Adhesive, laminate, and packaging material

Abstract

Provided is a solvent-free two-component curable adhesive having excellent adhesive strength after a retort treatment even when a substrate having a metal foil such as an aluminum foil or a metal deposited layer of aluminum or the like is bonded to a plastic film.　This solvent-free two-component curable adhesive comprises a polyisocyanate composition (X) and a polyol composition (Y), wherein: the polyisocyanate composition (X) contains a polyurethane polyisocyanate (A1), which is a reaction product of a polyisocyanate (l) and a polyester polyol (m), and an acid anhydride (B); the acid value derived from the acid anhydride (B) in the polyisocyanate composition (X) is 1-100 mg KOH / g; the content of a diisocyanate monomer in the polyisocyanate composition (X) is at most 0.1 mass%; and the polyol composition (Y) contains a polyester polyol (C1).

Description

Adhesives, laminates, packaging materials

[0001] The present invention relates to a two-component curing adhesive, a laminate, and a packaging material.

[0002] Laminates used for various packaging materials, labels, etc. are imparted with design, functionality, storage stability, convenience, transport resistance, etc. by laminating a wide variety of substrates such as plastic films, metal foils, paper, etc. Packaging materials obtained by molding such laminates into bags are used as packaging materials in various fields, including food, pharmaceuticals, detergents, etc.

[0003] Conventionally, laminate films have mainly been obtained by a dry lamination method in which a two-component curing adhesive in which a polyisocyanate compound and a polyol compound are dissolved in a volatile organic solvent is applied to a film, the organic solvent is volatilized during passage through an oven, and another film is laminated. However, in recent years, from the viewpoint of reducing environmental load and improving the working environment, two-component curing solventless adhesives in which the polyisocyanate compound and the polyol compound do not contain volatile organic solvents have been attracting attention (Patent Document 1, Patent Document 2).

[0004] JP 2014-159548 A JP 2001-172602 A

[0005] When such a solventless, two-component curing adhesive is used to bond a plastic film to a metal foil such as an aluminum foil or a substrate having a metal vapor-deposited layer of aluminum or the like, the adhesive strength after retort treatment may be poor, particularly when the contents contain an acidic component such as vinegar.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solventless, two-component curing adhesive that exhibits excellent adhesive strength after retort treatment even when bonding a plastic film to a substrate having a metal foil such as aluminum foil or a metal vapor-deposited layer of aluminum or the like. Another object of the present invention is to provide a solventless, two-component curing adhesive that exhibits excellent adhesive strength after retort treatment even when the contents contain a large amount of an acidic component.

[0007] Specifically, the present invention relates to a two-component curing solventless adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y), wherein the polyisocyanate composition (X) comprises a polyurethane polyisocyanate (A1) which is a reaction product of a polyisocyanate (l) and a polyester polyol (m), and an acid anhydride (B), wherein the acid value derived from the acid anhydride (B) in the polyisocyanate composition (X) is 1 mgKOH / g or more and 100 mgKOH / g or less, the content of diisocyanate monomers in the polyisocyanate composition (X) is 0.1 mass% or less, and the polyol composition (Y) comprises a polyester polyol (C1).

[0008] According to the present invention, it is possible to provide a solventless two-component curing adhesive that exhibits excellent adhesive strength after retort treatment even when bonding a plastic film to a substrate having a metal foil such as aluminum foil or a metal vapor-deposited layer of aluminum or the like.

[0009] <Adhesive> (Polyisocyanate Composition (X)) (Polyurethane Polyisocyanate (A1)) The polyisocyanate composition (X) used in the two-component curing adhesive of the present invention contains a polyurethane polyisocyanate (A1), which is a reaction product of a polyisocyanate (1) and a polyol (m). The polyisocyanate (1) used in the synthesis of the polyurethane polyisocyanate (A1) is not particularly limited, and conventionally known aromatic diisocyanates, araliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and biuret, nurate, adduct, allophanate, carbodiimide-modified, uretdione-modified, etc. of these diisocyanates can be used. One or more polyisocyanates can be used in combination.

[0010] Examples of aromatic diisocyanates include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (also known as MDI), polymethylene polyphenyl polyisocyanate (also known as polymeric MDI or crude MDI), 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate (also known as PPDI), 2,4-tolylene diisocyanate, and the like. Examples of the isocyanate include, but are not limited to, 2,6-tolylene diisocyanate (also known as TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, tolidine diisocyanate (also known as TODI), dianisidine diisocyanate, naphthalene diisocyanate (also known as NDI), 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

[0011] The araliphatic diisocyanate means an aliphatic isocyanate having one or more aromatic rings in the molecule, and examples thereof 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), and the like.

[0012] Examples of aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate (also known as PDI), 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate (also known as LDI), but are not limited to these.

[0013] Examples of alicyclic diisocyanates include 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'-methylenebiscyclohexyl isocyanate (also known as hydrogenated MDI or HMDI), 1,3-bis(isocyanatomethyl)cyclohexane (also known as hydrogenated XDI or HXDI), hydrogenated TMXDI, and norbornane diisocyanate (also known as NBDI), but are not limited to these.

[0014] The polyisocyanate (l) is preferably at least one selected from aromatic diisocyanates, araliphatic diisocyanates, and alicyclic diisocyanates, and more preferably at least one selected from toluene diisocyanate, xylene diisocyanate, and isophorone diisocyanate. Since MDI is highly reactive and may cause side reactions in the step of dissolving an acid anhydride at high temperatures, it is preferable that the polyisocyanate does not contain MDI.

[0015] The polyol (m) is not particularly limited, and examples thereof include glycols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol;

[0016] Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol; bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimer diol;

[0017] polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of a polymerization initiator such as glycol, trifunctional or tetrafunctional aliphatic alcohol, etc.;

[0018] polyester polyols, which are reaction products of polyhydric alcohols such as glycols and trifunctional or tetrafunctional aliphatic alcohols with polycarboxylic acids; polyether polyester polyols, which are reaction products of polyether polyols with polycarboxylic acids;

[0019] Examples of the polyol include: polyurethane polyols, which are reaction products of polyhydric alcohols such as glycols and trifunctional or tetrafunctional aliphatic alcohols with polyisocyanates; polyether polyurethane polyols, which are reaction products of polyether polyols with polyisocyanates; and polyester polyurethane polyols, which are reaction products of polyester polyols with polyisocyanates. These polyols can be used alone or in combination of two or more.

[0020] Examples of polycarboxylic acids used in the synthesis of polyester polyols include aromatic polybasic 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, and tetrabromophthalic anhydride; and methyl esters of aromatic polybasic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate.

[0021] Aliphatic polybasic acids such as malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, and itaconic acid; alkyl esters of aliphatic polybasic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0022] Examples of the alicyclic polybasic acids include 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-1,2-anhydride, himic acid anhydride, and HET acid anhydride, and these may be used alone or in combination of two or more.

[0023] The polycarboxylic acid preferably includes an aromatic polycarboxylic acid. The amount of the aromatic polycarboxylic acid in the polycarboxylic acid can be appropriately adjusted depending on the purpose, but is preferably 20% by mass or more, and more preferably 30% by mass or more, for example. The total amount of the polycarboxylic acid may be aromatic polycarboxylic acid.

[0024] As the polyisocyanate used in the synthesis of polyurethane polyol, the same ones as those exemplified as polyisocyanate (l) can be used alone or in combination.

[0025] The polyol (m) is preferably at least one selected from polyester polyols and polyether polyols.

[0026] The molecular weight of the polyol (m) is preferably 300 g / mol or more and 3000 g / mol or less, and more preferably 400 g / mol or more and 2000 g / mol or less.

[0027] The polyurethane polyisocyanate (A1) can be obtained by reacting the polyisocyanate (1) exemplified above with a polyol (m) under conditions in which the isocyanate groups of the polyisocyanate (m) are in excess relative to the active hydrogen groups of the polyester polyol (m). The equivalent ratio of the isocyanate groups to the active hydrogen groups [NCO] / [active hydrogen groups] can be appropriately adjusted, but is, for example, from 2.0 to 20.0.

[0028] (Isocyanate Derivative (A2)) The polyisocyanate composition (X) used in the present invention may contain an isocyanate derivative (A2) other than the polyurethane polyisocyanate (A1). Examples of such an isocyanate derivative (A2) include biuret, nurate, allophanate, carbodiimide-modified, and uretdione-modified diisocyanate monomers such as aromatic diisocyanates, araliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, which are exemplified as raw materials for the polyurethane polyisocyanate (A1), and polyurethane polyisocyanates.

[0029] When the polyisocyanate composition (X) contains the isocyanate derivative (A2), the proportion of the polyurethane polyisocyanate (A1) in the isocyanate group-containing compounds (the polyurethane polyisocyanate (A1) and the isocyanate derivative (A2)) in the polyisocyanate composition (X) is preferably 30 mass% or more, which allows the composition to have excellent adhesion to metal substrates such as aluminum foils and aluminum vapor-deposited films.

