WO2023042767A1

WO2023042767A1 - Gas barrier layered body and packaging bag

Info

Publication number: WO2023042767A1
Application number: PCT/JP2022/033931
Authority: WO
Inventors: 裕美子小島; 純一神永; 良樹越山; 里佳石井; 寛之若林
Original assignee: 凸版印刷株式会社
Priority date: 2021-09-16
Filing date: 2022-09-09
Publication date: 2023-03-23
Also published as: JP2023043702A

Abstract

A gas barrier layered body according to the present disclosure comprises, in the following order, a paper base material, a vapor deposition layer, and a sealant layer, wherein, if the distance from the main surface of the vapor deposition layer on the paper base material side to the main surface of the paper base material on the opposite side to the vapor deposition layer is defined as X, and the distance from the main surface of the vapor deposition layer on the sealant layer side to the main surface of the sealant layer on the opposite side to the vapor deposition layer is defined as Y, then the value X/Y, obtained by dividing X by Y, is 0.6 to 2.5.

Description

Gas barrier laminate and packaging bag

The present disclosure relates to gas barrier laminates and packaging bags.

In many fields such as food, beverages, pharmaceuticals, and chemicals, packaging materials are used according to their contents. Packaging materials are required to have permeation-preventing properties (gas barrier properties) against water vapor and the like, which cause deterioration of contents.

In recent years, due to the heightened environmental awareness stemming from the problem of marine plastic litter, there is a growing momentum to eliminate plastic. From the viewpoint of reducing the amount of plastic material used, the use of paper instead of plastic material is being studied in various fields.

For example, Patent Document 1 discloses a packaging material having a paper substrate layer, a dry lamination adhesive layer, and a specific sealant layer laminated adjacently on the dry lamination adhesive layer.

JP 2012-250486 A

Paper has the characteristic of being easy to process because it has crease-retaining properties (also called dead-holding properties). However, according to the studies of the present inventors, when packaging bags with sharper folds (pillow packaging, three-sided seal packaging, and gusset packaging) are used, cracks occur in the layers and the gas barrier properties are lowered. It turned out that there was room for improvement.

Also, from the perspective of the Law for Promotion of Effective Utilization of Resources, it is required to reduce the amount of plastic material used in gas barrier laminates as well.

The present disclosure includes a gas barrier laminate that has crease retention characteristic of paper, has sufficient water vapor barrier properties even after being folded, and contributes to a reduction in the amount of plastic material used, and the same. Provide packaging bags.

A gas barrier laminate according to one aspect of the present disclosure includes a paper substrate, a vapor deposition layer, and a sealant layer in this order. Let X be the distance to the main surface on the side opposite to the vapor deposition layer, and let Y be the distance from the main surface of the vapor deposition layer on the sealant layer side to the main surface of the sealant layer on the opposite side to the adhesive layer. , X divided by Y is 0.6 to 2.5.

In one aspect, the gas barrier laminate may further include an anchor coat layer between the paper substrate and the vapor deposition layer.

The anchor coat layer may contain at least one of a polyvinyl alcohol-based resin and a polyolefin having a polar group.

The anchor coat layer contains the polyolefin having the polar group, and the polyolefin having the polar group is at least one selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester. may have

The anchor coat layer may contain the polyolefin having the polar group, and the polyolefin having the polar group may be a copolymer of acrylic acid ester and maleic anhydride.

The anchor coat layer may contain the polyolefin having the polar group, and the polyolefin having the polar group may be an ethylene-vinyl acetate copolymer.

The anchor coat layer may contain the polyolefin having the polar group, and the polyolefin having the polar group may be an ethylene-glycidyl methacrylate copolymer.

The anchor coat layer may contain the polyvinyl alcohol-based resin.

In one aspect, the gas barrier laminate may further comprise an adhesive layer between at least one of the vapor deposition layer and the sealant layer and between the paper substrate and the vapor deposition layer.

The adhesive layer is a cured product of a resin composition containing an epoxy resin and an epoxy resin curing agent, and the epoxy resin curing agent is meta-xylylenediamine or para-xylylenediamine, and is represented by the following formula (1). It may be a reaction product with an unsaturated carboxylic acid and/or a derivative thereof.

[In formula (1), R ¹ represents an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 1 to 8 carbon atoms, or an aryl group. ]

The adhesive layer may be a cured product of a resin composition containing a polyol having two or more hydroxyl groups in one molecule and an isocyanate compound having two or more isocyanate groups in one molecule.

The weight of the paper substrate may be 50% by mass or more based on the entire gas barrier laminate.

A packaging bag according to another aspect of the present disclosure includes the gas barrier laminate.

The packaging bag may have folds.

