Adhesive, laminate, and packaging material

Abstract

The present invention provides a two-pack curable adhesive which uses a polyurethane polyisocyanate that suppresses a side reaction when the content of an unreacted isocyanate monomer is removed by distillation during a urethane reaction. A two-part curable adhesive containing a polyisocyanate composition (X) and a polyol composition (Y), the polyisocyanate composition (X) containing a polyurethane polyisocyanate (A1), a diisocyanate monomer (A2) and a polyphosphoric acid (B), the content of the diisocyanate monomer (A2) in the polyisocyanate composition (X) being 0.1 mass% or less, and the content of the polyphosphoric acid (B) being 0.1 mass% or less. The ratio of the polyphosphoric acid (B) to the polyurethane polyisocyanate (A1) is from 100 ppm to 5000 ppm (inclusive).

Description

TECHNICAL FIELD

[0001] The present application relates to an adhesive, a laminate produced using the adhesive, and a packaging material. BACKGROUND

[0002] A laminate for various packaging materials, labels, and the like is given designability, functionality, storability, convenience, transport resistance, and the like by lamination of various and diverse plastic films, metal foils, paper, and the like substrates. A packaging material produced by forming the laminate into a bag shape is used as a packaging material for various fields typified by food, pharmaceuticals, detergents, and the like. In the production of such a laminate, an adhesive of urethane reaction type, either one-component type or two-component type (hereinafter, sometimes referred to as two-component curing type adhesive or reaction type adhesive), is used most often.

[0003] Among two-component curing type adhesives of urethane reaction type, there are adhesives that contain a certain amount of isocyanate monomer as a component like an isocyanate prepolymer, but from the viewpoint of labor safety and hygiene, there are movements to limit the use of isocyanate monomers. The European Commission has enacted the REACH regulation, which prohibits the marketing of products containing 0.1 mass% or more of isocyanate monomers, without meeting certain requirements.

[0004] There are other concerns about isocyanate monomers. When a two-component curing type adhesive containing an aromatic isocyanate prepolymer is used to produce a laminate for food packaging, unreacted aromatic isocyanate monomers can remain in the adhesive layer. The isocyanate monomers react with water present in the surroundings to become primary aromatic amines (PAA), which can migrate in the film and dissolve into the contents (food). PAA is suspected of being harmful to the human body, and the European Commission has set various provisions, such as a provision for setting a detection limit, in the relevant regulations for plastic materials and products in contact with food.

[0005] PAA reacts with unreacted aromatic isocyanate present in the surroundings, so even in the case where aromatic isocyanate remains in the adhesive layer, the concentration of PAA gradually decreases. Although both are below the detection limit, from the viewpoint of the production efficiency of a laminate for food packaging, it is preferable that the initial value of the aromatic isocyanate monomers remaining in the adhesive layer be low.

[0006] Methods for reducing the content of isocyanate monomers have been studied conventionally.

[0007] For example, Patent Document 1 discloses a method for forming an isocyanate-functionalized prepolymer with a low residual isocyanate content, comprising: (a) reacting a polyol selected from polyether polyols, polyester polyols, polyester polyether polyols, acrylic polyols, diols and mixtures thereof with an isocyanate monomer to form a reaction mixture containing a prepolymer having an NCO content of 2.5 to 11.5% by weight and an average NCO functional group in the range of 2.0 to 3.0; and (b) passing the above reaction mixture containing the prepolymer and unreacted isocyanate through a short-path evaporator to remove unreacted isocyanate to an amount of less than 0.15% by weight.

[0008] Patent Document 2 describes a method for manufacturing a one-component laminated adhesive, wherein a diisocyanate monomer and a polyol are reacted in the presence of a catalyst at an NCO / OH ratio of 2.5 or higher to obtain an isocyanate-terminated prepolymer, which is then provided to a thin-film distiller or a molecular distiller to achieve an isocyanate monomer content of 0.1% by mass or less.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2002-265552

[0012] Patent Document 2: European Patent Application Publication No. 3176196 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] When obtaining isocyanate-functionalized prepolymers with low residual isocyanate content using this method, side reactions sometimes occur during the urethane esterification reaction or when removing residual isocyanate monomers from the isocyanate-functionalized prepolymer. Due to these side reactions, the isocyanate-functionalized prepolymer may change color to yellow or brown, or fail to achieve the desired NCO%, thus requiring suppression of these side reactions.

[0015] The present invention was made in view of the following circumstances, and its object is to provide a polyurethane polyisocyanate in which side reactions are suppressed during the urethane esterification reaction by removing the content of unreacted isocyanate monomers through distillation.

[0016] Methods for solving problems

[0017] Specifically, the present invention relates to a two-component curing adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y), wherein the polyisocyanate composition (X) comprises polyurethane polyisocyanate (A1), a diisocyanate monomer (A2), and polyphosphoric acid (B), wherein the content of the diisocyanate monomer (A2) in the polyisocyanate composition (X) is 0.1% by mass or less, and the ratio of polyphosphoric acid (B) to polyurethane polyisocyanate (A1) is 100 ppm or more and 5000 ppm or less.

[0018] Invention Effects

[0019] According to the present invention, a polyurethane polyisocyanate in which the side reactions during the urethane esterification reaction are suppressed by distillation to remove unreacted isocyanate monomers can be obtained. Detailed Implementation

[0020] Two-component curing adhesives

[0021] The adhesive of the present invention is a two-component curing adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y). The adhesive of the present invention will now be described in detail.

[0022] (Polyisocyanate composition (X))

[0023] The polyisocyanate composition (X) used in the adhesive of the present invention comprises polyurethane polyisocyanate (A1), diisocyanate monomer (A2), and polyphosphoric acid (B). Furthermore, the diisocyanate monomer (A2) accounts for less than 0.1% by mass in the polyisocyanate composition (X).

[0024] (Polyurethane polyisocyanate (A1))

[0025] Polyurethane polyisocyanate (A1) is a reaction product of diisocyanate monomers and polyol compounds. The diisocyanate monomers may be one or more known aromatic, aromatic aliphatic, aliphatic, or alicyclic diisocyanates.

[0026] Examples of aromatic diisocyanates include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (also known as MDI), polymethylene polyphenyl polyisocyanate (also known as polymeric MDI or crude MDI), 1,3-phenyl diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenyl diisocyanate (also known as PPDI), and 2,4-toluene diisocyanate. Isocyanates, 2,6-toluene diisocyanate (also known as TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dimethyl biphenyl diisocyanate (also known as TODI), bianisidine diisocyanate, naphthalene diisocyanate (also known as NDI), 4,4'-diphenyl ether diisocyanate, 4,4',4”-triphenylmethane triisocyanate, etc., but not limited to these.

[0027] Aromatic aliphatic diisocyanates refer to aliphatic isocyanates having one or more aromatic rings in their molecules. Examples include meta- or para-phenylenediamine diisocyanate (also known as XDI) and α,α,α',α'-tetramethylphenylenediamine diisocyanate (also known as TMXDI), but are not limited to these.

[0028] Examples of aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate (also known as PDI), 1,2-propylidene diisocyanate, 2,3-butylidene diisocyanate, 1,3-butylidene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate (also known as LDI), but these are not the only examples.

[0029] Examples of alicyclic diisocyanates include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylene dicyclohexyl isocyanate (also known as hydrogenated MDI or HMDI), 1,3-bis(isocyanate methyl)cyclohexane (also known as hydrogenated XDI or HXDI), hydrogenated TMXDI, norbornane diisocyanate (also known as NBDI), etc., but are not limited to these.

[0030] As a polyol compound, conventionally known polyol compounds can be used. Examples include 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, neopentanediol, dimethylbutanediol, butyl ethyl propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dihydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanediol.

[0031] Trifunctional or tetrafunctional aliphatic alcohols such as glycerol, trimethylolpropane, and pentaerythritol;

[0032] Bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, and other bisphenols;

[0033] Dimer diol;

[0034] Polyether polyols are obtained by addition polymerization of ethylene oxide, propylene oxide, butane oxide, phenyl ethylene oxide, epichlorohydrin, tetrahydrofuran, cyclohexene (Japanese: シクロヘキシレン) and other epoxide alkanes in the presence of polymerization initiators such as glycols, trifunctional or tetrafunctional aliphatic alcohols.

[0035] Polyester polyols are products of the reaction of polyesters obtained by the ring-opening polymerization of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone with polyvalent alcohols such as the above-mentioned diols, glycerol, trimethylolpropane, and pentaerythritol (1).

[0036] Polyester polyols obtained by reacting diols, dimer diols, or bisphenols with polycarboxylic acids (2):

[0037] Polyester polyols obtained by reacting trifunctional or tetrafunctional aliphatic alcohols with polycarboxylic acids (3).

[0038] Polyester polyols (4) are obtained by reacting difunctional polyols with trifunctional or tetrafunctional aliphatic alcohols and polycarboxylic acids.

[0039] Polyester polyols are polymers of hydroxy acids such as dimethylolpropionic acid and castor oil fatty acids (5).

[0040] Polyurethane polyol (1) is obtained by increasing the molecular weight of at least one of difunctional, trifunctional or tetrafunctional aliphatic alcohols with an isocyanate compound.

[0041] Polyether polyols are further polymerized by isocyanate compounds to obtain polyether polyurethane polyols (2).

[0042] Polyester polyurethane polyol (3) is obtained by increasing the molecular weight of polyester polyols (1) to (5) with isocyanate compounds.

[0043] Polyester polyether polyurethane polyol (4) is obtained by reacting at least one of polyester polyols (1) to (5) with polyether polyol and isocyanate compound.