[0030] (Acid Anhydride (B)) Examples of the acid anhydride (B) include cyclic aliphatic acid anhydrides, aromatic acid anhydrides, unsaturated carboxylic acid anhydrides, etc., and these may be used alone or in combination of two or more. More specifically, for example, maleic acid anhydride, phthalic acid anhydride, trimellitic acid anhydride, pyromellitic acid anhydride, benzophenonetetracarboxylic acid anhydride, dodecenylsuccinic acid anhydride, polyadipic acid anhydride, polyazelaic acid anhydride, polysebacic acid anhydride, poly(ethyloctadecanedioic acid) anhydride, poly(phenylhexadecanedioic acid) anhydride, tetrahydrophthalic acid anhydride, methyltetrahydrophthalic acid anhydride, methylhexahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, methylhimic acid anhydride, trialkyltetrahydrophthalic acid anhydride, anhydride, methylcyclohexene dicarboxylic acid anhydride, methylcyclohexene tetracarboxylic acid anhydride, ethylene glycol bistrimellitate dianhydride, HET acid anhydride, Nadic acid anhydride, methylnadic acid anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dianhydride, 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic acid dianhydride, and the like.

[0031] The acid anhydride (B) may be any of the above compounds modified with glycol. Examples of glycols that can be used for modification include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol; and polyether glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Furthermore, copolymer polyether glycols of two or more of these glycols and / or polyether glycols may also be used.

[0032] Alternatively, among the compounds described above as the acid anhydride (B), a homopolymer or copolymer of a compound having a polymerizable unsaturated group, such as maleic anhydride, may be used. Examples of compounds copolymerizable with a compound having an acid anhydride group and a polymerizable unsaturated group include α-olefins such as ethylene, propylene, 1,3-butadiene, and cyclopentylethylene; vinyl compounds having an aromatic ring, such as styrene, 1-ethynyl-4-methylbenzene, divinylbenzene, 1-ethynyl-4-methylethylbenzene, benzonitrile, acrylonitrile, p-tert-butylstyrene, 4-vinylbiphenyl, 4-ethynylbenzyl alcohol, 2-ethynylnaphthalene, and phenanthrene-9-ethynyl; and fluoroolefins such as vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene. These compounds may be used alone or in combination of two or more. It is preferable to use styrene and p-tert-butylstyrene, which are vinyl compounds having an aromatic ring.

[0033] The acid anhydride (B) used in the present invention is preferably a non-aromatic carboxylic acid anhydride. This prevents a significant loss of productivity in the step of dissolving the acid anhydride, and can suppress a decrease in adhesive strength even after retort treatment. In this specification, the term "non-aromatic carboxylic acid anhydride" refers to an anhydride in which the anhydride ring is not directly bonded to an aromatic ring, i.e., a cyclic aliphatic acid anhydride, an unsaturated carboxylic acid anhydride, a glycol-modified product of these acid anhydrides, or a copolymer with a compound having a polymerizable unsaturated group.

[0034] The acid anhydride (B) is used in such a range that the acid value derived from the acid anhydride (B) in the polyisocyanate composition (X) is 1 mgKOH / g or more and 100 mgKOH / g or less, and more preferably 5 mgKOH / g or more and 70 mgKOH / g or less. The acid value derived from the acid anhydride (B) may be determined by calculation of the acid value when the anhydride ring is opened from the structure and amount of the acid anhydride (B) added, or may be measured using FT-IR.

[0035] When measuring using FT-IR, it is a value calculated according to the following formula using the coefficient (f) obtained from a calibration curve prepared using a chloroform solution of the acid anhydride (B), the absorbance (I) of the stretching peak of the anhydride ring of the acid anhydride (B) in the polyisocyanate composition (X), and the absorbance (II) of the stretching peak of the carbonyl group when the anhydride ring of the acid anhydride (B) is ring-opened, and unless otherwise specified, the unit is mgKOH / g. In the following formula, the molecular weight of potassium hydroxide is 56.11.

[0036]

[0037] The polyisocyanate composition (X) used in the present invention has a content of diisocyanate monomers having a molecular weight of 280 or less, i.e., diisocyanate monomers such as aromatic diisocyanates, araliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, which are exemplified as raw materials for the polyurethane polyisocyanate (A1), of 0.1% by mass or less.

[0038] The content of diisocyanate monomer can be measured by gas chromatography using an internal standard, for example, in accordance with ASTM D 3432. Alternatively, it can also be measured by liquid chromatography under the following conditions.

[0039] Equipment: Waters Corporation "ACQUITY UPLC H-Class" Data processing: Waters Corporation "Empower-3" Column: Waters Corporation "ACQUITY UPLC HSS T3" (100 mm x 2.1 mmφ, 1.8 μm) 40°C Eluent: Ammonium formate aqueous solution / methanol, 0.3 mL / min Detector: PDA Sample preparation: 1. Dissolve 100 mg of appropriately blocked sample in 10 ml of THF (for LC) 2. Vortex for 30 seconds 3. Dilute appropriately with eluent (mobile phase) 4. Pass through a 0.2 μm filter to prepare the measurement sample. Calculation of area ratio: Calculate using the maximum absorption wavelength for the target substance.

[0040] The content of the diisocyanate monomer can be adjusted, for example, by removing the diisocyanate monomer from a composition containing the diisocyanate monomer using a short-path distillation apparatus or a thin-film distillation apparatus.

[0041] The polyisocyanate composition (X) can be prepared by adding an acid anhydride (B) during the synthesis of a polyurethane polyisocyanate (A1), obtaining a composition containing the polyurethane polyisocyanate (A1) and the acid anhydride (B), and then removing the diisocyanate monomer using a short-path distillation apparatus or a thin-film distillation apparatus; by heating the polyurethane polyisocyanate (A1) from which the diisocyanate monomer has been removed and the acid anhydride (B) to approximately 50°C to 150°C; or by removing the diisocyanate monomer from a composition containing the polyurethane polyisocyanate (A1), the diisocyanate monomer, and the acid anhydride (B) using a short-path distillation apparatus or a thin-film distillation apparatus. In either preparation method, compounds other than the polyurethane polyisocyanate (A1) and the acid anhydride (B) may be present in the system as long as they do not impair the effects of the present invention. Examples of such compounds include an isocyanate derivative (A2).

[0042] Acid anhydride (B) has been used as an additive in solvent-based two-component curing adhesives, but most of these are solid at room temperature. Therefore, simply adding it to a solventless adhesive does not fully demonstrate its effectiveness. In the production process of polyurethane polyisocyanate, which is widely used as an isocyanate component in solventless two-component curing adhesives, adding acid anhydride (B) to a diisocyanate monomer and dissolving the acid anhydride (B) by heating reduces the strength loss after retort treatment, but does not maintain the performance of the bag material when stored for a long period of time after retort treatment. In the present invention, these problems are resolved by using polyurethane polyisocyanate (A1) in combination with acid anhydride (B) and minimizing the content of diisocyanate monomer in polyisocyanate composition (X). This provides an adhesive that exhibits excellent adhesion to metal substrates and metal vapor-deposited layers and excellent resistance to acids and oils, even after storing the bag material after retort treatment for a certain period of time.

[0043] The viscosity of the polyisocyanate composition (X) is adjusted to a range suitable for the non-solvent lamination method. For example, the viscosity at 40°C is adjusted to a range of 100 to 20,000 mPas, more preferably 500 to 10,000 mPas. The viscosity of the polyisocyanate composition (X) can be adjusted, for example, by the structure of the polyurethane polyisocyanate (A) (the polyol used). The viscosity of the polyisocyanate composition (X) can be measured, for example, using a rotational viscometer with a cone and plate of 1° x 50 mm diameter and a shear rate of 100 sec. －１ , can be measured at 40°C ± 1°C.

[0044] (Polyol composition (Y)) (Polyol (C)) The polyol composition (Y) contains a polyol (C). Examples of such polyols include polyester polyols (C1), polyether polyols (C2), vegetable oil polyols (C3), polyurethane polyols (C4), and sugar alcohols (C5), which may be used alone or in combination of two or more.

[0045] Examples of the polyester polyol (C1) include polyester polyols that are reaction products of polyhydric alcohols and polycarboxylic acids, and lactone-based polyester polyols obtained by polycondensation of aliphatic polyols and various lactones such as ε-caprolactone. It is preferable to use polyester polyols that are reaction products of polyhydric alcohols and polycarboxylic acids. The polyhydric alcohols and polycarboxylic acids may be the same as those exemplified as raw materials for the polyurethane monopolyisocyanate (A1), and may be used alone or in combination.

