JP2020100024A - Gas barrier laminate and packaging medium - Google Patents

Abstract

To provide a laminate having metallic luster, superior to microwave oven suitability and gas barrier and suitable for a packaging medium, and a packaging medium using the laminate.SOLUTION: A laminate includes a base material, a gas barrier adhesive layer, a glossy layer and a sealant layer. The gas barrier adhesive layer is arranged between the base material and the sealant layer. The glossy layer is arranged close to the gas barrier adhesive layer between the base material and the gas barrier adhesive layer. The glossy layer contains resin and a metallic particle. The content of the metallic particle in the glossy layer is 4.7-47.2 mass%. A packaging medium is provided by using the laminate.SELECTED DRAWING: None

Description

The present invention relates to a gas barrier laminate and a packaging material obtained by using the gas barrier laminate.

The packaging materials for foods and beverages have properties such as retort resistance, oil resistance, and heat resistance necessary for the contents and their processing, transparency intended to confirm the contents, and metallic luster for aesthetics. It is composed of a laminated body in which various base materials selected according to the purpose from the appearance characteristics are laminated. As such a packaging material, a packaging material using a laminate in which an aluminum foil and a resin film are bonded together is known. The aluminum foil is used for the purpose of giving the packaging material a metallic luster appearance and enhancing the gas barrier property of the packaging material.

In a laminate in which an aluminum foil and a resin film are bonded together, the aluminum foil is usually exposed in the cross section (end of the laminate). When the contents together with the packaging material using such a laminated body are heated in a microwave oven, sparks may occur and the packaging material may shrink or melt. Therefore, when heating the contents packaged with the packaging material using the laminate including the aluminum foil in the microwave oven, it was necessary to transfer the contents to another container. There is known a packaging material in which the cross section of the aluminum foil is not exposed so as to save such troubles and prevent the generation of sparks and heating in a microwave oven (Patent Document 1). Alternatively, it is known that the deterioration of the packaging material due to the occurrence of sparks is prevented by using a laminate provided with a gloss layer containing a specific amount of aluminum paste instead of the aluminum foil as the packaging material (Patent Document 2). ..

JP, 2006-341423, A JP, 2003-13032, A

However, in the method described in Patent Document 1, electromagnetic waves are blocked by the aluminum foil. Therefore, in order to heat the contents in a microwave oven, it is necessary to provide a part of the packaging material where the aluminum foil does not exist. , There is less freedom in designing packaging materials. Further, if the irradiation of the electromagnetic wave is only from a part, the heating efficiency of the food is low and the heating temperature is likely to be uneven, and the uneven boiling of the food containing the liquid may cause a bumping phenomenon. Since the aluminum foil is not present in a part of the packaging material, the gas barrier property of the packaging material is low and the period during which the contents can be stored is shortened.

The packaging material described in Patent Document 2 has a low gas barrier property, and the period during which the contents can be stored is shortened as compared with the packaging material using the laminate including the aluminum foil. In order to reduce the amount of food and beverages to be discarded, a packaging material having a high gas barrier property and capable of storing the contents for as long as possible is preferable.

The present invention has been made in view of the above circumstances, and provides a laminate suitable for a packaging material having metallic luster, microwave oven suitability, and gas barrier properties, and a packaging material using the laminate. The purpose is to

The present invention includes a substrate, a gas barrier adhesive layer, a gloss layer, and a sealant layer, the gas barrier adhesive layer is disposed between the substrate and the sealant layer, and the substrate and the gas barrier adhesive A gloss layer is disposed in contact with the gas barrier adhesive layer between the layer and the layer, and the gloss layer contains a resin and metal particles, and the content of the metal particles in the gloss layer is 4.7 to 47.2% by mass. The present invention relates to a laminated body, and a packaging material obtained by using the laminated body.

According to the laminate of the present invention, it is possible to provide a packaging material having a metallic luster, suitability for a microwave oven and excellent gas barrier properties.

<Laminate>
The laminate of the present invention includes a substrate, a gloss layer, a gas barrier adhesive layer, and a sealant layer, and these layers are laminated in this order. A printing layer may be provided in addition to these layers.

(Base material)
The substrate can be used without particular limitation as long as it is a film or sheet having excellent chemical and physical strengths (the film is also a generic term for films and sheets unless otherwise specified below). The base material may be a monolayer film or a multilayer laminated film. The content can be appropriately selected according to the usage conditions such as the content and type of the packaging material described below and the presence or absence of heat treatment after filling the content.

Specific examples of the base material include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, polypropylene, polybutene, polyvinyl alcohol, ethylene-vinyl acetate copolymer, ionomer, ethylene- (Meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-propylene copolymer, methylpentene, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, Polycarbonate, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), poly Examples thereof include, but are not limited to, a resin film such as butylene terephthalate and polyethylene naphthalate, a K-coated stretched polypropylene film, a K-coated stretched nylon film, and a composite film obtained by laminating two or more of these films.

Among them, uniaxially or biaxially oriented polyester films such as polyethylene terephthalate and polyethylene naphthalate, uniaxially or biaxially oriented polyamide films such as nylon 6, nylon 66 and MXD6 (polymetaxylylene adipamide), biaxially oriented polypropylene films Etc. can be used suitably.

The film thickness of the substrate is not particularly limited, and may be appropriately selected within the range of 1 to 300 μm from the viewpoint of moldability and transparency. It is preferably in the range of 1 to 100 μm. If it is less than 1 μm, the strength is insufficient, and if it exceeds 300 μm, the rigidity becomes too high, which may make the processing difficult.

The film used as the base material was subjected to some surface treatment, for example, corona discharge treatment, ozone treatment, physical treatment such as low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, or the like, or a chemical agent. It may be one that has been subjected to a chemical treatment such as an oxidation treatment or other treatment.

The film to be used as the substrate is, for example, one kind or two or more kinds selected from the above-mentioned resins and is produced by a conventionally known film forming method such as an extrusion method, a cast molding method, a T die method, a cutting method, an inflation method or the like. can do. Alternatively, two or more kinds of resins selected from the above-mentioned resins may be used, and the resin can be manufactured by a multi-layer coextrusion film forming method. From the viewpoint of the strength, dimensional stability, and heat resistance of the film, it may be uniaxially or biaxially stretched using a tenter method, a tubular method, or the like.

The base film may contain an additive, if necessary. Specifically, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidation, slipperiness, releasability, flame retardancy, antifungal properties, electrical properties, strength, etc. are improved, For the purpose of modification, a plastic compounding agent or additive such as a lubricant, a cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent or a pigment can be added. The amount of the additive added is adjusted within a range that does not affect other performances.

(Glossy layer)
The gloss layer is a layer formed using a gloss layer-forming composition containing metal particles, a resin, and a solvent, and is disposed between the base material and a gas barrier adhesive layer described later. Examples of the embodiment of the composition for forming a glossy layer include inks such as gravure ink, flexo ink and screen ink, and coating agents.

