion etching of the surface to remove impurities, etc., smoothing It is possible to obtain two physical effects such as By performing such surface treatment, a dense thin film of an inorganic oxide can be formed in the subsequent vapor deposition. As a result, the adhesion between the base material and the metal or inorganic oxide layer can be strengthened, which not only leads to improved gas barrier properties and prevention of cracks, but also does not cause delamination.

  In addition, an anchor coat layer can be provided between the plastic substrate and the inorganic oxide layer, and uniform deposition of the vapor deposition layer in the next step by smoothing the surface of the substrate film and adhesion can be improved.

  The inorganic vapor deposition layer is composed of oxides such as silicon, aluminum, titanium, zirconium, tin, and magnesium, nitrogen, fluoride units, or a composite thereof, and vacuum such as vacuum vapor deposition, sputtering, plasma vapor deposition, etc. Formed by the process. In particular, aluminum oxide is colorless and transparent, has high gas barrier properties, and can be used for a wide range of applications.

  In general, the thickness of the deposited thin film layer 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.

  By providing the protective coating layer on the vapor deposition film, the hard and brittle vapor deposition film can be protected and cracks due to rubbing and bending can be prevented.

  The protective coating layer is a coating layer having a gas barrier property, and uses a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof. It is formed. For example, a solution obtained by mixing a water-soluble polymer dissolved in an aqueous (water or water / alcohol mixed) solvent with a metal alkoxide directly or previously hydrolyzed is used as a solution. After coating this solution on the vapor deposition thin film layer which consists of a metal or a mineralized oxide, it heat-drys and forms. Each component contained in the coating agent will be described in more detail.

Examples of the water-soluble polymer used in the coating agent in the present invention include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, and sodium alginate. In particular, when polyvinyl alcohol (hereinafter abbreviated as PVA) is used for the coating agent of the present invention, the gas barrier property is most excellent, which is preferable. PVA here is generally obtained by saponifying polyvinyl acetate. As PVA, for example, complete PVA in which only several percent of acetic acid groups remain can be used from so-called partially saponified PVA in which several tens percent of acetic acid groups remain, and other types may be used. .

The metal alkoxide is a compound represented by a general formula, M (OR) _n (M: metal such as Si, Ti, Al, Zr, R: alkyl group such as CH ₃ , C ₂ H ₅ ). Specific examples include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], among which tetraethoxysilane and triisopropoxy. Aluminum is preferable because it is relatively stable in an aqueous solvent after hydrolysis.

  It is also possible to add known additives such as isocyanate compounds, silane coupling agents, or dispersants, stabilizers, viscosity modifiers, and colorants to the solution as long as the gas barrier properties are not impaired. is there.

  As a method for applying the coating agent, conventionally known methods such as a dipping method, a roll coating method, a screen printing method, a spray method, and a gravure printing method that are usually used can be used.

  The thickness of the protective coating layer varies depending on the optimum conditions depending on the type of coating agent, the processing machine and the processing conditions, and is not particularly limited. However, when the thickness after drying is 0.01 μm or less, a uniform coating film cannot be obtained and sufficient gas barrier properties may not be obtained. On the other hand, if the thickness exceeds 50 μm, cracks are likely to occur in the film, which may be a problem. It is preferably in the range of 0.01 to 50 μm, more preferably in the range of 0.1 to 10 μm.

  A printing layer can also be provided on the protective coating layer. The printed layer is formed for practical use as a packaging bag, etc., and various pigments are added to conventionally used ink binder resins such as urethane, acrylic, nitrocellulose, rubber and vinyl chloride. , A layer composed of an ink to which additives such as extender pigments, plasticizers, desiccants, stabilizers and the like are added, and characters, patterns, etc. are formed. As a forming method, for example, a known printing method such as an offset printing method, a gravure printing method, or a silk screen printing method, or a known coating method such as a roll coating, a knife edge coating, or a gravure coating can be used. The thickness may be 0.1 to 2.0 μm.

