Two-component curing adhesives, laminates, and packaging materials

Abstract

The present invention provides a two-component curing adhesive with excellent bonding strength between metal foil and biaxially oriented polyamide film, a laminate bonded with the adhesive, and a packaging material. [Solution] A two-component curing adhesive comprising a polyisocyanate compound (A), a polyol compound (B), and a modified silicone compound (C), wherein the polyol compound (B) comprises at least one selected from polyester polyol (B1) and polyester polyurethane polyol (B2); a laminate bonded with the adhesive; and a packaging material.

Description

Technical Field

[0001] The present invention relates to a two-component curable adhesive, 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 are required to have functions such as strength, crack resistance, and gas barrier properties in order to protect the contents from impacts received during distribution and deterioration caused by oxygen and moisture. When the contents are subjected to heat sterilization treatment, retort resistance, heat resistance, etc. are required, 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 is excellent in heat sealability and flexibility, but its oxygen barrier property is insufficient. On the contrary, a nylon film is excellent in gas barrier property but inferior in moisture resistance. For these reasons, laminates in which different polymer materials or a polymer material and a metal substrate are bonded together using an adhesive are widely used as packaging materials (Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When bonding different polymer materials or a polymer material and a metal substrate, the adhesive is required to have excellent adhesiveness to a plurality of materials having physically and chemically different properties. An object of the adhesive of the present invention is to provide a two-component curable adhesive having excellent adhesive strength between such different substrates, specifically, between a metal foil and a biaxially stretched polyamide film.

Means for Solving the Problems

[0005] In other words, the present invention relates to a two-component curing adhesive comprising a polyisocyanate compound (A), a polyol compound (B), and a modified silicone compound (C), wherein the polyol compound (B) includes at least one selected from polyester polyol (B1) and polyester polyurethane polyol (B2). [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a two-component curing adhesive with excellent adhesive strength between a metal foil and a biaxially oriented polyamide film. [Modes for carrying out the invention]

[0007] <Two-part curing adhesive> The two-component curing adhesive of the present invention is a two-component curing adhesive comprising a polyol composition (X) and a polyisocyanate composition (Y). The adhesive of the present invention will be described in detail below.

[0008] (Polyisocyanate composition (X)) (Polyisocyanate compound (A)) The polyisocyanate composition (X) contains a polyisocyanate compound (A). The polyisocyanate compound (A) 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.

[0009] 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 called polymeric MDI or crude MDI), 1,3-phenylenediisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylenediisocyanate, 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, and 4,4',4"-triphenylmethane triisocyanate.

[0010] Aromatic aliphatic diisocyanates refer to aliphatic isocyanates having one or more aromatic rings in their molecule, and include, but are not limited to, m- or p-xylylene diisocyanate (also known as XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (also known as TMXDI).

[0011] Examples of aliphatic diisocyanates include 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, and 2,4,4-trimethylhexamethylene diisocyanate, but are not limited to these.

[0012] Examples of alicyclic diisocyanates include, but are not limited to, 3-isocyanate-methyl-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), and 1,4-bis(isocyanate-methyl)cyclohexane.

[0013] As the polyisocyanate compound (A), it is preferable to use at least one selected from aromatic diisocyanates and their derivatives (compounds in which part of the NCO group is modified with carbodiimide, isocyanurate, allophanate, billet, adduct, and polyurethane polyisocyanates of the polyisocyanate), preferably a derivative of toluene diisocyanate, and preferably an adduct of toluene diisocyanate and a low molecular weight polyol. This makes it possible to create an adhesive with better heat resistance, for example, by suppressing delamination of the adhesive layer during heat sealing for bag making. It also makes it possible to improve the content resistance of the adhesive layer.

[0014] Examples of low molecular weight polyols used in the synthesis of adducts 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; Examples of the aliphatic polyols include trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol and the like.

[0015] The content of the aromatic diisocyanate and its derivative in the polyisocyanate compound (A) is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably 70% by mass or more. The total amount of the polyisocyanate compound (A) may be the aromatic diisocyanate and its derivative.

[0016] (Polyol composition (Y)) The polyol composition (Y) contains a polyol compound (B) and a modified silicone compound (C). The polyol compound (B) contains at least one selected from polyester polyol (B1) and polyester polyurethane polyol (B2) as an essential component.

[0017] (Polyester polyol (B1)) The polyester polyol (B1) is a reaction product of a composition containing a polybasic acid or its derivative and a polyhydric alcohol. Examples of the polybasic acid or its derivative used for synthesizing the polyester polyol (B1) include aliphatic polyvalent carboxylic 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, trimer acid;

[0018] alkyl esterified products of aliphatic polyvalent carboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate;

[0019] alicyclic polyvalent carboxylic 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, het acid anhydride, etc.;

[0020] aromatic polyvalent carboxylic 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 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 dianhydride, 5 - sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, etc.;

[0021] methyl esterified products of aromatic polyvalent carboxylic acids such as dimethyl terephthalic acid, dimethyl 2,6 - naphthalenedicarboxylate, etc.; and the like, and one or more of them can be used in combination.

