JP6162410B2 - LAMINATE FOR PACKAGING MATERIAL, PROCESS FOR PRODUCING THE SAME AND PACKAGING MATERIAL - Google Patents

Description

  The present invention relates to a laminate for packaging material and a packaging material using the same, and particularly relates to a packaging material having excellent content resistance.

  Thermoplastic resin films typified by polyester resin films and polyamide resin films are excellent in mechanical properties, processability, etc., and are relatively inexpensive, and are therefore widely used in a wide range of applications. Thermoplastic resin films are suitable for packaging materials and are indispensable in daily life. When a thermoplastic resin film is used as a packaging material, in many cases, a layer made of a sealant resin having heat sealing properties such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer is laminated on at least one surface of the film. The film has heat sealability.

  As a method of laminating such a sealant resin on a thermoplastic resin film, the thermoplastic resin film and the sealant resin film are mainly bonded to an adhesive layer (the adhesive layer is generally called an anchor coat layer, a primer layer, etc. In general, dry lamination is used, and an adhesive layer is formed on the thermoplastic resin film, and the melted sealant resin is extruded onto the adhesive layer and then cooled, solidified, and laminated. Has been. In particular, the extrusion laminating method can ensure good adhesiveness even if the adhesive layer is thin, and it is low cost because the raw material resin is extruded directly onto the thermoplastic resin film without using a sealant resin film. It is preferred.

  A thermoplastic resin film on which such a sealant layer is laminated is used as a packaging material for wrapping various contents. However, if volatile substances such as menthol and naphthalene, scent components such as limonene, medicinal components or battery electrolytes are used as the contents, the contents themselves or the The adhesive layer between the thermoplastic resin film and the sealant layer may swell or dissolve depending on the components contained, and this causes the adhesive strength between the thermoplastic resin film and the sealant layer to deteriorate over time, and hence adhesion. There was a problem that both layers peeled off due to strength reduction (delamination). Therefore, in order to solve such problems, Patent Documents 1 and 2 propose packaging materials with improved adhesive strength of the sealant layer.

JP 2008-120062 JP JP 2010-5802 A

  However, although Patent Document 1 describes a technique for suppressing a decrease in adhesive strength between a barrier layer made of aluminum foil or the like and a sealant layer, a general thermoplastic resin film and a sealant layer There is no description on how to suppress the decrease in the adhesive strength during heating.

  On the other hand, Patent Document 2 proposes a technique for suppressing a decrease in adhesive strength between a thermoplastic resin film and a sealant layer. However, when the packaging material described in the document is heat-sealed, fine wrinkles may occur at the boundary portion, and the appearance as a packaging material may be deteriorated. In addition, it is generally desired that the adhesive layer used for the packaging material has little adsorption of the content components, but the adhesive layer described in Patent Document 2 leaves room for improvement in the adsorptivity of the content components. Yes.

  Furthermore, in the invention described in Patent Document 2, the adhesive layer is formed by applying an aqueous dispersion using a known coater such as a gravure coater. Various types of coating materials such as water-based coating materials and solvent-based coating materials are applied to coaters used in general manufacturing sites, and are replaced and used every time depending on the purpose of use. However, when this coating material is replaced, even if a small amount of water-insoluble solvent remains in the coating material storage tank, coating material supply line, coating material supply pan, etc. provided with the coater, fine aggregates will form in the aqueous dispersion. There is a problem that even if such an aqueous dispersion is used, it is difficult to uniformly apply it to the thermoplastic resin film. That is, the aqueous dispersion described in the cited document 2 has a problem in dispersion stability when a water-insoluble solvent (for example, toluene) is mixed.

  The present invention solves the above-mentioned problems, and when processed into a packaging material, the contents that are likely to cause a decrease in adhesive strength between the thermoplastic resin film and the sealant layer can be packaged. A laminate for a packaging material in which not only the adhesive strength is hardly lowered but also a wrinkle is hardly generated in a heat seal boundary part, and an adhesive layer hardly adsorbs contents components, a method for efficiently obtaining the laminate, and the laminate It aims at providing the packaging material processed using.

  As a result of intensive studies to solve the above problems, the present inventors have used an adhesive layer containing an acid-modified polyolefin resin, polyvinyl alcohol, and a crosslinking agent in a specific ratio, and this is a thermoplastic resin film. It was found that the laminate for packaging material obtained by laminating between the adhesive layer and the sealant layer solves the above-mentioned problems, and has reached the present invention.

  That is, the gist of the present invention is as follows.

(1) A laminate in which a thermoplastic resin film, an adhesive layer and a sealant layer are laminated at least in this order, wherein the adhesive layer is an acid-modified polyolefin resin (A), polyvinyl alcohol (B) and a crosslinking agent (C). And 0.1 to 10 parts by mass of polyvinyl alcohol (B) with respect to 100 parts by mass of the acid-modified polyolefin resin (A), and a total amount of (A) and (B) of 100 parts by mass ( A laminate for packaging material comprising 0.1 to 30 parts by mass of a crosslinking agent (C) relative to A + B).
(2) The adhesive layer is a coating film obtained from an aqueous dispersion containing an acid-modified polyolefin resin (A), polyvinyl alcohol (B), a crosslinking agent (C) and an aqueous medium (1) ) The laminate for packaging materials described.
(3) The laminate for packaging materials according to (1) or (2), wherein the thermoplastic resin film is a polyester resin film or a polyamide resin film.
(4) The laminate for packaging material according to any one of (1) to (3), wherein the crosslinking agent (C) is an oxazoline-based crosslinking agent and / or a carbodiimide-based crosslinking agent.
(5) A packaging material obtained by heat-sealing the laminate for packaging material according to any one of (1) to (4).
(6) A method for producing a laminate in which a molten sealant resin is laminated by extrusion lamination on a thermoplastic resin film through an adhesive layer, wherein the adhesive layer is an acid-modified polyolefin resin (A), polyvinyl alcohol. (B) and a crosslinking agent (C) are contained, and the polyvinyl alcohol (B) is contained in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A). The manufacturing method of the laminated body for packaging materials characterized by containing 0.1-30 mass parts of crosslinking agents (C) with respect to 100 mass parts (A + B) of the total amount of (B).
(7) The adhesive layer is a coating film obtained from an aqueous dispersion containing an acid-modified polyolefin resin (A), polyvinyl alcohol (B), a crosslinking agent (C) and an aqueous medium (6) The manufacturing method of the laminated body for packaging materials of description.

