JP4876399B2 - Laminate film - Google Patents

Description

  The present invention relates to a laminate film. More specifically, the present invention relates to a laminate film used for packaging materials such as foods and pharmaceuticals for the purpose of preserving contents using an adhesive excellent in shielding various gases.

  In recent years, composite flexible films combining different kinds of polymer materials have become mainstream as packaging materials for reasons such as strength, product protection, workability, and advertising effects due to printing. Such a composite film is generally composed of a thermoplastic film layer as an outer layer having a role of protecting a product and a thermoplastic film layer as a sealant layer, and these are bonded to the laminate film layer. A dry laminating method in which a sealant layer is adhered by applying a coating agent, and an extrusion laminating method in which an anchor coating agent is applied to a laminating film layer and a plastic film that becomes a melted sealant layer is pressure-bonded and laminated into a film as necessary. It is done.

  The adhesives used in these methods are generally two-component polyurethane adhesives composed of a main agent having an active hydrogen group such as a hydroxyl group and a curing agent having an isocyanate group, because of its high adhesive performance. (See Patent Documents 1 and 2).

However, since these two-component polyurethane adhesives generally do not have a fast curing reaction, they are accelerated by aging over a long period of 1 to 5 days after bonding to ensure sufficient adhesion. Had to do. In addition, since a curing agent having an isocyanate group is used, when an unreacted isocyanate group remains after curing, the residual isocyanate group reacts with moisture in the atmosphere to generate carbon dioxide. There were problems such as the generation of bubbles.
On the other hand, as a method for solving these problems, polyurethane adhesives and epoxy laminate adhesives have been proposed (see Patent Documents 3 to 4).

However, the gas barrier properties of each of the above-mentioned polyurethane-based adhesives and epoxy-based laminate adhesives are not high, so when packaging materials require gas barrier properties, PVDC coating layers and polyvinyl alcohol (PVA) coating layers Flexible polymer film layer to be used as various gas barrier layers and sealant layers, such as ethylene-vinyl alcohol copolymer (EVOH) film layer, metaxylylene adipamide film layer, inorganic vapor deposited film layer deposited with alumina, silica, etc. It is necessary to laminate separately the layer which plays the role of adhesion | attachment, such as an adhesive bond layer and an anchor coat layer (refer patent document 5), and it suffers from the manufacturing cost of a laminate film, and the work process in lamination. Met.
As a method for solving these problems, an adhesive for gas barrier laminates has been proposed (see Patent Document 6).
Japanese Patent Laid-Open No. 5-51574 JP-A-9-316422 JP 2000-154365 A WO99 / 60068 pamphlet Japanese Patent Laid-Open No. 10-71664 JP 2002-256208 A

However, the gas barrier laminating adhesive described above may cause the peeling of the adhesive layer on the ink layer and the ink cohesive strength to be reduced when printing is performed on the substrate on which the adhesive is applied. There was a problem that the laminate strength of the film was lowered.
An object of the present invention is to solve the above problems and provide a gas barrier laminate film having excellent laminate strength even when printing is performed on a substrate.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a specific resin to the ink layer of the base material, and then laminated a sealant film using a gas barrier adhesive, thereby providing a gas barrier property. It has been found that a laminate film having excellent adhesiveness can be obtained economically and with good workability, and has led to the present invention.

  That is, the present invention includes at least one resin selected from a base material, an ink layer, a polyurethane resin, a vinyl chloride-vinyl acetate copolymer resin, a rosin resin, a polyamide resin, and a chlorinated olefin resin ( A laminate film in which the layer consisting of A), the adhesive layer, and the sealant layer are laminated in this order, and the adhesive forming the adhesive layer is mainly an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent. A laminated film characterized by comprising 40% by weight or more of a skeleton structure represented by the formula (1) in a cured epoxy resin obtained by curing the epoxy resin composition. Is.

  The laminate film of the present invention is excellent in adhesiveness in addition to gas barrier properties, and is applied to various uses as a non-halogen gas barrier material. In addition, the laminate film has an excellent laminate strength even when printing is performed on the substrate, and is useful.

  The laminate film of the present invention comprises at least a substrate, an ink layer, a resin (A) layer, an adhesive layer, and a sealant layer, which are laminated in this order. The material layer is used on the outer surface of the bag, and the sealant layer is used on the inner surface of the bag.

Examples of the base material in the present invention include polyester films such as polyethylene terephthalate and polybutylene terephthalate, polyamide films such as nylon 6, nylon 6,6, metaxylene adipamide (N-MXD6), low density polyethylene, high Polyolefin film such as density polyethylene, linear low density polyethylene, polypropylene, polyacrylonitrile film, poly (meth) acrylic film, polystyrene film, polycarbonate film, ethylene-vinyl alcohol copolymer (EVOH) film, Polyvinyl alcohol film, papers such as cartons, metal foils such as aluminum and copper, and various materials used as these substrates. Polyvinylidene chloride (PVDC) resin, polyvinyl alcohol resin, ethylene- Films coated with various polymers such as vinyl acid copolymer saponified resins, acrylic resins, films deposited with various inorganic compounds or metals such as silica, alumina, and aluminum, films with dispersed inorganic fillers, etc. A film having an oxygen scavenging function can be used. Moreover, an inorganic filler can be disperse | distributed also about the various polymers to coat. Examples of inorganic fillers include silica, alumina, mica, talc, aluminum flakes, and glass flakes. Layered silicates such as montmorillonite are preferred, and dispersion methods thereof include, for example, extrusion kneading and mixing into resin solutions. A conventionally known method such as a dispersion method can be used. Examples of methods for imparting oxygen scavenging functions include hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol and other low molecular organic compounds that react with oxygen, cobalt, manganese, nickel, iron And a method of using a composition containing a transition metal compound such as copper at least in part.
The thickness of these film materials is about 10 to 300 μm, preferably about 10 to 100 μm, and in the case of a plastic film, it may be stretched in a uniaxial or biaxial direction.
In the present invention, the film material such as polyolefin and polyester is laminated (for example, an adhesive layer and a layer other than the base material, ink layer, resin (A), adhesive layer and sealant layer). Or between sealant layers). When laminating various materials, a plurality of adhesive layers may be provided. Moreover, you may use together adhesive agents other than the adhesive agent in this invention.

