JP6318656B2 - Packaging materials - Google Patents

Description

  The present invention relates to a packaging material in which at least an adhesive layer and a sealant layer are provided in this order on a base film having a multilayer structure.

  Conventionally, as a packaging material for packaging foods, pharmaceuticals, and the like, for example, a laminate in which layers are laminated such as a paper layer / polyethylene layer / aluminum foil layer / polyester layer / sealant layer has been widely used. The polyester layer and sealant layer of this laminate are usually laminated by applying an anchor coating agent such as a two-component curable polyurethane to the polyester layer consisting of a polyester film, and then extruding and sealing the sealant layer. This is done by attaching a sealant layer through an extruded polyethylene resin.

  Such a laminate has an appropriate laminate strength, gas barrier properties, and the like, and is widely used as a packaging material for packaging foods and pharmaceuticals.

  However, many of the contents packaged by the packaging material contain an alkaline substance, a fragrance, a surfactant, a high-boiling organic solvent, etc., and when these contents are packaged, an adhesive that constitutes an adhesive layer In some cases, the laminate strength of the laminate may be reduced, or peeling may occur.

  In order to cope with this situation, various improvements have been made to the adhesive used for laminating, improving the resistance to highly alkaline contents, and further improving the adhesion to various plastic films. Various agents and the like have been proposed (see, for example, Patent Document 1).

  However, it is necessary to use a laminate having the above-described structure containing a volatile component or a strong osmotic component, such as a poultice or a bath preparation, or a laminate obtained by using the anchor coat agent as a packaging material or a material. When used as a package, the laminate strength between the polyester film and the sealant layer decreases with time due to the strong penetration of volatile substances, resulting in a problem of delamination.

  Patent Document 2 discloses a technique for solving such a problem. That is, in Patent Document 2, a single-layer film selected from a polyester film, a nylon film, and a polypropylene film is used as the base film in order to prevent a decrease in the laminate strength between the base film and the sealant layer. And the technique which adhere | attaches this base film and a sealant layer using the contact bonding layer which consists of a bifunctional or trifunctional isocyanate compound is proposed.

JP-A-10-130615 JP 2005-335374 A

  However, even when an isocyanate compound is used for the adhesive layer, if the base film has a multilayer structure (for example, a multilayer structure consisting of “paper layer / polyethylene layer / aluminum foil layer”), a volatile component In addition, the strong penetrating component penetrates into the base film and invades the adhesive layer between the layers constituting the base film, so that the laminate strength between the layers is lowered. .

  Therefore, an object of the present invention is a packaging material formed by laminating a base film, an adhesive layer, and a sealant layer in this order, and also when a content containing a volatile component or a strong permeable component is packaged. An object of the present invention is to provide a packaging material in which a decrease in laminate strength of each layer is suppressed.

  The present invention relates to a packaging material comprising a base film, an adhesive layer, and a sealant layer laminated in this order, the adhesive layer comprising a bifunctional or higher functional isocyanate compound, wherein the base film is an intermediate made of polyamide. Including an intermediate film in which a primer layer, an inorganic vapor deposition layer, and a gas barrier coat layer are laminated in this order on a film substrate, the intermediate film substrate is bonded to the sealant layer via an adhesive layer, and the primer layer is an oxazoline group It is formed by a resin mixture containing a water-soluble polymer, a water-based acrylic resin, a water-based urethane resin and / or a water-based polyester resin.

  According to the present invention, in a packaging material configured by laminating a base film, an adhesive layer, and a sealant layer in this order, even when contents containing a volatile component or a strong permeable component are packaged, the lamination of each layer A decrease in strength can be suppressed.

Sectional drawing of the packaging material which concerns on the 1st Embodiment of this invention Sectional drawing of the packaging material which concerns on the 2nd Embodiment of this invention. Sectional drawing of the packaging material which concerns on the 3rd Embodiment of this invention Sectional drawing of the packaging material which concerns on the 4th Embodiment of this invention Sectional drawing of the packaging material which concerns on Example 1 of this invention Sectional drawing of the packaging material which concerns on Example 2 of this invention Sectional drawing of the packaging material which concerns on Example 3 of this invention Sectional drawing of the packaging material which concerns on the comparative example 1 Sectional drawing of the packaging material which concerns on the comparative example 2 Sectional drawing of the packaging material which concerns on the comparative example 3 Sectional drawing of the packaging material which concerns on Examples 4-6 of this invention Sectional drawing of the packaging material which concerns on the comparative examples 4 and 5 Sectional drawing of the packaging material which concerns on the comparative example 6

  Hereinafter, the packaging material according to each embodiment will be described with reference to the drawings. The packaging material according to each of the following embodiments is a sheet material having a multilayer structure, and is typically used in the form of a packaging bag. In the case of manufacturing a packaging bag using a packaging material, a sealant layer is used on the inner surface to heat seal each other to form a packaging bag. Therefore, in the following description, the side that accommodates the contents, that is, the sealant layer side is referred to as “inside”, and the opposite side is referred to as “outside”.

(First embodiment)
FIG. 1 is a cross-sectional view of a packaging material according to the first embodiment of the present invention.

  The packaging material according to the first embodiment is configured by laminating a base film, an adhesive layer 3 and a sealant layer 4 in this order. The base film has a multilayer structure formed by laminating an outer film 1 positioned on the outer side and an intermediate film 2 positioned on the inner side. The intermediate film 2 is configured by laminating a primer layer 22, an inorganic vapor deposition layer 23, and a gas barrier coat layer 24 in this order on an intermediate film substrate 21, and the gas barrier coat layer 24 is bonded to the adhesive layer 3. ing. As a result, the packaging material according to the first embodiment has an outer film 1, an intermediate film substrate 21, a primer layer 22, an inorganic vapor deposition layer 23, a gas barrier coat layer 24, an adhesive, in order from the outside, as shown in FIG. The layer 3 and the sealant layer 4 are laminated.

(Second Embodiment)
FIG. 2 is a cross-sectional view of a packaging material according to the second embodiment of the present invention.

  The packaging material according to the second embodiment further includes a resin layer 5 between the adhesive layer 3 and the sealant layer 4 in addition to the layer configuration of the packaging material according to the first embodiment.

Although it is desirable that the gas barrier coat layer 24 and the adhesive layer 3 are directly bonded, the adhesive layer 3 and the sealant layer 4 may be indirectly bonded via another layer therebetween. . For example, a film provided with the adhesive layer 3 on the gas barrier coat layer 24 and a sealant layer 4 formed into a sheet are separately prepared, and a resin such as polyethylene is melted between the two and extruded from an extruder. Both can be bonded via the extruded molten resin. In this case, it is desirable to surface-treat the sheet-like sealant layer 4 in advance. For example, corona treatment or ozone treatment. Also, it is desirable to extrude the resin to be melt extruded at such a high temperature that the surface is oxidized.
(Third embodiment)
FIG. 3 is a cross-sectional view of a packaging material according to the third embodiment of the present invention.

  The packaging material according to the third embodiment is an example in which a film having a multilayer structure is adopted as the outer film 1. In this example, the outer film 1 has a structure in which a stretched polyamide film 11, a printing ink layer 12, a dry laminating adhesive layer 1ad, and an aluminum foil 13 are laminated in order from the outside. Further, the outer film 1 and the intermediate film substrate 21 are bonded through an adhesive layer ad formed of an adhesive for dry lamination.

  Hereinafter, details of each layer of the packaging material according to the first to third embodiments will be described.

(Outer film)
The outer film 1 may be composed of a single layer as in the first and second embodiments, or a multilayer composed of a plurality of layers laminated as in the third embodiment. A film having a structure may be used.