[0022] The polyhydric alcohol used in the synthesis of polyester polyol (B1) may be a diol or a polyol with three or more functionalities. Examples of diols 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.

[0023] Modified polyetherdiols obtained by ring-opening polymerization of the aliphatic diol 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;

[0024] Lactone-based polyester polyols obtained by polycondensation reactions of the aforementioned aliphatic diol with various lactones such as lactanoides and ε-caprolactone;

[0025] Bisphenols such as bisphenol A and bisphenol F;

[0026] Examples include alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc., to bisphenols such as bisphenol A and bisphenol F.

[0027] Polyols with three or more functions include aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

[0028] Modified polyether polyols obtained by ring-opening polymerization of the aliphatic polyol with various cyclic ether linkage-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;

[0029] Examples include lactone-based polyester polyols obtained by polycondensation reactions of the aliphatic polyol with various lactones such as ε-caprolactone.

[0030] Due to their excellent adhesive properties, it is preferable that the polybasic acid contains aromatic polycarboxylic acids or alkyl esters of aromatic polycarboxylic acids (hereinafter collectively referred to as aromatic polycarboxylic acids). It is preferable that the aromatic polycarboxylic acid makes up 30% by mass or more of the polybasic acid, and more preferably 40% by mass or more. The entire amount of the polybasic acid may also be aromatic polycarboxylic acids.

[0031] The solids hydroxyl value of polyester polyol (B1) is preferably 1.0 to 40.0 mg KOH / g, more preferably 1.0 to 30.0 mg KOH / g, and even more preferably 3.0 to 25.0 mg KOH / g.

[0032] The solid content acid value of polyester polyol (B1) is not particularly limited, but is preferably 10 mgKOH / g or less as an example. The solid content acid value of polyester polyol (B1) may be 0 mgKOH / g. The hydroxyl value and acid value can be measured by the method described in JIS-K0070.

[0033] The number-average molecular weight (Mn) of polyester polyol (B1) can be adjusted as appropriate, but is preferably 3,000 to 100,000, and more preferably 3,500 to 50,000. The weight-average molecular weight (Mw) of polyester polyol (B1) is preferably 5,000 to 300,000. In this specification, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) are values ​​measured by gel permeation chromatography (GPC) under the following conditions.

[0034] 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 Developing 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.

[0035] (Polyester polyurethane polyol (B2)) Polyester polyurethane polyol (B2) is a polyol having ester bonds and urethane bonds. Polyester polyurethane polyol (B2) may be obtained by reacting a composition containing a polybasic acid, a polyhydric alcohol, and a polyisocyanate compound in a single reaction, or it may be obtained by extending a polyester polyol obtained from a polybasic acid and a polyhydric alcohol with a polyisocyanate compound. It is preferable that the polyester polyol obtained from a polybasic acid and a polyhydric alcohol is extended with a polyisocyanate compound.

[0036] The polybasic acids and polyhydric alcohols used in the synthesis of polyester polyurethane polyol (B2) can be the same as those exemplified as raw materials for polyester polyol (B1), either individually or in combination. Due to their excellent adhesive properties, it is preferable that the polybasic acid contains aromatic polycarboxylic acids or alkyl esters of aromatic polycarboxylic acids (hereinafter collectively referred to as aromatic polycarboxylic acids). It is preferable that the aromatic polycarboxylic acid makes up 30% by mass or more of the polybasic acid, and more preferably 40% by mass or more. The entire amount of the polybasic acid may also be aromatic polycarboxylic acids.

[0037] The polyisocyanate compounds used in the synthesis of polyester polyurethane polyol (B2) are the same as those exemplified in polyisocyanate compound (A), and can be used individually or in combination. Isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and the like are preferably used.

[0038] The solids hydroxyl value of polyester polyol (B2) is preferably 1.0 to 40.0 mg KOH / g, more preferably 1.0 to 30.0 mg KOH / g, and even more preferably 3.0 to 25.0 mg KOH / g.

[0039] The solid content acid value of polyester polyol (B2) is not particularly limited, but is preferably 10 mgKOH / g or less as an example. The solid content acid value of polyester polyol (B2) may be 0 mgKOH / g. The hydroxyl value and acid value can be measured by the method described in JIS-K0070.

[0040] The number-average molecular weight (Mn) of the polyester polyol (B2) can be adjusted as appropriate, but as an example, it is preferably 3,000 to 100,000, and more preferably 3,500 to 50,000.