[0046] The polycarboxylic acid used as the raw material for the polyester polyol (C1) preferably contains an aromatic polycarboxylic acid. The amount of the aromatic polycarboxylic acid in the polycarboxylic acid can be appropriately adjusted depending on the purpose, but is, for example, 20 mass% or more. The entire amount of the polycarboxylic acid may be an aromatic polycarboxylic acid.

[0047] The polyester polyol (C1) preferably has a molecular weight of 300 g / mol to 5000 g / mol, more preferably 400 g / mol to 3000 g / mol, and a hydroxyl value of 20 mg KOH / g to 400 mg KOH / g.

[0048] Examples of the polyether polyol (C2) include those obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of a polymerization initiator such as glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol; and trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and triols of polypropylene glycol. Polypropylene polyol is preferably used.

[0049] The molecular weight of the polyether polyol (C2) can be adjusted appropriately, but is preferably 300 g / mol or more and 5000 g / mol or less, for example. The hydroxyl value of the polyether polyol (C2) can be adjusted appropriately, but is preferably 20 mgKOH / g or more and 500 mgKOH / g or less, for example.

[0050] Examples of the vegetable oil polyol (C3) include castor oil, dehydrated castor oil, hardened castor oil which is a hydrogenated castor oil, and an alkylene oxide 5 to 50 mole adduct of castor oil.

[0051] The polyurethane polyol (C4) is a reaction product of a low-molecular-weight or high-molecular-weight polyol and a polyisocyanate compound. The low-molecular-weight or high-molecular-weight polyol may be the same as the polyhydric alcohol (n). The polyisocyanate compound may be the same as the polyisocyanate (l).

[0052] Examples of sugar alcohols (C5) include pentaerythritol, sucrose, xylitol, sorbitol, isomalt, lactitol, maltitol, and mannitol.

[0053] The polyol (C) preferably contains at least one selected from polyester polyol (C1) and polyether polyol (C2), and more preferably contains polyester polyol (C1). When polyol (C) contains polyester polyol (C1), its content can be appropriately adjusted, but, as an example, it is preferably 20% by mass or more, more preferably 30% by mass or more of the polyol (C). The entire amount of polyol (C) may be polyester polyol (C1).

[0054] (Amine Compound (D)) The polyol composition (Y) may contain an amine compound (D) having an amino group. In this specification, the amino group refers to an amine compound having an NH ２ group or NHR group (R is an alkyl group or aryl group which may have a functional group).

[0055] As the amine compound (D), known compounds can be used without any particular limitation, and examples thereof include methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropanamine-2,4,8,10-tetraoxaspirodoundecane, lysine, 2,2,4-trimethylhexamethylenediamine, hydrazine, piperazine, 2-hydroxyethylethylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, 1,3-diaminopropane,

[0056] 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bishexamethylenetriamine, 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornadiamine,

[0057] amine compounds (D1) having a plurality of amino groups, such as bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, menthenediamine, bis(cyanoethyl)diethylenetriamine, 1,4-bis-(8-aminopropyl)-piperazine, piperazine-1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-(2"-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyureaamines which are reaction products of the above-mentioned various polyamines with the above-mentioned various isocyanate components;

[0058] primary or secondary alkanolamines (D2) such as monoethanolamine, monoisopropanolamine, monobutanolamine, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, and diisopropanolamine;

[0059] Examples thereof include primary or secondary amines (D3) such as ethylamine, octylamine, laurylamine, myristylamine, stearylamine, oleylamine, diethylamine, dibutylamine, and distearylamine.

[0060] The amount of the amine compound (D) to be blended is preferably such that the amine value of the polyol composition (Y) is 20 to 100 mgKOH / g, more preferably 25 to 70 mgKOH / g.

[0061] In this specification, the amine value refers to the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1 g of sample, and is not particularly limited and can be calculated using known methods. When the chemical structure of the amine compound (D) and, if necessary, the average molecular weight, etc. are known, the amine value can be calculated from (number of amino groups per molecule / average molecular weight) x 56.1 x 1000. When the chemical structure, average molecular weight, etc. of the amine compound are unknown, the amine value can be measured according to known amine value measurement methods, for example, JIS K7237-1995.

[0062] (Monool Compound (E)) The polyol composition (Y) may contain a monool compound (E) having one alcoholic hydroxyl group. The main chain of the monool compound (E) is not particularly limited, and examples thereof include vinyl resins, acrylic resins, polyesters, epoxy resins, and urethane resins having one hydroxyl group. Aliphatic alcohols, alkyl alkylene glycols, and the like can also be used. The main chain of the monool compound (E) may be linear or branched. The bonding position of the hydroxyl group is not particularly limited, but it is preferably present at the terminal of the molecular chain.

[0063] Specific examples of the monool compound (E) include aliphatic monools such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, lauryl alcohol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, nonadecanol, other alkanols (C20 to C50), oleyl alcohol, and isomers thereof;

[0064] Cyclohexanol, methylcyclohexanol, 4-butylcyclohexanol, 4-pentylcyclohexanol, 4-hexylcyclohexanol, cyclodecanol, cyclododecanol, cyclopentadecanol, 4-isopropylcyclohexanol, 3,5,5-trimethylcyclohexanol, menthol, 2-norbornanol, borneol, 2-adamantanol, dicyclohexylmethanol, decitol, 2-cyclohexylcyclohexanol, 4-cyclohexylcyclohexanol, 4-(4-propylcyclohexyl)cyclohexanol, 4-(4-pentylcyclohex cyclohexanol, α-ambrinol, desoxycorticosterone, 11-dehydrocorticosterone, cholesterol, β-sitosterol, campesterol, stigmasterol, brassicasterol, lanosterol, ergosterol, β-cholestanol, testosterone, estrone, digitoxigenin, dehydroepiandrosterone, coprostanol, pregnenolone, epicholestanol, 7-dehydrocholesterol, estradiol benzoate, tigogenin, hecogenin, methandienone, cortisone acetate, stenolone, and isomers thereof;

[0065] aromatic aliphatic monools such as benzyl alcohol,

[0066] Examples of the polyoxyalkylene monool include polyoxyalkylene monools obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using an alkyl compound containing one active hydrogen as an initiator.

[0067] The viscosity of the polyol composition (Y) is adjusted to a range suitable for the non-solvent lamination method. For example, the viscosity at 40°C is adjusted to a range of 100 to 50,000 mPas, more preferably 100 to 30,000 mPas. The viscosity of the polyol composition (Y) can be adjusted by the skeleton of the polyol (C) or the plasticizer described below. For example, when adjusting the skeleton of the polyester polyol (C1), the viscosity can be reduced by using a polyester polyol obtained by reacting an aliphatic carboxylic acid with a polyol. Alternatively, the viscosity can be increased by using a polyester polyol (C1) obtained by reacting an aromatic carboxylic acid with a polyol.

[0068] (Other Components of the Adhesive) The two-component curing adhesive of the present invention may contain components other than those described above. The other components may be contained in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or may be prepared separately from these and mixed with the polyisocyanate composition (X) and the polyol composition (Y) immediately before application of the adhesive. Each component will be described below.

[0069] (Catalyst) Examples of the catalyst include metal catalysts, amine catalysts, aliphatic cyclic amide compounds, and quaternary ammonium salts.

[0070] Examples of the metal catalyst include metal complex catalysts, inorganic metal catalysts, and organic metal catalysts. Examples of the metal complex catalyst include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate.

[0071] Examples of inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, and the like.

[0072] Examples of the organometallic catalyst include organic zinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate; organic tin compounds such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organic nickel compounds such as nickel octylate and nickel naphthenate; organic cobalt compounds such as cobalt octylate and cobalt naphthenate; organic bismuth compounds such as bismuth octylate, bismuth neodecanoate, and bismuth naphthenate; titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanium, butoxytitanium trichloride, aliphatic diketones, aromatic diketones, and titanium chelate complexes having at least one of alcohols having 2 to 10 carbon atoms as a ligand.

[0073] Examples of the amine catalyst include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl)isopropyl propanolamine, 3-quinuclidinol, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazole, 1 , 2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 1-(2-hydroxypropyl)-2-methylimidazole, and the like.

[0074] Examples of the aliphatic cyclic amide compound include δ-valerolactam, ε-caprolactam, ω-enantholactam, η-capryllactam, β-propiolactam, etc. Among these, ε-caprolactam is more effective in accelerating curing.

[0075] Examples of quaternary ammonium salts include hydroxy salts of alkyl ammonium, aromatic ammonium, etc., alkyl acid salts, halide salts, etc. Examples include, but are not limited to, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltriethylammonium chloride, hexadecyltrimethylammonium bromide, etc.

[0076] (Coupling Agent) Examples of the coupling agent include silane coupling agents, titanate-based coupling agents, and aluminum-based coupling agents.

[0077] Examples of the silane coupling agent include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, bis[3-(trimethoxysilyl)propyl]amine, and bis[3-(triethoxysilyl)propyl]amine; 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.

[0078] Examples of titanate coupling agents include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.

