Laminates, packaging materials

Abstract

The present invention provides a packaging material that has excellent moldability, maintains its adhesive strength between layers even after heat fusion of sealant layers to seal the contents, and is free from appearance defects such as lifting between layers. [Solution] A laminate comprising a first substrate, a first adhesive layer, a second substrate, a second adhesive layer, a metal layer, and a sealant layer in this order, wherein the first and second adhesive layers are cured coating films of a two-component curable adhesive containing a polyisocyanate composition (X) and a polyol composition (Y), wherein the cured coating films of the polyisocyanate composition (X) and polyol composition (Y) have an initial stress of 0.5 MPa to 10 MPa at a tensile speed of 200 mm / min and 120°C, and a breaking elongation of 5% or more at a tensile speed of 200 mm / min and 23°C ± 5°C, and the laminate is formed by the adhesive, and a packaging material manufactured using the laminate.

Description

Technical Field

[0001] The present invention relates to a laminate and a packaging material.

Background Art

[0002] Packaging materials used for packaging various stored items such as foods, daily necessities, and electronic components need to protect the contents from impacts received during distribution and deterioration caused by oxygen and moisture. Therefore, functions such as strength, crack resistance, and gas barrier properties are required. When the contents are subjected to heat sterilization, retort resistance, heat resistance, etc. are necessary, and transparency may also be required so that the contents can be confirmed. However, it is difficult to satisfy all the necessary functions with a single type of material. For example, an unstretched polyolefin film used for sealing by heat sealing has excellent heat processing properties but insufficient oxygen barrier properties. On the contrary, a nylon film has excellent gas barrier properties but inferior water vapor barrier properties. For these reasons, laminates obtained by laminating different polymer materials or a polymer material and a metal substrate are widely used as packaging materials.

[0003] For these reasons, laminates obtained by laminating different polymer materials or a polymer material and a metal substrate are widely used as packaging materials. In addition, a laminate formed by molding the laminate to form one or more storage portions may be used as a packaging material (Patent Documents 1 - 3). A laminate in which one or more storage portions are formed seals the storage portions by being joined to a laminate in which storage portions of the same shape are formed or a laminate in which no storage portion is formed (not subjected to molding).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] The present invention aims to provide a laminate suitable for packaging materials that involve such molding, that is, a laminate for packaging materials that has excellent moldability, does not experience a decrease in inter-layer adhesive strength even after heat fusion of sealant layers to seal the contents, and does not have appearance defects such as lifting between layers. [Means for solving the problem]

[0006] The present invention relates to a laminate formed by an adhesive comprising a first substrate, a first adhesive layer, a second substrate, a second adhesive layer, a metal layer, and a sealant layer in this order, wherein the first and second adhesive layers are cured coating films of a two-component curable adhesive containing a polyisocyanate composition (X) and a polyol composition (Y), wherein the cured coating films of the polyisocyanate composition (X) and polyol composition (Y) have an initial stress of 0.5 MPa to 10 MPa at a tensile speed of 200 mm / min and 120°C, and a breaking elongation of 5% or more at a tensile speed of 200 mm / min and 23°C ± 5°C, and to a packaging material manufactured using said laminate. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a laminate for packaging materials that has excellent moldability, does not experience a decrease in inter-layer adhesive strength even after heat fusion of sealant layers to seal the contents, and does not have appearance defects such as lifting between layers. [Modes for carrying out the invention]

[0008] <Laminate> The laminate of the present invention comprises a first substrate, a first adhesive layer, a second substrate, a second adhesive layer, a metal layer, and a sealant layer in this order. The laminate of the present invention will be described in detail below.

[0009] (First substrate, second substrate) As the first and second base materials, resin films with excellent insulating properties and pinhole resistance are preferably used. Specifically, examples include resin films such as polyester resin, polyamide resin, epoxy resin, acrylic resin, fluororesin, polyurethane resin, silicon resin, phenolic resin, and mixtures or copolymers thereof. Among these, polyester resin and polyamide resin are preferred, and biaxially oriented polyester resin and biaxially oriented polyamide resin are more preferred. Specific examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymer polyester, and polycarbonate. Specific examples of polyamide resins include nylon 6, nylon 6,6, copolymers of nylon 6 and nylon 6,6, nylon 6,10, and polymetaxylylene adipamide (MXD6). It is preferable to use a polyester resin film as the first base material and a polyamide resin film as the second base material.

[0010] The film thickness of the first and second substrates can be adjusted as appropriate, but as an example, it is 10 to 50 μm, and more preferably 15 to 35 μm. When using a polyester resin film, the film thickness is preferably 9 μm to 50 μm, and when using a polyamide resin film, the film thickness is preferably 10 μm to 50 μm. Sufficient strength can be ensured as a packaging material, stress during stretch molding and deep drawing can be reduced, and moldability can be improved.

[0011] It is also preferable that the first and second substrates are subjected to surface treatments such as corona treatment, plasma treatment, ozone treatment, flame treatment, or radiation treatment.

[0012] (metal layer) The metal layer functions as a barrier layer to prevent water vapor, oxygen, light, etc., from entering the inside of the packaging material. Specifically, examples of metal layers include metal foils such as aluminum, stainless steel, titanium, and copper. It is preferable to use aluminum foil or stainless steel foil. It is preferable that at least one surface, preferably both surfaces, of the metal layer is chemically treated for purposes such as stabilizing the adhesion between layers and preventing dissolution and corrosion. Here, chemical treatment refers to a treatment that forms an acid-resistant film on the surface of the metal layer.

[0013] Examples of chemical treatments include, but are not limited to, undercoating treatment using coupling agents such as silane coupling agents and titanium coupling agents, and chromate treatment. An example of chromate treatment is a method in which a composition comprising phosphoric acid, at least one of chromic acid and chromium(III) salt, and at least one selected from the group consisting of metal salts of fluoride, nonmetal salts of fluoride, acrylic resin, chitosan derivative resin, and phenolic resin is applied to the surface of degreased aluminum foil and dried.

