JP5966511B2 - Laminate film - Google Patents

Description

  The present invention relates to a laminate film and a method for producing the same. In detail, it is related with the laminate film used suitably for packaging materials, such as a foodstuff and a pharmaceutical.

  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. A dry laminating method in which a sealant layer is adhered by applying an adhesive, or an extrusion laminating method in which a molten plastic film to be a sealant layer is pressure-bonded and laminated to a laminate film after applying an anchor coating agent to the laminate film as necessary. ing.

  As the adhesive used in the laminating method, a two-component polyurethane adhesive composed of a main agent having an active hydrogen-containing group such as a hydroxyl group and a curing agent having an isocyanate group is generally used because of its high adhesive performance. (See Patent Documents 1 and 2).

However, since these two-component polyurethane adhesives generally do not have a very fast curing reaction, they are cured by aging over a long period of 1 to 5 days after bonding to ensure sufficient adhesion. There was a need to promote. In addition, since a curing agent having an isocyanate group is used, if an unreacted isocyanate group remains after curing, the residual isocyanate group reacts with moisture in the atmosphere to generate carbon dioxide, and bubbles are formed in the laminate film. There was a problem such as.
As methods 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 the above-mentioned polyurethane-based adhesive and epoxy-based laminating adhesive are not high, and for packaging material applications that require gas barrier properties, polyvinylidene chloride (PVDC) coating layers, polyvinyl alcohol (PVA) coating layers, Various gas barrier layers such as an ethylene-vinyl alcohol copolymer (EVOH) film layer, a metaxylylene adipamide film layer, a film layer deposited with alumina or silica, and a sealant layer such as a flexible polymer film layer. Therefore, it is necessary to bond through an adhesive layer such as an adhesive layer or an anchor coat layer, which increases the manufacturing cost of the laminate film and complicates the laminating process (see Patent Document 5).
As a method for solving these problems, an adhesive for gas barrier laminates has been proposed (see Patent Document 6).

However, the above gas barrier laminate adhesive may cause peeling of the adhesive layer on the ink layer and a decrease in the cohesive strength of the ink when printing is performed on the substrate on which the adhesive is applied. There was a problem that the laminate strength of the laminate film was lowered. Further, since the gas barrier laminating adhesive uses alcohol as a diluting solvent, when a polyamide film is used as a base material, a large amount of alcohol remains in the laminate film due to penetration of the alcohol into the polyamide film. There was a problem.
As a method for solving these problems, a method of coating a primer on an ink layer has been proposed (see Patent Document 7).

  However, the laminate film prepared by coating the above primer has improved the initial laminate strength, but the results over time are not shown, and depending on the storage conditions, the laminate strength and heat seal strength are said to decrease. There was a problem.

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 JP 2007-038630 A

  An object of the present invention is to solve the above-mentioned problems and to provide a laminate film excellent in adhesiveness with time, which can maintain excellent laminate strength and heat seal strength even when stored for a long period of time.

  As a result of intensive studies to solve the above problems, the present inventors have found that at least a primer containing a specific polyester-based resin in a laminate film in which a base material, a primer layer, an adhesive layer, and a sealant layer are laminated in this order. By forming a primer layer using the composition and forming an adhesive layer using an adhesive mainly composed of an epoxy resin composition, excellent laminate strength and heat seal strength even after long-term storage It was found that a laminate film excellent in adhesiveness with time can be obtained, and the present invention has been achieved.

The present invention relates to the following [1] to [8].
[1] A laminate film in which at least a substrate, a primer layer, an adhesive layer, and a sealant layer are laminated in this order, and the primer composition forming the primer layer has an acid value of 10 to 100 KOHmg / g And the adhesive which contains the polyester-type resin (a) whose glass transition temperature is -20-120 degreeC, and forms this adhesive bond layer has as a main component the epoxy resin composition which consists of an epoxy resin and an epoxy resin hardening | curing agent. A laminate film characterized by being a thing.
[2] The laminate film according to [1], wherein the content of the polyester resin (a) in the primer composition is 5 to 100% by mass.
[3] The primer composition according to [1] or [2], wherein the primer composition further comprises a polyester resin (b) having an acid value of less than 10 KOHmg / g and a glass transition temperature of -20 to 120 ° C. Laminate film.
[4] The mixing ratio [(a) / (b)] of the polyester resin (a) and the polyester resin (b) contained in the primer composition exceeds 0.1 by mass ratio. The laminate film according to [3] above.
[5] Any of the above [1] to [4], wherein the cured epoxy resin obtained by curing the epoxy resin composition contains 40% by mass or more of the skeleton structure represented by the following general formula (1) The laminate film described in 1.

[6] The laminate film according to any one of [1] to [5], wherein the substrate is a substrate containing at least polyamide.
[7] Any of the above [1] to [6], wherein the adhesive layer has an oxygen barrier property with an oxygen permeability coefficient at 23 ° C. and 60% RH of 1.0 ml · mm / m ² · day · MPa or less. The laminated film of crab.
[8] The laminate film according to any one of [1] to [7], which is produced by a dry lamination method.

The laminate film of the present invention has excellent adhesiveness over time, and can maintain excellent laminate strength and heat seal strength even when stored for a long period of time.
Further, even when a base material containing polyamide is used as the base material constituting the laminate film, the drying property of the solvent is good, which is advantageous in terms of workability in the manufacturing process. Further, the laminate film has an excellent laminate strength even when the substrate is printed.

[Laminate film]
The laminate film of the present invention is obtained by laminating at least a substrate, a primer layer, an adhesive layer, and a sealant layer in this order. When making a laminate film, the base material is used on the outer surface of the bag and the sealant layer is used on the inner surface of the bag. In the laminate film of the present invention, an ink layer formed by printing or the like may be interposed between the substrate and the primer layer.

  Furthermore, a film material such as polyolefin or polyester may be laminated between the adhesive layer and the sealant layer as a layer other than the base material, the primer layer, the adhesive layer, and the sealant layer. When laminating various materials, a plurality of adhesive layers may be provided. Moreover, you may use together adhesive agents other than the adhesive agent used for this invention.

