AU2022219748A1 - Adhesive, laminate, and packaging material - Google Patents

Abstract

Provided are: a solvent-free adhesive which has excellent resistance to the contents and is less apt to redissolve print layers; and a laminate and a packaging material both obtained using the adhesive.　The solvent-free adhesive comprises a polyol composition (X) and a polyisocyanate composition (Y), wherein the polyol composition (X) has a number-average molecular weight of 450-1000 and comprises a polyol (A) which is a tetra- or higher-functional sugar alcohol derivative and a polyester polyol (B) which is a reaction product obtained from a composition comprising a polyhydric alcohol and a polycarboxylic acid, the proportion of the polyol (A) in the sum of the polyol (A) and the polyester polyol (B) being 5-30 mass%.

Description

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DESCRIPTION TITLE OF INVENTION: ADHESIVE, LAMINATE, AND PACKAGING MATERIAL TECHNICAL FIELD

[0001] The present invention relates to an adhesive, a laminate to be obtained by using the adhesive, and a packaging material.

BACKGROUND ART

[0002] Designability, functionality, preservability, convenience, and transportability are imparted to a laminate used in various packaging materials, labels, and the like, by laminating a base material such as various plastic films, metal foils, and paper, and in particular, a package obtained by molding the laminate into the shape of a bag is used as a package for food, a medicine, a detergent, and the like.

[0003] In the related art, the laminate used in the package was mainly obtained by a dry lamination method in which the base material is coated with an adhesive dissolved in a volatile organic solvent (may be referred to as a solvent-type laminating adhesive), the organic solvent is volatilized in a process of passing through an oven, and another base material is pasted, but recently, a demand for a reactive two-pack type laminating adhesive (hereinafter, referred to as a solvent-free adhesive), which does not contain the volatile organic solvent, has increased from the viewpoint of reducing an environmental load and improving a work environment (PTL 1).

CITATION LIST PATENT LITERATURE

[0004] PTL 1: JP2014-159548A

SUMMARY OF INVENTION TECHNICAL PROBLEM

[0005] The solvent-free adhesive has many advantages that there is no dry step and no solvent to be discharged, a running cost is reasonable with energy conservation, and there is no concern that the solvent remains in the laminate after pasting the plastic films with each other or the laminate after pasting the plastic film and the metal foil or a metal vapor deposition layer, but also has disadvantages.

[0006] It is necessary to design components used in the solvent-free adhesive to have a low molecular weight such that a viscosity is obtained at which coating can be performed when heated to approximately 40°C to 100°C. Accordingly, the solvent-free adhesive tends to have degraded content resistance with respect to content such as a shampoo or a conditioner, which penetrates through a sealant film and affects an adhesive layer (a cured coating film of the adhesive). In addition, in the laminate for a packaging material, in general, a printing layer is provided on the back side (the content side) of the base material to be the outermost layer (when seen from the content) with a printing ink, and the printing layer and another base material are pasted through the adhesive, but some solvent-free adhesives containing low molecular-weight polyester polyol may be likely to re-dissolve the printing layer.

[0007] The invention has been made in consideration of such circumstances, and an object thereof is to provide a solvent-free adhesive that is excellent in content resistance and is less likely to re-dissolve a printing layer, a laminate obtained by using the adhesive, and a packaging material.

SOLUTION TO PROBLEM

[0008] The invention relates to a solvent-free adhesive, containing: a polyol composition (X); and a polyisocyanate composition (Y), in which the polyol composition (X) has a number average molecular weight of 450 or more 1000 or less, and contains polyol (A), which is a tetrafunctional or higher sugar alcohol derivative, and polyester polyol (B), which is a reaction product of a composition containing polyhydric alcohol and a polycarboxylic acid, and the polyol (A) has a compound amount of 5% by mass or more and 30% by mass or less with respect to a total amount of the polyol (A) and the polyester polyol (B).

[0009]

Further, the invention relates to a laminate including: a first base material; a second base material; and an adhesive layer for pasting the first base material and the second base material, in which the adhesive layer is a cured coating film of the two-pack curable adhesive described above, and a packaging material including the laminate.

ADVANTAGEOUS EFFECTS OF INVENTION

[0010] According to the adhesive of the invention, it is possible to provide the solvent-free adhesive that is excellent in the content resistance and is less likely to re-dissolve the printing layer, the laminate excellent in the content resistance and a printing appearance, and the packaging material.

