Laminate for aroma-retaining packaging bag and packaging bag

Abstract

To provide a laminate that can maintain high gas barrier properties (oxygen barrier property and vapor barrier property) and is suitably applicable as a packaging bag having aroma-retaining property.SOLUTION: The laminate for an aroma-retaining packaging bag comprises at least a base material, an adhesive layer and a vapor-deposited layer. The adhesive layer is formed of a cured product of a two-liquid curing type adhesive including: a polyester polyol selected from the group consisting of a polyester polyol being a polycondensation product of an ortho-oriented polyvalent carboxylic acid or an anhydride thereof with a polyhydric alcohol, a polyester polyol having a glycerol skeleton and a polyester polyol having an isocyanuric ring; and an isocyanate compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate for aroma-retaining packaging bags and a packaging bag equipped with the laminate. [Background technology]

[0002] Conventionally, resin films made from resin materials have been used as the constituent material for packaging bags. Packaging bags require various functions such as oxygen barrier properties and water vapor barrier properties depending on the contents they are filled with, so laminates made from multiple resin films are widely used. For example, in Patent Document 1, aluminum foil is provided in the laminate to improve barrier properties. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2010-149389 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the aluminum foil contained in the laminate disclosed in Patent Document 1 is thick, and packaging bags made using it have the problem of high energy costs and environmental burden when disposed of and recycled.

[0005] The inventors attempted to apply an aluminum vapor-deposited layer that is much thinner than aluminum foil in order to reduce environmental impact. However, they encountered a problem in that the gas barrier properties deteriorated when large bending loads were applied during the production of the packaging bag and when filling it with contents.

[0006] In order to solve the above problems, the inventors conducted research and found that by combining an aluminum vapor-deposited layer with a specific adhesive, the decrease in gas barrier properties when a bending load is applied can be suppressed. Furthermore, the inventors found that by using the vapor-deposited layer in combination with the above-mentioned specific adhesive, not only is the decrease in gas barrier properties suppressed, but the packaging bag also acquires fragrance retention properties.

[0007] Therefore, an object of the present invention is to provide a laminate that can maintain high gas barrier properties (oxygen barrier properties and water vapor barrier properties) and is suitable for use as a packaging bag with aroma retention properties. Another object of the present invention is to provide an aroma retention packaging bag to which the above-described laminate is applied. [Means for solving the problem]

[0008] The present invention relates to a laminate for aroma-retaining packaging bags comprising at least a base material, an adhesive layer, and a vapor-deposited layer, wherein the adhesive layer is characterized by comprising a cured product of a two-component curable adhesive containing a polyester polyol selected from the group consisting of a polyester polyol which is a polycondensate of an ortho-oriented polycarboxylic acid or its anhydride and a polyhydric alcohol, a polyester polyol having a glycerol skeleton, and a polyester polyol having an isocyanuric ring, and an isocyanate compound.

[0009] In the laminate according to the present invention, a sealant layer may be further provided on the vapor-deposited layer side, and the substrate and the sealant may contain the same resin material.

[0010] In the laminate according to the present invention, the same resin material may be polypropylene.

[0011] In the laminate according to the present invention, the vapor-deposited layer may be an aluminum vapor-deposited layer.

[0012] In the laminate according to the present invention, an intermediate layer may be further provided between the vapor-deposited layer and the sealant layer.

[0013] In the laminate according to the present invention, 90% by mass or more of the resin constituting the laminate may be made of the same resin material.

[0014] In the laminate according to the present invention, the adhesive layer may have a thickness of 0.5 μm or more and 6 μm or less.

[0015] In the laminate according to the present invention, the vapor deposition layer may have a thickness of 1 nm or more and 140 nm or less.

[0016] The present invention is a fragrance-retaining packaging bag including the above laminate.

Effects of the Invention

[0017] According to the present invention, it is possible to maintain high gas barrier properties and provide a laminate that can be suitably applied as a fragrance-retaining packaging bag. Further, according to the present invention, it is possible to provide a fragrance-retaining packaging bag to which the above-described laminate is applied.

Brief Description of the Drawings

[0018] [Figure 1] It is a schematic cross-sectional view showing an embodiment of the laminate of the present invention. [Figure 2] It is a schematic cross-sectional view showing an embodiment of the laminate of the present invention. [Figure 3] It is a schematic cross-sectional view showing an embodiment of the laminate of the present invention. [Figure 4] It is a front view showing an example of a packaging bag including the laminate of the present invention and a zipper tape. [Figure 5] It is a front perspective view showing an example of a packaging bag including the laminate of the present invention and a zipper tape. [Figure 6] It is a rear perspective view showing an example of a packaging bag including the laminate of the present invention and a zipper tape. [Figure 7] It is a front view showing an example of a packaging bag including the laminate of the present invention and a zipper tape.

Modes for Carrying Out the Invention

[0019] (Laminated structure) As shown in Figure 1, the laminate 10 of the present invention comprises a base material 11, an adhesive layer 12, and a vapor-deposited layer 13. In one embodiment, as shown in Figure 2, the laminate 10 further comprises a sealant layer 14 on the vapor-deposited layer 13 side. Furthermore, in one embodiment, as shown in Figure 3, the laminate 10 further comprises an intermediate layer 15 between the vapor-deposited layer 13 and the sealant layer 14. Each layer will be described below.