(Base material)
As a base material used for the laminate film of the present invention, for example, polyamide film such as nylon 6, nylon 6,6, polymetaxylylene adipamide (N-MXD6); low density polyethylene, high density polyethylene, linear Polyolefin films such as low density polyethylene and polypropylene; Polyester films such as polyethylene terephthalate and polybutylene terephthalate; Polyacrylonitrile films; Poly (meth) acrylate films; Polystyrene films; Polycarbonate films; Ethylene-vinyl alcohol copolymer Combined (EVOH) -based film: Plastic film such as polyvinyl alcohol film, paper such as carton, metal foil such as aluminum and copper, and the like. The substrate may be a single layer or a multilayer, and may be a substrate obtained by laminating two or more kinds of materials.
Among the above, from the viewpoint of gas barrier properties, the substrate is preferably a substrate containing polyamide. Examples of the base material containing polyamide include polyamide films such as nylon 6, nylon 6,6, polymetaxylylene adipamide (N-MXD6), and thermoplastic resins such as polyolefin and polyester on the polyamide film. Examples thereof include a mixed film and a film obtained by laminating a material other than the polyamide film on the polyamide film.
The thickness of the substrate is practically about 10 to 300 μm, preferably about 10 to 100 μm. In the case of a plastic film, it may be stretched in a uniaxial or biaxial direction.

  The surface of the base material is preferably subjected to various surface treatments such as flame treatment and corona discharge treatment as necessary. By this surface treatment, a primer layer free from defects such as film breakage and repellency is formed on the substrate, and the adhesion of the primer layer to the substrate is improved.

(Ink layer)
An ink layer can be provided on the surface of the substrate as necessary. Ink layers are organic pigments such as azo, phthalocyanine, and isoindolinone; inorganic pigments such as titanium dioxide, carbon black, and calcium carbonate; polyurethane resins, polyester resins, polyurethane urea resins, acrylic modified urethane resins, acrylic modified Polyurethane resins such as urethane urea resins; Vinyl chloride-vinyl acetate copolymer resins; Rosin resins such as rosin-modified maleic acid resins; Polyamide resins; Chlorinated olefin resins such as chlorinated polypropylene resins; Acrylic resins; Binder resins such as nitrocellulose-based resins and rubber-based resins; inks that have been used for printing layers on conventional polymer films formed from solvents such as water, methanol, 2-propanol, ethyl acetate, methyl ethyl ketone, and toluene Formed by For the formation of the ink layer, general printing equipment that has been used for printing on a conventional polymer film such as a gravure printing machine, a flexographic printing machine, and an offset printing machine can be similarly applied.

The ink for forming the ink layer may be a one-component curing type or a two-component curing type, but in the case of the two-component curing type, it is preferable 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.
The thickness of the ink layer is preferably about 0.01 to 10 μm, more preferably about 0.1 to 5 μm.

(Primer layer)
The primer layer in the laminate film of the present invention is formed by a primer composition having adhesiveness with the substrate and / or the ink layer.
In the present invention, the primer composition comprises a polyester resin (a) having an acid value of 10 to 100 KOHmg / g and a glass transition temperature (hereinafter sometimes referred to as “Tg”) of −20 to 120 ° C. Contains as an essential component.

<Polyester resin (a)>
The polyester resin (a) is a polyester resin having an acid value of 10 to 100 KOHmg / g and a Tg of -20 to 120 ° C.
If the acid value is less than 10 KOHmg / g, the adhesion of the primer layer to the substrate, especially the adhesive over time when the laminate film is stored for a long period of time, decreases. If the acid value exceeds 100 KOHmg / g, the polyester Since the cohesive force of the resin itself becomes small, it becomes brittle and cohesive failure easily occurs, so that the laminate strength in the case of a laminate film is lowered.
Moreover, since the solubility to an organic solvent will become low when Tg of the said polyester-type resin (a) becomes higher than 120 degreeC, it becomes difficult to apply | coat a primer composition to a base material, on the other hand, lower than -20 degreeC. In this case, when the primer layer is applied to the substrate and wound up once, blocking between the substrates may become a problem.
Specific examples of the polyester resin (a) include “Byron UR-1700” and “Byron UR-3500” (both trade names) manufactured by Toyobo Co., Ltd. These polyester resins (a) can be used alone or in combination of two or more.

  The content of the polyester-based resin (a) in the primer composition is preferably 5 to 100% by mass, more preferably 10 to 100% by mass, and still more preferably, from the viewpoint of improving the adhesiveness with time of the laminate film. It is 20-100 mass%, More preferably, it is 25-100 mass%.

<Polyester resin (b)>
Moreover, it is preferable that the said primer composition further contains the polyester-type resin (b) whose acid value is less than 10 KOHmg / g and Tg is -20-120 degreeC. In the primer composition, by mixing and using two or more kinds of polyester resins having different acid values, the adhesion to the substrate and the solvent drying property of the resulting laminate film are improved.
As the polyester-based resin (b), polyester-based resins having various chemical structures can be used for both the one-component curable type and the two-component curable type.
Specifically, for example, “AD-76H5” / “CAT-10L” (trade name) manufactured by Toyo Ink Co., Ltd., which is a two-component curable polyester resin, Toyobo Co., Ltd., which is a one-component polyester resin. ) “Byron 200”, “Byron 600”, “Byron 630”, “Byron GK640” (all trade names) and the like.
The polyester resin (b) only needs to have a polyester skeleton as a main component, and a polyester resin modified with urethane or the like in advance can also be used. Specific examples of the modified polyester resin include “Byron UR-1350”, “Byron UR-1400”, “Byron UR-2300” (all trade names) manufactured by Toyobo Co., Ltd., and the like. .
These polyester resins (b) can be used alone or in combination of two or more.
The one-component polyester resin may be used in combination with a curing agent such as isocyanate, epoxy, melamine, or phenol resin. Specific examples of the curing agent include “Coronate L” and “Coronate 2037” (both trade names) which are isocyanate curing agents manufactured by Nippon Polyurethane Industry Co., Ltd. More than one type can be used in combination.

  When the primer composition contains the polyester resin (b), the mixing ratio of the polyester resin (a) and the polyester resin (b) contained in the primer composition [(a) / ( b)] is preferably more than 0.1 by mass ratio, more preferably 0.2 or more, and still more preferably 0.25 or more. When the mixing ratio exceeds 0.1, the adhesiveness with time is improved, and the solvent drying property is improved even when the base material containing the polyamide described above is used as the base material.

  The primer composition may contain an additive in order to impart other functions to the primer layer of the laminate film of the present invention. As the additive, for example, a wax, a dispersant, an antistatic agent, a surface modifier and the like are appropriately selected for improving friction resistance, preventing blocking, slipping, improving heat resistance, preventing antistatic, and the like. Can be used.