  The packaging material of the present invention reduces the adhesive strength between the thermoplastic resin film and the sealant layer even if the contents that tend to cause a decrease in the adhesive strength between the thermoplastic resin film and the sealant layer are stored for a long period of time. (Hereinafter, such an effect may be referred to as “content resistance performance”). Furthermore, it is difficult for wrinkles to approach the heat seal boundary. Moreover, since there is little adsorption | suction of a content component, a content can also be preserve | saved favorably for a long time. And since the aqueous dispersion used when manufacturing the laminated body for packaging materials of this invention is excellent in dispersion stability even if a water-insoluble solvent is mixed, the replacement | exchange operation | work of a coating material can be performed smoothly. This is also advantageous in forming a uniform adhesive layer.

  Hereinafter, the present invention will be described in detail.

  The laminate for packaging material of the present invention is a packaging material in which a thermoplastic resin film, an adhesive layer and a sealant layer are laminated in at least this order.

  As the thermoplastic resin film in the present invention, those produced using various thermoplastic resins as raw materials can be used. Examples of the thermoplastic resin include polyester resins such as polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and mixtures thereof; polycapronamide (hereinafter “ Polyamide resins such as nylon 6 ”or“ Ny6 ”), polyhexamethylene adipamide (nylon 66), poly-p-xylylene adipamide (MXD6 nylon), and mixtures thereof; polyethylene And polyolefin resins such as polypropylene and mixtures thereof. Among these, a polyester resin and a polyamide resin are preferable, and PET and Ny6 are particularly preferable because they can give excellent mechanical properties to the packaging material.

  As the thermoplastic resin film, a film produced by a publicly known method can be used, and it may be either an unstretched film or a stretched film. However, it is uniaxial or biaxial from the viewpoint of imparting transparency and gloss. An axially stretched film is preferable, and a biaxially stretched film is more preferable. The thickness of the film is not particularly limited, and usually 5 to 500 μm is used.

  The thermoplastic resin film is preferably subjected to surface activation treatment on the surface on which the adhesive layer is provided in order to improve adhesiveness. Examples of the surface activation treatment include corona discharge treatment, flame plasma treatment, atmospheric pressure plasma treatment, low pressure plasma treatment, ozone treatment, electron beam irradiation treatment, ultraviolet irradiation treatment, chemical treatment, and solvent treatment. Corona discharge treatment is preferred from the balance of the adhesion effect.

  The adhesive layer in the present invention contains an acid-modified polyolefin resin (A), polyvinyl alcohol (B), and a crosslinking agent (C).

  The olefin component which is the main component of the acid-modified polyolefin resin (A) is not particularly limited, but alkene having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene and the like. Are preferred, and a mixture thereof may be used. Among these, from the viewpoint of further improving adhesiveness, alkenes having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene, and 1-butene are more preferable, ethylene and propylene are more preferable, and ethylene is most preferable.

  In the present invention, the acid-modified polyolefin resin (A) is a polyolefin resin that has been acid-modified with an unsaturated carboxylic acid component. Examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid, fumaric acid, crotonic acid, and the like, as well as unsaturated dicarboxylic acid half esters and half amides. Among these, acrylic acid, methacrylic acid, and (anhydrous) maleic acid are preferable from the viewpoint of adhesiveness to the thermoplastic resin film, and acrylic acid and (anhydrous) maleic acid are particularly preferable. Moreover, the unsaturated carboxylic acid component should just be copolymerized in acid-modified polyolefin resin, and the form is not specifically limited. Examples of the state of copolymerization include random copolymerization, block copolymerization, and graft copolymerization (graft modification). In addition, “(anhydrous) to acid” means “to acid or anhydrous to acid”. That is, (anhydrous) maleic acid means maleic acid or maleic anhydride.

  The content of the unsaturated carboxylic acid component in the acid-modified polyolefin resin (A) is preferably 0.01 to 10% by mass in view of the balance between the adhesiveness between the thermoplastic resin film and the sealant layer and the content resistance, and the like. 1-5 mass% is more preferable, 0.5-4 mass% is further more preferable, and 1-4 mass% is especially preferable. When the content is less than 0.01% by mass, the adhesiveness tends to be inferior, and further, the processing to an aqueous dispersion described later tends to be difficult. On the other hand, when it exceeds 10% by mass, the adhesiveness and content resistance performance tend to decrease, and further, the stability when mixed with the polyvinyl alcohol (B) described later tends to decrease.

  The acid-modified polyolefin resin (A) preferably contains a (meth) acrylic acid ester component in order to obtain sufficient adhesion between the thermoplastic resin film and the sealant layer. Examples of the (meth) acrylic acid ester component include an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms, and (meth) acrylic acid and carbon number 1 from the viewpoint of easy availability. Esterified products with ˜20 alcohols are preferred. Specific examples of the (meth) acrylic acid ester component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth ) Octyl acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. Mixtures of these may be used. Among these, from the viewpoint of easy availability and adhesiveness, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl acrylate, octyl acrylate are more preferable, ethyl acrylate, More preferred is butyl acrylate, and particularly preferred is ethyl acrylate. ("(Meth) acrylic acid-" means "acrylic acid- or methacrylic acid-".

  The content of the (meth) acrylic acid ester component in the acid-modified polyolefin resin (A) is preferably 0.1 to 25% by mass, and 1 to 20% by mass from the viewpoints of adhesiveness and content resistance. It is more preferable, it is more preferable that it is 2-18 mass%, and it is especially preferable that it is 3-15 mass%. When the content of the (meth) acrylic acid ester component is less than 0.1% by mass, the adhesiveness tends to decrease, and when it exceeds 25% by mass, the content resistance tends to deteriorate. Further, the (meth) acrylic acid ester component may be copolymerized in the acid-modified polyolefin resin, and the form thereof is not limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and grafting. Examples thereof include copolymerization (graft modification).

  Specific examples of the acid-modified polyolefin resin (A) include ethylene- (meth) acryl such as ethylene-ethyl acrylate- (anhydrous) maleic acid copolymer and ethylene-butyl acrylate- (anhydride) maleic acid copolymer. Acid ester- (anhydrous) maleic acid copolymer, ethylene-propylene- (meth) acrylic acid ester- (anhydrous) maleic acid copolymer, ethylene-butene- (meth) acrylic acid ester- (anhydrous) maleic acid copolymer Polymer, propylene-butene- (meth) acrylic acid ester- (anhydrous) maleic acid copolymer, ethylene-propylene-butene- (meth) acrylic acid ester- (anhydrous) maleic acid copolymer, ethylene-acrylic acid copolymer Polymer, ethylene-methacrylic acid copolymer, ethylene-maleic anhydride copolymer, ethylene-propylene- (no ) Maleic acid copolymer, ethylene-butene- (anhydrous) maleic acid copolymer, propylene-butene- (anhydrous) maleic acid copolymer, ethylene-propylene-butene- (anhydrous) maleic acid copolymer, etc. Among them, ethylene- (meth) acrylic acid ester- (anhydride) maleic acid copolymer is most preferable. The form of the copolymer may be any of a random copolymer, a block copolymer, a graft copolymer, and the like, but a random copolymer and a graft copolymer are preferable because they are easily available.

