JP2020124857A - Laminate film and production method for the same, and packaging container and production method for the same - Google Patents

Abstract

To provide a laminate film produced by stacking a gas barrier film layer and a thermoplastic resin layer with a fused adhesive resin therebetween and pressing the layers with a heating roller, in which a high temperature of the heating roller is unnecessary and the layers can be heat-sealed to achieve high adhesion strength.SOLUTION: A laminate film is produced by stacking a gas barrier film layer 10A, an adhesive resin layer 20 and a thermoplastic resin layer 30, in this order. A maleic acid-grafted modified polypropylene is used for an adhesive resin that constitutes the adhesive resin layer 20.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a laminated film and a manufacturing method thereof, and a packaging container and a manufacturing method thereof.

As a packaging material used for packaging foods, pharmaceuticals, etc., in general, gas that modifies the contents, such as water vapor, oxygen, and the like, in order to suppress the alteration and decay of the contents and to retain their functions and properties. A laminated film having a gas barrier property of blocking the entry of the gas is used. As the laminated film having a gas barrier property, for example, on the outer surface of a substrate film such as a polyester tel film, a barrier layer formed of a vapor deposition layer of a metal or a metal oxide is formed, and an adhesive layer is provided on the inner surface of the barrier layer. A laminated film in which a sealant layer is laminated is known (Patent Document 1).

By the way, the laminated film is required to have a high temperature resistance (retort resistance) that does not cause delamination (peeling) even when subjected to a high temperature sterilization treatment. In addition, even if the content contains liquid seasonings such as vinegar, oil, bath agents (containing alcohol), poultices, and other volatile substances with strong penetrating power, the content resistance does not cause delamination. It is also required to have

In the laminated film, a urethane two-component curing type dry laminating adhesive is generally used as an adhesive for forming an adhesive layer even in the use of a resistant packaging material such as a retort heat sterilization packaging material. However, when an adhesive for dry lamination is used, it takes a long time to cure the adhesive in order to obtain sufficient retort resistance and content resistance. Therefore, it is difficult to manufacture the adhesive in a short time. Further, when the laminated film is wound around the winding core at the time of manufacturing, the film near the winding core may be wound up due to heat and a load may be applied during curing, so that the film may be damaged.

On the other hand, there is also known a method of laminating a gas barrier film layer and a thermoplastic resin layer with a molten adhesive resin interposed therebetween, and then laminating by pressing with a heating roll. As this adhesive resin, maleic acid graft modification is carried out. It has also been proposed to use polypropylene resin (for example, Patent Document 2). However, in this method, sufficient adhesive force could not be obtained unless the temperature of the heating roll was set to a high temperature of 140° C. or higher. When heated with such a high temperature roll, the film may be subjected to a heat load as in the case of using the adhesive for dry lamination, and the film may be damaged.

JP, 2011-46006, A Japanese Patent Publication No. 5-21955

The present invention has been made according to the technical circumstances as described above, the gas barrier film layer and the thermoplastic resin layer are laminated via a molten adhesive resin, in a laminated film laminated by pressing with a heating roll, It is an object of the present invention to provide a laminated film which does not require the temperature of the heating roll to be high and can be laminated with high adhesive strength.

That is, the invention according to claim 1 is a laminated film in which a gas barrier film layer and a thermoplastic resin layer are laminated via a melted adhesive resin,
The adhesive resin contains a maleic acid graft modified polypropylene mixed with boron nitride, which is a laminated film.

Next, the invention described in claim 2 is the laminated film according to claim 1,
The laminated film is characterized in that the compounding amount of boron nitride in the adhesive resin is 3 to 5% by mass.

Next, the invention described in claim 3 is the laminated film according to claim 1 or 2,
In the laminated film, the gas barrier film layer is formed by laminating a metal oxide vapor-deposition layer on the adhesive resin layer side of a base film.

Next, the invention described in claim 4 is the laminated film according to claim 3,
A gas barrier coating layer is laminated on the vapor deposition layer,
The gas barrier coating layer is composed of a silicon-based gas barrier composite structure, which is a laminated film.

Next, the invention described in claim 5 is the laminated film according to claim 4,
A laminated film characterized in that the silicon-based gas barrier composite structure is a silicon-based gas barrier composite structure formed by reaction of the following compounds 1 to 3.
Compound 1: A silicon compound represented by the general formula Si(OR ¹ ) ₄ (R ¹ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ) or a hydrolyzate thereof.
Compound 2: Silicon represented by the general formula (R ² Si(OR ³ ) ₃ ) _n (R ² represents an organic functional group, R ³ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ). A compound or a hydrolyzate thereof.
Compound 3: Water-soluble polymer.

Next, the invention according to claim 6 is the laminated film according to any one of claims 3 to 5,
A primer layer is disposed between the base film and the vapor deposition layer,
This primer layer is a laminated film characterized by being a silicon-based composite structure formed by the reaction of the following compounds 4 to 6.
Compound 4: General formula R ⁴ Si(OR ⁵ ) ₃ (R ⁴ : an alkyl group, a vinyl group, an alkyl group having an isocyanate group, an alkyl group having a glycidoxy group or an alkyl group having an epoxy group, R ⁵ : an alkyl group A trifunctional organosilane represented by the formula) or a hydrolyzate thereof.
Compound 5: Acrylic polyol.
Compound 6: Isocyanate compound.

Next, the invention according to claim 7 is the laminated film according to any one of claims 3 to 6, wherein
The laminated film is characterized in that the surface of the substrate film on which the vapor deposition layer is formed is plasma-treated.

Next, the invention described in claim 8 is the laminated film according to claim 1 or 2,
In the laminated film, the gas barrier film layer is formed by laminating a gas barrier film layer containing a polycarboxylic acid polymer on the side of the adhesive resin layer of a base film.

Next, the invention described in claim 9 is the laminated film according to claim 1 or 2,
The gas barrier film layer, a gas barrier coating layer containing a phosphorus-based gas barrier composite structure formed by the reaction of a compound of a polyvalent metal and a phosphorus compound, is laminated on the adhesive resin layer side of the substrate film. It is a laminated film characterized by being configured.

Next, the invention according to claim 10 is the method for producing a laminated film according to any one of claims 1 to 9.

Next, the invention described in claim 11 is a packaging container obtained by bag-making the laminated film according to any one of claims 1 to 9.

Next, the invention according to claim 12 is the method for manufacturing the packaging container according to claim 11.

According to the present invention, it is not necessary to raise the temperature of the heating roll, and it is possible to manufacture a laminated film bonded with high bonding strength.

FIG. 1 is a sectional view showing a first specific example of the laminated film of the present invention. FIG. 2 is a sectional view showing a second specific example of the laminated film of the present invention. FIG. 3 is a sectional view showing a third specific example of the laminated film of the present invention. FIG. 4 is a sectional view showing a fourth specific example of the laminated film of the present invention. FIG. 5 is a sectional view showing a fifth specific example of the laminated film of the present invention. FIG. 6 is a schematic configuration diagram showing an example of a hollow anode plasma processing apparatus.

The laminated film of the present invention comprises a gas barrier film layer, an adhesive resin layer and a thermoplastic resin layer laminated in this order. The gas barrier film layer may be any film as long as it has a gas barrier property, but it will be described below with five types of examples. 1 to 5 are cross-sectional views showing examples of laminated films A to E using these five types of gas barrier film layers 10A to 10E.

