JP2008290406A - Gas barrier film and gas barrier layered body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas barrier film which has satisfactory adhesiveness with a thermoplastic resin even when laminating the molten thermoplastic resin by extrusion directly on a gas barrier coated film layer of the gas barrier film, and to provide a gas barrier layered body made by laminating a thermoplastic resin layer. <P>SOLUTION: The gas barrier film is a layered film made by providing the gas barrier coated film layer composed of a water-soluble polymer and an inorganic compound to at least one side surface of a plastic film base material 1, wherein at least the surface of the gas barrier coated film layer 3 is a surface-treated surface 4 on which the functional group ratio D=(C-OH/C-C) of carbon-hydrocarbon group bond (C-OH) to carbon-carbon bond (C-C) of the water-soluble polymer lies in the range of 0.35 to 0.77 and the contact angle to water lies in the range of 28 to 40°. The gas barrier layered body is made by laminating the thermoplastic resin layer 5 on the gas barrier coated film layer 3 across the surface-treated surface 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas barrier film made of a plastic substrate, and a gas barrier laminate having strong interlayer adhesion when the gas barrier film and a thermoplastic resin are melt-extruded and laminated.

  A multilayer laminated film or laminate used for packaging or the like is used by attaching a plastic film, a metal foil, paper or the like according to the required physical properties. For example, saturated polyester (polyethylene terephthalate) film has excellent mechanical properties, dimensional stability, toughness, etc., and is therefore used as a base material for laminated films. A foil or an inorganic vapor-deposited film is used, and a heat-melting adhesive heat-sealable resin layer is laminated to provide heat-sealability as a packaging material.

  Examples of a method for producing such a laminated film include a dry laminating method, a wet laminating method, a melt extrusion laminating method, and the like, but an extrusion laminating method that is advantageous in terms of production cost and production efficiency is widely used. .

  The extrusion laminating method is generally used when a laminated film is produced by laminating and laminating a resin such as polyethylene, polypropylene, and an ethylene copolymer on a plastic film substrate. However, even if these resins are heated and melted and extruded onto a plastic substrate surface such as a saturated polyester (polyethylene terephthalate) film, the adhesiveness is poor. Therefore, an anchor coat (AC) agent is usually applied to the plastic substrate surface in advance. After applying to form an anchor coat (AC) layer, the molten resin is extruded onto the anchor coat layer and laminated.

  However, AC agents generally use an organic solvent such as ethyl acetate or toluene as a diluting solution. Therefore, compliance with the regulations of the Fire Service Act, deterioration of the work environment, and production by using relatively expensive coating agents. There are problems such as increased cost and odor due to residual organic solvent in the final product. Furthermore, when using a film base as an intermediate layer of a laminated film, it is necessary to apply an AC agent on both sides of the film base, and the equipment for applying to both sides of the film base is special. In order to produce a laminated film or laminate by coating on both sides of the film substrate with the above equipment, there is a problem that the number of steps must be increased.

  Until now, as a measure for improving the adhesion strength in the laminated laminate, many methods without using an AC agent using an organic solution for dilution as described above have been tried. As one of the methods using an AC agent that does not use an organic solution for dilution, an ethylene-methacrylic acid copolymer obtained by copolymerizing an acid component is used as an AC agent that does not use an organic solution, so that the aluminum foil is firmly bonded. Alternatively, a technique for improving adhesion strength by extruding a resin obtained by graft-modifying an unsaturated carboxylic acid to a polypropylene resin as an AC agent that does not use an organic solution on a deposited plastic film substrate is widely known. Yes. However, since these are limited in the base material and resin used for the laminated laminate, they cannot be applied to a combination in a laminated laminate of a general plastic substrate and a resin such as polyethylene resin.

Therefore, recently, as shown in Patent Documents 1 to 3, a method of obtaining good adhesion with a substrate without an AC agent by performing ozone treatment on the molten resin surface during extrusion lamination has been disclosed. . In this method, ozone needs to be sprayed onto the resin. However, since ozone has a bad odor and is toxic, consideration for safety is necessary. Furthermore, there is a problem that it is difficult to confirm whether the ozone treatment is performed uniformly.

  In order to solve the above-described problems, Patent Document 4 discloses a method in which a printing layer is provided on a base material and an extrusion lamination is performed after a surface treatment with ultraviolet rays is performed on the printing layer. . However, in this method, even if the printing layer laminating step and the surface treatment step are performed in-line, there is a problem that the manufacturing process and the cost only increase in the configuration that does not require the printing layer.

  Furthermore, in recent years, a transparent gas barrier film that is frequently used as a packaging film has a gas barrier layer laminated on one side or both sides of the film. Also when it makes it express, it has the same problem as the above-mentioned base material.

