WO2026023368A1 - Two-part curable adhesive, laminate, and packaging material - Google Patents

Abstract

Provided is a two-part curable adhesive which, even when used as a solvent-free adhesive in producing a barrier substrate, is less likely to cause a poor appearance.　The two-part curable adhesive comprises a polyisocyanate composition (X) including polyisocyanate compounds (A) and an isocyanate-reactive composition (Y) including a polyol compound (B), wherein the polyisocyanate compounds (A) comprise a polyurethane polyisocyanate (A1), which is a reaction product of toluene diisocyanate and a polyol, and a hexamethylene diisocyanate derivative (A2) and the polyisocyanate composition (X) has a diisocyanate monomer content of 1.0 mass% or less.

Description

Two-component curing adhesives, laminates, packaging materials

The present invention relates to two-component curing adhesives, laminates, and packaging materials.

Composites made by laminating metal foils such as aluminum foil or metallized film with plastic films such as polyethylene, polypropylene, vinyl chloride, polyester, and nylon are used as packaging materials for food, medical products, cosmetics, and daily necessities. These laminates are made by appropriately combining various plastic films, metallized films, or metal foils according to the required characteristics of each application, and bonding them together with an adhesive. The adhesive generally used is a two-component curing type made from a polyol composition and a polyisocyanate composition (see, for example, Patent Document 1).

JP 2014-101422 A

Solvent-free adhesives, which do not contain solvents, are also being investigated and introduced as two-component curing adhesives. Solvent-free adhesives have many advantages, such as no drying process and no solvent emissions, and no concern about solvent remaining in the laminate after bonding plastic films together, or after bonding a plastic film to metal foil or a metal vapor deposition layer. However, when solvent-free adhesives are used to laminate substrates with high gas barrier properties (hereinafter also referred to as barrier substrates), such as films with metal vapor deposition layers such as aluminum or transparent vapor deposition layers of inorganic oxides such as silica or alumina, they are prone to producing poor appearance. This problem becomes more pronounced as the lamination speed increases.

The present invention was made in consideration of these issues, and aims to provide a two-component curing adhesive that suppresses poor appearance even when used as a solvent-free adhesive to manufacture barrier substrates.

In other words, the present invention relates to a two-component curing adhesive comprising a polyisocyanate composition (X) containing a polyisocyanate compound (A) and an isocyanate-reactive composition (Y) containing a polyol compound (B), wherein the polyisocyanate compound (A) contains a polyurethane polyisocyanate (A1) that is a reaction product of toluene diisocyanate and a polyol, and a hexamethylene diisocyanate derivative (A2), and the content of diisocyanate monomer in the polyisocyanate composition (X) is 1.0 mass% or less.

The present invention provides a two-component curing adhesive that suppresses poor appearance even when used as a solvent-free adhesive to manufacture barrier substrates.

<Two-component curing adhesive>
The adhesive of the present invention is a two-component curing adhesive containing a polyisocyanate composition (X) and a polyol composition (Y).

(Polyisocyanate composition (X))
(Polyisocyanate Compound (A))
The polyisocyanate composition (X) contains, as an essential component, a polyisocyanate compound (A) having a plurality of isocyanate groups. The polyisocyanate compound (A) also contains a polyurethane polyisocyanate (A1) and a hexamethylene diisocyanate derivative (A2).

Polyurethane polyisocyanate (A1) is a reaction product of toluene diisocyanate and polyol. The toluene diisocyanate may be either 2,4'-toluene diisocyanate, 2,6'-toluene diisocyanate, or both.

Polyols used in the synthesis of polyurethane polyisocyanate (A1) 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;

Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and 1,3,5-tris(2-hydroxyethyl)isocyanurate;
bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F;
Dimer diol;

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;

Polyester polyols (1) which are reaction products of polyesters obtained by ring-opening polymerization of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone with polyhydric alcohols such as the above-mentioned glycols, glycerin, trimethylolpropane, and pentaerythritol;
Polyester polyol (2) obtained by reacting a bifunctional polyol such as the glycol, dimer diol, or bisphenol with a polycarboxylic acid:
(3) a polyester polyol obtained by reacting a trifunctional or tetrafunctional aliphatic alcohol with a polycarboxylic acid;
(4) a polyester polyol obtained by reacting a difunctional polyol with the trifunctional or tetrafunctional aliphatic alcohol and a polycarboxylic acid;
Polyester polyols (5), which are polymers of hydroxyl acids such as dimethylolpropionic acid and castor oil fatty acid;

a polyether polyurethane polyol obtained by polymerizing the polyether polyol with an isocyanate compound;
a polyester polyether polyurethane polyol obtained by reacting at least one of polyester polyols (1) to (5), a polyether polyol, and an isocyanate compound;
a polyester polyurethane polyol obtained by polymerizing the polyester polyols (1) to (5) with an isocyanate compound;

Castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil (castor oil), and castor oil-based polyols such as 5-50 mole alkylene oxide adducts of castor oil, and mixtures of these, can be used alone or in combination of two or more.

Polyether polyol polymerization initiators include 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;

Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and triols of polypropylene glycol;

Examples include primary or secondary alkylamines such as ethylamine and diethylamine, amine compounds with multiple amino groups such as methylenediamine and ethylenediamine, and amine compounds with active hydrogen groups such as primary or secondary alkanolamines such as monoethanolamine and diethanolamine.

Examples of polycarboxylic acids used in the synthesis of the polyester polyols (2) to (4) 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;
Methyl esters of aromatic polybasic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate;

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;

Alicyclic polybasic acids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic-1,2-anhydride, himic acid anhydride, and HET acid anhydride are examples of such acids, and these can be used alone or in combination of two or more.

The polyol used in the synthesis of polyurethane polyol (A1) preferably has a molecular weight of 50 g/mol or more and 4000 g/mol or less. This prevents poor appearance even when the adhesive of the present invention is used as a solventless adhesive to bond substrates with high gas barrier properties. The polyol used in the synthesis of polyurethane polyol (A1) preferably has a molecular weight of 50 g/mol or more and 2000 g/mol or less, more preferably 50 g/mol or more and 1000 g/mol or less, even more preferably 50 g/mol or more and 800 g/mol or less, and even more preferably 50 g/mol or more and 500 g/mol or less. Note that the molecular weight in this application is a value calculated from the following formula (1).

The effects of the present application are more readily achieved when the polyol used in synthesizing polyurethane polyisocyanate (A1) contains a polyol with a relatively low molecular weight. It is preferable that the polyol contains 20% by mass or more of polyols with a molecular weight of 50 g/mol or more and 500 g/mol or less, and it is even more preferable that the polyol contains 20% by mass or more of polyols with a molecular weight of 50 g/mol or more and 300 g/mol or less.

The polyol used in the synthesis of the polyurethane polyisocyanate (A1) preferably contains at least one selected from glycols, polyether polyols, and polyester polyols.
The polyol used in the synthesis of the polyurethane polyisocyanate (A1) preferably contains at least one selected from glycols, polyether polyols, and polyester polyols in an amount of 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The total amount of the polyol used in the synthesis of the polyurethane polyisocyanate (A1) may be at least one selected from glycols, polyether polyols, and polyester polyols.

Polyurethane polyisocyanate (A1) is obtained by reacting toluene diisocyanate with a polyol under conditions in which the isocyanate groups of the toluene diisocyanate are in excess relative to the hydroxyl groups of the polyol. The equivalent ratio of isocyanate groups to hydroxyl groups [NCO]/[hydroxyl groups] can be adjusted as appropriate, but is, for example, 2.0 or greater and 20.0 or less.

Examples of the hexamethylene diisocyanate derivative (A2) include the biuret form (A2-1), nurate form (A2-2), adduct form (A2-3), allophanate form (A2-4), carbodiimide-modified form (A2-5), uretdione-modified form (A2-6), iminooxadiazinedione form (A2-7), and polyurethane polyisocyanates other than polyurethane polyisocyanate (A1) (A2-7), and these can be used alone or in combination of two or more. The hexamethylene diisocyanate derivative (A2) preferably includes the nurate form (A2-2) of 1,6-hexamethylene diisocyanate.

The polyol used in the synthesis of polyurethane polyisocyanate (A2-7) can be the same as those exemplified as those usable in the synthesis of polyurethane polyisocyanate (A1). It is preferable to use at least one selected from glycols, polyether polyols, and polyester polyols.