  Moreover, when using as a packaging material, it is preferable to form a heat seal layer in the side used as the innermost layer of a laminated body. The heat seal layer is used for an adhesive part when forming a bag-shaped package, for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid. Resins such as ester copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, and metal cross-linked products thereof are used. The thickness is determined according to the purpose, but is generally in the range of 15 to 200 μm. As a forming method, a film-like product made of the above resin is bonded by using an adhesive such as a two-component curable urethane resin, a method of laminating by a non-solvent laminate, and the resin is heated and melted to form a curtain. Any of the extrusion laminating method, the extrusion method, and the knee laminating method can be laminated by a known method.

  It is necessary to provide a highly moisture-proof layer on the opposite surface of the substrate.

  When stored in a high temperature and high humidity environment by providing a moisture barrier layer, it prevents water from entering due to humidity from the substrate side, and prevents deterioration of the gas barrier layer consisting of the deposited thin film layer and protective coating layer, resulting in high temperature and humidity. High barrier performance can be maintained for a long time even in an environment. In particular, when the inorganic vapor deposition layer of the present invention is an oxide film such as aluminum, magnesium, or silicon, the unoxidized metal present in a trace amount in the vapor deposition film has passed through a hydroxide or hydroxide by water from the outside such as humidity. It is easy to change into another compound, and the changed portion becomes pores of the barrier, and the entire gas barrier film is easily deteriorated. For this reason, the moisture-proof layer is a layer for protecting the gas barrier layer against water entering from the substrate side, and the barrier performance of the moisture-proof layer is far more than the effect expected from the improvement of the barrier performance in the laminated structure. High moisture proof effect can be obtained.

  A vapor-deposited layer may be formed by depositing an inorganic oxide having a high water vapor barrier property on the moisture-proof layer, or a moisture-proof layer may be formed by coating EVOH or vinylidene chloride. A moisture-proof film may be laminated and laminated. In particular, the method of laminating a moisture-proof film is simple and can stably exhibit high moisture resistance. In addition, a moisture-proof film can be freely selected depending on uses such as texture, transparency, and heat resistance. As a method of laminating the moisture-proof film, a known method such as a dry laminating method in which an adhesive such as a two-component curable urethane resin is bonded or an extrusion laminating method in which a heat-melted resin is extruded and bonded in a curtain shape is used. It can be laminated.

  The moisture-proof film is preferably a film having a high water vapor barrier property, such as polypropylene film, polyethylene film, polyolefin film such as polycycloolefin, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer. , Resins such as ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers and their metal cross-linked products, polyvinyl chloride (PVD), polyvinylidene chloride (PVDC), polyvinyl alcohol (PVA), etc. It is done. A composite multilayer film in which the material is formed by coextrusion may be used. Furthermore, those obtained by coating vinylidene chloride on these films or those obtained by evaporating aluminum to improve the barrier performance may be used. Among them, the olefin film has high versatility and is inexpensive and has a high moisture resistance of the film and is preferable as a moisture-proof layer.

  Furthermore, considering transparency, price, film strength, printability, moisture resistance, etc., a biaxially stretched polyolefin film represented by polyethylene / polypropylene is more preferable.

  Further, depending on the use of industrial materials such as optical films, the moisture-proof film may be required to have transparency and heat resistance. When transparency and heat resistance are required, a biaxially stretched polyester film such as a polyester film, polyethylene terephthalate (PET), or polyethylene naphthalate (PEN) is preferable.

  The thickness of the film is not particularly limited, but considering the suitability as a packaging material and the processability when laminating other layers, it is practically in the range of 3 to 200 μm, depending on the application 6 to 100 μm. It is preferable that

  If higher barrier performance is required depending on the application, it is possible to increase the barrier performance by laminating two or more base films in which gas barrier layers consisting of an inorganic vapor deposition layer and a protective coating layer are laminated in sequence. It is.