[0041] (Other polyol compounds (B3)) The polyol compound (B) may include polyol compounds (B3) other than polyester polyol (B1) and polyester polyurethane polyol (B2). Examples of polyol (B3) include polyurethane polyols other than polyester polyurethane polyol (B1), polycarbonate polyols, and polyoxyalkylene-modified polyols. The number-average molecular weight of these polyol compounds (B3) is, for example, 300 to 50,000.

[0042] The amount of polyol compound (B3) in polyol compound (B) is preferably 20% by mass or less. In other words, the total amount of polyester polyol (B1) and polyester polyurethane polyol (B2) in polyol compound (B) is preferably 80% by mass or more. The amount of polyol compound (B3) in polyol compound (B) is preferably 10% by mass or less, and preferably 5% by mass or less. Polyol compound (B) does not have to contain polyol compound (B3).

[0043] (Modified silicone compound (C)) Modified silicone compound (C) is obtained by substituting some of the methyl groups of dimethylpolysiloxane with various organic groups. Examples of such organic groups include amino groups, epoxy groups, carboxyl groups, carbinol groups, mercapto groups, phenol groups, polyether groups, alkyl groups, aryl groups, aralkyl groups, fluoroalkyl groups, higher fatty acid ester groups, and higher fatty acid amide groups. Modified silicone compound (C) may have two or more of these organic groups.

[0044] The modified silicone compound (C) preferably comprises at least one selected from epoxy groups, carboxyl groups, carbinol groups, polyether groups, alkyl groups, aryl groups, aralkyl groups, and higher fatty acid ester groups, and more preferably comprises at least one selected from carbinol groups, polyether groups, alkyl groups, aryl groups, and aralkyl groups.

[0045] The content of the modified silicone compound (C) is preferably 0.01% by mass or more and 2% by mass or less, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more, based on the total solid content of the adhesive (polyisocyanate composition (X) and polyol composition (Y)).

[0046] (Adhesives and other components) The two-component curing adhesive of the present invention may contain components other than those described above. These other components may be included in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or they may be prepared separately and mixed with the polyisocyanate composition (X) and polyol composition (Y) immediately before application of the adhesive. Each component will be described below.

[0047] (Epoxy compound (D)) The adhesive of the present invention may also preferably contain an epoxy compound (D) having multiple glycidyl groups. This makes it possible to obtain an adhesive with even better resistance to moisture and heat. Examples of epoxy compounds (D) 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.

[0048] It is preferable to use epoxy compound (D) with a number-average molecular weight (Mn) of 300 to 2,000. It is also preferable to use epoxy compound with an epoxy equivalent weight of 150 to 1,000 g / equivalent.

[0049] The amount of epoxy compound (D) is preferably 30% by mass or less of the solid content of the polyol composition (X).

[0050] (Coupling agent (E)) The adhesive of the present invention may contain a coupling agent (E). This allows for an adhesive with superior adhesion to the substrate. The effect of the coupling agent (E) is particularly effective when the aluminum foil has not undergone chemical treatment. Examples of coupling agents (E) include silane coupling agents (E1), titanate-based coupling agents (E2), and aluminum-based coupling agents (E3). The coupling agent (E) may be added to the polyisocyanate composition (X) or to the polyol composition (Y). It may also be added when mixing the polyisocyanate composition (X) and the polyol composition (Y).

[0051] Examples of silane coupling agents (E1) include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; isocyanatesilanes such as 3-isocyanatetopropyltrimethoxysilane and 3-isocyanatetopropyltriethoxysilane; and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and glycidoxyoctyltrimeth Examples of silane coupling agents include epoxysilanes such as xysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, octenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane; polymer-type silane coupling agents such as polymer-type epoxysilanes in which multiple alkoxysilyl groups and multiple epoxy groups are introduced into the polymer skeleton, and polymer-type aminosilanes in which multiple alkoxysilyl groups and multiple amino groups are introduced into the polymer skeleton; and hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane. These silane coupling agents (E1) can be used alone or in combination of two or more types.

[0052] Examples of titanate-based coupling agents (E2) include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxititanium.

[0053] Examples of aluminum-based coupling agents (E3) include acetalkoxyaluminum diisopropylate.

[0054] The amount of coupling agent (E) 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 solid content of polyol composition (Y). Furthermore, the content of coupling agent (E) 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 solid content of polyol composition (Y).