DESCRIPTION OF EMBODIMENTS

[0011] <Adhesive> The adhesive of the invention is a two-pack curable adhesive containing a polyol composition (X) and a polyisocyanate composition (Y). Hereinafter, the adhesive of the invention will be described in detail.

[0012] (Polyol Composition (X)) (Polyol (A)) The polyol composition (X) used in the adhesive of the invention has a number average molecular weight of 450 or more 1000 or less, and contains polyol (A), which is a tetrafunctional or higher sugar alcohol derivative. Note that, the sugar alcohol derivative indicates a compound in which a part of a hydroxyl group of sugar alcohol is a salt or a compound in which a part of a hydroxyl group of sugar alcohol reacts with another functional group. Note that, the number average molecular weight in this description is a value measured by gel permeation chromatography (GPC) in the following condition.

[0013] Measurement Device; HLC-8320GPC, manufactured by Tosoh Corporation Column; TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1OOOHXL, manufactured by Tosoh Corporation Detector; RI (a differential refractometer)

Data Processing; Multistation GPC-8020 model II, manufactured by Tosoh Corporation Measurement Condition; a column temperature of 40°C Solvent tetrahydrofuran Flow Rate 0.35 ml/minute Standard; monodisperse polystyrene Sample; 0.2% by mass of a tetrahydrofuran solution in terms of a resin solid content, which is filtered with a microfilter (100 pl)

[0014] Specific examples of the sugar alcohol derivative include an alkylene oxide adduct in which alkylene oxide such as ethylene oxide, propylene oxide, and butylene oxide is added to sugar alcohol such as pentaerythritol, sucrose, xylitol, sorbitol, isomalt, lactitol, maltitol, and mannitol, and a polyalkylene oxide adduct in which polyalkylene oxide such as polyethylene oxide, polypropylene oxide, and polybutylene oxide is added to the sugar alcohol described above.

[0015] It is considered that the cross-linking density of a cured coating film of the adhesive increases, and content resistance is improved, by using the polyol (A). In addition, it is considered that in general polyether polyol is less likely to re-dissolve a printing layer, but the sugar alcohol derivative has a high viscosity compared to general-purpose polyether polyol, and is more excellent in an effect of suppressing the re-dissolution of the printing layer (ink solubility resistance).

[0016] The compound amount of the polyol (A) is 5% by mass or more and 30% by mass or less with respect to the total amount of the polyol (A) and polyester polyol (B) described below. Accordingly, it is possible to obtain the adhesive that is excellent in the content resistance and has excellent coatability and pot life. The compound amount of the polyol (A) is more preferably 10% by mass or more, and even more preferably 25% by mass or less, with respect to the total amount of the polyol (A) and the polyester polyol (B).

[0017] (Polyester Polyol (B)) The polyester polyol (B) is a reaction product between polyhydric alcohol and a polycarboxylic acid. The polyhydric alcohol used in the synthesis of the polyester polyol

(B) is not particularly limited, and a difunctional or trifunctional or higher polyhydric alcohol can be used. Examples of the difunctional alcohol include: aliphatic diol such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3 butanediol, 1,5-pentanediol, 3-methyl 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4 bis(hydroxymethyl) cyclohexane, 2,2,4-trimethyl-1,3-pentanediol, and dimer diol; ether glycol such as polyoxyethylene glycol and polyoxypropylene glycol; modified polyether diol obtained by ring-opening polymerization between aliphatic diol and various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether; lactone-based polyester polyol obtained by a polycondensation reaction between aliphatic diol and various lactones such as lanthanoid and 8-caprolactone; bisphenol such as bisphenol A and bisphenol F; and an alkylene oxide adduct of bisphenol obtained by adding ethylene oxide, propylene oxide, or the like to bisphenol such as bisphenol A and bisphenol F.

[0018] Examples of trifunctional or higher polyol include: aliphatic polyol such as trimethylol ethane, trimethylol propane, glycerin, hexane triol, and pentaerythritol; modified polyether polyol obtained by ring-opening polymerization between aliphatic polyol and various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether; and lactone-based polyester polyol obtained by a polycondensation reaction between aliphatic polyol and various lactones such as -caprolactone.