Examples of the metal particles used in the composition for forming a glossy layer include particles of metals such as aluminum, gold, silver, copper, brass, titanium, chromium, nickel, nickel chrome, and stainless steel. Can be used together.

The shape of the metal particles is not particularly limited, but it is preferable that the shape of the metal particles is plate-like, because improvement of the gas barrier property of the gloss layer can be expected due to the maze effect. The average particle diameter of the metal particles is preferably 1 μm or more and 25 μm or less, and more preferably 1 μm or more and 10 μm or less. If it is less than 1 μm, a sufficient maze effect may not be expected. If it exceeds 25 μm, problems may occur when the gloss layer forming composition is applied by a gravure plate or a screen plate. For example, in the case of coating with a gravure plate, it becomes difficult for the metal particles to enter the cells of the gravure plate, and there is a risk that sufficient metal particles will not exist in the gloss layer and the metal gloss will be insufficient. When coating with a screen plate, it may cause clogging of the screen. When the plate-shaped metal particles are used, the thickness thereof is preferably 0.01 μm or more and 0.5 μm or less, and more preferably 0.03 μm or more and 0.08 μm or less.

The metal particles may be surface-treated. Examples of the surface treatment agent include organic fatty acids such as stearic acid, oleic acid, and palmitic acid, methylsilyl isocyanate, nitrocellulose, cellulose acetate propionate, cellulose acetate butyrate, and cellulose derivatives such as ethyl cellulose. These are adsorbed on the surface of the metal particles by a known and conventional method.

As the resin, cellulose resin, polyamide resin, cellulose/polyamide mixed resin, vinyl acetate resin, ethylene vinyl acetate resin, vinyl chloride/vinyl acetate copolymer resin, vinyl chloride/vinyl isobutyl ether copolymer resin, polyvinyl butyral resin, Modified polyolefin resin (chlorinated polypropylene etc.), non-modified polyolefin resin, acrylic resin, polystyrene, styrene-maleic acid resin, rosin modified maleic acid resin, polyester resin, urethane resin, urea resin, melamine resin, ketone resin, epoxy resin, Examples include petroleum resin, chlorinated rubber resin, cyclized rubber resin, shellac and the like. These can be used alone or in combination of two or more.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic or alicyclic hydrocarbons such as pentane, n-hexane, cyclohexane and heptane, esters such as ethyl acetate and propyl acetate, methanol, ethanol and n. Alcohols such as propanol, i-propanol, n-butanol and i-butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone, alkylene glycol monoalkyl such as ethylene glycol monoethyl ether and propylene glycol monomethyl ether Examples thereof include, but are not limited to, ether, petroleum naphtha, mineral spirits, water and the like. The solvent may be used alone or in combination of two or more.

The gloss layer forming composition may optionally contain a wax such as polyethylene wax, a filler such as silica, a plasticizer, a leveling agent, a surfactant, a dispersant, a defoaming agent, a chelating agent and the like. ..

When the amount of the metal particles blended in the gloss layer-forming composition is 4.7 to 47.2% by mass of the nonvolatile content of the gloss layer-forming composition, sparks when heated in a microwave oven can be suppressed. The blending amount of the resin and the additive is arbitrary, but as an example, it is 5% by mass or more. When the gloss layer forming composition is a gravure ink, it is preferably 25% by mass or less from the viewpoint of coating suitability and workability. When the gloss layer forming composition is a flexo ink, it is 30% by mass or less. It is preferably not more than mass %. The compounding amount of the solvent is adjusted so that the non-volatile content of the composition for forming a glossy layer is about 10 to 55%.

The thickness of the gloss layer is appropriately adjusted depending on the required metallic luster and the like, but is, for example, 0.3 μm or more and 5 μm or less. When the thickness of the gloss layer is too large, the gloss layer may be likely to cause blocking during storage in a roll after the gloss layer is provided on the sealant layer described later.

(Gas barrier adhesive layer)
The gas-barrier adhesive layer is a cured coating film of the gas-barrier adhesive, and is disposed between the gloss layer and the sealant and in contact with the gloss layer. The gas barrier adhesive that can be used is not particularly limited as long as it has gas barrier properties. In the present specification, a gas barrier adhesive is one that satisfies at least one of an oxygen barrier property of 140 cc/m ² /day/atm or a water vapor barrier property of 120 g/m ² /day or less. Say. Examples of commercially available products include "PASLIM" series such as PASLIM VM001 and PASLIM J350X manufactured by DIC Corporation, and "Maxive" manufactured by Mitsubishi Gas Chemical Company.

Examples of other adhesives having gas barrier properties include, for example, a polyol composition (A) containing at least one polyester polyol of the following (A1) to (A5) and a compound having at least two isocyanate groups in one molecule. A two-component adhesive composed of a polyisocyanate composition (B) containing (hereinafter also simply referred to as an isocyanate compound) is included.

(1) Polyester polyol (A1) obtained by reacting a polyester polyol having three or more hydroxyl groups with a carboxylic acid anhydride or a polycarboxylic acid
(2) Polyester polyol (A2) having a polymerizable carbon-carbon double bond
(3) Polyester polyol having glycerol skeleton (A3)
(4) Polyester polyol (A4) obtained by polycondensing an ortho-oriented polyvalent carboxylic acid and a polyhydric alcohol
(5) Polyester polyol having isocyanuric ring (A5)

The polyester polyol (A1) is obtained by reacting the polyester polyol (a1) having 3 or more hydroxyl groups with a carboxylic acid anhydride or a polyvalent carboxylic acid, and has at least one carboxyl group and 2 or more hydroxyl groups. Have. The polyester polyol (a1) can be obtained by making part of the polyvalent carboxylic acid or polyhydric alcohol trivalent or more.

The polycarboxylic acid used for preparing the polyester polyol (A1) preferably contains at least one of orthophthalic acid and orthophthalic anhydride. The polyester polyol obtained by using these compounds as the polyvalent carboxylic acid has excellent gas barrier properties and adhesiveness. The reason why the gas barrier property of the adhesive is excellent by using orthophthalic acid or orthophthalic anhydride is presumed to be that rotation of the polyester chain obtained by using orthophthalic acid or its acid anhydride is suppressed. It is presumed that the reason why the adhesiveness is excellent is that the polyester chain is asymmetric and thus exhibits non-crystallinity, and sufficient base material adhesion is imparted.

Examples of the trivalent or higher polycarboxylic acid include trimellitic acid and its acid anhydride, pyromellitic acid and its acid anhydride, and the like. In order to prevent gelation during synthesis, it is preferable to use a trivalent carboxylic acid as the trivalent or higher polycarboxylic acid.

Other polyvalent carboxylic acids may be copolymerized within a range that does not impair the effects of the present invention. Specifically, 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; 1 Alicyclic polycarboxylic acids such as 3,3-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 and acid anhydrides or ester-forming derivatives of these dicarboxylic acids , P-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and aromatic polycarboxylic acids such as ester-forming derivatives of these dihydroxycarboxylic acids, and the like, and one kind or a combination of two or more kinds is used. be able to. Among them, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid and its acid anhydride are preferable.