[0055] (Tackifier (G)) The adhesive of the present invention may contain a tackifier (G). The tackifier (G) may be added to the polyisocyanate composition (X), to the polyol composition (Y), or added when mixing them. Examples of tackifiers (G) 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-type tackifiers. These may be used individually or in combination of two or more types. While tackifiers with various softening points can be obtained mainly depending on their molecular weight, a softening point of 10 to 160°C is preferable from the viewpoint of compatibility when mixed with other resins constituting the polyol composition (X), color tone, and thermal stability. It is preferable to use it in an amount of 1 to 30 parts by mass (solids) per 100 parts by mass of the solids content of the resin constituting the polyol composition (X), and more preferably in an amount of 3 to 20 parts by mass (solids).

[0056] (Phosphoric acids or their derivatives (H)) The adhesive of the present invention may contain phosphoric acids or their derivatives (H). This improves initial adhesion and suppresses problems such as tunneling. Phosphoric acids or their derivatives (H) may be added to the polyisocyanate composition (X) or to the polyol composition (Y). They may also be added when mixing these.

[0057] Examples of phosphoric acids or their derivatives (H) include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and subphosphoric acid; condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid; and monomethyl orthophosphoric acid, monoethyl orthophosphoric acid, monopropyl orthophosphoric acid, monobutyl orthophosphoric acid, mono-2-ethylhexyl orthophosphoric acid, monophenyl orthophosphoric acid, monomethyl phosphorous acid, monoethyl phosphorous acid, monopropyl phosphorous acid, monobutyl phosphorous acid, mono-2-ethylhexyl phosphorous acid, monophenyl orthophosphoric acid, and ortholin Examples include mono- and diesterified compounds of di-2-ethylhexyl acid, diphenyl orthophosphate dimethyl phosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, diphenyl phosphate, mono- and diesterified compounds of condensed phosphoric acid and alcohols, for example, those obtained by adding epoxy compounds such as ethylene oxide or propylene oxide to the above phosphoric acids, for example, epoxy phosphate esters obtained by adding the above phosphoric acids to aliphatic or aromatic diglycidyl ethers, and two or more of these can be used in combination.

[0058] The adhesive of the present invention may be in either a solvent-type or solvent-free form. In the case of a solvent-type adhesive, at least one of the polyisocyanate composition (X) or polyol composition (Y) contains an organic solvent such as 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, with each of the above-mentioned components dissolved in the organic solvent. These organic solvents may be those used as reaction media during the production of each of the above-mentioned components, or they may be added separately.

[0059] In the case of solvent-free adhesives, they substantially do not contain the organic solvents mentioned above. However, if the organic solvents used as reaction media during the manufacturing of each component of the adhesive are not completely removed and remain in the product, it is understood that the adhesive substantially does not contain organic solvents.

[0060] In addition, the adhesive of the present invention may contain various additives such as ultraviolet absorbers, antioxidants, silicone-based additives, fluorine-based additives, rheology control agents, defoaming agents, antistatic agents, and anti-fogging agents.

[0061] In the adhesive of the present invention, the mixing ratio of the polyisocyanate composition (X) and the polyol composition (Y) is preferably such that the ratio [NCO] / [OH] of the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (X) to the total number of moles of hydroxyl groups [OH] contained in the polyol composition (Y) is in the range of 1.0 to 10.0, and more preferably 2.0 to 5.0.

[0062] <Laminate> The adhesive of the present invention is particularly suitable for use in the manufacture of laminates comprising a metal foil and a biaxially oriented polyamide film bonded together with the adhesive, but is not limited thereto, and can be suitably used in the manufacture of various laminates. The laminate of the present invention is obtained by bonding a first substrate and a second substrate with the adhesive of the present invention. The method for manufacturing the laminate is not particularly limited, but as an example, if the two-component curing adhesive is solvent-type, the adhesive of the present invention is applied to either the first or second substrate by gravure coating, roll coating, etc., the organic solvent is evaporated, and then the other substrate is bonded. If the adhesive is solvent-free, the two-component curing adhesive is applied to either the first or second substrate, and then the other substrate is bonded (without the step of evaporating the organic solvent in the adhesive). The temperature of the laminating roll when bonding the substrates is, as an example, 40°C to 120°C. It is preferable to bond the substrates at a temperature of 40 to 100°C to obtain a laminate with better moldability. The pressure of the laminating roll is 3 to 300 kg / cm². 2This is preferable. After bonding the substrates together, the adhesive is cured by aging at room temperature to 100°C, more preferably 40 to 100°C for 2 days to 2 weeks to obtain a laminate. The amount of adhesive applied can be adjusted as appropriate, but as an example, 1.5 g / m² is used. 2 ~10.0g / m 2 That is the case.

[0063] There are no particular restrictions on the substrate used, and one can be appropriately selected according to the application. For example, for food packaging, examples include polyethylene terephthalate (PET) film, polystyrene film, biaxially oriented polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE: biaxially oriented polyethylene film), polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), ethylene vinyl alcohol copolymer, and gas barrier heat-seal films such as polyolefin films, polyvinyl alcohol films, and ethylene-vinyl alcohol copolymer films, which have an olefin-based heat-sealable resin layer on one or both sides of a gas barrier resin such as polyvinyl alcohol.