[Laminated film A]
The laminated film A is an example in which the gas barrier film layer 10A is used, and the gas barrier film layer 10A is formed by laminating a metal oxide vapor deposition layer 12 on a base film 11. Then, the adhesive resin layer 20 and the thermoplastic resin layer 30 are laminated in this order on the vapor deposition layer 11 side to form a laminated film A.

(Base film 11)
Examples of the base film 11 include a resin film.

The resin forming the resin film is not particularly limited, and examples thereof include polyester-based resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene-2,6-naphthalate, polybutylene terephthalate and copolymers thereof. Resins: polyolefin resins such as polyethylene and polypropylene; polyamide resins such as nylon-6, nylon-66 and nylon-12; hydroxyl group-containing polymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers. Among them, polyethylene terephthalate and polyamide resins are preferably used. These resins may be used alone or in combination of two or more.

The base film 11 may be a stretched film or an unstretched film. Among them, a uniaxially stretched film and a biaxially stretched film are preferable, and a biaxially stretched film is more preferable, because they are excellent in mechanical strength and dimensional stability.

The base film 11 may be a single layer made of one resin film, or may be a multi-layer in which two or more resin films are laminated.

The thickness of the base film 11 is not particularly limited and may be, for example, 3 to 200 μm, preferably 6 to 30 μm.

In addition, prior to the formation of the metal oxide vapor deposition layer 12, by performing a plasma treatment on the vapor deposition layer forming surface of the base film 11, the adhesion between the base film 11 and the metal oxide vapor deposition layer 12 can be improved.

The plasma treatment is preferably reactive ion etching (reactive ion etching, RIE) mode plasma treatment. Specifically, for example, RIE processing using the horo-anode/plasma processing apparatus 100 illustrated in FIG. 6 can be mentioned.

The hollow anode plasma processing apparatus 100 includes a processing roll 101 as an anode. The cathode 102 and the shielding plates 103 arranged at both ends of the cathode 102 are arranged outside the processing roll 101 so as to face the processing roll 101. The cathode 102 has a box shape with an opening on the processing roll 101 side. The shield plate 103 is formed in a curved surface shape along the processing roll 101.

The gas introduction nozzle 104 is arranged above the cathode 102. The gas introduction nozzle 104 introduces gas into the gap 105 between the cathode 102 and the shielding plate 103 and the processing roll 101. The matching box 106 is arranged on the back surface of the cathode 102.

The RIE processing of the base film by the horo-anodic plasma processing apparatus 100 is performed as follows.

A voltage is applied from the matching box 106 to the cathode 102 while the base film 107 is being conveyed along the processing roll 101. Plasma is generated in the gap 105 into which the gas is introduced, and the radicals in the plasma are attracted to the side of the processing roll 101, which is the anode, so that the radicals act on the surface of the base film 107.

Further, by making the area of the processing roll 101 as the anode larger than the area of the base film 107 serving as the counter electrode, a large amount of self-bias can be generated on the base film 107. Due to this large self-bias, a sputtering action (physical action) that attracts the ions 108 in the plasma to the base film 107 works. Thereby, when the metal oxide vapor deposition layer 12 is formed on the surface of the base film 11 after the RIE treatment, the adhesion between the base film 11 and the metal oxide vapor deposition layer 12 is improved.

(Metal oxide vapor deposition layer 12)
The metal oxide vapor deposition layer 12 is a layer formed by vapor deposition of a metal oxide. Examples of the metal oxide include silicon oxide and aluminum oxide, and aluminum oxide is preferable.

The method for forming the metal oxide vapor deposition layer 12 is not particularly limited, and examples thereof include a vacuum vapor deposition method and a sputtering method.

The thickness of the metal oxide vapor deposition layer 12 is preferably 100 to 500Å, more preferably 150 to 300Å. If the thickness of the metal oxide vapor deposition layer 12 is not less than the lower limit value, the barrier property is secured. When the thickness of the metal oxide vapor deposition layer 12 is not more than the upper limit value, transparency is secured.

(Adhesive resin layer 20)
The adhesive resin layer 20 is composed of an adhesive resin containing maleic acid graft modified polypropylene (hereinafter referred to as modified PP) as a main component and boron nitride mixed therein. The modified PP is polypropylene obtained by graft-modifying polypropylene with maleic anhydride. Examples of polypropylene include homopolypropylene, block polypropylene, random polypropylene, and propylene-α-olefin copolymer. Examples of the α-olefin include ethylene and 1-butene.

Then, using the modified PP containing such boron nitride as an adhesive resin, the adhesive resin is heated and melted and extruded, and while the adhesive resin has an adhesive force, the gas barrier film layer 10 is formed on both surfaces thereof. By stacking and the thermoplastic resin layer 30 and pressing with a heating roll, these can be integrally bonded and laminated. At this time, the higher the temperature of the heating roll, the stronger the adhesion, but when the temperature is high, the gas barrier film layer 10 may be subjected to a heat load, and the gas barrier film layer 10 may be damaged. It suffices that the temperature of the heating roll is 130° C. or higher. For example, even if the blending amount of boron nitride in the adhesive resin layer 20 is 2% by mass, the adhesive strength when pressed by the heating roll at 130° C. improves. Desirably, the compounding quantity of boron nitride is 3 to 5 mass %.

In addition, when laminating a sealant film on the thermoplastic resin layer 30 as described later, instead of stacking the gas barrier film layer 10 and the thermoplastic resin layer 30 with an adhesive resin therebetween, and then hot-pressing them. It is also possible to integrally laminate the gas barrier film layer 10, the adhesive resin layer 20, the thermoplastic resin layer 30 and the sealant film by laminating a sealant film on the thermoplastic resin layer 30 and then hot-pressing them. It is possible.

As such a laminating method, for example, the adhesive resin is melt-extruded and coated on the gas barrier film layer 10, and then the thermoplastic resin layer 30 is overlapped while the adhesive resin has an adhesive force, and then the heating roll is used. An example is a method in which the gas barrier film layer 10 and the thermoplastic resin layer 30 are adhesively laminated via the adhesive resin layer 20 made of this resin by pressing. When laminating a sealant film on the thermoplastic resin layer 30, the adhesive resin is melt-extrusion coated on the gas barrier film layer 10, the thermoplastic resin layer 30 and the sealant film are overlaid, and the heating roll is heated. By pressing with, the gas barrier film layer 10, the adhesive resin layer 20, the thermoplastic resin layer 30, and the sealant film can be integrally bonded and laminated.

Further, the adhesive resin and the thermoplastic resin are melt-extruded together, coated on the gas barrier film layer 10, and then pressed by a heating roll, so that the gas barrier film layer is passed through the adhesive resin layer 20. It is also possible to adhesively laminate 10 and the thermoplastic resin layer 30. When laminating a sealant film on the thermoplastic resin layer 30, the adhesive resin and the thermoplastic resin are melt-extruded together on the gas barrier film layer 10, and after further stacking the sealant film, a heating roll is used. By pressing, the gas barrier film layer 10, the adhesive resin layer 20, the thermoplastic resin layer 30, and the sealant film can be integrally bonded and laminated.