Below, the prior technical literature relevant to this invention is described.
Japanese Patent No. 2895917 Japanese Patent No. 3385663 Patent 3716006 JP 2000-238195 A

  The present invention has been made in order to solve the above-described problems. A thermoplastic resin such as polyethylene, polypropylene, and an ethylene copolymer is laminated on a gas barrier film made of a plastic film substrate by extrusion lamination. When producing a gas barrier laminate by laminating, without using or applying an anchor coat (AC) agent or adhesive using an organic solvent for dilution on the film substrate surface side, extrusion lamination Laminated thermoplastic resin is extruded and laminated directly to the gas barrier coating layer of the gas barrier film as the film base without applying ozone treatment to the molten thermoplastic resin that is sometimes extruded to the film base surface side. Provides a gas barrier film with good adhesion between the film substrate and resin. In addition, the present invention provides a gas barrier laminate in which a thermoplastic resin is extruded and laminated on the gas barrier film with little decrease in adhesion between the film substrate and the resin even when heat sterilization treatment such as boil treatment or retort is performed. There is.

The invention according to claim 1 of the present invention is a laminated film in which a gas barrier coating layer comprising a water-soluble polymer and an inorganic compound is provided on at least one surface of a plastic film substrate, wherein at least the surface of the gas barrier coating layer Is a surface-treated surface 4 that satisfies both of the following surface states (1) and (2).
(1) When the surface-treated surface 4 on the surface of the gas barrier coating layer is measured using X-ray photoelectron spectroscopy (XPS), the carbon-carbon bond (CC) and the carbon-hydroxyl bond (C -OH) has a functional group ratio D = (C-OH / C-C) of 0.35 or more and 0.77 or less.
(2) The contact angle with respect to water of the surface treatment surface 4 of the gas barrier coating layer surface is 28 degrees to 40 degrees.

  The invention according to claim 2 of the present invention is the gas barrier film according to claim 1, wherein the water-soluble polymer is polyvinyl alcohol.

  The invention according to claim 2 of the present invention is the gas barrier film according to claim 1, wherein the water-soluble polymer is polyvinyl alcohol.

  The invention according to claim 3 of the present invention is the gas barrier film according to claim 1 or 2, wherein the inorganic compound is a hydrolyzate of one or more kinds of metal alkoxides. is there.

  According to a fourth aspect of the present invention, in the gas barrier film according to any one of the first to third aspects, the gas barrier coating layer is previously subjected to a surface treatment by plasma treatment. This is a gas barrier film.

  The invention according to claim 5 of the present invention is the gas barrier film according to any one of claims 1 to 4, wherein an inorganic material having a thickness of 5 to 100 nm is provided between the base material and the gas barrier film layer. The gas barrier film is characterized in that an oxide vapor deposition layer is provided.

  The invention according to claim 6 of the present invention is characterized in that a thermoplastic resin is laminated on the gas barrier film layer of the gas barrier film according to any one of claims 1 to 5. It is a laminate.

  According to the gas barrier film of the present invention, there is provided a gas barrier film in which a gas barrier film layer composed of a water-soluble polymer and an inorganic compound is provided on at least one surface of a plastic film substrate, the gas barrier film layer. When the surface of the polymer is measured using X-ray photoelectron spectroscopy (XPS), the functional group ratio D = (C) of the carbon-carbon bond (C—C) and the carbon-hydroxyl bond (C—OH) of the water-soluble polymer. -OH / C-C) is set to 0.35 or more and 0.77 or less, and the contact angle of the gas barrier coating layer surface with water is set to 28 to 40 degrees to control the physical property state of the gas barrier coating layer surface. Has been.

  Therefore, when the thermoplastic resin is melt-extruded and laminated directly to the gas barrier film layer of the gas barrier film, the adhesion between the gas barrier film layer of the gas barrier film and the thermoplastic resin becomes good, and the thermoplastic resin In contrast, a gas barrier film having good adhesion strength can be obtained, and an excellent effect of producing an excellent gas barrier laminate having good adhesion strength between the gas barrier film and the thermoplastic resin can be obtained.

  Moreover, according to the gas barrier film of the present invention, a gas barrier laminate can be produced by extruding and laminating a thermoplastic resin on the surface of the gas barrier film without being restricted by the material of the thermoplastic resin. As described above, since there is no limitation on the thermoplastic resin, a general thermoplastic resin is used for the gas barrier film surface of the present invention, and an anchor coating agent coating using an organic solvent is applied to the gas barrier coating layer. In addition, since processing such as ozone treatment to the extruded and melted thermoplastic resin and its process are not required, it can be applied to various packaging materials.