[0014] The thickness of the metal layer can be adjusted as appropriate, but as an example, it is 20 to 60 μm, preferably 20 to 50 μm, and more preferably 25 to 45 μm.

[0015] (First adhesive layer, second adhesive layer) The first adhesive layer is placed between the first substrate and the second substrate to bond them together. The second adhesive layer is placed between the second substrate and the metal layer to bond them together. Both the first and second adhesive layers are cured coatings of a two-component curing adhesive containing a polyisocyanate composition (X) and a polyol composition (Y). The polyisocyanate composition (X) and the polyol composition (Y) are mixed, and the coating is cured by aging at room temperature to 90°C for 1 day to 2 weeks until the reaction is complete. The resulting coating has a thickness of 100 μm, and the initial stress measured at 120°C and a tensile speed of 200 mm / min is between 0.5 MPa and 10 MPa. The elongation at break measured at 23°C ± 5°C and a tensile speed of 200 mm / min is 5% or more. This allows for the creation of laminates with excellent adhesive strength, moldability, heat resistance, and moisture heat resistance to various substrates.

[0016] Such an adhesive layer can be formed, for example, by a two-component curing adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y), wherein the cured coating film exhibits the above-mentioned physical properties. The first adhesive layer and the second adhesive layer may be formed by the same adhesive or by different adhesives.

[0017] The polyisocyanate composition (X) contains a polyurethane polyisocyanate (A1), which is a reaction product of a composition containing a polyisocyanate compound (a1) and a polyol compound (a2).

[0018] The polyisocyanate compound (a1) is not particularly limited and includes aromatic diisocyanates, aromatic aliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and biuret, nurate, adduct, allophanate, carbodiimide modified, and uretdione modified forms of these diisocyanates, which can be used individually or in combination.

[0019] Examples of aromatic diisocyanates include, but are not limited to, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate (also referred to as polymeric MDI or crude MDI), 1,3-phenylene diisocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4',4''-triphenylmethane triisocyanate, etc.

[0020] Aromatic aliphatic diisocyanate means an aliphatic isocyanate having one or more aromatic rings in the molecule, and examples include, but are not limited to, m- or p-xylylene diisocyanate (also known as XDI), α,α,α',α'-tetramethylxylylene diisocyanate (also known as TMXDI), etc.

[0021] Examples of aliphatic diisocyanates include, but are not limited to, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, etc.

[0022] Examples of the alicyclic diisocyanate include, but are not limited to, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, etc.

[0023] The polyisocyanate compound (a1) preferably contains at least one selected from aromatic diisocyanates and their derivatives, and preferably contains at least one selected from 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate (also referred to as polymeric MDI or crude MDI).

[0024] The proportion of at least one selected from aromatic diisocyanates and their derivatives in the polyisocyanate compound (a1) can be adjusted as appropriate. As an example, it is 10% by mass or more, more preferably 30% by mass or more. The entire amount of the polyisocyanate compound (a1) may be at least one selected from aromatic diisocyanates and their derivatives.

[0025] Examples of polyol compounds (a2) include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohesane, 2,2,4-trimethyl-1,3-pentanediol, and dimer diol; Aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

[0026] Polyether polyols obtained by ring-opening polymerization of aliphatic diols and / or aliphatic polyols with various cyclic ether-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;

[0027] Lactone-based polyester polyols obtained by polycondensation reactions of aliphatic diols and / or aliphatic polyols with various lactones such as lactanoides and ε-caprolactone; Polyester polyols obtained by polycondensation reactions of aliphatic diols and / or aliphatic polyols with polycarboxylic acids;

[0028] Bisphenols such as bisphenol A and bisphenol F; Examples include alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc., to bisphenols such as bisphenol A and bisphenol F. These can be used individually or in combination of two or more.

[0029] Polycarboxylic acids used in the synthesis of polyester polyols include aliphatic polycarboxylic acids such as malonic acid, ethyl malonic acid, dimethyl malonic acid, succinic acid, 2,2-dimethyl succinic acid, succinic anhydride, alkenyl succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid, and trimer acid;

[0030] Alkyl esters of aliphatic polycarboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimephosphate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0031] Alicyclic polycarboxylic acids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, hymic anhydride, and hetic anhydride;

[0032] Aromatic polycarboxylic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic acid dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride;

[0033] Methyl esters of aromatic polycarboxylic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylic acid; These are some examples, and one or more types can be used in combination.

[0034] The polyol compound (a2) is preferably one with a number-average molecular weight of 400 to 2000, and more preferably one with a number-average molecular weight of 500 to 2000. The number-average molecular weight used herein is the value measured by gel permeation chromatography (GPC) under the following conditions.

[0035] Measuring device: HLC-8320GPC, manufactured by Tosoh Corporation. Columns; manufactured by Tosoh Corporation: TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1000HXL Detector; RI (Differential Refractometer) Data processing; Tosoh Corporation Multi-Station GPC-8020 model II Measurement conditions: Column temperature 40°C Solvent: tetrahydrofuran Flow rate 0.35ml / min Standard; monodisperse polystyrene Sample: 100 μl of a tetrahydrofuran solution containing 0.2% by mass (based on resin solids content) filtered through a microfilter.

[0036] The polyol compound (a2) preferably contains a polyester polyol. Preferably, the polyester polyol in the polyol compound (a2) is 10% by mass or more, and more preferably 30% by mass or more. The entire amount of the polyol compound (a2) may be polyester polyol.

[0037] Polyurethane polyisocyanate (A1) is obtained by reacting a composition containing a polyisocyanate compound (a1) and a polyol compound (a2). The mixing ratio of the polyisocyanate compound (a1) and the polyol compound (a2) can be adjusted as appropriate. For example, a ratio is used such that the equivalent ratio of isocyanate groups to hydroxyl groups [NCO] / [OH] is in the range of 1.5 to 5.0.