Further, between the gas barrier film layer 10 and the sealant film, the adhesive resin and the thermoplastic resin are melt-coextruded and pressed by a heating roll to press the gas barrier film layer 10, the adhesive resin layer 20, It is also possible to integrally bond and laminate the thermoplastic resin layer 30 and the sealant film.

The thickness of the adhesive resin layer 20 is preferably 1 to 20 μm, more preferably 7 to 12 μm. When the thickness of the adhesive resin layer 20 is at least the lower limit value, it is easy to prevent delamination from occurring between the gas barrier film layer 10 and the thermoplastic resin layer 30. If the thickness of the adhesive resin layer 20 is not more than the upper limit value, a uniform laminated state can be obtained.

(Thermoplastic resin layer 30)
As the thermoplastic resin forming the thermoplastic resin layer 30, any resin having a heat fusion property can be used. Examples of the thermoplastic resin include linear low density polyethylene (LLDPE), polyethylene, polypropylene, epoxy resin (EP), ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer. Examples thereof include a polymer, an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester copolymer, and a metal cross-linked product thereof. Of these, polypropylene and heat-resistant LLDPE are preferable in consideration of suitability for retort sterilization in food packaging. As these thermoplastic resins, one kind may be used alone, or two or more kinds may be used in combination.

The thickness of the thermoplastic resin layer 30 can be appropriately set according to the purpose and is generally in the range of 15 to 200 μm.

When the packaging container is made into a bag, the thermoplastic resin layer 30 can be used as a sealant layer, but as described above, the thermoplastic resin layer 30 is used by laminating a sealant film. Is also possible.

(Method for producing laminated film A)
As described above, the laminated film A can be manufactured by the following method. That is, first, the vapor deposition layer 12 is formed on the base film 11 to manufacture the gas barrier film layer 10A.

Next, the adhesive resin is melt-extruded and coated on the vapor deposition layer 12 to form the adhesive resin layer 20, and then the thermoplastic resin layer 30 is superposed while the adhesive resin layer 20 has an adhesive force. It may be pressed with a heating roll. In addition, after the adhesive resin layer 20 and the thermoplastic resin layer 30 are melt-coextruded and coated on the vapor deposition layer 12 of the gas barrier film layer 10A, the gas barrier film layer 10A and the thermoplastic resin layer 30 are pressed by a heating roll. It is also possible to adhesively laminate and. When laminating a sealant film on the thermoplastic resin layer 30, the resin mainly containing the modified PP and the thermoplastic resin are melt-extruded between the gas barrier film layer 10A and the sealant film. It is also possible to bond and laminate these by pressing with a heating roll. In any case, it is desirable that the temperature of the heating roll is 130° C. or higher. In order to increase the adhesive strength, it is preferable to set the temperature of the heating roll to 140 to 170°C.

[Laminated film B]
The laminated film B is an example in which the gas barrier film layer 10B is used as the gas barrier film layer, and is the same as the laminated film A except for this point. In the gas barrier film layer 10B, the gas barrier coating layer 13 is laminated on the metal oxide vapor deposition layer 12. That is, the gas barrier film layer 10B has a layer structure in which the metal oxide vapor deposition layer 12 and the gas barrier coating layer 13 are laminated in this order on the base film 11, and the adhesive resin layer 20 is provided on the gas barrier coating layer 13. (See FIG. 2).

In this laminated film B, the base film 11, the metal oxide vapor deposition layer 12, the adhesive resin layer 20, and the thermoplastic resin layer 30 are respectively the base film 11, the metal oxide vapor deposition layer 12, and the adhesiveness in the laminated film A. Since it is similar to the resin layer 20 and the thermoplastic resin layer 30, the description thereof will be omitted and the gas barrier coating layer 13 will be described.

(Gas barrier film layer 13)
As the gas barrier coating layer 13, a silicon-based gas barrier composite structure formed by reacting the following compounds 1 to 3 can be used. In addition to this, an isocyanate component can be blended.
Compound 1: A silicon compound represented by the general formula Si(OR ¹ ) ₄ (R ¹ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ) or a hydrolyzate thereof.
Compound 2: Silicon represented by the general formula (R ² Si(OR ³ ) ₃ ) _n (R ² represents an organic functional group, R ³ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ). A compound or a hydrolyzate thereof.
Compound 3: Water-soluble polymer.

The silicon compound represented by the general formula Si(OR ¹ ) ₄ is tetraalkoxysilane. For example, tetramethoxysilane and tetraethoxysilane. The silicon compound represented by the general formula (R ² Si(OR ³ ) ₃ ) _n is a silane coupling agent. For example, an epoxy silane coupling agent, an amine silane coupling agent, a vinyl silane coupling agent, an acrylic silane coupling agent, etc. can be used. Further, it may be a silane coupling agent having an isocyanate group or an epoxy group. Examples of the water-soluble polymer include organic polymers having a vinyl alcohol moiety such as polyvinyl alcohol, polyvinyl acetate and ethylene-vinyl acetate copolymer. Examples of the isocyanate component include tolylene diisocyanate and xylylene diisocyanate.

In addition, you may use the silane coupling agent which has an isocyanate group as a compound which serves as both an isocyanate compound and a silane coupling agent. For example, 1,3,5-tris (3-trialkoxysilylalkyl) isocyanurate ^{(formula: NCO-R 2 Si (OR} 3) 3) n) or a hydrolyzate thereof.

When the gas barrier coating layer 13 is measured by a time-of-flight secondary ion mass spectrometer (TOF-SIMS), a silicon oxide component, a vinyl alcohol component, an isocyanate component and a silane coupling agent component are detected. Note that TOF-SIMS is a surface analysis method that can measure the mass spectrum of secondary ions generated when the surface is irradiated with ions and obtain information about the constituent elements and the chemical structure of the surface.

The gas barrier coating layer 13 is a clay mineral such as colloidal silica or smectite in consideration of adhesion with adjacent layers, wettability, and suppression of crack generation due to shrinkage, as long as the effect of the present invention is not impaired. Known additives such as stabilizers, colorants, and viscosity modifiers may be added.

The thickness of the gas barrier coating layer 13 is preferably 0.01 to 50 μm. When the thickness of the gas barrier coating layer 13 is at least the lower limit value, excellent gas barrier properties are likely to be obtained. When the thickness of the gas barrier coating layer 13 is equal to or less than the upper limit value, it is easy to prevent cracks from occurring.

The method for forming the gas barrier coating layer 13 is not particularly limited, and examples thereof include a method in which a silicon oxide component or the like is mixed in a solvent, coated on the metal oxide vapor deposition layer 13, and dried. Since the metal alkoxide is difficult to uniformly disperse in an aqueous solvent, it may be hydrolyzed before use.

The coating method is not particularly limited, and examples thereof include a dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, and gravure offset method.

The drying method may be hot air drying, hot roll drying, high frequency irradiation, infrared irradiation, UV irradiation or the like as long as heat is applied to remove the solvent molecules, and two or more of these may be combined.

[Laminated film C]
The laminated film C is an example in which the gas barrier film layer 10C is used as the gas barrier film layer, and is the same as the laminated film A except for this point. In this gas barrier film layer 10B, a primer layer 12c is arranged between the base film 11 and the metal oxide vapor deposition layer 12. That is, the gas barrier film layer 10C has a layer structure in which the primer layer 12c, the metal oxide vapor deposition layer 12, and the gas barrier coating layer 13 are laminated in this order on the base film 11, and the adhesive resin layer 20 is the gas barrier coating. It is laminated on the layer 13 (see FIG. 3).