  The ink layer in the present invention is composed of organic pigments such as azo, phthalocyanine, and isoindolinone; inorganic pigments such as titanium dioxide, carbon black, and calcium carbonate; polyurethane resins, polyurethane urea resins, acrylic modified urethane resins, and acrylic modified urethanes. Polyurethane resins such as urea resins; vinyl chloride-vinyl acetate copolymer resins; rosin resins such as rosin-modified maleic resins; polyamide resins; binder resins such as chlorinated olefin resins such as chlorinated polypropylene resins; water It is formed by ink that has been used for printing layers on conventional polymer films formed from solvents such as methanol, 2-propanol, ethyl acetate, methyl ethyl ketone, and toluene. For the formation of the ink layer, general printing equipment that has been used for printing on conventional polymer films such as a gravure printing machine, a flexographic printing machine, and an offset printing machine can be applied. The ink layer on the substrate may be continuous (full-surface printing) or intermittent (partial printing).

Examples of the resin (A) in the present invention include polyurethane resins such as polyurethane resins, polyurethane urea resins, acrylic modified urethane resins, and acrylic modified urethane urea resins; vinyl chloride-vinyl acetate copolymer resins; rosin modified maleic acid resins and the like. Examples thereof include rosin resins; polyamide resins; chlorinated olefin resins such as chlorinated polypropylene resins. As the resin (A), at least one selected from a polyurethane resin, a vinyl chloride-vinyl acetate copolymer resin, a rosin resin, a polyamide resin, and a chlorinated olefin resin is used. In view of strength, polyurethane resins and / or vinyl chloride-vinyl acetate copolymer resins are preferred. These resins can be used alone or as a mixture. A layer made of the resin (A) can be formed by dissolving these resins in a solvent such as water, methanol, 2-propanol, ethyl acetate, methyl ethyl ketone, and toluene and applying the resin by a gravure method, a roll coating method, or the like. it can. For the formation of the layer made of the resin (A), general printing equipment that has been used for printing on conventional polymer films such as a gravure printing machine, a flexographic printing machine, and an offset printing machine can be similarly applied.
Here, extender pigments may be included in the resin (A). Moreover, it is preferable that resin (A) is resin of the same system as the binder resin of the ink which forms the said ink layer. In this case, a resin varnish having the same composition as the ink marketed by each ink manufacturer under the trade name such as medium can be used.
In addition, although the layer which consists of resin (A) needs to be formed at least on all the ink layers, you may form on the base material in which the ink layer is not formed.

  The thickness of the layer made of the resin (A) is 0.01 to 10 μm, preferably 0.1 to 5 μm. If it is less than 0.01 μm, it is difficult to exhibit sufficient adhesion, while if it exceeds 10 μm, it becomes difficult to form a resin layer having a uniform thickness.

  When a curable resin (A) is used, it may be a one-component curing type or a two-component curing type, but in the case of a two-component curing type, it is desirable to use polyisocyanate as a curing agent. Specific examples include aromatic polyisocyanates such as toluene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), or aliphatic polyisocyanates such as hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and xylene diisocyanate (XDI). It is done.

  In addition, an additive may be included in the resins in order to impart other functionality to the layer made of the resin (A). For example, wax, a dispersant, an antistatic agent, a surface modifier, etc. can be used for improving friction resistance, blocking prevention, slipping, heat resistance, antistatic, etc., which can be appropriately selected and used. .

  As the sealant layer in the present invention, it is preferable to use a flexible polymer film, and a polyolefin film such as a polyethylene film, a polypropylene film or an ethylene-vinyl acetate copolymer is selected in consideration of the expression of good heat sealability. It is preferable to do. The thickness of these films is practically about 10 to 300 μm, preferably about 10 to 100 μm, and various surface treatments such as flame treatment and corona discharge treatment may be performed on the surface of the film.

In the laminate film of the present invention, the adhesive forming the adhesive layer is mainly composed of an epoxy resin composition composed of an epoxy resin and an epoxy resin curing agent, and the epoxy resin cured product obtained by curing the epoxy resin composition. The skeleton structure of the above formula (1) is contained in an amount of 40% by weight or more, preferably 45% by weight or more, more preferably 50% by weight or more. When the skeleton structure of the formula (1) is contained at a high level in the cured epoxy resin, a high gas barrier property is exhibited. According to the present invention, it is also possible to obtain an epoxy resin cured product having an oxygen barrier property of an oxygen permeability coefficient of 1.0 ml · mm / m ² · day · MPa (23 ° C., 60% RH) or less. Below, the epoxy resin and epoxy resin hardening | curing agent which are the main components of an epoxy resin composition are demonstrated.