  The ethylene- (meth) acrylic acid ester- (anhydrous) maleic acid copolymer is described in, for example, British Patent No. 2911745, US Pat. No. 4,617,366 and US Pat. No. 4,644,044. By referring to these methods, those skilled in the art can easily produce them.

  The higher the molecular weight of the acid-modified polyolefin resin (A), the better the content resistance of the resulting packaging material. Specifically, the melt flow rate (MFR) at 190 ° C. and 2160 g load, which is a measure of molecular weight, is preferably in the range of 0.001 to 300 g / min, more preferably 0.1 to 100 g / min, 0.5 -50 g / 10 min is more preferred, 1-10 g / 10 min is particularly preferred, and 1-5 g / 10 min is most preferred. When the melt flow rate exceeds 300 g / min, the resistance to physical properties tends to decrease. When the melt flow rate is less than 0.001 g / min, there is a restriction in production when the resin is made high molecular weight.

  In the present invention, the acid-modified polyolefin resin (A) is preferably used as an aqueous dispersion as described later (in this specification, (A), (B), (C) and an aqueous medium. An aqueous dispersion containing a water is referred to as an “aqueous dispersion”). Here, the aqueous dispersion of the acid-modified polyolefin resin (A) will be described. The acid-modified polyolefin resin (A) can be processed into an aqueous dispersion by dispersing it in an aqueous medium. As a dispersion method, a known dispersion method such as a self-emulsification method or a forced emulsification method may be employed.

  The aqueous dispersion of the acid-modified polyolefin resin (A) includes an anionic aqueous dispersion obtained by neutralizing the unsaturated carboxylic acid component of the acid-modified polyolefin resin (A) with a basic compound in an aqueous medium. It is preferable from the viewpoint of adhesiveness.

  The aqueous medium used when the acid-modified polyolefin resin (A) is dispersed in water is a medium composed of water or a liquid containing water, and includes a neutralizing agent that contributes to dispersion stabilization, a water-soluble organic solvent, and the like. It may be. Examples of the water-soluble organic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, Alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, and isophorone; tetrahydrofuran, dioxane, and the like Ethers: ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-sec-butyl, acetic acid-3-methoxybutyl, propio Esters such as methyl acid, ethyl propionate, diethyl carbonate, dimethyl carbonate; ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, Glycol derivatives such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate; Butoxy-3-methyl butanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. In addition, you may use these organic solvents in mixture of 2 or more types. Among these, it is preferable to use a volatile water-soluble organic solvent having a boiling point of 140 ° C. or less because the remaining amount after forming the adhesive layer can be reduced. Specifically, ethanol, n-propanol, isopropanol, n-butanol and the like are preferable.

  Examples of the basic compound used to neutralize the unsaturated carboxylic acid component of the acid-modified polyolefin resin (A) include ammonia, triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, Examples include morpholine, N-methylmorpholine, N-ethylmorpholine, organic amines such as sodium hydroxide and potassium hydroxide, and alkali metals. In addition, you may use a basic compound in mixture of 2 or more types. Among these, it is preferable to use a volatile basic compound having a boiling point of 140 ° C. or less because the remaining amount after forming the adhesive layer can be reduced. Specifically, ammonia, triethylamine, N, N-dimethylethanolamine and the like are preferable.

  In the present invention, the adhesive layer is made of polyvinyl from the viewpoint of suppressing wrinkle generation and content adsorption when used as a packaging material, or suppressing reduction in dispersion stability due to mixing of water-insoluble solvents in an aqueous dispersion described later. It is necessary to contain alcohol (B). As the polyvinyl alcohol (B), a completely or partially saponified polymer of vinyl ester can be used. As the saponification method, a known alkali saponification method or acid saponification method can be employed. Of these, a method of alcoholysis using an alkali hydroxide in methanol is preferred.

  Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate, and the like. Of these, vinyl acetate is most preferred industrially.

  The saponification degree of the polyvinyl alcohol (B) is preferably 80 to 99.9 mol%, more preferably 90 to 99.9 mol%, and still more preferably 95 to 99.9 mol%. When the degree of saponification deviates from the above-mentioned preferable range, when a water-insoluble solvent is mixed in the aqueous dispersion, the dispersion stability tends to be reduced, and the wrinkle suppressing effect of the packaging material tends to be reduced.

  As average polymerization degree of polyvinyl alcohol (B), 100-3000 are preferable, 300-2000 are more preferable, 500-1500 are further more preferable, 500-1000 are especially preferable. If it is less than 100, the content resistance may deteriorate, and if it exceeds 3000, the viscosity of the aqueous dispersion tends to be too high when used as an aqueous dispersion described later.

  Moreover, it is also possible to copolymerize other vinyl compounds with respect to vinyl ester in the range which does not impair the effect of this invention. Other vinyl compounds such as vinyl monomers include unsaturated monocarboxylic acids such as crotonic acid, acrylic acid and methacrylic acid and their esters, salts, anhydrides, amides, nitriles; maleic acid, itaconic acid, fumaric acid Unsaturated dicarboxylic acids and salts thereof such as ethylene; α-olefins having 2 to 30 carbon atoms such as ethylene; alkyl vinyl ethers; vinyl pyrrolidones, diacetone acrylamide, and the like. For example, when ethylene is copolymerized, that is, in the case of an ethylene-vinyl alcohol copolymer, the ethylene content is preferably 50 mol% or less, more preferably 40 mol% or less from the viewpoint of content resistance.

  In addition, as a polyvinyl alcohol (B), a commercially available thing can be used. Specifically, “J-Poval” manufactured by Nippon Vinegar Poval Co., “Kuraray Pobar” and “Exebar” manufactured by Kuraray Co., Ltd., “Denka Poval” manufactured by Denki Kagaku Kogyo Co., Ltd. and the like can be suitably used.

  In the present invention, the polyvinyl alcohol (B) is preferably used as an aqueous solution as described later. The method for dissolving the polyvinyl alcohol (B) in water is not particularly limited. Specific examples include a method of adding polyvinyl alcohol (B) to water, stirring, and heating as necessary.

  Polyvinyl alcohol (B) needs to be contained in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A) in the adhesive layer, preferably 0.1 to 7 parts by mass, 0.5-5 mass parts is more preferable, and 1-3 mass parts is especially preferable. When the content of (B) is less than 0.1 parts by mass, when the laminate is processed into a packaging material, the effect of suppressing the occurrence of wrinkles at the heat seal boundary, and the water-insoluble solvent in the aqueous dispersion Dispersion stability deteriorates when is mixed. Further, the adhesive layer tends to easily adsorb the content components. On the other hand, when it exceeds 10 mass parts, the adhesiveness of a thermoplastic resin film and a sealant layer falls.