  As the outer film 1 having a single layer structure, for example, a stretched plastic film can be suitably used. Examples thereof include a stretched polyester film such as a stretched polyamide film and a stretched polyethylene terephthalate film, and a stretched polypropylene film. It is also possible to use paper as the outer film 1.

  In addition to the stretched plastic film or paper described above, the outer film 1 having a multilayer structure desirably has a pattern layer or a gas barrier layer with printing ink in a part of the layer. A gas barrier layer interrupts | blocks oxygen gas and water vapor | steam, and improves the preservability of the content. Examples of such a gas barrier layer include a metal foil such as an aluminum foil or a vapor deposition film having an inorganic vapor deposition layer. When an aluminum foil layer is provided as a gas barrier layer, it can be applied to a packaging material and is suitable for packaging applications of contents containing components that deteriorate with light. Each layer which comprises the multilayer outer film 1 can be adhere | attached with the adhesive agent for dry lamination, for example. Moreover, it is also possible to laminate | stack through molten resin, such as polyethylene extruded from the extruder.

(Intermediate film substrate)
The intermediate film substrate 21 may also be composed of a single layer, or may have a multilayer structure configured by laminating a plurality of layers. A typical intermediate film substrate 21 is a plastic film composed of a single layer. Examples of such a representative intermediate film substrate 21 include a polyester film, a nylon film, a polypropylene film, a cyclic olefin resin film, and a copolymer resin film containing a cyclic olefin monomer. The resin film used for the intermediate film substrate 21 may be a stretched film or an unstretched film.

The outer film 1 and the intermediate film base material 21 can be laminated via an adhesive layer. As the adhesive layer, for example, an adhesive formed from an adhesive for dry lamination can be used. In addition, even if the outer film 1 and the intermediate film base material 21 are bonded with an adhesive for dry lamination in this way, and each layer of the outer film 1 having a multilayer structure is bonded with an adhesive for dry lamination, the inorganic vapor deposition layer Since both 23 and the gas barrier coat layer 24 prevent the penetration of volatile components and strongly permeable components, the deterioration of the laminate strength over time is suppressed.
(Primer layer)
Next, the primer layer 22 according to the present invention has a role to firmly adhere the intermediate film base material 21 and the inorganic vapor deposition layer 23. Any layer may be used as long as it fulfills this role. For example, a layer obtained by reaction-curing the following (a) to (c) can be preferably used.
(A) An acrylic polyol having a hydroxyl value of 5 to 200 (KOHmg / g).
(B) Isocyanate compound.
(C) A silane coupling agent that reacts with at least one of the hydroxyl group of the acrylic polyol (a) and the isocyanate group of the isocyanate compound (b).

  The functional group of the silane coupling agent in the primer layer 22 reacts with the hydroxyl group of the polyol or the isocyanate group of the isocyanate compound to form a covalent bond. This covalent bond makes it possible to form a strong primer layer 22. Moreover, the silanol group produced | generated by the hydrolysis of the alkoxy group or the alkoxy group exhibits the strong interaction with the metal in the inorganic vapor deposition layer 23, and the polar surface of the inorganic vapor deposition layer 23, and this interaction with the inorganic vapor deposition layer 23 is demonstrated. High adhesion is expressed. Thus, the primer layer 22 has a role of firmly fixing the inorganic vapor deposition layer 23 to the intermediate film base material 21.

  As the acrylic polyol, a polyol obtained by polymerizing an acrylic acid derivative monomer can be used. It is also possible to use polyols obtained by copolymerizing acrylic acid derivative monomers and other monomers. Examples of acrylic acid derivative monomers include ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate. Moreover, styrene can be illustrated as another monomer. In any case, the hydroxyl number needs to be 5 to 200 (KOH mg / g).

  Next, as the isocyanate compound, an aromatic isocyanate compound, an aliphatic isocyanate compound, or a polymer or derivative thereof can be used. Representative aromatic isocyanate compounds include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and xylene diisocyanate (XDI). Examples of the aliphatic isocyanate compound include hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI).

  Further, the blending ratio of the acrylic polyol and the isocyanate compound is not particularly limited, but if the isocyanate compound is too small, the curing may be poor, and conversely if it is too much, blocking or the like occurs and there is a problem in processing. . Therefore, the mixing ratio of the acrylic polyol and the insocyanate compound is preferably that the NCO group derived from the isocyanate compound is 50 times or less of the OH group derived from the acrylic polyol, and particularly preferably the NCO group and the OH group are equivalent. This is the case where it is blended. The mixing method may be any method.

  Next, the silane coupling agent needs to have a functional group that reacts with the hydroxyl group of the polyol or the isocyanate group of the isocyanate compound. Examples of such functional groups include isocyanate groups, mercapto groups, amino groups, epoxy groups, and hydroxyl groups. Examples of the silane coupling agent having an isocyanate group include γ-isocyanatopropyltriethoxysilane and γ-isocyanatopropyltrimethoxysilane. Examples of the silane coupling agent having a mercapto group include γ-mercaptopropyltriethoxysilane. Examples of the silane coupling agent having an amino group include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, γ-phenylaminopropyltriethoxysilane. Methoxysilane is mentioned. Examples of the silane coupling agent having an epoxy group include γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. The silane coupling agent having a hydroxyl group can be produced by adding alcohol or the like to the silane coupling agent. For example, a silane coupling agent having a hydroxyl group can be produced by adding alcohol or the like to vinyltrimethoxysilane. It is also possible to produce a silane coupling agent having a hydroxyl group by adding alcohol or the like to vinyltris (β-methoxyethoxy) silane.

  In addition, although a silane coupling agent generally has an alkoxyl group, what hydrolyzed this alkoxyl group may be used as a silane coupling agent. Moreover, what has a chloro group and an acetoxy group may be used instead of an alkoxyl group. All of these hydrolyze to produce silanol groups, and the silanol groups exert a strong interaction with the inorganic vapor deposition layer 23. Therefore, the silane coupling agent in the present invention contains these derivatives.

  The blending ratio of the acrylic polyol and the silane coupling agent is preferably such that the equivalent ratio of the hydroxyl group of the polyol and the isocyanate group of the isocyanate compound is in the range of 1/1000 to 1000/1.

  The primer layer 22 can be formed by dissolving the above-described acrylic polyol, isocyanate, and silane coupling agent in a solvent, applying the solution to the intermediate film substrate 21, drying by heating, and curing. As the solvent, esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as methyl ethyl ketone, and aromatic hydrocarbons such as toluene and xylene can be used.

(Inorganic vapor deposition layer)
Next, the inorganic vapor deposition layer 23 which concerns on this invention cooperates with the gas barrier coat layer 24, and prevents the penetration | invasion of the volatile component in a content, or a strong permeability component. Since the volatile component and the strong penetrating component are generally organic substances, the inorganic vapor deposition layer 23 needs to have a low affinity with the organic substance in order to prevent the penetration of the organic substance. Such an inorganic vapor deposition layer 23 can be composed of a compound of a metal element or a metalloid element. Examples of metal elements and metalloid elements include silicon, aluminum, titanium, zirconium, tin, and magnesium. Examples of the compound include oxides, nitrogen, fluorides, and the like. The inorganic vapor deposition layer 23 can be formed on the primer layer 22 by a vacuum process such as vacuum vapor deposition, sputtering, or plasma vapor deposition. The thickness of the inorganic vapor deposition layer 23 should just be 50-5000 angstrom.

(Gas barrier coat layer)
Next, as described above, the gas barrier coat layer 24 cooperates with the inorganic vapor deposition layer 23 to prevent the penetration of volatile components and strong permeable components in the contents. Further, the gas barrier coat layer 24 firmly bonds the inorganic vapor deposition layer 23 and the adhesive layer 3, and prevents a decrease in the laminate strength against the penetration of volatile components and strong permeable components in the contents. Also has a role to play.