[0038] The polyisocyanate composition (X) may contain a polyisocyanate compound (A2) other than polyurethane polyisocyanate (A1). As the isocyanate compound (A2), the same as those exemplified as polyisocyanate compound (a1) can be used.

[0039] The polyol composition (Y) contains a polyester polyol (B), which is a reaction product of a polyhydric alcohol and a polyhydric carboxylic acid. As the polyhydric alcohol, the same as those exemplified as polyol compound (a2) can be used.

[0040] Polycarboxylic acids used in the synthesis of polyester polyols (B) include aliphatic polycarboxylic acids such as malonic acid, ethyl malonic acid, dimethyl malonic acid, succinic acid, 2,2-dimethyl succinic acid, succinic anhydride, alkenyl succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid, and trimer acid;

[0041] Alkyl esters of aliphatic polycarboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimephosphate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0042] Alicyclic polycarboxylic acids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, hymic anhydride, and hetic anhydride;

[0043] Aromatic polycarboxylic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic acid dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride;

[0044] Methyl esters of aromatic polycarboxylic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylic acid; Examples include, and one or more types can be used in combination.

[0045] The number-average molecular weight of polyester polyol (B) can be adjusted as appropriate depending on the purpose, but as an example, it is between 400 and 100,000.

[0046] The hydroxyl value of polyester polyol (B) is preferably in the range of 1 to 300 mgKOH / g, more preferably 60 mgKOH / g or more, and 200 mgKOH / g or less.

[0047] The solid content acid value of polyester polyol (B) is not particularly limited, but is preferably 10.0 mgKOH / g or less. A value of 5.0 mgKOH / g or less is preferable due to superior resistance to humidity and heat. It may also be 0 mgKOH / g.

[0048] The adhesive used to form the first and second adhesive layers may contain components other than those described above. For example, the polyol composition (Y) may contain a polycarbonate polyol. The number average molecular weight (Mn) of the polycarbonate polyol is preferably in the range of 300 to 2000, as this results in an adhesive with high adhesion to various substrates and excellent resistance to humidity and heat. Its hydroxyl value is preferably in the range of 30 to 250 mgKOH / g, and more preferably in the range of 40 to 200 mgKOH / g. Furthermore, the polycarbonate polyol is preferably a polycarbonate diol.

[0049] When using polycarbonate polyols, it is preferable to use them in an amount of 50% by mass or less, and more preferably 30% by mass or less, relative to the total solid content of the polyol composition (Y).

[0050] Furthermore, the polyol composition (Y) may also contain a polyoxyalkylene-modified polyol. The number-average molecular weight (Mn) of the polyoxyalkylene-modified polyol is preferably in the range of 300 to 2000, as this results in an adhesive with high adhesion to various substrates and excellent resistance to humidity and heat. Its hydroxyl value is preferably in the range of 40 to 250 mgKOH / g, and more preferably in the range of 50 to 200 mgKOH / g. In addition, the polyoxyalkylene-modified polyol is preferably a polyoxyalkylene-modified diol.

[0051] When using a polyoxyalkylene-modified polyol, it is preferable to use it in an amount of 50% by mass or less, and more preferably 30% by mass or less, relative to the total solid content of the polyol composition (Y).

[0052] The polyol composition (Y) may contain resin components other than those described above (hereinafter also referred to as other resin components). When other resin components are used, it is preferable to use them in an amount of 50% by mass or less, and more preferably 30% by mass or less, relative to the total solid content of the polyol composition (Y). Specific examples of other resin components include epoxy resins. Examples of epoxy resins include bisphenol-type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; biphenyl-type epoxy resins such as biphenyl-type epoxy resin and tetramethylbiphenyl type epoxy resin; and dicyclopentadiene-phenol addition reaction type epoxy resins. These may be used individually or in combination of two or more types. Among these, bisphenol-type epoxy resin is preferred because it provides high adhesion to various substrates and excellent resistance to humidity and heat.

[0053] The number-average molecular weight (Mn) of the epoxy resin is preferably in the range of 300 to 2000, as this results in an adhesive with high adhesion to various substrates and excellent resistance to humidity and heat. Furthermore, the epoxy equivalent is preferably in the range of 150 to 1000 g / equivalent.

[0054] When using epoxy resin, it is preferable to use it in an amount of 50% by mass or less, and more preferably 30% by mass or less, relative to the total solid content of the polyol composition (Y).

[0055] The polyol composition (Y) may contain a tackifier. Examples of tackifiers include rosin-based or rosin ester-based tackifiers, terpene-based or terpene phenol-based tackifiers, saturated hydrocarbon resins, coumarone-based tackifiers, coumarone-indene-based tackifiers, styrene-based tackifiers, xylene-based tackifiers, phenol-based tackifiers, petroleum-based tackifiers, and ketone-based tackifiers. Ketone-based tackifiers and rosin-based or rosin ester-based tackifiers are preferred, and ketone-based tackifiers are more preferred. These may be used individually or in combination of two or more types. When a tackifier is used, it is preferable to use it at an amount of 50% by mass or less, and more preferably 30% by mass or less, relative to the total solid content of the polyol composition (Y).

[0056] Examples of rosin-based or rosin ester-based products include polymerized rosin, disproportionated rosin, hydrogenated rosin, maleated rosin, fumarated rosin, and their glycerin esters, pentaerythritol esters, methyl esters, ethyl esters, butyl esters, ethylene glycol esters, diethylene glycol esters, and triethylene glycol esters.

[0057] Examples of terpene or terpenephenol compounds include low-polymerization terpenes, α-pinene polymers, β-pinene polymers, terpenephenol compounds, aromatically modified terpenes, and hydrogenated terpenes.

[0058] Examples of petroleum resins include petroleum resins obtained by polymerizing petroleum fractions with 5 carbon atoms from pentene, pentadiene, isoprene, etc., petroleum resins obtained by polymerizing petroleum fractions with 9 carbon atoms from indene, methylindene, vinyltoluene, styrene, α-methylstyrene, β-methylstyrene, etc., C5-C9 copolymer petroleum resins obtained from the above various monomers and petroleum resins obtained by hydrogenating these, petroleum resins obtained from cyclopentadiene, dicyclopentadiene; and hydrides of these petroleum resins; and modified petroleum resins obtained by modifying these petroleum resins with maleic anhydride, maleic acid, fumaric acid, (meth)acrylic acid, phenol, etc.