  Furthermore, the adhesive layer in the present invention needs to contain a crosslinking agent (C) for the purpose of further improving the adhesiveness, content resistance performance, wrinkle suppressing effect of the packaging material, and the like. In the present invention, the crosslinking agent (C) can form a crosslinked structure of (A) and / or (B) by reacting with the acid-modified polyolefin resin (A) and / or polyvinyl alcohol (B). It is a simple compound. Specific examples include compounds containing a plurality of functional groups capable of reacting with the functional groups contained in (A) and / or (B) in the molecule. More specifically, polyvalent oxazoline compound, polyvalent carbodiimide compound, polyvalent hydrazide compound, polyvalent isocyanate compound, polyvalent isocyanate compound, polyvalent melamine compound, polyvalent urea compound, polyvalent epoxy compound, polyvalent amine compound These crosslinking agents may be used in combination. Among these crosslinking agents, a polyvalent oxazoline compound and a polyvalent carbodiimide compound are preferable from the viewpoint of further improving adhesiveness, content resistance performance, wrinkle suppression effect of packaging materials, and the like. Furthermore, the crosslinking agent may be a low molecular weight compound or a polymer type.

  In the present invention, the crosslinking agent (C) is preferably used as an aqueous solution or an aqueous dispersion as described later. That is, the crosslinking agent (C) is preferably water-soluble or water-dispersible. The method for processing the crosslinking agent (C) into an aqueous solution or an aqueous dispersion is not particularly limited, and a known method can be adopted.

  Examples of the aqueous solution or aqueous dispersion of the polyvalent oxazoline compound include “Epocross (registered trademark)” manufactured by Nippon Shokubai Co., Ltd. The aqueous solution or aqueous dispersion of the polyvalent carbodiimide compound includes, for example, “Nisshinbo Chemical Co., Ltd.” Carbodilite (registered trademark) ". In any case, commercially available products can be used.

  The crosslinking agent (C) must be contained in the range of 0.1 to 30 parts by mass with respect to 100 parts by mass (A + B) of the total amount of (A) and (B) in the adhesive layer, and 0.2 to 20 The range of parts by mass is preferable, the range of 0.3 to 10 parts by mass is more preferable, and the range of 0.5 to 5 parts by mass is particularly preferable. When the crosslinking agent (C) is out of the above range, performance such as adhesiveness, content resistance performance, and wrinkle suppression of the packaging material may be deteriorated.

  The thickness of the adhesive layer in the present invention is preferably in the range of 0.01 to 10 μm, more preferably 0.05 to 5 μm, particularly preferably 0.1 to 2 μm, and 0.2 to 1 μm. More preferably it is. If it is less than 0.01 μm, sufficient adhesion and content resistance tend not to be obtained. On the other hand, if it exceeds 10 μm, it tends to be economically disadvantageous.

  The method for providing the adhesive layer in the present invention between the thermoplastic resin film and the sealant layer is not particularly limited, but the acid-modified polyolefin resin (A), polyvinyl alcohol (B), and the crosslinking agent (C) are described above. The coating material contained in the ratio is adjusted in advance, and the coating material is applied to the thermoplastic resin film to form a coating film (adhesive layer), and then the thermoplastic resin film and the sealant are passed through the adhesive layer. The method of laminating resin is mentioned, and this method is preferable from the viewpoint of exhibiting the effects of the present invention at low cost.

  As the coating material, the use of an aqueous dispersion in which the acid-modified polyolefin resin (A), the polyvinyl alcohol (B), and the crosslinking agent (C) are dispersed and dissolved in an aqueous medium makes it easy to obtain a preferable thickness of the adhesive layer. It is preferable because the effects of the present invention can be sufficiently exhibited. Here, the aqueous medium in the aqueous dispersion is a medium composed of water or a liquid containing water, and may contain a neutralizing agent that contributes to stabilization of the dispersion, a water-soluble organic solvent, or the like.

  The method for producing the aqueous dispersion is not particularly limited, but an aqueous dispersion of acid-modified polyolefin resin (A), an aqueous solution of polyvinyl alcohol (B), an aqueous solution of a crosslinking agent (C) or an aqueous dispersion is prepared individually. Then, a method of mixing each of them so that the composition ratio of (A), (B), (C) becomes a ratio specified in the present invention can be employed.

  The number average particle size of the dispersed particles in the aqueous dispersion is preferably 1000 nm or less, more preferably 10 to 500 nm, particularly preferably 30 to 300 nm, and further preferably 50 to 200 nm. When the number average particle diameter exceeds 1000 nm, the storage stability of the aqueous dispersion tends to decrease, and the effect of the present invention may decrease.

  As solid content concentration (nonvolatile component density | concentration) in an aqueous dispersion, it is preferable that it is the range of 1-50 mass% with respect to the whole aqueous dispersion.

  In the aqueous dispersion in the present invention, in addition to the acid-modified polyolefin resin (A), the polyvinyl alcohol (B) and the cross-linking agent (C), as long as the effects of the present invention are not impaired depending on the purpose of use in each application, Various additives can be added. Examples of the additive include resins other than (A), (B), and (C) (hereinafter referred to as “other resins”), inorganic fine particles, and the like.

  Specific examples of other resins include polyvinyl acetate, polyvinyl chloride, acrylic resin, acrylic silicon resin, ethylene-vinyl acetate copolymer, vinyl acetate-acrylic copolymer, ethylene-aminoacrylamide copolymer, ethylene- Amino acrylate copolymer, polyvinylidene chloride, styrene-maleic acid resin, styrene-aminoalkylmaleimide copolymer, styrene-butadiene resin, styrene elastomer, butadiene resin, acrylonitrile-butadiene resin, poly (meth) acrylonitrile resin, ( (Meth) acrylamide resin, chlorinated polyethylene resin, chlorinated polypropylene resin, polyester resin, modified nylon resin, polyurethane resin, phenol resin, silicone resin, epoxy resin, fluorine-containing resin, polyethylene resin , And a UV-curable resin. These can be used alone or in admixture of two or more. Among these, acrylic resin, polyurethane resin, and polyester resin are preferable from the viewpoint of further improving adhesiveness. When these resins are added, it is preferable to use those in which an aqueous dispersion or an aqueous solution is used.

  The addition amount of the other resin is preferably 0.1 to 300 parts by mass with respect to 100 parts by mass of the total amount of the acid-modified polyolefin resin (A), polyvinyl alcohol (B), and crosslinking agent (C), The amount is more preferably 3 to 200 parts by mass, and particularly preferably 5 to 100 parts by mass.