[0020] (base material) The substrate includes at least one type of resin material. Examples of resin materials include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylenedimethylene terephthalate, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer; polyamides such as nylon 6 and nylon 6,6; polyolefins such as polyethylene (PE), polypropylene (PP), and polymethylpentene; vinyl resins such as polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and polyvinylpyrrolidone (PVP); (meth)acrylic resins such as polyacrylate, polymethacrylate, and polymethyl methacrylate; cellophane, cellulose resins such as cellulose acetate, nitrocellulose, cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB); styrene resins such as polystyrene (PS); and chlorinated resins thereof. Among these, polyolefins and polyesters are preferred from the viewpoint of recyclability, as will be discussed later, polyethylene, polypropylene and polyethylene terephthalate are more preferred, and polypropylene is particularly preferred. In this invention, "(meth)acrylic" means that both "acrylic" and "methacrylic" are included. Also, "(meth)acrylate" means that both "acrylate" and "methacrylate" are included.

[0021] Polypropylene may be a homopolymer, a random copolymer, or a block copolymer. A polypropylene homopolymer is a polymer of propylene alone; a polypropylene random copolymer is a random copolymer of propylene and other α-olefins other than propylene (e.g., ethylene, butene-1, 4-methyl-1-pentene, etc.); and a polypropylene block copolymer is a copolymer having polymer blocks made of propylene and polymer blocks made of the above-mentioned α-olefins other than propylene.

[0022] When the laminate of the present invention includes a sealant layer, it is preferable that the base material contains the same resin material as the sealant layer. This eliminates the need to separate the bonded layers when recycling them, thereby improving recyclability. Furthermore, using such a laminate in a packaging bag results in a packaging bag with a lower environmental impact. The same resin material may be polypropylene. In this invention, "identical resin material" means that the resins belong to the same classification.

[0023] In the present invention, it is preferable that 90% or more by mass of the resin constituting the laminate is made of the same resin material. This can further improve recyclability. Preferably, 92% or more by mass, and more preferably 94% or more by mass, of the laminate is made of the same resin material. Furthermore, the content of the same resin material constituting the laminate refers to the ratio of the same resin material to the sum of the resin material content in each layer constituting the laminate.

[0024] The base material may be a stretched resin film. This provides sufficient strength and heat resistance for use as a packaging bag. The stretched resin film may be a uniaxially oriented resin film or a biaxially oriented resin film. Alternatively, a stretched polypropylene resin film made of polypropylene may be used.

[0025] The base material may be a laminate of two or more resin films as described above. The resin film laminate can be manufactured using methods such as dry lamination, wet lamination, and extrusion.

[0026] Within the limits that do not impair the properties of the present invention, the substrate may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic particles, organic particles, mold release agents, and dispersants.

[0027] The substrate may have an image formed on its surface. It is preferable to form the image on the surface of the substrate on the adhesive layer side, as described later, in order to prevent the formed image from coming into contact with the outside air. Furthermore, the resulting images are not particularly limited and may represent letters, patterns, symbols, and combinations thereof. Image formation can be performed using conventionally known inks, but it is preferable to use biomass-derived inks. This makes it possible to produce packaging bags with a lower environmental impact using laminates. The method of image formation is not particularly limited, and examples include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing.

[0028] The substrate is preferably surface-treated. This improves adhesion with adjacent layers. The surface treatment method is not particularly limited and includes, for example, physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0029] The thickness of the base material is preferably 5 μm to 150 μm, and more preferably 10 μm to 100 μm. This improves the mechanical strength and processability of the laminate.

[0030] (adhesive layer) The adhesive layer is characterized by comprising a cured product of a two-component curable adhesive containing a polyester polyol selected from the group consisting of a polyester polyol which is a polycondensate of an ortho-oriented polycarboxylic acid or its anhydride and a polyhydric alcohol, a polyester polyol having a glycerol skeleton, and a polyester polyol having an isocyanuric ring, and an isocyanate compound. When a laminate with a vapor-deposited layer is used in a packaging bag, bending loads are applied to the laminate by a molding machine, etc., which may cause cracks in the vapor-deposited layer. By making the adhesive layer a cured product of the above two-component curable adhesive, even if cracks occur in the vapor-deposited layer, the oxygen barrier and water vapor barrier properties of the laminate can be maintained, and the aroma retention can be improved. This effect is particularly evident when the vapor-deposited layer is an aluminum vapor-deposited layer.

[0031] Polyester polyols have two or more hydroxyl groups as functional groups in one molecule. Isocyanate compounds, on the other hand, have two or more isocyanate groups as functional groups in one molecule. Polyester polyols have, for example, a polyester structure or a polyester polyurethane structure as their main backbone.

[0032] A specific example of a two-component curing adhesive containing polyester polyol and isocyanate compounds is the PASLIM series sold by DIC Corporation.

[0033] The two-component curing adhesive may further contain a plate-like inorganic compound, a coupling agent, cyclodextrin and / or its derivatives, etc.

[0034] As polyester polyols having two or more hydroxyl groups in one molecule as functional groups, the following [Example 1] to [Example 3] can be used. [Example 1] Polyester polyol obtained by polycondensation of an ortho-oriented polycarboxylic acid or its anhydride with a polyhydric alcohol [Example 2] Polyester polyol having a glycerol skeleton [Example 3] Polyester polyol having an isocyanuric ring The following describes each type of polyester polyol.

[0035] The polyester polyol in the first example is a polycondensate obtained by polycondensing a polycarboxylic acid component containing at least one orthophthalic acid and its anhydride with a polyhydric alcohol component containing at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. In particular, polyester polyols in which orthophthalic acid and its anhydride are present in a proportion of 70 to 100% by mass relative to the total polycarboxylic acid components are preferred.