[0044] Castor oil, dehydrated castor oil, hydrogenated castor oil as a hydrogenation of castor oil, castor oil-based polyols such as 5-50 molar adducts of castor oil epoxides, and mixtures thereof may be used in one or in combination of two or more.

[0045] Examples of aromatic polycarboxylic acids used in the synthesis of polyester polyols (2) to (4) include phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalic acid, 2,5-naphthalic acid, 2,6-naphthalic acid, 2,3-naphthalic anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyl, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic anhydride, sodium isophthalate-5-sulfonate, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride.

[0046] Methyl esters of aromatic polybasic acids such as dimethyl terephthalate and dimethyl 2,6-naphthalenedicarboxylate;

[0047] Malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid and other aliphatic polyacids;

[0048] Alkyl esters of aliphatic polyacids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl heptaate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate.

[0049] Alicyclic polyacids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, humic anhydride, and chlorobridged anhydride can be used, either one or two or more in combination.

[0050] As the isocyanate compound used in the synthesis of polyurethane polyols (1) to (4), the same isocyanate compound as the diisocyanate monomer exemplified above can be used.

[0051] The polyol compound is preferably a polyether polyol, and more preferably a polyether polyol obtained by addition polymerization of at least one epoxide selected from ethylene oxide, propylene oxide or epoxide butane in the presence of a polymerization initiator such as a diol, a trifunctional or tetrafunctional aliphatic alcohol.

[0052] (Diisocyanate monomer (A2))

[0053] The polyisocyanate composition (X) contains a diisocyanate monomer (A2) in an amount of less than 0.1% by mass of the polyisocyanate composition (X). The diisocyanate monomer (A2) is a residual diisocyanate monomer that was not completely removed during the synthesis of polyurethane polyisocyanate (A1) and the polyisocyanate compound (A3) described later.

[0054] (Other polyisocyanate compounds (A3))

[0055] The polyisocyanate composition (X) used in this invention may comprise a polyisocyanate compound (A3) other than a polyurethane polyisocyanate (A1). Examples of the polyisocyanate compound (A3) include biuret bodies, ureate bodies, ureocarbamate bodies, carbodiimide modified bodies, and ureidone modified bodies of at least one diisocyanate selected from aromatic diisocyanates, aromatic aliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. One polyisocyanate compound (A3) may be used, or two or more may be used in combination.

[0056] Aromatic diisocyanates, aromatic aliphatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates may use the same compounds as those exemplified as raw materials for polyurethane polyisocyanates (A1).

[0057] When the polyisocyanate composition (X) contains a polyisocyanate compound (A3), its usage can be appropriately adjusted, for example, to 5% to 50% by mass of the total amount of polyurethane polyisocyanate (A1).

[0058] (Polyphosphoric acid (B))

[0059] The polyisocyanate composition (X) comprises polyphosphoric acid (B), wherein the ratio of polyphosphoric acid (B) to polyurethane polyisocyanate (A1) is preferably 100 ppm or more and 5000 ppm or less, more preferably 500 ppm or more and 3000 ppm or less. Polyphosphoric acid (B) is a condensate of phosphoric acid and is a compound represented by the following formula (1). In the following formula (1), n ​​is a natural number of 1 or more.

[0060] [Chemical Formula 1]

[0061]

[0062] The polyphosphoric acid (B) used in this invention preferably comprises a compound (B1) in which n is 2 or more and 5 or less in the above formula (1). The content of compound (B1) in polyphosphoric acid (B) is preferably 5% by mass or more and 70% by mass or less.

[0063] (Manufacturing of polyurethane polyisocyanate (A1))

[0064] (Process (1))

[0065] Regarding polyurethane polyisocyanate (A1), a diisocyanate monomer and a polyol compound are reacted under conditions where the isocyanate groups contained in the diisocyanate monomer are in excess relative to the active hydrogen groups contained in the polyol compound, to obtain a composition comprising polyurethane polyisocyanate (A1) and unreacted diisocyanate monomer. The equivalence ratio of isocyanate groups to active hydrogen groups [NCO] / [active hydrogen groups] can be appropriately adjusted, and as an example, it is 2.0 or more and 20.0 or less.

[0066] (Process (2))

[0067] Next, unreacted diisocyanate monomers are removed from the composition obtained in the above steps. The removal of diisocyanate monomers is carried out by distilling the diisocyanate monomers under reduced pressure using a short-path distillation apparatus, a thin-film distillation apparatus, or the like. The reduced pressure and distillation temperature are appropriately adjusted according to the amount of diisocyanate monomer to be removed; for example, 0.1 mbar or less and 120°C to 190°C. The removal process continues until the content of diisocyanate monomers in the total amount of polyurethane polyisocyanate (Al) and diisocyanate monomers becomes less than 0.1% by mass.

[0068] Steps (1) and (2) are carried out in the presence of the aforementioned polyphosphoric acid (B). This suppresses side reactions during urethane esterification and vacuum distillation, resulting in a polyurethane polyisocyanate (A1) with the designed NCO% and minimal coloring. The amount of polyphosphoric acid added is 100 ppm to 5000 ppm or less of the polyurethane polyisocyanate (A1) calculated based on the amount of polyol compound used. It should be noted that the polyurethane polyisocyanate (A1) is calculated as follows: 1 mole of diisocyanate monomer reacts with 1 mole of the active hydrogen group of the polyol compound (for example, in the case of a polyol compound having 2 active hydrogen groups, 1 molecule of the polyol compound reacts with 2 molecules of diisocyanate monomer to form polyurethane polyisocyanate (A1)).

[0069] The content of diisocyanate monomers can be determined according to, for example, ASTM D 3432, by gas chromatography using an internal standard. Alternatively, it can be determined by liquid chromatography under the following conditions.

[0070] Device: "ACQUITY UPLC H-Class" manufactured by Waters Corporation

[0071] Data processing: Waters Corporation, "Empower-3"

[0072] Column: "ACQUITY UPLC HSS T3" manufactured by Waters Corporation (100 mm×2.1 mmφ, 1.8 μm) 40°C

[0073] Eluent: Ammonium formate aqueous solution / methanol, 0.3 mL / min

[0074] Detector: PDA

[0075] Sample preparation: 1. Dissolve 100 mg of a suitable, sealed sample in 10 ml of THF (for LC).

[0076] 2. Vortex for 30 seconds

[0077] 3. Dilute appropriately with elution buffer (mobile phase)

[0078] 4. Pass the liquid through a 0.2 μm filter and prepare the test sample.

[0079] Area ratio calculation: The maximum absorption wavelength is used for the target object.

[0080] When the adhesive of the present invention is used as a solvent-free two-component curing adhesive, the viscosity of the solvent-free polyisocyanate composition (X) is adjusted to a range suitable for solvent-free lamination. For example, the viscosity at 40°C is adjusted to a range of 100–50,000 mPas, more preferably 500–20,000 mPas. Regarding the viscosity of the polyisocyanate composition (X), for example, it can be adjusted by modifying the structure of the polyurethane polyisocyanate (A1) (the polyol used) or by combining it with a polyisocyanate compound (A2). The viscosity of the polyisocyanate composition (X) can be, for example, measured using a rotational viscometer at a cone plate of 1° × diameter 50 mm and a shear rate of 100 sec. -1 The determination was carried out under conditions of 40℃±1℃.

[0081] When the adhesive of the present invention is used as a solvent-based two-component curing adhesive, the viscosity of the polyisocyanate composition (X) can be adjusted to a suitable viscosity for application by diluting it with an organic solvent.

[0082] (Polyol composition (Y))

[0083] The polyol composition (Y) comprises a polyol compound (C) having multiple hydroxyl groups. There are no particular limitations on the polyol compound (C); any polyol compound commonly used in urethane reactive two-component curing adhesives may be used.

[0084] Specific examples of polyol compounds (C) include polyether polyols (C1), polyols with tertiary amino groups (C2), polyester polyols (C3), polyester polyether polyols (C4), polyurethane polyols (C5), polyester polyurethane polyols (C6), polyether polyurethane polyols (C7), vegetable oil polyols (C8), sugar alcohols (C9), polycarbonate polyols (C10), acrylic polyols (C11), hydroxyl-containing olefin resins (C12), and hydroxyl-containing fluoropolymers (C13).

[0085] Examples of polyether polyols (C1) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentanediol, methylpentanediol, dimethylbutanediol, butylethyl propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dihydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanediol, triethylene glycol, etc.; compounds obtained by addition polymerization of ethylene oxide, propylene oxide, butane oxide, phenylethylene oxide, epichlorohydrin, tetrahydrofuran, cyclohexene, etc., in the presence of polymerization initiators such as glycerol, trimethylolpropane, pentaerythritol, triol of polypropylene glycol, etc., which are trifunctional or tetrafunctional aliphatic alcohols.

[0086] Examples of polyols (C2) having a tertiary amino group include compounds obtained by addition polymerization of ethylene oxide, propylene oxide, butane oxide, phenyl ethylene oxide, epichlorohydrin, tetrahydrofuran, cyclohexene, and other alkyl oxides using an amine compound with an active hydrogen group as a polymerization initiator. As the amine compound, conventionally known amine compounds can be used; examples include primary or secondary alkylamines such as ethylamine and diethylamine, amine compounds having multiple amino groups such as methylenediamine and ethylenediamine, and primary or secondary alkyl alcohol amines such as monoethanolamine and diethanolamine.