  The epoxy resin in the present invention may be any of an aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound. However, in consideration of the expression of high gas barrier properties, the aromatic moiety is located in the molecule. Is preferable, and an epoxy resin including the skeleton structure of the above formula (1) in the molecule is more preferable. Specifically, an epoxy resin having a glycidylamine moiety derived from metaxylylenediamine, an epoxy resin having a glycidylamine moiety derived from 1,3-bis (aminomethyl) cyclohexane, and a glycidylamine derived from diaminodiphenylmethane An epoxy resin having a glycidylamine moiety and / or a glycidyl ether moiety derived from paraaminophenol, an epoxy resin having a glycidyl ether moiety derived from bisphenol A, and a glycidyl ether moiety derived from bisphenol F Epoxy resin having glycidyl ether moiety derived from phenol novolac, epoxy resin having glycidyl ether moiety derived from resorcinol Fats can be used, but among them, epoxy resin having glycidylamine moiety derived from metaxylylenediamine, epoxy resin having glycidylamine moiety derived from 1,3-bis (aminomethyl) cyclohexane, derived from bisphenol F Preferred are epoxy resins having a glycidyl ether moiety and epoxy resins having a glycidyl ether moiety derived from resorcinol.

  Further, it is more preferable to use an epoxy resin having a glycidyl ether moiety derived from bisphenol F or an epoxy resin having a glycidyl amine moiety derived from metaxylylenediamine as a main component, and derived from metaxylylenediamine. It is particularly preferable to use an epoxy resin having a glycidylamine moiety as a main component.

  Moreover, in order to improve various performances such as flexibility, impact resistance, and moist heat resistance, the above-mentioned various epoxy resins can be mixed and used at an appropriate ratio.

The epoxy resin in the present invention is obtained by reaction of various alcohols, phenols and amines with epihalohydrin. For example, an epoxy resin having a glycidylamine moiety derived from metaxylylenediamine can be obtained by adding epichlorohydrin to metaxylylenediamine.
Here, the glycidylamine moiety comprises a mono-, di-, tri- and / or tetra-glycidylamine moiety that can replace the four hydrogen atoms of the diamine in xylylenediamine. The ratio of mono-, di-, tri- and / or tetra-glycidylamine moieties can be varied by changing the reaction ratio of metaxylylenediamine to epichlorohydrin. For example, an epoxy resin mainly having a tetraglycidylamine moiety can be obtained by addition reaction of about 4 times mole of epichlorohydrin to metaxylylenediamine.

The epoxy resin is an excess of epihalohydrin with respect to various alcohols, phenols and amines in the presence of an alkali such as sodium hydroxide, 20 to 140 ° C., preferably 50 to 120 ° C. in the case of alcohols and phenols, amine In the case of a kind, it is synthesized by reacting at a temperature of 20 to 70 ° C. and separating the produced alkali halide.
The number average molecular weight of the produced epoxy resin varies depending on the molar ratio of epihalohydrin to various alcohols, phenols and amines, but is about 80 to 4000, preferably about 200 to 1000, preferably about 200 to 500. It is more preferable.

The epoxy resin curing agent in the present invention may be any of an aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound, such as polyamines, phenols, acid anhydrides, or carboxylic acids. Any commonly used epoxy resin curing agent can be used. These epoxy resin curing agents can be selected according to the use application of the laminate film and the required performance in the application.
Specifically, polyamines include aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, aliphatic amines having an aromatic ring such as metaxylylenediamine and paraxylylenediamine, 1,3- Examples include alicyclic amines such as bis (aminomethyl) cyclohexane, isophoronediamine, norbornanediamine, and aromatic amines such as diaminodiphenylmethane and metaphenylenediamine.
Also, reaction products with epoxy resins or monoglycidyl compounds made from these polyamines, reaction products with alkylene oxides having 2 to 4 carbon atoms, reaction products with epichlorohydrin, these polyamines A reaction product with a polyfunctional compound having at least one acyl group capable of forming an amide group site by reaction with, an oligomer with an amide group site formed by reaction with these polyamines A reaction product of a polyfunctional compound having at least one acyl group and a monovalent carboxylic acid and / or a derivative thereof can be used.

Examples of phenols include multi-substituent monomers such as catechol, resorcinol and hydroquinone, and resole type phenol resins.
Acid anhydrides or carboxylic acids include aliphatic acid anhydrides such as dodecenyl succinic anhydride and polyadipic anhydride, and alicyclic acid anhydrides such as (methyl) tetrahydrophthalic anhydride and (methyl) hexahydrophthalic anhydride. Aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and carboxylic acids thereof can be used.

In consideration of the expression of high gas barrier properties, an epoxy resin curing agent containing an aromatic moiety in the molecule is preferred, and an epoxy resin curing agent containing the skeleton structure of the above formula (1) in the molecule is more preferred.
Specifically, metaxylylenediamine or paraxylylenediamine, reaction products with epoxy resins or monoglycidyl compounds using these as raw materials, reaction products with alkylene oxides having 2 to 4 carbon atoms, epichlorohydrin Reaction products with these polyamines, reaction products with polyfunctional compounds having at least one acyl group that can form oligomers by reaction with these polyamines, and with these polyamines It is more preferable to use a reaction product of a polyfunctional compound having at least one acyl group and a monovalent carboxylic acid and / or a derivative thereof, which can form an amide group site by the reaction of preferable.