[0019] Examples of the polycarboxylic acid used in the synthesis of the polyester polyol (B) include: an aliphatic polycarboxylic acid such as a malonic acid, an ethyl malonic acid, a dimethyl malonic acid, a succinic acid, a 2,2-dimethyl succinic acid, a succinic anhydride, an alkenyl succinic anhydride, a glutaric acid, an adipic acid, a pimelic acid, a suberic acid, an azelaic acid, a sebacic acid, a fumaric acid, a maleic acid, a maleic anhydride, an itaconic acid, a dimer acid, and a trimer acid;

[0020] an alkyl esterified product of an aliphatic polycarboxylic acid such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0021] an alicyclic polycarboxylic acid such as 1,1-a cyclopentane dicarboxylic acid, a 1,2 cyclopentane dicarboxylic acid, a 1,3-cyclopentane dicarboxylic acid, a 1,2-cyclohexane dicarboxylic acid, a 1,3-cyclohexane dicarboxylic acid, a 1,4-cyclohexane dicarboxylic acid, a tetrahydrophthalic anhydride, a 4-methyl hexahydrophthalic anhydride, a hexahydrophthalic anhydride, a cyclohexane-1,2,4-tricarboxylic-1,2-anhydride, a himic anhydride, and a chlorendic anhydride;

[0022] an aromatic polycarboxylic acid such as an orthophthalic acid, a terephthalic acid, an isophthalic acid, a phthalic anhydride, a 1,4-naphthalene dicarboxylic acid, a 2,5 naphthalene dicarboxylic acid, a 2,6-naphthalene dicarboxylic acid, a 2,3-naphthalene dicarboxylic anhydride, a naphthalic acid, a trimellitic acid, a trimellitic anhydride, a pyromellitic acid, a pyromellitic anhydride, a biphenyl dicarboxylic acid, a 1,2 bis(phenoxy)ethane-p,p'-dicarboxylic acid, a benzophenone tetracarboxylic acid, a benzophenone tetracarboxylic dianhydride, a 5-sodium sulfoisophthalic acid, a tetrachlorophthalic anhydride, and a tetrabromophthalic anhydride; and

[0023] a methyl esterified product of an aromatic polycarboxylic acid such as a dimethyl terephthalic acid and dimethyl 2,6-naphthalene dicarboxylate, and among them, one type or two or more types can be used in combination.

[0024] By containing the polyester polyol (B) together with the polyol (A), it is possible to obtain the adhesive excellent in the content resistance. In particular, it is preferable to contain the aromatic polycarboxylic acid as the polycarboxylic acid since the content resistance is improved. It is preferable that the compound amount of the aromatic polycarboxylic acid with respect to the polycarboxylic acid is 25% by mass or more and 50% by mass or less. From the viewpoint of the pot life, it is more preferable that the compound amount is 40% by mass or less.

[0025]

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In addition, in general, it is known that there is a tendency that low-molecular weight polyester polyol is likely to re-dissolve the printing layer, but it is preferable that the polyhydric alcohol contains diethylene glycol since the ink solubility resistance is improved without impairing the content resistance. The compound amount of the diethylene glycol with respect to the polyhydric alcohol can be suitably adjusted, and as an example, it is preferable that the compound amount is 50% by mass or more.

[0026] In addition, it is preferable that lactone-added polyester polyol is used as the polyester polyol (B) since the content resistance is improved.

[0027] (Polyol (C)) The polyol composition (X) may contain polyol (C) other than the polyol (A) and the polyester polyol (B). As such polyol (C), the same as the polyhydric alcohol exemplified as the raw material of the polyester polyol (B) can be used. The compound amount of the polyol (C) is not particularly limited, and is preferably within 20% by mass or less with respect to the total amount of the polyol (A), the polyester polyol (B), and the polyol (C).

[0028] The viscosity of the polyol composition (X) is adjusted in a range suitable for a non-solvent lamination method. As an example, the viscosity at 40 to 60°C is adjusted in a range of 100 to 5000 mPas, and more preferably 500 to 3000 mPas. Asanexample,the viscosity of the polyol composition (X) can be adjusted in accordance with the skeleton or the number average molecular weight of the polyester polyol (B), and a plasticizer (E5) described below.

[0029] (Polyisocyanate Composition (Y)) The polyisocyanate composition (Y) contains a polyisocyanate compound (D) having a plurality of isocyanate groups. The polyisocyanate compound (D) is not particularly limited, and examples thereof include aromatic diisocyanate, aromatic aliphatic diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, a biuret, a nurate, an adduct, an allophanate, a modified carbodiimide, and a modified uretdione of such diisocyanates, a urethane prepolymer obtained by allowing such polyisocyanates and polyol to react with each other, and the like, and among them, one can be used alone or a plurality thereof can be used in combination.