  A practical thickness of the primer layer is 0.01 to 20 μm, preferably 0.1 to 5 μm. If the thickness of the primer layer is 0.01 μm or more, sufficient adhesion can be obtained, while if it is 20 μm or less, a primer layer having a uniform thickness can be formed.

(Adhesive layer)
The adhesive layer in the laminate film of the present invention is formed of an adhesive mainly composed of an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent.

<Adhesive>
The adhesive used in the present invention is mainly composed of an epoxy resin composition comprising an epoxy resin and an epoxy resin curing agent.
From the viewpoint of gas barrier properties, the cured epoxy resin obtained by curing the epoxy resin composition in the adhesive layer of the laminate film of the present invention has a skeletal structure represented by the following general formula (1) of 40% by mass. It is preferable to contain above. The content is preferably 45% by mass or more, more preferably 50% by mass or more.

When the skeleton structure of the general formula (1) is contained in the cured epoxy resin in an amount of 40% by mass or more, a high gas barrier property is exhibited, and the oxygen permeability coefficient at 23 ° C. and 60% RH is 1.0 ml · mm. An adhesive layer having an oxygen barrier property of not more than / m ² · day · MPa can also be obtained. Below, the epoxy resin and epoxy resin hardening | curing agent which are contained in the epoxy resin composition which is a main component of an epoxy resin composition are demonstrated.

〔Epoxy resin〕
The epoxy resin used as a component of the adhesive in the present invention may be any of an aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound, but when considering the expression of high gas barrier properties. Is preferably an epoxy resin containing an aromatic moiety in the molecule, and more preferably an epoxy resin containing the skeleton structure of the general formula (1) in the molecule.
Specific examples of the epoxy resin include an epoxy resin having a glycidylamino group derived from metaxylylenediamine, an epoxy resin having a glycidylamino group derived from 1,3-bis (aminomethyl) cyclohexane, and diaminodiphenylmethane. Epoxy resin having glycidylamino group derived, epoxy resin having glycidylamino group and / or glycidyloxy group derived from paraaminophenol, epoxy resin having glycidyloxy group derived from bisphenol A, bisphenol F Epoxy resin having glycidyloxy group, epoxy resin having glycidyloxy group derived from phenol novolac, and epoxy resin having glycidyloxy group derived from resorcinol Etc., and the like. Among them, an epoxy resin having a glycidylamino group derived from metaxylylenediamine, an epoxy resin having a glycidylamino group derived from 1,3-bis (aminomethyl) cyclohexane, and a glycidyloxy group derived from bisphenol F Epoxy resins and epoxy resins having a glycidyloxy group derived from resorcinol are preferred.
Furthermore, it is more preferable to use an epoxy resin having a glycidyloxy group derived from bisphenol F or an epoxy resin having a glycidylamino group derived from metaxylylenediamine as a main component. More preferably, an epoxy resin having a glycidylamino group is used 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 can be obtained by reaction of alcohols, phenols and amines with epihalohydrin. For example, an epoxy resin having a glycidylamino group derived from metaxylylenediamine can be obtained by adding epichlorohydrin to metaxylylenediamine. Because metaxylylenediamine has four amino hydrogens, mono-, di-, tri-, and tetraglycidyl compounds are formed. The number of glycidyl groups can be changed by changing the reaction ratio between metaxylylenediamine and epichlorohydrin. For example, an epoxy resin having mainly four glycidyl groups 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 alkali such as sodium hydroxide at 20 to 140 ° C., preferably 50 to 120 ° C. for alcohols and phenols, amine In the case of the class, it is synthesized by reacting at a temperature of 20 to 70 ° C. and separating the by-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.

[Epoxy resin curing agent]
In the present invention, the epoxy resin curing agent used as a component of the adhesive may be any of an aliphatic compound, an alicyclic compound, an aromatic compound, or a heterocyclic compound, such as polyamines, phenols, and acid anhydrides. Or generally used epoxy resin curing agents such as carboxylic acids 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, examples of 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 thereof include alicyclic amines such as bis (aminomethyl) cyclohexane, isophoronediamine and norbornanediamine; and aromatic amines such as diaminodiphenylmethane and metaphenylenediamine. In addition, epoxy resins using these as raw materials, modification reaction products of polyamines and monoglycidyl compounds, modification reaction products of polyamines and epichlorohydrin, modification reactions of polyamines and alkylene oxides having 2 to 4 carbon atoms. Products, amide oligomers obtained by reaction of polyamines with polyfunctional compounds having at least one acyl group, polyamines, polyfunctional compounds having at least one acyl group, and monovalent carboxylic acids and / or Amide oligomers obtained by reaction with the derivatives can also be used as epoxy resin curing agents.

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

In consideration of expression of high gas barrier properties, an epoxy resin curing agent containing an aromatic moiety in the molecule is preferable, and an epoxy resin curing agent including the skeleton structure of the general formula (1) in the molecule is more preferable.
Specifically, as the epoxy resin curing agent, metaxylylenediamine or paraxylylenediamine, a reaction product with an epoxy resin or a monoglycidyl compound using these as raw materials, and an alkylene oxide having 2 to 4 carbon atoms Reaction product, reaction product with epichlorohydrin, reaction product with polyfunctional compound having at least one acyl group capable of forming an amide group site by reaction with these polyamines to form an oligomer A reaction product of a polyfunctional compound having at least one acyl group and a monovalent carboxylic acid and / or its derivative, which can form an amide group site by reaction with these polyamines to form an oligomer, etc. More preferably, is used.

In consideration of high gas barrier properties and high adhesion to the substrate or ink layer, sealant layer, and other layers, as the epoxy resin curing agent, the following reaction products (A) and (B), or More preferably, the reaction products (A), (B) and (C) are used.
(A) a polyfunctional compound having at least one acyl group that can form an amide group site by reaction with metaxylylenediamine or paraxylylenediamine (B) polyamine to form an oligomer (C) having 1 to 1 carbon atoms 8 monovalent carboxylic acids and / or derivatives thereof

The polyfunctional compound (B) having at least one acyl group capable of forming an amide group site by reaction with the polyamine to form an oligomer is a compound having two or more reactive functional groups, A compound having at least one functional group capable of forming an amide group site by reaction with a polyamine and having at least one acyl group. Examples of the “reactive functional group” herein include functional groups capable of forming an amide group site by reaction with the polyamine, and ethylenically unsaturated bonds. Further, “at least one acyl group” of the polyfunctional compound (B) may be included in the reactive functional group.
Examples of such component (B) include carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, succinic acid, malic acid, tartaric acid, adipic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and trimellitic acid. And derivatives thereof such as esters, amides, acid anhydrides, acid chlorides and the like, and acrylic acid, methacrylic acid and derivatives thereof are particularly preferable.