When considering high gas barrier properties and good adhesiveness, the following reaction products (A) and (B) or reactions (A), (B), and (C) are used as epoxy resin curing agents. It is particularly preferred to use the product.
(A) Metaxylylenediamine or paraxylylenediamine
(B) A polyfunctional compound having at least one acyl group capable of forming an amide group site by reaction with a polyamine to form an oligomer
(C) C1-C8 monovalent carboxylic acid and / or derivative thereof

  Examples of the polyfunctional compound having at least one acyl group that can form an amide group site by reaction with the (B) polyamine to form an oligomer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, succinic acid, Carboxylic acids such as malic acid, tartaric acid, adipic acid, isophthalic acid, terephthalic acid, pyromellitic acid, trimellitic acid and their derivatives such as esters, amides, acid anhydrides, acid chlorides, etc., especially acrylic acid Methacrylic acid and derivatives thereof are preferred.

  In addition, monovalent carboxylic acids having 1 to 8 carbon atoms such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, glycolic acid, benzoic acid, and derivatives thereof such as esters, amides, acid anhydrides, acid chlorides, etc. The polyfunctional compound may be used in combination with the starting polyamine. The amide group site introduced by the reaction has a high cohesive force, and the presence of the amide group site in a high proportion in the epoxy resin curing agent provides higher oxygen barrier properties and better adhesive strength.

  The reaction molar ratio of (A) and (B) or (A), (B), and (C) is the reactive functionality contained in (B) with respect to the number of amino groups contained in (A). The ratio of the number of groups, or the ratio of the total number of reactive functional groups contained in (B) and (C) to the number of amino groups contained in (A) is in the range of 0.3 to 0.97 Is preferred. When the ratio is less than 0.3, a sufficient amount of amide groups are not generated in the epoxy resin curing agent, and a high level of gas barrier properties and adhesiveness are not exhibited. Moreover, the ratio of the volatile molecule which remains in the epoxy resin curing agent is increased, which causes odor generation from the obtained cured product. Moreover, since the ratio of the hydroxyl group produced | generated by reaction of an epoxy group and an amino group in the hardening reaction material becomes high, it becomes a factor by which oxygen barrier property in a high humidity environment falls remarkably. On the other hand, in the range higher than 0.97, the amount of amino groups reacting with the epoxy resin is reduced, and excellent impact resistance and heat resistance are not exhibited, and the solubility in various organic solvents or water is lowered. When particularly considering the high gas barrier property, high adhesion, suppression of odor generation, and high oxygen barrier property in a high humidity environment of the obtained cured product, the molar ratio of the polyfunctional compound to the polyamine component is 0.6. A range of ˜0.97 is more preferable. In consideration of the expression of a higher level of adhesiveness, it is preferable that the epoxy resin curing agent in the present invention contains at least 6% by weight of an amide group based on the total weight of the curing agent.

  The laminate film produced using the adhesive in the present invention preferably has a laminate strength of 30 g / 15 mm or more, and 40 g / 15 mm or more immediately after lamination (before aging) at a peeling speed of 300 mm / min. Is more preferably 50 g / 15 mm or more. When the laminate strength is not sufficient, problems such as tunneling of the laminate film and winding deviation at the time of winding the film occur.

In consideration of the expression of high shear strength, for example, at least 1 that can form an amide group site by forming an amide group site by reacting an epoxy resin curing agent such as metaxylylenediamine or paraxylylenediamine with the polyamine. The reaction ratio of the reaction product with the polyfunctional compound having one acyl group is 0.6 to 0.97, preferably 0.8 to 0.97, particularly preferably molar ratio of the polyfunctional compound to the polyamine component. Is preferably in the range of 0.85 to 0.97, and it is preferable to use an epoxy resin curing agent in which the average molecular weight of the oligomer as the reaction product is increased.
A more preferred epoxy resin curing agent is a reaction product of metaxylylenediamine and acrylic acid, methacrylic acid and / or derivatives thereof. Here, the reaction molar ratio of acrylic acid, methacrylic acid and / or derivatives thereof to metaxylylenediamine is preferably in the range of 0.8 to 0.97.

About the compounding ratio of the epoxy resin and the epoxy resin curing agent which are the main components of the adhesive in the present invention, generally in the standard compounding range when producing an epoxy resin cured product by reaction of the epoxy resin and the epoxy resin curing agent. It may be. Specifically, the ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin is in the range of 0.5 to 5.0. If the range is less than 0.5, the remaining unreacted epoxy group causes the gas barrier property of the resulting cured product to decrease, and if it is greater than 5.0, the remaining unreacted amino group results in the resulting cured product. It becomes a cause of lowering the heat and heat resistance. When the gas barrier property and heat-and-moisture resistance of the obtained cured product are particularly taken into consideration, the range of 0.8 to 3.0 is more preferable, and the range of 0.8 to 1.8 is particularly preferable.
In addition, when considering the expression of a high oxygen barrier property in a high humidity environment of the resulting cured product, the ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin is 0.8. A range of ~ 1.4 is preferred.