[0036] The polyester polyol according to the first example requires orthophthalic acid and its anhydride as polycarboxylic acid components, but other polycarboxylic acid components may be copolymerized to the extent that the effects of this embodiment are not impaired. Specifically, examples include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated bond-containing polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, anhydrides of these dicarboxylic acids, and ester-forming derivatives of these dicarboxylic acids; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred. Furthermore, two or more of the above-mentioned polycarboxylic acids may be used.

[0037] As an example of a polyester polyol related to the second example, a polyester polyol having a glycerol skeleton represented by general formula (1) can be mentioned. [ka] In general formula (1), R1, R2, and R3 are each independently H (hydrogen atom) or a group represented by the following general formula (2). [ka]

[0038] In formula (2), n represents an integer from 1 to 5, X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have substituents, and Y represents an alkylene group having 2 to 6 carbon atoms. However, at least one of R1, R2, and R3 represents a group represented by general formula (2).

[0039] In general formula (1), at least one of R1, R2, and R3 must be a group represented by general formula (2). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (2).

[0040] Furthermore, the compound may be a mixture of two or more compounds in which one of R1, R2, or R3 is a group represented by general formula (2), two of R1, R2, or R3 are groups represented by general formula (2), or all of R1, R2, and R3 are groups represented by general formula (2).

[0041] X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have substituents. If X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of such substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group.

[0042] In general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, methylpentylene group, and dimethylbutylene group. Among these, propylene and ethylene groups are preferred, with ethylene being the most preferred.

[0043] Polyester resin compounds having a glycerol skeleton represented by general formula (1) can be synthesized by reacting glycerol with an aromatic polycarboxylic acid in which the carboxylic acid is substituted in the ortho position or its anhydride, and a polyhydric alcohol component as essential components.

[0044] Examples of aromatic polycarboxylic acids or their anhydrides in which the carboxylic acid is substituted at the ortho position include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracenecarboxylic acid or its anhydride. These compounds may have substituents on any carbon atom of the aromatic ring. Examples of substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimide, carboxyl, carbamoyl, N-ethylcarbamoyl, phenyl, and naphthyl groups.

[0045] Furthermore, examples of polyhydric alcohol components include alkylenediols having 2 to 6 carbon atoms. For example, diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol can be cited.

[0046] The polyester polyol in the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3). [ka] In general formula (3), R1, R2, and R3 are each independently defined as "-(CH2) n1 -OH (where n1 represents an integer from 2 to 4), or represents the structure of general formula (4). [ka]

[0047] In general formula (4), n2 represents an integer from 2 to 4, n3 represents an integer from 1 to 5, X represents an arylene group selected from the group consisting of 1,2-phenylene, 1,2-naphthylene, 2,3-naphthylene, 2,3-anthraquinonediyl, and 2,3-anthracenediyl groups, which may have substituents, and Y represents an alkylene group having 2 to 6 carbon atoms. However, at least one of R1, R2, and R3 is a group represented by general formula (4).

[0048] In general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. n1 is preferably 2 or 3, with 2 being the most preferred.

[0049] In general formula (4), n² represents an integer between 2 and 4, and n³ represents an integer between 1 and 5. X represents an arylene group selected from the group consisting of a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 2,3-anthraquinonediyl group, and a 2,3-anthracenediyl group, which may have substituents.

[0050] If X is substituted by a substituent, it may be substituted by one or more substituents, and the substituent is bonded to any carbon atom on X that is different from the free radical. Examples of such substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group. The substituents of X are preferably hydroxyl, cyano, nitro, amino, phthalimide, carbamoyl, N-ethylcarbamoyl, and phenyl groups, with hydroxyl, phenoxy, cyano, nitro, phthalimide, and phenyl groups being the most preferred.

[0051] In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, methylpentylene group, and dimethylbutylene group. Among these, propylene and ethylene groups are preferred, with ethylene being the most preferred.

[0052] In general formula (3), at least one of R1, R2, and R3 is a group represented by general formula (4). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (4).

[0053] Furthermore, the compound may be a mixture of two or more compounds in which one of R1, R2, or R3 is a group represented by general formula (4), two of R1, R2, or R3 are groups represented by general formula (4), or all of R1, R2, and R3 are groups represented by general formula (4).

[0054] Polyester polyols having an isocyanuric ring, represented by general formula (3), can be synthesized by reacting a triol having an isocyanuric ring with an aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted in the ortho position, and a polyhydric alcohol component as essential components.

[0055] Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acids such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

[0056] Furthermore, examples of aromatic polycarboxylic acids or their anhydrides in which the carboxylic acid is substituted at the ortho position include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, naphthalene 1,2-dicarboxylic acid or its anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracenecarboxylic acid or its anhydride. These compounds may have substituents on any carbon atom of the aromatic ring.

[0057] Examples of substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group.

[0058] Furthermore, examples of polyhydric alcohol components include alkylenediols having 2 to 6 carbon atoms. Examples include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol. In particular, polyester polyol compounds having an isocyanuric ring are preferred when 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid is used as the triol compound having an isocyanuric ring, or when an aromatic polycarboxylic acid in which the carboxylic acid is substituted at the ortho position or orthophthalic anhydride is used as the anhydride thereof, and when ethylene glycol is used as the polyhydric alcohol, as these compounds exhibit particularly excellent oxygen barrier properties and adhesion.