Examples of the monovalent carboxylic acid (C) having 1 to 8 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, glycolic acid, benzoic acid and the like, and derivatives thereof such as esters, amides, Acid anhydrides, acid chlorides and the like can also be used. These may be used in combination with the polyfunctional compound (B) and reacted with metaxylylenediamine or paraxylylenediamine (A).
The amide group site introduced by the above reaction has a high cohesive force, and the presence of the amide group site in a high proportion in the epoxy resin curing agent results in higher gas barrier properties and a substrate or printed layer, sealant. Good adhesion to layers and other layers is obtained.

The reaction molar ratio of (A) and (B) in the reaction products of (A) and (B) is the reactive functional group contained in (B) with respect to the number of amino groups contained in (A). The ratio of the number of [number of reactive functional groups contained in (B) / number of amino groups contained in (A)] is preferably in the range of 0.30 to 0.97.
Similarly, the reaction molar ratio of (A), (B) and (C) in the reaction products of (A), (B) and (C) is based on the number of amino groups contained in (A). Ratio of the total number of reactive functional groups contained in (B) and (C) [number of reactive functional groups contained in (B) and (C) / number of amino groups contained in (A) ] Is preferably in the range of 0.30 to 0.97.
When the reaction molar ratio is 0.30 or more, a sufficient amount of amide groups are generated in the epoxy resin curing agent, and high levels of gas barrier properties and adhesiveness are exhibited. Further, the proportion of volatile molecules remaining in the epoxy resin curing agent is reduced, and no odor is generated from the obtained cured product. Moreover, since the ratio of the hydroxyl group in the cured reaction product generated by the reaction between the epoxy group and the amino group is lowered, the gas barrier property in a high humidity environment is improved.
On the other hand, if the reaction molar ratio is 0.97 or less, the amount of amino groups that react with the epoxy resin increases, and excellent impact resistance, heat resistance, etc. are exhibited, and the solubility in various organic solvents or water is high. improves.

  When particularly considering the high gas barrier property, adhesiveness, suppression of odor generation and high gas barrier property in a high humidity environment of the resulting cured epoxy resin, the reaction product of the above (A) and (B) [ Number of reactive functional groups contained in (B) / number of amino groups contained in (A)] and [(B) in the reaction products of (A), (B) and (C) above And the number of reactive functional groups contained in (C) / the number of amino groups contained in (A)] is more preferably in the range of 0.60 to 0.97, and 0.80 to 0 Is more preferably in the range of .97, and particularly preferably in the range of 0.85 to 0.97. In consideration of higher adhesiveness, the epoxy resin curing agent preferably contains 6% by mass or more of an amide group based on the total mass of the curing agent.

  A more preferable epoxy resin curing agent is a reaction between metaxylylenediamine (the component (A)) and at least one compound selected from acrylic acid, methacrylic acid and / or a derivative thereof (the component (B)). The ratio of the number of reactive functional groups contained in at least one compound selected from acrylic acid, methacrylic acid and / or derivatives thereof to the amino group contained in the metaxylylenediamine is 0. The range is from 80 to 0.97.

[Epoxy resin composition]
The adhesive used for the laminate film of the present invention contains an epoxy resin composition composed of the above epoxy resin and an epoxy resin curing agent as a main component. The content of the epoxy composition in the adhesive is preferably more than at least 50% by mass, more preferably 80 to 100% by mass, and still more preferably 90 to 100% by mass.
The blending ratio of the epoxy resin and the epoxy resin curing agent in the epoxy resin composition may be a standard blending range in the case of obtaining an epoxy resin cured product by reaction between the epoxy resin and the epoxy resin curing agent. More 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 (number of active hydrogens / number of epoxy groups) is in the range of 0.5 to 5.0. To do. If the blending ratio is 0.5 or more, the remaining unreacted epoxy group does not lower the gas barrier property of the resulting cured product, and if it is 5.0 or less, the remaining unreacted amino group. The group does not reduce the heat and moisture resistance of the resulting cured product.
When the gas barrier property and heat-and-moisture resistance of the resulting cured epoxy resin are particularly taken into consideration, the ratio of the number of active hydrogens in the epoxy resin curing agent to the number of epoxy groups in the epoxy resin (number of active hydrogens / number of epoxy groups) ) Is more preferably in the range of 0.8 to 3.0, and still more preferably in the range of 0.8 to 2.0.
In addition, when considering the expression of a high gas barrier property in a high humidity environment of the obtained 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. It is preferable to be in the range of -1.4.

[Other ingredients]
The adhesive used for the laminate film of the present invention is made of an epoxy resin composition with a thermosetting resin such as a polyurethane resin, a polyacrylic resin, or a polyurea resin, if necessary, within a range not impairing the effects of the present invention. You may mix in the range of 0.1 mass% or more and less than 50 mass% with respect to the whole thing (The total mass of an epoxy resin and an epoxy resin hardening | curing agent, and so on).

  Moreover, in order to improve the wettability to the surface of various base materials or ink layers, a wetting agent such as silicone or an acrylic compound may be added to the adhesive as necessary. Preferred wetting agents include “BYK325”, “BYK331”, “BYK333”, “BYK345”, “BYK340”, “BYK347”, “BYK348”, “BYK350”, “BYK361N”, “BYK380N” available from BYK Chemie. ”,“ BYK381 ”(both are trade names), and the like. When adding these, the range of 0.01-2.0 mass% is preferable with respect to the epoxy resin composition whole quantity.

  In order to improve the adhesiveness of the adhesive layer to various substrates or ink layers, a tackifier such as xylene resin, terpene resin, phenol resin, rosin resin may be added to the adhesive as necessary. Good. When adding these, the range of 0.01-5.0 mass% is preferable with respect to the epoxy resin composition whole quantity.

  To the adhesive, inorganic fillers such as silica, alumina, mica, talc, aluminum flakes and glass flakes are added in order to improve various properties such as gas barrier properties, impact resistance and heat resistance of the adhesive layer. May be. In consideration of the transparency of the film, the inorganic filler is preferably flat. When adding these, the range of 0.01-10.0 mass% is preferable with respect to the epoxy resin composition whole quantity.