  In the adhesive according to the present invention, if necessary, a thermosetting resin composition such as a polyurethane resin composition, a polyacrylic resin composition, or a polyurea resin composition may be used as long as the effects of the present invention are not impaired. You may mix.

  The adhesive in the present invention may contain a wetting agent such as silicon or an acrylic compound, if necessary, to help wet the surface of various materials during application. Suitable wetting agents include BYK331, BYK333, BYK347, BYK348, BYK354, BYK380, BYK381 available from Big Chemie. When adding these, the range of 0.01 weight%-2.0 weight% is preferable on the basis of the total weight of an epoxy resin composition.

  In the present invention, a tackifier such as a xylene resin, a terpene resin, a phenol resin, or a rosin resin may be added as necessary in order to improve the adhesiveness to various materials immediately after coating. When adding these, the range of 0.01 weight%-5.0 weight% is preferable on the basis of the total weight of an epoxy resin composition.

Moreover, in order to improve various performances such as gas barrier properties, impact resistance, and heat resistance of the adhesive layer formed by the adhesive in the present invention, silica, alumina, mica, talc, aluminum flakes, Inorganic fillers such as glass flakes may be added.
In consideration of the transparency of the film, it is preferable that such an inorganic filler has a flat plate shape. When adding these, the range of 0.01 weight%-10.0 weight% is preferable on the basis of the total weight of an epoxy resin composition.

  Moreover, you may add the compound etc. which have an oxygen capture | acquisition function to the adhesive agent in this invention as needed. Examples of the compound having an oxygen scavenging function include low molecular organic compounds that react with oxygen such as hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol, cobalt, manganese, nickel, iron, Examples include transition metal compounds such as copper.

  Furthermore, in order to improve the adhesiveness of the adhesive layer formed by the adhesive in the present invention, a coupling agent such as a silane coupling agent or a titanium coupling agent may be added to the adhesive. When adding these, the range of 0.01 weight%-5.0 weight% is preferable on the basis of the total weight of an epoxy resin composition.

  The adhesive in the present invention is characterized by having high gas barrier properties in addition to suitable adhesive performance, and exhibits high gas barrier properties in a wide range from low humidity conditions to high humidity conditions. From this, the laminate film using the adhesive in the present invention is a PVDC coat layer, a polyvinyl alcohol (PVA) coat layer, an ethylene-vinyl alcohol copolymer (EVOH) film layer, a metaxylylene adipamide film layer, A very high level of gas barrier properties is exhibited without using a commonly used gas barrier material such as an inorganic vapor deposition film layer on which alumina or silica is vapor-deposited. Furthermore, the gas barrier properties of the resulting film can be significantly improved by using these conventional gas barrier materials and sealant materials together as an adhesive.

  Gas barriers such as ethylene-vinyl alcohol copolymer (EVOH) film, polyvinyl alcohol film, polyvinyl alcohol coated film, polyvinyl alcohol coated film in which inorganic filler is dispersed, metaxylene adipamide (N-MXD6) film, etc. The gas barrier film has a drawback that its gas barrier property is lowered under high humidity conditions. However, when the adhesive film of the present invention is used to produce a laminate film containing these gas barrier films, this disadvantage is solved. be able to.

  Furthermore, since the cured epoxy resin in the present invention is excellent in toughness and heat-and-moisture resistance, a gas barrier laminate film excellent in impact resistance, boiling resistance, retort resistance and the like can be obtained.

  In the case of laminating various film materials using the adhesive in the present invention, a known laminating method such as dry lamination, non-solvent laminating, extrusion laminating, etc. can be used. Is preferred.

  When the adhesive in the present invention is applied to various materials and laminated, it is carried out at a concentration and temperature of an epoxy resin composition sufficient to obtain an epoxy resin cured product that becomes an adhesive layer. It can vary depending on the choice of materials and lamination methods. That is, the concentration of the epoxy resin composition is about 5% by weight using a certain kind of appropriate organic solvent and / or water from the case where no solvent is used depending on the type and molar ratio of the selected material, the laminating method, and the like. Various states can be taken up to the case where the coating liquid is prepared by diluting to the composition concentration. As the organic solvent to be used, any solvent having solubility with an adhesive can be used. For example, water-insoluble solvents such as toluene, xylene, methyl acetate, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1-methoxy-2 Glycol ethers such as 1-propanol, 1-ethoxy-2-propanol, 1-propoxy-2-propanol, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, N, Examples include aprotic polar solvents such as N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone.

  The adhesive (coating solution) diluted with a solvent can be diluted at a concentration such that the Zahn cup (No. 3) viscosity is in the range of 5 to 30 seconds (25 ° C.). If the Zahn cup (No. 3) viscosity is less than 5 seconds, the adhesive is not sufficiently applied to the object to be coated, which may cause roll contamination. On the other hand, when the Zahn cup (No. 3) viscosity exceeds 30 seconds, the adhesive is not sufficiently transferred to the roll, and it becomes difficult to form a uniform adhesive layer. For example, in dry lamination, the Zahn cup (No. 3) viscosity is preferably 10 to 20 seconds (25 ° C.) during use.