  The gas barrier laminate of the present invention will be further described with specific examples, but the present invention is not limited to these examples as long as it does not exceed the gist thereof.

<Example 1>
As the base material layer (1), a biaxially stretched polyester film (P60, manufactured by Toray Film Processing Co., Ltd.) having a thickness of 12 μm and one side corona-treated is used. A vapor deposition layer (2) made of aluminum was laminated. Furthermore, a protective coat layer (3) composed of a dried film having a thickness of 0.2 μm is applied by laminating the following protective coating solution on the vapor deposition layer (2) using a gravure coater, and a gas barrier layer is laminated. did. A two-component curable urethane adhesive was provided on the opposite surface of the substrate by a dry laminating method, and a biaxially stretched polypropylene having a thickness of 20 μm was laminated to form a moisture-proof layer. Next, polyethylene having a thickness of 30 μm was extruded onto the protective coating layer by an extrusion laminating method to obtain a gas barrier laminate of the present invention as a heat seal layer.
(Protective coating solution)
Hydrolysis solution (solution A) having a solid content of 3 wt% (in terms of SiO ₂ ), added with 89.6 g of hydrochloric acid (0.1N) to 10.4 g of tetraethoxysilane and stirred for 30 minutes for hydrolysis. A 3 wt% water / isopropyl alcohol solution of polyvinyl alcohol (water: isopropyl alcohol in a weight ratio of 90:10) (liquid B). A mixture of liquid A and liquid B at a mixing ratio (wt%) of 60/40.

<Example 2>
In Example 1, a gas barrier laminate of the present invention was obtained in the same manner as in Example 1 except that two gas barrier layers were provided and laminated by providing a two-component curable urethane adhesive by a dry laminating method.

<Comparative Example 1>
In Example 1, the same procedure as in Example 1 was used, except that only a biaxially stretched polyester film having a thickness of 12 μm and having one side corona-treated (P60 manufactured by Toray Film Processing Co., Ltd.) was used instead of the gas barrier layer An inventive gas barrier laminate was obtained.

<Comparative example 2>
In Example 1, a biaxially stretched polypropylene having a thickness of 20 μm, which is a moisture-proof layer, was laminated with a two-component curable urethane adhesive on the protective coating layer, not on the opposite surface of the substrate, by a dry lamination method. Next, a gas barrier laminate of the present invention was obtained in the same manner as in Example 1 except that a heat seal layer having a thickness of 30 μm was provided on polypropylene by extrusion lamination.

<Evaluation 1>
The water vapor permeability of the films obtained in Examples 1 and 2 and Comparative Example 1 was measured with a water vapor permeability measuring device (PERMATRAN 3/31 manufactured by Modern Control) in an atmosphere of 40 ° C. and 90% RH.

<Evaluation 2>
A 10 cm square four-side sealed bag was prepared using the films obtained in Examples 1 and 2 and Comparative Example, and 10 g of calcium chloride was filled as the contents. The bag was stored in an environment of 40 ° C. 90% RH and 60 ° C. 90% RH for 3 months, and the weight increase after storage was measured. Water vapor barrier per m ² from the weight increase, water vapor barrier (g / m ² · day) = (weight before storage−weight after storage (g)) / (pouch size (m ² ) · storage days (day)) It was calculated by the following formula.

  Table 1 shows the evaluation results. From Table 1, Examples 1 and 2 and Comparative Example 2 have high water vapor barrier properties by the Mocon method, and Comparative Example 1 has low barrier properties. The barrier property when stored for 3 months at 30 ° C and 90% RH is not different from the Mokon method, but the barrier property when stored in a high temperature and high humidity environment of 60 ° C and 90% RH is opposite to the base film. However, in Comparative Example 2, since the moisture-proof layer is between the gas barrier layer and the sealant layer, the deterioration of the barrier layer due to the ingress of water from the substrate side can be prevented. Without deterioration.