[0059] The isocyanuric ring is highly polar and trifunctional, which can increase the overall polarity of the system and increase the crosslinking density. From this viewpoint, it is preferable to contain 5% by mass or more of the isocyanuric ring relative to the total solid content of the adhesive resin.

[0060] The oxidation of the polyester polyol is preferably 20 mg KOH / g or higher, and more preferably 50 mg KOH / g or higher. This allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved aroma retention for the contents.

[0061] Isocyanate compounds have two or more isocyanate groups in their molecule. Furthermore, the isocyanate compound may be aromatic or aliphatic, and may be a low-molecular-weight compound or a high-molecular-weight compound. Furthermore, the isocyanate compound may be a blocked isocyanate compound obtained by addition reaction using a known isocyanate blocking agent by a known and conventional method. In particular, polyisocyanate compounds having three or more isocyanate groups are preferred from the viewpoint of adhesion and retort resistance, and aromatic compounds are preferred from the viewpoint of oxygen barrier properties, water vapor barrier properties, and aroma retention.

[0062] Specific examples of isocyanate compounds include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, metaxylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds, as well as adducts, burettes, and allophanates obtained by reacting these isocyanate compounds with low molecular weight active hydrogen compounds or their alkylene oxide adducts, or high molecular weight active hydrogen compounds. Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine. Examples of molecular weight active hydrogen compounds include high molecular weight active hydrogen compounds of various polyester resins, polyether polyols, and polyamides.

[0063] The two-component curing adhesive used to form the adhesive layer may contain a phosphate-modified compound. This allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved fragrance retention for the contents. Phosphate-modified compounds are, for example, compounds represented by the following general formulas (5) or (6). [ka] In general formula (5), R1, R2, and R3 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, an optionally substituted phenyl group, and an alkyl group having 1 to 4 carbon atoms, but at least one of them is a hydrogen atom, and n represents an integer from 1 to 4. [ka] In the formula, R4 and R5 are groups selected from a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a (meth)acryloyl group, an optionally substituted phenyl group, and an alkyl group having 1 to 4 carbon atoms with a (meth)acryloyloxy group, where n is an integer from 1 to 4, x is an integer from 0 to 30, and y is an integer from 0 to 30, except when both x and y are 0.

[0064] More specifically, examples include phosphoric acid, pyrophosphate, triphosphate, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate, and one or more of these can be used.

[0065] The content of the phosphate-modified compound in the two-component curing adhesive is preferably 0.005% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less. By keeping the content of the phosphate-modified compound within the above numerical range, the oxygen barrier and water vapor barrier properties of the laminate can be better maintained, and the fragrance retention of the contents can be further improved.

[0066] The two-component curing adhesive used to form the adhesive layer preferably contains a plate-like inorganic compound, which allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved fragrance retention for the contents. Examples of plate-like inorganic compounds include kaolinite-serpentine clay minerals (haloysite, kaolinite, endelite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talc group minerals (pyrophyllite, talc, kerolite, etc.).

[0067] The two-component curing adhesive used to form the adhesive layer may contain a coupling agent. This allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved aroma retention for the contents. Examples of coupling agents include silane-based coupling agents, titanium-based coupling agents, or aluminum-based coupling agents represented by the following general formula (7). These coupling agents may be used individually or in combination of two or more types. [ka]

[0068] Examples of silane coupling agents include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β Examples include (aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene).

[0069] Examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(didodecyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl trioctainol titanate, isopropyl dimethacrylate isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, diisostearoylethylene titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and dicumylphenyl oxyacetate titanate.

[0070] Specific examples of aluminum-based coupling agents include, for example, acetalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkyl acetacetate aluminum oxide trimer.

[0071] The two-component curing adhesive used to form the adhesive layer preferably contains cyclodextrin and / or its derivatives. This allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved fragrance retention for the contents. Specifically, for example, cyclodextrins such as alkylated cyclodextrins, acetylated cyclodextrins, and hydroxyalkylated cyclodextrins, in which the hydrogen atom of the hydroxyl group of the glucose unit of a cyclodextrin is substituted with another functional group, can be used. Branched cyclic dextrins can also be used. Furthermore, the cyclodextrin skeleton in cyclodextrins and cyclodextrin derivatives may be any of the following: α-cyclodextrin consisting of 6 glucose units, β-cyclodextrin consisting of 7 glucose units, or γ-cyclodextrin consisting of 8 glucose units. These compounds may be used individually or in combination of two or more. Furthermore, these cyclodextrins and / or their derivatives may collectively be referred to as dextrin compounds from now on.

[0072] From the viewpoint of compatibility and dispersibility with resin compositions, it is preferable to use cyclodextrin derivatives as the cyclodextrin compound. From the viewpoint of the polarity of the various resins mentioned above, the degree of substitution is preferably in the range of 0.1 to 14 molecules / glucose, and more preferably in the range of 0.3 to 8 molecules / glucose.

[0073] Examples of alkylated cyclodextrins include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0074] Examples of acetylated cyclodextrins include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0075] Examples of hydroxyalkylated cyclodextrins include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0076] The thickness of the adhesive layer is preferably 0.5 μm to 6 μm, more preferably 0.8 μm to 5 μm, and even more preferably 1 μm to 4.5 μm. This allows for better maintenance of the oxygen barrier and water vapor barrier properties of the laminate, as well as improved aroma retention for the contents.