  In order to suppress foaming of the coating liquid when preparing the coating liquid in the present invention, an antifoaming agent such as silicon or an acrylic compound may be added to the coating liquid. Suitable antifoaming agents include BYK019, BYK052, BYK067N, BYK070, BYK080, and the like available from Big Chemie, with BYK019 being particularly preferred. Moreover, when adding these antifoamers, the range of 0.01 weight%-3.0 weight% is preferable on the basis of the total weight of the epoxy resin composition in a coating liquid, 0.02 weight%-2 More preferred is 0.0% by weight.

  When a solvent is used, the solvent drying temperature after application of the adhesive may vary from 20 ° C. to 140 ° C., but it is close to the boiling point of the solvent and affects the object to be coated. No temperature is desirable. When the drying temperature is less than 20 ° C., the solvent remains in the laminate film, which causes poor adhesion and odor. When the drying temperature exceeds 140 ° C., it becomes difficult to obtain a laminate film having a good appearance due to softening of the polymer film. For example, when apply | coating an adhesive agent to a stretched polypropylene film, 40 to 120 degreeC is desirable.

  Any of commonly used coating formats such as roll coating, spray coating, air knife coating, dipping, and brush coating can be used as the coating format for applying the adhesive. Roll coating or spray coating is preferred. For example, the same roll coat or spray technique and equipment as when a polyurethane adhesive component is applied to a polymer film and laminated can be applied.

Next, specific operations in each laminating method will be described. In the case of the dry laminating method, the coating liquid is applied to a film material containing a base material (in which an ink layer, a resin (A) layer, or another layer is laminated on the base material) with a roll such as a gravure roll. Thereafter, the solvent is dried and a new film material is immediately bonded to the surface with a nip roll to obtain a laminate film. The solvent for preparing the adhesive is preferably a solvent having good solubility and a relatively low boiling point and containing an alcohol having 3 or less carbon atoms. The group consisting of methanol, ethanol, isopropanol, and n-propanol The solvent which has as a main component 1 or more types chosen from is illustrated. In addition, it is a mixed solution in which a solvent having an ester group, ketone group, or aldehyde group functional group that has the effect of delaying the reaction between the epoxy resin and the polyamine and suppressing the increase in the viscosity of the adhesive to prolong the working time. Preferably there is. As a mixed solution in which a solvent having any functional group of an ester group, a ketone group, or an aldehyde group is mixed, it is selected from the group consisting of methyl acetate, ethyl acetate, acetone, methyl ethyl ketone, acetaldehyde, and propionaldehyde having a relatively low boiling point. The liquid mixture which mixed 1 or more types is illustrated. In order to obtain a film with a small amount of solvent remaining in the obtained laminate film, the content of the solvent having any functional group of ester group, ketone group, and aldehyde group is preferably 20% by weight or less in the total solvent. Here, if there is a large amount of solvent remaining in the laminate film, it may cause a bad odor. Therefore, the amount of the remaining solvent is practically 7 mg / m ² or less, and if it is more than 7 mg / m ² , a strange odor is felt from the film. Cause. Preferably 5 mg / ^{m 2} or less in the case of strictly control the odor of the film, 3 mg / ^{m 2} or less is particularly preferred.

  In the dry laminating method, the adhesive can also be applied to the sealant layer, applied to a polyolefin film such as a polyethylene film, a polypropylene film, or an ethylene-vinyl acetate copolymer, dried, and then stretched polypropylene or a polyamide film. By laminating a base material such as a polyethylene terephthalate film, a laminate film can be produced.

  In the case of bonding by nip roll, the nip roll can be heated and bonded to 20 ° C. to 120 ° C., but 40 to 100 ° C. is desirable.

  In this case, it is desirable to complete the curing reaction by performing aging at 20 ° C. to 60 ° C. for a certain time as necessary after lamination. By performing aging for a certain period of time, a cured epoxy resin is formed with a sufficient reaction rate, and high gas barrier properties are exhibited. When the aging is 20 ° C. or less or without aging, the reaction rate of the epoxy resin composition is low, and sufficient gas barrier properties and adhesive strength cannot be obtained. Also, aging at 60 ° C. or higher can cause problems such as polymer film blocking and additive elution.

  In the case of the non-solvent laminating method, a roll such as a gravure roll in which the adhesive in the present invention, which has been heated to about 40 ° C. to 100 ° C. in advance on a film material containing a substrate, is heated to 40 ° C. to 120 ° C. After the coating, a laminate film can be obtained by pasting a new film material on the surface immediately after coating. In this case as well, as in the case of the dry laminating method, it is desirable to perform aging for a predetermined time after the lamination as necessary.

In the case of the extrusion laminating method, the epoxy resin and the epoxy resin curing agent, which are the main components of the adhesive in the present invention, are diluted with an organic solvent and / or water as an adhesive aid (anchor coating agent) for the film material including the base material. The solution is applied by a roll such as a gravure roll, and after drying and curing the solvent at 20 ° C. to 140 ° C., a laminate film can be obtained by laminating the polymer material melted by an extruder. The polymer material to be melted is preferably a polyolefin resin such as a low density polyethylene resin, a linear low density polyethylene resin, or an ethylene-vinyl acetate copolymer resin.
These laminating methods and other laminating methods that can be generally used can be combined as necessary, and the layer structure of the laminating film can be changed depending on the application and form.