<Example 3>
A biaxially stretched polyester film (Toray Film Processing Co., Ltd., P60) having a thickness of 12 μm was used as the base material layer (1), and pretreatment was performed by reactive ion etching (RIE) using plasma. A vapor deposition layer (2) made of aluminum oxide having a thickness of 12 nm was laminated by a vacuum vapor deposition apparatus. Furthermore, the protective coat liquid (3) which consists of a dried coating film with a thickness of 0.2 μm obtained by applying and drying a protective coating solution on the vapor deposition layer (2) again by a gravure coater was laminated, and a gas barrier layer was laminated. A two-component curable urethane adhesive was provided on the opposite surface of the substrate by a dry laminating method, and a 50 μm thick polyester film was laminated to form a moisture-proof layer. Next, a two-component curable urethane adhesive was similarly provided on the protective coat layer by a dry laminating method, and a 50 μm thick polyester film was laminated to obtain a gas barrier laminate of the present invention.

<Comparative Example 3>
In Example 3, a gas barrier laminate of the present invention was obtained in the same manner except that a polyester film having a thickness of 50 um was laminated on the re-exterior of the protective coating layer instead of applying a moisture-proof layer to the opposite surface of the substrate. .

<Experiment 2>
The film obtained in Example 3 and Comparative Example 3 was measured for water vapor permeability by the Mocon method, and then held at 85 ° C. in an atmosphere of 85% for 1000 h to evaluate the appearance after the test. When the appearance after the test was the same as before the test, it was evaluated as “Good”.

  Table 2 shows the evaluation results. From Table 2, the initial water vapor barrier performance of both Example 3 and Comparative Example 3 is high. Since Example 3 has good hot water resistance and moisture resistance, the appearance after the test was also good, but in Comparative Example 3, the coating deteriorated and peeled off after the test, and the floating appeared visually. Even if Example 3 is used as a barrier film for industrial materials used for optical films, solar cells, etc., it can withstand the accelerated test environment required for those products and can maintain the barrier performance.

  Table 1 is as follows.

表２は以下の通り。

Table 2 is as follows.

It is a sectional side view which shows one Example of the layer structure of the highly moisture-proof gas barrier laminated body concerning this invention. It is a sectional side view which shows one Example different from FIG. 1 of the layer structure of the high moisture-proof gas barrier laminated body concerning this invention. It is a sectional side view which shows one Example different from FIG.1 and FIG.2 of the layer structure of the high moisture-proof gas barrier laminated body concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1-a, 1-b ... Base film 2, 2-a, 2-b ... Inorganic vapor deposition layer 3, 3-a, 3-b ... Protective coating layer 4, 4-a, 4-b ... Adhesion Agent layer 5 ... Heat seal layer 6 ... Moisture-proof layer 7 ... Plasma pretreatment layer

Claims (5)

  A highly moisture-proof gas barrier film laminate, wherein a gas barrier layer comprising an inorganic vapor deposition layer and a protective coating layer is sequentially laminated on one side of a substrate made of a plastic material, and a moisture-proof layer is provided on the opposite side of the substrate.   The high moisture-proof gas barrier film laminate according to claim 1, wherein a print layer and / or a heat seal layer is provided on the protective coat layer.   Laminate multiple layers of films with an inorganic vapor deposition layer and a gas barrier layer consisting of a protective coating layer on one side of a plastic material so that the substrate and protective coating layer are in contact with each other. A high moisture-proof gas barrier film laminate, wherein a print layer and / or a heat seal layer is provided on a coat layer, and a moisture-proof layer is provided on a substrate not in contact with the protective coat layer.   The highly moisture-proof gas barrier film laminate according to any one of claims 1 to 3, wherein the moisture-proof layer is a biaxially stretched polyolefin film.   The highly moisture-proof gas barrier film laminate according to any one of claims 1 to 3, wherein the moisture-proof layer is a biaxially stretched polyester film.

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