According to the present disclosure, a gas barrier laminate that has the characteristic crease retention of paper, has sufficient water vapor barrier properties even after being folded, and contributes to a reduction in the amount of plastic material used, and the same. A packaging bag is provided containing.

1 is a schematic cross-sectional view showing a gas barrier laminate according to an embodiment of the present disclosure; FIG. FIG. 4 is a schematic cross-sectional view showing a gas barrier laminate according to another embodiment of the present disclosure; FIG. 4 is a schematic cross-sectional view showing a gas barrier laminate according to still another embodiment of the present disclosure; 1 is a perspective view of a packaging bag according to an embodiment of the present disclosure; FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as the case may be. However, the present disclosure is not limited to the following embodiments.

<Gas barrier laminate>
FIG. 1 is a schematic cross-sectional view showing a gas barrier laminate according to one embodiment. A gas barrier laminate 10 according to one embodiment includes a paper substrate 1, an anchor coat layer 2, a deposition layer 3, an adhesive layer 4, and a sealant layer 5 in this order. The distance from the main surface of the vapor deposition layer 3 on the side of the paper substrate 1 to the main surface of the paper substrate 1 opposite to the vapor deposition layer 3 is X, and the distance from the main surface of the vapor deposition layer 3 on the sealant layer 5 side to the sealant layer 5 Assuming that the distance to the main surface on the side opposite to the deposited layer 3 is Y, the value X/Y obtained by dividing X by Y is 0.6 to 2.5.

When X/Y is 0.6 to 2.5, the gas barrier laminate 10 has excellent gas barrier properties. The inventors consider the mechanism by which such effects are exhibited as follows. That is, when the gas barrier laminate is folded, a compressive force is applied to the inner side of the fold, and a tensile force is applied to the outer side of the fold. Ordinarily, when the gas barrier laminate is bent, cracks occur in the deposited layer, which tends to crack due to compressive force or tensile force. However, by setting X/Y within the above range, the compressive force and the tensile force applied to the vapor deposition layer are offset, so that the vapor deposition layer tends to be difficult to crack. As a result, the gas barrier laminate 10 has excellent gas barrier properties.

X/Y is 0.6 or more, and the gas barrier property is further improved. Therefore, it is preferably 1.0 or more, more preferably 1.5 or more, and 2.5 or less. It is preferably 2.2 or less, more preferably 2.0 or less, because the properties are further improved.

[Paper substrate]
The paper base material 1 is not particularly limited, and may be appropriately selected according to the use of the packaging bag to which the gas barrier laminate 10 is applied. There is no particular limitation as long as the paper is mainly composed of plant-derived pulp. Specific examples of the paper substrate 1 include woodfree paper, special woodfree paper, coated paper, art paper, cast coated paper, imitation paper, kraft paper, and glassine paper. The thickness of the paper substrate 1 may be, for example, 30 μm or more and 100 μm or less, or 30 μm or more and 70 μm or less.

The paper substrate 1 may be provided with a coat layer at least on the side in contact with the anchor coat layer 2 described later. By providing a coat layer, it is possible to prevent the anchor coat layer from soaking into the paper, and it can also play the role of a filler that fills in the unevenness of the paper, making it possible to form the anchor coat layer uniformly without defects. can. As a result, the gas barrier laminate 10 is even more excellent in gas barrier properties. For the coating layer, for example, various copolymers such as styrene/butadiene, styrene/acrylic, ethylene/vinyl acetate, polyvinyl alcohol resin, cellulose resin, paraffin (WAX), etc. are used as binder resins. , and fillers such as clay, kaolin, calcium carbonate, talc, and mica.

The thickness of the coat layer may be, for example, 1-10 μm, or 3-8 μm.

The weight of the paper substrate 1 is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the entire gas barrier laminate. If the weight of paper is 50% by mass or more based on the entire gas barrier laminate, the amount of plastic material used can be sufficiently reduced, and the gas barrier laminate as a whole can be said to be made of paper and recycled. Excellent in nature.

[Anchor coat layer]
The anchor coat layer 2 is provided on the surface of the paper base material 1 to improve the adhesion between the paper base material 1 and the vapor deposition layer 3 described later and to improve the gas barrier properties of the gas barrier laminate. is. Although the anchor coat layer 2 is not particularly limited, it preferably contains a polyvinyl alcohol-based resin and a polyolefin having a polar group because it is more excellent in gas barrier properties (particularly, water vapor barrier properties). Since it is more excellent, it is preferable to contain a polyvinyl alcohol-based resin.

By including polyolefin having a polar group in the anchor coat layer 2, it is possible to form a dense film due to the crystallinity of polyolefin, and the water vapor barrier property is exhibited. Due to the crystallinity of the polyolefin, water vapor barrier properties are exhibited, and the presence of polar groups allows adhesion with the deposition layer 3 to be exhibited.