[0087] Specific examples of such polyols (C2) having a tertiary amine group include, but are not limited to, polypropylene glycol ethylenediamine ether, tris(1,2-polypropylene glycol)amine, N-ethyldiethanolamine, N-methyl-N-hydroxyethyl-N-hydroxyethoxyethylamine, pentahydroxypropyl diethylenetriamine, tetrahydroxypropyl ethylenediamine, etc. One type of polyol (C2) having a tertiary amine group may be used, or two or more may be used in combination. Preferably, the polyol (C2) having a tertiary amine group is a compound having a secondary hydroxyl group.

[0088] Polyester polyols (C3) are reaction products of polyvalent alcohols and polycarboxylic acids. The polyvalent alcohol used in the synthesis of polyester polyols can be a diol or a polyol with more than three functions. Alternatively, polyester polyether polyols can be obtained by using the aforementioned polyether polyols as diols, or polyester polyurethane polyols can be obtained by using the polyurethane polyols described later as diols.

[0089] Examples of aliphatic diols include 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, neopentanediol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, and 2,2,4-trimethyl-1,3-pentanediol.

[0090] Polyoxyethylene glycol, polyoxypropylene glycol and other ether glycols;

[0091] Modified polyether diols are obtained by ring-opening polymerization of aliphatic diols with various compounds containing cyclic ether bonds, such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether.

[0092] Lactone-based polyester polyols are obtained through the polycondensation reaction of aliphatic diols with lactones, ε-caprolactone, and other lactones.

[0093] Bisphenol A, bisphenol F, and other bisphenols;

[0094] Bisphenol alkyl oxide adducts, such as those obtained by adding bisphenols (e.g., bisphenol A, bisphenol F) to ethylene oxide, propylene oxide, etc.

[0095] Examples of polyols with three or more functions include aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerol, hexanetriol, and pentaerythritol.

[0096] Modified polyether polyols are obtained by ring-opening polymerization of aliphatic polyols with various compounds containing cyclic ether bonds, such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether.

[0097] Lactone-based polyester polyols are obtained through the polycondensation reaction of aliphatic polyols with various lactones such as ε-caprolactone.

[0098] Examples of polycarboxylic acids used in the synthesis of polyester polyols (C3) 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 phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalenedicarboxylic acid, biphenyl dicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid; as well as the anhydrides or ester-forming derivatives of these aliphatic or dicarboxylic acids; and polyacids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and their dihydroxycarboxylic acid ester-forming derivatives, and dimer acids.

[0099] Polyurethane polyols (C5) are reaction products of low- or high-molecular-weight polyols and polyisocyanate compounds. As low-molecular-weight polyols, the same substances as the polyvalent alcohols exemplified as raw materials for polyester polyols can be used. Examples of high-molecular-weight polyols include polyether polyols and polyester polyols. As polyisocyanate compounds, the same polyisocyanate compounds exemplified as raw materials for polyurethane polyisocyanates (A1) and polyisocyanate compounds exemplified as polyisocyanate compounds (A3) can be used.

[0100] Examples of vegetable oil polyols (C8) include castor oil, dehydrated castor oil, hydrogenated castor oil as a hydrogenation of castor oil, and 5-50 molar adducts of castor oil epoxides.

[0101] Examples of sugar alcohols (C9) include pentaerythritol, sucrose, xylitol, sorbitol, isomaltitol, lactitol, maltitol, and mannitol.

[0102] The polyisocyanate composition (X) of the present invention has very low diisocyanate monomer content, thus minimizing concerns about PAA. It also achieves the designed NCO% by using the polyphosphoric acid described in this application, and coloring is suppressed. Furthermore, due to its excellent adhesion to metal surfaces, the adhesive of the present invention is suitable for use in laminates used in food packaging, particularly in the manufacture of laminates for packaging materials using aluminum foil or aluminum vapor-deposited films. When the adhesive of the present invention is used for such applications, the polyol compound (C) preferably comprises at least one selected from polyether polyols (C1), polyols having tertiary amino groups (C2), polyester polyols (C3), polyester polyether polyols (C4), polyurethane polyols (C5), polyester polyurethane polyols (C6), polyether polyurethane polyols (C7), vegetable oil polyols (C8), and sugar alcohols (C9).

[0103] The content of these polyol compounds (C) can be appropriately adjusted according to the purpose; for example, it may be 50% by mass or more in the solid component of the polyol composition (Y).

[0104] The hydroxyl value of the polyol compound (C) can be appropriately adjusted; for example, it is 1 mg KOH / g or more and 300 mg KOH / g or less. When the adhesive of the present invention is used as a solvent-free adhesive, the hydroxyl value of the polyol compound (C) is preferably 20 mg KOH / g or more and 300 mg KOH / g or less. When the adhesive of the present invention is used as a solvent-based adhesive, the hydroxyl value of the polyol compound (C) is preferably 1 mg KOH / g or more and 50 mg KOH / g or less. It should be noted that the hydroxyl value of the polyol compound (C) can be calculated based on the average number of functional groups and molecular weight of the polyol compound (C).

[0105] The polyol compound (C) preferably comprises at least one selected from polyether polyol (C1), polyol having a tertiary amine group (C2), and polyester polyol (C3), more preferably comprising at least one selected from polyether polyol (C1) and polyester polyol (C3), and polyol having a tertiary amine group (C2). The amount of polyol having a tertiary amine group (C2) in the polyol compound (C) can be suitably adjusted, for example, to be 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and even more preferably 1% by mass or more and 20% by mass or less.

[0106] (Amine compound (D))

[0107] The polyol composition (Y) may also contain an amine compound (D) having an amino group. It should be noted that, in this specification, the term amino refers to an NH2 group or an NHR group (R is an alkyl or aryl group that may have a functional group).

[0108] As the amine compound (D), known compounds may be used without particular limitation, such as methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropaneamine-2,4,8,10-tetraoxaspiroundecane, lysine, 2,2,4-trimethylhexamethylenediamine, hydrazine, piperazine, 2-hydroxyethylethylenediamine, bis(2-hydroxyethyl)ethylenediamine, bis(2-hydroxyethyl)propylenediamine, 2-hydroxypropylethylenediamine, bis(2-hydroxypropyl)ethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, 1,3-diaminopropane, etc.

[0109] 1,4-Diaminobutane, 1,5-Diaminopentane, 1,6-Diaminohexane, 1,7-Diaminoheptane, 1,8-Diaminooctane, 1,9-Diaminononane, 1,10-Diaminodecane, Diethylenetriamine, Dipropylenetriamine, Triethylenetetramine, Triethylenetetramine, Tetraethylenepentamine, Tetraethylenepentamine, Pentylethylenehexamine, Nonadexethylenedeamine, Trimethylhexamethylenediamine, Tetra(aminomethyl)methane, Tetra(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, Triethylene-bis(trimethylene)hexamine, Bis(3-aminoethyl)amine, Bis(hexamethylene)triamine, 1,4-Cyclohexanediamine, 4,4'-Methylenebicyclohexaneamine, 4,4'-Isopropylidenebicyclohexaneamine, Norbornenediamine,

[0110] Amine compounds having multiple amino groups, such as bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophorone diamine, menthene diamine, bis(cyanoethyl)diethylenetriamine, 1,4-bis(8-aminopropyl)piperazine, piperazine-1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-(2”-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyurea, which are reaction products of the above-mentioned polyamines and the above-mentioned isocyanate components, are included (D1).

[0111] Monoethanolamine, monoisopropanolamine, monobutanolamine, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, diisopropanolamine, and other primary or secondary alkanolamines (D2).

[0112] Primary or secondary amines (D3), such as ethylamine, octylamine, laurylamine, myristicamine, stearylamine, oleylamine, diethylamine, dibutylamine, distearate, etc.

[0113] Regarding the amount of amine compound (D), it is preferred to combine the polyol composition (Y) in such a way that the amine value is 20 to 70 mg KOH / g, more preferably 25 to 50 mg KOH / g.

[0114] It should be noted that the amine value in this specification refers to the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1g of sample, and can be calculated using known methods without particular restriction. When the chemical structure of the amine compound (D) is known, and further, if necessary, the average molecular weight is known, it can be calculated as (number of amino groups per molecule / average molecular weight) × 56.1 × 1000. When the chemical structure, average molecular weight, etc., of the amine compound are unknown, it can be determined according to known methods for amine value determination, such as JIS K7237-1995.

[0115] (Monohydric alcohol compound (E))

[0116] The polyol composition (Y) may also contain a monohydric alcohol compound (E) having one alcoholic hydroxyl group. The main chain of the monohydric alcohol compound (E) is not particularly limited, and examples include vinyl resins, acrylic resins, polyesters, epoxy resins, and urethane resins having one hydroxyl group. Aliphatic alcohols and alkylalkylene glycols may also be used. The main chain of the monohydric alcohol compound (E) can be linear or branched. The bonding position of the hydroxyl group is not particularly limited, but it is preferred to be located at the end of the molecular chain.

[0117] Specific examples of monohydric alcohol compounds (E) include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, lauryl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptyl alcohol, stearyl alcohol, nonadecanol, other alkanols (C20-50), oleyl alcohol, and their isomers, etc., which are aliphatic monohydric alcohols.