The polyisocyanate composition (X) may contain, as the polyisocyanate compound (A), an isocyanate derivative (A3) other than a polyurethane polyisocyanate (A1) or a hexamethylene diisocyanate derivative (A2). Examples of the isocyanate derivative (A3) include conventionally known aromatic diisocyanates, araliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and biuret derivatives (A3-1), nurate derivatives (A3-2), adduct derivatives (A3-3), allophanate derivatives (A3-4), carbodiimide-modified derivatives (A3-5), uretdione-modified derivatives (A3-6), iminooxadiazinedione derivatives (A3-7), and polyurethane polyisocyanates (A3-7) other than the polyurethane polyisocyanates (A1) and (A2-7). These derivatives may be used alone or in combination of two or more.

Aromatic diisocyanates include, for example, 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), and 2,4-toluene. Examples of diisocyanates include, but are not limited to, 2,6-toluene diisocyanate, 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.

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

Aliphatic diisocyanates include, but are not limited to, 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).

Alicyclic diisocyanates include, but are not limited to, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-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).

The polyol used in the synthesis of polyurethane polyisocyanate (A3-7) can be the same as those exemplified as those usable in the synthesis of polyurethane polyisocyanate (A1). It is preferable to use at least one selected from glycols, polyether polyols, and polyester polyols.

The molecular weight of the polyol used in the synthesis of polyurethane polyisocyanate (A3-7) can be adjusted as appropriate, but is, for example, between 50 g/mol and 4000 g/mol. The molecular weight of the polyol can be calculated using the same method as for the raw material polyol of polyurethane polyol (A1).

Polyurethane polyisocyanate (A3-7) is obtained by reacting an isocyanate with a polyol under conditions such that the isocyanate groups of the isocyanate are in excess relative to the hydroxyl groups of the polyol, and then removing unreacted diisocyanate monomer as needed under the same conditions as for polyurethane polyisocyanate (A1). The equivalent ratio of isocyanate groups to hydroxyl groups [NCO]/[hydroxyl groups] can be adjusted as appropriate, but is, for example, between 2.0 and 20.0.

The content of polyurethane polyisocyanate (A1) in polyisocyanate compound (A) (total of polyurethane polyisocyanate (A1), hexamethylene diisocyanate derivative (A2), isocyanate derivative (A3), and the isocyanate monomer described below) can be adjusted appropriately depending on the desired performance, but is, for example, 50% by mass or more and 95% by mass or less, and more preferably 70% by mass or more and 95% by mass or less.

When the polyisocyanate composition (X) contains an isocyanate derivative (A3), the content of the isocyanate derivative (A3) in the polyisocyanate compound (A) can be adjusted appropriately depending on the desired performance, but is, for example, 30 mass% or less.

The polyisocyanate composition (X) used in the present invention has a diisocyanate monomer content of 1.0 mass% 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 above-mentioned isocyanate derivative (A3). It is also preferable that the diisocyanate monomer content in polyisocyanate composition (X) be reduced to 0.5 mass% or less, and even 0.1 mass% or less.

When manufacturing laminates for food packaging using two-component curing adhesives containing aromatic isocyanate prepolymers, unreacted aromatic isocyanate monomers may remain in the adhesive layer. These isocyanate monomers react with surrounding water to form primary aromatic amines (PAA), which may migrate through the film and leach into the contents (food). There are concerns that PAA may be harmful to the human body, and various regulations have been put in place, including the European Commission's detection limits in its regulations on plastic materials and articles intended for food contact.

PAA reacts with unreacted aromatic isocyanate present in the surrounding area, so even if aromatic isocyanate remains in the adhesive layer, the concentration of PAA gradually decreases. It will eventually fall below the detection limit, but from the perspective of manufacturing efficiency of laminates for food packaging, it is preferable for the initial amount of aromatic isocyanate monomer remaining in the adhesive layer to be low. By removing the diisocyanate monomer beforehand, a two-component curing adhesive with excellent manufacturing efficiency can be produced.

Furthermore, from the perspective of occupational safety and health, there is a movement to restrict the use of isocyanate monomers, and the European Commission has adopted the REACH regulation, which prohibits the marketing of products containing 0.1% or more by mass of isocyanate monomers unless certain requirements are met. Removing unreacted diisocyanate monomers until the amount of diisocyanate monomer in the polyisocyanate composition is 0.1% or less by mass will result in a product that complies with these regulations.

The diisocyanate monomer can be removed by distilling it under reduced pressure using a short-path distillation apparatus or thin-film distillation apparatus. The degree of vacuum and distillation temperature are adjusted appropriately depending on the diisocyanate monomer to be removed, but examples are 0.1 mbar or less and 120°C to 190°C. The diisocyanate monomer removal process may be carried out multiple times.

The diisocyanate monomer content can be measured by gas chromatography using an internal standard, for example, in accordance with ASTM D 3432. Alternatively, it can be measured by liquid chromatography according to the following conditions:

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 the solution 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.

The NCO % of polyisocyanate composition (X) can be adjusted appropriately depending on the purpose, but as an example, it is preferably 7% or more and 21% or less.

When the adhesive of the present invention is used as a solventless adhesive, the viscosity of the polyisocyanate composition (X) is adjusted to a range suitable for the non-solvent lamination method. For example, the viscosity at 60°C is adjusted to be in the range of 100 to 20,000 mPas, more preferably 500 to 10,000 mPas. The viscosity of the polyisocyanate composition (X) can be measured, for example, using a rotational viscometer with a cone and plate of 1°×diameter 50 mm, a shear rate of 100 sec ⁻¹ , and a temperature of 60°C±1°C.

When the adhesive of the present invention is used as a solvent-based adhesive, the viscosity of the polyisocyanate composition (X) can be adjusted by diluting it with a solvent.

(Isocyanate-reactive composition (Y))
(Polyol Compound (B))
The isocyanate-reactive composition (Y) contains a polyol compound (B) having multiple hydroxyl groups. Examples of the polyol compound (B) include polyester polyols (B1), polyether polyols (B2), vegetable oil polyols (B3), polyurethane polyols (B4), sugar alcohols (B5), and acrylic polyols (B6). These compounds may be used alone or in combination of two or more.

Examples of polyester polyols (B1) include polyester polyols that are reaction products of polyhydric alcohols and polycarboxylic acids, and lactone-based polyester polyols obtained by polycondensation reactions 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.

Polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, and 2,2,4-trimethyl-1,3-pentanediol;

Aliphatic polyols with three or more functional groups, such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

bisphenols such as bisphenol A and bisphenol F;
alkylene oxide adducts of bisphenol obtained by adding ethylene oxide, propylene oxide, or the like to bisphenols such as bisphenol A and bisphenol F;

Examples include polyether polyols obtained by ring-opening polymerization of aliphatic diols or polyols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether, and these can be used alone or in combination of two or more.

Examples of polycarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid;
Aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid;
and anhydride or ester-forming derivatives of these aliphatic or dicarboxylic acids;
Examples include polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acids, and these may be used alone or in combination of two or more.

The molecular weight of the polyester polyol (B1) is preferably 250 g/mol or more and 20,000 g/mol or less, and more preferably 500 g/mol or more and 10,000 g/mol or less.
The hydroxyl value of the polyester polyol (B1) is preferably 5 mgKOH/g or more and 500 mgKOH/g or less.

Examples of polyether polyols (B2) 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.

Polymerization initiators include 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;

Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and triols of polypropylene glycol;

Examples include primary or secondary alkylamines such as ethylamine and diethylamine, amine compounds with multiple amino groups such as methylenediamine and ethylenediamine, and amine compounds with active hydrogen groups such as primary or secondary alkanolamines such as monoethanolamine and diethanolamine.

The molecular weight of the polyether polyol (B2) can be adjusted as appropriate, but is preferably, for example, 100 g/mol or more and 8000 g/mol or less.
The hydroxyl value of the polyether polyol (B2) can be adjusted as appropriate, but is preferably, for example, from 10 mgKOH/g to 1200 mgKOH/g.

Examples of vegetable oil polyols (B3) include castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated castor oil), and 5 to 50 mole alkylene oxide adducts of castor oil.

Polyurethane polyol (B4) 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 alcohols exemplified as raw materials for polyester polyol (B1). The polyisocyanate compound may be the same as the polyhydric alcohols exemplified as raw materials for isocyanate derivative (A3).

Examples of sugar alcohols (B5) include pentaerythritol, sucrose, xylitol, sorbitol, isomalt, lactitol, maltitol, mannitol, etc.