  The thickness of the adhesive layer after applying, drying, bonding and heat-treating the adhesive in the present invention to various materials is 0.1 to 100 μm, preferably 0.5 to 10 μm. If the thickness is less than 0.1 μm, sufficient gas barrier properties and adhesiveness are hardly exhibited. On the other hand, if the thickness exceeds 100 μm, it is difficult to form an adhesive layer having a uniform thickness.

  The laminate film of the present invention has excellent laminate strength. The laminate strength at a peeling speed of 300 mm / min after the heat treatment varies depending on the material of the base material and the sealant layer. For example, when the base material is stretched polypropylene, 80 g / 15 mm or more is preferable, and 100 g / 15 mm or more is more preferable. It is preferably 120 g / 15 mm or more. On the other hand, when the base material is stretched nylon or polyethylene terephthalate, if the sealant layer is low density polyethylene, it is preferably 600 g / 15 mm or more, more preferably 700 g / 15 mm or more, and particularly preferably 800 g / 15 mm or more. If is unstretched polypropylene, it is preferably 300 g / 15 mm or more, more preferably 400 g / 15 mm or more, and particularly preferably 500 g / 15 mm or more.

  The laminate film produced using the adhesive in the present invention can be used as a multilayer packaging material for the purpose of protecting foods and pharmaceuticals. When used as a multi-layer packaging material, the layer structure can be changed according to the contents, use environment, and use form. That is, the laminate film in the present invention can be used as a multilayer packaging material as it is, and if necessary, an oxygen absorbing layer, a thermoplastic resin film layer, a paper layer, a metal foil layer and the like are further laminated on the laminate film in the present invention. It can also be made. Under the present circumstances, you may laminate using the adhesive agent in this invention, and you may laminate using another adhesive agent and an anchor coat agent.

  A packaging bag made of a soft packaging bag manufactured using the multilayer packaging material will be described. A packaging bag made of such a soft packaging bag uses the multilayer packaging material, and the surfaces of the heat-sealable resin layer are overlapped to face each other, and then the peripheral end is heat-sealed to form a seal part. Can be produced. As the bag making method, for example, the multilayer packaging material is folded or overlapped so that the inner layer faces each other, and the peripheral edge thereof is, for example, a side seal type, a two-side seal type, or a three-side seal type. , Four-side seal type, envelope sticker seal type, jointed sticker seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset type, etc. It is done. The packaging bag can take various forms depending on the contents, use environment, and use form. In addition, for example, a self-supporting packaging bag (standing pouch) is also possible. As a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, or an ultrasonic seal can be used.

  A packaging product using the packaging bag of the present invention can be manufactured by filling the packaging bag with the contents from the opening and then heat-sealing the opening. The contents that can be filled include rice confectionery, bean confectionery, nuts, biscuits and cookies, wafer confectionery, marshmallows, pies, semi-baked cakes, candy, snack confectionery and other confectionery, bread, snack noodles, instant noodles, dried noodles, pasta, Aseptic packaging cooked rice, elephant, rice cracker, packaging rice cake, cereals and other staples, pickles, boiled beans, natto, miso, frozen tofu, tofu, licked rice, konjac, wild vegetable products, jams, peanut cream, salads, frozen vegetables Agricultural processed products such as processed potatoes, hams, bacon, sausages, processed chicken products, livestock processed products such as corned beef, fish hams and sausages, marine products, kamaboko, paste, boiled bonito, salted, smoked Seafood products such as salmon, mentaiko, peaches, tangerines, pineapples, apples, pears, Cooking of fruit such as cherries, vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, potatoes, hamburger, meatballs, marine fries, gyoza, croquettes, etc. Examples include dairy products such as finished food, butter, margarine, cheese, cream, instant creamy powder, and infant formula, liquid seasonings, retort curry, and pet food. It can also be used as a packaging material for tobacco, disposable body warmers, pharmaceuticals, cosmetics and the like.

  Examples of the present invention are introduced below, but the present invention is not limited to these examples.

<Epoxy resin curing agent a>
A reaction vessel was charged with 1 mole of metaxylylenediamine. The temperature was raised to 60 ° C. under a nitrogen stream, and 0.93 mol of methyl acrylate was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was stirred at 120 ° C. for 1 hour, and further heated to 160 ° C. in 3 hours while distilling off generated methanol. The mixture was cooled to 100 ° C., and a predetermined amount of methanol was added so that the solid content concentration became 70% by weight to obtain an epoxy resin curing agent a. The content of amide groups in the epoxy resin curing agent a was 21% by weight.

In addition, evaluation methods such as oxygen permeability and laminate strength are as follows.
<Oxygen permeability (ml / m ² · day · MPa)>
The oxygen permeability of the laminate film was measured under the conditions of 23 ° C. and 60% relative humidity using an oxygen permeability measuring device (Modern Control, OX-TRAN10 / 50A).
<Lamination strength (g / 15mm)>
Using the method specified in JISK-6854, the laminate strength of the laminate film was measured by a T-type peel test at a peel rate of 300 mm / min.
<Heat seal strength (kg / 15mm)>
The sealant layers of the two laminate films are heat sealed at 2kg / cm ² for 1 second at 150 ° C using a thermal gradient heat seal machine (Type HG-100) manufactured by Toyo Seiki Seisakusho Co., Ltd. The strength of the heat seal part was measured by the same method.