  On the other hand, as inorganic fine particles, for example, metal fine particles and metal oxides such as magnesium oxide, tin oxide, titanium oxide, calcium carbonate, silica, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, magnesium carbonate, calcium sulfate, Examples thereof include inorganic particles such as mica, talc, pseudoboehmite, alumina, aluminum silicate, calcium silicate, magnesium silicate, zirconium oxide, zirconium hydroxide, cerium oxide, lanthanum oxide, and yttrium oxide. These may be used alone or in combination of two or more.

  The average particle diameter of the inorganic fine particles is preferably 0.0005 to 100 μm, more preferably 0.005 to 10 μm from the viewpoint of dispersion stability of the aqueous dispersion.

  Furthermore, the aqueous dispersion in the present invention includes a leveling agent, an antifoaming agent, an anti-waxing agent, a pigment dispersant, an ultraviolet absorber, a catalyst, a photocatalyst, a UV curing agent, a wetting agent, and a penetrating agent as necessary. , Softeners, thickeners, dispersants, water repellents, antistatic agents, anti-aging agents, vulcanization accelerators, silane coupling agents, and other chemicals, pigments or dyes, carbon black, carbon nanotubes, glass fibers, etc. May be added. These may be used alone or in combination of two or more.

  The adhesive layer in the present invention is preferably a coating film obtained by applying an aqueous dispersion containing (A), (B), (C) and an aqueous medium to a thermoplastic resin film. In detail, after apply | coating an aqueous dispersion to at least one surface of a plastic resin film, a coating film can be formed by vaporizing a part or all of the aqueous medium in the apply | coated aqueous dispersion by drying.

  As a method for applying and drying the aqueous dispersion, known methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. By coating the aqueous dispersion uniformly on the surface of the thermoplastic resin film, setting it at around room temperature as necessary, and then subjecting it to a drying treatment or a heat treatment for drying, a part or all of the aqueous medium By vaporizing, a uniform coating film, that is, an adhesive layer can be formed in close contact with the surface of the thermoplastic resin film. Although a drying temperature is not specifically limited, it can dry favorably in the range of 40-150 degreeC. At the time of drying, it is preferable to vaporize all of the aqueous medium from the viewpoint of improving adhesiveness and content resistance.

  In addition, another layer or the like as will be described later is laminated in advance on either side of the thermoplastic resin film, and then the aqueous dispersion is applied and dried on at least a part of the other side. A layer may be formed.

  Next, conventionally known sealant resins can be used as the sealant layer in the present invention. For example, polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (L-LDPE) and high density polyethylene (HDPE), acid-modified polyethylene, polypropylene, acid-modified polypropylene, copolymerized polypropylene, ethylene-vinyl acetate copolymer And polyolefin resins such as ethylene- (meth) acrylic acid ester copolymers, ethylene- (meth) acrylic acid copolymers, and ionomers. Among them, polyethylene resins are preferable in terms of low-temperature sealing properties, and are inexpensive. Because of this, polyethylene is particularly preferred. Although it does not specifically limit as thickness of a sealant layer, The range of 10-60 micrometers is preferable and the range of 15-40 micrometers is more preferable in consideration of the workability, heat-sealing property, etc. of a laminated body. Further, by providing the sealant layer with irregularities of about 5 to 20 μm, it is possible to impart slipperiness to the sealant layer and tearability to the packaging material.

  As a method of providing the sealant layer, a method of laminating the above-mentioned sealant resin composed of the above-mentioned sealant resin to the adhesive layer provided on the thermoplastic resin film by heat (dry laminating method), or providing on the thermoplastic resin film Examples include a method of extruding a melted sealant resin to the obtained adhesive layer and then bonding it by cooling and solidifying (extruding lamination method). Among these, it is preferable to employ an extrusion laminating method from the viewpoint of performance such as adhesiveness and content resistance and cost. The melt sealant resin temperature when the extrusion laminating method is adopted is preferably in the range of 200 to 400 ° C, more preferably in the range of 250 to 350 ° C, and more preferably in the range of 280 to 330 from the viewpoint of improving adhesiveness and content resistance. A range of ° C is more preferred. In addition, the melt sealant resin at this time may be subjected to various surface treatments such as ozone treatment from the viewpoint of improving adhesiveness, content resistance, or line speed.

  Furthermore, in order to further improve performances such as adhesiveness and content resistance, the obtained laminate for packaging material may be subjected to an aging treatment. The aging treatment may be performed at a temperature of room temperature to about 60 ° C. for 12 to 200 hours.

  The packaging material of the present invention comprises a laminate in which a thermoplastic resin film, an adhesive layer and a sealant layer are laminated at least in this order. Usually, the thermoplastic resin film is on the outside and the sealant layer is on the inside (content side). Used, but not limited to this, the physical properties required for packaging materials (rigidity, impact resistance, durability, etc.), applications, and performance (easy tearing, handcut, pin resistance) Depending on the hole property, printability, transparency, concealment property, design property, etc.), another layer may be appropriately laminated and used as a laminate having various layer structures. For example, another layer such as a resin film, synthetic paper, paper, non-woven fabric, metal foil, vapor deposition layer, and printing layer may be laminated on the outside of the thermoplastic resin film, and these other layers are laminated alone. Alternatively, a plurality of layers may be stacked. Further, as another layer, a layer having the same composition as the above-described thermoplastic resin film, adhesive layer, and sealant layer is further provided as a second thermoplastic resin film, second adhesive layer, and second sealant layer. It doesn't matter.

  As the layer structure of the laminate, for example, a layer structure suitable for a paper container such as a second sealant layer / paper layer / barrier layer / thermoplastic resin film / adhesive layer / sealant layer, a paper cup, etc., or a second thermoplastic Resin film / barrier layer / thermoplastic resin film / adhesive layer / sealant layer, paper layer / barrier layer / thermoplastic resin film / adhesive layer / heat seal layer, second thermoplastic resin film / paper layer / barrier layer / heat Layer structure suitable for general packaging materials such as plastic resin film / adhesive layer / heat seal layer, lid materials, refill containers, etc. Furthermore, second sealant layer / barrier layer / thermoplastic resin film / adhesive layer / heat A layer structure suitable for a tube container such as a seal layer is exemplified. These laminates may be provided with a print layer, a top coat layer, or the like as necessary. Moreover, when laminating | stacking another layer, well-known adhesives, such as the two-component mixed type adhesive agent which mixed the main ingredient which has a hydroxyl group or a carboxyl group, and an isocyanate compound, for example can be used.