[0077] The adhesive layer can be formed by applying and drying it on a substrate or the like using conventionally known methods such as the direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fontein method, and transfer roll coating method.

[0078] (deposited layer) The laminate of the present invention comprises a vapor-deposited layer. Examples of vapor-deposited layers include metals such as aluminum, and inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. Among these, the aluminum vapor-deposited layer is preferred from the viewpoint of oxygen barrier properties, water vapor barrier properties, and aroma retention.

[0079] Conventional known methods can be used for forming the vapor-deposited layer, including, for example, physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition.

[0080] Furthermore, the thickness of the vapor-deposited layer is preferably between 1 nm and 140 nm, more preferably between 5 nm and 60 nm, and even more preferably between 5 nm and 40 nm. By keeping the thickness of the vapor-deposited layer within the above numerical range, the occurrence of cracks and other defects in the vapor-deposited layer can be prevented. When the vapor-deposited layer is an aluminum vapor-deposited layer, the thickness of the vapor-deposited layer is preferably 1 nm or more and 100 nm or less, more preferably 5 nm or more and 60 nm or less, and even more preferably . When the vapor-deposited layer is a silicon oxide or aluminum oxide vapor-deposited layer, the thickness of the vapor-deposited layer is preferably 1 nm or more and 140 nm or less, more preferably 5 nm or more and 30 nm or less, and even more preferably 5 nm or more and 20 nm or less.

[0081] Furthermore, for example, a composite film consisting of two or more deposited layers of different inorganic oxides can be formed and used by combining both physical vapor deposition and chemical vapor deposition methods. The vacuum level of the deposition chamber before oxygen introduction is 10 -2 ~10 -8 A bar of approximately mbar is preferred, and after oxygen introduction, 10 -1 ~10 -6 A pressure of approximately mbar is preferred. The amount of oxygen introduced will vary depending on the size of the deposition machine, etc. Inert gases such as argon, helium, and nitrogen may be used as carrier gases for the oxygen introduced, within reasonable limits. The film transport speed is preferably around 10 to 800 m / min, and particularly preferably around 50 to 600 m / min.

[0082] (Middle class) The laminate of the present invention may include an intermediate layer. The intermediate layer can be made of a resin material. Various resin materials can be used to make up the intermediate layer, for example, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polyolefin resins such as polyethylene resin and polypropylene resin, and polyamide resins such as nylon resin can be used. From the viewpoint of recyclability, it is preferable that the resin material is the same as the resin material of the base material. Furthermore, from the viewpoint of fragrance retention, it is preferable to use polyester resin, and more preferable to use polyethylene terephthalate resin. If the resin material making up the intermediate layer is not the same as the resin material of the base material, from the viewpoint of recyclability, it is preferable that the intermediate layer be 10% by mass or less of the total laminate.

[0083] The thickness of the intermediate layer is preferably 5 μm to 150 μm, more preferably 30 μm to 100 μm, and even more preferably 20 μm to 60 μm. This further improves the oxygen barrier properties, water vapor barrier properties, and aroma retention properties of the laminate.

[0084] The intermediate layer may be a resin film. Alternatively, it may be a single-layer film or a co-embossed film with two or more layers.

[0085] When the laminate of the present invention includes an intermediate layer, the substrate and the intermediate layer, or the intermediate layer and the sealant layer, may be bonded together via an adhesive. As the adhesive, for example, one-component or two-component curing or non-curing type vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others, solvent-based, aqueous-based, or emulsion-type adhesives can be used. As a two-component curing type adhesive, a cured product of a polyol and an isocyanate compound can be used. Furthermore, the adhesive used may be the same as the two-component curing type adhesive used in the adhesive layer.

[0086] When the laminate includes a vapor deposition layer of an inorganic oxide, it is preferable to provide a barrier coat layer between the base material layer and the adhesive layer. This can further improve the oxygen barrier property, water vapor barrier property, and fragrance retention property of the laminate.

[0087] In one embodiment, the barrier coat layer contains at least one resin composition such as a hydrolyzate of a metal alkoxide or a hydrolytic condensate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by the sol-gel method in the presence of a sol-gel method catalyst, water, an organic solvent, etc.

[0088] In one embodiment, the metal alkoxide is represented by the following general formula. R 1 n M(OR 2 ) m (However, in the formula, R 1 , R 2 each represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M.)

[0089] As the metal atom M, for example, silicon, zirconium, titanium, aluminum, etc. can be used. Also, examples of the organic group represented by R<> 1 and R<> 2 include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and i-butyl group.

[0090] Examples of the metal alkoxide satisfying the above general formula include tetramethoxysilane (Si(OCH3)4), tetraethoxysilane (Si(OC2H5)4), tetrapropoxysilane (Si(OC3H7)4), tetrabutoxysilane (Si(OC4H9)4), etc.

[0091] Also, it is preferable to use a silane coupling agent together with the above metal alkoxide. As silane coupling agents, known organic reactive group-containing organoalkoxysilanes can be used, but organoalkoxysilanes having an epoxy group are particularly preferred. Examples of organoalkoxysilanes having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0092] Two or more of the above-mentioned silane coupling agents may be used, and it is preferable to use the silane coupling agent in an amount of about 1 to 20 parts by mass per 100 parts by mass of the total amount of the above-mentioned alkoxides.