  Further, according to the gas barrier laminate of the present invention, the gas barrier film of the present invention in which the physical property state of the gas barrier coating layer surface is controlled as described above, and melt extrusion extrusion lamination on the gas barrier coating layer surface of the laminated film. Since the physical property state of the gas barrier coating layer surface in the gas barrier film is controlled as described above, the adhesion between the gas barrier coating layer and the thermoplastic resin is It will be very good.

  Therefore, when the gas barrier laminate of the present invention is used as a packaging container by heat-sealing as a packaging film material for manufacturing a packaging container for hermetically packaging contents such as food, the container is boiled. Even if heat sterilization treatment such as retort or the like is performed, there is an effect that it is possible to provide a gas barrier laminate capable of suppressing a decrease in adhesion strength.

  In addition, since the gas barrier laminate of the present invention is not limited in thermoplastic resin, a general thermoplastic resin can be used. When extrusion lamination is performed, an anchor coating agent is applied to the gas barrier coating layer. Since it is not necessary to apply ozone treatment to the work or thermoplastic resin, it can be applied to various packaging materials.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating an example of the gas barrier film 11 of the present invention. The gas barrier film 11 of the present invention has a structure in which a gas barrier coating layer 3 or an inorganic oxide vapor deposition layer 2 and a gas barrier coating layer 3 are sequentially formed on one surface (front surface or back surface) of a plastic film substrate 1. The surface of the gas barrier coating layer 3 is provided with a surface-treated surface 4 that has been surface-treated as will be described later.

  FIG. 2 is a cross-sectional view illustrating an example of the gas barrier laminate 12 of the present invention. The gas barrier laminate 12 has a surface-treated surface on the surface of the gas barrier coating layer 3 of the gas barrier film 11 in which the inorganic oxide vapor deposition layer 2 and the gas barrier coating layer 3 are sequentially formed on one surface of the plastic film substrate 1. 4 is obtained by laminating and extruding a thermoplastic resin through 4 and laminating the thermoplastic resin layer 5.

  Further, the gas barrier laminate 12 of the present invention may be formed by laminating the thermoplastic resin layer 5 on both surfaces of the plastic film substrate 1, and the inorganic oxide vapor deposition layer 2 and the gas barrier coating layer of the gas barrier film 11. 3 may be formed on the other surface of the plastic film substrate 1 on which the inorganic oxide deposition layer 2 and the gas barrier coating layer 3 are not interposed. The thermoplastic resin layer 5 may be multilayered. When the thermoplastic resin layer 5 is laminated on both sides of the plastic film substrate 1 via the inorganic oxide vapor-deposited layer 2 and the gas barrier coating layer 3, it is necessary on the gas barrier coating layer 3 on one side. The surface treatment layer 4 can be formed according to the above.

  First, the gas barrier film 11 of the present invention will be described in detail. The plastic film substrate 1 (for example, a plastic film) of the gas barrier film 11 may be anything as long as it is generally used as the substrate of this gas barrier film or gas barrier laminate, for example, polyethylene terephthalate (PET). And polyester (saturated polyester) films such as polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polycarbonate films, polyacrylonitrile films, and polyimide films. The film substrate 1 may be either stretched or unstretched, and preferably has mechanical strength and dimensional stability. Of these, polyethylene terephthalate film, polyamide film, and polypropylene film are preferably used.

  The thickness of the substrate 1 is not particularly limited in the present invention, and in consideration of suitability as a packaging material, a film obtained by laminating films having different properties other than a single film can be used. In consideration of workability when the thermoplastic resin layer 5 is formed by extrusion lamination, the thickness of the substrate 1 is preferably in the range of 3 to 200 μm, particularly preferably 6 to 30 μm. .

  An inorganic oxide vapor deposition layer 2 can be formed on the plastic film substrate 1 in order to provide gas barrier properties. The inorganic oxide vapor deposition layer 2 is made of a vapor deposition film of an inorganic oxide such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or a mixture thereof, and has transparency and gas barrier properties such as oxygen and water vapor. Any layer may be used. Considering various heat sterilization resistances, it is more preferable to use aluminum oxide and silicon oxide among these. However, the inorganic oxide vapor deposition layer 2 which is the vapor deposition layer of this invention is not limited to the inorganic oxide mentioned above, If it is a material suitable for the said conditions, it can be used suitably.

  The thickness of the inorganic oxide vapor deposition layer 2 that is the vapor deposition layer varies depending on the type and configuration of the inorganic compound used, but is generally within 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. In addition, when the film thickness exceeds 300 nm, the inorganic oxide vapor deposition layer 2 which is a thin film vapor deposition layer cannot maintain flexibility, and due to external factors such as bending after film formation and tension, There is a problem because the inorganic oxide vapor deposition layer 2 which is a vapor deposition layer may be cracked. More preferably, the thickness of the vapor deposition layer 2 is in the range of 10 to 150 nm.