[0059] As phenolic resin systems, condensates of phenols and formaldehyde can be used. Examples of phenols include phenol, m-cresol, 3,5-xylenol, p-alkylphenol, and resorcinol. Examples include resols obtained by addition reactions of these phenols with formaldehyde using an alkaline catalyst, and novolacs obtained by condensation reactions using an acid catalyst. Rosinphenol resins obtained by adding phenol to rosin using an acid catalyst and then thermal polymerization can also be given as examples.

[0060] While well-known and commonly used ketone resins can be cited, formaldehyde resins, cyclohexanone-formaldehyde resins, and ketonealdehyde condensation resins can be suitably used.

[0061] While tackifiers with various softening points can be obtained, from the viewpoint of compatibility when mixed with other resins constituting the polyol composition (Y), color tone, and thermal stability, ketone resin-based tackifiers with a softening point of 70 to 160°C, preferably 80 to 100°C, or rosin-based resins and their hydrogenated derivatives with a softening point of 80 to 160°C, preferably 90 to 110°C, are preferred, and ketone resin-based tackifiers with a softening point of 70 to 160°C, preferably 80 to 100°C, are more preferred. Furthermore, ketone resin-based tackifiers and hydrogenated rosin-based tackifiers with an acid value of 2 to 20 mg KOH / g and a hydroxyl value of 10 mg KOH / g or less are preferred, and ketone resin-based tackifiers with an acid value of 2 to 20 mg KOH / g and a hydroxyl value of 10 mg KOH / g or less are more preferred.

[0062] The adhesives used to form the first and second adhesive layers can be known phosphoric acids or their derivatives. This further improves the initial adhesion of the adhesive and eliminates problems such as tunneling.

[0063] Phosphates or their derivatives used here include, for example, phosphates such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and subphosphoric acid; condensed phosphates such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid; for example, monomethyl orthophosphoric acid, monoethyl orthophosphoric acid, monopropyl orthophosphoric acid, monobutyl orthophosphoric acid, mono-2-ethylhexyl orthophosphoric acid, monophenyl orthophosphoric acid, monomethyl phosphate, monoethyl phosphate, monopropyl phosphate, monobutyl phosphate, mono-2-ethylhexyl phosphate, and monophosphoric acid. Examples include mono- and diesterified compounds of nophenyl, di-2-ethylhexyl orthophosphate, dimethyl diphenyl orthophosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, and diphenyl phosphate; mono- and diesterified compounds of condensed phosphoric acid and alcohols; for example, those obtained by adding epoxy compounds such as ethylene oxide and propylene oxide to the aforementioned phosphoric acids; and epoxy phosphate esters obtained by adding the aforementioned phosphoric acids to aliphatic or aromatic diglycidyl ethers.

[0064] The above-mentioned phosphoric acids or their derivatives may be used individually or in combination of two or more types. The method of inclusion is simply to mix them in.

[0065] Furthermore, adhesives used to form the first and second adhesive layers may also contain adhesion promoters. Examples of adhesion promoters include silane coupling agents, titanate-based coupling agents, aluminum-based coupling agents, epoxy resins, and the like.

[0066] Examples of silane coupling agents include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; and hexamethyldisilazane and γ-mercaptopropyltrimethoxysilane.

[0067] Examples of titanate-based coupling agents include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxititanium.

[0068] Examples of aluminum-based coupling agents include acetalkoxyaluminum diisopropylate.

[0069] It is preferable to use a silane coupling agent as the adhesion promoter. Furthermore, the content (solids) of the adhesion promoter is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.7 parts by mass or more, per 100 parts by mass of the solids of the polyol composition (Y). Furthermore, the content (solids) of the adhesion promoter is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the solids of the polyol composition (Y).

[0070] The mixing ratio of the polysocianate composition (X) and the polyol composition (Y) is preferably in the range of 1.0 to 20.0, and more preferably in the range of 2.0 to 10.0, of the ratio of the number of moles of isocyanate groups [NCO] contained in the polysocianate composition (X) to the total number of moles of hydroxyl groups [OH] contained in the polyol composition (Y), namely, [NCO] / [OH]. This results in a two-component curing adhesive with superior moldability, heat resistance, and moisture heat resistance.

[0071] The adhesive used to form the first and second adhesive layers is prepared by mixing the polyisocyanate composition (X) and polyol composition (Y) described above, and aging the mixture at room temperature to 90°C for 1 day to 2 weeks until the reaction between the polyisocyanate composition (X) and polyol composition (Y) is complete. The resulting coating film, with a thickness of 100 μm, has an initial stress of 0.5 MPa to 10 MPa measured at 120°C and a tensile speed of 200 mm / min, and a breaking elongation of 5% or more measured at 23°C ± 5°C and a tensile speed of 200 mm / min. To determine whether the reaction between the polyisocyanate composition (X) and polyol composition (Y) is complete, the infrared absorption spectrum is measured. The absorption peak at a wavelength where the absorption does not increase or decrease due to the reaction between the polyisocyanate composition (X) and polyol composition (Y) is used as a reference. The reaction is determined to be complete when there is no change in the intensity of the absorption peak of the isocyanate group (or any change is within the range of measurement error).

[0072] Generally, adhesives that exhibit excellent bonding strength even in high-temperature environments tend to have hard coatings and poor moldability at room temperature. However, the adhesive of the present invention excels in both heat resistance and moldability. Therefore, it can be suitably used not only in applications where either heat resistance or moldability is required, but also in applications where both are required.

[0073] The initial stress of the adhesive of the present invention under the above conditions is preferably 0.5 MPa to 8 MPa, and more preferably 0.5 MPa to 5 MPa. In this specification, initial stress refers to the stress at the proportional limit of the stress-strain curve (the maximum point in the straight portion from the start of tension).