As the gas barrier coating layer 24 having such technical significance, a film formed by applying the following coating solution and drying and curing it can be suitably used. That is, this coating solution contains at least one of the following (d) and (e) in addition to the water-soluble polymer.
(D) Metal alkoxide, silicon alkoxide, or a hydrolyzate thereof.
(E) Tin chloride

  In addition to these essential components, the coating solution may contain known additives such as isocyanate compounds, silane coupling agents, or dispersants, stabilizers, viscosity modifiers, and colorants.

  As a solvent for the coating solution, water or a mixed solvent of water and alcohol can be used. And by apply | coating this coating liquid and heat-drying, the component in a liquid chemically reacts and the firm film | membrane excellent in barrier properties, such as a volatile substance, is made. That is, when this coating liquid contains a metal alkoxide or a hydrolyzate thereof, the metal alkoxide (or a hydrolyzate thereof) reacts with the water-soluble polymer to form a barrier film.

  Examples of the water-soluble polymer used in the coating solution include polyvinyl alcohol (PVA), polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, acrylic resin, and sodium alginate. PVA here is generally obtained by saponifying polyvinyl acetate, from so-called partially saponified PVA in which several tens percent of acetic acid groups remain to completely saponified PVA in which only several percent of acetic acid groups remain. There is no particular limitation.

A metal alkoxide is a compound represented by the general formula M (OR) n, where M is a metal, OR is an alkoxy group, and n is the coordination number of an alkoxy group. It is preferable that M is selected from the group consisting of Ti, Al and Zr, and R is selected from a methyl group and an ethyl group. Silicon alkoxide is a compound represented by the general formula Si (OR) n. In particular, when tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ] or the like is used, the hydrolysis product of the alkoxide is water-based. It is preferable because it exists relatively stably in a solvent.

  This coating solution can be applied by a method such as a roll coating method, a screen printing method, a gravure coating method, or a spray coating method. The thickness of the coating may be such that the thickness after drying is in the range of 0.01 to 100 μm. After the application, the gas barrier coat layer 24 can be formed by heating and drying.

(Adhesive layer)
Next, the adhesive layer 3 is a layer having a role of firmly bonding the gas barrier coat layer 24 and the sealant layer 4. In addition, the adhesive layer 3 has a role of preventing a decrease in the laminate strength against the penetration of the volatile component and the strong permeable component in cooperation with the gas barrier coat layer 6 and the sealant layer 4. As described above, it is desirable that the gas barrier coat layer 24 and the adhesive layer 3 are directly bonded, but the adhesive layer 3 and the sealant layer 4 are indirectly connected via another layer (for example, the resin layer 5). It may be bonded.

  The adhesive layer 3 can be formed by using an adhesive composed of a bifunctional or higher functional isocyanate compound. Difunctional isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate and hydrogenated products thereof System monomers can be used. Further, as the trifunctional isocyanate compound, a derivative of the diisocyanate monomer is preferable. For example, an adduct type obtained by reacting these diisocyanate monomers with a trifunctional active hydrogen-containing compound such as trimethylolpropane or glycerol, a burette type reacted with water, and a trimer (isocyanurate) utilizing self-polymerization of isocyanate groups. ) Type trifunctional derivatives can be used. Of course, a tetrafunctional or higher polyfunctional derivative may be used.

  The adhesive layer 3 can be formed by first adjusting a coating liquid containing 0.05 to 5 wt% of an isocyanate compound in a solid content ratio and coating the coating liquid on the gas barrier coat layer 24. The adhesive layer 3 is preferably a thin layer. Specifically, the adhesive layer 3 may be provided so as to be a thin layer having a thickness of 1 μm or less when dried.

(Sealant layer)
Next, the sealant layer 4 includes a polyethylene resin, a polypropylene resin, an ethylene-α, β unsaturated carboxylic acid copolymer or an esterified product thereof or an ionic cross-linked product thereof, an acid anhydride-modified polyolefin, an epoxy compound-modified polyolefin, ethylene -A layer made of vinyl acetate copolymer or the like. Examples of the ethylene resin include high density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene, and ethylene-α olefin copolymer. Examples of polypropylene resins include homopropylene resins and propylene-α olefin copolymers. Examples of the ethylene-α, β unsaturated carboxylic acid copolymer include an ethylene-acrylic acid copolymer and an ethylene-methacrylic acid copolymer. Examples of the esterified product of the ethylene-α, β-unsaturated carboxylic acid copolymer include ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, and ethylene-ethyl methacrylate. Examples of the ion-crosslinked product of the ethylene-α, β unsaturated carboxylic acid copolymer include an ethylene-α, β unsaturated carboxylic acid copolymer in which the carboxylic acid sites are crosslinked with sodium ions and zinc ions. Examples of the acid anhydride-modified polyolefin include terpolymers such as ethylene-maleic anhydride graft copolymer and ethylene-ethyl acrylate-maleic anhydride. Examples of the epoxy compound-modified polyolefin include an ethylene-glycidyl methacrylate copolymer. Moreover, the blend of these resins may be sufficient, and what added various additives (Antioxidant, a tackifier, a filler, various fillers, etc.) may be used.

  The sealant layer 4 can be formed by extruding a resin constituting this from an extruder in a molten state and laminating the adhesive layer 3 on the adhesive layer 3. Moreover, it is also possible to laminate | stack on the contact bonding layer 3 indirectly through another layer (for example, resin layer 5) like 2nd Embodiment. As the resin layer 5, a resin having high affinity for the adhesive layer 3 and the sealant layer 4 can be used. For example, when the sealant layer 4 is a polyethylene resin or a copolymer resin of ethylene and another monomer, a polyethylene resin can be used as the resin layer 5. For example, by extruding at a high temperature of about 320 ° C. under the die to oxidize the surface, and in a molten state, the adhesive layer 3 and the sealant layer 4 are pressed against the oxidized surface to firmly bond them. Can do.

  As described above, in the first to third embodiments, as the intermediate film 2 positioned on the inner side of the base film, the primer layer 22, the inorganic vapor deposition layer 23, and the gas barrier coat layer are formed on the intermediate film base 21. A film in which 24 is laminated in this order is used, and the inorganic vapor-deposited layer 23 and the gas barrier coat layer 24 are positioned on the inner side of the intermediate film substrate 21, and the gas barrier coat layer 24 is bonded to the adhesive layer 3. By adopting such a laminated structure, both the inorganic vapor-deposited layer 23 and the gas barrier coat layer 24 prevent the penetration of volatile components and strong permeable components. Decline can be prevented.

  In the first to third embodiments, the gas barrier coat layer 24 and the sealant layer 4 are bonded by the adhesive layer 3 made of a bifunctional or trifunctional isocyanate compound. The gas barrier coat layer 24 is a material different from the base film (polyester film, nylon film, polypropylene film) described or suggested in Patent Document 2, and these base materials also in terms of chemical structure and function. Despite its poor similarity to films, it adheres firmly to an adhesive layer composed of a bifunctional or trifunctional isocyanate compound. And the adhesive layer 3 is hard to be eroded by the volatile component or the strong permeable component, and the decrease in the laminate strength is remarkably suppressed.

  Therefore, by adopting the laminated structure according to the first to third embodiments, it is possible to suppress a decrease in the laminate strength between the layers constituting the base film, and the laminate strength between the base film and the sealant layer 4. Can also be suppressed. Therefore, the packaging material which concerns on 1st-3rd embodiment is suitable as a packaging material of the content containing a volatile component and a strong permeability component. These technical effects will be described later based on the data of Examples 1 to 3.