  There are various methods for forming the inorganic oxide vapor deposition layer 2, which is a vapor deposition film (thin film layer) made of an inorganic oxide, on the plastic film substrate 1, and can be formed by a normal vacuum vapor deposition method. In addition, other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (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 the electron beam heating method should be used in consideration of the wide selection of evaporation materials. Is more preferable. Further, in order to improve the adhesion between the inorganic oxide vapor-deposited layer 2 and the substrate 1 and the denseness of the inorganic oxide vapor-deposited layer 2 which is a vapor-deposited thin film layer, vapor deposition is performed using a plasma assist method or an ion beam assist method. Is also possible. In order to increase the transparency of the deposited film, it is possible to use reactive deposition in which various gases such as oxygen are blown during the deposition.

  In order to reinforce the adhesion between the film substrate 1 and the inorganic oxide deposition layer 2, the surface of the substrate 1 may be subjected to a surface treatment such as plasma treatment or corona treatment. An anchor coat layer may be provided between the layers 2. By providing these layers, the gas barrier film 11 can have heat sterilization resistance such as retort treatment and boil treatment.

  Next, the gas barrier coating layer 3 will be described. The gas barrier coating layer 3 is formed of a water-soluble polymer and an inorganic compound. Examples of the water-soluble polymer include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like. 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.

The inorganic compound forming the gas barrier coating layer 3 is obtained by hydrolyzing one or more metal alkoxides. The metal alkoxide is a compound represented by the general formula, M (OR) _n (M: metal such as Si, Ti, Al, Zr, O: oxygen, alkyl group such as R: CH ₃ , C ₂ H ₅ ). For example, tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxy aluminum [Al (O-iso-C ₃ H ₇ ) ₃ ] are relatively stable in an aqueous solvent after hydrolysis. Preferably used.

  The gas barrier coating layer 3 is prepared by mixing a water-soluble polymer dissolved in water or a water / alcohol mixed solvent with a metal alkoxide that has been subjected to a treatment such as direct or prehydrolysis, and this mixed solution is mixed. After coating on the substrate 1 or the inorganic oxide vapor deposition layer 2, it is formed by heating and drying.

  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.

  When PVA is used as the water-soluble polymer, the proportion of PVA in the mixed solution is desirably 20 wt% (wt%) or more and 50 wt% or less of the total solid content of the mixed solution, and more preferably 25 to 40 wt%. It is in the range. If the PVA is less than 20 wt%, the flexibility of the film is impaired, so that it is difficult to form the gas barrier coating layer 3. Moreover, when more than 50 wt%, since sufficient barrier property cannot be provided to the gas barrier film 11, it is not preferable.

  By adding a silane coupling agent to the mixed solution for forming the gas barrier film layer 3, the water resistance of the gas barrier film layer 3 can be improved. It is possible to better prevent the deterioration of barrier properties under humidity. When an organic functional group of the silane coupling agent is selected from those having a vinyl group, an epoxy group, a methacryloxy group, a ureido group, or an isocyanate group, the water resistance is further improved because the functional group is hydrophobic.

  When converted to a weight ratio after hydrolysis, the silane coupling agent is 12 wt% or less of the total solid content in the mixed solution, and the total of PVA and the silane coupling agent is 20 wt% or more and 50 wt% or less of the total solid content. Need to be. When the amount of the silane coupling agent is large, the ability as the gas barrier coating layer 3 cannot be obtained, which is not preferable.

  Surface treatment by plasma treatment can be performed on the surface after forming the gas barrier coating layer 3 composed of a water-soluble polymer and an inorganic compound. Among plasma treatments, low-temperature plasma treatment performed in vacuum, particularly reactive ion etching (RIE) treatment is effective. By performing this RIE process, a chemical process such as giving a functional group to the surface using the generated radicals or ions, and a physical process such as ion etching of the surface to clean up or smooth out impurities, etc. These two processes can be performed simultaneously. Such treatment not only improves the adhesion with the thermoplastic resin, but also makes it possible to suppress a decrease in adhesion even when a heat sterilization treatment such as a boil treatment or a retort treatment is performed.

  Other surface treatment methods include corona treatment, but corona treatment can add functional groups, but physical effects cannot be obtained, and in such treatment, the initial adhesion strength can be increased. However, strength does not develop after boiling and retorting. The surface treatment method is not particularly limited as long as it is a treatment that results in the following surface state other than the above-described RIE treatment. Further, the processing conditions can be appropriately determined depending on each processing method.