The polyhydric alcohol used for preparing the polyester polyol (A1) preferably contains at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. It is particularly preferable to use ethylene glycol because it is estimated that the smaller the number of carbon atoms between oxygen atoms is, the more the molecular chain does not become excessively flexible and oxygen is less likely to permeate.

Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl)isocyanurate, 1,2,4-butanetriol, pentaerythritol, and dipentaerythritol. To be In order to prevent gelation during synthesis, it is preferable to use a trihydric alcohol as the trihydric or higher polyhydric alcohol.

Other polyvalent carboxylic acids may be copolymerized within a range that does not impair the effects of the present invention. Specifically, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetra Aliphatic diols such as ethylene glycol, dipropylene glycol and tripropylene glycol; hydroquinone, resorcinol, catechol, naphthalene diol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, ethylene oxide extension products thereof, hydrogenated fat Examples thereof include aromatic polyhydric phenols such as ring compounds.

The polyester polyol (A1) is obtained by reacting a polyester polyol (a1) having three or more hydroxyl groups, which is a reaction product of the above-mentioned polyvalent carboxylic acid and polyhydric alcohol, with a polyvalent carboxylic acid or an acid anhydride thereof. It can be obtained. The proportion of hydroxyl groups reacted with the polycarboxylic acid is preferably 1/3 or less of the hydroxyl groups included in the polyester polyol (a1). The polyvalent carboxylic acid or its acid anhydride to be reacted with the polyester polyol (a1) is preferably divalent or trivalent. Succinic anhydride, maleic anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, 4-cyclohexene-1,2-dicarboxylic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, phthalic anhydride, 2, Examples thereof include 3-naphthalenedicarboxylic acid anhydride and trimellitic acid anhydride, but are not limited thereto.

The polyester polyol (A2) having a polymerizable carbon-carbon double bond can be obtained by using a component having a polymerizable carbon-carbon double bond as a polyvalent carboxylic acid or a polyhydric alcohol.

Maleic anhydride, maleic acid, fumaric acid, 4-cyclohexene-1,2-dicarboxylic acid and its acid anhydride, 3-methyl-4-cyclohexene-1 as a polyvalent carboxylic acid having a polymerizable carbon-carbon double bond , 2-dicarboxylic acid and its acid anhydride. Among them, maleic anhydride, maleic acid, and fumaric acid are preferable because it is estimated that the smaller the number of carbon atoms is, the more the molecular chain does not become excessively flexible and oxygen permeation is difficult.

Other polyvalent carboxylic acids may be copolymerized within a range that does not impair the effects of the present invention. Specifically, aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid; alicyclic compounds such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid Polycarboxylic acid; orthophthalic acid, terephthalic acid, isophthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyl Dicarboxylic acids, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acids and acid anhydrides or ester-forming derivatives of these dicarboxylic acids, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid And aromatic polyvalent carboxylic acids such as ester-forming derivatives of these dihydroxycarboxylic acids, and the like, and one kind or a combination of two or more kinds can be used. Moreover, these acid anhydrides can also be used. Among them, succinic acid, 1,3-cyclopentanedicarboxylic acid, orthophthalic acid, an acid anhydride of orthophthalic acid, and isophthalic acid are preferable in order to obtain gas barrier properties, and orthophthalic acid and its acid anhydride are more preferable.

Examples of the polyhydric alcohol having a polymerizable carbon-carbon double bond include 2-butene-1,4-diol.

Other polyhydric alcohols may be copolymerized as long as the effects of the present invention are not impaired. Specifically, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, cyclohexanedimethanol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol. , Dimethylbutanediol, butylethylpropanediol, aliphatic diols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol; hydroquinone, resorcinol, catechol, naphthalene diol, biphenol, bisphenol A, hisphenol F Examples thereof include tetramethylbiphenol, ethylene oxide extension products, and aromatic polyphenols such as hydrogenated alicyclic compounds. Among them, as the number of carbon atoms between oxygen atoms is smaller, it is presumed that the molecular chain does not become excessively flexible and oxygen is less likely to permeate, and therefore ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanediene. Methanol is preferred, and ethylene guclycol is more preferred.

Further, the polyester polyol (A2) having a polymerizable carbon-carbon double bond is a reaction product of the polyester polyol (a2) having a hydroxyl group and a carboxylic acid having a polymerizable double bond or a carboxylic acid anhydride. May be. As the carboxylic acid having a polymerizable double bond or an acid anhydride thereof, carboxylic acid having a polymerizable double bond such as maleic acid, maleic anhydride, or fumaric acid, unsaturated fatty acid such as oleic acid, sorbic acid, etc. Are listed. The polyester polyol (a2) preferably has 3 or more hydroxyl groups. When the polyester polyol (a2) has two or less hydroxyl groups, the polyester polyol (A2) has 0 to 1 hydroxyl groups, which makes it difficult for molecular extension to occur during the reaction with the polyisocyanate composition (B) described later. There is a risk that the adhesive strength will decrease.

The polyester polyol (A2) preferably has a double bond component ratio of 5 to 60 mass %. If the amount is less than 5% by mass, the number of crosslink points between the polymerizable double bonds will be small, and it will be difficult to obtain gas barrier properties. If it exceeds 60% by mass, the number of cross-linking points increases, and the flexibility of the cured coating film decreases, which may make it difficult to obtain adhesive strength. In this specification, the double bond component ratio in the polyester polyol (A2) is calculated using the following formula (a). In the following formula, the monomer means a polyvalent carboxylic acid or a polyhydric alcohol used for the synthesis of the polyester polyol (A2).

Further, as the polyester polyol (A2), a drying oil or a semi-drying oil can be mentioned. Examples of the drying oil or semi-drying oil include known and commonly used drying oils having a carbon-carbon double bond, semi-drying oils and the like.

The polyester polyol (A3) having a glycerol skeleton has a glycerol skeleton represented by the following general formula (1).

（一般式（１）中、Ｒ_１〜Ｒ_３は各々独立に、水素原子、または下記一般式（２）である。但し、Ｒ_１〜Ｒ_３のうち少なくとも一つは、下記一般式（２）で表される基を表す。）

(In the general formula (1), R _{1 to} R ₃ are each independently a hydrogen atom or the following general formula (2). However, at least one of R _{1 to} R ₃ is the following general formula (2). ) Represents a group represented by.)

（一般式（２）中、ｎは１〜５の整数を表し、Ｘは、置換基を有してもよい１，２−フェニレン基、１，２−ナフチレン基、２，３−ナフチレン基、２，３−アントラキノンジイル基、及び２，３−アントラセンジイル基から成る群から選ばれるアリーレン基を表し、Ｙは炭素原子数２〜６のアルキレン基を表す。）

(In the general formula (2), n represents an integer of 1 to 5, X represents a 1,2-phenylene group which may have a substituent, a 1,2-naphthylene group, a 2,3-naphthylene group, (It represents an arylene group selected from the group consisting of a 2,3-anthraquinonediyl group and a 2,3-anthracenediyl group, and Y represents an alkylene group having 2 to 6 carbon atoms.)