In this laminated film C, the base film 11, the metal oxide vapor deposition layer 12, the gas barrier film layer 13, the adhesive resin layer 20, and the thermoplastic resin layer 30 are respectively the base film 11 in the laminated film A or the laminated film B. Since it is similar to the metal oxide vapor deposition layer 12, the gas barrier coating layer 13, the adhesive resin layer 20, and the thermoplastic resin layer 30, the description thereof will be omitted and the primer layer 12c will be described.

(Primer layer 12c)
The primer layer 12c enhances the adhesion between the substrate film 11 and the metal oxide vapor deposition layer 12, and can be composed of a silicon-based composite structure formed by reacting the following compounds 4 to 6.
Compound 4: General formula R ⁴ Si(OR ⁵ ) ₃ (R ⁴ : an alkyl group, a vinyl group, an alkyl group having an isocyanate group, an alkyl group having a glycidoxy group or an alkyl group having an epoxy group, R ⁵ : an alkyl group A trifunctional organosilane represented by the formula) or a hydrolyzate thereof.
Compound 5: Acrylic polyol.
Compound 6: Isocyanate compound.

Examples of the trifunctional organosilane include ethyltrimethoxysilane, vinyltrimethoxysilane, isocyanatepropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, and epoxycyclohexylethyltrimethoxysilane. To be Among them, isocyanatopropyltriethoxysilane having an isocyanate group in R ⁴ , γ-isocyanatopropyltrimethoxysilane, glycidoxytrimethoxysilane having a glycidoxy group, and epoxycyclohexylethyltrimethoxysilane having an epoxy group are particularly preferable.

The hydrolyzate of trifunctional organosilane can be obtained by a known method such as a method in which an acid, an alkali or the like is directly added to trifunctional organosilane to perform hydrolysis.

Acrylic polyol is a polymer compound obtained by homopolymerization or copolymerization of an acrylic acid derivative monomer, or among polymer compounds obtained by copolymerizing an acrylic acid derivative monomer and other monomers, It has a hydroxyl group and reacts with the isocyanate group of the isocyanate compound.

Examples of the acrylic acid derivative monomer include ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate and the like.

Examples of the other monomer include styrene.

The acrylic polyol is preferably a homopolymer of one type of acrylic acid derivative monomer selected from ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate; and a copolymer of the acrylic acid derivative and styrene.

The hydroxyl value of the acrylic polyol is preferably 5 to 200 KOHmg/g from the viewpoint of excellent reactivity with the isocyanate compound.

The mass ratio of the acrylic polyol and the trifunctional organosilane is preferably 1/1 to 100/1, more preferably 2/1 to 50/1.

The isocyanate compound is a compound that has two or more isocyanate groups and reacts with an acrylic polyol to form a urethane bond, and serves as a crosslinking agent or a curing agent that enhances the adhesion between the base film 11 and the metal oxide vapor deposition layer 13. To work.

Examples of the isocyanate compound include aromatic isocyanate compounds such as tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), aliphatic isocyanate compounds such as xylene diisocyanate (XDI) and hexalene diisocyanate (HMDI), and aromatic compounds thereof. Examples thereof include polymers having an isocyanate group, obtained by polymerizing a system- or aliphatic-type isocyanate compound and a polyol, and derivatives thereof. As the isocyanate compound, one type may be used alone, or two or more types may be used in combination.

As the compounding ratio of the acrylic polyol and the isocyanate compound, the ratio of the number of isocyanate groups derived from the isocyanate compound to the number of hydroxyl groups derived from the acrylic polyol is preferably 50 times or less, and the isocyanate groups and the hydroxyl groups are equivalent. Particularly preferred. As a result, it is easy to prevent that the amount of the isocyanate compound is too small to cause curing failure, and that the amount of the isocyanate compound is too large to cause blocking and make it difficult to process.

The silicon-based composite structure can be obtained by reacting at least one selected from the group consisting of trifunctional organosilane and its hydrolyzate, an acrylic polyol, and an isocyanate compound in a solvent.

The solvent is not particularly limited as long as it can dissolve and dilute each component, and examples thereof include esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol and isopropyl alcohol; ketones such as methyl ethyl ketone. Kinds; aromatic hydrocarbons such as toluene and xylene. As the solvent, one type may be used alone, or two or more types may be used in combination. When an aqueous solution of hydrochloric acid or the like is used to hydrolyze a trifunctional organosilane or the like, it is preferable to use a solvent in which isopropyl alcohol or the like and ethyl acetate which is a polar solvent are arbitrarily mixed as a co-solvent.

When preparing the composite, a catalyst may be added to the reaction solution in order to accelerate the reaction between the trifunctional organosilane and the acrylic polyol. As the catalyst, tin compounds such as tin chloride (SnCl ₂ , SnCl ₄ ), tin oxychloride (SnOHCl, Sn(OH) ₂ Cl ₂ ), and tin alkoxide are preferable in terms of reactivity and polymerization stability. These catalysts may be added directly at the time of blending each component, or may be added after being dissolved in a solvent such as methanol.

The addition amount of the catalyst is preferably 1/10 to 1/10000, and more preferably 1/100 to 1/2000 in terms of molar ratio with respect to the total amount of the trifunctional organosilane and its hydrolyzate.

Further, in order to improve the liquid stability of the liquid containing the complex, a metal alkoxide or a hydrolyzate thereof may be added.

Examples of the metal alkoxide include tetraethoxysilane [Si(OC ₂ H ₅ ) ₄ ], tripropoxyaluminum [Al(OC ₃ H ₇ ) ₃ ] and the like, a general formula: M(OR) _n (where M is Si, Al , Ti or Zr, and R is an alkyl group such as a methyl group or an ethyl group.). Of these, tetraethoxysilane, tripropoxyaluminum, or a mixture thereof is preferable because it is relatively stable in an aqueous solvent.

The method for obtaining the hydrolyzate of the metal alkoxide is the same as the method for obtaining the hydrolyzate of the trifunctional organosilane. The hydrolysis of the metal alkoxide may be performed simultaneously with the hydrolysis of the trifunctional organosilane, or may be performed separately from the hydrolysis of the trifunctional organosilane.

From the viewpoint of liquid stability, the molar ratio of the trifunctional organosilane and the metal alkoxide is preferably 10:1 to 1:10, and particularly preferably 1:1.

Various additives may be added to the primer layer 12c. Examples of the additives include curing accelerators such as tertiary amines, imidazole derivatives, metal salt compounds of carboxylic acids, quaternary ammonium salts, quaternary phosphonium salts, and antioxidants such as phenol-based, sulfur-based, and phosphite-based antioxidants. Examples include agents, leveling agents, flow control agents, catalysts, crosslinking reaction accelerators, fillers and the like.

The method for forming the primer layer 12c is not particularly limited. For example, a solution obtained by hydrolyzing a trifunctional organosilane in the presence of a catalyst used if necessary, or a solution obtained by mixing an acrylic polyol or an isocyanate compound with a liquid obtained by hydrolyzing a trifunctional organosilane with a metal alkoxide is used as a base material. The method of applying to the film 11 and drying is mentioned. In addition, a solution obtained by adding an isocyanate compound to a liquid obtained by mixing a trifunctional organosilane and an acrylic polyol in a solvent in the presence of a catalyst or a metal alkoxide used as necessary, or a liquid obtained by further performing a hydrolysis reaction is used as a base. A method of applying it to the material film 11 and drying it may be used.