[0064] Furthermore, it is preferable to use a film formed from materials containing biomass-derived components. Biomass films are sold by various companies, and for example, sheets listed in the biomass certified product list provided by the Japan Organic Resources Association can be used.

[0065] A well-known example of a film made from biomass-derived ethylene glycol is derived from ethanol produced from biomass (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by conventionally known methods, such as a method that produces ethylene glycol via ethylene oxide from biomass ethanol. Alternatively, commercially available biomass ethylene glycol may be used; for example, the biomass ethylene glycol commercially available from India Glycol can be suitably used.

[0066] Alternatively, products using biomass raw materials, distinguished by their biomass plasticity as defined by ISO 16620 or ASTM D6866, are also available. Radioactive carbon-14C exists in the atmosphere at a rate of 1 in 10¹² atoms, and this rate does not change even in atmospheric carbon dioxide. Therefore, this rate does not change in plants that fix carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins contains radioactive carbon-14C. In contrast, the carbon in fossil fuel-derived resins contains almost no radioactive carbon-14C. Therefore, by measuring the concentration of radioactive carbon-14C in the resin using an accelerator mass spectrometer, the proportion of plant-derived resin in the resin, i.e., the biomass plasticity, can be determined. Examples of plant-derived low-density polyethylene (PPE) biomass plastics with a biomass plastic content of 80% or more, preferably 90% or more, as defined by ISO 16620 or ASTM D6866, include Braskem's product names "SBC818," "SPB608," "SBF0323HC," "STN7006," "SEB853," and "SPB681," and films made from these materials can be suitably used.

[0067] The film may be stretched. A common stretching method involves melting and extruding the resin into a sheet using methods such as extrusion film formation, followed by simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching, followed by transverse stretching. Specifically, a method combining longitudinal stretching using the speed difference between rolls and transverse stretching using a tenter is frequently used.

[0068] Various surface treatments, such as flame treatment or corona discharge treatment, may be applied to the film surface as needed to ensure that an adhesive layer free from defects such as film breakage or repulsion is formed.

[0069] Alternatively, films made by laminating metals such as aluminum, metal oxides such as silica or alumina, barrier films containing a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride, or metal foils such as aluminum foil, copper foil, or stainless steel foil may be used. By using such films, a laminate can be made that has barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic substances (fragrances), etc.

[0070] As for the paper, any known paper substrate can be used without particular limitation. Specifically, it is manufactured using known papermaking natural fibers such as wood pulp and papermaking machines, but the papermaking conditions are not particularly specified. Examples of natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal hemp pulp, and flax pulp, and pulps that have been chemically modified. As for the type of pulp, chemical pulps produced by sulfate pulping, acidic, neutral, and alkaline sulfite pulping, soda salt pulping, etc., as well as gland pulp, chemigland pulp, thermomechanical pulp, etc. can be used. In addition, various commercially available fine papers, coated papers, backing papers, impregnated papers, cardboard, and paperboard can also be used.

[0071] More specifically, the configuration of the laminate is as follows: (1) Substrate 1 / Adhesive layer 1 / Sealant film (2) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited unstretched film (3) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretched film (4) Transparent vapor-deposited stretched film / adhesive layer 1 / sealant film (5) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Sealant film (6) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretched film / Adhesive layer 2 / Sealant film (7) Substrate 1 / Adhesive layer 1 / Transparent vapor-deposited stretched film / Adhesive layer 2 / Sealant film (8) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Sealant film (9) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Metal layer / Adhesive layer 3 / Sealant film (10) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Substrate 2 / Adhesive layer 3 / Sealant film Examples include, but are not limited to, those listed above.

[0072] Examples of substrates 1 used in composition (1) include MDOPE film, OPE film, OPP film, PET film, nylon film, and paper. Alternatively, a substrate 1 coated with a coating for purposes such as improving gas barrier properties or ink receptivity when providing the printing layer described later may be used. Commercially available coated substrate films 1 include K-OPP film, K-PET film, and K-nylon film. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealant films include CPP film, LLDPE film, easy-open heat-seal film, and gas-barrier heat-seal film. The printing layer may be provided on the side of the substrate 1 facing the adhesive layer 1 (or, if a coated substrate film 1 is used, on the side of the coating layer facing the adhesive layer 1) or on the side opposite to the adhesive layer 1. The printing layer is formed using various printing inks such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink, using general printing methods conventionally used for printing on polymer films and paper.