The polyolefin having a polar group may have at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group and a carboxylic acid ester.

Polyolefins having polar groups include copolymers of ethylene and propylene with unsaturated carboxylic acids (unsaturated compounds with carboxyl groups such as acrylic acid, methacrylic acid, and maleic anhydride), unsaturated carboxylic acid esters, and carboxylic acid esters. A salt obtained by neutralizing an acid with a basic compound may be used, or a copolymer obtained by copolymerizing vinyl acetate, an epoxy-based compound, a chlorine-based compound, a urethane-based compound, a polyamide-based compound, or the like may be used.

Specific examples of polyolefins having polar groups include copolymers of acrylic acid esters and maleic anhydride, ethylene-vinyl acetate copolymers, and ethylene-glycidyl methacrylate copolymers.

Polyvinyl alcohol resins include, for example, completely saponified polyvinyl alcohol resins, partially saponified polyvinyl alcohol resins, modified polyvinyl alcohol resins, ethylene-vinyl alcohol copolymer resins, and the like. Moreover, the degree of polymerization of the polyvinyl alcohol resin is preferably 300 or more and 1700 or less. If the degree of polymerization is 300 or more, the gas barrier property and bending resistance of the gas barrier laminate will be good. get better.

When the anchor coat layer 2 contains a polyvinyl alcohol-based resin, it is excellent in flexibility and can suppress cracking of the vapor deposition layer described later after bending (after bending), thereby suppressing deterioration of the gas barrier properties, and the vapor deposition layer and the anchor coat layer 2 can be improved.

The anchor coat layer 2 may contain other components in addition to the above polyolefin and polyvinyl alcohol resin. Other components include, for example, polyolefins other than the above polyolefins, polyacrylics, polyesters, polyurethanes, polyethyleneimine, polylactic acid, polyamides, starch and its derivatives, and resins such as cellulose derivatives, silane coupling agents, organic titanates, Additives such as glycerin, glycols, casein and waxes may be mentioned.

The total content of polyolefin and polyvinyl alcohol resin in the anchor coat layer 2 may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass. It's okay.

The thickness of the anchor coat layer 2 may be, for example, 1 μm or more, 2 μm or more, 20 μm or less, 10 μm or less, or 5 μm or less. If the thickness of the anchor coat layer 2 is 1 μm or more, the unevenness of the paper substrate 1 can be efficiently filled, and the vapor deposition layer 3 described later can be uniformly laminated. Moreover, if the thickness of the anchor coat layer 2 is 20 μm or less, the deposition layer 3 can be uniformly laminated while suppressing the cost.

Examples of the solvent contained in the coating liquid of the anchor coat layer 2 include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethylsulfoxide, dimethylformamide, and dimethylacetamide. , toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate. These solvents may be used singly or in combination of two or more. Among these, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred from the viewpoint of properties. Moreover, from the viewpoint of the environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferable.

The method of providing the anchor coat layer 2 is not particularly limited. When the anchor coat layer 2 contains at least one of the polyolefin and polyvinyl alcohol resins described above, a coating liquid containing at least one of the polyolefin and polyvinyl alcohol resins described above and a solvent is applied onto the paper substrate. It can be obtained by drying. From the viewpoint of preventing blocking, the polyolefin in the coating liquid preferably has a large particle size so that the contact area becomes small. Although not particularly limited, the particle size may specifically be 1 nm or more, 0.1 μm or more, or 1 μm or less, 0.7 μm or less, or 0.5 μm or less.

[Vapor deposition layer]
The deposited layer 3 is a layer deposited with a metal or an inorganic compound. The deposited layer may be obtained by vapor deposition of aluminum, or may contain aluminum oxide (AlO _x ), silicon oxide (SiO _x ), or the like.

The thickness of the vapor deposition layer 3 may be appropriately set depending on the intended use, but may preferably be 10 nm or more, 30 nm or more, 50 nm or more, and may be 300 nm or less, 100 nm or less, and 80 nm or less. When the thickness of the deposition layer 3 is 10 nm or more, the continuity of the deposition layer 3 can be easily made sufficient, and when the thickness is 300 nm or less, the occurrence of curling and cracking can be sufficiently suppressed, and sufficient gas barrier performance and flexibility can be obtained. easy to achieve.

From the viewpoint of oxygen gas barrier performance and film uniformity, it is preferable to form the deposited layer 3 by a vacuum film forming means. Film formation means include known methods such as a vacuum deposition method, a sputtering method, and a chemical vapor deposition method (CVD method), but the vacuum deposition method is preferred because of its high film formation speed and high productivity. Among vacuum evaporation methods, electron beam heating is particularly effective because the film formation rate can be easily controlled by adjusting the irradiation area and electron beam current, and the temperature of the vapor deposition material can be raised and lowered in a short period of time. be.