The coating method and the drying method are not particularly limited, and examples thereof include the same methods as those mentioned for forming the gas barrier coating layer 13.

[Laminated film D]
The laminated film D is an example in which the gas barrier film layer 10D is used as the gas barrier film layer, and is the same as the laminated film A except for this point. The gas barrier film layer 10D is formed by laminating a gas barrier coating layer 14 containing a polycarboxylic acid polymer on the adhesive resin layer side of the base film 11 (see FIG. 4).

In the laminated film D, the base film 11, the adhesive resin layer 20 and the thermoplastic resin layer 30 are respectively the base film 11, the adhesive resin layer 20 and the thermoplastic resin layer 30 in the laminated films A to C. Since it is the same, the description thereof will be omitted, and the gas barrier coating layer 14 containing the polycarboxylic acid polymer will be described.

(Gas barrier film layer 14)
The gas barrier coating layer 14 is a layer containing a polycarboxylic acid-based polymer, and by using the polycarboxylic acid-based polymer, the adhesion between the base film 11 and the gas barrier coating layer 14 is improved, and the debris between them is improved. Lamination can be easily suppressed. The polycarboxylic acid polymer means a polymer having two or more carboxyl groups in one molecule.

Examples of the polycarboxylic acid-based polymer include homopolymers of α,β-monoethylenically unsaturated carboxylic acids; copolymers of at least two types of α,β-monoethylenically unsaturated carboxylic acids; α,β -Copolymers of monoethylenically unsaturated carboxylic acid and other ethylenically unsaturated monomers; examples thereof include acidic polysaccharides having a carboxyl group in the molecule such as alginic acid, carboxymethyl cellulose, and pectin. These polycarboxylic acid polymers may be used alone or in combination of two or more.

Examples of the α,β-monoethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like.

Other ethylenically unsaturated monomers copolymerizable with α,β-monoethylenically unsaturated carboxylic acid include, for example, saturated carboxylic acid vinyl esters such as ethylene, propylene and vinyl acetate, alkyl acrylates and alkyl methacrylates. , Alkyl itaconates, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, styrene and the like.

When the polycarboxylic acid-based polymer is a copolymer of α,β-monoethylenically unsaturated carboxylic acid and other ethylenically unsaturated monomer, from the viewpoint of gas barrier property and water resistance, α The copolymerization ratio of the β-monoethylenically unsaturated carboxylic acid is preferably 60 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, particularly preferably 100 mol%.

When the polycarboxylic acid polymer is a polymer consisting only of α,β-monoethylenically unsaturated carboxylic acid, the polymer is acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, croton. It is obtained by polymerizing at least one polymerizable monomer selected from the group consisting of acids. The polymer is preferably a polymer obtained by polymerizing at least one monomer selected from acrylic acid, methacrylic acid and maleic acid, and polyacrylic acid, polymethacrylic acid, polymaleic acid, or a mixture thereof. More preferable.

When the polycarboxylic acid polymer is an acidic polysaccharide, alginic acid is preferably used as a monomer component. The number average molecular weight of the polycarboxylic acid polymer is not particularly limited. The number average molecular weight of the polycarboxylic acid polymer is preferably 2,000 to 10,000,000, more preferably 5,000 to 1,000,000, from the viewpoint of coating properties.

In the gas barrier coating layer 14, another polymer may be mixed with the polycarboxylic acid-based polymer as long as the gas barrier property is not impaired. For example, the gas barrier coating layer 14 may be made of a mixture of a polycarboxylic acid polymer and polyalcohols.

Polyalcohols include low molecular weight compounds having two or more hydroxyl groups in the molecule to alcohol-based polymers. Polyalcohols include polyvinyl alcohol (PVA), sugars and starches. Examples of the low molecular weight compound having two or more hydroxyl groups in the molecule include glycerin, ethylene glycol, propylene glycol, 1,3-propanediol, pentaerythritol, polyethylene glycol, polypropylene glycol and the like.

The degree of saponification of PVA is preferably 95% or more, more preferably 98% or more. The average degree of polymerization of PVA is preferably 300 to 1500. From the viewpoint of compatibility with the polycarboxylic acid-based polymer, it is preferable to use a vinyl alcohol-poly(meth)acrylic acid copolymer containing vinyl alcohol as a main component as the polyalcohols.

Monosaccharides, oligosaccharides and polysaccharides are used as saccharides. These sugars include sugar alcohols such as sorbitol, mannitol, dulcitol, xylitol, and erythritol described in JP-A No. 7-165942, substitution products of sugar alcohols, and sugar alcohol derivatives. Preferred sugars are those that dissolve in water, alcohol, or a mixed solvent of water and alcohol. Starches are included in the above-mentioned polysaccharides. Specific examples of the starches include wheat starch, corn starch, potato starch, tapioca starch, rice starch, sweet potato starch, raw starch (unmodified starch) such as sago starch, and various processed starches. Specific examples of the modified starch include, for example, physically modified starch, enzyme modified starch, chemically modified starch, and graft starch obtained by graft-modifying starch to a monomer. Among these starches, water-soluble processed starch obtained by hydrolyzing potato starch with acid, and sugar alcohol in which the terminal group (aldehyde group) of starch is substituted with a hydroxyl group are preferable. The starches may be hydrous. These starches may be used alone or in combination of two or more.

The mixing ratio (mass ratio) of the polycarboxylic acid polymer and the polyalcohols is preferably 99:1 to 20:80 from the viewpoint of obtaining a packaging container having excellent oxygen gas barrier properties even under high humidity conditions, 95:5 to 40:60 are more preferred, and 95:5 to 50:50 are even more preferred.

For the gas barrier coating layer 14, for example, the coating liquid 1 containing a polycarboxylic acid polymer and a solvent or the coating liquid 2 containing a polycarboxylic acid polymer, a polyalcohol and a solvent is coated on the base film 11. And the solvent is evaporated to dryness. In addition, a coating solution containing a monomer forming a polycarboxylic acid polymer is applied onto the base film 11, and is polymerized by irradiating with an ultraviolet ray or an electron beam to obtain a polycarboxylic acid polymer, which is a gas barrier film layer. Alternatively, a method of forming the gas barrier coating layer 14 as a polycarboxylic acid-based polymer by depositing the monomer on the base film and simultaneously irradiating an electron beam to polymerize the monomer may be used.

The coating liquid 1 is prepared by dissolving or dispersing a polycarboxylic acid polymer in a solvent. The solvent is not particularly limited as long as it can uniformly dissolve or disperse the polycarboxylic acid polymer. Specific examples of the solvent include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and the like. The solvent is preferably a non-aqueous solvent or a mixture of a non-aqueous solvent and water. The concentration of the polycarboxylic acid polymer in the coating liquid 1 is preferably 0.1 to 50% by mass.