The acrylic polyol (B6) is obtained by copolymerizing a (meth)acrylic acid ester having a hydroxyl group as an essential component, and optionally a polymerizable unsaturated monomer. In this specification, (meth)acrylic acid means methacrylic acid or acrylic acid.
Examples of the (meth)acrylic acid ester having a hydroxyl group include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and these can be used alone or in combination of two or more.

Examples of the polymerizable unsaturated monomer include alkyl (meth)acrylates having an alkyl group having 1 to 22 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate;
aralkyl (meth)acrylates such as benzyl (meth)acrylate and 2-phenylethyl (meth)acrylate;
cycloalkyl(meth)acrylates such as cyclohexyl(meth)acrylate and isobornyl(meth)acrylate;
ω-alkoxyalkyl (meth)acrylates such as 2-methoxyethyl (meth)acrylate and 4-methoxybutyl (meth)acrylate;
polyfunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate;

(Meth)acrylic acid, maleic acid, itaconic acid, citraconic acid, mesaconic acid, maleic anhydride, 4-methylcyclohex-4-ene-1,2-dicarboxylic anhydride, bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, 1,2,3,4,5,8,9,10-octahydronaphthalene-2,3-dicarboxylic anhydride, 2-octa-1,3-diketospiro[4.4]non-7-ene, bicyclo[ Polymerizable unsaturated monomers having an acid group, such as 2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, maleopimaric acid, tetrahydrophthalic anhydride, methyl-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, methyl-norbornene-5-ene-2,3-dicarboxylic anhydride, norborn-5-ene-2,3-dicarboxylic anhydride, sulfonated styrene, and vinylbenzenesulfonamide;
vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl pivalate, and vinyl benzoate;
Alkyl esters of crotonic acid such as methyl crotonate and ethyl crotonate;
Examples of the dialkyl esters of unsaturated dibasic acids include, but are not limited to, dimethyl maleate, di-n-butyl maleate, dimethyl fumarate, dimethyl itaconate, etc. These may be used alone or in combination of two or more.

(Isocyanate-reactive compound (C))
The isocyanate-reactive composition (Y) may contain an isocyanate-reactive compound (C) other than the polyol compound (B). The isocyanate-reactive compound (C) refers to a compound having a functional group reactive with an isocyanate group, and examples thereof include an amine compound (C1) and a monool compound (C2). These may be used alone or in combination of two or more.

The amine compound (C1) is a compound having an amino group. In this specification, the amino group refers to an _NH2 group or an NHR group (R is an alkyl group or aryl group which may have a functional group).

Amine compounds (C1) can be any known compound without particular limitations, including 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,

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,

Amine compounds (C1-1) having multiple 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 and the above-mentioned various isocyanate components.

Primary or secondary alkanolamines (C1-2), such as monoethanolamine, monoisopropanolamine, monobutanolamine, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, and diisopropanolamine,

Primary or secondary amines (C1-3) such as ethylamine, octylamine, laurylamine, myristylamine, stearylamine, oleylamine, diethylamine, dibutylamine, and distearylamine are examples.

The amount of amine compound (C1) added can be adjusted appropriately depending on the purpose, but as an example, it is preferably added so that the amine value of the isocyanate-reactive composition (Y) is 20 to 70 mg KOH/g, more preferably 25 to 50 mg KOH/g.

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. If the chemical structure of the amine compound (E7) and, if necessary, the average molecular weight, etc. are known, the amine value can be calculated using (number of amino groups per molecule/average molecular weight) x 56.1 x 1000. If 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, such as JIS K7237-1995.

Monool compounds (C2) include compounds having one alcoholic hydroxyl group. The main chain of the monool compound (C2) is not particularly limited, and examples include vinyl resins, acrylic resins, polyesters, epoxy resins, and urethane resins, all of which have one hydroxyl group. Aliphatic alcohols, alkyl alkylene glycols, and the like can also be used. The main chain of the monool compound (C2) may be linear or branched. There are also no particular limitations on the bonding position of the hydroxyl group, but it is preferable that it be at the end of the molecular chain.

Specific examples of monool compounds (C2) 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 (C20-50), oleyl alcohol, and their isomers.

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 Alicyclic monools such as 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 their isomers;

Aromatic aliphatic monools such as benzyl alcohol,

Examples 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.

When the adhesive of the present invention is provided in a solventless form, the viscosity of the isocyanate-reactive composition (Y) is adjusted to a range suitable for the non-solvent lamination method. For example, the viscosity at 40°C is adjusted to be in the range of 100 to 50,000 mPas, more preferably 100 to 20,000 mPas.

(Other components of 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 isocyanate-reactive composition (Y), or may be prepared separately and then mixed with the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) immediately before application of the adhesive. Each component will be described below.

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

Metal catalysts include metal complex, inorganic metal, and organic metal catalysts. Examples of metal complex catalysts 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.

Inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, etc.

Organometallic catalysts include organic zinc compounds such as zinc octoate, 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 octoate and nickel naphthenate; organic cobalt compounds such as cobalt octoate and cobalt naphthenate; organic bismuth compounds such as bismuth octoate, bismuth neodecanoate, and bismuth naphthenate; and titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanium, butoxytitanium trichloride, aliphatic diketones, aromatic diketones, and titanium chelate complexes having at least one alcohol having 2 to 10 carbon atoms as a ligand.

Amine catalysts 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)iso 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, etc.

Aliphatic cyclic amide compounds include δ-valerolactam, ε-caprolactam, ω-enantholactam, η-capryllactam, and β-propiolactam. Of these, ε-caprolactam is more effective at promoting hardening.

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.

(Coupling Agent)
Examples of the coupling agent include a silane coupling agent, a titanate-based coupling agent, and an aluminum-based coupling agent.

Silane coupling agents include aminosilanes such as gamma-aminopropyltriethoxysilane, gamma-aminopropyltrimethoxysilane, N-beta(aminoethyl)-gamma-aminopropyltrimethoxysilane, N-beta(aminoethyl)-gamma-aminopropyltrimethyldimethoxysilane, N-phenyl-gamma-aminopropyltrimethoxysilane, bis[3-(trimethoxysilyl)propyl]amine, and bis[3-(triethoxysilyl)propyl]amine; epoxy silanes such as beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and gamma-glycidoxypropyltriethoxysilane; vinyl silanes such as vinyltris(beta-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and gamma-methacryloxypropyltrimethoxysilane; hexamethyldisilazane, gamma-mercaptopropyltrimethoxysilane, etc.

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.

Examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.

(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.

Examples of extender pigments include precipitated barium sulfate, powdered gofun, 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.

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.

Inorganic pigments include various chromates such as yellow lead, zinc chromate, and molybdate orange; various ferrocyanide compounds such as Prussian 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, etc.

Examples of plastic pigments include Grandor PP-1000 and PP-2000S manufactured by DIC Corporation.

The pigments used may be selected appropriately depending on the purpose, but for example, inorganic oxides such as titanium oxide and zinc oxide are preferred as white pigments due to their excellent durability, weather resistance, and design properties, while carbon black is preferred as a black pigment.

The amount of pigment to be added is, for example, 1 to 400 parts by mass per 100 parts by mass of the total nonvolatile content of the polyisocyanate composition (X) and the isocyanate-reactive composition (Y), and a range of 10 to 300 parts by mass is more preferable to improve adhesion and blocking resistance.

(acid anhydride)
Examples of the acid anhydride 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.

The above-mentioned compounds may be modified with glycol as the acid anhydride. 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 can also be used.

Alternatively, among the compounds listed above, a homopolymer or copolymer of a compound having a polymerizable unsaturated group, such as maleic anhydride, may be used as the acid anhydride. Examples of compounds that can be copolymerized 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. Styrene and p-tert-butylstyrene, which are vinyl compounds having an aromatic ring, are preferred.

(Phosphate derivatives)
Examples of phosphoric acid derivatives 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, polyoxyethylene alkyl ether phosphate, etc. Phosphoric acid, pyrophosphoric acid, triphosphoric acid, and butyl acid phosphate are preferred.

When a phosphoric acid derivative is contained, its content can be adjusted as appropriate, but as an example, it is 10 ppm or more and 5000 ppm or less of the solids content of the polyisocyanate composition (X). It is more preferably 50 ppm or more, and even more preferably 1000 ppm or less.

Examples of plasticizers include phthalate-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.