[Adhesive layer]
The adhesive layer 4 is provided on the surface of the vapor deposition layer 3 so as to be in contact with the vapor deposition layer 3 . As the adhesive layer 4, various materials can be used as long as they adhere the deposition layer 3 and the sealant layer 5 together. is mentioned.

<Urethane adhesive>
A urethane-based adhesive is a resin composition containing a polyol having two or more hydroxyl groups in one molecule and an isocyanate compound having two or more isocyanate groups in one molecule. A urethane bond is generated by curing the urethane adhesive. The urethane-based adhesive is preferably of a two-liquid curing type.

The urethane-based adhesive may have gas barrier properties. Methods for imparting gas barrier properties to urethane-based adhesives include, for example, a method of using a polyol having a skeleton having gas barrier properties, a method of incorporating a phosphoric acid-modified compound into the resin composition, and a method of adding a plate-like inorganic compound to the resin composition. A method of containing a compound is included. These methods can be used singly or in combination of two or more methods.

As a polyol having a skeleton with barrier properties, it is preferable that the main skeleton is polyester or polyester polyurethane, and the polyester contains a structure derived from an ortho-oriented aromatic dicarboxylic acid or its anhydride. The polyester portion of the main skeleton may be obtained by a polycondensation reaction between a polyhydric carboxylic acid and a polyhydric alcohol.

Examples of polyvalent carboxylic acids include aliphatic polyvalent carboxylic acids and aromatic polyvalent carboxylic acids. Aliphatic polycarboxylic acids include, for example, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.

Examples of aromatic polycarboxylic acids include orthophthalic acid, terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,2-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid. 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 and anhydrides of these dicarboxylic acids, and polybasic acids such as p-hydroxybenzoic acid and p-(2-hydroxyethoxy)benzoic acid. Polyvalent carboxylic acid can be used alone or in combination of two or more.

As the polyvalent carboxylic acid, an ortho-oriented aromatic dicarboxylic acid or its anhydride is preferable. The content of the ortho-oriented aromatic dicarboxylic acid or its anhydride is preferably 70 to 100% by mass based on the total amount of the polyvalent carboxylic acid component constituting the polyester.

Examples of ortho-oriented aromatic dicarboxylic acids include orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, and anhydrides of these dicarboxylic acids.

Polyhydric alcohols include aliphatic polyhydric alcohols and aromatic polyhydric phenols. Examples of aliphatic polyhydric alcohols include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexane. Diols, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol and tripropylene glycol.

Aromatic polyhydric phenols include, for example, hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, ethylene oxide extensions thereof, and hydrogenated alicyclics.

The isocyanate compound may be aromatic having an aromatic ring, may be aliphatic having no aromatic ring, may be a low-molecular-weight compound or a high-molecular-weight compound, and may be a diisocyanate having two isocyanate groups. compound or three or more polyisocyanate compounds. The isocyanate compound may be a blocked isocyanate compound obtained by addition reaction of an isocyanate blocking agent.

From the viewpoint of adhesiveness of the adhesive layer 4, the isocyanate compound is preferably a polyisocyanate compound. Since the isocyanate compound imparts oxygen barrier properties to the adhesive layer 4, those having an aromatic ring are preferred, and an isocyanate compound containing a meta-xylene skeleton is particularly preferred.

Examples of isocyanate compounds include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, meta-xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. be done. These isocyanate compounds include, for example, ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, Low-molecular-weight active hydrogen compounds such as monoethanolamine, diethanolamine, triethanolamine, and meta-xylylenediamine, their alkylene oxide adducts, various polyester resins, polyether polyols, high-molecular-weight active hydrogen compounds such as polyamides, and isocyanate compounds It may be an adduct, burette, or allophanate obtained by reacting with.

<Epoxy adhesive>
An epoxy adhesive is a resin composition containing an epoxy resin and an epoxy resin curing agent.

Epoxy resins may have saturated or unsaturated bonds, and may be aliphatic compounds, alicyclic compounds, aromatic compounds, or heterocyclic compounds. The epoxy resin is preferably an epoxy resin containing an aromatic ring or an alicyclic structure in its molecule in order to exhibit higher gas barrier properties.