The method for obtaining the coating liquid 2 is not particularly limited. Specific examples of the method of obtaining the coating liquid 2 include a method of dissolving each component in a solvent, a method of mixing a solution of each component, a method of polymerizing a monomer containing a carboxyl group in a polyalcohol solution, and optionally after polymerization. Examples include a method of neutralizing with an alkali. Specific examples of the solvent include water, alcohol, and a mixture of water and alcohol. The solid content concentration of the coating liquid 2 is preferably 1 to 30% by mass.

In the coating liquid 1 and the coating liquid 2, other polymers, softeners, plasticizers (excluding low molecular weight compounds having two or more hydroxyl groups in the molecule), stabilizers, etc., as long as the oxygen gas barrier property is not impaired. In addition, an anti-blocking agent, a pressure-sensitive adhesive, an inorganic layered compound such as montmorillonite, etc. may be appropriately added.

From the viewpoint of the oxygen gas barrier property, a compound containing a monovalent and/or divalent metal may be added to the coating liquid 1. Specific examples of the monovalent and/or divalent metal include sodium, potassium, zinc, calcium, magnesium and copper. Specific examples of the compound containing a monovalent and/or divalent metal are sodium hydroxide, zinc oxide, calcium hydroxide and calcium oxide.

The addition amount of the monovalent and/or divalent metal-containing compound to the coating liquid 1 is preferably 0 to 70 mol% and more preferably 0 to 50 mol% based on the carboxyl group of the polycarboxylic acid polymer. preferable.

In order to improve the oxygen gas barrier property, the coating liquid 2 may be applied onto the substrate film and dried to heat-treat the film. In this case, in order to ease the heat treatment conditions, a water-soluble alkali metal compound or a metal salt of an inorganic acid or an organic acid may be appropriately added when the coating liquid 2 is prepared. Specific examples of the metal include alkali metals such as lithium, sodium and potassium.

Specific examples of metal salts of inorganic acids or organic acids include lithium chloride, sodium chloride, potassium chloride, sodium bromide, sodium phosphinate (sodium hypophosphite), disodium hydrogen phosphite, disodium phosphate, Examples thereof include sodium ascorbate, sodium acetate, sodium benzoate, sodium hyposulfite and the like. Among these exemplified metal salts, metal phosphinic acid salts (metal hypophosphite) such as sodium phosphinate (sodium hypophosphite) and calcium phosphinate (calcium hypophosphite) are preferable. The addition amount of the metal salt of an inorganic acid and an organic acid is preferably 0.1 to 40 parts by mass, and more preferably 1 to 30 parts by mass with respect to 100 parts by mass of the solid content in the coating liquid 2.

Specific examples of the alkali metal compound include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. The addition amount of the alkali metal compound is preferably 0 to 30 mol% with respect to the carboxyl group of the polycarboxylic acid polymer in the coating liquid 2.

Examples of the coating method of the coating liquid 1 or the coating liquid 2 include devices such as an air knife coater, a kiss roll coater, a metalling bar coater, a gravure roll coater, a reverse roll coater, a dip coater, a die coater, and a sprayer, or There is a method of using an apparatus combining them.

As a method for evaporating and drying the solvent, for example, a device such as an arch dryer, a straight bath dryer, a tower dryer, a floating dryer, a drum dryer, an infrared dryer, or a combination thereof is used to blow hot air, infrared irradiation, and natural drying. , A method such as drying in an oven.

The thickness of the gas barrier coating layer 14 is preferably 10 μm or less, more preferably 5 μm or less, still more preferably 1 μm or less.

A coating layer containing a zinc compound may be formed on the gas barrier coating layer 14.

Specific examples of the zinc compound include zinc oxide, hydroxide, carbonate, organic acid salt, and inorganic acid salt. As the zinc compound, zinc oxide, zinc hydroxide, zinc carbonate, zinc acetate and zinc phosphate are preferable. Zinc has a low toxicity, and zinc sulfide (white) produced by reacting zinc with hydrogen sulfide causing a retort odor hardly affects the appearance of the packaging container.

The preferred form of the zinc compound is particles. From the viewpoint of coating suitability and dispersibility in a solvent, the average particle size of the zinc compound particles is preferably 5 μm or less, more preferably 1 μm or less, and further preferably 0.1 μm or less.

The content of the zinc compound in the coating layer is preferably 32.7 mg or more as zinc per 1 m ² . When the content of the zinc compound is 32.7 mg or more, the effect of hydrogen sulfide absorbed by the zinc compound is easily perceptually perceived. The content of the zinc compound is more preferably 65.4 mg or more, more preferably 131 mg or more, and particularly preferably 196 mg or more as zinc per 1 m ² . As the content of the zinc compound increases, the retort odor absorption effect increases, but the flavor of the contents may be impaired. For example, when a food having an important flavor derived from a sulfur-containing compound such as a garlic seasoning product is packed in a packaging container containing a large amount of a zinc compound, the flavor of the food may be impaired. Therefore, the content of the zinc compound needs to be appropriately adjusted depending on the contents to be packaged.

The thickness of the coating layer containing the zinc compound is preferably 0.1 to 10 μm, more preferably 0.1 to 2 μm, and even more preferably 0.1 to 1 μm. When the thickness of the coating layer is the lower limit value or more, the thickness of the coating layer is likely to be stably maintained. When the thickness of the coating layer is less than or equal to the upper limit value, the productivity of the coating layer is high and the coating layer is less likely to undergo cohesive failure.

The method of forming the coating layer containing the zinc compound is not particularly limited, and examples thereof include a method of applying a coating agent containing the zinc compound and a solvent or a dispersion medium.

Specific examples of the solvent or the dispersion medium include, for example, water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene. , Hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate and the like. From the viewpoint of coating suitability and manufacturability, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, and water are preferable as the solvent or dispersion medium. These solvents or dispersion media may be used alone or in combination of two or more.

Additives such as resins, surfactants, softeners, stabilizers, film-forming agents, anti-blocking agents, and pressure-sensitive adhesives may be appropriately added to the coating agent.

Examples of the resin include paint resins such as alkyd resin, melamine resin, acrylic resin, nitrified cotton, urethane resin, polyester resin, phenol resin, amino resin, fluororesin, and epoxy resin.

From the viewpoint of dispersibility of the zinc compound, it is preferable to add a dispersant to the coating agent. Specific examples of the dispersant include, for example, acrylamide, acrylic acid, acrylic acid ester, acrylic acid neutralized product, acrylonitrile, adipic acid, adipic acid ester, adipic acid neutralized product, azelaic acid, abietic acid, aminododecanoic acid, Arachidic acid, allylamine, arginine, arginine acid, albumin, ammonia, itaconic acid, itaconic acid ester, itaconic acid neutralized product, ethylene oxide, ethylene glycol, ethylenediamine, oleic acid, kaolin, casein, caprylic acid, caprolactam, xanthan gum, citric acid Acid, glycine, cristobalite, glycerin, glycerin ester, glucose, crotonic acid, silicic acid, saccharose, salicylic acid, cycloheptene, oxalic acid, starch, stearic acid, sebacic acid, cellulose, ceresin, sorbitan fatty acid ester (sorbitan oleate, sorbitan steer) Sorbate, sorbitan permylate, sorbitan behenate, sorbitan laurate), sorbitol, sorbic acid, talc, dextrin, terephthalic acid, dolomite, nitrocellulose, urea, vermiculite, palmitic acid, pinene, phthalic acid, fumaric acid, propionic acid , Propylene glycol, hexamethylenediamine, pectin, behenic acid, benzyl alcohol, benzoic acid, benzoic acid ester, benzoguanamine, pentaerythritol, bentonite, boric acid, polydimethylsiloxane, polyvinyl alcohol, mica, maleic acid, maleic acid ester, maleic acid Acid neutralized products, malonic acid, mannitol, myristic acid, methacrylic acid, methyl cellulose, coconut oil, eugenol, butyric acid, lignocellulose, lysine, malic acid, phosphoric acid, lecithin, rosin, waxes, polymers thereof, and copolymers thereof. Examples thereof include polymers.