Polyester polyol (A3) is _a compound any one of R 1, _{R 2} and _{R 3} is a group represented by the general formula _(2), R 1, _{R 2} and one of _{R 3} 2 two generally formula Any two or more compounds of the compound represented by the formula (2) and the compound represented by the general formula (2) in which all of R ₁ , R ₂ and R ₃ are a mixture. May be. It is more preferable that all of R _{1 to} R ₃ are groups represented by the general formula (2).

In the general formula (2), when X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is any carbon atom on X, which is different from the free radical. Are bound to. As the substituent, 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, Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

Specific examples of Y in the general formula (2) include ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, An alkylene group having 2 to 6 carbon atoms such as a methylpentylene group and a dimethylbutylene group. A propylene group and an ethylene group are preferable, and an ethylene group is more preferable.

The polyester polyol (A3) is obtained by reacting glycerol, an aromatic polyvalent carboxylic acid having a carboxylic acid substituted at the ortho position or an acid anhydride thereof, and a polyhydric alcohol as essential components.

Examples of the aromatic polycarboxylic acid in which the carboxylic acid is substituted at the ortho position or its acid anhydride include orthophthalic acid or its acid anhydride, naphthalene 2,3-dicarboxylic acid or its acid anhydride, and naphthalene 1,2-dicarboxylic acid. Examples thereof include acids or acid anhydrides thereof, anthraquinone 2,3-dicarboxylic acids or acid anhydrides thereof, and 2,3-anthracenecarboxylic acids or acid anhydrides thereof. These compounds may have a substituent on any carbon atom of the aromatic ring. As the substituent, 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, Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

As the polycarboxylic acid, another polycarboxylic acid may be copolymerized as long as the effect of the present invention is not impaired. Specifically, 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; 1 Alicyclic polycarboxylic acids such as 3,3-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, diphenic acid and its acid anhydride, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid and these dicarboxylic acids Aromatic polyvalent carboxylic acids such as acid anhydrides or ester-forming derivatives, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids, and the like. One kind or two or more kinds can be used in combination. Among them, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalic acid and diphenic acid are preferable.

Examples of the polyhydric alcohol include alkylene diols 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 illustrated.

In addition, glycerol and a polyhydric alcohol other than an alkylenediol having 2 to 6 carbon atoms may be copolymerized within a range that does not impair the effects of the present invention. Specifically, aliphatic polyhydric alcohols such as erythritol, pentaerythritol, dipentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetraethylene glycol and tripropylene glycol, cyclohexanediene. Aliphatic polyhydric alcohols such as methanol and tricyclodecane dimethanol, hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, histophenol F, tetramethylbiphenol and other aromatic polyphenols, or ethylene oxide thereof. Examples include stretch products and hydrogenated alicyclic compounds.

When the polyol composition (A) contains the polyester polyol (A3) as a main component, the content of the glycerol residue in the polyester polyol (A3) in the solid content of the gas barrier adhesive is 5% by mass or more. preferable. The glycerol residue means a residue (C ₃ H ₅ O ₃ =89.07) excluding R _{1 to} R ₃ in the general formula (1), and is calculated using the following formula (b).

In addition, in said formula (b), P points out polyester polyol (A3). The resin solid content mass of the gas barrier adhesive is calculated from the total mass of the polyol composition (A) and the polyisocyanate composition (B) used, the dilution solvent (in the case of the adhesive for dry lamination), the polyisocyanate composition (B). The mass excluding the mass of volatile components and inorganic components contained in.

The polyester polyol (A4) obtained by polycondensing an ortho-oriented polyvalent carboxylic acid and a polyhydric alcohol is a polyvalent carboxylic acid containing at least one orthophthalic acid and its acid anhydride, ethylene glycol, and propylene. It comprises a polyhydric alcohol containing at least one selected from the group consisting of glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol. In particular, a polyester polyol in which the use ratio of the orthophthalic acid and its acid anhydride is 70 to 100% by mass based on the total amount of the polyvalent carboxylic acid is preferable.

As the polyvalent carboxylic acid, either orthophthalic acid or its acid anhydride is essential, but other polyvalent carboxylic acids may be copolymerized as long as the effects of the present invention are not impaired. Specifically, as the aliphatic polycarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and the like, as the unsaturated bond-containing polycarboxylic acid, maleic anhydride, maleic acid, Fumaric acid and the like, 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid as alicyclic polycarboxylic acids, and terephthalic acid, isophthalic acid and pyromellitic acid as aromatic polycarboxylic acids. 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 acids and acid anhydrides or ester-forming derivatives of these dicarboxylic acids; polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids Can be used alone or as a mixture of two or more. Of these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferable.

The polyhydric alcohol includes at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol, but other polyhydric alcohols may be used within the range not impairing the effects of the present invention. It may be copolymerized. Specifically, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetra Aliphatic diols such as ethylene glycol, dipropylene glycol, tripropylene glycol; hydroquinone, resorcinol, catechol, naphthalene diol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, ethylene oxide extension products, and hydrogenation of these Examples thereof include aromatic polyphenols such as alicyclic compounds.

The polyester polyol (A5) having an isocyanuric ring is represented by the following general formula (3).

（一般式（３）中、Ｒ_１〜Ｒ_３は各々独立して、−（ＣＨ_２）_ｎ１−ＯＨ（但し_ｎ１は２〜４の整数を表す）、又は下記一般式（４）で表される基を表す。但しＲ_１、Ｒ_２及びＲ_３の少なくとも１つは一般式（４）で表される基である。）

(In the general formula (3), R _{1 to} R ₃ are each independently represented by —(CH ₂ ) _{n 1} —OH (where _{n 1} represents an integer of 2 to 4) or the following general formula (4). (Wherein at least one of R ₁ , R ₂ and R ₃ is a group represented by the general formula (4).)

（一般式（４）中、ｎ２は２〜４の整数を表し、ｎ３は１〜５の整数を表し、Ｘは１，２−フェニレン基、１，２−ナフチレン基、２，３−ナフチレン基、２，３−アントラキノンジイル基、及び２，３−アントラセンジイル基から成る群から選ばれ、置換基を有していてもよいアリーレン基を表し、Ｙは炭素原子数２〜６のアルキレン基を表す。）

(In general formula (4), n2 represents an integer of 2 to 4, n3 represents an integer of 1 to 5, X represents a 1,2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group. , 2,3-anthraquinonediyl group and 2,3-anthracenediyl group, and represents an arylene group which may have a substituent, and Y represents an alkylene group having 2 to 6 carbon atoms. Represents.)

Polyester polyol (A5) _includes a compound any one of R 1, _{R 2} and _{R 3} is a group represented by the general formula _(4), R 1, _{R 2} and one of _{R 3} 2 two generally formula Any two or more compounds of the compound represented by the formula (4) and the compound represented by the general formula (4) in which all of R ₁ , R ₂ and R ₃ are a mixture. May be. It is more preferable that all of R _{1 to} R ₃ are groups represented by the general formula (4).