  Moreover, you may add the compound etc. which have an oxygen capture | acquisition function to the said adhesive agent as needed. Examples of compounds having an oxygen scavenging function 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, Examples include transition metal compounds such as copper.

Furthermore, in order to improve the adhesiveness of the adhesive layer to the substrate, ink layer, sealant layer, and other layers, a coupling agent such as a silane coupling agent or a titanium coupling agent is added to the adhesive. May be.
As the coupling agent, commercially available ones can be used. Among them, N- (2-aminoethyl) available from Chisso Corporation, Toray Dow Corning Corporation, Shin-Etsu Chemical Co., Ltd., etc. -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N, N'-bis [3 -Trimethoxysilyl] propyl] amino silane coupling agents such as ethylenediamine, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Epoxy series such as silane and 3-glycidoxypropyltriethoxysilane Run coupling agents, methacryloxy silane coupling agents such as 3-methacryloxypropyltrimethoxysilane, mercapto silane coupling agents such as 3-mercaptopropyltrimethoxysilane, and isocyanate silanes such as 3-isocyanatopropyltriethoxysilane Coupling agents, aminosilane coupling agents such as “SH-6026” and “Z-6050” (both trade names) manufactured by Toray Dow Corning Co., Ltd., “KP-390” manufactured by Shin-Etsu Chemical Co., Ltd. It is desirable to have an organic functional group capable of reacting with the epoxy resin composition, such as an amino group-containing alkoxysilane such as “KC-223” (both trade names).
When adding these, the addition amount has the preferable range of 0.01-5 mass parts with respect to 100 mass parts of total amounts of an epoxy resin and an epoxy resin hardening | curing agent.

The adhesive layer formed by the adhesive has suitable adhesiveness to various substrates, ink layers, sealant layers, and other layers.
The final thickness of the adhesive layer in the laminate film is preferably 0.1 to 100 μm, more preferably 0.5 to 10 μm. Within the above range, an adhesive layer having a uniform thickness can be formed without deteriorating gas barrier properties and adhesiveness.

(Sealant layer)
As a material for the sealant layer in the laminate film of the present invention, it is preferable to use a flexible polymer. In view of heat seal strength, polyolefins such as low density polyethylene, linear low density polyethylene, and polypropylene, and ethylene-vinyl acetate copolymers are more preferable. The thickness of the sealant layer is preferably about 10 to 300 μm, more preferably about 10 to 100 μm. The surface of the sealant layer may be subjected to surface treatment such as flame treatment or corona discharge treatment.

[Production method of laminate film]
Hereinafter, the manufacturing method of the laminate film of this invention is demonstrated.
When forming an ink layer on a base material, it is preferable to perform surface treatments such as flame treatment and corona discharge treatment on the surface of the base material as necessary so that defects such as film breakage and repellency do not occur. The ink layer is formed by a general printing facility that has been used for printing on a conventional polymer film such as a gravure printing machine, a flexographic printing machine, and an offset printing machine. The ink layer may be continuous (full surface printing) or intermittent (partial printing).

  As a method for forming the primer layer, a general dry lamination method can be used. In this case, use a dry laminator to form a primer layer, wind up the substrate once, and then laminate the adhesive and sealant layer again with the same dry laminator, or use an inline coated dry laminator inline. There are continuous methods of forming a primer layer and dry laminating a sealant layer using an adhesive. When providing an ink layer on a base material, it becomes possible to form a primer layer on an ink layer continuously in-line by using a general printing facility, so that the primer application step can be reduced.

When a primer layer is formed on a substrate by a general dry laminating method, a solution in which the primer composition described above is dissolved in a solvent (hereinafter also referred to as “primer solution”) is prepared. A method of applying to a substrate is used.
The solvent used in the primer solution may be any solvent that can dissolve the primer composition. For example, water-insoluble solvents such as toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, Glycol ethers such as 1-ethoxy-2-propanol and 1-propoxy-2-propanol, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol, acetaldehyde, propionaldehyde and the like Aldehydes, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, and other aprotic polar solvents.
In order to reduce the amount of solvent remaining in the primer layer obtained, selected from the group consisting of methanol, ethanol, 2-propanol, and 1-propanol, ethyl acetate, acetone, methyl ethyl ketone, acetaldehyde, propionaldehyde having a relatively low boiling point One kind or a mixed liquid in which two or more kinds are mixed is preferably used.

As a coating method for applying the primer solution, any of commonly used coating methods such as roll coating, spray coating, air knife coating, dipping, and brush coating can be used. Of these, roll coating is preferred. After applying the primer solution to the substrate with a roll such as a gravure roll or a solid roll, the substrate on which the primer layer is formed can be obtained by drying the solvent.
The primer solution preferably has a Zahn cup (No. 3) viscosity in the range of 5 to 30 seconds (25 ° C.). If the Zahn cup (No. 3) viscosity is 5 seconds or more, the primer solution is sufficiently applied to the substrate, and the roll is not contaminated. Moreover, if this Zahn cup (No. 3) viscosity is 30 seconds or less, a primer solution will fully transfer to a roll and a uniform primer layer can be formed. For example, in the dry laminating method, the Zahn cup (No. 3) viscosity of the primer solution is preferably 10 to 20 seconds (25 ° C.) during use.

When the solvent is used in the primer solution, it is preferable to perform a step of drying the solvent after applying the primer solution.
The solvent drying temperature may be any temperature that is close to the boiling point of the solvent and does not affect the substrate, and is preferably in the range of 20 to 140 ° C. When the drying temperature is 20 ° C. or higher, the amount of solvent remaining in the laminate film is small, and adhesion failure and odor generation can be avoided. Moreover, if it is 140 degrees C or less, the softening of a base material etc. will not generate | occur | produce easily and the laminate film of a favorable external appearance can be obtained. For example, when the primer solution is applied to a stretched polypropylene film as a substrate, the drying temperature is preferably 40 to 120 ° C.

  When a primer layer is formed on the ink layer, the primer layer preferably covers the entire surface of the ink layer. In the portion where the ink layer is not formed, the primer layer may be directly formed on the substrate.

The adhesive layer can be formed by a known laminating method such as dry lamination, non-solvent lamination, and extrusion lamination.
The adhesive for forming the adhesive layer is diluted with a solvent and / or water so as to have an epoxy resin composition concentration of about 5% by mass, if necessary, to form an adhesive solution. Applied to the layer.