[0079] Examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.

[0080] (Pigment) The pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments such as extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, and pearlescent pigments listed in the Paint Raw Materials Handbook 1970 Edition (compiled by the Japan Paint Manufacturers Association), as well as plastic pigments.

[0081] Examples of extender pigments include precipitated barium sulfate, powdered barium sulfate, precipitated calcium carbonate, calcium bicarbonate, kansui stone, alumina white, silica, hydrous fine powdered silica (white carbon), ultrafine powdered anhydrous silica (aerosil), silica sand, talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and yellow ochre.

[0082] Specific examples of organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, and Lake 4R; soluble azo pigments such as Lake C, Carmine 6B, and Bordeaux 10; various (copper) phthalocyanine pigments such as Phthalocyanine Blue and Phthalocyanine Green; various chlorine dye lakes such as Rhodamine Lake and Methyl Violet Lake; various mordant dye pigments such as Quinoline Lake and Fast Sky Blue; various vat dye pigments such as Anthraquinone pigments, Thioindigo pigments, and Perinone pigments; various quinacridone pigments such as Synchasia Red B; various dioxazine pigments such as Dioxazine Violet; various condensed azo pigments such as Chromophtal; and aniline black.

[0083] Examples of inorganic pigments include various chromates such as yellow lead, zinc chromate, and molybdate orange; various ferrocyanide compounds such as iron blue; various metal oxides such as titanium oxide, zinc white, mapico yellow, iron oxide, red iron oxide, chrome oxide green, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; flake pigments of these metals, mica flake pigments; metallic pigments and pearl pigments such as mica flake pigments coated with metal oxides and micaceous iron oxide pigments; graphite, carbon black, and the like.

[0084] Examples of plastic pigments include "Grandol PP-1000" and "PP-2000S" manufactured by DIC Corporation.

[0085] The pigment to be used may be selected appropriately depending on the purpose. For example, inorganic oxides such as titanium oxide and zinc oxide are preferably used as white pigments because they have excellent durability, weather resistance, and design properties, and carbon black is preferably used as black pigments.

[0086] The blending amount of the pigment is, for example, 1 to 400 parts by mass per 100 parts by mass of the total amount of nonvolatile components of the polyisocyanate composition (X) and the polyol composition (Y), and is more preferably 10 to 300 parts by mass in order to improve adhesion and blocking resistance.

[0087] (Plasticizer) Examples of the plasticizer include phthalic acid-based plasticizers, fatty acid-based plasticizers, aromatic polycarboxylic acid-based plasticizers, phosphoric acid-based plasticizers, polyol-based plasticizers, epoxy-based plasticizers, polyester-based plasticizers, and carbonate-based plasticizers.

[0088] Examples of the phthalic acid plasticizer include phthalic acid ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate, octyldecyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and diisooctyl isophthalate; and tetrahydrophthalic acid ester plasticizers such as di-(2-ethylhexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

[0089] Examples of the fatty acid plasticizer include adipic acid plasticizers such as di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diglycol adipate; azelaic acid plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, and diisooctyl azelate; and di-n-butyl sebacate and di-(2 Sebacic acid plasticizers such as di-n-butyl maleate, di-(2-ethylhexyl) sebacate, and diisononyl sebacate; maleic acid plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate, and di-(2-ethylhexyl) maleate; fumaric acid plasticizers such as di-n-butyl fumarate and di-(2-ethylhexyl) fumarate; monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, Examples of suitable plasticizers include itaconic acid-based plasticizers such as itaconate and di-(2-ethylhexyl)itaconate; stearic acid-based plasticizers such as n-butyl stearate, glycerin monostearate, and diethylene glycol distearate; oleic acid-based plasticizers such as butyl oleate, glyceryl monooleate, and diethylene glycol monooleate; citric acid-based plasticizers such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, and acetyl tri-(2-ethylhexyl) citrate; ricinoleic acid-based plasticizers such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, glyceryl monoricinoleate, and diethylene glycol monoricinoleate; and other fatty acid-based plasticizers such as diethylene glycol monolaurate, diethylene glycol dipelargonate, and pentaerythritol fatty acid esters.

[0090] Examples of aromatic polycarboxylic acid plasticizers include trimellitic acid plasticizers such as tri-n-hexyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, and triisodecyl trimellitate; and pyromellitic acid plasticizers such as tetra-(2-ethylhexyl) pyromellitate and tetra-n-octyl pyromellitate.

[0091] Examples of phosphoric acid plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, cresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate, and tris(isopropylphenyl) phosphate.

[0092] Examples of polyol-based plasticizers include glycol-based plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexoate), and dibutylmethylene bisthioglycolate; and glycerin-based plasticizers such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.

[0093] Examples of epoxy plasticizers include epoxidized soybean oil, epoxy butyl stearate, di-2-ethylhexyl epoxy hexahydrophthalate, diisodecyl epoxy hexahydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.

[0094] Examples of polyester plasticizers include adipic acid polyesters, sebacic acid polyesters, and phthalic acid polyesters.

[0095] Examples of carbonate plasticizers include propylene carbonate and ethylene carbonate.

[0096] Other examples of the plasticizer include partially hydrogenated terphenyls, adhesive plasticizers, and polymerizable plasticizers such as diallyl phthalate, acrylic monomers and oligomers, etc. These plasticizers can be used alone or in combination of two or more.

[0097] (Phosphate Compound) Examples of the phosphoric acid compound include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate.

[0098] (Form of adhesive) The two-component curing adhesive of the present invention is used in a solventless form. In this specification, a "solventless" adhesive refers to a form of adhesive in which the polyisocyanate composition (X) and the polyol composition (Y) are substantially free of 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, and highly soluble organic solvents such as dimethyl sulfoxide and dimethyl sulfamide, particularly ethyl acetate or methyl ethyl ketone, and which is used in a method in which the adhesive is applied to a substrate and then bonded to another substrate without a step of heating in an oven or the like to volatilize the solvent, i.e., a so-called non-solvent lamination method. If the organic solvent used as a reaction medium during the production of the components of the polyisocyanate composition (X) or the polyol composition (Y) or the raw materials thereof cannot be completely removed, and trace amounts of organic solvent remain in the polyisocyanate composition (X) or the polyol composition (Y), the composition is considered to be substantially free of organic solvent. Furthermore, if the polyol composition (Y) contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with the polyisocyanate composition (X) to become part of the coating film, and therefore does not need to be volatilized after application. Therefore, such a form is also treated as a solventless adhesive, and the low-molecular-weight alcohol is not considered an organic solvent.

[0099] The two-component curing adhesive of the present invention is preferably used by blending the polyisocyanate composition (X) with the polyol composition (Y) so that the ratio [NCO] / [OH], where [NCO] is the number of moles of isocyanate groups contained in the polyisocyanate composition (X) and [OH] is the number of moles of hydroxyl groups contained in the polyol composition (Y), is 1.0 to 5.0. This allows for appropriate curing properties to be obtained without depending on the environmental humidity during application.

[0100] <Other Uses> The polyisocyanate composition (X) described above is suitable as a solventless, two-component curing adhesive for bonding a substrate having a metal foil such as aluminum foil or a metal vapor-deposited layer of aluminum or the like to a plastic film, but can also be used for other purposes. For example, it can be used as a two-component curing coating agent in combination with a composition containing a compound reactive with an isocyanate group (isocyanate-reactive composition). Such a coating agent exhibits excellent adhesion to metal substrates such as steel plates.

[0101] The compound reactive with an isocyanate group can be any known compound and is not particularly limited. Examples include polyols such as polyester polyol, polyether polyol, polycarbonate polyol, and acrylic polyol; compounds having an epoxy group such as bisphenol A type epoxy resin; compounds having a primary or secondary amino group; polyolefins modified with a compound having an acid group and a polymerizable unsaturated group such as maleic anhydride or (meth)acrylic acid; and compounds having an acid group such as copolymers of a compound having an acid group and a polymerizable unsaturated group and a compound having an unsaturated double bond. These compounds can be used alone or in combination of two or more.

[0102] <Laminate> The laminate of the present invention can be obtained, for example, by a method including a two-liquid mixing step in which a polyisocyanate composition (X) and a polyol composition (Y) are mixed in advance, then coated on a first substrate, and then a second substrate is laminated on the coated surface, and the adhesive layer is cured, or by a method including a two-liquid separate coating step in which a polyisocyanate composition (X) and a polyol composition (Y) are separately coated on a first substrate and a second substrate, and then the coated surfaces are brought into contact with each other and pressure-bonded to laminate the first substrate and the second substrate, and the adhesive layer is cured. There are no particular restrictions on the film used, and a film can be appropriately selected depending on the application.