[0073] Examples of substrate 1 used in configurations (2) and (3) include MDOPE film, OPE film, OPP film, PET film, paper, etc. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of unstretched metal-deposited films include CPP film, LLDPE film, VM-CPP film, VM-LLDPE film, etc., which are gas barrier heat seal films with metal deposition of aluminum or the like. Examples of stretched metal-deposited films include VM-MDOPE film, VM-OPE film, VM-OPP film, etc., which are MDOPE film, OPE film, or OPP film with metal deposition of aluminum or the like. A printed layer may be provided on any surface of the substrate 1 in the same manner as in configuration (1).

[0074] Examples of transparent vapor-deposited stretched films used in configuration (4) include MDOPE films, OPE films, OPP films, PET films, nylon films, etc., on which silica or alumina vapor deposition has been applied. Films with a coating applied to the vapor-deposited layer may also be used for purposes such as protecting the inorganic vapor-deposited layer of silica or alumina. The adhesive layer 1 is a cured coating film of the adhesive of the present invention. The sealant film is the same as that of configuration (1). A printed layer may be provided on the side of the transparent vapor-deposited stretched film facing the adhesive layer 1 (or, if a film with a coating applied to the inorganic vapor-deposited layer is used, on the side of the coating layer facing the adhesive layer 1). The method for forming the printed layer is the same as in configuration (1).

[0075] Examples of substrate 1 used in configuration (5) include PET film and paper. Examples of substrate 2 include nylon film. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of sealant film are the same as those in configuration (1). A printed layer may be provided on any surface of substrate 1 in the same manner as in configuration (1).

[0076] The base material 1 of configuration (6) is the same as that of configurations (2) and (3). Examples of metal vapor-deposited stretched films include VM-MDOPE film, VM-OPE film, VM-OPP film, and VM-PET film, which are obtained by vapor deposition of aluminum or other metal onto MDOPE film, OPE film, OPP film, or PET film. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of sealant films are the same as those of configuration (1). A printed layer may be provided on any surface of the base material 1 in the same manner as in configuration (1).

[0077] Examples of the substrate 1 in configuration (7) include PET film and paper. Examples of the transparent vapor-deposited stretched film include those the same as in configuration (4). At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those the same as in configuration (1). A printed layer may be provided on any surface of the substrate 1 in the same manner as in configuration (1).

[0078] Examples of the base material 1 in configuration (8) include PET film and paper. Examples of the metal layer include aluminum foil. At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film are the same as those in configuration (1). A printed layer may be provided on any surface of the base material 1 in the same manner as in configuration (1).

[0079] Examples of base material 1 in configurations (9) and (10) include PET film and paper. Examples of base material 2 include nylon film. Examples of metal layers include aluminum foil. At least one layer of adhesive layers 1, 2, and 3 is a cured coating of the adhesive of the present invention. Examples of sealant films are the same as those in configuration (1). A printed layer may be provided on any surface of base material 1 in the same manner as in configuration (1).

[0080] The laminate of the present invention may further include other films or substrates in addition to the above-described configurations (1) to (10). As other substrates, in addition to the stretched film, unstretched film, and transparent vapor-deposited film described above, porous substrates such as paper, wood, and leather, as described later, may also be used. The adhesive used when bonding the other substrates may be the adhesive of the present invention or not.

[0081] The "other layer" may contain known additives and stabilizers, such as antistatic agents, easy-adhesion coating agents, plasticizers, lubricants, and antioxidants. The "other layer" may also have its surface pretreated by corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc., to improve adhesion when laminated with other materials.

[0082] The laminate of the present invention can be suitably used in a variety of applications, such as packaging materials for food, pharmaceuticals, and household goods; lids; paper tableware such as paper straws, paper napkins, paper spoons, paper plates, and paper cups; protective wall materials; roofing materials; solar panel materials; battery packaging materials; window materials; outdoor flooring materials; lighting protection materials; automotive components; signs; stickers and other outdoor industrial applications; decorative sheets used in injection molding simultaneous decoration methods; and packaging materials for laundry detergents, kitchen detergents, bath detergents, bath soaps, liquid shampoos, liquid conditioners, and the like.

[0083] <Packaging material> The laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting food, pharmaceuticals, and other products. When used as a multilayer packaging material, the layer configuration may be changed depending on the contents, usage environment, and usage form. Furthermore, the packaging of the present invention may be appropriately provided with an easy-open treatment or resealing means.

[0084] As an example of a specific embodiment of the packaging material of the present invention, a packaging material made by forming a bag from the laminate described above can be cited. The laminate is folded or overlapped so that the inner layers (sealant film surfaces) face each other, and the peripheral edges are heat-sealed to form a bag. Methods for forming the bag include heat sealing methods such as side seal type, two-side seal type, three-side seal type, four-side seal type, envelope seal type, gusset seal type, pleated seal type, flat-bottom seal type, square-bottom seal type, gusset type, and other heat-seal types. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage method. Self-standing packaging materials (standing pouches) are also possible. Known heat sealing methods include bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal.