FIG. 3 is a graph showing the binding energy intensity distribution (C1s) with the binding energy (Binding Energy) on the horizontal (x) axis and the energy intensity scaled on the vertical (y) axis, and the gas barrier coating layer 3 It is a waveform of the C1s peak obtained from X-ray photoelectron spectroscopy (XPS) measurement of the surface of the gas barrier coating layer 3 when PVA is used as the water-soluble polymer on the surface. As measurement conditions, MgKα is used as an X-ray source, and the output is 100 W. The C1s waveform obtained from the measurement is separated, and the functional group ratio D (C—O) is determined from the peak intensities of the C—C bonds and C—OH bonds of the water-soluble polymer on the surface of the gas barrier coating layer 3.
H / C-C).

  In FIG. 3, 21 is a bond peak of C—C bond, 22 is a bond peak of C—OH bond, and a bond peak 21 of C—C bond appears near 285.0 eV, and C—OH appears near 286.5 eV. A bond peak 22 of bonds appears.

  In the gas barrier film of the present invention, the functional group ratio D (C—OH / C—C) of the C—C bond and the C—OH bond of the water-soluble polymer on the surface of the gas barrier coating layer 3 is 0.35 or more and 0. .77 or less (0.35 ≦ D ≦ 0.77) is desirable, and the gas barrier coating layer 3 is surface-treated to control the functional group ratio D to such a value. .

  When the functional group ratio D of the water-soluble polymer on the surface of the gas barrier coating layer 3 is smaller than 0.35 (D <0.35), the surface treatment of the gas barrier coating layer 3 proceeds excessively, so Not only the adhesion is lowered, but also the function as the gas barrier coating layer 3 is impaired. On the other hand, when it is larger than 0.77 (D> 0.77), the effect of the surface treatment of the gas barrier coating layer 3 is poor and the functional group is not introduced, so that the gas barrier coating layer 3 has sufficient adhesion strength to the thermoplastic resin. Cannot be obtained.

  When the gas barrier laminate 12 of the present invention is produced by melt extrusion extrusion laminating the thermoplastic resin layer 5 on the surface of the gas barrier film 11 of the gas barrier film 11 of the present invention, In order for the adhesive strength with the plastic resin layer 5 to be strong, the functional group ratio D on the surface of the gas barrier coating layer 3 is in the surface state of the above numerical values, and the gas barrier coating When the contact angle of water on the surface of the layer 3 is measured, the contact angle θ needs to be in the range of 28 degrees to 40 degrees (28 degrees ≦ θ ≦ 40 degrees).

  Even when the functional group ratio D (C—OH / C—C) on the surface of the gas barrier coating layer 3 is in the above range, the contact angle θ after the surface treatment is larger than 40 degrees (θ> 40 degrees). In this case, both chemical and physical effects on adhesion cannot be obtained, and when it is less than 27 degrees (θ <27 degrees), the hydrophilicity is high, so during boil / retort treatment Since water permeates, even if the initial adhesion strength is good, there is a risk of a significant decrease in strength after the heat sterilization treatment.

  In the gas barrier film of the present invention, when the thermoplastic resin layer 5 is laminated on the gas barrier film layer 3 having the surface as described above by melt extrusion lamination, the gas barrier film layer 3 and the thermoplastic resin layer 5 are formed. Adhesion is improved. The thermoplastic resin is not particularly limited as long as it can be laminated by a melt extrusion lamination method. For example, a low density polyethylene resin, a high density polyethylene resin, a medium density polyethylene resin, an ethylene-vinyl acetate copolymer, Ethylene-α-olefin copolymer, ethylene-α, β-unsaturated carboxylic acid copolymer or ester compound or ionic cross-linked product thereof, polypropylene resin, propylene-α-olefin copolymer, acid anhydride-modified polyolefin, epoxy Examples thereof include resins such as modified polyolefins. These may be a single substance or a blend of two or more kinds.

  Further, thermoplasticity in producing the gas barrier laminate 12 of the present invention by laminating the thermoplastic resin layer 5 by melt extrusion lamination of the thermoplastic resin on the surface of the gas barrier film layer 3 of the gas barrier film 11 of the present invention. The melt extrusion temperature at the time of laminating the resin layer 5 is not particularly limited, and can be appropriately determined depending on the resin used.

The thickness of the thermoplastic resin layer 5 of the gas barrier laminate 12 of the present invention is preferably 5 to 200 μm, more preferably 5 to 100 μm. When the thickness is less than 5 μm, it is difficult to extrude uniformly, and the thickness of the layer becomes non-uniform. When the thickness is greater than 200 μm, for example, when the gas barrier laminate of the present invention is used as a film material for manufacturing a gas barrier sealed packaging container and the thermoplastic resin layer 5 is heat sealed, the heat seal strength is weakened. For example, the physical properties of the gas barrier laminate for manufacturing a packaging container may be reduced.