(Fourth embodiment)
FIG. 4 is a cross-sectional view of a packaging material according to the fourth embodiment of the present invention. Hereinafter, the layer structure of the packaging material according to the fourth embodiment will be described with reference to FIG.

  The packaging material according to the fourth embodiment is configured by laminating a base film, an adhesive layer 3 and a sealant layer 4 in this order. The base film has a multilayer structure formed by laminating an outer film 1 positioned on the outer side and an intermediate film 2 positioned on the inner side (the sealant layer 4 side). Further, the intermediate film 2 is configured by laminating a primer layer 22, an inorganic vapor deposition layer 23, and a gas barrier coat layer 24 in this order on the intermediate film base 21, and the intermediate film base 21 adheres to the adhesive layer 3. Has been. As a result, the packaging material according to the fourth embodiment includes, as shown in FIG. 4, the outer film 1, the adhesive layer ad, the gas barrier coat layer 24, the inorganic vapor deposition layer 23, the primer layer 22, and the intermediate film in order from the outside. The substrate 21, the adhesive layer 3, and the sealant layer 4 are stacked.

(Outer film)
In the packaging material according to the fourth embodiment, a film having a multilayer structure is used as the outer film 1. In the example of FIG. 4, the outer film 1 has a structure in which an outer film base 14, a dry laminating adhesive layer 1 ad, and a gas barrier layer 13 are laminated in order from the outer side. Further, the outer film 1 and the intermediate film substrate 21 are bonded through an adhesive layer ad formed of an adhesive for dry lamination. As the outer film substrate 14, for example, a stretched polyamide film, a stretched polyester film, a stretched polypropylene film, paper, or the like can be used. Moreover, the gas barrier layer 13 can use metal foil, such as aluminum, and an inorganic oxide vapor deposition film.

  In the present embodiment, an example using the outer film 1 having a multilayer structure has been described. However, as described in the first and second embodiments, a film composed of a single layer is used for the outer film 1. Also good.

(Intermediate film substrate)
For the intermediate film substrate 21, a polyamide film made of nylon or other polyamide resin is used. This intermediate film substrate 21 may be a stretched film or an unstretched film. Since the polyamide film is excellent in adhesiveness with the isocyanate compound constituting the adhesive layer 3, even when the contents of the packaging container prepared using the packaging material contain a volatile component or a strong penetrating component, these The adhesion portion is less likely to be eroded by the components, and peeling between the intermediate film 2 and the sealant layer 4 can be suppressed.

(Primer layer)
The primer layer 22 is a layer having a role of firmly bonding the intermediate film substrate 21 and the inorganic vapor deposition layer 23. The primer layer 22 according to the present embodiment is formed by applying a resin mixture including the following components (f) to (h) on the intermediate film base material 21 and curing it.
(F) Oxazoline group-containing water-soluble polymer (g) Water-based acrylic resin (h) Water-based urethane resin and / or water-based polyester resin

(Inorganic vapor deposition layer)
The inorganic vapor deposition layer 23 cooperates with the gas barrier coat layer 24 to prevent the penetration of volatile components and strong permeable components in the contents. The inorganic vapor deposition layer 23 is formed by the same material and method as those described in the first to third embodiments.

(Gas barrier coat layer)
The gas barrier coat layer 24 has a role of preventing the penetration of volatile components and strong permeable components in the contents in cooperation with the inorganic vapor deposition layer 23. Further, the gas barrier coat layer 24 firmly bonds the inorganic vapor deposition layer 23 and the adhesive layer 3, and prevents a decrease in the laminate strength against the penetration of volatile components and strong permeable components in the contents. Also has a role to play.

  The gas barrier coat layer 24 according to the present embodiment applies an aqueous solution or a water / alcohol mixed solution containing at least one of the components (d) and (e) described in the first to third embodiments onto the inorganic vapor deposition layer 23. And formed by drying and curing.

(Adhesive layer)
Next, the adhesive layer 3 is a layer having a role of firmly bonding the intermediate film substrate 21 and the sealant layer 4. Further, the adhesive layer 3 has a role of preventing a decrease in laminate strength against the penetration of volatile components and strong permeable components. As described above, it is desirable that the gas barrier coat layer 24 and the adhesive layer 3 are directly bonded, but the adhesive layer 3 and the sealant layer 4 are indirectly connected via another resin layer 5 such as polyethylene. It may be bonded. The adhesive layer 3 is formed using an adhesive composed of a bifunctional or higher functional isocyanate compound described in the first to third embodiments. Since the bifunctional or higher functional isocyanate compound is excellent in adhesiveness with the intermediate film substrate 21 (polyamide film) used in the present embodiment and is not easily eroded by volatile components or strong permeable components, A decrease in laminate strength with the sealant layer 4 is significantly suppressed.

(Sealant layer)
The sealant layer 4 is formed by the same material and method as those described in the first to third embodiments.

  As described above, in the fourth embodiment, as the intermediate film 2 located on the inner side of the base film, the primer layer 22, the inorganic vapor deposition layer 23, and the gas barrier coat layer 24 are provided on the intermediate film base 21. The films laminated in order are used, and the intermediate film substrate 21 is bonded to the adhesive layer 3. By adopting such a laminated structure, both the inorganic vapor-deposited layer 23 and the gas barrier coat layer 24 prevent the penetration of volatile components and strong permeable components. Decline can be prevented.

  In the fourth embodiment, since the polyamide film excellent in adhesion to the adhesive layer 3 made of a bifunctional or trifunctional isocyanate compound is used as the intermediate film base 21, the intermediate film base 21 and the sealant are used. Adhesion with the layer 4 (or the resin layer 5) can be strengthened. Due to the strong adhesive strength between the intermediate film substrate 21 and the sealant layer 4 (or the resin layer 5) and the property that the adhesive layer 3 itself is not easily eroded by the volatile component and the strong permeable component, the intermediate film substrate 21 and the sealant A decrease in the laminate strength with the layer 4 is significantly suppressed.

  Furthermore, the primer film 22 is formed of a mixed resin of an oxazoline group-containing water-soluble polymer, a water-based acrylic resin, a water-based urethane resin and / or a water-based polyester resin, so that the intermediate film substrate 21 and the gas barrier coat are formed. The layer 24 can be firmly bonded, and the penetration of volatile components and strongly permeable components can be suppressed.

  Therefore, by adopting the laminated structure according to the fourth embodiment, it is possible to suppress the decrease in the laminate strength between the layers constituting the base film, and the decrease in the laminate strength between the base film and the sealant layer 4. Can also be suppressed. Therefore, the packaging material which concerns on 4th Embodiment is suitable as a packaging material of the content containing a volatile component and a strong permeability component. These technical effects will be described later based on the data of Examples 4 to 6.

  Examples in which the packaging material according to the present invention is specifically implemented will be described below.

Example 1
FIG. 5 is a cross-sectional view of the packaging material according to the first embodiment of the present invention.

  As the outer film 1, a multi-layer film laminated using a dry laminate adhesive was employed. This outer film 1 is a film in which “stretched polyamide film 11 (thickness 15 μm) / printing ink layer 12 / dry laminating adhesive layer 1ad (thickness 4 μm) / aluminum foil 13 (thickness 9 μm)” is laminated in order from the outer side. is there.

  A stretched polyethylene terephthalate film 21 (thickness 12 μm) was used as the intermediate film base 21. On this intermediate film substrate 21, a primer layer 22 (thickness 20 nm), an inorganic vapor deposition layer 23 (thickness 15 nm), and a gas barrier coat layer 24 (thickness 300 nm) were sequentially formed.