<Example 1>
Methanol / ethyl acetate containing 9 parts by weight of epoxy resin having a glycidylamine moiety derived from metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd .; TETRAD-X) and 146 parts by weight of epoxy resin curing agent a = 9 / 1 solution (solid content concentration: 35% by weight) was prepared, and 0.4 parts by weight of an acrylic wetting agent (BIC Chemie; BYK381) and a silicon-based antifoaming agent (BIC Chemie; BYK019) were prepared. ) Was added and stirred well to obtain an adhesive having a Zahn cup (No. 3) viscosity of 14 seconds (25 ° C.).
A stretched 6-nylon film (Harden N1102 manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm was used as a base material, and a hardener (polyurethane resin-based white gravure ink (NT-HIRAMIC 701R white; manufactured by Dainichi Seika Kogyo Co., Ltd.)) NT-Hilamic Hardener; manufactured by Dainichi Seika Kogyo Co., Ltd.) is added to the ink in an amount of 5%, and a mixed solvent of ethyl acetate / MEK / IPA = 4/4/2 is added to the Zahn cup (No. 3) viscosity. After adjusting to 16 seconds (25 ° C.) and applying to a substrate using a 38 μm plate depth roll, a polyurethane resin-based medium (corresponding to resin (A), NT-Hilamic-R medium; Dainichi Seika Kogyo ( Co., Ltd.) was added to a mixed solvent of ethyl acetate / MEK / IPA = 4/4/2 to adjust the Zahn cup (No. 3) viscosity to 16 seconds (25 ° C.) and use a plate depth 38 μm roll to obtain ink. Application surface After that, the adhesive was applied using a gravure roll having a 100 line / inch depth of 100 μm, and then dried in a drying oven at 60 ° C. (near the entrance) to 90 ° C. (near the exit). A linear polyethylene film (TUX MC-S manufactured by Tosero Co., Ltd.) was bonded together by a nip roll heated to 70 ° C., wound at a winding speed of 130 m / min, and the roll was aged at 40 ° C. for 4 days. As a result, a laminate film composed of a substrate / ink layer / resin (A) layer / adhesive layer / sealant layer was obtained. The resulting laminated film was evaluated for its gas barrier properties, laminate strength, and heat seal strength. The results are shown in Table 1. The content of the skeleton structure of the formula (1) in the adhesive layer (cured epoxy resin) was 62.0% by weight. The adhesive layer thickness was 3.8 μm, and the oxygen permeability coefficient calculated from the oxygen permeability was 0.3 ml · mm / m ² · day · MPa (23 ° C., 60% RH).

<Example 2>
A laminate film was produced in the same manner as in Example 1, except that a stretched polyethylene terephthalate film (Toyobo Co., Ltd. Ester film E5100) having a thickness of 12 μm was used instead of the stretched 6-nylon film having a thickness of 15 μm. The results are shown in Table 1.

<Example 3>
A laminate film was produced in the same manner as in Example 1 except that a stretched polypropylene film having a thickness of 20 μm (Pyrene P2161 manufactured by Toyobo Co., Ltd.) was used instead of the stretched 6-nylon film having a thickness of 15 μm. The results are shown in Table 1.

<Example 4>
Example 1 except that a polyurethane resin / vinyl chloride-vinyl acetate copolymer resin-based white gravure ink (NB300 SC white; manufactured by Dainichi Seika Kogyo Co., Ltd.) was used instead of the polyurethane resin-based white gravure ink. A laminate film was prepared by the method described above. The results are shown in Table 1.

<Example 5>
Instead of polyurethane resin-based white gravure ink, chlorinated polypropylene resin-based white gravure ink (UNITAF 793 white; manufactured by Dainippon Ink & Chemicals, Inc.) is used. A laminate film was produced in the same manner as in Example 1 except that a stretched polypropylene film having a thickness of 20 μm (Pyrene P2161 manufactured by Toyobo Co., Ltd.) was used instead of the 6-nylon film. The results are shown in Table 1.

<Comparative Example 1>
A laminate film was produced in the same manner as in Example 1 except that the medium was not applied. The results are shown in Table 1.

<Comparative example 2>
A laminate film was produced in the same manner as in Example 2 except that the medium was not applied. The results are shown in Table 1.

<Comparative Example 3>
A laminate film was produced in the same manner as in Example 3 except that the medium was not applied. The results are shown in Table 1.

<Comparative example 4>
A laminate film was produced in the same manner as in Example 4 except that the medium was not applied. The results are shown in Table 1.

Claims (4)

A layer comprising at least one resin (A) selected from at least a substrate, an ink layer, a polyurethane resin, a vinyl chloride-vinyl acetate copolymer resin, a rosin resin, a polyamide resin, and a chlorinated olefin resin; A laminate film in which an adhesive layer and a sealant layer are laminated in this order, and the adhesive forming the adhesive layer is mainly composed of an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent. A laminate film comprising 40% by weight or more of a skeleton structure represented by the formula (1) in a cured epoxy resin obtained by curing the epoxy resin composition.

The laminate film according to claim 1, wherein the cured epoxy resin has an oxygen barrier property of an oxygen permeability coefficient of 1.0 ml · mm / m ² · day · MPa (23 ° C., 60% RH) or less.   The laminate film according to claim 1, wherein the laminate film is produced by a dry lamination method. A packaging bag comprising the laminate film according to claim 1 and heat-sealed.