  Any material can be applied to the barrier layer used as another layer as long as it is a material capable of blocking liquid or gas. Specifically, in addition to soft metal foils such as aluminum foil, vapor deposition layers such as aluminum vapor deposition, silica vapor deposition, alumina vapor deposition, and silica alumina binary vapor deposition, and further vinylidene chloride resin, modified polyvinyl alcohol, ethylene vinyl alcohol co-polymerization An organic barrier layer made of coalescence, MXD nylon or the like can be used.

  When applying a vapor deposition layer as a barrier layer, it is convenient to use a commercially available vapor deposition film. As a film having such a vapor deposition layer, for example, “IB Series” manufactured by Dai Nippon Printing Co., Ltd., “GL, GX Series” manufactured by Toppan Printing Co., Ltd., “Barrier Rocks” manufactured by Toray Film Processing Co., Ltd., VM-PET YM-CPP, VM-OPP, “Tech Barrier” manufactured by Mitsubishi Plastics, “Metaline” manufactured by Tosero Co., Ltd., “MOS” “Tetrait” manufactured by Oike Kogyo Co., “Bibrite”, and the like can be used. In addition, you may provide a protective coat layer on a vapor deposition layer as needed.

  Further, when an organic barrier layer is applied as the barrier layer, it is easy to use a film having an organic barrier layer. In this case, as the film, a film in which a coating material containing a resin having a barrier property is applied, or a film in which a resin having a barrier property is laminated on the film by a co-extrusion method may be used. It is convenient and preferable to use a film having a layer. As a film having such an organic barrier layer, Kuraray's `` Clarista '', `` Eval '', Kureha Chemical Industry's `` Besera '', Mitsubishi Plastics' `` Super Neil '', Kojin's `` "Co-Barrier", "Savix (registered trademark)", "Embron M", "Embron E", "Emblem DC", "Emblet DC", "NV", manufactured by Unitika, "K-OP" manufactured by Tosero, Examples thereof include “A-OP” and “Seneci” manufactured by Daicel Corporation.

  In the present invention, from the viewpoint of barrier properties, a vapor deposition layer such as aluminum, silica, and alumina is generally suitable as the barrier layer in addition to an aluminum foil, and from the viewpoint of being particularly inexpensive, from aluminum such as an aluminum foil and an aluminum vapor deposition layer. A constructed barrier layer is preferred. Although it does not specifically limit as thickness of a barrier layer, For example, in the case of aluminum foil, 3-50 micrometers is preferable from an economical point.

The specific barrier property of the barrier layer is preferably about 100 g / m ² · day as the water vapor permeability, although it varies somewhat depending on the contents to be packaged and the storage period. (40 ° C., 90% RH) or less is preferred, 20 g / m ² · day or less is more preferred, 10 g / m ² · day or less is more preferred, and 1 g / m ² · day or less is particularly preferred. The oxygen permeability is preferably 100 ml / m ² · day · MPa (20 ° C., 90% RH) or less, more preferably 20 ml / m ² · day · MPa or less, and even more preferably 10 ml / m ² · day · MPa or less. 1 ml / m ² · day · MPa or less is particularly preferable.

  In addition, the above-mentioned another layer may contain a known additive or stabilizer, such as an antistatic agent, an easy-adhesion coating agent, a plasticizer, a lubricant, an antioxidant, etc., and is laminated with other materials. In order to improve the adhesion in the case of performing the treatment, the surface may be subjected to corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment or the like as pretreatment.

  The thickness of the other layer may be appropriately determined in consideration of suitability as a packaging material, workability when laminating, and the like, and is not particularly limited, but is practically in the range of 1 to 300 μm. Depending on the case, one having a thickness of 300 μm or more may be used.

  The laminate for packaging material of the present invention can be processed into various forms of packaging material by various processing methods, particularly heat sealing processing (processing for heat sealing via a heat sealing layer). Packaging materials include three-sided seal bags, four-sided seal bags, gusseted packaging bags, pillow packaging bags, gable top-type bottomed containers, tetra-classic, bruck types, tube containers, paper cups (for body and bottom) Each blank plate is produced, and the blank plate is formed into a cylindrical barrel portion using a cup molding machine, and the bottom portion is formed at one open end of the barrel portion and thermally bonded, etc.) And various forms such as a lid. Furthermore, a chuck made of polyethylene resin or polypropylene resin can be provided on the innermost sealant layer to form a packaging bag with a chuck. The laminate for packaging material of the present invention is also suitable for deep drawing.

  When the laminate for packaging material of the present invention is heat-sealed as described above to form a packaging material, wrinkles generated in the part that is not heat-sealed from the boundary line between the heat-sealed part and the part that is not heat-sealed ( In the present invention, it may be expressed as “wrinkles generated at the heat seal boundary portion” or the like, and it is excellent in appearance when used as a packaging material. Further, since the adhesive layer to be used has little adsorption of the contents, it is possible to suppress the odor transfer and coloring of the contents to the packaging material and to preserve the contents satisfactorily for a long period of time.

  Since the packaging material of the present invention has good content resistance to various contents, it is particularly suitable as a packaging material for wrapping volatile contents or strongly irritating contents. Especially, it is most suitable as a packaging material for products having fragrance components, spice components, and medicinal components. Specifically, alcohol (for example, high concentration alcohol of 50% by mass or more), alcoholic beverage, antioxidant, sulfite, fragrance, fragrance, bathing agent (liquid type, powder type), spice (clove, chili), Poultices, patches, pharmaceuticals, battery electrolytes, toiletries, surfactants, shampoos, rinses, detergents, car cleaners, perms, insecticides, insecticides, disinfectants, deodorants, hair restorers, vinegar , Toothpaste, cosmetics, developer, hair dye, toothpaste, mustard, vinegar, oil, curry, powdered kimchi, Tabasco (registered trademark, spice made from red pepper), limonene, toluene, xylene, acetic acid, Suitable for packaging materials containing basic substances and acidic substances.

  The laminate for packaging material of the present invention has excellent interlayer adhesion between the thermoplastic resin film and the sealant layer, and the required interlayer adhesion strength varies somewhat depending on the purpose of use and application, but generally has a width of 15 mm. The peel strength when the T-type peel is performed at a rate of 200 mm / min between the thermoplastic resin film and the sealant layer of the laminate cut into a thickness of 1.0 N / 15 mm or more is preferable, and 3.0 N / It is more preferably 15 mm or more, further preferably 5.0 N / 15 mm or more, particularly preferably 7.0 N / 15 mm or more, and most preferably non-peelable. Note that “non-peelable” refers to an embodiment in which the interlayer adhesive strength is too strong and the interface between the thermoplastic resin film and the sealant layer cannot be peeled at all. Specifically, when a trigger necessary for measurement cannot be provided, or even when a trigger can be provided, the laminate may be cut or stretched during measurement. If so, the interlayer adhesion strength is estimated to exceed 10 N / 15 mm.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

  Various characteristics were measured or evaluated by the following methods.