[0118] Cyclohexanol, methylcyclohexanol, 4-butylcyclohexanol, 4-pentylcyclohexanol, 4-hexylcyclohexanol, cyclodecyl alcohol, cyclododecanol, cyclopentadecanol, 4-isopropylcyclohexanol, 3,5,5-trimethylcyclohexanol, menthol, 2-norborneol, camphenol, 2-adamantanol, dicyclohexylmethanol, 6-isopropyl-2-decahydronaphthol, 2-cyclohexylcyclohexanol, 4-cyclohexylcyclohexanol, 4-(4-propylcyclohexyl)cyclohexanol, 4-(4-pentylcyclohexyl)cyclohexanol, α-ambroxol, deoxycorticosterone, 11-dehydrocorticosterone Hydrocorticosterone, cholesterol, β-sitosterol, campesterol, stigmasterol, lanosterol, ergosterol, β-cholesterol, testosterone, estrone, digitoxin, dehydroepiandrosterone, coprosterol, pregnenolone, epicholesterol, 7-dehydrocholesterol, estradiol benzoate, sisal saponin, heco saponin, dehydrotestosterone, cortisone acetate, hydroxymethylandrostenone, and their isomers are all alicyclic monohydric alcohols.

[0119] Aromatic aliphatic monohydric alcohols such as benzyl alcohol,

[0120] Polyoxyalkylene monohydric alcohols, etc., are obtained by using alkyl compounds containing one active hydrogen group as initiators and performing ring-opening addition polymerization on ethylene oxide, propylene oxide, butane oxide, tetrahydrofuran, and other alkyl oxides.

[0121] When the two-component curing adhesive of the present invention is used in a solvent-free manner, the viscosity of the polyol composition (Y) is adjusted to a range suitable for solvent-free lamination. For example, the viscosity at 40°C can be adjusted to a range of 100–50,000 mPas, more preferably 100–20,000 mPas. The viscosity of the polyol composition (Y) can be adjusted using the backbone of the polyol compound (C), plasticizers (described later), etc. When adjusting using the backbone of the polyol compound (B), the viscosity can be reduced, for example, by using polypropylene glycol or a polyester polyol obtained from the reaction of an aliphatic carboxylic acid with a polyol. Alternatively, the viscosity can be increased by using a polyester polyol obtained from the reaction of an aromatic carboxylic acid with a polyol.

[0122] (Other components of the adhesive)

[0123] The two-component curing adhesive of the present invention may also contain components other than those described above. Other components may be included in any one or both of the polyisocyanate composition (X) and polyol composition (Y), or may be prepared separately in advance and mixed with the polyisocyanate composition (X) and polyol composition (Y) just before the adhesive is applied. The components are described below.

[0124] (catalyst)

[0125] Examples of catalysts include metal catalysts, amine catalysts, aliphatic cyclic amide compounds, and quaternary ammonium salts.

[0126] Examples of metal-based catalysts include metal complex-based, inorganic metal-based, and organometallic catalysts. Examples of metal complex-based catalysts include acetylacetone salts of metals selected from Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetone, manganese acetylacetone, copper acetylacetone, and zirconium oxide acetylacetone.

[0127] Catalysts selected from inorganic metal systems include Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, and Co.

[0128] Examples of organometallic catalysts include organozinc compounds such as zinc octanoate, zinc neodecanoate, and zinc naphthenate; organotin compounds such as stannous diacetate, stannous dioctanoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organonitrile compounds such as nickel octanoate and nickel naphthenate; organocobalt compounds such as cobalt octanoate and cobalt naphthenate; organobismuth compounds such as bismuth octanoate, bismuth neodecanoate, and bismuth naphthenate; tetraisopropoxytitanate, dibutyltitanium dichloride, tetrabutyl titanate, butoxytitanium trichloride; and titanium chelate complexes with at least one of aliphatic diketones, aromatic diketones, or alcohols having 2 to 10 carbon atoms as ligands.

[0129] Examples of amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinine ring, 2-methylquinine ring, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropanediamine, 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, and bis(di... Methylaminopropyl)isopropanolamine, 3-quinol, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazolium, 1,2-dimethylimidazolium, 1-isobutyl-2-methylimidazolium, 1-dimethylaminopropylimidazolium, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazolium, 1-(2-hydroxypropyl)imidazolium, 1-(2-hydroxyethyl)imidazolium, 1-(2-hydroxypropyl)imidazolium, 1-(2-hydroxyethyl)-2-methylimidazolium, 1-(2-hydroxypropyl)-2-methylimidazolium, etc.

[0130] Examples of aliphatic cyclic amide compounds include δ-valeramide, ε-caprolactam, ω-heptanolactam, η-octanolactam, and β-propiolactam. Among these, ε-caprolactam is more effective in promoting curing.

[0131] Examples of quaternary ammonium salts include hydroxyl salts, alkyl salts, and halide salts of alkylammonium and aromatic ammonium. Examples include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltriethylammonium chloride, and hexadecyltrimethylammonium bromide, but these are not the only examples.

[0132] (acid anhydride)

[0133] Examples of acid anhydrides include cyclic aliphatic anhydrides, aromatic anhydrides, and unsaturated carboxylic acid anhydrides. One type or a combination of two or more can be used. More specifically, examples include maleic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, dodecenyl succinic anhydride, polyadipic anhydride, polyazelic anhydride, polysaccharide anhydride, poly(ethyl octadecanoic acid) anhydride, poly(phenyl hexadecanoic acid) anhydride, tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, methyl humic anhydride, and trialkyl tetrahydrophthalic anhydride. Anhydrides, methylcyclohexene dicarboxylic anhydride, methylcyclohexene tetracarboxylic anhydride, ethylene glycol dipreptyltrimethyl ester dianhydride, chlorobridged anhydride, nadic anhydride, methylnadic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthous succinic anhydride, 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthous succinic anhydride, etc.

[0134] Alternatively, compounds obtained by modifying the above-mentioned compounds with diols can also be used as acid anhydrides. Examples of diols 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, copolymers of two or more of these diols and / or polyether glycols can also be used.

[0135] Alternatively, as the acid anhydride (B), homopolymers or copolymers of compounds with polymerizable unsaturated groups, such as maleic anhydride mentioned above, can also be used. Examples of compounds that can copolymerize with compounds having both anhydride and polymerizable unsaturated groups include: α-olefins such as ethylene, propylene, 1,3-butadiene, and cyclopentylethylene; (meth)acrylic acid monomers such as (meth)acrylic acid and (meth)acrylates; vinyl compounds with aromatic rings 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 fluorinated olefins such as fluorinated vinylidene, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene. One type can be used alone or in combination of two or more. Styrene and p-tert-butylstyrene, as vinyl compounds with aromatic rings, are preferred.

[0136] (Coupled agent)

[0137] Examples of coupling agents include silane coupling agents, titanate coupling agents, and aluminum coupling agents.

[0138] Examples of silane coupling agents include: γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, bis[3-(trimethoxysilyl)propyl]amine, bis[3-(triethoxysilyl)propyl]amine, etc.; β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropyltriethoxysilane, etc.; vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, etc.; hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, etc.

[0139] Examples of titanate-based coupling agents include tetraisopropoxy titanium, tetra-n-butoxy titanium, tetrabutyl titanate dimer, tetrastearate titanate, acetylacetone titanium, lactate titanium, tetraoctyl glycol titanate, lactate titanium, and tetrastearoxy titanium.

[0140] Examples of aluminum-based coupling agents include aluminum acetylalkoxydiisopropoxide.

[0141] (pigment)

[0142] There are no particular restrictions on pigments. Examples include extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metallic pigments, luminescent pigments, pearl pigments, and other organic, inorganic, and plastic pigments, as listed in the 1970 edition of the Paint Raw Materials Handbook (edited by the Japan Paint Industry Association).

[0143] Examples of pigments that can be categorized as body pigments include: precipitated barium sulfate, lead oxide, precipitated calcium carbonate, calcium bicarbonate, calcite, alumina white, silica, hydrated micronized silica (white carbon black), ultrafine anhydrous silica (AEROSIL), silica sand (silica sand), talc, precipitated magnesium carbonate, bentonite, clay, kaolin, loess, etc.

[0144] Specific examples of organic pigments include: various insoluble azo pigments such as benzidine yellow, Hansa yellow, and Lake red 4R; soluble azo pigments such as Lake red C, carmine 6B, and maroon 10; various (copper) phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; various basic dyeing lakes such as rhodamine lake and methyl violet lake; various mordant dyes such as quinoline lake and strong sky blue; various vat dyes such as anthraquinone pigments, thioindigo pigments, and violet ketone pigments; various quinacridone pigments such as precious violet red B; various dioxazine pigments such as dioxazine violet; various condensed azo pigments such as glutaryl violet; and aniline black, etc.

[0145] Inorganic pigments include: various chromates such as chrome yellow, zinc chromate, and molybdenum orange; various ferrocyanide compounds such as Prussian blue; various metal oxides such as titanium dioxide, zinc white, brownish yellow, iron oxide, iron oxide red, chrome oxide green, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercuric 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 violet; 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; mica-flake pigments coated with metal oxides, mica-like iron oxide pigments, and other metal pigments; pearlescent pigments; graphite, carbon black, etc.

[0146] Examples of plastic pigments include "GRANDOLL PP-1000" and "PP-2000S" manufactured by DIC Corporation.

[0147] The pigments used should be selected appropriately according to the purpose. For example, in terms of excellent durability, weather resistance, and appearance design, inorganic oxides such as titanium dioxide and zinc white are preferred as white pigments, and carbon black is preferred as black pigment.

[0148] Regarding the amount of pigment, as an example, it is 1 to 400 parts by mass relative to 100 parts by mass of the total amount of non-volatile components of the polyisocyanate composition (X) and the polyol composition (Y), and more preferably 10 to 300 parts by mass in order to improve adhesion and anti-blocking properties.