In the general formula (3), the alkylene group represented by —(CH2) _n1 — may be linear or branched. Among them, n1 is preferably 2 or 3, and most preferably 2.

In the general formula (4), when X is substituted with a substituent, it may be substituted with one or more substituents, and the substituent is any carbon atom on X different from the free radical. Are bound to. As the substituent, 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, Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

The substituent of X is preferably a hydroxyl group, a cyano group, a nitro group, an amino group, a phthalimido group, a carbamoyl group, an N-ethylcarbamoyl group or a phenyl group, and a hydroxyl group, a phenoxy group, a cyano group, a nitro group, a phthalimido group, A phenyl group is more preferred.

Specific examples of Y in the general formula (4) include ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, An alkylene group having 2 to 6 carbon atoms such as a methylpentylene group and a dimethylbutylene group. A propylene group and an ethylene group are preferable, and an ethylene group is more preferable.

The polyester polyol (A5) is obtained by reacting a triol having an isocyanuric ring, an aromatic polyvalent carboxylic acid having a carboxylic acid substituted at the ortho position or an acid anhydride thereof, and a polyhydric alcohol as essential components.

Examples of the triol having an isocyanuric ring include alkylene oxide adducts of isocyanuric acid such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid. Etc.

Examples of the aromatic polycarboxylic acid having an ortho-position substituted carboxylic acid or an acid anhydride thereof include orthophthalic acid or an acid anhydride thereof, naphthalene 2,3-dicarboxylic acid or an acid anhydride thereof, naphthalene 1,2-dicarboxylic acid. Examples thereof include acids or acid anhydrides thereof, anthraquinone 2,3-dicarboxylic acids or acid anhydrides thereof, and 2,3-anthracenecarboxylic acids or acid anhydrides thereof. These compounds may have a substituent on any carbon atom of the aromatic ring. As the substituent, 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, Examples thereof include a phthalimide group, a carboxyl group, a carbamoyl group, an N-ethylcarbamoyl group, a phenyl group and a naphthyl group.

As the polyhydric alcohol, an alkylene diol having 2 to 6 carbon atoms, specifically, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, Examples thereof include diols such as 1,6-hexanediol, methylpentanediol and dimethylbutanediol.

Among them, 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, and the carboxylic acid is in the ortho position. A polyester polyol (A5) having an isocyanuric ring, in which orthophthalic anhydride is used as the aromatic polyvalent carboxylic acid substituted with or or an acid anhydride thereof and ethylene glycol is used as the polyhydric alcohol, has excellent gas barrier properties and adhesiveness. Excellent and preferable.

The isocyanuric ring is highly polar and does not form hydrogen bonds. Generally, as a method of improving the adhesiveness, a method of blending a highly polar functional group such as a hydroxyl group, a urethane bond, an ureido bond, an amide bond is known, but a resin having these bonds forms an intermolecular hydrogen bond. It is easy and may impair the solubility in solvents such as ethyl acetate and 2-butanone that are often used in solvent-based adhesives, but the polyester resin having an isocyanuric ring does not impair the solubility, so it is easy. It can be diluted.

Moreover, since the isocyanuric ring is trifunctional, the polyester polyol compound having the isocyanuric ring as the center of the resin skeleton and having a polyester skeleton having a specific structure in its branched chain can obtain a high crosslink density. It is estimated that increasing the crosslink density can reduce the gaps through which a gas such as oxygen passes. As described above, the isocyanuric ring has a high polarity without forming intermolecular hydrogen bonds and a high crosslink density can be obtained, and therefore it is presumed that the gas barrier property and the adhesive property can be secured.

From such a viewpoint, when the polyol composition (A) contains the polyester polyol (A5) as a main component, the content of the isocyanuric ring in the polyester polyol (A5) in the solid content of the gas barrier adhesive is 5% by mass. The above is preferable. The isocyanuric ring means a residue (C ₃ N ₃ O ₃ =126.05) excluding R _{1 to} R ₃ in the general formula (3), and is calculated using the following formula (b).

In the above formula (c), P indicates polyester polyol (A5). The resin solid content mass of the gas barrier adhesive is calculated from the total mass of the polyol composition (A) and the polyisocyanate composition (B) used, the dilution solvent (in the case of the adhesive for dry lamination), the polyisocyanate composition (B). The mass excluding the mass of volatile components and inorganic components contained in.

The hydroxyl value of the polyester polyol is preferably 20 mgKOH/g or more and 250 mgKOH/g or less. When the hydroxyl value is less than 20 mgKOH/g, the viscosity of the polyol composition (A) becomes high because the molecular weight is too large, and good coating suitability cannot be obtained. When the hydroxyl value exceeds 250 mgKOH/g, the molecular weight is too small and the crosslink density of the cured coating film becomes too high, so that good adhesive strength cannot be obtained.

When the polyester polyol has an acid group, the acid value is preferably 200 mgKOH/g or less. When the acid value exceeds 200 mgKOH/g, the reaction between the polyol composition (A) and the polyisocyanate composition (B) becomes too fast, and good coating suitability cannot be obtained. Although the lower limit of the acid value of the polyester polyol is not particularly limited, it is, for example, 20 mgKOH/g or more. When the acid value is 20 mgKOH/g or more, good gas barrier properties and initial cohesive force can be obtained due to the interaction between molecules. The hydroxyl value of the polyester polyol can be measured by the hydroxyl value measuring method described in JIS-K0070, and the acid value can be measured by the acid value measuring method described in JIS-K0070.

It is particularly preferable that the number average molecular weight of the polyester polyol as described above is 300 to 5,000 because a crosslink density having an excellent balance between adhesiveness and gas barrier property can be obtained. More preferably, the number average molecular weight is 350 to 3000. When the molecular weight is less than 300, the cohesive force of the adhesive during coating becomes too small, which may cause problems such as deviation of the film during lamination and floating of the laminated film. On the other hand, if the molecular weight is higher than 5,000, the viscosity at the time of coating becomes too high and coating cannot be performed, or the adhesiveness may be low and lamination may not be possible. The number average molecular weight is calculated from the obtained hydroxyl value and the number of functional groups of the designed hydroxyl group.

The glass transition temperature of the polyester polyol is preferably −30° C. or higher and 80° C. or lower, more preferably 0° C. or higher and 60° C. or lower, and further preferably 25° C. or higher and 60° C. or lower. When the glass transition temperature exceeds 80° C., the flexibility of the polyester polyol near room temperature is low, so that the adhesiveness to the substrate is poor and the adhesiveness may be lowered. On the other hand, if the temperature is lower than -30°C, the molecular motion of the polyester polyol near room temperature is so strong that sufficient gas barrier properties may not be obtained.