[0103] Examples of films for food packaging include polyethylene terephthalate (PET) films, polystyrene films, polyamide films, polyacrylonitrile films, polyethylene films (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE: biaxially oriented polyethylene film), polypropylene films (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyolefin films such as gas-barrier heat-sealable films in which an olefin-based heat-sealable resin layer is provided on one or both sides of a resin having gas-barrier properties such as an ethylene-vinyl alcohol copolymer or polyvinyl alcohol, polyvinyl alcohol film, and ethylene-vinyl alcohol copolymer film.

[0104] It is also preferable to use biomass films, biodegradable films, and recycled plastic films formed from materials containing biomass-derived components, biodegradable components, or recycled components. Biomass films, biodegradable films, and recycled plastic films are sold by various companies, and films certified in various countries can also be used, such as film sheets listed in the list of biomass-certified products listed by the Japan Organics Recycling Association, films listed in the list of Eco Mark-certified products listed by the Japan Environment Association, and films bearing the symbol mark designated by the Japan Bioplastics Association.

[0105] (Biomass Film) Specific examples of well-known biomass films include those made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol into ethylene oxide by a conventionally known method to produce ethylene glycol. Alternatively, commercially available biomass ethylene glycol may be used; for example, biomass ethylene glycol commercially available from India Glycoal Limited can be suitably used.

[0106] For example, as an alternative to conventional polyethylene terephthalate films made from petroleum-based raw materials, films containing biomass polyesters and biomass polyethylene terephthalates, which have biomass-derived ethylene glycol as the diol unit and fossil fuel-derived dicarboxylic acids as the dicarboxylic acid units, are known.

[0107] The dicarboxylic acid units of the biomass polyester use dicarboxylic acids derived from fossil fuels. Aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their derivatives can be used without limitation as dicarboxylic acids. Furthermore, the biomass polyester may be a copolymer polyester containing, in addition to the diol and dicarboxylic acid components, a bifunctional oxycarboxylic acid or a third copolymer component, such as at least one polyfunctional compound selected from the group consisting of a trifunctional or higher polyhydric alcohol, a trifunctional or higher polycarboxylic acid and / or its anhydride, and a trifunctional or higher oxycarboxylic acid, to form a crosslinked structure.

[0108] Also, for example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films and biomass polyethylene-polypropylene films containing polyethylene resins made from biomass-derived ethylene glycol are known. The polyethylene resin is not particularly limited except that the biomass-derived ethylene glycol is used as part of the raw material, and examples include ethylene homopolymers and copolymers of ethylene and α-olefins containing ethylene as the main component (ethylene-α-olefin copolymers containing 90% by mass or more of ethylene units), and these can be used alone or in combination of two or more.

[0109] The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and examples thereof include α-olefins having 4 to 8 carbon atoms, such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Known polyethylene resins such as low-density polyethylene resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used. Among these, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferred from the viewpoint of further reducing the risk of damage such as holes and tears even when films are rubbed against each other, and has a density of 0.910 to 0.925 g / cm. ３ More preferred is a linear low density polyethylene resin in which

[0110] Biomass films made from biomass raw materials classified by the biomass plastic content specified in ISO 16620 or ASTM D6866 are also on the market. Radioactive carbon-14C exists in the atmosphere at a rate of 1 in 10 particles, and this rate is the same for atmospheric carbon dioxide, so this rate remains the same even in plants that fix carbon dioxide through photosynthesis. Therefore, 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 plant-derived resin content in the resin, i.e., the biomass plastic content, can be determined.

[0111] Examples of plant-derived low-density polyethylene, which is a biomass plastic having a biomass plastic content of 80% or more, preferably 90% or more as specified by ISO 16620 or ASTM D6866, include products manufactured by Braskem under the trade names "SBC818," "SPB608," "SBF0323HC," "STN7006," "SEB853," and "SPB681," and films using these as raw materials can be suitably used.

[0112] Films and sheets containing starch, a biomass material, or polylactic acid are also known. These can be selected and used appropriately depending on the application.

[0113] The biomass film may be a laminate of multiple biomass films or a laminate of a conventional petroleum-based film and a biomass film. These biomass films may be unstretched or stretched, and their manufacturing method is not limited.

[0114] (Biodegradable Films) Specific examples of well-known biodegradable films include those made from commonly available biodegradable resins. Examples include polycaprolactone, polyvinyl alcohol, polyamide, cellulose ester, lactic acid-based polyester resins, aliphatic polyester resins, and aliphatic aromatic polyester resins. These biodegradable resins may be used alone or in combination. Among these, aliphatic polyester resins or aliphatic aromatic polyester resins are preferred. Examples of aliphatic polyester resins include aliphatic polyesters obtained by polycondensation of an aliphatic diol and an aliphatic dicarboxylic acid. Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. These may be used alone or in mixtures. Of these, 1,4-butanediol is preferred. Examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, suberic acid, and dodecanedioic acid, and acid anhydrides derived from these may also be used. Among these, succinic acid or succinic anhydride, or a mixture of these with adipic acid, is preferred. Specific examples include polybutylene succinate (PBS) obtained from 1,4-butanediol and succinic acid (e.g., BioPBS manufactured by PPT MCC Biochem), and polybutylene succinate adipate (PBSA) obtained by copolymerizing PBS with adipic acid.

[0115] Aliphatic aromatic polyester resins include copolymers containing aliphatic dicarboxylic acid units, aromatic dicarboxylic acid units, and linear aliphatic and / or alicyclic diol units. The diol component that provides the diol units typically has 2 to 10 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Among these, diols with 2 to 4 carbon atoms are preferred, with ethylene glycol and 1,4-butanediol being preferred, and 1,4-butanediol being even more preferred. The dicarboxylic acid component that provides the dicarboxylic acid units typically has 2 to 10 carbon atoms, such as succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. Of these, succinic acid or adipic acid is preferred. Examples of aromatic dicarboxylic acid components that provide aromatic dicarboxylic acid units include terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. Among these, terephthalic acid and isophthalic acid are preferred, and terephthalic acid is more preferred.Specific examples include PBAT, which is a copolymer of 1,4-butanediol, adipic acid, and terephthalic acid (for example, Ecoflex manufactured by BASF Co., Ltd.).

[0116] Other examples include poly(3-hydroxyalkanoates) which are aliphatic polyester copolymers obtained from hydroxyalkanoic acids and polycarboxylic acids (particularly, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) (e.g., Aonilex manufactured by Kaneka Corporation), and polylactic acid (PLA) (e.g., REVODE manufactured by Kaisei Biomaterials Co., Ltd., and Ingeo manufactured by NatureWorks).

[0117] The biodegradable film may be a laminate of multiple biodegradable films or a laminate of a conventional petroleum-based film and a biodegradable film. These biodegradable films may be unstretched or stretched, and there are no limitations on the manufacturing method.

[0118] The film may be one that has been subjected to a stretching treatment. A typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-forming method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then transverse stretching. Specifically, a method that combines longitudinal stretching utilizing the speed difference between rolls and transverse stretching using a tenter is often used.

[0119] The film surface may be subjected to various surface treatments such as flame treatment and corona discharge treatment as necessary so that an adhesive layer without defects such as film breakage or repellency is formed.

[0120] Alternatively, a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina, or a barrier film containing a gas barrier layer of polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, vinylidene chloride, etc. Use of such a film can provide a laminate with barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc.

[0121] The paper can be made from any known paper base material without any particular limitations. Specifically, it is produced using natural fibers for papermaking, such as wood pulp, on a known papermaking machine, 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 pulp obtained by chemically modifying these pulps. Examples of pulp that can be used include chemical pulp produced by sulfate cooking, acidic, neutral, or alkaline sulfite cooking, soda cooking, ground pulp, chemi-ground pulp, and thermomechanical pulp. Various commercially available fine paper, coated paper, lined paper, impregnated paper, cardboard, and paperboard can also be used.

[0122] More specific examples of the laminate configuration include, but are not limited to, (1) substrate 1 / adhesive layer 1 / sealant film (2) substrate 1 / adhesive layer 1 / metal-deposited unstretched film (3) substrate 1 / adhesive layer 1 / metal-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-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.

[0123] Examples of the substrate 1 used in structure (1) include MDOPE film, OPE film, OPP film, PET film, nylon film, paper, and the like. Furthermore, the substrate 1 may be coated to improve gas barrier properties or ink receptivity when a printing layer (described later) is provided. 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. A printing layer may be provided on the surface of the substrate 1 facing the adhesive layer 1 (when a coated substrate film 1 is used, the surface of the coating layer facing the adhesive layer 1) or on the surface opposite 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 a common printing method conventionally used for printing on polymer films and paper.