1. Characteristics of aqueous dispersion (1) Composition of acid-modified polyolefin resin (A)
^It calculated | required from the <1> H-NMR analyzer (the JEOL company make, ECA500, 500MHz). Tetrachloroethane (d ₂ ) was used as a solvent and measurement was performed at 120 ° C.
(2) Melt flow rate (MFR) of acid-modified polyolefin resin (A)
According to the method described in JIS K7210: 1999, the measurement was performed at 190 ° C. under a load of 2160 g.
(3) Saponification degree and average polymerization degree of polyvinyl alcohol (B) Measured according to the method described in JIS K6726: 1994.
(4) Number average particle diameter of dispersed particles of aqueous dispersion The particle diameter was determined using a Microtrac particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., UPA150, MODEL No. 9340, dynamic light scattering method). The refractive index of the resin used for particle diameter calculation was 1.50.
(5) Dispersion stability when mixed with water-insoluble solvents 20 g of aqueous dispersion and 0.5 g of toluene (water-insoluble solvent) are placed in a transparent glass bottle with an internal volume of 30 ml, and the glass bottle is closed and shaken vigorously. The dispersion and toluene were mixed. After mixing, the state of the aqueous dispersion in the bottle was visually evaluated with the following indices.
○: No aggregate Δ: Slightly aggregate x: Large amount of aggregate (6) Adsorption of content components The aqueous dispersion is dried on a polytetrafluoroethylene sheet at 120 ° C for 5 hours. Thus, a coating film having a thickness of 100 to 120 μm (a coating film having the same composition as the adhesive layer) was formed. Next, the coating film is peeled off from the polytetrafluoroethylene sheet and cut out so that the coating film has a mass of 0.3 g. Then, the coating film is put into a 100 ml glass container containing 20 g of limonene, and the container is sealed. Held at 0C. Limonene and the adhesive layer were separated from each other with a stainless mesh so as not to be in direct contact. After exposure to limonene gas at 50 ° C. for 5 days, the mass of the coating film was measured, and the adsorption rate was calculated by the following formula (1) (the smaller the adsorption rate, the lower the adsorptivity).
Adsorption rate (%) = [film mass after exposure (g) −0.3 (g)] ÷ 0.3 (g) × 100

2. Characteristics of the packaging material (1) Wrinkles generated at the heat seal boundary part In the packaging material, in the range of 50 mm boundary line between the heat seal part and the non-heat seal part, The number of wrinkles generated was visually counted.
(2) Adhesive strength (before content resistance test)
A test piece having a width of 15 mm and a length of 80 mm is cut out from the laminate for packaging material, and a thermoplastic resin film is formed from the end of the test piece by a T-peel method using a tensile tester (precision universal material tester type 2020 manufactured by Intesco). The strength required to peel off the sealant layer was measured. The measurement was performed in an atmosphere of 20 ° C. and 65% RH at a tensile speed of 200 mm / min.
(3) Content-resistant test Two 10 mm square test pieces are cut out from the laminate for packaging material, the sealant layer surfaces of the two test pieces are faced to each other and stacked so as not to be displaced, and the four test pieces are The ends of the three sides were heat sealed with a width of 5 mm to obtain a packaging material. Next, 10 g of toluene was added to the obtained packaging material as a content, and one side that was not sealed was heat-sealed with a seal width of 5 mm to obtain a packaging material in which toluene was enclosed. Thereafter, the packaging material was stored at 50 ° C. for 2 weeks in this state. After storage, the packaging material was opened, and the adhesive strength of the test piece was measured in the same manner as in (2) above.

Production Example 1 [Production of aqueous dispersion of acid-modified polyolefin resin (A)]
First, ethylene-ethyl acrylate-maleic anhydride copolymer [ethylene / ethyl acrylate / maleic anhydride = 83 / 14.5 / 2.5 (mass ratio), random copolymer, MFR = 4 g / 10 min, Hereinafter, “abbreviated as“ PE-M ”] was prepared.

  Next, 60.0 g of PE-M, 90.0 g of isopropanol, 3.0 g of triethylamine, and 147.0 g of distilled water were added using a stirrer equipped with a heat-resistant 1-liter glass container equipped with a heater. When charged in a glass container and stirred at a rotation speed of the stirring blade of 300 rpm, no precipitation of resin particles was observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 to 145 ° C. and further stirred for 30 minutes. Thereafter, the glass container is placed in a water bath, cooled to room temperature (about 25 ° C.) with stirring at a rotational speed of 300 rpm, and then filtered under pressure through a 300-mesh stainless steel filter (wire diameter 0.035 mm, plain weave) 2 MPa) to obtain a milky white uniform aqueous dispersion of PE-M. The solid content concentration of the obtained PE-M aqueous dispersion was 20% by mass.

Production Example 2 [Production of polyvinyl alcohol (B) aqueous solution PVA1-3]
As polyvinyl alcohol (B), manufactured by Nippon Vinegar Poval, VC-10 (hereinafter referred to as “VC-10”), JF-03 (hereinafter referred to as “JF-03”), JL-25E (hereinafter referred to as “PVC”). 8 "mass% polyvinyl alcohol aqueous solution was obtained by adding water, heating and stirring using" JL-25E ". The aqueous solution of VC-10 is “PVA1”, the aqueous solution of JF-03 is “PVA2”, and the aqueous solution of JL-25E is “PVA3”.

Moreover, the saponification degree and average polymerization degree of the polyvinyl alcohol used for the raw material are as follows.
VC-10: polymerization degree 1000, saponification degree 99.5 mol%
JF-03: polymerization degree 300, saponification degree 99.0 mol%
JL-25E: polymerization degree 2500, saponification degree 79.0 mol%

<Example 1>
First, an aqueous dispersion of PE-M as an aqueous dispersion of the acid-modified polyolefin resin (A), PVA1 as an aqueous solution of polyvinyl alcohol (B), and an aqueous solution of a polyvalent oxazoline compound as an aqueous solution of a crosslinking agent (C) [Japan Catalyst Co., Ltd., Epocros WS-700 (registered trademark), polyvalent oxazoline compound concentration of 25 mass%, number average molecular weight of about 20000, hereinafter abbreviated as “WS-700”] were prepared. Next, with respect to 100 parts by mass of the acid-modified polyolefin resin (A) in the aqueous dispersion of PE-M, the aqueous dispersion of PE-M is adjusted so that the polyvinyl alcohol (B) is 0.1 part by mass. PVA1 was mixed with stirring. And so that a crosslinking agent (C) may be 5 mass parts with respect to 100 mass parts (A + B) of the total amount of acid-modified polyolefin resin (A) and polyvinyl alcohol (B) contained in the obtained liquid mixture. The above mixed solution and WS-700 were mixed with stirring to prepare an aqueous dispersion containing (A), (B), (C) and an aqueous medium.