  In addition, the thermoplastic resin used for the thermoplastic resin layer 5 laminated on the gas barrier laminate 12 of the present invention has a slip agent, an antistatic agent, Additives such as antifogging agents, ultraviolet absorbers and antioxidants, and inorganic fillers such as silica and titanium oxide can be added. Further, the thermoplastic resin layer 5 can be extruded together with other thermoplastic resins, that is, multilayer lamination can be performed by a coextrusion method. Further, another plastic film can be laminated on the thermoplastic resin layer 5.

  Examples of the gas barrier film and gas barrier laminate of the present invention will be specifically described below. The present invention is not limited to these examples.

<Example 1>
On one surface of a polyethylene terephthalate (PET) film having a thickness of 12 μm as a plastic film substrate 1, metal aluminum is evaporated by a vacuum vapor deposition apparatus using an electron beam heating method, oxygen gas is introduced therein, and a thickness of 15 nm is introduced. Aluminum oxide (inorganic oxide) was vapor-deposited to form an inorganic oxide vapor-deposited layer 2.

On the inorganic oxide vapor-deposited layer 2 made of aluminum oxide of the base material 1, a solution obtained by mixing the following liquid A, liquid B and liquid C at a mixing ratio (wt%) of 70/25/5 is gravure coated. By applying and drying by the method, a gas barrier film layer 3 having a thickness of 0.3 μm was formed to prepare a gas barrier film.
Liquid A: 72.1 g of hydrochloric acid (0.1N) was added to 17.9 g of tetraethoxysilane (hereinafter referred to as TEOS) and 10 g of methanol, and the mixture was stirred for 30 minutes to hydrolyze to have a solid content of 5 wt. % (SiO ₂ equivalent) hydrolysis solution.
-B liquid: 5 wt. % Water / methanol solution (water / methanol weight ratio = 95/5)
Solution C: Hydrochloric acid (1N) was gradually added to β- (3,4 epoxycyclohexyl) trimethoxysilane and isopropyl alcohol (IPA solution), and the mixture was stirred for 30 minutes for hydrolysis, and then water / IPA = 1/1. Hydrolysis is performed with the solution to obtain a solid content of 5 wt. Hydrolysis solution adjusted to% (R ₂ Si (OH) ₃ conversion).

Further, the surface of the gas barrier coating layer 3 of the above gas barrier film is subjected to a plasma treatment by reactive ion etching (RIE) under the conditions of an applied power of 120 W and a plasma density E = 200 W · sec / m ^2. This was performed to obtain a gas barrier film 11 (I) of the present invention (see FIG. 1). Note that an argon / oxygen mixed gas was used as the surface treatment gas, the treatment unit pressure was 2.0 Pa, and the self-bias was 400V.

<Example 2>
After applying and forming the gas barrier coating layer 3 in Example 1, plasma treatment by reactive ion etching (RIE) was performed as surface treatment under the conditions of applied power 60 W and plasma density E = 100 W · sec / m ^2. A gas barrier film was prepared in the same manner as in Example 1 except that the surface treatment was performed, and this was used as the gas barrier film 11 (II) of the present invention. Note that an argon / oxygen mixed gas was used as the surface treatment gas, the treatment unit pressure was 2.0 Pa, and the self-bias was 300V.

<Example 3>
After applying and forming the gas barrier coating layer 3 in Example 1, plasma treatment by reactive ion etching (RIE) was performed as surface treatment under the conditions of applied power of 500 W and plasma density E = 900 W · sec / m ^2. A gas barrier film was prepared in the same manner as in Example 1 except that the surface treatment was performed, and this was used as the gas barrier film 11 (III) of the present invention. Note that an argon / oxygen mixed gas was used as the surface treatment gas, the treatment unit pressure was 2.0 Pa, and the self-bias was 750V.

<Example 4>
After applying and forming the gas barrier coating layer 3 with the compounding ratio of the solution A, the solution B and the solution C forming the gas barrier coating layer 3 in Example 1 being 62/28/10, the applied power is 250 W as the surface treatment. A gas barrier film was prepared in the same manner as in Example 1 except that surface treatment was performed by performing plasma treatment by reactive ion etching (RIE) under the condition of plasma density E = 450 W · sec / m ² . This was designated as gas barrier film 11 (IV) of the present invention. Note that an argon / oxygen mixed gas was used as the processing gas, the processing unit pressure was 2.0 Pa, and the self-bias was 600V.

<Example 5>
A gas barrier film was prepared in the same manner as in Example 1 except that the surface treatment was not performed on the gas barrier film layer 3 of the gas barrier film in Example 1, and this was designated as gas barrier film 11 (V).