[0124] Examples of the substrate 1 used in structures (2) and (3) include an MDOPE film, an OPE film, an OPP film, a PET film, and paper. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of metal-vapor-deposited unstretched films include a CPP film, an LLDPE film, and a VM-CPP film or a VM-LLDPE film obtained by vapor-depositing a metal such as aluminum on a gas-barrier heat-sealable film. Examples of metal-vapor-deposited stretched films include a VM-MDOPE film, a VM-OPE film, or a VM-OPP film obtained by vapor-depositing a metal such as aluminum on an MDOPE film, an OPE film, or an OPP film. As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0125] Examples of transparent vapor-deposited stretched films used in structure (4) include films obtained by depositing silica or alumina on MDOPE film, OPE film, OPP film, PET film, nylon film, etc. A film with a coating applied to the inorganic vapor-deposited layer of silica or alumina may also be used for the purpose of protecting the inorganic vapor-deposited layer. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealant films include those similar to those in structure (1). A printed layer may be provided on the surface of the transparent vapor-deposited stretched film facing the adhesive layer 1 (when a film with a coating applied to the inorganic vapor-deposited layer is used, the surface of the coating layer facing the adhesive layer 1). The method of forming the printed layer is the same as in structure (1).

[0126] Examples of the substrate 1 used in structure (5) include PET film and paper. Examples of the substrate 2 include nylon film. At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0127] Examples of the substrate 1 in structure (6) include those similar to those in structures (2) and (3). Examples of metal-vapor-deposited stretched films include VM-MDOPE films, VM-OPE films, VM-OPP films, and VM-PET films, which are MDOPE films, OPE films, OPP films, and PET films that have been subjected to metal vapor deposition of aluminum or the like. 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 similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0128] Examples of the substrate 1 in structure (7) include PET film, paper, etc. Examples of the transparent vapor-deposited stretched film include those similar to those in structure (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 similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0129] Examples of the substrate 1 in structure (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 include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0130] Examples of the substrate 1 in structures (9) and (10) include PET film, paper, etc. Examples of the substrate 2 include nylon film, etc. Examples of the metal layer include aluminum foil, etc. At least one layer of the adhesive layers 1, 2, and 3 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0131] The adhesive of the present invention has excellent adhesion to metal substrates and metal vapor-deposited layers. Therefore, when the laminate contains at least one of a metal vapor-deposited film, a transparent vapor-deposited film, and a metal layer, it is preferable that the adhesive layer in contact with the metal vapor-deposited layer, the transparent vapor-deposited layer, or the metal layer, particularly the sealant film side of the adhesive in contact with these layers, is a cured coating film of the adhesive of the present invention.

[0132] Furthermore, the adhesive of the present invention has excellent retort resistance, particularly when it contains an acidic component, and is therefore also preferably used as an adhesive layer in a laminate used to store such contents, for example, in configuration examples (8) to (10).

[0133] The laminate of the present invention may further include other films or substrates in addition to the above-described configurations (1) to (10). As the other substrates, in addition to the above-described stretched films, unstretched films, and transparent vapor-deposited films, porous substrates such as paper, wood, and leather, which will be described later, can also be used. The adhesive used to bond the other substrates may or may not be the adhesive of the present invention.

[0134] The "other layer" may contain known additives or stabilizers, such as antistatic agents, adhesion-enhancing coating agents, plasticizers, lubricants, antioxidants, etc. Furthermore, the "other layer" may be a film whose surface has been pretreated with corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, or the like in order to improve adhesion when laminated with other materials.

[0135] The laminate of the present invention can be suitably used for a variety of applications, such as packaging materials for food, medicines, and daily necessities; lid materials; paper tableware such as paper straws, paper napkins, paper spoons, paper plates, and paper cups; barrier materials; roofing materials; solar cell 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 simultaneous injection molding decoration methods; and packaging materials for liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, and the like.

[0136] <Packaging Material> The laminate of the present invention can be used as a multilayer packaging material for protecting foods, medicines, etc. When used as a multilayer packaging material, the layer structure can be changed depending on the contents, the environment of use, and the form of use. In addition, the packaging of the present invention may be appropriately provided with an easy-open treatment or a resealable means.

[0137] A specific example of the packaging material of the present invention is a packaging material obtained by forming a bag from a laminate having a sealant film, such as the laminate configuration examples (1), (4), and (10) described above. The laminate is folded or overlapped so that the inner layer surfaces (the surfaces of the sealant film) face each other, and the peripheral edges are heat-sealed to form a bag. Examples of bag-making methods include heat-sealing methods using a side seal, two-sided seal, three-sided seal, four-sided seal, envelope seal, flared seal, flat-bottom seal, square-bottom seal, gusset seal, or other heat seal types. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage pattern. Self-standing packaging materials (standing pouches) are also possible. Examples of heat-sealing methods include known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal.

[0138] The packaging material of the present invention is filled with contents through its opening, and then the opening is heat-sealed to produce a product using the packaging material of the present invention. Examples of contents to be filled include foods such as rice crackers, bean snacks, nuts, biscuits, cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candies, and snacks; staple foods such as bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, rice porridge, packaged rice cakes, and cereal foods; processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potatoes; processed livestock products such as ham, bacon, sausages, processed chicken, and corned beef; and processed fish ham and meat products. Examples of such foods include processed seafood products such as sausages, fish paste products, kamaboko, nori seaweed, tsukudani (simmered foods in soy sauce), bonito flakes, salted fish, smoked salmon, and spicy mentaiko; fruit pulp such as peaches, mandarin oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; cooked foods such as frozen and chilled prepared dishes, including hamburgers, meatballs, fried seafood, gyoza, and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; liquid seasonings, retort curry, and pet food.

[0139] In addition, the present invention can also be used as a packaging material for various non-food products, such as cigarettes, disposable body warmers, medicines such as infusion packs, liquid laundry detergent, liquid kitchen detergent, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotion and emulsion, vacuum insulation materials, batteries, etc.

[0140] The present invention will be described in more detail below with reference to specific synthesis examples and examples, but the present invention is not limited to these examples. In the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0141] <Preparation of Polyisocyanate Composition (X)> (Polyisocyanate Composition (X-1)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, water separator, etc. was charged with 72 parts by mass of ethylene glycol, 158 parts by mass of diethylene glycol, 225 parts by mass of neopentyl glycol, 110 parts by mass of hexane glycol, 219 parts by mass of adipic acid, 46 parts by mass of sebacic acid, and 280 parts by mass of isophthalic acid under nitrogen gas introduction. The temperature was gradually increased to 250°C under a normal pressure nitrogen stream while carrying out a dehydration reaction, and the reaction was carried out at 250°C for 2 hours. After confirming that the contents were transparent and that the top temperature of the rectification column was 80°C or less, the temperature was lowered to 240°C, and the rectification column was switched to a condenser. The line was connected to a vacuum pump, and the reaction was continued under a reduced pressure of 30 to 60 Torr until the predetermined acid value and viscosity were reached, thereby obtaining a polyester polyol (PES-1). The reaction product (PES-1) had an acid value of 0.8 mgKOH / g and a hydroxyl value of 265.0 mgKOH / g.

[0142] A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser was charged with 550 parts of xylylene diisocyanate (XDI) and 42.8 parts by mass of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (DIC Epicron B-4500), and heated to 90 ° C. while stirring under a nitrogen gas stream. The mixture was stirred at 90 ° C. until the liquid became transparent, and then cooled to 60 ° C. After that, 450 parts by mass of polyester polyol (PES-1) was charged while taking care not to generate heat, and then heated to 80 ° C. and reacted at 80 ° C. for 2 hours. Next, using a thin-film distillation apparatus, at a pressure of about 0.02 Torr and a temperature of 160 ° C., the XDI in the urethane prepolymer, which is the reaction product of XDI and polyester polyol, was purified to 0.05% by mass in the solids to obtain polyurethane polyisocyanate (A1-1). The NCO % of the polyurethane polyisocyanate (A1-1) was 7.6%.

[0143] 1,000 parts of hexamethylene diisocyanate (HDI) was added to a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, and the mixture was heated to 60°C while stirring. 0.5 parts of a quaternary ammonium salt was added dropwise thereto, and when the predetermined refractive index was reached, a deactivator was added appropriately to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of HDI was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the HDI in the nurate form was 0.05% by mass of the solids, thereby obtaining an isocyanate derivative (A2-1). The NCO% of the isocyanate derivative (A2-1) was 21.8%.

[0144] A reaction vessel equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 700 parts by mass of polyurethane polyisocyanate (A1-1) and 300 parts by mass of isocyanate derivative (A2-1), and the mixture was heated to 60°C while stirring under a nitrogen gas stream. Stirring was continued at 60°C until the liquid became transparent, and the temperature was lowered when the liquid became transparent, thereby obtaining polyisocyanate composition (X-1). The NCO% of polyisocyanate composition (X-1) was 12.3%, the residual XDI was 0.04%, and the residual HDI was 0.04% by mass. The acid value (calculated value) when the acid anhydride group in polyisocyanate composition (X-1) was ring-opened was 25.5 mgKOH / g.