[0074] Furthermore, there is no particular upper limit to the elongation at break of the adhesive of the present invention under the above conditions, but as an example, it is 400% or less, and more preferably 300% or less.

[0075] The adhesive used to form the first and second adhesive layers may be either solvent-based or solvent-free. In this invention, "solvent-based" adhesive refers to an adhesive used in a method where the adhesive is applied to a substrate, heated in an oven or the like to evaporate the organic solvent in the coating, and then bonded to another substrate—a method known as dry lamination. Either the polysocianate composition (X) or the polyol composition (Y), or both, contain a highly soluble organic solvent capable of dissolving the polysocianate composition (X) or polyol composition (Y) used in this invention. In the case of the solvent-based type, the organic solvent used as a reaction medium during the production of the components of the polysocianate composition (X) or polyol composition (Y) may also be used as a diluent during painting. Examples of highly soluble organic solvents include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; dimethyl sulfoxide and dimethyl sulfamide.

[0076] In this specification, "solvent-free" adhesives refer to adhesives used in the so-called non-solvent laminating method, in which the polysocianate composition (X) and polyol composition (Y) substantially do not contain highly soluble organic solvents as described above, particularly ethyl acetate or methyl ethyl ketone, and the adhesive is applied to a substrate and then bonded to another substrate without the step of heating in an oven or the like to volatilize the solvent. If trace amounts of organic solvent remain in the polysocianate composition (X) or polyol composition (Y) due to incomplete removal of the components of the polysocianate composition (X) or polyol composition (Y) or organic solvents used as reaction media during the manufacture of their raw materials, it is understood that the adhesive is substantially solvent-free. Furthermore, if the polyol composition (Y) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the polysocianate composition (X) to become part of the coating film, so there is no need to volatilize it after application. Therefore, such forms are also treated as solvent-free adhesives.

[0077] The adhesives used to form the first and second adhesive layers, when solvent-free, preferably have a viscosity of 100 mPa·s to 4000 mPa·s at 80°C for the polyisocyanate composition (X), and more preferably 100 mPa·s to 3000 mPa·s. Similarly, preferably have a viscosity of 100 mPa·s to 4000 mPa·s at 80°C for the polyol composition (Y), and more preferably 100 mPa·s to 3000 mPa·s. This allows for an adhesive with an excellent balance of adhesive strength, moldability, and heat resistance. The viscosities of the polyisocyanate composition (X) and polyol composition (Y) in this specification were measured using a rotational viscometer with a cone-plate of 1° × 50 mm in diameter, a shear rate of 100 sec⁻¹, and at 80°C ± 1°C. The viscosity of the isocyanate composition (X) and the polyol composition (Y) can be adjusted by the polyisocyanate compound (A) or polyester polyol (B) used and the amount thereof. If the adhesive used to form the first and second adhesive layers is solvent-based, its viscosity can be adjusted by diluting it with an organic solvent.

[0078] The adhesive used to form the first and second adhesive layers may contain various additives such as UV absorbers, antioxidants, silicone-based additives, fluorine-based additives, rheology control agents, defoaming agents, antistatic agents, and antifogging agents.

[0079] The first and second adhesive layers are formed by conventionally known lamination methods, such as dry lamination or non-solvent lamination. As an example, an adhesive is applied to either the first or second substrate so that the adhesive layer thickness is, for example, 0.5 to 10 μm, and the other substrate is bonded to it. Subsequently, an adhesive is applied to the second substrate so that the adhesive layer thickness is, for example, 0.5 to 10 μm, and it is bonded to the metal layer. An aging treatment is performed at room temperature to 80°C for 72 to 240 hours to form the first and second adhesive layers. The aging treatment may be performed when forming the first adhesive layer, when forming the second adhesive layer, or simultaneously.

[0080] (Sealant layer) The sealant layer is located in the innermost layer when the laminate of the present invention is used as a packaging material, and when heat is applied, the sealant layers fuse together to seal the contents.

[0081] The resin components used in the sealant layer are not particularly limited as long as they are heat-sealable, but examples include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins.

[0082] Examples of polyolefins include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymer of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymer of propylene and ethylene); and ethylene-butene-propylene terpolymers. Among these polyolefins, polyethylene and polypropylene are preferred.

[0083] Cyclic polyolefins are copolymers of olefins and cyclic monomers. Examples of olefin monomers that make up cyclic polyolefins include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers that make up cyclic polyolefins include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkenes are preferred, and norbornene is more preferred.

[0084] Carboxylic acid-modified polyolefins are polymers obtained by modifying polyolefins through block polymerization or graft polymerization with carboxylic acids. Examples of carboxylic acids used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0085] Carboxylic acid-modified cyclic polyolefins are polymers obtained by copolymerizing a portion of the monomers constituting a cyclic polyolefin with α,β-unsaturated carboxylic acids or their anhydrides, or by block polymerization or graft polymerization of α,β-unsaturated carboxylic acids or their anhydrides to a cyclic polyolefin. The cyclic polyolefins to be modified with carboxylic acids are the same as described above. Furthermore, the carboxylic acids used for modification are the same as those used for modifying acid-modified cycloolefin copolymers.

[0086] The sealant layer may be formed by a single resin component, or by a blended polymer combining two or more resin components. Furthermore, the sealant layer may be formed as a single layer, or it may be formed as two or more layers made of the same or different resin components.

[0087] The thickness of the sealant layer can be adjusted as appropriate, but as an example, it is 10 to 100 μm, and preferably 20 to 90 μm.

[0088] The sealant layer may be provided by bonding a film made of the aforementioned resin to the metal layer using an adhesive, or it may be formed by extruding and laminating molten resin onto the metal layer directly or via a primer layer as needed.