<Example 6>
In Example 1 described above, as a surface treatment for the gas barrier coating layer 3 of the gas barrier film, an applied power of 500 W and a discharge amount of 10 W · min. A gas barrier film was prepared in the same manner as in Example 1 except that the surface treatment was performed by performing a corona treatment under the condition of / m ^2, and this was designated as a gas barrier film 11 (VI).

<Example 7>
In Example 1, the gas barrier coating layer 3 of the gas barrier film was subjected to plasma treatment by reactive ion etching (RIE) under the conditions of an applied power of 250 W and a plasma density E = 1500 W · sec / m ² as a surface treatment. A gas barrier film was prepared in the same manner as in Example 1 except that the treatment was performed, and this was designated as gas barrier film 11 (VII). Note that an argon / oxygen mixed gas was used as the processing gas, the processing unit pressure was 2.0 Pa, and the self-bias was 650V.

<Example 8>
In Example 1, the gas barrier coating layer 3 of the gas barrier film was subjected to plasma treatment by reactive ion etching (RIE) under the conditions of applied power of 30 W and plasma density E = 50 W · sec / m ² as surface treatment. A gas barrier film was prepared in the same manner as in Example 1 except that the treatment was performed, and this was designated as gas barrier film 11 (VIII). Note that an argon / oxygen mixed gas was used as the processing gas, the processing unit pressure was 2.0 Pa, and the self-bias was 180V.

<Surface condition analysis method by X-ray photoelectron spectroscopy>
Surface analysis was performed by X-ray photoelectron spectroscopy for the gas barrier coating layers 5 of the gas barrier films 11 (I) to 11 (VIII) prepared in Examples 1 to 8 above. As the X-ray source of the X-ray photoelectron spectrometer (JPS-90MXV manufactured by JEOL Ltd.) used for the measurement, non-monochromated MgKα (1253.6 eV) was used, and the output was measured at 100 W (10 kV-10 mA). . A mixed function of a Gaussian function and a Lorentz function was used for the waveform separation analysis of the C1s waveform, and the charge correction was performed by correcting the bond peak intensity 21 of the C—C bond (see FIG. 3) as 285.0 eV. The bond peak intensity of the C—C bond and the C—OH bond was determined from waveform separation analysis, and the functional group ratio D (C—OH / C—C) was determined from these values.

<Contact angle measurement>
The contact angle θ of each gas barrier film 11 (I) to 11 (VIII) prepared in Examples 1 to 8 with respect to water is determined by the Japanese Industrial Standard JIS-R3257 “Wetability Test of Substrate Glass Surface”. According to the test method defined by the sessile drop method in “Method”, measurement was performed using a test measuring instrument (“CA-V type” manufactured by Kyowa Interface Science Co., Ltd.).

<Creation of gas barrier laminate>
On each gas barrier film layer 5 of each of the gas barrier films 11 (I) to 11 (VIII) prepared in Examples 1 to 8, low density polyethylene (LDPE) as a thermoplastic resin is melt-extruded temperature of the resin. Extrusion lamination was performed with an extrusion lamination machine at 320 ° C. and a thickness of 15 μm to laminate the thermoplastic resin layer 5 to obtain a gas barrier laminate 12. (See Figure 2)
Further, if necessary, as the thermoplastic resin layer 5 of the gas barrier laminate 12, a sand base material (thermoplastic resin layer, pouch, etc., sealed packaging container on the thermoplastic resin layer 5 of low density polyethylene (LDPE). A 60 μm-thick low-density polyethylene (LDPE) film or linear low-density polyethylene (LLDPE) film was laminated and laminated as a heat sealant layer for production).

<Making pouch containers>
The gas barrier laminate 12 (gas barrier laminate film) having a substantially rectangular shape is used as a heat seal layer by stacking two sheets of the thermoplastic resin layer 5 with the inner surface of the container being used, and 3 of them are used as seal portions. Heat-seal the sides, create pouches with one side as the opening, fill each tap water as contents from each pouch opening, heat-seal the opening and seal-wrap and seal on the four sides A sealed packaging pouch with tap water was prepared.

<Boil processing>
Each of the prepared sealed packaging pouches was boiled at 95 ° C. for 60 minutes.

<Lamination strength measurement method>
The laminate strength between the gas barrier film 11 and the thermoplastic resin layer 5 of the gas barrier laminate 12 of each pouch before and after the above boil treatment was determined according to Japanese Industrial Standard JIS-K6854-3: 1999 “Adhesive—Peeling Adhesive Strength. According to the test method prescribed | regulated in "Sam test method-Part 3: T-type peeling", it measured using the test measuring machine (Orientec company make, Tensilon universal testing machine RTC-1250).