The solvent used in the adhesive solution is preferably an organic solvent containing an alcohol having a high solubility of the adhesive and a relatively low boiling point and containing an alcohol having 3 or less carbon atoms, such as methanol, ethanol, isopropanol, and n- The solvent which has as a main component 1 or more types chosen from the group which consists of propanols is illustrated.
Furthermore, the above-mentioned solvent delays the reaction between the epoxy resin and the epoxy resin curing agent, and has an effect of suppressing a rapid thickening of the adhesive solution, and has a functional group of any one of an ester group, a ketone group, and an aldehyde group. A mixed solution containing a system solvent is preferred. Examples of the carbonyl solvent include one or more compounds selected from the group consisting of ethyl acetate, acetone, methyl ethyl ketone, acetaldehyde, and propionaldehyde having a relatively low boiling point.
From the viewpoint of obtaining a laminated film with a small amount of residual solvent, the content of the carbonyl solvent is preferably 20% by mass or less in the total solvent in the adhesive solution.

  The adhesive solution preferably has a Zahn cup (No. 3) viscosity in the range of 5 to 30 seconds (25 ° C.). If the Zahn cup (No. 3) viscosity is 5 seconds or more, the adhesive solution is sufficiently applied onto the substrate and / or the ink layer, and the roll is not contaminated. Moreover, if a Zahn cup (No. 3) viscosity is 30 seconds or less, an adhesive will fully transfer to a roll and a uniform adhesive layer can be formed. For example, in dry lamination, the Zahn cup (No. 3) viscosity of the adhesive solution is preferably 10 to 20 seconds (25 ° C.) during use.

When preparing the adhesive solution, an antifoaming agent such as silicone or an acrylic compound may be added to the adhesive solution in order to suppress foaming of the adhesive solution.
Preferred antifoaming agents include “BYK019”, “BYK052”, “BYK065”, “BYK066N”, “BYK067N”, “BYK070”, “BYK080” (all of which are trade names) available from Big Chemie. However, “BYK065” is particularly preferable. Moreover, when adding these antifoamers, the range of 0.01-5.0 mass% is preferable with respect to the epoxy resin composition whole quantity in an adhesive agent solution, 0.02-3.0 mass% A range is more preferred.

Moreover, when a solvent is used in the adhesive solution, it is preferable to perform a step of drying the solvent after applying the adhesive solution.
The solvent drying temperature may be any temperature that is close to the boiling point of the solvent and does not affect the substrate, and is preferably in the range of 20 to 140 ° C. When the drying temperature is 20 ° C. or higher, the amount of solvent remaining in the laminate film is small, and adhesion failure and odor generation can be avoided. Moreover, if it is 140 degrees C or less, the softening of a base material etc. will not generate | occur | produce easily and the laminate film of a favorable external appearance can be obtained. For example, when apply | coating a primer solution to the extending | stretching polypropylene film which is a base material, this drying temperature has preferable 40-120 degreeC.

  As a coating method when applying the adhesive solution, general printing equipment and roll coating and spray coating, which have been used for printing on conventional polymer films such as gravure printing machines, flexographic printing machines, offset printing machines, etc. Any of coating methods such as air knife coating, dipping, brush coating, and die coating can be used, and a printing machine or roll coating is preferable. For example, a gravure printing machine or roll coater and equipment similar to those used for applying gravure ink to a polymer film can be applied.

Next, specific operations in each laminating method will be described.
In the case of the dry laminating method, the primer layer is formed on the base material and / or the ink layer by the above-described method, and then the adhesive solution is roll-coated with a gravure roll or the like, then the solvent is removed, and the surface immediately A laminate film can be obtained by adhering a sealant layer to each other by a nip roll. The temperature of the nip roll at the time of bonding is preferably 20 to 120 ° C, more preferably 40 to 100 ° C.

  After laminating the sealant layer, it is preferable to perform aging at 20 to 60 ° C. for a certain time as necessary to complete the curing reaction of the epoxy resin composition contained in the adhesive layer. By the aging, a cured epoxy resin is formed with a sufficient reaction rate. If the cured epoxy resin has a gas barrier property, a high gas barrier property is exhibited. When the aging is 20 ° C. or higher, the reaction rate of the epoxy resin composition contained in the adhesive layer is improved, and sufficient adhesiveness and gas barrier properties are obtained. Moreover, if it is 60 degrees C or less, problems, such as blocking of a base material or a sealant layer, and elution of an additive, will not occur easily.

  In the dry laminating method, a laminate film can be produced by forming each layer in the reverse order as described above. That is, after applying the adhesive solution to a polyolefin film such as a polyethylene film or polypropylene film forming a sealant layer, or an ethylene-vinyl acetate copolymer film and drying to form an adhesive layer, if necessary, After forming the ink layer, a laminate film can be produced by laminating substrates such as stretched polypropylene, polyamide film, and polyethylene terephthalate film.

  When the base material on which the ink layer is formed is bonded by a nip roll, the nip roll temperature is preferably 20 to 120 ° C, more preferably 40 to 100 ° C.

  In the case of the non-solvent laminating method, after the adhesive previously heated to about 40 to 100 ° C. is applied to the substrate on which the ink layer is formed by a roll such as a gravure roll heated to 40 to 120 ° C. A laminate film can be obtained by immediately pasting a sealant layer on the surface. In this case as well, as in the dry laminating method, it is desirable to perform aging for a certain period of time as needed after laminating.

In the case of the extrusion laminating method, the adhesive solution is applied to the substrate on which the ink layer is formed by a roll such as a gravure roll, and after drying and curing reaction of the solvent at 20 to 140 ° C., the melt is obtained by an extruder. A laminated film can be obtained by laminating the sealant layer.
The above laminating method and other general laminating methods can be combined as necessary.

The laminate film of the present invention is preferably produced by a dry lamination method.
Further, the laminate film of the present invention preferably has a laminate strength (initial adhesive force) at a peeling speed of 300 mm / min immediately after lamination (before aging) of 30 g / 15 mm or more, and 40 g / 15 mm or more. More preferably, it is still more preferably 50 g / 15 mm or more. If this initial adhesive force is sufficient, problems such as tunneling of the laminate film and winding deviation at the time of winding the film will not occur.

  The laminate strength measured by the peel strength of 300 mm / min of the laminate film of the present invention 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 / It is more preferably 15 mm or more, and further preferably 120 g / 15 mm or more. When the base material is stretched nylon or polyethylene terephthalate, if the sealant layer is low-density polyethylene, 600 g / 15 mm or more is preferable, 700 g / 15 mm or more is more preferable, and 800 g / 15 mm or more is more preferable. If it is unstretched polypropylene, 300 g / 15 mm or more is preferable, 400 g / 15 mm or more is more preferable, More preferably, it is 500 g / 15 mm or more.