[0093] As water-soluble polymers, polyvinyl alcohol and ethylene-vinyl alcohol copolymers are preferred, and from the viewpoint of oxygen barrier properties, water vapor barrier properties, water resistance and weather resistance, as well as aroma retention, it is preferable to use these in combination.

[0094] The water-soluble polymer content in the barrier coat layer is preferably 5 to 500 parts by mass per 100 parts by mass of metal alkoxide. This further improves the strength, oxygen barrier properties, water vapor barrier properties, and aroma retention of the barrier coat layer.

[0095] The thickness of the barrier coat layer is preferably 0.01 μm to 100 μm, and more preferably 0.1 μm to 50 μm. This effectively prevents crack formation in the barrier coat layer while further improving its oxygen barrier properties, water vapor barrier properties, and aroma retention properties.

[0096] The barrier coat layer can be formed by applying a composition containing a top layer material onto a substrate using conventionally known methods such as roll coating with a gravure roll coater, spray coating, spin coating, dipping, brushing, barcode application, or applicator, and then polycondensing the composition by a sol-gel method. Suitable catalysts for the sol-gel process include acids or amine compounds. Suitable amine compounds include tertiary amines that are substantially insoluble in water and soluble in organic solvents, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. Among these, N,N-dimethylbenzylamine is preferred. The sol-gel catalyst is preferably used in an amount of 0.01 parts by mass to 1.0 part by mass per 100 parts by mass of metal alkoxide, and more preferably in an amount of 0.03 parts by mass to 0.3 parts by mass. This allows for a uniform thickness of the formed barrier coat layer and further improves the catalytic effect.

[0097] The above composition may further contain an acid. The acid is used as a catalyst for the sol-gel process, mainly as a catalyst for the hydrolysis of alkoxides and silane coupling agents. As the acid, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, as well as organic acids such as acetic acid and tartaric acid, can be used. The amount of acid used is preferably 0.001 moles or more and 0.05 moles or less relative to the total molar amount of the alkoxide and silane coupling agent's alkoxide component (e.g., silicate portion). This allows for a uniform thickness of the formed barrier coat layer and further improves the catalytic effect.

[0098] Furthermore, the above composition preferably contains water in an amount of 0.1 moles to 100 moles, more preferably 0.8 moles to 2 moles, per mole of the total molar amount of alkoxide. This improves the oxygen barrier and water vapor barrier properties of the barrier coat layer and allows the hydrolysis reaction to proceed rapidly.

[0099] Furthermore, the above composition may contain an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butanol, and the like.

[0100] The following describes one embodiment of a method for forming a barrier coat layer. First, a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent are mixed to prepare a composition. A polycondensation reaction gradually proceeds within this composition. Next, the composition is applied to the vapor-deposited layer and dried using the conventionally known method described above. This drying process further promotes the polycondensation reaction between the alkoxide and the water-soluble polymer (and the silane coupling agent, if the composition contains one), forming a layer of composite polymer. Finally, a barrier coat layer can be formed by heating the composition at a temperature of 20 to 250°C, preferably 50 to 220°C, for 1 second to 10 minutes.

[0101] (Sealant layer) The sealant layer may contain at least one resin material. From the viewpoint of recyclability, the resin material included in the sealant layer is preferably polyolefin and polyester, more preferably polyethylene, polypropylene and polyethylene terephthalate, and particularly preferably polypropylene. The sealant layer may be formed from an unstretched resin film or from melt extrusion of polypropylene.

[0102] Within the limits that do not impair the properties of the present invention, the sealant layer may contain additives such as antioxidants, antiblocking agents, lubricants, fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic particles, organic particles, mold release agents, and dispersants.

[0103] The sealant layer is preferably surface-treated. This improves adhesion with adjacent layers. The surface treatment method is not particularly limited and includes, for example, physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and chemical treatments such as oxidation treatment using chemicals.

[0104] The thickness of the sealant layer is preferably 5 μm to 150 μm, and more preferably 10 μm to 130 μm. This allows for improved processability and puncture resistance of the laminate while maintaining the heat-sealing properties of the sealant layer.

[0105] The laminate of the present invention has an oxygen permeability of 0.05 cc / m³ at 23°C and 90% relative humidity. 2 / day / atm or more 2.0cc / m 2 It is preferable that the pressure be less than or equal to / day / atm, and 0.05 cc / m³ 2 / day / atm or more 1.0cc / m 2 It is preferable that it be less than or equal to / day / atm. In this invention, the measurement of oxygen permeability is performed in accordance with JIS K 7126.

[0106] The laminate of the present invention has a water vapor transmission rate of 0.01 g / m² at 40°C and 90% relative humidity. 2 / day / atm or more 2.0g / m 2 It is preferable that the humidity is less than or equal to / day / atm, and 0.01 g / m³ 2 / day / atm or more 1.0g / m 2 It is preferable that it be less than or equal to / day / atm. In this invention, the measurement of oxygen permeability is performed in accordance with JIS K 7129.

[0107] (Method of manufacturing a laminate) The method for manufacturing the laminate according to the present invention is not particularly limited, and it can be manufactured using conventionally known methods such as melt extrusion lamination, dry lamination, and sand lamination.

[0108] The laminate according to the present invention can be subjected to secondary processing for the purpose of imparting chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, thermal functions, biocompatibility, and other surface functions. Examples of secondary processing include embossing, painting, bonding, printing, metallizing (plating, etc.), machining, and surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Furthermore, molded products can be manufactured by applying lamination (dry lamination or extrusion lamination), bag making, and other post-processing processes to the laminate according to the present invention.