Examples of epoxy resins include epoxy resins having glycidylamino groups derived from metaxylylenediamine, epoxy resins having glycidylamino groups derived from 1,3-bis(aminomethyl)cyclohexane, and epoxy resins derived from diaminodiphenylmethane. epoxy resins having glycidylamino groups, epoxy resins having glycidylamino groups and/or glycidyloxy groups derived from para-aminophenol, epoxy resins having glycidyloxy groups derived from bisphenol A, glycidyl derived from bisphenol F Epoxy resins having an oxy group, epoxy resins having a glycidyloxy group derived from phenol novolak, and epoxy resins having a glycidyloxy group derived from resorcinol can be mentioned. You may use an epoxy resin individually by 1 type or in combination of 2 or more types. From the viewpoint of gas barrier properties, the epoxy resin is preferably an epoxy resin having a glycidylamino group derived from metaxylylenediamine and an epoxy resin having a glycidyloxy group derived from bisphenol F. Epoxy resins having a glycidylamino group are more preferred.

The epoxy resin curing agent may be a reaction product of meta-xylylenediamine or para-xylylenediamine and an unsaturated carboxylic acid represented by the following formula (1) and/or its derivative.

The gas barrier property is further improved by using meta-xylylenediamine or para-xylylenediamine as the precursor of the epoxy resin curing agent. Meta-xylylenediamine or para-xylylenediamine is preferably meta-xylylenediamine from the viewpoint of gas barrier properties. Meta-xylylenediamine or para-xylylenediamine may be used alone or in combination of two or more.

By using the unsaturated carboxylic acid represented by the above formula (1) and/or its derivative as a precursor of the epoxy resin curing agent, good adhesiveness is exhibited. The unsaturated carboxylic acids represented by the above formula (1) and/or derivatives thereof include crotonic acid, 2-pentenoic acid, 2-hexenoic acid, 4-methyl-2-pentenoic acid, 2-heptenoic acid, 4-methyl -2-hexenoic acid, 5-methyl-2-hexenoic acid, 4,4-dimethyl-2-pentenoic acid, 4-phenyl-2-butenoic acid, cinnamic acid, o-methylcinnamic acid, m-methylcinnamic acid, Unsaturated carboxylic acids such as p-methylcinnamic acid, 2-octenoic acid, 2-nonenoic acid, 2-decenoic acid, 2-undecenoic acid, and derivatives thereof (e.g., esters, amides, acid anhydrides, acid chlorides, etc.) ), but are not particularly limited to these. The unsaturated carboxylic acid represented by formula (1) and/or its derivative may be used singly or in combination of two or more.

The unsaturated carboxylic acid represented by the above formula (1) and/or its derivative further improves the gas barrier property and adhesiveness, so that R ¹ in the above formula (1) is a hydrocarbon group having 1 to 3 carbon atoms or a phenyl At least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof is preferred, at least one selected from the group consisting of crotonic acid and crotonic acid derivatives is more preferred, and the group consisting of crotonic acid and crotonic acid esters At least one selected from is more preferable. As the crotonate, an alkyl ester having 1 to 3 carbon atoms is more preferred, and methyl crotonate is even more preferred.

The adhesive layer 4 may be formed using a one-component curing or two-component curing adhesive (dry lamination method), or may be formed using a non-solvent adhesive (non-solvent dry lamination method ), or may be formed by extruding a molten resin onto the surface of the deposition layer 3 (extrusion lamination method).

From the viewpoint of improving the adhesiveness of the adhesive layer 4, the thickness of the adhesive layer 4 is preferably 0.01 μm or more, more preferably 3 μm or more, so that the amount of plastic material used can be further reduced. Therefore, it is preferably 10 μm or less.

[Sealant layer]
The sealant layer 5 is provided on the surface of the adhesive layer 4 so as to be in contact with the adhesive layer 4 . Materials for the sealant layer 5 include thermoplastic resins such as polyolefin resins, polyester resins, and biodegradable resins such as polylactic acid and polybutylene succinate, and polyolefin resins are generally used. Specifically, polyolefin resins include low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), linear low-density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α Olefin copolymers, ethylene-based resins such as ethylene-(meth)acrylic acid copolymers, homopolypropylene resins (PP), propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-α olefin copolymers Polypropylene-based resins such as coalesced, or mixtures thereof and the like can be used.

The thickness of the sealant layer is preferably 5 μm or more because the seal strength is improved, and is preferably 50 μm or less because the amount of plastic material used is further reduced.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments. For example, gas barrier laminates according to other embodiments may include an adhesive layer instead of the anchor coat layer. Further, the gas barrier laminate according to another embodiment may have a film substrate between the vapor deposition layer and the adhesive layer. The gas barrier laminate 30 shown in FIG. , in this order.

Examples of materials for the film base layer include polyethylene terephthalate (PET) film.