The polyester polyol may be a polyester polyurethane polyol having a number average molecular weight of 1000 to 15000 obtained by urethane extension of the polyester polyols (A1) to (A5) by reaction with a diisocyanate compound. Since the urethane-extended polyester polyol has a molecular weight component of a certain level or more and a urethane bond, it has excellent gas barrier properties, excellent initial cohesive force, and is excellent as an adhesive for lamination.

The polyisocyanate composition (B), which is one component of the two-component adhesive having gas barrier properties, contains an isocyanate compound. As the isocyanate compound, conventionally known compounds can be used without particular limitation, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or Trimers of these isocyanate compounds, and excess amounts of these isocyanate compounds, such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane , Low molecular weight active hydrogen compounds such as glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine, and their alkylene oxide adducts, various polyester resins, polyether polyols, Examples thereof include adducts obtained by reacting polyamides with a polymer active hydrogen compound. You may use the polyester polyisocyanate obtained by making polyester polyols (A1)-(A5) and a diisocyanate compound react with the ratio of a hydroxyl group and an isocyanate group in isocyanate excess. These can be used alone or in combination of two or more.

A blocked isocyanate may be used as the isocyanate compound. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol, acetoxime, methylethylketoxime, cyclohexanone oxime, its oximes, methanol, Alcohols such as ethanol, propanol, butanol, ethylene chlorohydrin, 1,3-dichloro-2-
Halogen-substituted alcohols such as propanol, tertiary alcohols such as t-butanol and t-pentanol, and lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-propyrolactam. In addition, aromatic amines, imides, active methylene compounds such as acetylacetone, acetoacetic acid ester, and malonic acid ethyl ester, mercaptans, imines, ureas, diaryl compounds such as sodium bisulfite are also included. The blocked isocyanate is obtained by subjecting the above-mentioned isocyanate compound and an isocyanate blocking agent to an addition reaction by an appropriate method known in the art.

Among them, xylylene diisocyanate, hydrogenated xylylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate are preferred because good gas barrier properties are obtained, and metaxylylene diisocyanate, an isocyanate compound having a metaxylene skeleton such as metahydrogenated xylylene diisocyanate. Is more preferably used.

Examples of the isocyanate compound having a meta-xylene skeleton include a trimer of xylylene diisocyanate, a buret body synthesized by a reaction with an amine, and an adduct body reacted with an alcohol. When the adhesive is solvent type, it is preferable to use the adduct body because it has better solubility in the organic solvent used for the solvent type adhesive as compared with the trimer and the burette body. As the adduct, an adduct formed by reacting with an alcohol appropriately selected from the above-mentioned low-molecular active hydrogen compounds can be used, but among them, trimethylolpropane, glycerol, triethanolamine, and ethylene oxide addition of metaxylenediamine. An adduct body with an object is preferable.

When a composition containing a polyester polyol having carboxylic acid groups remaining, such as the polyester polyol (A1), is used as the polyol composition (A), the polyisocyanate composition (B) contains an epoxy compound. You can leave. Examples of the epoxy compound include diglycidyl ether of bisphenol A and its oligomer, hydrogenated bisphenol A diglycidyl ether and its oligomer, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and p-oxybenzoic acid diester. Glycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1 ,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl Examples include propylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and triglycidyl ether of glycerol alkylene oxide adduct.

When an epoxy compound is used, a generally known epoxy curing accelerator may be appropriately added for the purpose of accelerating curing as long as the object of the present invention is not impaired.

When a composition containing a polyol having a polymerizable carbon-carbon double bond such as a polyester polyol (A2) is used as the polyol composition (A), in order to accelerate the polymerization of the carbon-carbon double bond, A known polymerization catalyst can be used in combination, and a transition metal complex can be given as an example. The transition metal complex is not particularly limited as long as it is a compound having an ability to oxidatively polymerize a polymerizable double bond. For example, with metals such as cobalt, manganese, lead, calcium, cerium, zirconium, zinc, iron, copper, octylic acid, naphthenic acid, neodecanoic acid, stearic acid, resin acid, tall oil fatty acid, tung oil fatty acid, linseed oil fatty acid, A salt with soybean oil fatty acid or the like can be used. The blending amount of the transition metal complex is preferably 0 to 10 parts by mass, and more preferably 0 to 3 parts by mass with respect to the resin solid content contained in the polyol composition (A).

In the polyol composition (A) and the polyisocyanate composition (B), the equivalent ratio of the hydroxyl group contained in the polyol composition (A) and the isocyanate group contained in the polyisocyanate composition (B) is 1/0. It is preferable to mix it so as to be 5 to 1/10, and it is more preferable to mix it so as to be 1/1 to 1/5. When the isocyanate compound is excessive, the excess isocyanate compound remaining in the cured coating film of the adhesive may bleed out from the adhesive layer. On the other hand, if the reactive functional group contained in the polyisocyanate composition (B) is insufficient, the adhesive strength may be insufficient.

Various additives may be added to the gas barrier adhesive in a range that does not impair the adhesiveness and the gas barrier property.

An inorganic filler may be used as such an additive. Examples of the inorganic filler include silica, alumina, aluminum flakes, glass flakes and the like. Particularly, it is preferable to use a plate-like inorganic compound as the inorganic filler because the adhesive strength, the gas barrier property, the light shielding property and the like are improved. Examples of the plate-like inorganic compound include hydrous silicates (phylosilicate minerals, etc.), kaolinite-serpentine clay minerals (halloysite, kaolinite, enderite, dickite, nacrite, antigorite, chrysotile, etc.), pyrophyllite. Light-talc group (pyrophyllite, talc, chelorii, etc.), smectite group clay mineral (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, etc.), vermiculite group clay mineral (vermiculite, etc.), mica or Mica clay minerals (mica, phlogopite and other mica, margarite, tetrasilylic mica, teniolite, etc.), chlorite group (cookite, sudoite, clinochlore, chamosite, nimite, etc.), hydrotalcite, plate-like sulfuric acid Examples include barium, boehmite, and aluminum polyphosphate. These minerals may be natural clay minerals or synthetic clay minerals. The plate-like inorganic compound may be used alone or in combination of two or more.

The plate-like inorganic compound may be an ionic compound having a charge between layers or a nonionic compound having no charge. The presence or absence of charges between layers does not directly affect the gas barrier properties of the adhesive layer. However, ionic plate-like inorganic compounds and inorganic compounds that swell in water have poor dispersibility in solvent-based adhesives, and increasing the amount added increases the viscosity of the adhesive and makes it thixotropic. Therefore, the coating suitability may be reduced. For this reason, it is preferable that the plate-like inorganic compound is nonionic and does not have interlayer charge.

The average particle size of the plate-like inorganic compound is not particularly limited, but as an example, it is preferably 0.1 μm or more, and more preferably 1 μm or more. When it is smaller than 0.1 μm, the bypass route for oxygen molecules is not long, and improvement in gas barrier properties cannot be expected sufficiently. The upper limit of the average particle size is not particularly limited, but if the particle size is too large, defects such as streaks may occur on the coated surface depending on the coating method. Therefore, as an example, the average particle size is preferably 100 μm or less, and more preferably 20 μm or less. In the present specification, the average particle size of the plate-like inorganic compound refers to the particle size having the highest appearance frequency when the particle size distribution of the plate-like inorganic compound is measured by a light scattering measurement device.