[0149] (Plasticizer)

[0150] Examples of plasticizers include phthalic acid-based plasticizers, fatty acid-based plasticizers, aromatic polycarboxylic acid-based plasticizers, phosphoric acid-based plasticizers, polyol-based plasticizers, epoxy-based plasticizers, polyester-based plasticizers, and carbonate-based plasticizers.

[0151] Examples of phthalic acid-based plasticizers include: 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, di(tridecyl) phthalate, di(undecyl) phthalate, and phthalic acid-based plasticizers. Phthalate ester plasticizers include dilaurate formate, distearate phthalate, diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, octyl decyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and diisooctyl isophthalate; tetrahydrophthalate ester plasticizers include di-(2-ethylhexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

[0152] Examples of fatty acid-based plasticizers include: di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diethylene glycol adipate; and azelaic acid-based plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, and diisooctyl azelate. Examples of sebacate-based plasticizers include dibutyl sebacate, di-(2-ethylhexyl) sebacate, and diisononyl sebacate; maleic acid-based plasticizers include dimethyl maleate, diethyl maleate, dibutyl maleate, and di-(2-ethylhexyl) maleate; fumarate-based plasticizers include dibutyl fumarate and di-(2-ethylhexyl) fumarate; and itaconic acid monomethyl ester and itaconic acid monomethyl ester. Plasticizers based on itaconic acid, such as monobutyl itaconic acid, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, and di-(2-ethylhexyl) itaconic acid; plasticizers based on stearic acid, such as n-butyl stearate, glyceryl monostearate, and diethylene glycol distearate; plasticizers based on oleic acid, such as butyl oleate, glyceryl monooleate, and diethylene glycol monooleate; plasticizers based on citric acid, such as triethyl citrate, tri-n-butyl citrate, triethyl acetyl citrate, tributyl acetyl citrate, and tri-(2-ethylhexyl) acetyl citrate; plasticizers based on ricinoleic acid, such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, glyceryl monoricinoleate, and diethylene glycol monoricinoleate; and other fatty acid plasticizers such as diethylene glycol monolaurate, diethylene glycol dinonanoate, and pentaerythritol fatty acid esters.

[0153] Examples of aromatic polycarboxylic acid plasticizers include: tri-n-hexyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, triisodecyl trimellitate, etc.; and pyromellitic acid plasticizers such as tetra-(2-ethylhexyl) pyromellitic acid and tetra-n-octyl pyromellitic acid.

[0154] Examples of phosphoric acid-based plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, triphenyl phosphate, octyl diphenyl phosphate, tolyl diphenyl phosphate, tolyl phenyl phosphate, tri(tolyl) phosphate, tri(xyl) phosphate, tri(chloroethyl) phosphate, tri(chloropropyl) phosphate, tri(dichloropropyl) phosphate, and tri(isopropylphenyl) phosphate.

[0155] Examples of polyol-based plasticizers include: diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexanoate), and dibutyl methylene bis(thioglycolic acid) ester; and glycerol-based plasticizers such as glyceryl monoacetate, glyceryl triacetate, and glyceryl tributyrate.

[0156] Examples of epoxy-based plasticizers include epoxidized soybean oil, epoxidized butyl stearate, epoxidized di(2-ethylhexyl) phthalate, epoxidized diisodecyl phthalate, epoxidized triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.

[0157] Examples of polyester plasticizers include adipic acid-based polyesters, sebacic acid-based polyesters, and phthalic acid-based polyesters.

[0158] Examples of carbonate-based plasticizers include propylene carbonate and ethylene carbonate.

[0159] In addition, other plasticizers include partially hydrogenated terphenyl, adhesive plasticizers, and polymeric plasticizers such as diallyl phthalate, acrylic monomers, or oligomers. These plasticizers can be used alone or in combination of two or more.

[0160] (Form of adhesive)

[0161] The two-component curing adhesive of the present invention can be in any form, either solvent-based or solvent-free. It should be noted that, in this specification, "solvent-based" adhesive refers to the form used in dry lamination, a method of bonding adhesive to other substrates after applying it to a substrate and heating it in an oven or similar environment to evaporate the organic solvent in the coating. Either or both of the polyisocyanate composition (X) and polyol composition (Y) contain an organic solvent capable of dissolving (diluting) the constituent components of the polyisocyanate composition (X) and polyol composition (Y) used in the present invention.

[0162] Examples of organic solvents include esters such as ethyl acetate, butyl acetate, and cellosol esters; 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 dichloromethane and dichloroethane; and dimethyl sulfoxide and dimethylsulfonamide. Organic solvents used as reaction media in the manufacture of polyisocyanate compositions (X) and polyol compositions (Y) are sometimes further used as diluents during coating processes.

[0163] In this specification, "solvent-free" adhesive refers to the form of adhesive used in the following method, also known as solvent-free lamination: the polyisocyanate composition (X) and polyol composition (Y) substantially do not contain esters such as ethyl acetate, butyl acetate, and cellosol esters; 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 dichloromethane and dichloroethane; highly soluble organic solvents such as dimethyl sulfoxide and dimethyl sulfonamide, especially ethyl acetate or methyl ethyl ketone; and after the adhesive is applied to the substrate, it is bonded to other substrates without a process of heating in an oven or similar means to evaporate the solvent. If trace amounts of organic solvent remain in the polyisocyanate composition (X) or polyol composition (Y) due to incomplete removal of the organic solvents used as reaction media during the manufacture of the raw materials, it can be understood as substantially free of organic solvents. Furthermore, when the polyol composition (Y) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the polyisocyanate composition (X) to become part of the coating film, thus eliminating the need for post-coating evaporation. Therefore, this form is also treated as a solvent-free adhesive, and the low molecular weight alcohol is not considered an organic solvent.

[0164] The two-component curing adhesive of the present invention is preferably used in such a manner that the ratio of the molar number of isocyanate groups [NCO] contained in the polyisocyanate composition (X) to the molar number of hydroxyl groups [OH] contained in the polyol composition (Y) [NCO] / [OH] 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 ambient humidity at the time of application.

[0165] <Layered Body>

[0166] The laminate of the present invention can be obtained, for example, by a method having a two-component mixing step or a method having a two-component separate coating step. In the two-component mixing step, the polyisocyanate composition (X) and the polyol composition (Y) are mixed beforehand and then coated onto a first substrate. A second substrate is then laminated onto the coated surface, and the adhesive layer is cured. In the two-component separate coating step, the polyisocyanate composition (X) and the polyol composition (Y) are respectively coated onto the first substrate and the second substrate, and their respective coated surfaces are brought into contact and pressed together, thereby laminating the first substrate and the second substrate and curing the adhesive layer. There are no particular limitations on the film used; a film appropriate for the application can be selected.

[0167] 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 stretched polyethylene film, OPE: biaxially stretched polyethylene film), polypropylene film (CPP: unstretched polypropylene film, OPP: biaxially stretched polypropylene film), and gas-barrier heat-sealing film made by setting an olefin-based heat-sealing resin layer on one or both sides of an ethylene-vinyl alcohol copolymer, polyvinyl alcohol, or other gas-barrier resin.

[0168] In addition, biomass films, biodegradable films, and recycled plastic films formed from materials containing biomass-derived components, biodegradable components, or recycled components are preferred.

[0169] In addition to being sold by individual companies, biomass films, biodegradable films, and recycled plastic films can also be certified by various countries, such as those listed in the list of biomass certified products recorded by the Japan Organic Resources Association, those listed in the list of green label certified products recorded by the Japan Environment Association, and those bearing the symbol designated by the Japan Bioplastics Association.

[0170] (Biofilm)

[0171] As a known specific example of a biomass membrane, one can cite a biomass membrane using biomass-derived ethylene glycol as a raw material. Biomass-derived ethylene glycol uses ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained using conventionally known methods, such as methods for producing ethylene glycol from ethylene oxide. Alternatively, commercially available biomass ethylene glycol can be used; for example, biomass ethylene glycol sold by India Glycols Co., Ltd. can be appropriately used.

[0172] For example, as a replacement for conventional polyethylene terephthalate membranes that use petroleum-based raw materials, membranes containing biomass polyesters and biomass polyethylene terephthalate are known.

[0173] The dicarboxylic acid units of biomass polyesters use dicarboxylic acids derived from fossil fuels. Aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their derivatives can be used without restriction as dicarboxylic acids.

[0174] Alternatively, a copolyester can be obtained by adding a third component, selected from diol and dicarboxylic acid components, as a copolymer component, including at least one polyfunctional compound selected from difunctional hydroxycarboxylic acid, polyvalent alcohols with three or more functions used to form a crosslinking structure, polycarboxylic acid with three or more functions and / or its anhydrides, and hydroxycarboxylic acid with three or more functions.

[0175] In addition, as alternatives to conventional polyolefin membranes that use petroleum-based raw materials, biomass polyolefin membranes, such as biomass polyethylene membranes and biomass polyethylene-polypropylene membranes, are also known.

[0176] Polyethylene resins are not particularly limited except for the use of ethylene glycol from the aforementioned biomass source in a portion of the raw materials. Examples include homopolymers of ethylene, copolymers of ethylene and α-olefins with ethylene as the main component (ethylene-α-olefin copolymers containing more than 90% by mass of ethylene units), etc., and one of them can be used alone or in combination of two or more.

[0177] It should be noted that the α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and examples include α-olefins with 4 to 8 carbon atoms such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Known polyethylene resins such as low-density polyethylene resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used. From the viewpoint of reducing the likelihood of damage such as pores and cracks even when friction occurs between the films, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferred, and a density of 0.910 to 0.925 g / cm³ is more preferred. 3 Linear low-density polyethylene resin.