Examples of phthalate plasticizers include phthalate 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, butyl benzyl phthalate, dicyclohexyl phthalate, octyldecyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and diisooctyl isophthalate; and tetrahydrophthalate ester plasticizers such as di-(2-ethylhexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

Fatty acid plasticizers include, for example, 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, di-( Sebacic acid plasticizers such as 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 and 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.

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.

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.

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.

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.

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

Carbonate plasticizers include propylene carbonate and ethylene carbonate.

Further examples of plasticizers include partially hydrogenated terphenyls, adhesive plasticizers, and polymerizable plasticizers such as diallyl phthalate, acrylic monomers and oligomers. These plasticizers can be used alone or in combination of two or more.

The amount of plasticizer blended can be adjusted appropriately depending on the desired viscosity, but as an example, it is preferable to keep it at 30 mass% or less of the solids content of polyisocyanate composition (X). Polyisocyanate composition (X) does not have to contain a plasticizer.

(Form of adhesive)
The two-component curing adhesive of the present invention can be suitably used for bonding substrates with high gas barrier properties even in a solvent-free form, but can also be used in a solvent-based form. In this specification, a "solvent-based" adhesive refers to a form used in a so-called dry lamination method, in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating film, and then bonded to another substrate. Either one or both of the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) contains an organic solvent capable of dissolving (diluting) the components of the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) used in the present invention.

Examples of organic solvents include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; dimethyl sulfoxide; and dimethyl sulfamide. The organic solvent used as a reaction medium during the production of the components of the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) may also be used as a diluent during application.

In this specification, a "solventless" adhesive refers to a form of adhesive in which the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) are substantially free of esters such as ethyl acetate, butyl acetate, cellosolve acetate, etc.; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, etc.; ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, highly soluble organic solvents such as dimethyl sulfoxide and dimethyl sulfamide, particularly ethyl acetate or methyl ethyl ketone, and which is used in the so-called non-solvent lamination method, in which the adhesive is applied to a substrate and then bonded to another substrate without going through a process of heating in an oven or the like to volatilize the solvent. If trace amounts of organic solvent remain in polyisocyanate composition (X) or isocyanate-reactive composition (Y) due to incomplete removal of the constituent components of polyisocyanate composition (X) or isocyanate-reactive composition (Y) or the organic solvent used as a reaction medium during the production of their raw materials, the composition is considered to be substantially free of organic solvent. Furthermore, if isocyanate-reactive composition (Y) contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with polyisocyanate composition (X) and becomes part of the coating film, so there is no need to volatilize it after application. Therefore, this type of composition is also treated as a solventless adhesive, and the low-molecular-weight alcohol is not considered an organic solvent.

The two-component curing adhesive of the present invention is preferably formulated so that the ratio [NCO]/[isocyanate-reactive functional group] of the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (X) to the number of moles of functional groups reactive with isocyanate [isocyanate-reactive functional group] contained in the isocyanate-reactive composition (Y) is 0.5 to 5.0, more preferably 1.0 to 3.0. This allows for appropriate curing properties to be obtained regardless of the environmental humidity at the time of application.

<Laminate>
The laminate of the present invention can be obtained, for example, by a method having a two-liquid mixing step in which the adhesive of the present invention (a mixture of polyisocyanate composition (X) and isocyanate-reactive composition (Y)) is applied to a first substrate, followed by laminating a second substrate on the coated surface and curing the adhesive layer, or by a method having a two-liquid separate coating step in which the polyisocyanate composition (X) and the isocyanate-reactive composition (Y) are separately applied to a first substrate and a second substrate, followed by laminating the first substrate and the second substrate by bringing their coated surfaces into contact and pressing them together, and then curing the adhesive layer. There are no particular restrictions on the substrate used, and it can be selected appropriately depending on the application.

For example, for food packaging, examples include polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, BOPE: biaxially oriented polyethylene film), polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyolefin films such as ethylene-vinyl alcohol copolymers and gas-barrier heat-sealable films with an olefin-based heat-sealable resin layer on one or both sides of a resin with gas-barrier properties such as polyvinyl alcohol, polyvinyl alcohol film, and ethylene-vinyl alcohol copolymer films.

It is also preferable to use a biomass film, a biodegradable film, or a recycled plastic film formed from a material containing a biomass-derived component, a biodegradable component, or a recycled component.
Biomass films, biodegradable films, and recycled plastic films are sold by various companies. In addition, it is also possible to use films certified in each country, such as film sheets listed in the list of biomass-certified products published by the Japan Organics Resources Association, films listed in the list of Eco Mark-certified products published by the Japan Environment Association, and films bearing the symbol mark designated by the Japan Bioplastics Association.

The film may be one that has been stretched. Typical stretching methods involve melt-extruding the resin into a sheet using an extrusion film-making method, and then performing simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching, followed by transverse stretching. Specifically, a commonly used method combines longitudinal stretching, which utilizes the speed difference between rolls, with transverse stretching using a tenter.

If necessary, the film surface may be subjected to various surface treatments such as flame treatment or corona discharge treatment to ensure an adhesive layer is formed without defects such as film tearing or repellency.

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 such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride may be used in combination. Using such films can create a laminate with barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc.

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. Natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal pulp, and flax pulp, and pulp obtained by chemically modifying these pulps. Pulp types that can be used include chemical pulp produced by sulfate cooking, acidic, neutral, or alkaline sulfite cooking, and soda cooking, as well as 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.

More specifically, the laminate has the following structure:
(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) Transparent vapor-deposited stretched film / adhesive layer 1 / substrate 1 / adhesive layer 2 / sealant film (7) Substrate 1 / adhesive layer 1 / metal-deposited stretched film / adhesive layer 2 / sealant film (8) Substrate 1 / adhesive layer 1 / transparent vapor-deposited stretched film / adhesive layer 2 / sealant film (9) Substrate 1 / adhesive layer 1 / metal layer / adhesive layer 2 / sealant film (10) Substrate 1 / adhesive layer 1 / substrate 2 / adhesive layer 2 / metal layer / adhesive layer 3 / sealant film (11) Substrate 1 / adhesive layer 1 / metal layer / adhesive layer 2 / substrate 2 / adhesive layer 3 / sealant film, etc., but are not limited to these.

The substrate 1 used in structure (1) may include MDOPE film, BOPE film, OPP film, PET film, nylon film, paper, etc. The substrate 1 may also be coated to improve gas barrier properties or ink receptivity when a printing layer (described later) is applied. 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 adhesive layer 1 side of the substrate 1 (on the adhesive layer 1 side of the coating layer when a coated substrate film 1 is used) or on the side 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 traditionally used for printing on polymer films and paper.

The substrate 1 used in structures (2) and (3) may include MDOPE film, BOPE film, OPP film, PET film, paper, etc. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of metal-vapor-deposited unstretched films include CPP film, LLDPE film, and VM-CPP film and VM-LLDPE film, which are gas-barrier heat-sealable films with aluminum or other metal vapor deposition. Examples of metal-vapor-deposited stretched films include MDOPE film, BOPE film, and VM-MDOPE film, VM-BOPE film, and VM-OPP film, which are OPP films with aluminum or other metal vapor deposition. As with structure (1), a printed layer may be provided on either side of the substrate 1.

The transparent vapor-deposited stretched film used in structure (4) may be a film obtained by vapor-depositing silica or alumina onto an MDOPE film, BOPE film, OPP film, PET film, nylon film, or the like. A film with a coating applied to the vapor-deposited inorganic layer of silica or alumina may also be used for the purpose of protecting the vapor-deposited layer. An anchor coat layer may be provided between the vapor-deposited layer and the substrate on which the vapor-deposited layer is provided for the purposes of improving adhesion of the vapor-deposited layer and improving barrier properties. 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 adhesive layer 1 side of the transparent vapor-deposited stretched film (when a coating is applied to the inorganic vapor-deposited layer, the surface of the coating layer facing the adhesive layer 1) . The method for forming the printed layer is the same as in structure (1).

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

The transparent vapor-deposited stretched film used in structure (6) can be the same as that used in structure (4). Examples of the substrate 1 used in structure (6) include PET film and nylon film. At least one of adhesive layers 1 and 2 is a cured coating of the adhesive of the present invention. Examples of the sealant film can be the same as those used in structure (1). A printed layer may be provided on the surface of the transparent vapor-deposited stretched film facing adhesive layer 1 (when a coating is applied to the inorganic vapor-deposited layer, the surface of the coating layer facing adhesive layer 1). The method of forming the printed layer is the same as that used in structure (1).