[0109] (packaging bag) As described above, the laminate of the present invention has excellent aroma retention properties and can therefore be suitably used as an aroma-retaining packaging bag. An example of a packaging bag comprising the laminate of the present invention will be described below with reference to the figures.

[0110] Figure 4 is a front view showing an example of a packaging bag according to the present invention. The flat bag 20 shown in Figure 4 comprises body film (using the laminate described above) 21, 21'.

[0111] Next, the manufacturing method of the flat bag 20 will be explained with reference to Figure 4. First, prepare the body films 21 and 21' and position them so that their sealant layers face each other. Next, heat-seal the lower parts of the body films 21 and 21'. Then, use a side seal bar to heat-seal the heat-sealed parts on both sides of the body films 21 and 21'. Fill the contents through the opening at the top. Finally, heat-seal the top of the body films 21 and 21' to manufacture the flat bag 20. Here, the shaded area in Figure 4 represents the heat-sealed portion. Alternatively, the upper parts of the body films 21 and 21' may be heat-sealed first, and the lower parts of the body films 21 and 21' may be heat-sealed after the contents have been filled to manufacture the flat bag 20. Furthermore, the flat bag 20 may be formed from a single laminate of the body film 21 and body film 21'.

[0112] Figures 5 and 6 are a front perspective view and a rear perspective view showing another example of the packaging bag of the present invention. The pillow bag 30 shown in Figures 5 and 6 comprises a body film (using the laminate described above) 31.

[0113] Next, the manufacturing method of the pillow bag 30 will be described with reference to Figures 5 and 6. First, prepare the body film 31. Next, fold both the left and right ends of the body film 31 towards the center so that the sealant layer is on the inside, and heat seal the sealant layers together. Next, heat seal the bottom of the body film 31. Then, fill the contents through the opening at the top. Finally, heat seal the top of the body film 31 to manufacture the pillow bag 30. Here, the shaded areas in Figures 5 and 6 represent the heat-sealed areas. Alternatively, the pillow bag 30 may be manufactured by first heat-sealing the upper part of the body film 31, filling it with contents, and then heat-sealing the lower part of the body film 31.

[0114] Figure 7 is a front view showing another example of the packaging bag of the present invention. The stand pouch 40 shown in Figure 7 comprises body films (using the laminate described above) 41, 41' and a bottom film (which may be the same as or different from the body film) 42.

[0115] Next, the manufacturing method of the stand pouch 40 will be described with reference to Figure 7. First, prepare the body films 41 and 41' and arrange them so that their sealant layers face each other. Next, insert the bottom film 42 between the lower parts of the body films 41 and 41' so that it is folded back to form a gusset, and heat seal the body films 41 and 41' and the bottom film 42 using a boat-shaped heat sealing plate. Next, heat seal the heat-sealed portions on both sides of the body films 41 and 41' using a side seal bar. Then, fill the contents through the opening at the top. Finally, heat seal the top of the body films 41 and 41' to manufacture the stand pouch 40. Here, the shaded area in Figure 7 represents the heat-sealed portion. Alternatively, the stand pouch 40 may be manufactured by first heat-sealing the upper part of the body film 41, filling it with contents, and then heat-sealing the body film 31 and the bottom film 42 at the bottom. Furthermore, the stand pouch 40 may be formed from a single laminate of the body film 41 and body film 41'.

[0116] The contents filled into the packaging bag are not particularly limited as long as they have an aroma or flavor, and the contents may be liquids, powders, or gels. They may also be food products or non-food products.

[0117] The packaging bags of the present invention have excellent aroma retention properties for their contents. Therefore, they are preferably used for packaging foods where aroma and flavor are particularly important, such as coffee beans, instant coffee powder, black tea, green tea, confectionery such as fruit gummies and dried fruits, supplements with pungent or distinctive odors, or non-food items such as general merchandise. The packaging bags of the present invention can maintain the aroma and flavor of the contents for a long period of time. [Examples]

[0118] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0119] [Example 1] A biaxially oriented polypropylene resin film with a thickness of 25 μm was prepared as the substrate, and an image was formed on the biaxially oriented polypropylene resin film by gravure printing. The thickness of the printed layer was 1 μm.

[0120] Next, an unstretched polypropylene resin film (manufactured by Toray Processing Film Co., Ltd., product name: VM-CPP 2703, thickness: 30 μm) with a 50 nm thick aluminum vapor-deposited layer on one side was prepared. The printed side of the biaxially oriented polypropylene resin film and the vapor-deposited side of the unstretched polypropylene resin film were laminated together using a two-component curing adhesive (manufactured by DIC Corporation, product name: PASLIM VM NSRD011 / NSRD006) containing the polyester polyol and isocyanate compound described above. The thickness of the adhesive layer formed by this two-component curing adhesive was 2.5 μm.

[0121] The thickness of the laminate obtained in this way was 58.5 μm, and the proportion of polypropylene in the laminate was 93.4% by mass.

[0122] Next, the laminate obtained in this embodiment was used as the body film 41, 41' and the bottom film 42 to produce a stand pouch 40 as shown in Figure 7. The stand pouch 40 can be filled with the above-mentioned food or non-food items.

[0123] [Example 2] A biaxially oriented polypropylene resin film with a thickness of 25 μm was prepared as the substrate, and an image was formed on the biaxially oriented polypropylene resin film by gravure printing. The thickness of the printed layer was 1 μm.