[0178] Biomass membranes using biomass raw materials classified according to the biomass plasticity standards specified in ISO 16620 or ASTM D6866 are also circulating. Radioactive carbon-14C exists in the atmosphere at a ratio of 1 in 10¹², a ratio that remains constant in atmospheric carbon dioxide, and therefore also remains constant in plants that have immobilized this carbon dioxide through photosynthesis. Therefore, plant-derived resins contain radioactive carbon-14C. In contrast, fossil fuel-derived resins contain virtually no radioactive carbon-14C. Therefore, by determining the concentration of radioactive carbon-14C in the resin using an accelerator mass spectrometer, the proportion of plant-derived resin in the resin, i.e., the biomass plasticity, can be determined.

[0179] Plant-derived low-density polyethylene, which falls under the category of biomass plasticity of 80% or more, preferably 90% or more, as specified in ISO 16620 or ASTM D6866, such as the trade names "SBC818", "SPB608", "SBF0323HC", "STN7006", "SEB853", and "SPB681" manufactured by Braskem, can be suitably used as a raw material for membranes.

[0180] In addition, films and sheets containing starch and polylactic acid as biomass raw materials are also known. These can be selected appropriately according to the intended use.

[0181] Biomass membranes can be laminates of multiple biomass membranes, or they can be laminates of conventional petroleum-based membranes and biomass membranes. Furthermore, these biomass membranes can be unstretched or stretched membranes, and their manufacturing method is not limited.

[0182] (Biodegradable membrane)

[0183] Specific examples of known biodegradable membranes include those made from widely available biodegradable resins. Examples include polycaprolactone, polyvinyl alcohol, polyamide, cellulose esters, lactic acid polyester resins, aliphatic polyester resins, and aliphatic aromatic polyester resins. These biodegradable resins can be used alone or in combination of two or more. Aliphatic polyester resins or aliphatic aromatic polyester resins are preferred.

[0184] Aliphatic polyester resins include aliphatic polyesters obtained by the polycondensation reaction of aliphatic diols with aliphatic dicarboxylic acids. Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanediol. These can be used alone or in mixtures. 1,4-Butanediol is preferred. Examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, octanoic acid, and dodecanoic acid; anhydrides derived from these can also be used. Succinic acid or succinic anhydride, or mixtures thereof with adipic acid, are preferred.

[0185] Specifically, examples include polybutylene succinate (PBS) obtained from 1,4-butanediol and succinic acid (e.g., BioPBS prepared by PPT MCC BIOCHEM), and polybutylene adipate (PBSA) obtained by copolymerizing adipate with PBS.

[0186] Examples of aliphatic aromatic polyester resins include copolymers comprising aliphatic dicarboxylic acid units, aromatic dicarboxylic acid units, and chain-like aliphatic and / or alicyclic diol units. The diol component forming the diol unit is typically a diol with 2 to 10 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,4-cyclohexanediol. Diols with 2 to 4 carbon atoms are preferred, with ethylene glycol and 1,4-butanediol being more preferred, and 1,4-butanediol being more preferred. The dicarboxylic acid component forming the dicarboxylic acid unit is typically a dicarboxylic acid with 2 to 10 carbon atoms, such as succinic acid, adipic acid, octanoic acid, sebacic acid, and dodecanoic acid. Succinic acid or adipic acid is preferred. Examples of aromatic dicarboxylic acid components forming the aromatic dicarboxylic acid unit include terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid. Among them, terephthalic acid and isophthalic acid are preferred, and terephthalic acid is more preferred.

[0187] Specifically, examples include PBAT, which is a copolymer of 1,4-butanediol, adipic acid, and terephthalic acid (e.g., Ecoflex manufactured by BASF).

[0188] Other examples include poly(3-hydroxyalkanoates) of aliphatic polyester copolymers obtained from hydroxyalkanoates and polycarboxylic acids (such as poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) (e.g., AONILEX from Kaneka Corporation), and polylactic acid (PLA) (e.g., REVODE from Hisun Biomaterials and Ingeo from Nature Works).

[0189] Biodegradable membranes can be laminates of multiple biodegradable membranes, or laminates of conventional petroleum-based membranes and biodegradable membranes. Furthermore, these biodegradable membranes can be unstretched or stretched membranes, and their manufacturing method is not limited.

[0190] The film can be a film that has undergone stretching treatment. As a stretching treatment method, resin is typically melted and extruded into a sheet using methods such as extrusion film forming, followed by simultaneous biaxial stretching or successive biaxial stretching. In the case of successive biaxial stretching, longitudinal stretching is usually performed first, followed by transverse stretching. Specifically, a method combining longitudinal stretching utilizing the speed difference between rollers with transverse stretching using a tenter frame is often used.

[0191] In order to form an adhesive layer free from defects such as film fracture and shrinkage cavities, various surface treatments such as flame treatment and corona discharge treatment can be applied to the film surface as needed.

[0192] Alternatively, a membrane with vapor-deposited layers of metals such as aluminum, silicon dioxide, or alumina, or a barrier membrane containing gas barrier layers such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or vinylidene chloride can be used. By using such membranes, a laminate with barrier properties against water vapor, oxygen, alcohols, inactive gases, and volatile organic compounds (aromas) can be produced.

[0193] There are no particular limitations on the paper itself; any known paper substrate can be used. Specifically, it can be manufactured using natural papermaking fibers such as wood pulp and a known papermaking machine, with no particular requirements for the papermaking conditions. Examples of natural papermaking fibers include wood pulps such as softwood pulp and hardwood pulp, non-wood pulps such as Manila hemp pulp, sisal pulp, and flax pulp, as well as pulps obtained by chemically modifying these pulps. As for the type of pulp, chemical pulps based on sulfate hydrolysis, acid / neutral / alkaline sulfite hydrolysis, sodium salt hydrolysis, etc., as well as milled pulps, chemi-milled pulps, and thermomechanical pulps can be used. Additionally, various commercially available high-quality papers, coated paper, lining paper, impregnated paper, cardboard, and paperboard can also be used.

[0194] As a more specific example of the composition of a stacked body, the following can be cited:

[0195] (1) Substrate 1 / Adhesive layer 1 / Sealing film

[0196] (2) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited unstretched film

[0197] (3) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretch film

[0198] (4) Transparent vapor-deposited stretch film / adhesive layer 1 / sealing film

[0199] (5) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Sealing film

[0200] (6) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretch film / Adhesive layer 2 / Sealing film

[0201] (7) Substrate 1 / Adhesive layer 1 / Transparent vapor-deposited stretch film / Adhesive layer 2 / Sealing film

[0202] (8) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Sealing film

[0203] (9) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Metal layer / Adhesive layer 3 / Sealing film

[0204] (10) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Substrate 2 / Adhesive layer 3 / Sealing film, etc., but not limited to these.

[0205] Examples of substrate 1 used in composition (1) include MDOPE film, OPE film, OPP film, PET film, nylon film, and paper. Alternatively, substrate 1 may be a material that has been coated to improve gas barrier properties and ink receptivity when the printing layer described later is applied. Commercially available examples of coated substrate films 1 include K-OPP film, K-PET film, and K-nylon film. Adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealing films include CPP film, LLDPE film, easy-open heat-sealable film, and gas-barrier heat-sealable film. The printing layer may be applied to the adhesive layer 1 side of substrate 1 (or the adhesive layer 1 side of the coating layer when using a coated material as substrate film 1) or the side opposite to adhesive layer 1. The printing layer is formed using various printing inks such as gravure ink, flexographic ink, offset ink, screen ink, and inkjet ink, and through conventional printing methods previously used for printing on polymer films and paper.

[0206] Examples of substrate 1 used in components (2) and (3) include MDOPE film, OPE film, OPP film, PET film, and paper. The adhesive layer 1 is a cured coating of the adhesive of the present invention. As a metal vapor-deposited unstretched film, VM-CPP film and VM-LLDPE film obtained by vapor deposition of metals such as aluminum on CPP film, LLDPE film, and gas barrier heat-sealing film can be used. As a metal vapor-deposited stretched film, VM-MDOPE film, VM-OPE film, and VM-OPP film obtained by vapor deposition of metals such as aluminum on MDOPE film, OPE film, and OPP film can be used. A printing layer may also be provided on any side of substrate 1, similar to component (1).

[0207] As the transparent vapor-deposited stretch film used in configuration (4), examples include films obtained by vapor deposition of silicon dioxide or aluminum oxide onto MDOPE films, OPE films, OPP films, PET films, nylon films, etc. Films obtained by coating an inorganic vapor-deposited layer with silicon dioxide or aluminum oxide for purposes such as protection can also be used. Adhesive layer 1 is a cured coating of the adhesive of the present invention. Sealing film can be the same as that in configuration (1). A printing layer can also be provided on the adhesive layer 1 side of the transparent vapor-deposited stretch film (or, when using a material obtained by coating an inorganic vapor-deposited layer, the adhesive layer 1 side of the coating layer). The method for forming the printing layer is the same as in configuration (1).

[0208] Examples of substrate 1 used in configuration (5) include PET film and paper. Examples of substrate 2 include nylon film. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating of the adhesive of the present invention. Examples of sealing film are the same as those in configuration (1). A printed layer may also be provided on either side of substrate 1, as in configuration (1).