From the viewpoint of coating suitability, the content of the zinc compound in the coating agent is preferably 1 to 50% by mass.

The method of applying the coating agent is not particularly limited, and examples thereof include the same methods as those described above in the method of applying the coating liquid 1 or the coating liquid 2.

The method for drying the coating agent after coating is not particularly limited, and examples thereof include the same method as the method for drying the coating liquid 1 or the coating liquid 2 after coating. The drying conditions are also not particularly limited. The drying temperature is preferably 40 to 350°C, more preferably 45 to 325°C, and further preferably 50 to 300°C. The drying time is preferably 0.5 seconds to 10 minutes, more preferably 1 second to 5 minutes, still more preferably 1 second to 1 minute.

[Laminated film E]
The laminated film E is an example in which the gas barrier film layer 10E is used as the gas barrier film layer, and is the same as the laminated film A except for this point. The gas barrier film layer 10E includes a gas barrier coating layer 15 containing a phosphorus-based gas barrier composite structure formed by a reaction of a compound of a polyvalent metal and a phosphorus compound, and the adhesive resin layer 20 of the base film 11. It is laminated on the side (see FIG. 5).

Also in this laminated film E, the base film 11, the adhesive resin layer 20, and the thermoplastic resin layer 30 are the same as the base film 11, the adhesive resin layer 20, and the thermoplastic resin layer 30 in the laminated films A to D, respectively. Since it is the same, the description thereof will be omitted, and the gas barrier coating layer 15 containing the phosphorus-based gas barrier composite structure will be described.

(Gas barrier film layer 15)
The gas barrier film layer 15 may be a single layer of a layer containing a reaction product of a metal oxide and a phosphorus compound, or may be a multilayer.

Examples of the metal atom constituting the metal oxide include a metal atom having a valence of 2 or more (for example, 2 to 4 or 3 to 4). Examples of specific metal atoms include Mg, Ca, Zn, Al, Si, Ti, and Zr. In particular, it is preferable to use Al as the metal atom.

The metal oxide can be synthesized as a hydrolyzed condensate of the compound by hydrolyzing and condensing a compound having a hydrolyzable characteristic group bonded to a metal atom as a raw material.

As a method of hydrolyzing and condensing the compound, a liquid phase synthesis method, specifically, a sol-gel method can be adopted.

The synthesized metal oxide becomes fine particles. The shape of the metal oxide particles is not particularly limited, and examples thereof include a spherical shape, a flat shape, a polyhedral shape, a fibrous shape, and a needle shape. It is preferable that the particles have a fibrous or acicular shape because the barrier properties and the hot water resistance are further excellent.

The size of the metal oxide particles is also not particularly limited, and those of nanometer size to submicron size can be used. The average particle size of the metal oxide is preferably 1 to 100 nm because it is more excellent in barrier properties and transparency.

The phosphorus compound is one having one or more sites capable of reacting with a metal oxide, such as phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid and their derivatives. Examples of the site capable of reacting include a halogen atom directly bonded to a phosphorus atom and an oxygen atom directly bonded to a phosphorus atom.

Since a hydroxyl group is usually present on the surface of a metal atom, a halogen atom or an oxygen atom can be bonded to the hydroxyl group by causing a condensation reaction (hydrolysis condensation reaction). The reaction product of the metal oxide and the phosphorus compound may have a structure in which the particles of the metal oxide are bonded to each other through the phosphorus atom derived from the phosphorus compound. Specifically, a functional group (for example, a hydroxyl group) existing on the surface of a metal oxide and a site capable of reacting with metal oxidation in a phosphorus compound (for example, a halogen atom directly bonded to a phosphorus atom or a direct bond to a phosphorus atom). The resulting oxygen atom) causes a condensation reaction (hydrolysis condensation reaction) and bonds.

The reaction product is obtained, for example, by applying a coating liquid containing a metal oxide and a phosphorus compound on the surface of the base material and heat-treating the formed coating film. The particles of the metal oxide proceed with a reaction in which the particles are bound to each other via the phosphorus atom derived from the phosphorus compound.

The temperature of the heat treatment is preferably 110°C or higher, more preferably 120°C or higher, further preferably 140°C or higher, and particularly preferably 170°C or higher. When the heat treatment temperature is at least the lower limit value, the reaction time is shortened and the productivity is improved. The heat treatment temperature is preferably 220° C. or lower, more preferably 190° C. or lower, though it varies depending on the type of the base film layer 11.

The heat treatment can be carried out in the air, a nitrogen atmosphere, an argon atmosphere, or the like. The heat treatment time is preferably 0.1 seconds to 1 hour, more preferably 1 second to 15 minutes, and further preferably 5 to 300 seconds.

The gas barrier film layer 15 includes polyvinyl alcohol, partially saponified polyvinyl acetate, polyethylene glycol, polyhydroxyethyl (meth)acrylate, polysaccharides such as starch, polysaccharide derivatives derived from polysaccharides, polyacrylic acid, and polyacrylic acid. Methacrylic acid, (poly)acrylic acid/methacrylic acid, and salts thereof, ethylene-vinyl alcohol copolymer, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride alternating copolymer A polymer, an ethylene-acrylic acid copolymer, a saponification product of an ethylene-ethyl acrylate copolymer, or the like may be included.

Gas barrier coating layer 15 is preferably a wave number infrared absorption of the infrared absorption spectrum in the range of 800～1400Cm ^-1 becomes maximum is in the range of 1080~1130cm ^-1.

When the absorption peak appears as the absorption peak of the maximum absorption wave number in the region of 800 to 1400 cm ^-1 , where absorption derived from the bond between various atoms and oxygen atoms is generally seen, a more excellent barrier property and hot water resistance are obtained. Expressed. Examples of the metal atom forming the metal oxide that satisfies this requirement include Al.

The upper limit of the thickness of the gas barrier coating layer 15 is preferably 4.0 μm, more preferably 2.0 μm, further preferably 1.0 μm, and particularly preferably 0.9 μm. By thinning the gas barrier film layer 15, the gas barrier film layer 1 at the time of processing such as printing and laminating
The dimensional change of 0C can be suppressed low. Furthermore, the flexibility of the gas barrier film layer 10C is increased, and the mechanical characteristics thereof can be made closer to the mechanical characteristics of the base film layer 11 itself.

The lower limit of the thickness of the gas barrier coating layer 15 is preferably 0.1 μm, more preferably 0.2 μm.