[0089] Adhesives used for bonding a film made of sealant resin to a metal layer can be conventionally known adhesives that are well-known for such applications. Examples include a two-component curing adhesive containing an olefin resin having at least one selected from acidic groups and hydroxyl groups, and a curing agent having multiple functional groups that can react with acidic groups or hydroxyl groups, such as isocyanate groups or glycidyl groups, or a two-component curing adhesive combining a polyol and a polyfunctional isocyanate. In this case, the amount of adhesive applied can be adjusted as appropriate, but as an example, it is adjusted so that the film thickness after curing is 0.1 to 50 μm, preferably 1 to 30 μm.

[0090] If the adhesive used to bond a film made of sealant resin to a metal layer requires aging, the aging temperature can be adjusted as appropriate, but one example is room temperature to 90°C. The aging time can also be adjusted as appropriate, but one example is 1 day to 2 weeks.

[0091] (Other layers) The laminate of the present invention may include layers other than those described above. Examples of such layers include a coating layer, which will be described later, and a printed layer on which a lot number or the like is printed. The printed layer may be provided, for example, by inkjet printing.

[0092] (Coating layer) The laminate of the present invention may optionally include a coating layer on the first substrate (on the side opposite the metal layer of the first substrate) for the purpose of improving design, electrolyte resistance, abrasion resistance, and moldability. The coating layer is the outermost layer when the laminate of the present invention is used as packaging material, as viewed from the contents.

[0093] The coating layer can be formed from, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, etc., and is preferably formed from a two-component curing resin. Examples of two-component curing resins for forming the coating layer include two-component curing urethane resin, two-component curing polyester resin, and two-component curing epoxy resin. A matting agent may also be incorporated into the coating layer.

[0094] Examples of matting agents include particles with a particle size of approximately 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, but examples include metals, metal oxides, inorganic substances, and organic substances. Similarly, the shape of the matting agent is not particularly limited, but examples include spherical, fibrous, plate-like, amorphous, and balloon-like shapes. Specific examples of matting agents include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium dioxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, carbon black, carbon nanotubes, high-melting-point nylon, cross-linked acrylic, cross-linked styrene, cross-linked polyethylene, benzoguanamine, gold, aluminum, copper, and nickel. These matting agents may be used individually or in combination of two or more. Among these matting agents, silica, barium sulfate, and titanium dioxide are preferred from the viewpoint of dispersion stability and cost. In addition, the matting agent may be subjected to various surface treatments such as insulating treatment and high dispersibility treatment.

[0095] There are no particular limitations on the method for forming the coating layer, but one example is to apply a two-component curable resin that forms the coating layer onto one surface of the first substrate. If a matting agent is to be incorporated, the matting agent can be added to the two-component curable resin, mixed, and then applied.

[0096] <Packaging material> The packaging material of the present invention consists of a laminate of the present invention. One embodiment of the packaging material of the present invention is obtained by overlapping the surfaces of the sealant film of the present invention facing each other, and then heat-sealing the peripheral edges. As for the bag-making method, the laminate of the present invention can be folded or overlapped so that the inner layer surfaces (sealant film surfaces) face each other, and the peripheral edges can be heat-sealed in the form of, for example, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a gusset seal type, a pleated seal type, a flat-bottom seal type, a square-bottom seal type, a gusset type, or other heat-seal types. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage form. Self-standing packaging materials (standing pouches) are also possible. As for the heat-sealing method, known methods such as bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals can be used.

[0097] Other embodiments of the packaging material of the present invention include forming a laminate of the present invention to provide one or more recesses (pockets), and then laminating a conventionally known lid material (for example, aluminum foil coated with a heat-sealing agent) onto it; or preparing two laminates of the present invention each provided with one or more recesses, aligning these recesses, and heat-sealing the heat-seal layers together. The shape of the recesses is not particularly limited and may be rectangular, circular, elliptical, or any other shape.

[0098] Conventional methods such as pressure molding, vacuum molding, and plug molding can be used as molding methods. During molding, the laminate may be heated and softened using a heater or the like, or it may be molded at room temperature.

[0099] Such packaging materials are suitably used, for example, as packaging materials for pet food, pharmaceuticals, cosmetics such as lotions and emulsions, and batteries.

[0100] <Battery packaging material> Among the packaging materials of the present invention, the battery packaging material is used as a battery container that seals and houses battery elements such as a positive electrode, a negative electrode, and an electrolyte.

[0101] Specifically, a battery is provided using the battery packaging material of the present invention, which covers a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte, with the metal terminals connected to the positive and negative electrodes respectively protruding outward, such that a flange portion (an area where sealant layers come into contact) is formed around the periphery of the battery element, and then heat-seals the sealant layers of the flange portion to seal it. When housing a battery element using the battery packaging material of the present invention, the sealant portion of the battery packaging material of the present invention is used so that it faces inward (the surface in contact with the battery element).

[0102] The battery packaging material of the present invention may be used for either primary or secondary batteries, but is preferably used for secondary batteries. The type of secondary battery to which the battery packaging material of the present invention is applied is not particularly limited, and examples include lithium-ion batteries, lithium-ion polymer batteries, lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, capacitors, and the like. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries are particularly suitable applications for the battery packaging material of the present invention. [Examples]

[0103] The present invention will be described in more detail below with reference to specific synthesis examples and embodiments, but the present invention is not limited to these embodiments. In the following examples, "parts" and "%" represent "parts by mass" and "mass%", respectively, unless otherwise specified.

[0104] <Preparation of polyisocyanate composition (X)> (Synthesis of polyisocyanate composition (X-1)) In a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 10.0 parts by mass of isocyanurate of 1,6-hexamethylene diisocyanate (Desmodule N3300, manufactured by Covestro) and 38.00 parts by mass of 4,4'-diphenylmethane diisocyanate (Millionate MT-F, manufactured by Tosoh Corporation) were charged and heated to 60°C while stirring under a nitrogen gas stream. 42.00 parts by mass of polyester polyol obtained from sebacic acid and 3-methyl-1,5-pentanediol (Kuraray Polyol P-1050, Mn=990, manufactured by Kuraray Co., Ltd.) were added dropwise to the vessel over 2 hours using a dropping funnel. The mixture was then heated further and maintained at an internal temperature of 80°C for 4 hours until the NCO group content reached 12.7%, after which it was cooled to 50°C. Next, 10.00 parts by mass of carbodiimide-modified diphenylmethane diisocyanate (manufactured by BIP, Luplanate MM103-B) was added to the container and stirred for 1 hour until homogenized, to obtain a polyisocyanate composition (X-1) containing polyurethane polyisocyanate (A1-1) with an NCO group content of 14.4%.