[0209] As the substrate 1 of configuration (6), examples can be the same substrates as those in configurations (2) and (3). As the metal vapor-deposited stretch film, examples can be VM-MDOPE film, VM-OPE film, VM-OPP film, and VM-PET film obtained by vapor deposition of metals such as aluminum onto MDOPE film, OPE film, OPP film, and PET film. At least one of adhesive layer 1 and adhesive layer 2 is a cured coating of the adhesive of the present invention. Examples of sealing films can be the same as those in configuration (1). A printing layer can also be provided on any side of the substrate 1, similar to configuration (1).

[0210] Examples of substrate 1 in component (7) include PET film and paper. Examples of transparent vapor-deposited stretch film include the same transparent vapor-deposited stretch film as in component (4). At least one of adhesive layers 1 and 2 is a cured coating of the adhesive of the present invention. Examples of sealing film include the same sealing film as in component (1). A printed layer may also be provided on either side of substrate 1, similar to component (1).

[0211] Examples of substrate 1 in component (8) include PET film and paper. Examples of metal layers include aluminum foil. At least one of adhesive layers 1 and 2 is a cured coating of the adhesive of the present invention. Examples of sealing films are the same as those in component (1). A printed layer may also be provided on either side of substrate 1, similar to component (1).

[0212] Examples of substrate 1 in components (9) and (10) include PET film and paper. Examples of substrate 2 include nylon film. Examples of metal layer include aluminum foil. At least one of adhesive layers 1, 2, and 3 is a cured coating of the adhesive of the present invention. Examples of sealing film are the same as those in component (1). A printed layer may also be provided on any side of substrate 1, similar to component (1).

[0213] The adhesive of the present invention exhibits excellent adhesion to metal substrates and metal vapor-deposited layers, and is therefore particularly suitable for manufacturing components (2), (3), (6), (8) to (10). Among these components, the adhesive layer in contact with the metal substrate and the metal vapor-deposited layer is preferably a cured coating of the adhesive of the present invention.

[0214] When using the adhesive of the present invention as an adhesive aid, the adhesive aid of the present invention is applied to the film material that serves as the substrate using a gravure roller or similar roller. After the organic solvent is evaporated by heating in an oven or similar place, the molten polymer material is laminated using an extruder, thereby obtaining the laminate of the present invention.

[0215] The laminate of the present invention may further include other films and substrates in addition to the above-described components (1) to (10). Other substrates may include porous substrates such as paper, wood, and leather, in addition to the above-described stretched film, unstretched film, and transparent vapor-deposited film. The adhesive used when bonding other substrates may or may not be the adhesive of the present invention.

[0216] "Other layers" may include known additives, stabilizers, such as antistatic agents, easy-to-adhere coating agents, plasticizers, lubricants, antioxidants, etc. In addition, "other layers" may also be layers in which the surface of the film has undergone corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc., as a pretreatment to improve the adhesion when laminated with other materials.

[0217] The laminate of the present invention can be suitably used for various purposes, such as: packaging materials for food, medicine, and daily necessities; lids; paper tableware such as paper straws, paper towels, paper spoons, paper plates, and paper cups; barrier wall materials; roofing materials; solar cell panel materials; battery packaging materials; window materials; outdoor flooring materials; lighting protection materials; automotive components; billboards; posters and other outdoor industrial applications; decorative sheets used in injection molding and decoration methods; packaging materials for liquid detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, and liquid conditioners, etc.

[0218] Packaging Materials

[0219] The laminated body of the present invention can be used as a multi-layer packaging material for the purpose of protecting food, pharmaceuticals, etc. When used as a multi-layer packaging material, its layer composition can be changed according to the contents, usage environment, and usage pattern. Furthermore, the packaging body of the present invention can be appropriately equipped with easy-opening and resealing mechanisms.

[0220] As an example of a specific packaging material of the present invention, a packaging material made by forming a bag with a sealing film, as described in the above-mentioned examples (1), (4) to (10) of the laminated body composition, can be cited. The laminated body is folded or overlapped so that the inner surfaces (the surfaces of the sealing film) face each other, and its peripheral ends are heat-sealed to form a bag shape. As a bag-making method, heat-sealing methods using side-seal, two-side-seal, three-side-seal, four-side-seal, envelope-type sealing, clasp-type sealing, pleated sealing, flat-bottom sealing, square-bottom sealing, gusset type, and other heat-sealing methods can be cited. The packaging material of the present invention can take various forms depending on the contents, the usage environment, and the usage form. It can also be a self-standing packaging material (stand-up pouch), etc. As a heat-sealing method, known methods such as stick sealing, rotary roller sealing, belt sealing, instant heat sealing, high-frequency sealing, and ultrasonic sealing can be cited.

[0221] The packaging material of the present invention is used to manufacture products by heat-sealing the opening after filling it with contents. Examples of the contents include, for instance, food items such as: rice cakes, bean curd, nuts, biscuits, wafers, marshmallows, pies, semi-baked cakes, candies, snacks, and other confectionery; bread, instant noodles, dried noodles, pasta, aseptically packaged rice, Japanese risotto, porridge, packaged rice cakes, oatmeal, and other staple foods; pickles, boiled beans, natto, miso, frozen tofu, tofu, shiitake mushrooms, konjac, processed mountain vegetables, jams, peanut butter, salads, frozen vegetables, processed potato products, and other agricultural processed products; ham, bacon, sausages, processed chicken products, and cured beef products. Animal products processed into various categories, including: fish, ham / sausage, fish paste, fish cake, seaweed, oden, dried bonito, pickled fish, smoked salmon, and spicy mentaiko; fruits and meats such as peaches, oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; cooked foods such as frozen and refrigerated side dishes, including hamburgers, meatballs, fried seafood, dumplings, and croquettes; dairy products such as cream, margarine, cheese, whipped cream, instant creamer, and infant formula; and food products such as liquid seasonings, ready-to-eat curry, and pet food.

[0222] In addition, for non-food items, it can also be used as packaging material for various products such as cigarettes, disposable hand warmers, infusion bags and other medical supplies, liquid detergents for washing, liquid detergents for kitchens, liquid detergents for bathing, liquid soaps for bathing, liquid shampoos, liquid conditioners, lotions and other cosmetics, vacuum insulation materials, and batteries.

[0223] Example

[0224] The present invention will be described in more detail below with specific examples of synthesis and embodiments, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise specified, "parts" and "%" in the following examples represent "parts by mass" and "% by mass", respectively.

[0225] <Polyurethane polyisocyanate (A1)>

[0226] (Example 1)

[0227] (Polyurethane polyisocyanate (A1-1))

[0228] (Process (1))

[0229] 185 parts of toluene diisocyanate (TDI), 15 parts of difunctional polypropylene glycol (DOW VORANOL 2120, hereinafter referred to as PPG2000D) with a molecular weight of 2000 g / mol, 60 parts of difunctional polypropylene glycol (AGC EXCENOL 1020, hereinafter referred to as PPG1000D) with a molecular weight of 1000 g / mol, 85 g of difunctional polyethylene glycol (Sanyo Chemicals, hereinafter referred to as PEG400D) with a molecular weight of 400 g / mol, and 0.13 parts of polyphosphoric acid (containing 5% of the degree of polymerization n = 2 to 5) were continuously reacted under a nitrogen stream until the NCO% did not change at 80°C, to obtain a composition containing polyurethane polyisocyanate (A1-1) and unreacted TDI.

[0230] (Process (2))

[0231] The resulting composition was transferred to a thin-film distillation apparatus and purified at a pressure of approximately 0.02 Torr and a temperature of 150°C until the TDI in the composition reached 0.06% by mass, thereby obtaining the polyisocyanate composition (X-1). The calculated polyphosphoric acid content was 500 ppm of polyurethane polyisocyanate (A1-1).

[0232] (Example 2) to (Example 8)

[0233] (Polyurethane polyisocyanates (A1-2) ~ (A1-8))

[0234] Except for changing the raw materials and polyphosphoric acid content to those listed in Table 1, polyurethane polyisocyanates (A1-2) to (A1-8) were obtained using the same method as polyurethane polyisocyanate (A1-1).

[0235] (Comparative Example 1) to (Comparative Example 8)

[0236] (Polyurethane polyisocyanates (A1'-1) ~ (A1'-8))

[0237] Except for changing the raw materials and polyphosphoric acid content to those recorded in Table 2, polyurethane polyisocyanates (A1'-1) to (A1'-8) were obtained using the same method as polyurethane polyisocyanate (A1-1).

[0238] It should be noted that the details of the compounds in Tables 1 and 2 are as follows.

[0239] TDI: Toluene diisocyanate

[0240] HDI: Hexamethylene diisocyanate

[0241] MDI50: Diphenylmethane diisocyanate (a mixture of isomers of 4,4'-MDI and 2,4'-MDI)

[0242] PPG400D: Difunctional polypropylene glycol with a molecular weight of 400 g / mol.

[0243] PPG1000D: Difunctional polypropylene glycol with a molecular weight of 1000 g / mol.

[0244] PPG2000D: Difunctional polypropylene glycol with a molecular weight of 2000 g / mol.

[0245] In addition, the “content rate (%) of n = 2 to 5” in Tables 1 and 2 is the proportion of compound (B1) in the polyphosphoric acid (B) used in the synthesis.

[0246] [Table 1]

[0247]

[0248] [Table 2]

[0249]

[0250] <Evaluation>

[0251] (Gardner Chromatography)

[0252] The composition after step (1) and the polyurethane polyisocyanate (A1) after step (2) were collected in flat-bottomed, colorless hard glass test tubes with an inner diameter of 10.75±0.1 mm and a length of 112±1 mm, respectively. Gardner colorimetry was determined using a TZ-6000 manufactured by Nippon Denshoku Kogyo Co., Ltd. The results were evaluated according to the following criteria in four grades and summarized in Tables 3 and 4.