Examples of the substrate 1 in structure (7) include those similar to those in structures (2) and (3). Examples of metal-vapor-deposited stretched films include VM-MDOPE film, VM-BOPE film, VM-OPP film, and VM-PET film, which are MDOPE film, BOPE film, OPP film, or PET film that have been subjected to metal vapor deposition of aluminum or the like. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As with structure (1), a printed layer may be provided on either side of substrate 1.

Examples of the substrate 1 in structure (8) 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 with structure (1), a printed layer may be provided on either side of the substrate 1.

In structure (9), examples of the substrate 1 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.

In structures (10) and (11), examples of substrate 1 include PET film, paper, etc. Examples of substrate 2 include nylon film, etc. Examples of metal layers include aluminum foil, etc. At least one of adhesive layers 1, 2, and 3 is a cured coating film of the adhesive of the present invention. Examples of sealant films include those similar to those in structure (1). As with structure (1), a printed layer may be provided on either side of substrate 1.

The adhesive of the present invention can provide a laminate in which defects in appearance are suppressed, even when used to laminate a substrate with high gas barrier properties (hereinafter also referred to as a barrier substrate) in which a metal vapor deposition layer or an inorganic oxide vapor deposition layer is provided on a film. Therefore, it can be suitably used in the manufacture of structures (2) to (4) and (6) to (11), particularly structures (4), (6), and (8) in which defects in appearance are easily visible.

Furthermore, when a laminate produced using an adhesive containing a large amount of aromatic diisocyanate monomer as polyisocyanate composition (X) is used to produce packaging that undergoes retort or boiling treatment, there is a risk that PAA (primary aromatic amine) derived from the aromatic polyisocyanate compound will migrate from the adhesive layer to the contents. The PAA in the adhesive layer decreases over time as it reacts with moisture, and retort or boiling treatment cannot be performed until the PAA content falls below a specified value. The adhesive of the present invention exhibits its physical properties even with a small amount of aromatic diisocyanate monomer in the polyisocyanate composition (X), eliminating the above-mentioned concerns and allowing for rapid retort or boiling treatment. Therefore, the adhesive of the present invention is also preferably used to produce laminates for packaging that require boiling or retort treatment.

More specific configurations of the packaging laminate used in boiling treatment or retort treatment include, for example:
PET film/adhesive layer/CPP film,
PET film/adhesive layer/aluminum foil/adhesive layer/CPP film,
PET film/adhesive layer/Ny film/adhesive layer/CPP film,
PET film/adhesive layer/transparent vapor-deposited Ny film/adhesive layer/CPP film,
PET film/adhesive layer/aluminum foil/adhesive layer/Ny film/adhesive layer/CPP film PET film/adhesive layer/Ny film/adhesive layer/aluminum foil/adhesive layer/CPP film
Transparent vapor-deposited PET film/adhesive layer/CPP film,
Transparent vapor-deposited PET film/adhesive layer/Ny film/adhesive layer/CPP film,
OPP film/adhesive layer/CPP film,
OPP film/adhesive layer/transparent vapor-deposited OPP film/adhesive layer/CPP film,
Transparent vapor-deposited OPP film/adhesive layer/CPP film,
Transparent vapor-deposited OPP film/adhesive layer/OPP film/adhesive layer/CPP film,
Transparent vapor-deposited OPE film/adhesive layer/CPP film,
Transparent vapor-deposited OPE film/adhesive layer/LLDPE film,
Ny film/adhesive layer/CPP film transparent vapor deposition Ny film/adhesive layer/CPP film,
Examples include a gas barrier polyolefin film/adhesive layer/CPP film.

In these configurations, it is preferable to use heat-resistant grade OPP film, transparent vapor-deposited OPP film, CPP film, and LLDPE film (those that are less likely to shrink thermally during boiling or retort processing). The adhesive of the present invention is also used to form an adhesive layer that is located on the inner side of the contents when the bag is made. When the laminate has multiple adhesive layers, the other adhesive layers may or may not be cured coating films of the adhesive of the present invention. When the laminate has multiple adhesive layers and at least one of the films other than the sealant film has a transparent vapor-deposited layer, it is preferable that all of the multiple adhesive layers are cured coating films of the adhesive of the present invention.

Other preferred configuration examples include:
OPE film/adhesive layer/LLDPE film,
MDOPE film/adhesive layer/LLDPE film,
HDPE film/adhesive layer/LLDPE film,
Gas barrier polyolefin film/adhesive layer/LLDPE film,
OPP film/adhesive layer/LLDPE film,
PET film/adhesive layer/LLDPE film,
Ny film/adhesive layer/LLDPE film,
PET film/adhesive layer/Ny film/adhesive layer/LLDPE film, etc.
In the above-mentioned configuration, the LLDPE film may be colored white.

When the adhesive of the present invention is solvent-based, the adhesive of the present invention is applied to the film material that will serve as the substrate using a roll such as a gravure roll, and the organic solvent is evaporated by heating in an oven or the like, and then the other substrate is laminated to obtain the laminate of the present invention. After lamination, it is preferable to perform an aging treatment. The aging temperature is preferably room temperature to 80°C, and the aging time is preferably 12 to 240 hours.

When the adhesive of the present invention is a solventless type, the adhesive of the present invention, which has been preheated to approximately 40°C to 100°C, is applied to the film material that will serve as the substrate using a roll such as a gravure roll, and then the other substrate is immediately laminated to obtain the laminate of the present invention. After lamination, it is preferable to perform an aging treatment. The aging temperature is preferably room temperature to 70°C, and the aging time is preferably 6 to 240 hours.

The amount of adhesive to be applied is adjusted appropriately. In the case of a solvent-based adhesive, for example, the amount of solids is adjusted to 1 g/ ^m2 or more and 10 g/ ^m2 or less, preferably 2 g/ ^m2 or more and 5 g/ ^m2 or less. In the case of a solventless adhesive, for example, the amount of adhesive to be applied is adjusted to 1 g/ ^m2 or more and 5 g/ ^m2 or less, preferably 1 g/ ^m2 or ^more and 3 g/m2 or less.

In addition to the above-described components (1) to (11), the laminate of the present invention may further include other films or substrates. As 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 when bonding the other substrates may or may not be the adhesive of the present invention.

The "other layers" may contain known additives and stabilizers, such as antistatic agents, adhesion-enhancing coating agents, plasticizers, lubricants, and antioxidants. Furthermore, the "other layers" may be pre-treated with corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc., to improve adhesion when laminated with other materials.

The laminate of the present invention can be suitably used for a variety of applications, such as packaging materials for food, medicines, and household goods; lid materials; paper tableware such as paper straws, paper napkins, paper spoons, paper plates, and paper cups; barrier materials; roofing materials; solar panel materials; battery packaging materials; window materials; outdoor flooring materials; lighting protection materials; automotive components; signs; stickers; and other outdoor industrial applications; decorative sheets used in 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.

<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 package of the present invention may be appropriately provided with an easy-open treatment or a resealable means.

One specific example of the packaging material of the present invention is a packaging material made by forming a bag from the above-mentioned laminate. 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. 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. Heat-sealing methods include known methods such as bar seal, rotary roll seal, belt seal, impulse seal, high-frequency seal, and ultrasonic seal.

The packaging material of the present invention is filled with contents through its opening, and the opening is then heat-sealed to produce a product using the packaging material of the present invention. Examples of contents that can be filled include food products such as rice crackers, bean snacks, nuts, biscuits, cookies, wafer snacks, marshmallows, pies, semi-dried cakes, candy, and snack foods; bread, snack noodles, instant noodles, dried noodles, pasta, aseptically packaged cooked rice, porridge, porridge, packaged rice cakes, and cereal foods; pickles, boiled beans, natto, miso, frozen tofu, tofu, nametake mushrooms, konjac, processed wild vegetables, jams, peanut cream, salads, frozen vegetables, and processed potato products; livestock products such as ham, bacon, sausages, processed chicken, and corned beef; and fish ham, These include processed seafood products such as sausages, fish paste products, kamaboko, nori seaweed, tsukudani (simmered food 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; prepared foods such as frozen and chilled prepared dishes, including hamburger steaks, 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.

It can also be used as a packaging material for a variety of non-food items, including cigarettes, disposable hand 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.