  The primer layer 22 is formed as follows. As the silane coupling agent, γ-isocyanatopropyltrimethoxysilane dissolved in a diluting solvent (ethyl acetate) was used. 5 parts by weight of acrylic polyol was mixed and stirred with respect to 1 part by weight of this silane coupling agent. Next, a mixture of XDI and IPDI was employed as the isocyanate compound, and this was added and mixed. The blending amount is such that the isocyanate group of the isocyanate compound is equivalent to the hydroxyl group of the acrylic polyol. Further, a solution adjusted to a solid content concentration of 2% by adding a solvent is applied to the intermediate film base material 21 by a gravure coating method, dried by heating, and each component is reacted and cured to form a primer layer 22. Formed.

  The inorganic vapor deposition layer 23 was formed on the primer layer 22 by vacuum vapor deposition of silicon oxide.

The gas barrier coat layer 24 is formed as follows. Using tetraethoxysilane as the silicon alkoxide, 89.6 parts by weight of 0.1N hydrochloric acid was added to 10.4 parts by weight of the silicon alkoxide and stirred for 30 minutes to produce a hydrolyzed solution of silicon alkoxide. . Its solid content concentration in terms of SiO ₂ was 3% by weight.

  Moreover, polyvinyl alcohol (PVA) was employ | adopted as a water-soluble polymer, and the PVA solution which melt | dissolved this in the solvent was prepared. The solvent is a mixture of water and isopropyl alcohol in a weight ratio of 90:10. The concentration of the PVA solution is 3.0% by weight.

  Then, a solution obtained by mixing the hydrolyzed solution of silicon alkoxide and the PVA solution at a weight ratio of 60:40 is applied onto the inorganic vapor deposition layer 23 as a coating solution, and dried by heating. The components were reacted and cured to form a gas barrier coat layer 24.

  Next, as the sealant layer 4, a linear low density polyethylene sheet (thickness 40 μm) was prepared. And after apply | coating an adhesive agent on the gas barrier coat layer 24 of the intermediate | middle film 2 and forming the contact bonding layer 3 (thickness 200nm), another resin layer 5 (thickness 15micrometer) fuse | melted on this contact bonding layer 3 is extruded. Coating was performed, and the sealant layer 4 was stacked while the resin layer 5 was in a molten state. For the adhesive layer 3, an adhesive mainly composed of a hexamethylene diisocyanate burette body (trifunctional isocyanate compound) was used.

  Finally, the aluminum foil 13 of the outer film 1 and the intermediate film base material 21 were bonded with an adhesive ad for dry lamination (thickness: 4 μm) to produce a packaging material according to Example 1.

  As shown in the cross-sectional view of FIG. 5, the packaging material obtained in this way was “stretched polyamide film 11 / printing ink layer 12 / dry laminating adhesive layer 1ad / aluminum foil 13 / dry laminating adhesive ad” from the outside. / Intermediate film substrate 21 / primer layer 22 / inorganic vapor deposition layer 23 / gas barrier coat layer 24 / adhesive layer 3 / resin layer 5 / sealant layer 4 ”.

(Example 2)
FIG. 6 is a cross-sectional view of a packaging material according to Example 2 of the present invention.

  As the outer film 1, a film having a multilayer structure laminated by using a resin layer was employed instead of using an adhesive for dry lamination. This outer film 1 is a film in which “printing ink layer 12 / polyethylene resin layer 14 (thickness 20 μm) / paper substrate 15 / polyethylene resin layer 16 (thickness 15 μm) / aluminum foil 13 (thickness 9 μm)” are laminated in order from the outside. It is.

  The outer film 1 is extruded from an extruder in a molten state of the polyethylene resin and laminated on one side of the paper substrate 15 to form a polyethylene resin layer 14, and the polyethylene resin is also formed on the opposite side of the paper substrate 15. Is extruded in a molten state to form a polyethylene resin layer 16, and the aluminum foil 13 is laminated and adhered while the polyethylene resin layer 16 is in a molten state.

  A packaging material was produced in the same manner as in Example 1 except that this outer film 1 was used. As shown in the cross-sectional view of FIG. 6, the packaging material thus obtained is “from the outside,“ printing ink layer 12 / polyethylene resin layer 14 / paper substrate 15 / polyethylene resin layer 16 / aluminum foil 13 / adhesion for dry lamination ”. It has a layer structure of “agent ad / intermediate film substrate 21 / primer layer 22 / inorganic vapor deposition layer 23 / gas barrier coat layer 24 / adhesive layer 3 / resin layer 5 / sealant layer 4”.

(Example 3)
FIG. 7 is a cross-sectional view of a packaging material according to Example 3 of the present invention.

In Example 1 (FIG. 5), the outer film 1 having the aluminum foil 13 as the gas barrier layer was used. In Example 3, the outer film including a film having a thin film of Al ₂ O ₃ was used instead of the aluminum foil 13. Film 1 was employed. A film including a thin film of Al ₂ O _{3 is} a film in which an Al ₂ O ₃ vapor deposition layer is provided on one side of a stretched polyamide film.

The outer film 1 employed in this example is “stretched polyethylene terephthalate film 17 (thickness: 12 μm) / printing ink layer 12 / adhesive layer for dry lamination 1ad / Al ₂ O ₃ vapor deposition film 18 (thickness: 15 μm)” from the outside. It is the film which laminated | stacked.

A packaging material was produced in the same manner as in Example 1 except that this outer film 1 was used. As shown in the cross-sectional view of FIG. 7, the packaging material obtained in this way was “stretched polyethylene terephthalate film 17 (thickness 12 μm) / printing ink layer 12 / dry laminating adhesive layer 1ad / Al ₂ O ₃ vapor deposition from the outside. The layer structure of “film 18 (thickness 12 μm) / adhesive ad for dry lamination / intermediate film substrate 21 / primer layer 22 / inorganic vapor deposition layer 23 / gas barrier coat layer 24 / adhesive layer 3 / resin layer 5 / sealant layer 4” I have it.

(Comparative Example 1)
FIG. 8 is a cross-sectional view of a packaging material according to Comparative Example 1.

  Next, a comparative example will be described for the purpose of comparison with the present invention. First, in Comparative Example 1, the adhesive described in Patent Document 2 was used as the adhesive layer 3, but as an intermediate film, “a primer layer, an inorganic vapor deposition layer, and a gas barrier coat layer were laminated in this order on the intermediate film substrate. This is an example in which a stretched polyamide film is employed without employing a “film”.

In this example, an SiO ₂ vapor deposition film 19 (thickness 12 μm) in which a silicon oxide thin film was formed on a stretched polyethylene terephthalate film was employed as the outer film 1. Further, a stretched polyamide film 2 ′ (thickness: 15 μm) was adopted as an intermediate film.

And the packaging material was manufactured similarly to Example 1. That is, first, an adhesive is applied onto the intermediate film 2 to form an adhesive layer 3 (thickness 200 nm), and then another molten resin layer 5 (thickness 15 μm) is extruded onto the adhesive layer 3 and coated. While the resin layer 5 was in a molten state, the sealant layer 4 was laminated. For the adhesive layer 3, an adhesive mainly composed of a hexamethylene diisocyanate burette body (trifunctional isocyanate compound) was used. The sealant layer 4 was a linear low-density polyethylene sheet (thickness 40 μm). Then, production and SiO ₂ deposited film 19 is an outer film, and a stretched polyamide film 2 'which is an intermediate film, and bonded by dry laminating adhesive ad (thickness 4 [mu] m), the packaging material according to Comparative Example 1 did.

As shown in the cross-sectional view of FIG. 8, the packaging material obtained in this manner was “SiO ₂ vapor deposition film 19 / adhesive ad for dry lamination ad / stretched polyamide film 2 ′ / adhesive layer 3 / resin layer 5 / sealant from the outside. It has a layer configuration of “layer 4”.