[0124] Next, a polyethylene terephthalate (PET) resin film (manufactured by Toray Film Processing Co., Ltd., product name: VM-PET1312, thickness: 12 μm) with a 50 nm thick aluminum vapor-deposited layer on one side was prepared. The printed surface of the biaxially oriented polypropylene resin film and the vapor-deposited surface of the PET resin film were laminated together using a two-component curing adhesive (manufactured by DIC Corporation, product name: PASLIM VM NSRD011 / NSRD006) containing the polyester polyol and isocyanate compound described above. The thickness of the adhesive layer formed by this two-component curing adhesive was 2.5 μm.

[0125] Next, an unstretched polypropylene resin film was prepared, and the PET resin film surface of a PET resin film having an aluminum vapor deposition layer and the unstretched polypropylene resin film were laminated together using a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., product name: main component: RU-77T, curing agent: H-7). The thickness of the adhesive layer formed by this two-component curing adhesive was 3 μm.

[0126] The thickness of the laminate obtained in this way was 73.5 μm.

[0127] Next, the laminate obtained in this embodiment was used as the body film 41, 41' and the bottom film 42 to produce a stand pouch 40 as shown in Figure 7. The stand pouch 40 can be filled with the above-mentioned food or non-food items.

[0128] [Comparative Example 1] A laminate was prepared in the same manner as in Example 1, except that the printed surface of a biaxially oriented polypropylene resin film and the vapor-deposited surface of an unoriented polypropylene resin film were laminated using a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., product name: main component: RU-77T, curing agent: H-7). The thickness of the adhesive layer formed by the two-component curing adhesive was 3 μm.

[0129] Next, the laminate obtained in this comparative example was used as the body film 41, 41' and the bottom film 42 to produce a stand pouch 40 as shown in Figure 7.

[0130] [Comparative Example 2] A laminate was prepared in the same manner as in Example 2, except that the printed surface of a biaxially oriented polypropylene resin film and the vapor-deposited surface of a PET resin film were laminated using a two-component curing adhesive (manufactured by Rock Paint Co., Ltd., product name: main component: RU-77T, curing agent: H-7). The thickness of the adhesive layer formed by the two-component curing adhesive was 3 μm.

[0131] Next, the laminate obtained in this comparative example was used as the body film 41, 41' and the bottom film 42 to produce a stand pouch 40 as shown in Figure 7.

[0132] <<Oxygen Barrier Test>> The laminates obtained in the above examples and comparative examples were cut to A4 size, and the oxygen permeability (cc / m³) was measured using OXTRAN2 / 20 manufactured by MOCON, Inc., USA, in an environment of 23°C and 90% relative humidity. 2 The / day / atm (atm) was measured. The measurement results are summarized in Table 1.

[0133] <<Water vapor barrier property test>> The laminates obtained in the above examples and comparative examples were cut to A4 size, and the water vapor transmission rate (g / m³) was measured using PERMATRAN3 / 31 manufactured by MOCON, Inc., USA, in an environment of 40°C and 90% relative humidity. 2 The / day / atm (atm) was measured. The measurement results are summarized in Table 1.

[0134] <<Sensory Testing>> The laminates obtained in the above examples and comparative examples were cut to A5 size, then cut in half and heat-sealed at the ends to obtain three-sided bags. 30g of strawberry juice gummies were filled into these bags, sealed by heat sealing, and placed in a 60°C high-temperature chamber for two weeks. A sensory test was then conducted to check if the aroma of the fruit juice was leaking to the outside of the bags. The evaluation criteria for the sensory test were as follows. ○: No scent leakage. ×: There is a scent leak. The evaluation results are shown in Table 1.

[0135] [Table 1] [Explanation of symbols]

[0136] 10: Laminate 11: Base material 12: Adhesive layer 13: Vapor deposition layer 14: Sealant layer 15: Middle Class 20: Flat bag 21,21': Body material film 30: Pillow bag 31: Body material film 40: Stand-up pouch 41,41': Body material film 42: Bottom film

Claims

1. A laminate for an aroma-retaining packaging bag, comprising at least a substrate, an adhesive layer, a vapor deposition layer, and a sealant layer in this order, the substrate and the sealant contain the same resin material; Printing is applied to at least one surface of the substrate, A laminate for aroma-retaining packaging bags, characterized in that the adhesive layer is made of a cured product of a two-component curing adhesive containing a polyester polyol selected from the group consisting of polyester polyols having a glycerol skeleton and polyester polyols having an isocyanuric ring, and an isocyanate compound.

2. 2. The aroma-retaining packaging bag laminate according to claim 1, wherein the same resin material is polypropylene.

3. 3. The aroma-retaining packaging bag laminate according to claim 1, wherein the vapor-deposited layer is an aluminum vapor-deposited layer.

4. The aroma-retaining packaging bag laminate according to any one of claims 1 to 3, further comprising an intermediate layer between the vapor deposition layer and the sealant layer.

5. 5. The laminate for aroma-retaining packaging bags according to claim 4, wherein 90% by mass or more of the resins constituting the laminate are made of the same resin material.

6. The laminate for aroma-retaining packaging bags according to any one of claims 1 to 5, wherein the adhesive layer has a thickness of 0.5 µm or more and 6 µm or less.

7. The laminate for aroma-retaining packaging bags according to any one of claims 1 to 6, wherein the vapor-deposited layer has a thickness of 1 nm or more and 140 nm or less.

8. A fragrance-retaining packaging bag comprising the laminate according to any one of claims 1 to 7.

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