[0145] (Polyisocyanate Composition (X-2)) A reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 785 parts of tolylene diisocyanate (TDI) and 30 parts of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (Epiclon B-4500, manufactured by DIC), and heated to 90°C with stirring under a nitrogen gas stream. Stirring was continued at 90°C until the liquid became transparent, at which point the temperature was lowered to 60°C. Thereafter, 535 parts of bifunctional polypropylene glycol (Exenol 420, manufactured by AGC) was charged, taking care not to generate heat, and the mixture was then heated to 80°C and reacted at 80°C for 2 hours. Next, using a thin-film distillation apparatus, the reaction product of TDI and polypropylene glycol was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI content in the urethane prepolymer was 0.04 mass% of the solids, thereby obtaining polyisocyanate composition (X-2). The NCO% of polyisocyanate composition (X-2) was 11.2%. The acid value (calculated value) when the acid anhydride groups in polyisocyanate composition (X-1) were ring-opened was 25.5 mgKOH / g.

[0146] (Polyisocyanate Composition (X-3)) A reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 550 parts of xylylene diisocyanate (XDI) and 7.1 parts of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (Epiclon B-4500, manufactured by DIC), and heated to 90°C with stirring under a nitrogen gas stream. Stirring was continued at 90°C until the liquid became transparent, at which point the temperature was lowered to 60°C. Thereafter, 450 parts of polyester polyol (PES-1) was charged, taking care not to generate heat, and the mixture was then heated to 80°C and reacted at 80°C for 2 hours. Next, using a thin-film distillation apparatus, the reaction product of XDI and polyester polyol was purified at a pressure of about 0.02 Torr and a temperature of 160°C until the XDI content in the urethane prepolymer, which was the reaction product, was 0.05 mass% of the solid content, thereby obtaining polyurethane polyisocyanate (A1-2). The NCO% of polyurethane polyisocyanate (A1-2) was 7.6%.

[0147] A reaction vessel equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 700 parts by mass of polyurethane polyisocyanate (A1-2) and 300 parts by mass of isocyanate derivative (A2-1), and the mixture was heated to 60°C while stirring under a nitrogen gas stream. Stirring was continued at 60°C until the liquid became transparent, and the temperature was lowered when the liquid became transparent, thereby obtaining polyisocyanate composition (X-3). The NCO% of polyisocyanate composition (X-3) was 12.3%, the residual XDI was 0.04% by mass, and the residual HDI was 0.04% by mass. The acid value (calculated value) of polyisocyanate composition (X-3) upon ring-opening of the acid anhydride group was 4.2 mgKOH / g.

[0148] (Polyisocyanate composition (X-4)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser was charged with 785 parts of tolylene diisocyanate (TDI) and 5 parts by mass of pyromellitic anhydride, and heated to 90 ° C. while stirring under a nitrogen gas stream. Stirring was continued at 90 ° C. until the liquid became transparent, and the temperature was reduced to 60 ° C. when it became transparent. Thereafter, 535 parts by mass of bifunctional polypropylene glycol (AGC EXCENOL 420) was charged while taking care not to generate heat, and then heated to 80 ° C. and reacted at 80 ° C. for 2 hours. Next, using a thin-film distillation apparatus, at a pressure of about 0.02 Torr and a temperature of 160 ° C., the TDI in the urethane prepolymer, which is the reaction product of TDI and polypropylene glycol, was purified to 0.04 mass% of the solids to obtain a polyurethane polyisocyanate (A1-3), which was used as polyisocyanate composition (X-4). The NCO% of the polyisocyanate composition (X-4) was 11.2%, and the acid value (calculated value) when the acid anhydride groups in the polyisocyanate composition (X-4) were ring-opened was 5.1 mgKOH / g.

[0149] (Polyisocyanate Composition (X-5)) A reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with 550 parts of xylylene diisocyanate (XDI) and 30 parts by mass of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (Epiclon B-4500, manufactured by DIC), and heated to 90°C with stirring under a nitrogen gas stream. Stirring was continued at 90°C until the liquid became transparent, at which point the temperature was lowered to 60°C. Thereafter, 450 parts by mass of polyester polyol (PES-1) was charged, taking care not to generate heat, and the mixture was then heated to 80°C and reacted at 80°C for 2 hours. Next, the reaction mixture was purified using a thin-film distillation apparatus at a pressure of approximately 0.02 Torr and a temperature of 160°C until the XDI content in the urethane prepolymer, which was the reaction product of XDI and polyester polyol, was 1.40 mass% of the solid content, thereby obtaining polyurethane polyisocyanate (A1-4). The NCO% of polyurethane polyisocyanate (A1-4) was 7.6%.

[0150] A reaction vessel equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 700 parts by mass of polyurethane polyisocyanate (A1-4) and 300 parts by mass of isocyanate derivative (A2-1), and the mixture was heated to 60°C while stirring under a nitrogen gas stream. Stirring was continued at 60°C until the liquid became transparent, and the temperature was lowered when the liquid became transparent, thereby obtaining polyisocyanate composition (X-5). The NCO% of polyisocyanate composition (X-5) was 12.3%, the residual XDI was 1.00%, and the residual HDI was 0.04%. The acid value (calculated value) upon ring-opening of the acid anhydride group in polyisocyanate composition (X-5) was 25.5 mgKOH / g.

[0151] (Polyisocyanate Composition (X-6)) A reaction vessel equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube was charged with 800 parts by mass of the isocyanate derivative (A2-1), 200 parts by mass of a nurate form of isophorone diisocyanate (VESTANAT T-1890 / 100, NCO% 17.3, manufactured by EVONIK), and 30 parts by mass of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (Epicron B-4500, manufactured by DIC), and the mixture was heated to 130°C with stirring under a nitrogen gas stream. Stirring was continued at 130°C until the liquid became transparent, and the temperature was lowered when the liquid became transparent, thereby obtaining polyisocyanate composition (X-6). The NCO% of polyisocyanate composition (X-6) was 20.9%, and the residual HDI was 0.04%. The acid value (calculated value) of the polyisocyanate composition (X-6) upon ring-opening of the acid anhydride group was 25.5 mgKOH / g.

[0152] (Polyisocyanate Composition (X-7)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser was charged with 550 parts by mass of xylylene diisocyanate (XDI), heated to 90°C while stirring under a nitrogen gas stream, and stirring was continued at 90°C until the liquid became transparent. Once transparent, the temperature was lowered to 60°C. Thereafter, 450 parts by mass of polyester polyol (PES-1) was charged, taking care not to generate heat, and then heated to 80°C and reacted at 80°C for 2 hours. Next, using a thin-film distillation apparatus, the reaction product of XDI and polyester polyol was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the XDI in the urethane prepolymer was 0.05% by mass in the solids, thereby obtaining polyurethane polyisocyanate (A1-5). The NCO% of polyurethane polyisocyanate (A1-5) was 7.6%.

[0153] A reaction vessel equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube was charged with 700 parts by mass of polyurethane polyisocyanate (A1-5) and 300 parts by mass of isocyanate derivative (A2-1), and the mixture was heated to 60°C while stirring under a nitrogen gas stream. Stirring was continued at 60°C until the liquid became transparent, and the temperature was lowered when the liquid became transparent, thereby obtaining polyisocyanate composition (X-7). The NCO% of polyisocyanate composition (X-7) was 12.3%, the residual XDI was 0.04%, and the residual HDI was 0.04%.

[0154] (Polyisocyanate Composition (X-8)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser was charged with 785 parts of tolylene diisocyanate (TDI), heated to 90°C while stirring under a nitrogen gas stream, and stirring was continued at 90°C until the liquid became transparent. Once transparent, the temperature was lowered to 60°C. 535 parts by mass of bifunctional polypropylene glycol (AGC EXCENOL 420) was then charged, taking care not to generate heat, and then heated to 80°C and reacted at 80°C for 2 hours. Next, using a thin-film distillation apparatus, the reaction product of TDI and polypropylene glycol was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI in the urethane prepolymer was 0.04% by mass of the solids, thereby obtaining polyurethane polyisocyanate (A1-6), which was used as polyisocyanate composition (X-8). The NCO% of polyisocyanate composition (X-8) was 11.2%.

[0155] <Preparation of Polyol Composition (Y)> (Polyol Composition (Y-1)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, distillation tube, water separator, etc. was charged with 400 parts by mass of propylene glycol, 80 parts by mass of trimethylolpropane, 700 parts by mass of adipic acid, and 0.1 parts by mass of titanium tetraisopropoxide under nitrogen gas introduction, and the mixture was gradually heated so that the temperature at the top of the distillation tube did not exceed 100°C, and the internal temperature was maintained at 250°C. When the acid value reached 1 mgKOH / g or less, the esterification reaction was terminated, and polyol composition (Y-1) was obtained. The hydroxyl value of polyol composition (Y-1) was 152 mgKOH / g.

[0156] (Polyol composition (Y-2)) Castor oil (manufactured by Ito Oil Mills, Ltd.) was used as polyol composition (Y-2).