The aspect ratio of the plate-like inorganic compound is preferably high in order to improve the gas barrier property due to the maze effect of oxygen. Specifically, it is preferably 3 or more, more preferably 10 or more, and most preferably 40 or more.

The compounding amount of the plate-like inorganic compound is arbitrary, but as an example, when the total solid mass of the polyol composition (A), the polyisocyanate composition (B), and the plate-like inorganic compound is 100 mass, the plate-like inorganic compound is The compounding amount of the inorganic compound is 5 to 50 parts by mass.

The gas barrier adhesive may include an adhesion promoter. Examples of the adhesion promoter include silane coupling agents such as hydrolyzable alkoxysilane compounds, titanate coupling agents, aluminum coupling agents, epoxy resins and the like. Silane coupling agents and titanate coupling agents can be expected to have the effect of improving the adhesiveness to various film materials.

When acid resistance is required for the gas barrier adhesive layer, the gas barrier adhesive may contain a known acid anhydride. Examples of the acid anhydride include phthalic acid anhydride, succinic acid anhydride, het acid anhydride, hymic acid anhydride, maleic acid anhydride, tetrahydrophthalic acid anhydride, hexahydraphthalic acid anhydride, tetrapromphthalic acid. Anhydride, tetrachlorophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenotetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 5-(2 , 5-oxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, styrene maleic anhydride copolymer and the like.

If necessary, a compound having an oxygen scavenging function may be added. Examples of compounds having an oxygen scavenging function include low molecular weight organic compounds that react with oxygen, such as hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, and pyrogallol, and cobalt, manganese, nickel, iron, Examples thereof include transition metal compounds such as copper.

If necessary, a tackifier such as a xylene resin, a terpene resin, a phenol resin, or a rosin resin may be added in order to improve the adhesiveness to various film materials immediately after coating. When these are added, the blending amount thereof is preferably in the range of 0.01 to 5 parts by mass based on 100 parts by mass of the total solid content of the polyol composition (A) and the polyisocyanate composition (B).

When the polyol composition (A) contains the polyester polyol (A2), active energy rays can be used as a method for reacting the polymerizable carbon-carbon double bond. As the active energy ray, a known technique can be used, and it can be cured by irradiation with electron beam, ultraviolet ray, ionizing radiation such as γ ray or the like. In the case of curing with ultraviolet light, a known ultraviolet irradiation device equipped with a high pressure mercury lamp, an excimer lamp, a metal halide lamp, etc. can be used.

In the case of curing by irradiation with ultraviolet rays, a photo (polymerization) initiator that generates radicals or the like by irradiation with ultraviolet rays is, if necessary, 0.1 to 20 parts by mass based on 100 parts by mass of the polyester polyol (A2). It is preferable to add to some extent.

Examples of radical-generating photo(polymerization) initiators include benzyl, benzophenone, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and other hydrogen abstraction type, benzoin ethyl ether, diethoxyacetophenone, benzylmethyl ketal, and hydroxy. Examples include photocleavable types such as cyclohexyl phenyl ketone and 2-hydroxy-2-methyl phenyl ketone. These may be used alone or in combination of two or more.

In addition, the gas barrier adhesive may contain a stabilizer (antioxidant, heat stabilizer, ultraviolet absorber, etc.), plasticizer, antistatic agent, lubricant, antiblocking agent, colorant, crystal nucleating agent, etc. .. These various additives may be added to either one or both of the polyol composition (A) and the polyisocyanate composition (B) in advance, or the polyol composition (A) and the polyisocyanate composition ( It may be added when mixing with B).

The gas barrier adhesive used in the present invention may be in a solvent type or a solventless type. In the present specification, the solvent-based adhesive refers to a method of applying an adhesive to a base material, heating it in an oven or the like to volatilize the organic solvent in the coating film, and then bonding it to another base material, so-called dry Refers to the form used in the laminating method. As the solvent used, toluene, xylene, methylene chloride, tetrahydrofuran, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylol, n-hexane, cyclohexane, etc. Are listed. Either one or both of the polyol composition (A) and the polyisocyanate composition (B) contains the above-mentioned organic solvent. In the case of a solvent type, the solvent used as a reaction medium during the production of the constituents of the polyol composition (A) or the polyisocyanate composition (B) may be used as a diluent during coating.

The solventless adhesive is used in a so-called non-solvent laminating method in which an adhesive is applied to a base material and then bonded to another base material without going through a step of heating in an oven or the like to volatilize the solvent. It refers to the form. Neither the polyol composition (A) nor the polyisocyanate composition (B) contains substantially the above-mentioned organic solvent. The polyol composition (A) or the polyisocyanate composition (B) cannot be completely removed without removing the constituents of the polyol composition (A) or the polyisocyanate composition (B) and the organic solvent used as a reaction medium during the production of the raw material. When a trace amount of the organic solvent remains in B), it is understood that the organic solvent is not substantially contained. Further, when the polyol composition (A) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the polyisocyanate composition (B) and becomes a part of the coating film, so that it is not necessary to volatilize it after coating. Therefore, such a form is also treated as a solventless adhesive.

(Sealant layer)
The sealant layer is a layer of heat-sealable resin that can be melted by heat and fused to each other. Suitable resins for the sealant layer include polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-( (Meth) acrylic acid copolymer, ethylene-(meth) ethyl acrylate copolymer, ethylene-propylene copolymer, methyl pentene polymer, olefin resin such as polyethylene or polypropylene acrylic acid, methacrylic acid, maleic anhydride, Modified olefin resin modified with fumaric acid or other unsaturated carboxylic acid, terpolymer of ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid, cyclic polyolefin, cyclic olefin copolymer, polyethylene terephthalate (PET), polyacrylonitrile (PAN) and the like. A resin film, sheet, or other coating film made of one or more of these resins can be used as the sealant layer.

As the film forming the sealant layer, any of unstretched, uniaxially stretched and biaxially stretched films can be used.

The stretched film stretched in the biaxial direction is, for example, longitudinally stretched 2 to 4 times by a roll stretching machine at 50 to 100° C., and further horizontally stretched 3 to 5 times by a tenter stretching machine in an atmosphere at 90 to 150° C. Then, it is obtained by subsequent heat treatment with a tenter stretching machine in an atmosphere of 100 to 240°C. Alternatively, simultaneous biaxial stretching and sequential biaxial stretching may be used.

An easily peelable sealant film (easy peel film) may be used for the sealant layer. As the easily peelable sealant film, any of an interfacial peeling type, a cohesive peeling type, and an interlayer peeling type can be applied, and can be appropriately selected according to the type and required characteristics of the packaging material described later. The index of easy peeling property is appropriately set according to the type of packaging material and the required characteristics, but the seal strength is 2 to 20 N/15 mm as an example. For example, a polymer blend of a phase separation system in which polypropylene is combined with high-density dense polyethylene, low-density polyethylene, ethylene-vinyl acetate copolymer, and the like can exhibit easy peeling property.