  Next, the obtained aqueous dispersion is applied to the corona-treated surface of a biaxially stretched PET film (Unitika, Emblet PET-25, thickness 25 μm, corona-treated product) which is a thermoplastic resin film. It was applied so that the thickness of the coating film was 0.3 μm, and dried at 100 ° C. for 2 minutes to form an adhesive layer. Next, using a laminating apparatus equipped with an extruder, a sealant resin LDPE (Sumitomo Chemical, Sumikasen L211) is melt-extruded on the surface of the adhesive layer at a die temperature of 320 ° C. to form a sealant layer made of 40 μm LDPE. As a result, a laminate for packaging material comprising a thermoplastic resin film, an adhesive layer and a sealant layer was obtained.

<Examples 2 to 9, Comparative Examples 2 and 4>
Except for changing the contents of (A), (B), and (C) in the aqueous dispersion as shown in Table 1, the same operation as in Example 1 was performed to obtain a laminate for packaging material. .

<Examples 10 and 11>
A laminate for packaging material is obtained by performing the same operation as in Example 3 except that PVA2 (Example 10) and PVA3 (Example 11) are used as an aqueous solution of polyvinyl alcohol (B) instead of PVA1. It was.

<Example 12>
As an aqueous solution of the crosslinking agent (C), an aqueous solution of a polyvalent carbodiimide compound instead of WS-700 [manufactured by Nisshinbo Chemical Co., Ltd., Carbodilite V-02-L2 (registered trademark), a concentration of polyvalent carbodiimide compound of 40% by mass, hereinafter, “V Except for using abbreviated as “-02-L2”], the same operation as in Example 3 was performed to obtain a laminate for packaging material.

<Example 13>
The same operation as in Example 3 was performed except that a biaxially stretched Ny6 film (manufactured by Unitika, emblem, thickness 15 μm, corona-treated product) was used as the thermoplastic resin film instead of the biaxially stretched PET film. A laminate for packaging material was obtained.

<Comparative Example 1>
An aqueous dispersion of PE-M and WS-700 are added so that the crosslinking agent (C) is 5 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A) in the aqueous dispersion of PE-M. By stirring and mixing, an aqueous dispersion containing (A), (C) and an aqueous medium was prepared. That is, an aqueous dispersion containing no polyvinyl alcohol (B) was prepared. And after that, except using this aqueous dispersion, the same operation as in Example 1 was performed to obtain a laminate for packaging material.

<Comparative Example 3>
An aqueous dispersion of PE-M and PVA1 are added so that polyvinyl alcohol (B) is 0.1 part by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A) in the aqueous dispersion of PE-M. By stirring and mixing, an aqueous dispersion containing (A), (B) and an aqueous medium was prepared. That is, an aqueous dispersion containing no crosslinking agent (C) was prepared. And after that, except using this aqueous dispersion, the same operation as in Example 1 was performed to obtain a laminate for packaging material.

<Comparative Example 5>
As the thermoplastic resin film, the same operation as in Comparative Example 1 was performed except that a biaxially stretched Ny6 film (manufactured by Unitika, emblem, thickness 15 μm, corona-treated product) was used instead of the biaxially stretched PET film. A laminate for packaging material was obtained.

  Table 1 shows the evaluation results of the aqueous dispersions used in Examples 1 to 13 and Comparative Examples 1 to 5 and the packaging materials obtained in each example.

  The aqueous dispersions used in Examples 1 to 13 were excellent in dispersion stability when mixed with water-insoluble solvents. Therefore, when forming an adhesive layer using various coaters, it can be said that fine agglomerates are not substantially generated in the aqueous dispersion even if some water-insoluble solvent is mixed during the coating material replacement operation. It can be said that a uniform adhesive layer can be formed at the manufacturing site.

  Moreover, in Examples 1-13, the coating film was hard to adsorb | suck a content component. Limonene was used as the content for evaluating the adsorptive properties of the contents, but limonene is a highly diffusive substance and it is difficult to adsorb the limonene. Is done. Therefore, it can be said that the packaging material of this invention is excellent in the adsorption | suction suppression effect regardless of the kind of content from this point.

  And the packaging material of this invention was equipped with the contact bonding layer derived from the said aqueous dispersion, it was hard to generate | occur | produce a wrinkle in a heat seal boundary part, and it was excellent also in adhesiveness and content resistance performance.

  On the other hand, the packaging materials according to Comparative Examples 1 to 5 did not have both the wrinkle suppressing effect and the content resistance performance.

Claims (7)

  A laminated body in which a thermoplastic resin film, an adhesive layer and a sealant layer are laminated at least in this order, and the adhesive layer contains an acid-modified polyolefin resin (A), polyvinyl alcohol (B) and a crosslinking agent (C). The polyvinyl alcohol (B) is contained in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A), and the total amount of (A) and (B) is 100 parts by mass (A + B). On the other hand, the laminated body for packaging materials characterized by containing 0.1-30 mass parts of crosslinking agents (C).   The adhesive layer is a coating film obtained from an aqueous dispersion containing an acid-modified polyolefin resin (A), polyvinyl alcohol (B), a crosslinking agent (C) and an aqueous medium. Laminate for packaging materials.   The laminate for packaging materials according to claim 1 or 2, wherein the thermoplastic resin film is a polyester resin film or a polyamide resin film.   The laminate for a packaging material according to any one of claims 1 to 3, wherein the crosslinking agent (C) is an oxazoline-based crosslinking agent and / or a carbodiimide-based crosslinking agent.   The packaging material obtained by heat-sealing the laminated body for packaging materials in any one of Claims 1-4.   A method for producing a laminate in which a melted sealant resin is laminated by extrusion lamination on a thermoplastic resin film via an adhesive layer, wherein the adhesive layer is an acid-modified polyolefin resin (A), polyvinyl alcohol (B) And the crosslinking agent (C), the polyvinyl alcohol (B) is contained in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin (A), and (A) and (B). The manufacturing method of the laminated body for packaging materials characterized by containing 0.1-30 mass parts of crosslinking agents (C) with respect to 100 mass parts (A + B) of the total amount.   The adhesive layer is a coating film obtained from an aqueous dispersion containing an acid-modified polyolefin resin (A), polyvinyl alcohol (B), a crosslinking agent (C) and an aqueous medium. A method for producing a laminate for packaging material.