[0157] (Polyol composition (Y-3)) A reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a rectifying tube, a water separator, etc. was charged with 540 parts of 3-methylpentanediol, 460 parts of isophthalic acid, and 0.1 parts of titanium tetraisopropoxide under nitrogen gas introduction, and the mixture was gradually heated so that the temperature at the top of the rectifying tube did not exceed 100°C, and the internal temperature was maintained at 250°C. When the acid value reached 1 mgKOH / g or less, the esterification reaction was terminated, and polyester polyol (C1) was obtained. The hydroxyl value of polyester polyol (C1) was 224 mgKOH / g.

[0158] A reaction vessel equipped with a stirrer was charged with 300 parts by weight of polyester polyol (C1), 400 parts by weight of polypropylene glycol (AGC, Exenol 420), 120 parts by weight of polypropylene polyol (AGC, Exenol 430), and 0.5 parts by weight of dibutyltin dilaurate, and the mixture was heated to 60 ° C. with stirring. Stirring was continued at 60 ° C. until the liquid became transparent, and when it became transparent, polyoxypropylene triamine (Huntsman, Jeffamine T-403) was added and stirring was continued at 60 ° C. until the liquid became transparent to obtain polyol composition (Y-3). The hydroxyl value of polyol composition (Y-3) was 227.2 mg KOH / g, and the amine value was 60.7 mg KOH / g.

[0159] (Polyol composition (Y-4)) A reaction vessel equipped with a stirrer was charged with 950 parts by mass of polyester polyol (C1) and 50 parts by mass of 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclocarboxylic anhydride (Epiclon B-4500, manufactured by DIC), and the mixture was heated to 90°C with stirring. Stirring was continued at 90°C until the liquid became transparent, and once transparent, the temperature was lowered to obtain polyol composition (Y-4). The hydroxyl value of polyol composition (Y-4) was 152 mgKOH / g, and the acid value upon ring-opening of the acid anhydride group was 42.5 mgKOH / g.

[0160] <Production of Evaluation Samples> (Example 1) 1.4 parts of polyisocyanate composition (X-1) and 0.6 parts of polyol composition (Y-1) were mixed with stirring to prepare an adhesive of Example 1. The adhesive of Example 1 was applied to a PET film (E5102, 12 μm, manufactured by Toyobo Co., Ltd.) at a rate of 2.0 g / m ２ The adhesive was then applied to an aluminum foil (9 μm) using a nip roll (50° C.) at a rate of 2.0 g / m. ２ The mixture was pressed onto a CPP film (Toray Advanced Film Co., Ltd., Torayfan ZK-207, 70 μm) using nip rolls (50° C.) and aged at 40° C. for 3 days to obtain a PET / Al / CPP laminate 1.

[0161] Laminate 1 was cut into a size of 100 mm x 200 mm, folded so that the CPP film was on the inside, and heat-sealed at 1 atm, 210°C, and 1 second to prepare a pouch. Test pieces were prepared by filling the pouch with 1 / 1 / 1 sauce (meat sauce: vegetable oil: vinegar = 1:1:1).

[0162] Examples 2 to 4 Evaluation samples of Examples 2 to 4 were obtained in the same manner as in Example 1, except that the adhesives shown in Table 1 were used.

[0163] Example 5 The polyisocyanate composition (X-1) was applied to a PET film, and the polyol composition (Y-3) was applied to an aluminum foil, and the PET and the aluminum foil were pressure-bonded together using a nip roll (50°C). The coating amounts of the polyisocyanate composition (X-1) and the polyol composition (Y-3) were each 1.4 g / m ２ , 0.6 g / m ２ Subsequently, the polyisocyanate composition (X-1) was applied to an aluminum foil, and the polyol composition (Y-3) was applied to a CPP film, and the resulting mixture was aged at 40°C for 3 days to obtain a PET / Al / CPP laminate 1. The coating amounts of the polyisocyanate composition (X-1) and the polyol composition (Y-3) were each 1.4 g / m ２ , 0.6 g / m ２ It was.

[0164] A test piece filled with a content was prepared in the same manner as in Example 1, except that the laminate 1 prepared in Example 5 was used.

[0165] (Comparative Examples 1 to 4) Evaluation samples of Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that the adhesive used was one shown in Table 2. (Comparative Examples 5 and 6) Evaluation samples of Comparative Examples 5 and 6 were obtained in the same manner as in Example 5, except that the adhesive used was one shown in Table 2.

[0166] <Evaluation> (Normal Adhesion Strength) Using a tensile tester in an atmosphere of 25°C, the adhesive strength (N / 15 mm) between the aluminum foil and the CPP film of Laminate 1 was measured by a T-type peeling method with a peeling speed set to 300 mm / min. The results were evaluated on the following five-point scale and are summarized in Tables 1 and 2. 5: Adhesion strength is 4 N / 15 mm or more 4: Adhesion strength is 3 N / 15 mm or more and less than 4 N / 15 mm 3: Adhesion strength is 2 N / 15 mm or more and less than 3 N / 15 mm 2: Adhesion strength is less than 2 N / 15 mm 1: Peeling occurred before adhesive strength measurement

[0167] (Retort resistance 1) The test pieces were subjected to retort treatment at 121°C for 30 minutes using a shower-type retort sterilizer (Flavor Ace, manufactured by Hisaka Works, Ltd.). After the retort treatment, the test pieces were opened and the adhesive strength was measured in the same manner as for the normal adhesive strength. The results are summarized in Tables 1 and 2.

[0168] (Retort resistance 2) The test pieces were retorted at 121°C for 30 minutes using a shower-type retort sterilizer (Flavor Ace, manufactured by Hisaka Works, Ltd.). The test pieces after retort treatment were stored at 50°C for 4 weeks, then opened, and the adhesive strength was measured in the same manner as for the normal adhesive strength. The results are summarized in Tables 1 and 2.

[0169]

[0170]

Claims

1. A polyisocyanate composition (X) and a polyol composition (Y), the polyisocyanate composition (X) contains a polyurethane polyisocyanate (A1) which is a reaction product of a polyisocyanate (l) and a polyol (m), and an acid anhydride (B), the polyisocyanate (l) does not contain 4,4'-diphenylmethane diisocyanate, the acid value derived from the acid anhydride (B) in the polyisocyanate composition (X) is 1 mgKOH / g or more and 100 mgKOH / g or less, and the content of a diisocyanate monomer in the polyisocyanate composition (X) is 0.1 mass% or less, The two-component curing solventless adhesive, wherein the polyol composition (Y) contains a polyol (C).

2. 2. The two-component curing solventless adhesive according to claim 1, wherein the polyisocyanate (l) is at least one selected from the group consisting of aromatic diisocyanates, araliphatic diisocyanates, and alicyclic diisocyanates.

3. 2. The two-component curing solventless adhesive according to claim 1, wherein the acid anhydride (B) is a non-aromatic carboxylic acid anhydride.

4. The polyol (C) comprises a polyester polyol (C1), 2. The two-component curing solventless adhesive according to claim 1, wherein a content of the polyester polyol (C1) in the polyol (C) is 20 mass % or more.

5. The two-component curing solventless adhesive according to claim 4, wherein the polyester polyol (C1) is a reaction product of a polyhydric alcohol and a polycarboxylic acid, and the polycarboxylic acid includes an aromatic polycarboxylic acid.

6. The two-component curing solventless adhesive according to claim 4, wherein the polyester polyol (C1) has a hydroxyl value of 20 mgKOH / g or more and 400 mgKOH / g or less.

7. The two-component curing solventless adhesive according to claim 1 , wherein the polyol (C) comprises a polyether polyol (C2).

8. 8. The two-component curing solventless adhesive according to claim 7, wherein the polyether polyol (C2) has a hydroxyl value of 20 mgKOH / g or more and 400 mgKOH / g or less.

9. The two-component curing solventless adhesive according to claim 1, wherein the polyisocyanate (l) is at least one selected from toluene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate.

10. A polyurethane polyisocyanate (A1) which is a reaction product of a polyester polyol (l) and a polyisocyanate (m), and an acid anhydride (B), The polyisocyanate (l) does not contain 4,4'-diphenylmethane diisocyanate; The acid value derived from the acid anhydride (B) is 1 mgKOH / g or more and 100 mgKOH / g or less, The content of diisocyanate monomer is 0.1 mass% or less, A solvent-free polyisocyanate composition.

11. A laminate comprising a first substrate, a second substrate, and an adhesive layer that bonds the first substrate and the second substrate, the adhesive layer being a cured coating film of the two-component curing solventless adhesive according to any one of claims 1 to 9.

12. The laminate of claim 11 , wherein the first substrate is a metal foil.

13. The laminate according to claim 11 , wherein the first substrate has a vapor-deposited metal layer.

14. A packaging material comprising the laminate according to claim 11.