[0105] (Synthesis of polyisocyanate composition (X-2)) In a polyester reaction vessel equipped with a stirrer, nitrogen gas inlet tube, Snider tube, and condenser, 79.27 parts of ethylene glycol, 59.25 parts of phthalic anhydride, 87.68 parts of adipic acid, and 0.02 parts of titanium tetraisopropoxide were charged. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 220°C. The esterification reaction was terminated when the acid value fell to 1 mg KOH / g or less, yielding a polyester intermediate with a number average molecular weight of 850.

[0106] In a reaction vessel equipped with a stirrer, nitrogen gas inlet tube, Snider tube, cooling condenser, and dropping funnel, 69.06 parts of xylylene diisocyanate and 30.61 parts of myrionate MN (a mixture of 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate) were added and heated to 70°C while stirring. 100.33 parts of polyester intermediate were added dropwise over 2 hours using a dropping funnel, and the mixture was stirred for a further 4 hours to obtain polyurethane polyisocyanate (A1-2) with an NCO group content of 15.4%. This was used as polyisocyanate composition (X-2).

[0107] <Preparation of polyol composition (Y)> (Synthesis Example 10) Synthesis of Polyol Composition (Y-3) In a polyester reaction vessel equipped with a stirrer, nitrogen gas inlet tube, Snider tube, and condenser, 20.98 parts of ethylene glycol, 0.12 parts of glycerin, 50.94 parts of 1,3,5-tris(2-hydroxyethyl)isocyanuric acid, and 50.41 parts of phthalic anhydride were charged. The mixture was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 220°C. The esterification reaction was terminated when the acid value fell to 1 mg KOH / g or less, yielding a polyester polyol (B1-1) with a number average molecular weight of 670. The hydroxyl value was 230.2 mg KOH / g. This was diluted with ethyl acetate and used as polyol composition (Y-3).

[0108] In addition, HA-930B (manufactured by DIC Corporation, polyester polyol) was used as polyol composition (Y-1), and HA-700B (manufactured by DIC Corporation, polyester polyol) was used as polyol composition (Y-2).

[0109] <Preparation of adhesive composition> (Example 1) Polyisocyanate composition (X-1) and polyol composition (Y-1) were measured out so that the ratio of moles of isocyanate groups [NCO] in polyisocyanate composition (X-1) to moles of hydroxyl groups [OH] in polyol composition (Y-1) was 4.2, and the mixtures were thoroughly stirred until completely mixed to prepare the adhesive of Example 1.

[0110] (Example 2), (Example 3) Adhesives for Examples 2 and 3 were manufactured in the same manner as in Example 1, except that the materials and formulations used for preparing the adhesive were adjusted to the values ​​listed in Table 2. (Comparative Example 1), (Comparative Example 2) The adhesives of Comparative Examples 1 and 2 were manufactured in the same manner as in Example 1, except that the materials and formulations used for preparing the adhesive were adjusted to the values ​​shown in Table 2.

[0111] Polyisocyanate compositions (X-1) and (X-2), and polyol compositions (Y-1) and (Y-2) were used without dilution with organic solvents. Their viscosities at 80°C are shown in Table 1. Polyol composition (Y-3) was used after dilution with ethyl acetate, and the values ​​listed in Table 2 include the solvent.

[0112] [Table 1]

[0113] <Measurement of mechanical properties> (Initial stress) The adhesives from Examples 1-3 and Comparative Examples 1 and 2 were coated into 100 μm thick films, cut into dumbbell shapes measuring 25 mm in width and 115 mm in length, and used as test specimens. In accordance with JIS K7127 (1999), the stress at the proportional limit (initial stress) was measured and summarized in the table using a Tensilon tester manufactured by Orientec Co., Ltd., under the conditions of a chuck distance of 20 mm, a tensile speed of 200 mm / min, and a temperature of 120°C. The unit is MPa.

[0114] (Growth rate) Test specimens for Examples 1-3 and Comparative Examples 1 and 2 were prepared in the same manner as for initial stress measurement. The tensile elongation at fracture (elongation rate) was measured under the conditions of a chuck distance of 20 mm, a tensile speed of 200 mm / min, and a temperature of 23°C ± 5°C, and the results are summarized in the table. The unit is %.

[0115] <Manufacturing of laminates> (When using solvent-free adhesive) A two-component curing adhesive containing acid-modified polyolefin and epoxy resin was applied to the glossy surface of a 40 μm thick aluminum foil using a dry laminator at a rate of 3 g / m². After the solvent evaporated, a 40 μm thick unstretched polypropylene film was laminated and aged. Next, the adhesive for Example 1 was applied to the matte surface of the resulting laminated aluminum foil using a non-solvent laminator at a rate of 3 g / m². A 25 μm thick stretched polyamide film was then laminated, followed by curing (aging) at 60°C for 5 days. Next, the stretched polyamide film of the resulting laminate was coated with the adhesive for Example 1 at a rate of 3 g / m² using a non-solvent laminator, and a 12 μm thick polyethylene terephthalate film was laminated onto it. Then, curing (aging) was performed at 60°C for 5 days to obtain a laminate for evaluation. Laminates for evaluation were obtained in the same manner by using the adhesives for Examples 2, 3, and Comparative Example 2, respectively, instead of the adhesive for Example 1.