(Comparative Example 2)
FIG. 9 is a cross-sectional view of a packaging material according to Comparative Example 2.

  In this example, instead of using an adhesive mainly composed of hexamethylene diisocyanate burette (trifunctional isocyanate compound) as the adhesive layer 3 in Comparative Example 1, a general two-component curing for dry lamination is used. This is an example employing a mold adhesive.

First, an adhesive is applied onto the intermediate film 2 to form an adhesive layer 3 ′ (thickness: 200 nm), and then another molten resin layer 5 (thickness: 15 μm) is extruded onto the adhesive layer 3 ′ and coated. While the resin layer 5 was in a molten state, the sealant layer 4 was laminated. A two-component curable adhesive for dry lamination was used for the adhesive layer 3 ′. The sealant layer 4 was a linear low-density polyethylene sheet (thickness 40 μm). Then, production and SiO ₂ deposited film 19 is an outer film, and a stretched polyamide film 2 'which is an intermediate film, and bonded by dry laminating adhesive ad (thickness 4 [mu] m), the packaging material according to Comparative Example 2 did.

As shown in the cross-sectional view of FIG. 9, the packaging material obtained in this way is “SiO ₂ vapor deposition film 19 / two-component curable adhesive layer ad for dry lamination ad / stretched polyamide film 2 ′ / adhesive layer 3 ′” from the outside. / Resin layer 5 / sealant layer 4 ”.

(Comparative Example 3)
FIG. 10 is a cross-sectional view of a packaging material according to Comparative Example 3.

  Comparative Example 3 is an example in which the front and back of the intermediate film of Example 1 are arranged in reverse. That is, as shown in the sectional view of FIG. 10, the packaging material obtained in this example was “stretched polyamide film 11 / printing ink layer 12 / dry laminating adhesive layer 1ad / aluminum foil 13 / dry laminate” from the outside. Adhesive layer ad / gas barrier coating layer 24 / inorganic vapor deposition layer 23 / primer layer 22 / intermediate film substrate 21 / adhesive layer 3 / resin layer 5 / sealant layer 4 ”.

(Evaluation)
About the packaging material which concerns on Examples 1-3 and the packaging material which concerns on Comparative Examples 1-3, the temporal change was evaluated. The evaluation method is as follows. First, a packaging bag was produced from the packaging materials obtained in each of the examples and comparative examples, and the contents containing a strong osmotic component were stored in the packaging bag and sealed, and then stored at 50 ° C. for 1 month. . The contents are curling agents and contain 5% by weight of cysteamine as a strong penetrating component. The adhesive strength and oxygen permeability before and after storage were measured. As for the adhesive strength, the part having the lowest adhesive strength, that is, the peeled position was also observed. In addition, the appearance was also visually observed.

  If the oxygen permeability after storage is increased compared with the oxygen permeability before storage, it can be seen that the gas barrier property of the packaging material is deteriorated with time. In addition, if the adhesive strength after storage is reduced compared to the adhesive strength before storage of the packaging material, it is estimated that the deterioration of the laminate strength of each layer over time is the cause of the gas barrier property deterioration over time. it can. Further, by specifying the peeling position, it is possible to estimate the cause of the deterioration of the laminate strength with time.

  On the other hand, if the oxygen permeability before storage and the oxygen permeability after storage are substantially the same, and the adhesive strength before storage and the adhesive strength after storage are also approximately the same, the packaging material contains a strong penetrating component. Despite the storage and storage of curling agent, the laminate strength has durability that does not deteriorate with time, and it can be understood that the durability of the gas barrier property is excellent based on the durability of the laminate strength. .

  In addition, in the case where the adhesive strength before storage and the adhesive strength after storage are almost equal even though the oxygen permeability after storage is increased compared to the oxygen permeability before storage, the gas barrier It can be estimated that the deterioration of sex over time is due to another cause. However, as described later, such a phenomenon could not be observed. Therefore, within the scope of this experiment, it can be reasonably estimated that the cause of the deterioration of the gas barrier property with time is the deterioration of the laminate strength with time, and there is no other cause.

  The oxygen permeability was measured in an atmosphere of 30 ° C. and 70% RH using OXTRAN-10 / 50A manufactured by Modern Control.

  Moreover, the adhesive strength was measured by cutting out a sample having a width of 15 mm from each packaging bag and peeling it 180 degrees with this Tensilon type tensile tester. The tensile speed was 300 mm / min.

  The results are shown in Table 1. Appearance was evaluated as “x” when abnormality was observed by visual observation, and as “◯” when there was no problem.

(Discussion)
As an intermediate film, “a film in which a primer layer, an inorganic vapor deposition layer and a gas barrier coat layer are laminated in this order on an intermediate film substrate” is not adopted, and an adhesive layer is generally used instead of “bifunctional or higher isocyanate compound”. In Comparative Example 2 employing a typical two-pack curable adhesive for dry laminating, the oxygen permeability increased greatly from 1.5 ml / m ² / MPa before storage to 10.0 ml / m ² / MPa after storage doing. Therefore, it turns out that the packaging material of the comparative example 2 is inferior in the durability of the gas-barrier property, when a strong permeability component is accommodated and preserved. Moreover, since the adhesive strength between the stretched polyamide film 2 ′ and the sealant layer 4 is the smallest, and the adhesive strength is also reduced from 7.2 N / 15 mm width before storage to 1.0 N / 15 mm width, It can be presumed that the cause is the deterioration of the laminate strength between the stretched polyamide film 2 ′ and the sealant layer 4 with time.

In Comparative Example 1 in which “bifunctional or higher functional isocyanate compound” is used as an adhesive layer for bonding the stretched polyamide film 2 ′ and the sealant layer 4, the adhesive strength before storage (7.2 N / 15 mm width) is high. However, when the strongly permeable component is accommodated and stored, the adhesive strength between the outer film (SiO ₂ vapor-deposited film 19) and the intermediate film (stretched polyamide film 2 ′) rapidly decreases over time (0.8 N / 15 mm width). Along with this, the gas barrier properties also deteriorate with time.

From the above results, the adhesive strength between the intermediate film (stretched polyamide film 2 ′) and the sealant layer 4 can be improved by adopting a “bifunctional or higher functional isocyanate compound” as an adhesive layer for bonding the two. Even when the strong osmotic component was housed and stored, deterioration over time could be prevented. On the other hand, the deterioration over time of the adhesive strength between the outer film (SiO ₂ vapor-deposited film 19) and the intermediate film (stretched polyamide film 2 ′) is improved even if “bifunctional or higher isocyanate compound” is used as the adhesive layer. I couldn't do it, but rather the deterioration got bigger.

  On the other hand, “Bifunctional or higher isocyanate compound” is used as the adhesive layer, and “Film with the primer layer, inorganic vapor deposition layer, and gas barrier coat layer laminated in this order on the intermediate film substrate” is used as the intermediate film. In Examples 1 to 3, the oxygen permeability before storage and the oxygen permeability after storage are substantially the same, the adhesive strength before storage and the adhesive strength after storage are also approximately the same, and the strong permeability component It was confirmed that the laminate strength and the gas barrier property were excellent even when stored and stored.

  That is, in Examples 1 to 3, the adhesive strength between the intermediate film 2 and the sealant layer 4 can be increased by using “bifunctional or higher isocyanate compound” as the adhesive layer, and the deterioration with time is also suppressed. did it. In addition, by adopting a laminated structure of “intermediate film substrate 21 / primer layer 22 / inorganic vapor deposition layer 23 / gas barrier coat layer 24” as the intermediate film 2, the adhesive strength between the outer film 1 and the intermediate film 2 is adopted. It was also possible to suppress deterioration over time. For this reason, the packaging material which concerns on Examples 1-3 has high adhesive strength between each layer, and even if it accommodated and preserve | save the strong permeability component, it was able to suppress the temporal deterioration. And since the adhesive strength between each layer does not deteriorate with time in this way, it is difficult for the gas barrier property to deteriorate with time.