Further, since the odor decreases as the residual solvent amount in the laminate film decreases, the residual solvent amount in the laminate film of the present invention is preferably 40 mg / m ² or less. To prevent the occurrence of odors more reliably, more preferably not more than 20 mg / m ^2, more preferably 10 mg / m ² or less, 3 mg / m ² or less is particularly preferred.

  The laminate film of the present invention can be used as a multilayer packaging material for the purpose of protecting foods and pharmaceuticals. You may change the layer structure of a multilayer packaging material according to the kind of preserve | saved goods, use environment, and a use form. For example, the laminate film of the present invention can be used as a multilayer packaging material as it is, and an optional layer such as an oxygen absorbing layer, a thermoplastic resin film layer, a paper layer, or a metal foil layer can be used as needed. The film can be further laminated. The arbitrary layer may be laminated using the adhesive in the present invention, or may be laminated using another adhesive or an anchor coat agent.

  The laminated film of the present invention may be formed by packaging the two sealant layers by folding or superimposing them after forming or without forming the optional layer, and then heat-sealing the peripheral edge to form a packaging bag. Can do. Heat seal forms include, for example, side seals, two-sided seals, three-sided seals, envelope stickers, joint seals (pillow seals), flat bottom seals, square bottom seals, gusset seals, etc. Chosen according to In addition, for example, a self-supporting packaging bag (standing pouch) can be used. Examples of the heat seal method include known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high frequency seal, and ultrasonic seal.

  After filling the packaging bag with the contents, the opening can be heat sealed to produce a packaged product using the laminate film of the present invention. Contents to be preserved include rice crackers, bean confectionery, nuts, biscuits and cookies, wafer confectionery, marshmallows, pies, half-baked cakes, candy, snack confectionery and other confectionery, bread, snack noodles, instant noodles, dried noodles, pasta , Aseptic packaging rice, elephant rice, porridge, packaging rice cake, staples such as cereal foods, pickles, boiled beans, natto, miso, frozen tofu, tofu, licked rice, konjac, wild vegetable products, jams, peanut cream, salads, frozen Agricultural processed products such as vegetables, potato processed products, hams, bacon, sausages, chicken processed products, livestock processed products such as corned beef, fish ham and sausages, marine products, kamaboko, paste, boiled bonito, salted fish, Seafood products such as smoked salmon and 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 will be described below, but the present invention is not limited to these examples.

Each measurement and evaluation was performed by the following method.
(1) Oxygen permeability coefficient (ml · mm / (m ² · day · MPa))
Using an oxygen permeability measuring device (trade name “OX-TRAN10 / 50A” manufactured by Modern Control Co., Ltd.), the oxygen permeability coefficient of the laminate film was measured under the conditions of 23 ° C. and relative humidity 60%, and cured with epoxy resin. The oxygen permeability coefficient of the object (adhesive layer) was calculated using the following formula. A higher oxygen permeability coefficient indicates a lower oxygen barrier property.
1 / R ₁ = 1 / R ₂ + 1 / R ₃ + 1 / R ₄ + DFT / P
R ₁ : Oxygen permeability of laminated film (ml / m ² · day · MPa)
R ₂ : Oxygen permeability of substrate (ml / m ² · day · MPa)
R ₃ ; oxygen permeability of the primer layer (ml / m ² · day · MPa)
R ₄ ; oxygen permeability of the sealant layer (ml / m ² · day · MPa)
DFT: Thickness (mm) of cured epoxy resin (adhesive layer)
P: Oxygen transmission coefficient (ml · mm / m ² · day · MPa) of cured epoxy resin (adhesive layer)

(2) Laminate 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.

(3) Heat seal strength (kg / 15mm)
The sealant layers of the two laminate films are heat sealed at 2 kg / cm ² , 1 second, 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.

(4) Residual solvent amount (mg / m ² )
200 laminated film pieces (25 cm × 1 cm) were placed in an Erlenmeyer flask and heated at 80 ° C. for 30 minutes, and then the solvent concentration of air in the flask was analyzed by GC. From the results, the amount of residual solvent per 1 m ^{2 of} laminate film was calculated.

<Production Example 1> Epoxy resin curing agent A
A reaction vessel was charged with 1 mol of metaxylylenediamine and heated to 60 ° C. under a nitrogen stream. 0.93 mol of methyl acrylate was dripped here 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. Subsequently, this was cooled to 100 degreeC, methanol was added so that solid content concentration might be 70 mass%, and the epoxy resin hardening | curing agent A diluted with methanol was obtained. The content (based on solid content) of the amide group in the epoxy resin curing agent A was 21% by mass.

<Preparation Example 1> Primer solution A1
Polyester resin (trade name “Byron UR-1700” manufactured by Toyobo Co., Ltd., acid value = 26 KOHmg / g, Tg = 92 ° C.) is diluted with methyl ethyl ketone to obtain a primer solution A1 having a solid content concentration of 10 mass%. Prepared.

<Preparation Example 2> Primer solution A2
Polyester resin (manufactured by Toyobo Co., Ltd., trade name “Byron UR-3500”, acid value = 35 KOH mg / g, Tg = 10 ° C.) is diluted with methyl ethyl ketone to obtain a primer solution A2 having a solid content concentration of 10 mass%. Prepared.

<Preparation Example 3> Primer solution B1
Polyester resin (trade name “Byron 200” manufactured by Toyobo Co., Ltd., acid value <2 KOHmg / g, Tg = 67 ° C.) and isocyanate curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”) ”) Under the conditions of a blending equivalent ratio of 1 (where the blending equivalent ratio refers to the ratio of the OH equivalent of Byron 200 to the NCO equivalent of Coronate L (OH equivalent / NCO equivalent)) and diluted with ethyl acetate. A primer solution B1 having a solid content concentration of 10% by mass was prepared.

<Preparation Example 4> Primer solution B2
Polyester resin (trade name “Byron GK640” manufactured by Toyobo Co., Ltd., acid value <4 KOHmg / g, Tg = 79 ° C.) and isocyanate curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”) ) At a compounding equivalent ratio of 1 (where the compounding equivalent ratio refers to the ratio of OH equivalent of Byron GK640 to NCO equivalent of Coronate L (OH equivalent / NCO equivalent)), diluted with ethyl acetate, Primer solution B2 having a solid content concentration of 10% by mass was prepared.