Further, in the gas barrier laminate according to still another embodiment, the adhesive layer 4 may not be provided between the vapor deposition layer 3 and the sealant layer 5. A gas barrier laminate 40 shown in FIG. 3 includes a paper substrate 1, an adhesive layer 4, a deposition layer 3, and a sealant layer 5 in this order.

<Packaging bag>
FIG. 4 is a perspective view showing a gusset bag 20 made of the gas barrier laminate 10. FIG. A packaging bag is manufactured by sealing the upper opening of the gusset bag 20 . The gusset bag 20 has portions (folded portions B1, B2) where the gas barrier laminate 10 is folded. The bent portion B1 is a portion where the gas barrier laminate 10 is valley-folded when viewed from the innermost layer side, while the bent portion B2 is a portion where the gas barrier laminate 10 is mountain-folded when viewed from the innermost layer side.

The packaging bag may be formed into a bag shape by folding one sheet of the gas barrier laminate in two so that the sealant layers 5 face each other, then appropriately folding it into a desired shape and heat-sealing it. Alternatively, two gas barrier laminates may be stacked such that the sealant layers 5 face each other, and then heat-sealed to form a bag shape.

In the packaging bag according to this embodiment, the heat seal strength may be 2N or more, or 10N or more. Although the upper limit of the heat seal strength is not particularly limited, it may be 20 N or less, for example.

The packaging bag can contain contents such as food and medicine. In particular, it is suitable for storing sweets and the like as food. The packaging bag according to this embodiment can maintain a high gas barrier property even if it has a shape having a folded portion.

In the present embodiment, a gusset bag is given as an example of a packaging bag, but the gas barrier laminate according to the present embodiment may be used to produce, for example, a pillow bag, a three-sided seal bag, or a standing pouch. .

The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

<Fabrication of gas barrier laminate>
(Example 1)
A coating solution containing a salt of a carboxyl group (trade name: Chemipearl ^S100 , An ionomer type, particle size: <0.1 μm, solvent: water, IPA, manufactured by Mitsui Chemicals) was applied with a bar coater and dried in an oven to form an anchor coat layer (thickness: 3 μm). AL vapor deposition was performed on the anchor coat layer to form an AL vapor deposition layer (thickness: 50 nm). On the deposition layer, a linear low-density polyethylene (LLDPE) film (trade name: TUX-MCS, manufactured by Mitsui Chemicals Tohcello, thickness: 30 μm) as a sealant layer is applied with an adhesive (trade name: Takelac A525/Takenate). A52, urethane-based two-liquid type, manufactured by Mitsui Chemicals, Inc.) was used for dry lamination to obtain a gas barrier laminate. The thickness of the adhesive layer was 5 μm. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 2)
Bondine HX-8290 (trade name, manufactured by Arkema), which is a copolymer of acrylic acid ester and maleic anhydride, was neutralized with triethylamine in a water/IPA mixed solvent to prepare a polyolefin aqueous dispersion. Part or all of maleic anhydride is ring-opened in an aqueous solvent to form a carboxylic acid, but after drying, part or all of it is again dehydrated and cyclized. A gas barrier laminate was obtained in the same manner as in Example 1, except that the anchor coat layer was formed using a polyolefin aqueous dispersion instead of the coating liquid containing a salt of a carboxyl group. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 3)
The procedure was the same as in Example 1, except that an ethylene-glycidyl methacrylate copolymer (trade name: Sepolsion G515, manufactured by Sumitomo Seika Chemical Co., Ltd.) was used instead of the coating solution containing a carboxyl group salt to form the anchor coat layer. to obtain a gas barrier laminate. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 4)
Except that the anchor coat layer was formed using a coating liquid made of ethylene-vinyl acetate copolymer (trade name: Chemipearl V300, manufactured by Mitsui Chemicals, Inc.) instead of the coating liquid containing a carboxyl group salt. A gas barrier laminate was obtained in the same manner as in Example 1. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 5)
A gas barrier laminate was obtained in the same manner as in Example 1, except that silica was used instead of AL for the deposited layer. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 6)
Except that the adhesive layer was formed using Maxieve M-100/C-93 (trade name, manufactured by Mitsubishi Gas Chemical Company, Inc., an epoxy adhesive with gas barrier properties) instead of Takelac A525/Takenate A52. A gas barrier laminate was obtained in the same manner as in Example 1. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 7)
In the same manner as in Example 1, except that the adhesive layer was formed using PASLIM VM001/108CP (trade name, manufactured by DIC Corporation, a urethane-based adhesive having gas barrier properties) instead of Takelac A525/Takenate A52. A gas barrier laminate was obtained. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 8)
An anchor coat layer was formed on the surface of the paper in the same manner as in Example 1, and an AL deposition layer was formed on the anchor coat layer. On the deposition layer, a linear low-density polyethylene (LLDPE) film (trade name: TUX-MCS, manufactured by Mitsui Chemicals Tohcello, Inc., thickness: 30 μm) as a sealant layer is applied with NSRD011/NSRD006 (trade name, DIC Corporation). A gas barrier laminate was obtained by non-solvent dry lamination using a urethane adhesive having gas barrier properties. The thickness of the adhesive layer was 5 μm. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 9)
An anchor coat layer was formed on the surface of the paper in the same manner as in Example 1, and an AL deposition layer was formed on the anchor coat layer. A-3210/A-3075 (trade name, manufactured by Mitsui Chemicals, Inc.) is extruded on the vapor deposition layer, and the vapor deposition layer and a low-density polyethylene resin (LDPE) film as a sealant layer (trade name: Novatic LC-600A, Japan Polyethylene Co., Ltd.) was laminated through A-3210/A-3075 to obtain a gas barrier laminate. The thickness of the adhesive layer was 5 μm. The weight of paper in the gas barrier laminate was 57% by mass.