<Recycled plastics>
The laminate and packaging material of the present invention can be used as raw materials for recycled plastics. The recycled plastics of the present invention are produced by recycling the laminate and packaging material of the present invention as raw materials. There are no particular limitations on the method for recycling the laminate and packaging material, and known methods can be used. Examples include a method in which the laminate and packaging material are crushed, melt-kneaded, and then pelletized and molded, and a method in which the crushed laminate and packaging material are directly fed into an extrusion molding machine without being melt-kneaded or pelletized, and melt-kneaded in the heating barrel of the molding machine to form a molding raw material.

Laminates and packaging materials can be crushed using a known crusher. There are no particular restrictions on the crusher, and examples include methods using a jaw crusher, impact crusher, cutter mill, stamp mill, ring mill, roller mill, jet mill, or hammer mill. The size of the fragments of the printed matter or laminate is preferably 1 mm to 40 mm in side length, and more preferably 8 mm to 20 mm.

It is preferable that the crushed laminate and packaging material be washed before being subjected to heat melting. Examples of washing methods include batch or continuous washing, and water, detergent, neutralizing agent, and alkaline aqueous solution may be used. It is also preferable that the washed laminate and packaging material be dehydrated and dried. Centrifugal dehydration is a suitable method for dehydration, and hot air drying is a suitable method for drying.

By dehydrating and drying, it is possible to adjust the moisture content of the laminate before it is heated and melted. This makes it possible to avoid foaming during the production of recycled plastic. If bubbles form during pellet production, the pressure inside the cylinder changes, causing the extrusion volume and extrusion pressure to fluctuate, which could result in irregular pellet shapes and dimensions. Furthermore, when using the produced pellets to perform secondary molding to produce molded products, unevenness is likely to occur on the surface, which could deteriorate the surface condition of the molded product.

In one embodiment, dehydration and drying are carried out until the moisture content of the laminate to be used in the production of recycled plastic is 3% by mass or less, preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on the total mass of the laminate.

The crushed laminate and packaging material are heated and melted at 120-280°C, and then kneaded. The temperature at which the laminate and packaging material are melted can be adjusted taking into account the glass transition temperature and melting temperature of the laminate or packaging material, the shape to be pelletized, and the pressure applied during the molding process. The screw rotation speed during kneading is, for example, 50-1000 RPM.

The melt-kneaded laminate and packaging material are cooled and shredded into pellets. Examples of pelletization methods include, but are not limited to, the hot cut method and the strand cut method. To prevent foreign matter from being mixed into the pellets, it is preferable that a screen mesh be provided at the discharge port of the melt-kneaded laminate and packaging material. Examples of screen mesh include plain weave, twill weave, plain dutch weave, and twill dutch weave, as well as punched metal types. Taking into account the pressure and clogging of the discharge port, the screen mesh size is preferably 40 mesh or larger, more preferably 80 mesh or larger, and even more preferably 120 mesh or larger. Examples of cooling methods include air cooling, wind cooling, and water cooling. In the present invention, a water cooling step is preferably included. Cooling to 20°C to 80°C is preferred, and cooling to 30°C to 60°C is more preferred.

When the multiple base materials constituting the laminate are made of the same resin type, the laminate of the present invention can be used as is to produce recycled plastic as described above, but it can also be used to produce recycled plastic after being immersed in a release agent (for example, an alkaline solution such as an aqueous sodium hydroxide solution) for a certain period of time to peel off the individual layers of the laminate.

When the multiple substrates constituting the laminate of the present invention are made of different resin types, it is preferable to immerse the laminate in a release agent for a certain period of time to peel off each layer of the laminate, and then separate the laminate by resin type before using it in the production of recycled plastics. Conventional release agents can be used.

The printed layer may be removed before use in the production of recycled plastics. The printed layer can be removed by known methods. The printed layer itself may be formed using printing ink that is easily peeled from the substrate by immersion in a release agent, or a release layer may be formed between the printed layer and the substrate by applying a coating agent containing a resin that is easily peeled from the substrate by immersion in a release agent, and the printed layer may then be provided on top of the release layer.

The recycled plastic of the present invention may contain known additives. Such additives include at least one antioxidant selected from the group consisting of phenolic and phosphorus-based additives; at least one lubricant selected from the group consisting of fatty acid amides, alkylene fatty acid amides, metal soaps, and esters; a hindered amine weather stabilizer; a wax with an acid value of 5 mg KOH/g or less; and at least one antistatic agent selected from the group consisting of fatty acid sulfonates and fatty acid esters.

The recycled plastic of the present invention may contain virgin plastic as a raw material in addition to the laminate and packaging material of the present invention. The added virgin plastic is of the same resin type as the base material used in the laminate of the present invention. The virgin plastic may be added when pelletizing the laminate and packaging material of the present invention, or when molding the pelletized recycled plastic of the present invention. It may also be added both when pelletizing and when molding the recycled plastic. The amount of virgin plastic used in combination when pelletizing the laminate and packaging material of the present invention is, for example, in a laminate/packaging material:virgin plastic ratio range of 100:0 to 25:75 (mass ratio). The amount of virgin plastic used when molding the pelletized recycled plastic of the present invention is, for example, in a recycled plastic:virgin plastic ratio range of 100:0 to 25:75 (mass ratio).

The recycled plastic of the present invention can be used as a raw material for a variety of plastic products. Examples of plastic products include, but are not limited to, automobile parts such as bumpers and interior materials, components for home appliances, shipping pallets and containers, containers such as bottles, hangers, stationery, pots and cups, disposable cutlery, and play equipment. It can also be recycled as film, or the recycled film can be molded and used, for example, as cushioning material for transporting fruit, but this is not limited to this. Methods for converting the recycled plastic of the present invention into film and producing recycled film include known methods such as T-die molding, inflation molding, solution casting molding, and calendar molding. Methods for molding recycled film include known methods such as vacuum molding and hot press molding.

The present invention will be explained in more detail below with reference to specific synthesis examples and working 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.

<Preparation of Polyisocyanate Composition (X)>
(Synthesis Example 1) Polyurethane polyisocyanate (A1-1)
To a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 774.5 parts of toluene diisocyanate (TDI) was added and heated to 40°C while stirring under a nitrogen gas stream. Subsequently, 225.5 parts of bifunctional polyethylene glycol having a molecular weight of 200 was added while taking care not to generate heat, and then the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of TDI was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI in the urethane prepolymer was 0.05% by mass in the solids, thereby obtaining a polyurethane polyisocyanate (A1-1). The NCO% of the polyurethane polyisocyanate (A1-1) was 14.5%.

(Synthesis Example 2) Polyurethane polyisocyanate (A1-2)
To a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 822.8 parts of toluene diisocyanate (TDI) was added and heated to 40°C while stirring under a nitrogen gas stream. Subsequently, 177.2 parts of bifunctional polyethylene glycol having a molecular weight of 150 was added while taking care not to generate heat, and then the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of TDI was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI in the urethane prepolymer was 0.05% by mass of solids, thereby obtaining a polyurethane polyisocyanate (A1-2). The NCO% of the polyurethane polyisocyanate (A1-2) was 16.2%.

(Synthesis Example 3) Polyurethane polyisocyanate (A1-3)
To a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 635.3 parts of toluene diisocyanate (TDI) was added and heated to 40°C while stirring under a nitrogen gas stream. Subsequently, 364.7 parts of bifunctional polyethylene glycol having a molecular weight of 400 was added while taking care not to generate heat, and then the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of TDI was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI in the urethane prepolymer was 0.05% by mass in the solids, thereby obtaining a polyurethane polyisocyanate (A1-3). The NCO% of the polyurethane polyisocyanate (A1-3) was 11.2%.

(Synthesis Example 4) Polyurethane polyisocyanate (A1-4)
To a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 410.6 parts of toluene diisocyanate (TDI) was added and heated to 40°C while stirring under a nitrogen gas stream. Subsequently, 589.4 parts of bifunctional polyethylene glycol having a molecular weight of 1000 was added while taking care not to generate heat, and then the mixture was heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of TDI was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI in the urethane prepolymer was 0.05% by mass in the solids, thereby obtaining polyurethane polyisocyanate (A1-4). The NCO% of polyurethane polyisocyanate (A1-4) was 6.2%.