  The oxygen permeability before storage of the packaging materials of Examples 1 to 3 is smaller by one digit or more than the oxygen permeability before storage of the packaging materials of Comparative Examples 1 and 2, and therefore excellent in terms of initial gas barrier properties. It was.

  Next, as the intermediate film, “a film in which a primer layer, an inorganic vapor deposition layer, and a gas barrier coat layer are laminated in this order on an intermediate film substrate” is adopted, and “bifunctional or higher functional isocyanate compound” is adopted as an adhesive layer. Nevertheless, in Comparative Example 3 in which the front and back of the intermediate film are reversed from those of Examples 1 to 3, the adhesive strength between the intermediate film 2 and the sealant layer 4 deteriorates with time. From this result, it can be understood that the durability of the laminate strength and the arrangement of the front and back of the intermediate film have a close relationship. In Comparative Example 3, the gas barrier property does not decrease with time, but it can be presumed that the gas barrier property is maintained by the aluminum foil.

Example 4
FIG. 11 is a cross-sectional view of a packaging material according to Examples 4 to 6 of the present invention.

  As the outer film 1, a multi-layer film laminated using a dry laminate adhesive was employed. This outer film 1 is a film in which “polyethylene terephthalate film 14 (thickness 12 μm) / printing ink layer 12 / dry laminating adhesive layer 1ad (thickness 3 μm) / aluminum foil 13 (thickness 9 μm)” is laminated in order from the outer side. is there.

  Further, a nylon film (thickness 15 μm) was used as the intermediate film substrate 21. On this intermediate film substrate 21, a primer layer 22 (thickness 20 nm), an inorganic vapor deposition layer 23 (thickness 15 nm), and a gas barrier coat layer 24 (thickness 300 nm) were sequentially formed.

  For the primer layer 22, a resin mixture prepared by mixing 20 parts by weight of a water-soluble polymer having an oxazoline group, 30 parts by weight of an aqueous acrylic resin, and 50 parts by weight of an aqueous urethane resin is prepared. It was formed by applying on a nylon film 25 and curing.

  The inorganic vapor deposition layer 23 was formed on the primer layer 22 by vacuum vapor deposition of silicon oxide.

The gas barrier coat layer 24 was prepared by adding 89.6 parts by weight of 0.1N hydrochloric acid to 10.4 parts by weight of tetraethoxysilane and stirring for 30 minutes to obtain a hydrolyzed silicon alkoxide solution. Its solid content concentration in terms of SiO ₂ was 3% by weight. Moreover, the polyvinyl alcohol (PVA) was used as a water-soluble polymer, and the PVA solution which melt | dissolved this in the solvent was prepared. The solvent used was a mixture of water and isopropyl alcohol in a weight ratio of 90:10. The concentration of the PVA solution was 3.0% by weight.

  Then, a solution obtained by mixing the hydrolyzed solution of silicon alkoxide and the PVA solution at a weight ratio of 60:40 is applied onto the inorganic vapor deposition layer 23 as a coating solution, and dried by heating. The components were reacted and cured to form a gas barrier coat layer 24.

  Next, as the sealant layer 4, a linear low density polyethylene sheet (thickness 40 μm) was prepared. And after apply | coating an adhesive agent on the intermediate | middle film base material 21 and forming the contact bonding layer 3 (thickness 200nm), the melted polyethylene is extruded on this contact bonding layer 3, and the resin layer 5 (thickness 15micrometer) is formed, While the resin layer 5 was in a molten state, the sealant layer 4 was laminated. For the adhesive layer 3, an adhesive mainly composed of a hexamethylene diisocyanate burette body (trifunctional isocyanate compound) was used.

  Finally, the aluminum foil 13 of the outer film 1 and the gas barrier coat layer 24 were bonded with an adhesive ad for dry lamination (thickness: 3 μm) to produce a packaging material according to Example 4.

  As shown in the cross-sectional view of FIG. 11, the packaging material thus obtained was “from the outside,“ polyethylene terephthalate film 14 / printing ink layer 12 / dry laminating adhesive layer 1ad / aluminum foil 13 / dry laminating adhesive ad ”. / Gas barrier coat layer 24 / inorganic vapor deposition layer 23 / primer layer 22 / nylon film 21 / adhesive layer 3 / resin layer 5 / sealant layer 4 ”.

(Example 5)
The packaging material according to Example 5 is a resin obtained by mixing 20 parts by weight of a water-soluble polymer having an oxazoline group, 30 parts by weight of an aqueous acrylic resin, and 50 parts by weight of an aqueous polyester resin as a material for forming the primer layer 22 It was produced by the same material and method as the packaging material according to Example 4 except that the mixture was used.

(Example 6)
In the packaging material according to Example 5, as a material for forming the primer layer 22, 20 parts by weight of a water-soluble polymer having an oxazoline group, 30 parts by weight of an aqueous acrylic resin, and a mixture 50 of an aqueous urethane resin and an aqueous polyester resin It was manufactured by the same material and method as the packaging material according to Example 4 except that a resin mixture mixed with parts by weight was used.

(Comparative Example 4)
FIG. 12 is a cross-sectional view of the packaging material according to Comparative Examples 4 and 5.

  As the outer film 1, “polyethylene terephthalate film 31 (thickness 12 μm) / primer layer 32 (thickness 20 nm) / inorganic vapor deposition layer 33 (thickness 15 nm) / gas barrier coat layer 34 (thickness 300 nm) / printing ink layer 12” The film which laminated | stacked was used. The primer layer 32, the inorganic vapor deposition layer 33, and the gas barrier coat layer 34 were formed by the same materials and methods as the primer layer 22, the inorganic vapor deposition layer 23, and the gas barrier coat layer 24 of Example 4.

  Further, a stretched nylon film 25 (thickness: 15 μm) was used as the intermediate film 2 ′.

  Next, as the sealant layer 4, a linear low density polyethylene sheet (thickness 40 μm) was prepared. And after apply | coating an adhesive agent on intermediate | middle film 2 'and forming the contact bonding layer 3 (thickness 200nm), the melted polyethylene is extruded on this contact bonding layer 3, and the resin layer 5 (thickness 15micrometer) is formed, this While the resin layer 5 was in a molten state, the sealant layer 4 was laminated and laminated. For the adhesive layer 3, an adhesive mainly composed of a hexamethylene diisocyanate burette body (trifunctional isocyanate compound) was used.

  Finally, the gas barrier coat layer 34 and the printing ink layer 12 of the outer film 1 are bonded to the intermediate film base material 21 with a dry laminate adhesive ad (thickness 4 μm) to produce a packaging material according to Comparative Example 4. did.

  As shown in the cross-sectional view of FIG. 12, the packaging material obtained in this manner was “from the outside,“ polyethylene terephthalate film 31 / primer layer 32 / inorganic vapor deposition layer 33 / gas barrier coat layer 34 / printing ink layer 12 / adhesive for dry lamination ”. It has a layer structure of “agent layer ad / stretched nylon film 2 ′ / adhesive layer 3 / resin layer 5 / sealant layer 4”.

(Comparative Example 5)
The packaging material according to Comparative Example 5 was manufactured by the same material and method as the packaging material according to Comparative Example 4 except that the adhesive layer 3 ′ was formed using a two-component curable polyurethane adhesive.