[0253] 〇: Less than 3

[0254] △: 3 or more and less than 4

[0255] ×: 4 or more and less than 6

[0256] ××:6 or above

[0257] (NCO%)

[0258] Weigh 5g of the sample into a clean, dry 300mL Erlenmeyer flask. Add 15mL of ethyl acetate (dehydrated) using a graduated cylinder to dissolve the sample. After complete dissolution, add 10mL of 1mol / L di-n-butylamine toluene solution using a Hall pipette, mix thoroughly, and let stand at room temperature for at least 20 minutes. Then, add approximately 30mL of methanol using a graduated cylinder. Add 7-8 drops of bromophenol blue indicator and titrate with 0.5mol / L hydrochloric acid aqueous solution, using the time point from purple to yellow as the endpoint. Simultaneously perform a blank test. Calculate the NCO% (measured value) according to the following formula, rounding to the second decimal place as the measured value.

[0259] [Mathematical Expression 1]

[0260]

[0261] B: Titration volume (mL) of 0.5 mol / L hydrochloric acid aqueous solution required for the blank test.

[0262] T: The titration volume (mL) of the 0.5 mol / L hydrochloric acid aqueous solution required for this experiment.

[0263] F: Titration rate of 0.5 mol / L hydrochloric acid aqueous solution

[0264] S: Sample collection volume (g)

[0265] Furthermore, based on the amounts of isocyanate and polyol added in the synthesis of polyurethane polyisocyanate (A1), the theoretical NCO% was calculated assuming that an equimolar amount of isocyanate reacted relative to the hydroxyl groups of the polyol (since the reaction occurs in a system with an excess of isocyanate groups relative to the hydroxyl groups, the formation of urethane bonds at the molar end of the isocyanate does not occur). The measured NCO% was compared with the theoretical NCO% and evaluated on a three-tiered scale according to the following evaluation criteria. The results are summarized in Tables 3-4.

[0266] 〇: The difference between the theoretical value and the measured value is less than 0.2%.

[0267] △: The difference between the theoretical value and the measured value is greater than 0.2% but less than 0.4%.

[0268] ×: The difference between the theoretical value and the measured value is greater than 0.4%.

[0269] [Table 3]

[0270]

[0271] [Table 4]

[0272]

[0273] <Adhesive>

[0274] (Preparation of adhesive)

[0275] Polyurethane polyisocyanate (A1-1) was designated as polyisocyanate composition (X-1), and a mixture of polyester polyol with a molecular weight of 600 g / mol and DESMOPEN 4051B (manufactured by COVESTRO) at a mass ratio of 94:6 was designated as polyol composition (Y). The two-component curing adhesive of Example 1 was prepared by mixing the two components according to the proportions shown in Table 5.

[0276] Polyurethane polyisocyanates (A1-2) to (A1-8) and (A1'-1) to (A1'-8) were respectively designated as polyisocyanate compositions (X-2) to (X-8) and (X'-1) to (X'-8). Otherwise, the same procedure as in Example 1 was followed, and the adhesives of Examples 2 to 8 and Comparative Examples 1 to 8 were prepared by mixing them according to the proportions shown in Tables 5 and 6.

[0277] <Evaluation of Adhesives>

[0278] (The color tone of the layered body)

[0279] Using a laminator set to a lamination speed of 150 m / min, the prepared adhesive was applied to a plain-colored stretched polypropylene film, with a coating weight of 2.0 g / m. 2 The film was then laminated with an unstretched polypropylene film and aged at 40°C for 3 days to produce an evaluation laminate.

[0280] The prepared laminate was cut into 15cm x 15cm strips and fixed onto white copy paper (Nippon Paper Corporation CHW-A4) using adhesive tape. The tones were visually evaluated, and the results are summarized in Tables 5 and 6.

[0281] 〇: Colorless

[0282] △: Slightly yellow

[0283] ×: Yellowing

[0284] ××: Dark yellow

[0285] (The production of printed materials)

[0286] The urethane-based laminated ink (Finart R794 White G3; manufactured by DIC Co., Ltd.) was adjusted to 15 seconds (25°C) based on ZAHN CUP#3 manufactured by Lihe Co., Ltd., and printed onto a corona-treated PET (polyethylene terephthalate) film (Toyobo E5102, 12μm thick) at a printing speed of 150m / min using a gravure printing press equipped with a 43μm deep gravure plate. The film was then dried or cured in a 70°C oven, forming a printed layer on the PET film.

[0287] (Preparation of samples for evaluating bond strength)

[0288] Using a solvent-free testing coating machine, the coating amount was set to 2.0 g / m² on the surface of the printed layer on the PET film. 2 The prepared adhesive was applied at a coating speed of 150 m / min, and an aluminum vapor-deposited non-stretched polypropylene film (hereinafter referred to as VMCPP, thickness 25 μm) was overlapped and bonded onto the coated surface. Then, the adhesive was cured for 3 days at 40°C and 50% RH, resulting in a laminate consisting of PET / printed layer / adhesive layer / VMCPP, which was used for evaluation as sample 1.

[0289] (Evaluation of bond strength 1)

[0290] Evaluation sample 1 was cut into pieces 300 mm in length and 15 mm in width, and used as specimens. Using an Instron tensile testing machine, tensile testing was performed at 25°C and a peel speed of 300 mm / min. The T-peel strength (N) between PET and VMCPP was measured over a 15 mm width. This test was performed five times, and the average value was calculated. The results were evaluated according to the following criteria, and summarized in Tables 5 and 6 as adhesive strength 1.

[0291] 〇:1.5N or more

[0292] △: 1.0N or more but less than 1.5N

[0293] ×: Less than 1.0N

[0294] (Fabrication of composite membrane)

[0295] Using a solvent-free testing coating machine, a coating of 2.0 g / m² was achieved on a PET film (Toyobo E5102, 12 μm thickness). 2 The prepared adhesive was applied by means of a clamping roller (50°C) and pressed onto an aluminum foil (hereinafter referred to as AL, 9 μm thick). Then, an adhesive was applied to the aluminum foil at a concentration of 2.0 g / m². 2The prepared adhesive was applied by coating and then pressed onto a polyethylene film (LLDPE, TUX-HC manufactured by Mitsui Chemicals Tohcello Co., Ltd., 60 μm thick) using a clamping roller (50°C). After aging at 40°C for 3 days, a laminate consisting of PET / adhesive layer / AL / adhesive layer / LLDPE was produced, resulting in evaluation sample 2.

[0296] (Evaluation of bond strength 2)

[0297] Evaluation sample 2 was cut into pieces 300 mm in length and 15 mm in width, and used as specimens. Using an Instron tensile testing machine, tensile testing was performed at 25°C and a peel speed of 300 mm / min. The T-peel strength (N) between AL and LLDPE was determined over a 15 mm width. This test was performed five times, and the average value was calculated. The results were evaluated according to the following criteria, and summarized in Tables 5-6 as adhesive strength 2.

[0298] 〇:5.5N or more

[0299] △: 5.0N or more but less than 5.5N

[0300] ×: Less than 5.0N

[0301] [Table 5]

[0302]

[0303] [Table 6]

[0304]

Claims

1. A two-component curing adhesive comprising a polyisocyanate composition (X) and a polyol composition (Y). The polyisocyanate composition (X) comprises polyurethane polyisocyanate (A1), diisocyanate monomer (A2), and polyphosphoric acid (B). The diisocyanate monomer (A2) accounts for less than 0.1% by mass in the polyisocyanate composition (X). The ratio of polyphosphoric acid (B) to polyurethane polyisocyanate (A1) is more than 100 ppm and less than 5000 ppm.

2. The two-component curing adhesive according to claim 1, wherein, The polyphosphoric acid (B) comprises the compound (B1) shown in formula (1). In equation (1), n ​​is a natural number greater than 2 and less than 5.

3. The two-component curing adhesive according to claim 1, wherein, The compound (B1) accounts for more than 5% by mass and less than 70% by mass in the polyphosphoric acid (B).

4. The two-component curing adhesive according to claim 1, wherein, The polyurethane polyisocyanate (A1) is a reaction product of diisocyanate monomer and polyol compound, wherein the polyol compound includes polyether polyol.

5. The two-component curing adhesive according to claim 1, wherein, The polyurethane polyisocyanate (A1) is obtained through the following processes (1) and (2). The step (1) is a step in which the diisocyanate monomer is reacted with the polyol compound in the presence of the polyphosphoric acid (B). Step (2) is a step of removing unreacted diisocyanate monomers from the composition obtained in step (1).

6. The two-component curing adhesive according to claim 1, wherein, The polyol composition (Y) comprises a polyol compound (C), which comprises at least one selected from polyether polyols (C1), polyols having tertiary amino groups (C2), and polyester polyols (C3).

7. The two-component curing adhesive according to claim 6, wherein, The content of the polyol (C2) having a tertiary amino group in the polyol compound (C) is more than 1% by mass and less than 50% by mass.

8. A laminate comprising a first substrate, a second substrate, and an adhesive layer for bonding the first substrate and the second substrate, wherein the adhesive layer is a cured coating of a two-component curable adhesive as described in any one of claims 1 to 7.

9. The laminate according to claim 8, wherein, A metal foil or a metal vapor-deposited layer is disposed between the first substrate and the adhesive layer.

10. A packaging material comprising the laminate of claim 8.

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