(Synthesis Example 5) Polyurethane polyisocyanate (A1-5)
A flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, water separator, etc. was charged with 7 parts of ethylene glycol and 35 parts of diethylene glycol, and heated to 80°C while stirring under a nitrogen gas stream. Further, 36 parts of adipic acid and 22 parts of isophthalic acid were charged into the reaction vessel while stirring, and the reaction vessel was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 250°C, and an esterification reaction was carried out. When the acid value reached 12.0 mgKOH/g or less, the temperature was increased to 240°C, and the pressure inside the reaction vessel was gradually reduced. The reaction was carried out at 40 Torr or less, yielding a polyester polyol having an acid value of 1.0 mgKOH/g and a hydroxyl value of 84 mgKOH/g and having hydroxyl groups at both ends.

342.8 parts of toluene diisocyanate (TDI) was added to a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, and the mixture was heated to 40°C while stirring under a nitrogen gas stream. 657.2 parts of the polyester polyol synthesized above were then added, taking care to avoid heat buildup, and the mixture was then heated to 60°C. The reaction was continued at 60°C until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the mixture was purified at a pressure of approximately 0.02 Torr and a temperature of 160°C until the TDI content of the urethane prepolymer, the reaction product of TDI, was reduced to 0.05% by mass of the solids, yielding polyurethane polyisocyanate (A1-5). The NCO% of polyurethane polyisocyanate (A1-5) was 4.8%.

(Synthesis Example 6) Polyurethane polyisocyanate (A1-6)
To a reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and condenser, 582.2 parts of toluene diisocyanate (TDI) was added and heated to 40 ° C. while stirring under a nitrogen gas stream. Thereafter, 278.5 parts of bifunctional polyethylene glycol having a molecular weight of 400 and 139.3 parts of bifunctional polypropylene glycol having a molecular weight of 1000 were added while taking care not to generate heat, and then the mixture was heated to 60 ° C. The reaction was continued at 60 ° C. until the NCO% no longer changed, and 1.0 part of polyphosphoric acid was added to terminate the reaction. Next, using a thin-film distillation apparatus, the reaction product of TDI was purified at a pressure of about 0.02 Torr and a temperature of 160 ° C. until the TDI in the urethane prepolymer was 0.05 mass% in the solids content, thereby obtaining a polyurethane polyisocyanate (A1-6). The NCO% of the polyurethane polyisocyanate (A1-6) was 9.4%.

(Synthesis Example 7) Polyurethane polyisocyanate (A'1)
A flask equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification tube, water separator, etc. was charged with 7 parts of ethylene glycol and 35 parts of diethylene glycol, and heated to 80°C while stirring under a nitrogen gas stream. Further, 36 parts of adipic acid and 22 parts of isophthalic acid were charged into the reaction vessel while stirring, and the reaction vessel was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 250°C, and an esterification reaction was carried out. When the acid value reached 12.0 mgKOH/g or less, the temperature was increased to 240°C, and the pressure inside the reaction vessel was gradually reduced. The reaction was carried out at 40 Torr or less, yielding a polyester polyol having an acid value of 1.0 mgKOH/g and a hydroxyl value of 84 mgKOH/g and having hydroxyl groups at both ends.

A flask equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 54 parts of a mixture of 2,2-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate, and heated to 60°C while stirring under a nitrogen gas stream. 23 parts of the polyester polyol synthesized above and 23 parts of polypropylene glycol with a number average molecular weight of 1,000 were added dropwise in several batches, and the mixture was further heated and maintained at an internal temperature of 70°C for 4 hours to carry out a urethane reaction, yielding polyurethane polyisocyanate (A'1) with an NCO group content of 14.7%.

(Preparation of Polyisocyanate Composition (X))
Polyisocyanate compositions (X) of the Examples and Comparative Examples were prepared by mixing polyurethane polyisocyanates (A1-1) to (A1-6), (A'1) and hexamethylene diisocyanate derivatives (A2-1) to (A2-3) (referred to as HDI derivatives (A2-1) to (A2-3) in the tables) in the formulations shown in Tables 1 and 2. The following hexamethylene diisocyanate derivatives (A2-1) to (A2-3) were used:

(Hexamethylene diisocyanate derivative (A2-1))
Desmodur N3300 (nurate form of hexamethylene diisocyanate, hexamethylene diisocyanate content: 0.2% by mass), manufactured by Covestro
(Hexamethylene diisocyanate derivative (A2-2))
Desmodur N3200A (bilette of hexamethylene diisocyanate, hexamethylene diisocyanate content: 0.7% by mass), manufactured by Covestro
(Hexamethylene diisocyanate derivative (A2-3))
Takenate D178NL (allophanate of hexamethylene diisocyanate, hexamethylene diisocyanate content: 0.5% by mass), manufactured by Mitsui Chemicals, Inc.

<Preparation of Isocyanate-Reactive Composition (Y)>
(Isocyanate-reactive composition (Y-1))
A polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, and rectification tube was charged with 31.4 parts of diethylene glycol, 9.6 parts of glycerin, 19.9 parts of isophthalic acid, 39.1 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide, and the resulting mixture was subjected to an esterification reaction at an internal temperature of 220 ° C. After the dehydration reaction, a polyester polyol having an acid value of 1.5 mg KOH / g was obtained. 20 parts of polypropylene triol (manufactured by AGC Corporation, Excenol 430, molecular weight 400, trifunctional, hydroxyl value 400 mg KOH / g) was added to 80 parts of this polyester polyol to obtain an isocyanate-reactive composition (Y-1).

(Isocyanate-reactive composition (Y-2))
80 parts of polypropylene glycol (Excenol 420 manufactured by AGC, molecular weight 400, bifunctional, hydroxyl value 280 mgKOH/g) and 20 parts of polypropylene triol (Excenol 430 manufactured by AGC, molecular weight 400, trifunctional, hydroxyl value 400 mgKOH/g) were mixed to obtain an isocyanate-reactive composition (Y-2). The hydroxyl value of the isocyanate-reactive composition (Y-2) was 305 mgKOH/g.

(Isocyanate-reactive composition (Y-3))
A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectification 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 vessel was gradually heated so that the temperature at the top of the rectification tube did not exceed 100°C, and the internal temperature was maintained at 250°C. The esterification reaction was terminated when the acid value reached 1 mgKOH/g or less, yielding a polyester polyol. The hydroxyl value of the polyester polyol was 185 mgKOH/g. 6% by mass of an amine-initiated polypropylene polyol (manufactured by ADEKA Corporation, EDP-450, molecular weight 450, hydroxyl value 505 mgKOH/g) was added to this polyester polyol to yield an isocyanate-reactive composition (Y-3). The hydroxyl value of the isocyanate-reactive composition (Y-3) was 220 mgKOH/g.

(Isocyanate-reactive composition (Y-4))
A polyester reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, rectifying tube, etc. was charged with 203.4 parts of ethylene glycol, 257.5 parts of neopentyl glycol, and 21.0 parts of trimethylolpropane, and heated to 80 ° C. while stirring under a nitrogen gas stream. 384.7 parts of adipic acid and 243.3 parts of isophthalic acid were further added with stirring, and the internal temperature was maintained at 240 ° C. by gradually heating so that the temperature at the top of the rectifying tube did not exceed 100 ° C., and an esterification reaction was carried out. After the reaction, a polyester polyol having hydroxyl groups at both ends with an acid value of 1 mg KOH / g and a hydroxyl value of 196 mg KOH / g was obtained. 80 parts of this polyester polyol and 20 parts of polypropylene triol (AGC Corporation, Excenol 430, molecular weight 400, trifunctional, hydroxyl value 400 mg KOH / g) were mixed to obtain an isocyanate-reactive composition (Y-4). The hydroxyl value of the isocyanate-reactive composition (Y-4) was 240 mgKOH/g.

<Preparation of adhesive>
The polyisocyanate composition (X) and the isocyanate-reactive composition (Y) were mixed in the formulations shown in Tables 3 to 5 to prepare adhesives for the Examples and Comparative Examples.

<Production of Laminate>
(Laminate 1)
The prepared adhesive was applied to a 12 μm thick transparent vapor-deposited polyester film (GL-ARH, manufactured by TOPPAN Corporation) at a coating amount of 2.5 g/m ² (solids content), and this was then laminated to a 15 μm thick nylon film (Emblem ONBC RT, manufactured by Unitika Ltd.). Next, the same adhesive was applied to the nylon film surface of the laminate at a coating amount of 2.5 g/m ² (solids content), and this was then laminated to a 70 μm thick unstretched polypropylene film for retort pouches (Toray Advanced Film Co., Ltd., Torayfan NO ZK207). This was then aged at 40°C for 2 days to obtain Laminate 1.