[Packing container]
The packaging container of the present invention is a packaging container obtained by bag-making the laminated film of the present invention. The packaging container of the present invention can adopt known aspects except that the laminated film of the present invention is used. As the packaging container of the present invention, for example, two rectangular laminated films are stacked so that the thermoplastic resin layers are in contact with each other, and the four sides thereof are heat-sealed, and the rectangular laminated film is in contact with the thermoplastic resin layers. As described above, a packaging container or the like, which is folded in two and heat-sealed on three sides, can be given. In addition, the rectangular laminated film is formed into a tubular shape so that the thermoplastic resin layer is on the inner side, and the thermoplastic resin layers at both side end portions are combined and heat-sealed to form a spine pasting portion, and the upper and lower portions thereof are heated. A pillow-shaped packaging container that is sealed and sealed may be used.

(Example 1)
This example is an example of the laminated film B shown in FIG.

That is, as the gas barrier film layer 10B, a film having the metal oxide vapor deposition layer 12 and the gas barrier coating layer 13 on the base film 11 was used. The base film 11 is a biaxially stretched polyester film. The metal oxide vapor deposition layer 12 was formed by vapor deposition of aluminum oxide on the base film 11. The gas barrier coating layer 13 was formed by applying a coating liquid containing a mixture of tetraalkoxysilane, polyvinyl alcohol and a silane coupling agent onto the metal oxide vapor deposition layer 12, heating and drying the coating to cure it.

In addition, as the adhesive resin forming the adhesive resin layer 20, maleic acid graft-modified polypropylene containing hexagonal boron nitride was used. When differential scanning calorimetry (DSC) was performed on this maleic acid graft-modified polypropylene, melting point peaks were shown at 104°C, 140°C, and 155°C. Its density is 0.88 g/cm ³ , and its melt flow rate is 8.2 g/10 min. The blending amount of boron nitride in the adhesive resin is 2% by mass.

Further, as a resin forming the thermoplastic resin layer 30, a polypropylene resin manufactured by Japan Polypro Co., Ltd. was used. This polypropylene resin has a melting point of 138° C., a density of 0.89 g/cm ³ and a melt flow rate of 18 g/10 min.

As the sealant film, a 70 μm thick unstretched polypropylene film for retort was used.

Then, between the gas barrier film layer 10 and the sealant film, the adhesive resin and the thermoplastic resin are melt-extruded and pressed by a heating roll, so that the gas barrier film layer 10 and the adhesive resin layer 20, The laminated film B of Example 1 was manufactured by stacking the thermoplastic resin layer 30 and the sealant film, and using a heating platen instead of the heating roll and pressing with the heating platen. The thickness of each of the adhesive layer 20 and the thermoplastic resin layer 30 is 10 μm.

In addition, the temperature of the heating plate is 130°C, 140°C, 150°C, 160°C, 170°C, 180°C.
, 190° C. and 200° C., to produce each laminated film. The pressing pressure is 0.2 MPa, and the pressing time is 1 second.

(Example 2)
A laminated film B of Example 2 was produced in the same manner as in Example 1 except that the content of boron nitride in the adhesive resin was 3% by mass.

(Example 3)
A laminated film B of Example 3 was produced in the same manner as in Example 1 except that the blending amount of boron nitride in the adhesive resin was 5% by mass.

(Example 4)
A laminated film B of Example 4 was produced in the same manner as in Example 1 except that the content of boron nitride in the adhesive resin was 6% by mass.

(Comparative example)
A laminated film B of a comparative example was produced in the same manner as in Example 1 except that the content of boron nitride in the adhesive resin was 0% by mass.

(Evaluation)
The adhesive strength of the laminated films of Examples 1 to 4 and Comparative Example was measured. The results are shown in Table 1.

As can be seen from these results, the laminated film of the present invention can be bonded with high adhesive strength at a low heating roll temperature of 130° C. even when the blending amount of boron nitride is 2% by mass (Example 1). it can.

In addition, the highest adhesive strength is obtained when the compounding amount of boron nitride is 3 to 5 mass% (Examples 2 to 3). Even if the compounding amount is larger than this (Example 4), the adhesive strength is not improved.

Further, as the temperature of the heating roll becomes higher, the adhesive strength becomes higher, but if it exceeds 170° C., a large difference due to the temperature of the heating roll does not occur.

AE: Laminated films 10A to 10E: Gas barrier film layer 11: Substrate film 12: Metal oxide deposition layer 12c: Primer layer 13: Gas barrier coating layer composed of silicon-based gas barrier composite structure 14: Polycarboxylic acid type Gas barrier coating layer containing polymer 15: Gas barrier coating layer containing phosphorus-based gas barrier composite structure 20: Adhesive resin layer 30: Thermoplastic resin layer

Claims (12)

In a laminated film in which a gas barrier film layer and a thermoplastic resin layer are laminated via a melted adhesive resin,
A laminated film, wherein the adhesive resin contains maleic acid graft modified polypropylene containing boron nitride. The laminated film according to claim 1,
The laminated film, wherein the compounding amount of boron nitride in the adhesive resin is 3 to 5% by mass. The laminated film according to claim 1 or 2,
The laminated film, wherein the gas barrier film layer is formed by laminating a metal oxide vapor deposition layer on the adhesive resin layer side of a base film. The laminated film according to claim 3,
A gas barrier coating layer is laminated on the vapor deposition layer,
A laminated film, wherein the gas barrier coating layer is composed of a silicon-based gas barrier composite structure. The laminated film according to claim 4,
A laminated film, wherein the silicon-based gas barrier composite structure is a silicon-based gas barrier composite structure formed by reacting the following compounds 1 to 3.
Compound 1: A silicon compound represented by the general formula Si(OR ¹ ) ₄ (R ¹ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ) or a hydrolyzate thereof.
Compound 2: Silicon represented by the general formula (R ² Si(OR ³ ) ₃ ) _n (R ² represents an organic functional group, R ³ represents CH ₃ , C ₂ H ₅ , or C ₂ H ₄ OCH ₃ ). A compound or a hydrolyzate thereof.
Compound 3: Water-soluble polymer. The laminated film according to any one of claims 3 to 5,
A primer layer is disposed between the base film and the vapor deposition layer,
A laminated film, wherein the primer layer is a silicon-based composite structure formed by reacting the following compounds 4 to 6.
Compound 4: General formula R ⁴ Si(OR ⁵ ) ₃ (R ⁴ : alkyl group, vinyl group, alkyl group having isocyanate group, alkyl group having glycidoxy group or alkyl group having epoxy group, R ⁵ : alkyl group A trifunctional organosilane represented by the formula) or a hydrolyzate thereof.
Compound 5: Acrylic polyol.
Compound 6: Isocyanate compound. The laminated film according to any one of claims 3 to 6,
A laminated film, wherein the surface of the substrate film on which the vapor deposition layer is formed is plasma-treated. The laminated film according to claim 1 or 2,
A laminated film, wherein the gas barrier film layer is formed by laminating a gas barrier film layer containing a polycarboxylic acid polymer on the adhesive resin layer side of a base film. The laminated film according to claim 1 or 2,
The gas barrier film layer, a gas barrier coating layer containing a phosphorus-based gas barrier composite structure formed by the reaction of a compound of a polyvalent metal and a phosphorus compound, is laminated on the adhesive resin layer side of the substrate film. A laminated film characterized by being configured as follows. The manufacturing method of the laminated film in any one of Claims 1-9. A packaging container formed by bag-making the laminated film according to claim 1. The method for manufacturing the packaging container according to claim 11.

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