(Example 10)
Gas barrier lamination was carried out in the same manner as in Example 1, except that the anchor coat layer was formed using a polyvinyl alcohol-based resin (degree of saponification: 98%, degree of polymerization: 500) instead of the coating liquid containing a salt of a carboxyl group. got a body The weight of paper in the gas barrier laminate was 53% by mass.

(Example 11)
Gas barrier lamination was carried out in the same manner as in Example 1, except that the anchor coat layer was formed using a polyvinyl alcohol-based resin (degree of saponification: 88%, degree of polymerization: 500) instead of the coating liquid containing a salt of a carboxyl group. got a body The weight of paper in the gas barrier laminate was 53% by mass.

(Example 12)
Gas barrier in the same manner as in Example 1, except that a modified polyvinyl alcohol-based resin (trade name: Exeval AQ4104, manufactured by Kuraray Co., Ltd.) was used instead of the coating liquid containing a carboxyl group salt to form the anchor coat layer. A laminate was obtained. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 13)
A gas barrier laminate was obtained in the same manner as in Example 10, except that silica was used instead of AL for the deposited layer. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 14)
A gas barrier laminate was obtained in the same manner as in Example 10, except that EA-N370A/B (trade name, manufactured by Toyo Ink Co., Ltd.) was used instead of Takelac A525/Takenate A52 to form the adhesive layer. The weight of paper in the gas barrier laminate was 53% by mass.

(Example 15)
An anchor coat layer was formed on the surface of the paper in the same manner as in Example 10, and an AL deposition layer was formed on the anchor coat layer. A-3210/A-3075 (trade name, manufactured by Mitsui Chemicals, Inc.) is extruded on the vapor deposition layer, and the vapor deposition layer and a low-density polyethylene resin (LDPE) film as a sealant layer (trade name: Novatic LC-600A, Japan Polyethylene Co., Ltd.) was laminated through A-3210/A-3075 to obtain a gas barrier laminate. The thickness of the adhesive layer was 0.2 μm. The weight of paper in the gas barrier laminate was 57% by mass.

(Example 16)
Paper (clay-coated paper, thickness of paper: 50 μm, thickness of clay-coating layer: 5 μm, basis weight: 55 g/m ² ) and polyethylene terephthalate (PET) film having silica deposition layer provided on one surface and prepared. An adhesive (trade name: Takelac A525/Takenate A52, urethane-based two-liquid type, manufactured by Mitsui Chemicals, Inc.) is applied to the surface of the paper, and the paper and the surface not provided with the vapor deposition layer of the PET film are bonded. pasted together. On the deposition layer, a linear low-density polyethylene (LLDPE) film (trade name: TUX-MCS, manufactured by Mitsui Chemicals Tohcello, thickness: 30 μm) as a sealant layer is applied with an adhesive (trade name: Takelac A525/Takenate). A52, urethane-based two-liquid type, manufactured by Mitsui Chemicals, Inc.) was used for dry lamination to obtain a gas barrier laminate. The thickness of the two adhesive layers was 5 μm. The weight of paper in the gas barrier laminate was 36% by mass.

(Example 17)
Paper (clay-coated paper, thickness of paper: 50 μm, thickness of clay-coating layer: 5 μm, basis weight: 55 g/m ² ) and linear low-density polyethylene with a silica deposition layer provided on one surface A resin (LLDPE) film (trade name: TUX-MCS, manufactured by Mitsui Chemicals Tohcello, Inc., thickness: 30 μm) was prepared. An adhesive (trade name: Takelac A525 / Takenate A52, urethane-based two-liquid type, manufactured by Mitsui Chemicals, Inc.) is applied to the surface of the paper, and the paper and the surface on which the vapor deposition layer of the sealant layer is provided. pasted together. The thickness of the adhesive layer was 5 μm. The weight of paper in the gas barrier laminate was 58% by mass.