<Example 1>
50 parts by mass of an epoxy resin having a glycidylamino group derived from metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd., trade name “TETRAD-X”), 150 parts by mass of epoxy resin curing agent A, and 210 of methanol Into a mixed liquid (methanol / ethyl acetate = 9/1, solid content concentration: 35% by mass) obtained by mixing and stirring well with 29 parts by mass of ethyl acetate and ethyl acetate, 0.05 parts by mass of trade name “BYK065” manufactured by Big Chemie Co., Ltd.) was added and stirred well to obtain an adhesive solution 1 having a Zahn cup (No. 3) viscosity of 14 seconds (25 ° C.).
Next, a solution obtained by mixing the primer solution A1 obtained in Preparation Example 1 and the primer solution B1 obtained in Preparation Example 3 in a ratio of 1 to 2 (mass ratio) is used as a base material having a stretch of 6 μm. After applying onto a nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) using a gravure roll with 200 lines / cm and a depth of 38 μm, 60 ° C. (near the inlet) to 90 ° C. (near the outlet) In the drying oven, a primer layer was formed on the substrate.
On this primer layer, the adhesive solution 1 is applied using a gravure roll of 100 lines / cm and a depth of 100 μm, and dried and dried in a drying oven at 60 ° C. (near the inlet) to 90 ° C. (near the outlet). An agent layer was formed. A 40 μm-thick linear polyethylene film (manufactured by Tosero Co., Ltd., trade name “TUX MC-S”) as a sealant layer is bonded to the adhesive layer by a nip roll heated to 70 ° C., A laminate film was obtained by winding at a winding speed of 130 m / min and aging the roll at 40 ° C. for 2 days.
About the obtained laminate film, the oxygen permeability coefficient of the adhesive layer (cured epoxy resin), the initial strength and the laminate strength and heat seal strength after 6 months, and the amount of residual solvent were evaluated. The results are shown in Table 1. In addition, the content rate of the frame | skeleton structure shown by the said General formula (1) in an adhesive bond layer (epoxy resin hardened | cured material) was 59.9 mass%.

<Example 2>
A laminate film was produced in the same manner as in Example 1 except that instead of the adhesive solution 1, an adhesive solution 2 using 210 parts by mass of ethanol instead of 210 parts by mass of methanol was used. . The results are shown in Table 1.

<Example 3>
A laminate film was produced in the same manner as in Example 1 except that the mixing ratio of the primer solution A1 and the primer solution B1 was 1: 3 (mass ratio). The results are shown in Table 1.

<Example 4>
A laminate film was produced in the same manner as in Example 1 except that the mixing ratio of the primer solution A1 and the primer solution B1 was 1: 1 (mass ratio). The results are shown in Table 1.

<Example 5>
A laminate film was produced in the same manner as in Example 1 except that the primer solution B2 obtained in Preparation Example 4 was used instead of the primer solution B1. The results are shown in Table 1.

<Example 6>
A laminate film was produced in the same manner as in Example 1 except that the primer solution A2 obtained in Preparation Example 2 was used instead of the primer solution A1. The results are shown in Table 1.

<Example 7>
A laminate film was produced in the same manner as in Example 1 except that only the primer solution A1 was used without using the primer solution B1. The results are shown in Table 1.

<Example 8>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 1. The results are shown in Table 1.

<Example 9>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 2. The results are shown in Table 1.

<Example 10>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 3. The results are shown in Table 1.

<Example 11>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 4. The results are shown in Table 1.

<Example 12>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 5. The results are shown in Table 1.

<Example 13>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 6. The results are shown in Table 1.

<Example 14>
A white ink layer was printed on the entire upper surface of a stretched 6-nylon film (trade name “Harden N1102” manufactured by Toyobo Co., Ltd.) having a thickness of 15 μm as a base material, and a primer layer was formed on the ink layer. Produced a laminate film in the same manner as in Example 7. 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 only the primer solution B1 was used without using the primer solution A1. The results are shown in Table 1.

<Comparative example 2>
A laminate film was produced in the same manner as in Example 5 except that only the primer solution B2 was used without using the primer solution A1. The results are shown in Table 1.

<Comparative Example 3>
A laminate film was produced in the same manner as in Example 8 except that only the primer solution B1 was used without using the primer solution A1. The results are shown in Table 1.

<Comparative example 4>
A laminate film was produced in the same manner as in Example 12 except that only the primer solution B2 was used without using the primer solution A1. The results are shown in Table 1.

<Comparative Example 5>
A laminate film was produced in the same manner as in Example 8 except that the primer layer was not formed. The results are shown in Table 1.

The laminate film of the present invention has excellent adhesiveness over time, and can maintain excellent laminate strength and heat seal strength even when stored for a long period of time.
Further, even when a base material containing polyamide is used as the base material constituting the laminate film, the drying property of the solvent is good, which is advantageous in terms of workability in the manufacturing process. Further, the laminate film has an excellent laminate strength even when printed on a substrate, and can be used as a multilayer packaging material for the purpose of protecting foods and pharmaceuticals.

Claims (8)

A laminate film in which at least a base material, a primer layer, an adhesive layer, and a sealant layer are laminated in this order, and the primer composition forming the primer layer has an acid value of 10 to 35 KOHmg / g and glass The adhesive containing the polyester resin (a) having a transition temperature of -20 to 120 ° C. and 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 characterized by being.   The laminate film according to claim 1, wherein the content of the polyester resin (a) in the primer composition is 5 to 100% by mass.   The laminate film according to claim 1 or 2, wherein the primer composition further comprises a polyester resin (b) having an acid value of less than 10 KOHmg / g and a glass transition temperature of -20 to 120 ° C.   The mixing ratio [(a) / (b)] of the polyester-based resin (a) and the polyester-based resin (b) contained in the primer composition is greater than 0.1 by mass ratio. 3. Laminated film according to 3. The laminate film according to any one of claims 1 to 4, wherein the cured epoxy resin obtained by curing the epoxy resin composition contains 40% by mass or more of a skeleton structure represented by the following general formula (1).

  The laminate film according to any one of claims 1 to 5, wherein the substrate is a substrate containing at least polyamide. The laminate film according to any one of claims 1 to 6, wherein the adhesive layer has an oxygen barrier property having an oxygen permeability coefficient at 23 ° C and 60% RH of 1.0 ml · mm / m ² · day · MPa or less. .   The laminate film according to any one of claims 1 to 7, which is produced by a dry lamination method.