  Below, the functional group ratio D (C—OH / C—C) in the surface treatment surface 4 of the gas barrier coating layer 3 of each of the gas barrier films 11 (I) to 11 (VIII) prepared in Examples 1 to 8 above. And the contact angle θ of water and the sealing of each pouch made by the gas barrier laminate 12 in which the thermoplastic resin layer 5 is laminated on the surface of the gas barrier coating layer 3 of each of the gas barrier films 11 (I) to 11 (VIII). The measurement results of the laminate strength (N / 15 mm) in the packaging seal part are shown in Table 1 below.

上記実施例１〜４により作成したガスバリア性フィルム１１（Ｉ）〜１１（ＩＶ）により作成したガスバリア積層体１２では、ガスバリア性被膜層３／熱可塑性樹脂層５の間の密着強度に優れており、プラスチックフィルム基材１へのアンカーコート剤や押し出し時
の溶融熱可塑性樹脂へのオゾン処理等を行わなくても、プラスチックフィルム基材１（及び無機酸化物蒸着層２、ガスバリア性被膜層３）と熱可塑性樹脂層５との密着性が良好であり、さらにボイル処理を行っても、プラスチックフィルム基材１と熱可塑性樹脂５との密着低下が少なく、ボイル後、１日以上置けば、ボイル前の密着強度の５〜７割程度まで回復するようなガスバリア性積層体１２を提供することが可能であった。

In the gas barrier laminate 12 produced by the gas barrier films 11 (I) to 11 (IV) produced in Examples 1 to 4, the adhesion strength between the gas barrier coating layer 3 and the thermoplastic resin layer 5 is excellent. The plastic film substrate 1 (and the inorganic oxide vapor deposition layer 2 and the gas barrier coating layer 3) can be used without the need for an anchor coating agent on the plastic film substrate 1 or ozone treatment of the molten thermoplastic resin during extrusion. And the thermoplastic resin layer 5 have good adhesion, and even when the boil treatment is performed, there is little decrease in the adhesion between the plastic film substrate 1 and the thermoplastic resin 5, and if it is left for one day or more after boiling, It was possible to provide the gas barrier laminate 12 that recovered to about 50 to 70% of the previous adhesion strength.

  However, in the gas barrier laminate 12 prepared from the gas barrier films (V) to (VIII) prepared in Examples 5 to 8, adhesion between the gas barrier coating layer 3 / thermoplastic resin layer 5 is obtained when boiling is performed. The strength disappeared and it did not recover even after being left for one day.

It is sectional drawing which shows an example of the gas barrier film of this invention. It is sectional drawing which shows an example of the gas barrier laminated body laminated | stacked and formed using the gas barrier film of this invention. It is a measurement graph of the separation analysis spectrum which shows the coupling | bonding intensity | strength of CC bond and C-OH bond obtained by the X-ray photoelectron spectroscopy measurement which shows the surface treatment state in the surface treatment surface of the gas barrier film layer of a gas barrier film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic film base material 2 ... Inorganic oxide vapor deposition layer 3 ... Gas barrier property coating layer 4 ... Surface treatment surface 5 ... Thermoplastic resin layer 11 ... Gas barrier property film 12 ... Gas barrier property laminated body 21 ... CC bond peak 22 ... C-OH bond peak

Claims (6)

In a laminated film in which a gas barrier coating layer comprising a water-soluble polymer and an inorganic compound is provided on at least one surface of a plastic film substrate, at least the surface of the gas barrier coating layer has the following surface state (1), A gas barrier film, which is a surface-treated surface 4 satisfying both of (2).
(1) When the surface-treated surface 4 on the surface of the gas barrier coating layer is measured using X-ray photoelectron spectroscopy (XPS), the carbon-carbon bond (CC) and the carbon-hydroxyl bond (C -OH) has a functional group ratio D = (C-OH / C-C) of 0.35 or more and 0.77 or less.
(2) The contact angle with respect to water of the surface treatment surface 4 of the gas barrier coating layer surface is 28 degrees to 40 degrees.   The gas-barrier film according to claim 1, wherein the water-soluble polymer is polyvinyl alcohol.   The gas barrier film according to claim 1 or 2, wherein the inorganic compound is a hydrolyzate of one or more metal alkoxides.   The gas barrier film according to any one of claims 1 to 3, wherein the gas barrier coating layer has been subjected to surface treatment by plasma treatment in advance.   The gas barrier film according to any one of claims 1 to 4, wherein an inorganic oxide vapor deposition layer having a thickness of 5 to 100 nm is provided between the base material and the gas barrier film layer.   A gas barrier laminate, wherein a thermoplastic resin is laminated on the gas barrier coating layer of the gas barrier film according to any one of claims 1 to 5.

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