<Measurement of water vapor permeability>
The water vapor permeability of the gas barrier laminates according to Examples and Comparative Examples was measured by the MOCON method. The measurement conditions were a temperature of 40° C. and a relative humidity of 90%. While rolling a roller of 600 g at a speed of 300 mm/min, the gas barrier laminate was creased, and the water vapor transmission rate of the gas barrier laminate after opening was similarly measured. "Outward folding" in Tables 1 to 5 indicates the gas barrier laminate after the gas barrier laminate is valley-folded when viewed from the paper substrate side. The results are shown in Tables 1 to 5 in the unit [g/m ² ·day].

<Measurement of oxygen permeability>
The oxygen permeability of the gas barrier laminates according to Examples and Comparative Examples was measured according to JIS K7126, Method B (isobaric method). As a measuring device, OXTRAN 2/20 manufactured by MOCON was used, and the measurement was performed at a temperature of 30°C and a relative humidity of 70%. Tables 1 to 5 show the results in units [cc/m ² /d/atm].

<Measurement of heat seal strength>
Two gas-barrier laminates were stacked so that the sealant layers faced each other, and heat-sealed with a heat sealer under the conditions of 120°C, 0.2 MPa, and 1 second. The maximum load when T-shaped peeling was performed at a peeling speed of 300 mm/min was measured. Tables 1 to 5 show the results in units [N/15 mm].

DESCRIPTION OF SYMBOLS 1... Paper base material, 2... Anchor coat layer, 3... Vapor deposition layer, 4... Adhesive layer, 5... Sealant layer, 10, 30, 40... Gas barrier laminate, 12... Film base layer, 20... Gusset bag, B1, B2... Bent parts.

Claims

a paper substrate;
a vapor deposition layer;
a sealant layer;
in this order,
The distance from the main surface of the vapor deposition layer on the paper substrate side to the main surface of the paper substrate opposite to the vapor deposition layer is X, and the sealant layer from the main surface of the vapor deposition layer on the sealant layer side. A gas barrier laminate, wherein a value X/Y obtained by dividing X by Y is 0.6 to 2.5, where Y is the distance to the main surface on the opposite side of the vapor-deposited layer.
The gas barrier laminate according to claim 1, further comprising an anchor coat layer between the paper substrate and the vapor deposition layer.
The gas barrier laminate according to claim 2, wherein the anchor coat layer contains at least one of a polyvinyl alcohol-based resin and a polyolefin having a polar group.
The anchor coat layer contains the polyolefin having the polar group,
4. The gas barrier laminate according to claim 3, wherein the polyolefin having a polar group has at least one selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group, and a carboxylic acid ester.
The anchor coat layer contains the polyolefin having the polar group,
4. The gas barrier laminate according to claim 3, wherein the polyolefin having a polar group is a copolymer of acrylic acid ester and maleic anhydride.
The anchor coat layer contains the polyolefin having the polar group,
4. The gas barrier laminate according to claim 3, wherein the polyolefin having a polar group is an ethylene-vinyl acetate copolymer.
The anchor coat layer contains the polyolefin having the polar group,
4. The gas barrier laminate according to claim 3, wherein the polyolefin having a polar group is an ethylene-glycidyl methacrylate copolymer.
The gas barrier laminate according to claim 3, wherein the anchor coat layer contains the polyvinyl alcohol-based resin.
The gas barrier laminate according to any one of claims 1 to 8, further comprising an adhesive layer between at least one of the vapor deposition layer and the sealant layer and between the paper substrate and the vapor deposition layer. body.
The adhesive layer is a cured product of a resin composition containing an epoxy resin and an epoxy resin curing agent,
10. The gas barrier according to claim 9, wherein the epoxy resin curing agent is a reaction product of meta-xylylenediamine or para-xylylenediamine and an unsaturated carboxylic acid represented by the following formula (1) and/or a derivative thereof. laminate.

[In formula (1), R 1 represents an alkyl group having 1 to 8 carbon atoms, an aralkyl group having 1 to 8 carbon atoms, or an aryl group. ]
The adhesive layer according to claim 9, which is a cured product of a resin composition containing a polyol having two or more hydroxyl groups in one molecule and an isocyanate compound having two or more isocyanate groups in one molecule. gas barrier laminate.
The gas barrier laminate according to any one of claims 1 to 11, wherein the paper base material has a weight of 50% by mass or more based on the entire gas barrier laminate.
A packaging bag containing the gas barrier laminate according to any one of claims 1 to 12.
The packaging bag according to claim 13, which has a folded portion.