(Comparative Example 6)
FIG. 13 is a cross-sectional view of a packaging material according to Comparative Example 6.

  The packaging material according to Comparative Example 6 was manufactured by the same material and method as the packaging material according to Example 4 except that the forming material of the primer layer 42 and the material of the intermediate film substrate 21 of the intermediate film 2 were different.

  The primer layer 42 was formed by the following method. The primer layer 22 is formed as follows. As the silane coupling agent, γ-isocyanatopropyltrimethoxysilane dissolved in a diluting solvent (ethyl acetate) was used. 5 parts by weight of acrylic polyol was mixed and stirred with respect to 1 part by weight of this silane coupling agent. Next, a mixture of XDI and IPDI was employed as the isocyanate compound, and this was added and mixed. The blending amount is such that the isocyanate group of the isocyanate compound is equivalent to the hydroxyl group of the acrylic polyol. Further, a solution adjusted to a solid content concentration of 2% by adding a solvent is applied to the intermediate film substrate 21 by a gravure coating method, heated and dried, and each component is reacted and cured to form a primer layer 42. Formed.

  A polyethylene terephthalate film (thickness 12 μm) was used for the intermediate film base 21.

(Evaluation)
Using the packaging materials according to Examples 4 to 6 and the packaging materials according to Comparative Examples 4 to 6, the contents were subjected to a storage test by the same method as in Examples 1 to 3, and the oxygen permeability and adhesive strength before and after the storage. In addition, the appearance of the packaging material was evaluated. The results are shown in Table 2.

(Discussion)
In the packaging material according to Comparative Example 4, since the adhesive layer 3 is formed using a hexamethylene diisocyanate burette body excellent in adhesiveness with the stretched nylon film as the intermediate film substrate 21, the intermediate film 2 and the sealant layer 4 are formed. No peeling was observed. However, the strong osmotic component contained in the content permeates the intermediate film substrate 21 and erodes the dry laminate adhesive layer between the outer film 1 and the intermediate film 2, and the outer film 1 and the intermediate film 2 The adhesive strength during the period was greatly reduced from 7.2 N / 15 mm width to 0.8 N / 15 mm width before and after storage of the contents. Along with this, gas barrier properties also deteriorated.

In the packaging material according to Comparative Example 5, since the adhesive layer 3 was formed using a two-component curable polyurethane adhesive, the adhesive strength between the intermediate film 2 and the sealant layer 4 was 7 before and after storage of the contents. .2N / 15mm width greatly decreased to 1.0N / 15mm width. Further, the oxygen permeability was greatly increased from 1.5 ml / m ² / MPa before storage to 10.0 ml / m ² / MPa after storage, and the gas barrier properties were deteriorated.

  In the packaging material according to Comparative Example 6, the adhesive layer 3 was formed using a hexamethylene diisocyanate burette body, and the polyethylene terephthalate film was attached to the intermediate film substrate 21 bonded to the sealant layer 4 via the adhesive layer 3. Therefore, the adhesive strength between the adhesive layer 3 and the intermediate film substrate 21 is not maintained, and the adhesive strength increases from 4.5 N / 15 mm width to 0.2 N / 15 mm width before and after storage of the contents. Declined. In the packaging material according to Comparative Example 6, there was almost no change in oxygen permeability before and after storage of the contents. This is probably because the outer film 1 of the packaging material according to Comparative Example 6 is provided with a gas barrier layer made of an aluminum foil, so that the oxygen permeability is maintained by the aluminum foil. However, since the gas barrier layer and the gas barrier coat layer are bonded via the dry laminate adhesive layer, the dry laminate adhesive is eroded by the strong osmotic component contained in the contents, and in appearance, in some places. Bubbles were observed.

  On the other hand, in the packaging materials according to Examples 4 to 6, “bifunctional or higher functional isocyanate compound” is used as the adhesive layer 3, and “gas barrier coat layer 24 / inorganic vapor deposition layer 23 / primer layer 22 / An intermediate base material layer 21 / adhesive layer 3 / sealant layer 4 made of a polyamide film is used. Further, the primer layer 22 is composed of a water-soluble polymer containing an oxazoline group, a water-based acrylic resin, a water-based urethane resin, and / or Alternatively, by using the “resin mixture containing an aqueous polyester-based resin”, a decrease in the adhesive strength between the intermediate film 2 and the sealant layer 4 was suppressed before and after storage of the contents. Further, from the appearance of the packaging material, no more than delamination was observed. Further, the oxygen permeability hardly changed before and after storage of the contents, and the gas barrier property was maintained. In addition to the function of the aluminum foil contained in the outer film 1, the maintenance of this gas barrier property is actually suppressed by the adhesive layer 3 and the primer layer 22 from lowering the laminate strength of each layer of the intermediate film 2 and the sealant layer 4. It is thought that this is also secured.

  From the above results, the adhesive strength between the intermediate film substrate 21 (polyamide film) and the sealant layer 4 is such that each layer constituting the intermediate film 2 is formed by forming the adhesive layer 3 for adhering both together with a bifunctional or higher functional isocyanate compound. 4 and the primer layer 22 is formed of the above-described material, it is possible to suppress deterioration over time even when a packaging material is used for storing and storing a strongly permeable component. It could be confirmed.

  INDUSTRIAL APPLICABILITY The present invention can be used as a packaging material for packaging contents containing volatile components and strong penetrating components such as chemicals and curling agents.

1 .. Outer film 11 .. Stretched polyamide film 12 .. Printing ink layer 13 .. Aluminum foil 14 .. Polyethylene resin layer 15 .. Paper substrate 16 .. Polyethylene resin layer 17 .. Stretched polyethylene terephthalate film 18 .. Al ₂ O ₃ vapor deposition film 19 ·· SiO ₂ vapor deposition film 1ad ·· Dry laminating adhesive layer 2 ·· Intermediate film 21 ·· Intermediate film substrate 22 ·· Primer layer 23 ·· Inorganic vapor deposition layer 24 ·· Gas barrier coating Layer 3 ·· Adhesive layer 3 '·· Adhesive layer 4 · · Sealant layer ad · · Adhesive layer

Claims (6)

In a packaging material composed of a base film, an adhesive layer and a sealant layer laminated in this order, the adhesive layer is composed of a bifunctional or higher functional isocyanate compound,
The base film includes an intermediate film in which a primer layer, an inorganic vapor deposition layer, and a gas barrier coat layer are laminated in this order on an intermediate film base made of polyamide,
The intermediate film substrate is bonded to the sealant layer via the adhesive layer;
The packaging material, wherein the primer layer is formed of a resin mixture containing an oxazoline group-containing water-soluble polymer, an aqueous acrylic resin, an aqueous urethane resin and / or an aqueous polyester resin. The gas barrier coat layer, and a water-soluble polymer, the coating solution was applied containing the following (d) or (e), characterized in that it is a layer formed by drying and curing, according to claim 1 Packaging materials.
(D) metal alkoxide, silicon alkoxide, or a hydrolyzate thereof (e) tin chloride The adhesive layer is a layer formed from an adhesive mainly composed of a trifunctional or higher functional isocyanate compound composed of a derivative of an isocyanate monomer, and the isocyanate compound is an adduct type, burette type or isocyanurate type isocyanate. The packaging material according to claim 1, wherein the packaging material is a compound. The base film is further characterized in that it comprises an outer film laminated via the adhesive layer to the gas barrier coating layer on the previous SL intermediate film, packaging material according to any one of claims 1 to 3 . The packaging material according to claim 4 , wherein the adhesive layer between the outer film and the intermediate film is formed from an adhesive for dry lamination. The packaging material according to claim 4 , wherein the outer film is composed of a single layer film or a multilayer film.

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