The film thickness of the sealant layer can be arbitrarily selected, but when applied to a packaging material described later, for example, it is selected in the range of 5 to 500 μm. The thickness is more preferably 10 to 250 μm, further preferably 15 to 100 μm. If it is less than 5 μm, sufficient laminating strength as a packaging material cannot be obtained, and further, puncture resistance and the like may be deteriorated. If it exceeds 250 μm, the cost is increased and the film becomes hard and the workability is deteriorated.

(Print layer)
The laminate of the present invention may have a printing layer, if necessary. The position of the printing layer is arbitrary, but as an example, it is provided on the surface of the base material opposite to the surface on which the gas barrier adhesive layer is provided, or between the base material and the gloss layer. The printing layer is formed by various printing inks such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink by a general printing method that has been conventionally used for printing on a polymer film.

(Laminate and other layers)
The layered product of the present invention may have other layers as needed. For example, a film may be arranged between the gas barrier adhesive layer and the sealant layer. As the film, the same films as those exemplified as the substrate can be used. Uniaxially or biaxially oriented polyester film such as polyethylene terephthalate or polyethylene naphthalate, uniaxially or biaxially oriented polyamide film such as nylon 6, nylon 66, MXD6 (polymethaxylylene adipamide) or biaxially oriented polypropylene film, etc. It can be preferably used.

When the film is arranged between the gas barrier adhesive layer and the sealant layer, the film and the sealant layer may be bonded together via an adhesive. The adhesive used at this time may or may not be the above-mentioned gas barrier adhesive. The film may be bonded to the base material (gloss layer) via the gas barrier adhesive layer, or another layer may be disposed between the film and the gas barrier adhesive layer. ..

(Method for manufacturing laminated body)
The laminate of the present invention is obtained by laminating a base material provided with a gloss layer and a sealant layer with a gas barrier adhesive by a dry laminating method or a non-solvent laminating method. The laminated body has metallic luster and suitability for a microwave oven, has excellent gas barrier properties, and can be used as a gas barrier laminated body.

If the gas-barrier adhesive is solvent-based, apply the gas-barrier adhesive to either one of the base material and the sealant layer using a roll such as a gravure roll, and evaporate the organic solvent by heating in an oven or the like. Then, the other is bonded to obtain the laminate of the present invention. It is preferable to perform aging treatment after laminating. The aging temperature is preferably room temperature to 80° C., and the aging time is preferably 12 to 240 hours.

When the gas-barrier adhesive is a solventless type, the gas-barrier adhesive preheated to about 40° C. to 100° C. is applied to either one of the base material and the sealant layer using a roll such as a gravure roll. Immediately thereafter, the other is bonded to obtain the laminate of the present invention. It is preferable to perform aging treatment after laminating. The aging temperature is preferably room temperature to 70° C., and the aging time is preferably 6 to 240 hours.

The coating amount of the gas barrier adhesive is adjusted appropriately. In the case of a solvent type, for example, the solid content is adjusted to 1 g/m ² or more and 10 g/m ² or less, preferably 1 g/m ² or more and 5 g/m ² or less. In the case of a solventless type, the amount of the adhesive applied is, for example, 1 g/m ² or more and 10 g/m ² or less, preferably 1 g/m ² or more and 5 g/m ² or less.

<Packaging material>
The laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting foods, medicines and the like. When it is used as a multi-layer packaging material, its layer structure may change depending on the contents, environment of use, and form of use.

The packaging material of the present invention is obtained by using the laminate of the present invention, stacking the sealant films of the laminate so as to face each other, and then heat-sealing the peripheral edges thereof. As the bag-making method, the laminate of the present invention is folded, or the surfaces of the inner layers of the laminate are opposed to each other (the surface of the sealant film), and the peripheral edges thereof are, for example, a side seal type, a two-side seal type, Three-sided seal type, four-sided seal type, envelope sticker seal type, joint seal sticker type (vertical pillow, horizontal pillow), pleated seal type, flat bottom seal type, square bottom seal type, gusset type, and other heat seal types The method of heat-sealing can be mentioned. The packaging material of the present invention can take various forms depending on the contents, the use environment, and the use form. Self-supporting packaging materials (standing pouches) are also possible. As a heat sealing method, a known method such as bar sealing, rotating roll sealing, belt sealing, impulse sealing, high frequency sealing, or ultrasonic sealing can be used.

After filling the contents of the packaging material of the present invention through the opening, the opening is heat-sealed to manufacture a product using the packaging material of the present invention. Contents to be filled include confectionery such as rice crackers, bean confectionery, nuts, biscuits and cookies, wafer confectionery, marshmallows, pies, half-cakes, candy, snack confectionery, bread, snack noodles, instant noodles, dried noodles, pasta. , Aseptic packed rice, elephant rice, rice porridge, packed rice cake, staples such as cereal foods, pickles, boiled beans, natto, miso, frozen tofu, tofu, nameko mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen Vegetables, agricultural products such as potato products, hams, bacon, sausages, chicken products, livestock products such as corned beef, fish ham and sausage, fish paste, fish paste, seaweed, dried bonito, salted fish, Smoked salmon, seafood products such as mentaiko, peaches, tangerines, pineapples, flesh such as apples, pears, cherries, corn, asparagus, mushrooms, onions, carrots, radish, potatoes and other vegetables, hamburgers, meat. Frozen side dishes such as balls, fries, gyoza and croquettes, prepared foods such as chilled side dishes, butter, margarine, cheese, cream, instant creamy powder, dairy products such as infant formula powder, liquid seasoning, retort Examples include foods such as curry and pet food. The packaging material of the present invention can also be used as a packaging material for cigarettes, disposable body warmers, pharmaceuticals such as infusion packs, cosmetics, and vacuum heat insulating materials.

Alternatively, the packaging material of the present invention may be a lid material using the laminate of the present invention.

Claims (5)

Including a substrate, a gas barrier adhesive layer, a gloss layer, and a sealant layer,
The gas barrier adhesive layer is arranged between the substrate and the sealant layer,
The gloss layer is disposed in contact with the gas barrier adhesive layer between the substrate and the gas barrier adhesive layer,
The said gloss layer contains resin and a metal particle, The content of the said metal particle in the said gloss layer is 4.7-47.2 mass %, The laminated body characterized by the above-mentioned. The laminate according to claim 1, wherein the metal particles are plate-shaped. The layered product according to claim 1 or 2 which has a printing layer arranged between said substrate and said gas barrier adhesives layer. The laminate according to claim 1 or 2, which has a printed layer arranged on a surface of the substrate opposite to the surface on which the gas barrier adhesive layer is arranged. A packaging material comprising the laminate according to any one of claims 1 to 4.