(Laminate 2)
An anchor coating agent containing a mixture of a silane coupling agent, an acrylic polyol, and an isocyanate curing agent was applied to one side of a 20 μm-thick biaxially oriented polypropylene film to form a 0.3 μm-thick anchor coating layer, and then an aluminum oxide layer having a thickness of 15 nm was formed using an electron beam heating method, thereby obtaining a biaxially oriented polypropylene film having a transparent vapor deposition layer.

The prepared adhesive was applied to a 20 μm thick biaxially oriented polypropylene film (Toyobo Co., Ltd., Pylen EXTOP XP610) at a coating amount of 2.5 g/m ² (solids), and then bonded to the transparent vapor-deposited layer of the above-mentioned transparent vapor-deposited biaxially oriented polypropylene film. Next, the same adhesive was applied to the transparent vapor-deposited biaxially oriented polypropylene film of the laminate at a coating amount of 2.5 g/m ² (solids), and then bonded to a 70 μm thick unstretched polypropylene film for retort pouches (Toray Advanced Film Co., Ltd., Torayfan NO ZK207). Laminate 2 was obtained after aging at 40°C for 2 days.

(Laminate 3)
The prepared adhesive was applied to a 15 μm thick nylon film (Emblem ONBC RT, manufactured by Unitika Ltd.) so that the coating amount was 2.5 g/ ^m2 (solid content), and the adhesive-coated surface of this film was laminated with an unstretched polypropylene film for retort pouches (Toray Film Processing Co., Ltd., Torayfan NO ZK207) using a laminator, followed by aging at 40°C for 2 days to obtain Laminate 3.

<Evaluation>
(retort resistant)
Test pieces were cut from Laminates 1 and 2, folded with the unstretched polypropylene film for retort facing inward, and heat-sealed at three edges (excluding the fold) to a width of 10 mm. 1/1/1 sauce (meat sauce: vegetable oil: vinegar = 1:1:1) was added as the contents. The filled pouches were retorted in a shower-type retort sterilizer at 121°C for 30 minutes. The presence or absence of delamination in the retorted pouches was confirmed. Evaluation was based on the following criteria, and the results are summarized in Tables 3 to 5.
5: No delamination 1: Delamination

(Adhesion strength after retort treatment (Laminate 1))
The contents were removed from the retort-treated pouch, and a 15 mm wide test piece was cut from the pouch. Using a tensile tester, the adhesive strength (N/15 mm) between the nylon film and the unstretched polypropylene film for retort was measured at a peel rate of 300 mm/min using a T-peel method. The evaluation was based on the following criteria, and the results are summarized in Tables 3 to 5.
5: 7N/15mm or more 4: 5N/15mm or more, less than 7N/15mm 3: 4N/15mm or more, less than 5N/15mm 2: 3N/15mm or more, less than 4N/15mm 1: 3N/less than 15mm

(Adhesion strength after retort treatment (Laminate 2))
The contents were removed from the retort-treated pouch, and a 15 mm wide test piece was cut from the pouch. Using a tensile tester, the adhesive strength (N/15 mm) between the transparent vapor-deposited biaxially oriented polypropylene film and the unoriented polypropylene film for retort was measured at a peel rate of 300 mm/min using a T-peel method. Evaluation was performed according to the following criteria, and the results are summarized in Tables 3 to 5.
5: 2.5N/15mm or more 4: 2N/15mm or more, less than 2.5N/15mm 3: 1.5N/15mm or more, less than 2N/15mm 2: 1N/15mm or more, less than 1.5N/15mm 1: Less than 1N/15mm

(PAA elution amount)
Laminates 1, 2, and 3 were each cut into 120 mm x 220 mm pieces, folded so that the unstretched polypropylene film for retort was on the inside, and heat-sealed in three directions at 10 mm width, 1 atm, 180°C, for 1 second to produce pouches with a 2 ^dm2 contact content. Pouches filled with 3% acetic acid vinegar solution were retorted at 121°C for 30 minutes, and then PAA was measured by LC/MS/MS. Evaluation was based on the following criteria, and the results are summarized in Tables 3 to 5.
5: PAA elution amount is less than 2 ppb 3: PAA elution amount is 2 ppb or more but less than 10 ppb 1: PAA elution amount is 10 ppb or more

(Processed appearance)
The prepared adhesive was applied to a 12 μm thick transparent vapor-deposited polyester film (GL-ARH, manufactured by TOPPAN Corporation) at a processing speed of 100 m/min in a coating amount of 2.0 g/ ^m2 (solids content), and then laminated to a 15 μm thick nylon film (Emblem ONBC RT, manufactured by Unitika Ltd.). Next, the same adhesive was applied to the nylon film surface of the laminate at a processing speed of 100 m/min in a coating amount of 2.0 g/ ^m2 (solids content), and then laminated to a 70 μm thick unstretched polypropylene film for retort pouches (Toray Advanced Film Co., Ltd., Torayfan NO ZK207), followed by aging at 40°C for 2 days to obtain Laminate 4. Laminates were obtained in the same manner as Laminate 4, except that the processing speeds were 150 m/min, 180 m/min, and 200 m/min.
The laminate after aging was checked for the presence or absence of bubbles remaining, and the processing speed range in which no bubbles remained was investigated. Evaluation was made according to the following criteria, and the results are summarized in Tables 3 to 5.
5: No bubbles remain even at processing speeds of 200 m/min or more 4: No bubbles remain at 180 m/min 3: No bubbles remain at 150 m/min 2: No bubbles remain at 100 m/min 1: Bubbles remain at 100 m/min

Claims (16)

A polyisocyanate composition (X) containing a polyisocyanate compound (A) and an isocyanate-reactive composition (Y) containing a polyol compound (B),
the polyisocyanate compound (A) contains a polyurethane polyisocyanate (A1) which is a reaction product of toluene diisocyanate and a polyol, and a hexamethylene diisocyanate derivative (A2);
The two-component curing adhesive, wherein the content of the diisocyanate monomer in the polyisocyanate composition (X) is 1.0 mass% or less. The two-component curing adhesive according to claim 1, wherein the polyurethane polyisocyanate (A1) is a reaction product of toluene diisocyanate and a polyol having a molecular weight of 50 g/mol or more and 4000 g/mol or less. The two-component curing adhesive according to claim 1, wherein the polyurethane polyisocyanate (A1) is a reaction product of toluene diisocyanate and a polyol containing 20% by mass or more of a polyol having a molecular weight of 50 g/mol or less and 500 g/mol or less. The two-component curing adhesive according to claim 1, wherein the polyol includes at least one selected from glycol, polyether polyol, and polyester polyol. The two-component curing adhesive according to claim 1, wherein the hexamethylene diisocyanate derivative (A2) includes a nurate form of hexamethylene diisocyanate (A2-2). The two-component curing adhesive according to claim 1, wherein the content of polyurethane polyisocyanate (A1) in polyisocyanate compound (A) is 50% by mass or more and 95% by mass or less. The two-component curing adhesive according to claim 1, wherein the polyol compound (B) includes a polyester polyol (B1). The two-component curing adhesive according to claim 2, wherein the polyol compound (B) includes a polyether polyol (B2). The two-component curing adhesive according to claim 1, which contains at least one selected from a urethane catalyst, a phosphoric acid derivative, a plasticizer, and an acid anhydride. The two-component curing adhesive according to claim 1, which is solvent-free. A laminate comprising a first substrate, a second substrate, and a first adhesive layer disposed between the first substrate and the second substrate, wherein the first adhesive layer is a cured coating film of the two-component curing adhesive described in any one of claims 1 to 10. The laminate described in claim 11, wherein the first substrate has a vapor-deposited layer of an inorganic oxide. The laminate described in claim 11 further includes a third substrate and a second adhesive layer disposed between the second substrate and the third substrate, the second adhesive layer being a cured coating film of the two-component curing adhesive described in any one of claims 1 to 10. A laminate including a first substrate, a second substrate, and a first adhesive layer disposed between the first substrate and the second substrate,
A laminate in which the first substrate and the second substrate are bonded together via the adhesive, and then aged at 40°C for 2 days, and then retorted at 121°C for 30 minutes, the amount of PAA eluted being less than 10 ppb. The laminate described in claim 14, wherein the first substrate has a vapor-deposited layer of an inorganic oxide. A packaging material comprising the laminate described in claim 11.