[0116] (When using solvent-based adhesives) A two-component curing adhesive containing acid-modified polyolefin and epoxy resin was applied to the glossy surface of a 40 μm thick aluminum foil at a rate of 3 g / m² using a dry laminator. After the solvent evaporated, a 40 μm thick unstretched polypropylene film was laminated and aged. Next, the adhesive for Comparative Example 1 was applied to the matte surface of the resulting laminated aluminum foil using a dry laminator at a rate of 3 g / m², and a 25 μm thick stretched polyamide film was laminated. After that, curing (aging) was performed at 60°C for 5 days. Next, the stretched polyamide film of the resulting laminate was coated with the adhesive for Comparative Example 1 at a rate of 3 g / m² using a dry laminator, and a 12 μm thick polyethylene terephthalate film was laminated onto it. After that, curing (aging) was performed at 60°C for 5 days to obtain a laminate for evaluation.

[0117] <Rating> The laminate was evaluated as follows. The results are shown in Table 2. (Adhesive strength: PET / Ny) Using Shimadzu Corporation's "Autograph AGS-J," the adhesive strength between the polyethylene terephthalate film and the stretched polyamide film of the laminates in the examples or comparative examples was measured under the conditions of a peeling speed of 50 mm / min, a peeling width of 15 mm, and a peeling pattern of T-type. The following four-stage evaluation was performed according to the magnitude of the adhesive strength. ◎: Adhesive strength consistently exceeds 3.0N (particularly excellent in practical use) ○: Adhesive strength consistently exceeds 2.0N (superior in practical use) △: Adhesive strength consistently exceeds 1.5N (practical range) ×: Adhesive strength is 1.5N or less

[0118] (Adhesive strength: Ny / AL) Using Shimadzu Corporation's "Autograph AGS-J," the adhesive strength between the stretched polyamide film and aluminum foil of the laminates in the examples or comparative examples was measured under the conditions of a peeling speed of 50 mm / min, a peeling width of 15 mm, and a peeling pattern of T-type. The following four-stage evaluation was performed according to the magnitude of the adhesive strength. ◎: Adhesive strength consistently exceeds 8.0N (particularly excellent in practical use) ○: Adhesive strength consistently exceeds 7.0N (superior in practical use) △: Adhesive strength consistently exceeds 6.0N (practical range) ×: Adhesive strength is 5.0N or less

[0119] (Moldability) Using an "Erichsen coating strength tester (electric)" manufactured by Yasuda Seiki Seisakusho Co., Ltd., the laminates of the examples or comparative examples were cut to a size of 60 x 60 mm to serve as blanks (materials to be molded). These blanks were then molded using a spherical mold with a diameter of 20 mm at 23°C ± 5°C, with the aluminum foil mat surface facing convex, to a molding height of 11 mm. Seven samples were prepared for each laminate, and the occurrence of aluminum foil breakage and delamination between layers was examined. The results were evaluated according to the following criteria and summarized in Table 1. ○: Over 80% of samples show no breakage of the aluminum foil or lifting between layers. △: The percentage of samples without aluminum foil breakage or separation between layers is between 50% and 80%. ×: Less than 50% of samples showed no breakage of the aluminum foil or lifting between layers.

[0120] (Heat resistance) Using an "Erichsen coating strength tester (electric)" manufactured by Yasuda Seiki Seisakusho Co., Ltd., the laminates of the examples or comparative examples were cut to a size of 60 x 60 mm to serve as blanks (materials to be molded). These blanks were then molded using a spherical mold with a diameter of 20 mm at 23°C ± 5°C, with the aluminum foil mat surface facing convex, to a molding height of 11 mm. Seven samples were prepared for each laminate and placed in a constant humidity chamber at 150°C for 60 seconds. After standing, the presence or absence of delamination between layers was examined. The results were evaluated according to the following criteria and summarized in Table 1. ○: The percentage of samples without separation between layers is 80% or higher. △: The percentage of samples without separation between layers is between 50% and 80%. ×: Less than 50% of samples have no separation between layers.

[0121] (Heat and moisture resistance) After heat resistance evaluation, the samples were placed in a constant temperature and humidity chamber at 85°C and 85%RH and left to stand for 72 hours. The packs were removed from the constant temperature and humidity chamber, and the presence or absence of floating between each layer was examined. The evaluation was carried out according to the following criteria, and the results are summarized in Table 1. ○: The percentage of samples without separation between layers is 80% or higher. △: The percentage of samples without separation between layers is between 50% and 80%. ×: Less than 50% of samples have no separation between layers.

[0122] [Table 2]

[0123] As shown in these results, the laminate of the present invention has excellent moldability and heat resistance. Therefore, even when heat-sealing the sealant layers together to seal the contents, for example, a packaging material can be obtained in which appearance defects such as delamination between layers are suppressed. Furthermore, even after long-term durability testing under high temperature and high humidity conditions, there is no decrease in the adhesive strength between layers, and a packaging material can be obtained in which appearance defects such as delamination between layers are suppressed. On the other hand, the laminate of the comparative example has excellent adhesive strength and moldability, but poor heat resistance. Therefore, when heat-sealing the sealant layers together to seal the contents, for example, this may cause appearance defects such as delamination between layers. It is also unsuitable for applications requiring resistance to humidity and heat.

Claims

1. It comprises a first substrate, a first adhesive layer, a second substrate, a second adhesive layer, a metal layer, and a sealant layer in this order. The first adhesive layer and the second adhesive layer are cured coating films of a two-component curable adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y), wherein the cured coating films of the polyisocyanate composition (X) and the polyol composition (Y) have an initial stress of 0.5 MPa or more and 10 MPa or less at a tensile speed of 200 mm / min and 120°C, and a breaking elongation of 5% or more at a tensile speed of 200 mm / min and 23°C ± 5°C.

2. The laminate according to claim 1, wherein the first substrate is a polyester resin film and the second substrate is a polyamide resin film.

3. The laminate according to claim 1, wherein the metal layer is aluminum foil.

4. The laminate according to claim 1, wherein the sealant layer is made of polypropylene.

5. A packaging material obtained by molding a laminate according to any one of claims 1 to 5.

6. A battery packaging material obtained by molding a laminate according to any one of claims 1 to 5.

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