[0085] Products using the packaging material of the present invention are manufactured by filling such packaging materials with contents through their openings and then heat-sealing the openings. Examples of contents that can be filled include, for example, food products such as rice crackers, bean snacks, nuts, biscuits / cookies, wafers, marshmallows, pies, semi-baked cakes, candies, and snack foods; staple foods such as bread, instant noodles, dried noodles, pasta, aseptically packaged rice, rice porridge, packaged mochi, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, enoki mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potato products; processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef; and fish ham. Examples of processed seafood products include sausages, processed seafood products, fish cakes, seaweed, preserved foods, dried bonito flakes, salted seafood, smoked salmon, and spicy cod roe; fruits such as peaches, oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; frozen and chilled prepared foods such as hamburgers, meatballs, fried seafood, dumplings, and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; liquid seasonings; retort curry; and pet food.

[0086] Furthermore, as a non-food product, it can be used as a packaging material for various items such as cigarettes, disposable hand warmers, pharmaceuticals such as intravenous fluid packs, liquid laundry detergent, liquid dish soap, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotions and emulsions, vacuum insulation materials, and batteries.

[0087] Another example of a specific embodiment of the packaging material of the present invention is to form the above-described laminate to provide one or more recesses (pockets) and then bond another laminate (for example, a lid material made of aluminum foil coated with a heat sealant, or the above-described laminate that is not molded) to it; or to prepare two laminates of the present invention each with one or more recesses, align these recesses, and heat seal the heat seal layers together. The shape of the recess is not particularly limited and may be square, circular, elliptical, or any other shape. Examples of molding methods include, but are not limited to, the flat plate pneumatic molding method, the plug-assisted pressure molding method, the drum-type vacuum molding method, and the plug molding method.

[0088] Such packaging materials are suitably used, for example, as packaging materials for pet food, pharmaceuticals, cosmetics such as lotions and emulsions, and batteries. [Examples]

[0089] 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.

[0090] <Synthesis of polyol compound (B)> (Synthesis Example 1) Synthesis of polyester polyurethane polyol (B2-1) In a polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 227.5 parts isophthalic acid, 204.8 parts sebacic acid, 42.6 parts ethylene glycol, 199.0 parts neopentyl glycol, and 0.15 parts titanium tetraisopropoxide (hereinafter abbreviated as TIPT) 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 240°C. When the acid value reached 1.5 mg KOH / g, the pressure was reduced to 10 mmHg or less and held for 1.5 hours to complete the esterification reaction and obtain the intermediate polyester polyol (B2'-1).

[0091] To 100 parts of the obtained intermediate polyester polyol (B2'-1), 4.5 parts of isophorone diisocyanate were added, and the mixture was heated to 90°C to carry out the urethane reaction until the free NCO groups were substantially eliminated, thereby obtaining polyester polyurethane polyol (B2-1). Dilution with ethyl acetate was used to obtain a solution of polyester polyurethane polyol (B2-1) with a non-volatile content of 65.5%.

[0092] (Synthesis Example 2) Synthesis of Polyester Polyurethane Polyol (B2-2) In a polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, and moisture separator, 105 parts terephthalic acid, 105 parts isophthalic acid, 53.83 parts dimer acid (Tsunodyme 216, manufactured by Tsukuno Oleochemicals Co., Ltd., AN=194 mgKOH / g), 103.26 parts adipic acid, 48.94 parts ethylene glycol, 98.12 parts neopentyl glycol, 48.94 parts 1,6-hexanediol, and 0.15 parts TIPT 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 240°C. When the acid value reached 1.5 mgKOH / g, the pressure was reduced to 10 mmHg or less and maintained for 1.5 hours to complete the esterification reaction and obtain the intermediate polyester polyol (B2'-2).

[0093] 100 parts of the intermediate polyester polyol (B2'-2), which had been heated to 100°C, were charged into a reactor equipped with a condenser and diluted and dissolved with 43 parts of ethyl acetate. Then, at 80°C, 3.2 parts of isophorone diisocyanate and 0.02 parts of iron neodecanoate were added, and the urethane reaction was carried out until the NCO content was 0.01% or less as measured by NCO. After that, the solution was further diluted with ethyl acetate to obtain an ethyl acetate solution of polyester polyurethane polyol (B2'-2).

[0094] <Preparation of two-component curing adhesive> (Example 1) A polyol composition (Y-1) was prepared by thoroughly stirring 90 parts of a solution of polyester polyol (B2-1) and 0.6 parts of a modified silicone compound (C-1). As the polyisocyanate composition (X), 12 parts of trimethylolpropane adduct of toluene diisocyanate (indicated as polyisocyanate compound (A) in the table; NCO%: 13.3, non-volatile content 75%) were mixed with ethyl acetate to a non-volatile content of 25%, and the mixture was thoroughly stirred to prepare the two-component curing adhesive of Example 1.

[0095] (Examples 2) to (Examples 6) A two-component curing adhesive was prepared in the same manner as in Example 1, except that the modified silicone compound (C), epoxy compound (D), silane coupling agent (E), and their proportions were changed as shown in Table 1. The details of the modified silicone compound (C), epoxy compound (D), and silane coupling agent (E) in the table are as follows. The values ​​in the table include organic solvents (except for ethyl acetate used to dilute the solid content of the adhesive to 25%).

[0096] Modified silicone compound (C-1): Dimethylpolysiloxane having an aralkyl group (100% non-volatile content) Modified silicone compound (C-2): Dimethylpolysiloxane having polyether groups and carbinol groups (100% non-volatile content) Epoxy compound (D): Bisphenol A type epoxy resin (70% non-volatile content, 475 g / eq epoxy equivalent) Silane coupling agent (E): Glycidylpropyltrimethoxysilane (100% non-volatile content)

[0097] (Comparative Example 1) to (Comparative Example 7) Two-component curing adhesives for Comparative Examples 1 to 7 were prepared in the same manner as in the Examples, except that modified silicone compound (C) was either omitted or replaced with other additives, and the amounts were as shown in Table 2. The non-volatile content of Surfinol 420 and 440, used as other additives, was 100%, and the non-volatile content of dimethylpolysiloxane was also 100%.

[0098] <Manufacturing of laminates> (Example 1) Apply the adhesive from Example 1 to the matte surface of a 40 μm thick aluminum foil using a dry laminator at a rate of 4 g / m². 2 The material was coated with (solids), the solvent was evaporated, and then it was combined with a 25 μm thick stretched polyamide film and passed through a laminating roll at 100°C to bond them together. Next, 4 g / m² of the adhesive from Example 1 was applied to the glossy surface of the aluminum foil using a dry laminator. 2 After applying the material and allowing the solvent to evaporate, the laminate was passed through a 100°C laminating roll together with a 60 μm thick polyvinyl chloride film to bond them together, and then aged at 80°C for 4 days to cure the adhesive and obtain the laminate of Example 1.

[0099] (Examples 2) to (Examples 6), (Comparative Example 1) to (Comparative Example 7) A laminate was obtained in the same manner as in Example 1, except that the adhesives of Examples 2-6 and Comparative Examples 1-7 were used instead of the adhesive of Example 1.

[0100] <Rating> (Adhesive strength) Using Shimadzu Corporation's "Autograph AGS-J," the adhesive strength between polyamide film and aluminum foil was evaluated according to the following criteria under the conditions of a peeling speed of 50 mm / min, a peeling width of 15 mm, and a T-shaped peeling pattern, and the results are summarized in Tables 1 and 2. 5:10.0N / 15mm or more 4: 9.0N / 15mm or more, less than 10.0N / 15mm 3: 8.0N / 15mm or more, less than 9.0N / 15mm 2: 7.5N / 15mm or more, 8.0N / 15mm or less 1:7.5N / less than 15mm

[0101] [Table 1]

[0102] [Table 2]

Claims

1. Polyisocyanate compound (A) and, Polyol compound (B) and A modified silicone compound (C) is included, A two-component curing adhesive, wherein the polyol compound (B) comprises at least one selected from polyester polyol (B1) and polyester polyurethane polyol (B2).

2. The two-component curing adhesive according to claim 1, wherein the content of the modified silicone compound (C) is 0.01% by mass or more and 2% by mass or less of the total nonvolatile content of the two-component curing adhesive.

3. The two-component curing adhesive according to claim 1, wherein the modified silicone compound (C) comprises at least one selected from epoxy groups, carboxyl groups, carbinol groups, polyether groups, alkyl groups, aryl groups, aralkyl groups, and higher fatty acid ester groups.

4. A two-component curing adhesive according to claim 1, comprising an epoxy compound (D).

5. A two-component curing adhesive according to claim 1, comprising a silane coupling agent (E).

6. The two-component curing adhesive according to claim 1, wherein the polyisocyanate compound (A) comprises a derivative of toluene diisocyanate.

7. It includes a first substrate, a second substrate, and an adhesive layer for bonding the first substrate and the second substrate, A laminate in which the adhesive layer is a cured coating film of a two-component curable adhesive according to any one of claims 1 to 6.

8. The laminate according to claim 7, wherein the first substrate is a polyamide resin film and the second substrate is a metal foil.

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