[0030] Examples of the aromatic diisocyanate may include 2,2'-diphenyl methane diisocyanate, 2,4'-diphenyl methane diisocyanate, 4,4'-diphenyl methane diisocyanate, polymethylene polyphenyl polyisocyanate (also referred to as polymeric MDI or crude MDI), 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 2,4 tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6 triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4',4"-triphenyl methane triisocyanate, and the like, but the aromatic diisocyanate is not limited thereto.

[0031] The aromatic aliphatic diisocyanate indicates aliphatic isocyanate having one or more aromatic rings in molecules, and examples thereof may include m- or p-xylylene diisocyanate (Alternate Name: XDI), a,a,a',a'-tetramethyl xylylene diisocyanate (Alternate Name: TMXDI), and the like, but the aromatic aliphatic diisocyanate is not limited thereto.

[0032] Examples of the aliphatic diisocyanate may include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (Alternate Name: HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3 butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate, and the like, but the aliphatic diisocyanate is not limited thereto.

[0033] Examples of the alicyclic diisocyanate may include 3-isocyanate methyl-3,5,5 trimethyl cyclohexyl isocyanate, isophorone diisocyanate (Alternate Name: 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 bis(cyclohexyl isocyanate), 1,4-bis(isocyanate methyl) cyclohexane, and the like, but the alicyclic diisocyanate is not limited thereto.

[0034] As the polyol used in the synthesis of the urethane prepolymer, the same as that exemplified as the raw material of the polyester polyol (B) can be used. From the viewpoint that it is possible to increase an adhesive strength while decreasing the viscosity of the adhesive, it is preferable to use at least one type of polyalkylene glycol and polyester polyol.

[0035]

It is preferable that the polyalkylene glycol has a number average molecular weight in a range of 200 to 6,000. It is preferable that the polyester polyol is obtained by allowing polyalkylene glycol and an aliphatic polycarboxylic acid having 2 to 30 carbon atoms to react with each other. In addition, in the polyester polyol, as an alcohol component of a raw material, trifunctional or higher alcohol such as glycerin, trimethylol propane, and pentaerythritol may be used at a ratio of 10% by mass or less in the polyol component.

[0036] As a flexible packaging base material, polyisocyanate obtained by allowing aromatic polyisocyanate and polyalkylene glycol having a number average molecular weight in a range of 200 to 6,000 to react with each other, and polyisocyanate obtained by allowing aromatic polyisocyanate and polyester polyol having a number average molecular weight in a range of 200 to 3,000 to react with each other are preferable from the viewpoint that appropriate flexibility can be imparted to a cured product. It is preferable that an isocyanate content ratio according to a titration method (using di-n-butyl amine) is 5 to 20% by mass since an appropriate resin viscosity is obtained and excellent coating properties are obtained.

[0037] On the other hand, as a hard base material, polyisocyanate obtained by allowing aromatic polyisocyanate and polyester polyol having a number average molecular weight in a range of 200 to 3000 to react with each other, and polyisocyanate obtained by allowing aromatic polyisocyanate and a mixture of polyester polyol having a number average molecular weight in a range of 200 to 3,000 and polyalkylene glycol having a number average molecular weight in a range of 200 to 6,000 to react with each other are preferable from the viewpoint of excellent adhesive strength. It is preferable that an isocyanate content ratio according to a usual method (using di-n-butyl amine) is 5 to 20% by mass since an appropriate resin viscosity is obtained and excellent coating properties are obtained.

[0038] In a case where the polyisocyanate compound (D) is a urethane prepolymer, it is preferable that an equivalence ratio [NCO]/[OH] of an isocyanate group and a hydroxyl group provided to the reaction is in a range of 1.5 to 5.0 since the viscosity of the adhesive in an appropriate range and excellent coating properties are obtained.

[0039] The viscosity of the polyisocyanate composition (Y) is adjusted in a range suitable for a non-solvent lamination method. As an example, the viscosity at 40°C is adjusted in a

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range of 500 to 5000 mPas, and more preferably in a range of 500 to 3000 mPas. As an example, the viscosity of the polyisocyanate composition (Y) can be adjusted in accordance with the compound amount of the urethane prepolymer, or the compound amount of a low molecular-weight isocyanate compound.

[0040] (Other Components (E) of Adhesive) The adhesive of the invention may contain components other than the components described above. The other components (E) may be contained in any one or both of the polyol composition (X) and the polyisocyanate composition (Y), or may be prepared separately and mixed with the polyol composition (X) and the polyisocyanate composition (Y) immediately before applying the adhesive. Hereinafter, each of the components will be described.

[0041] (Catalyst (El)) As a catalyst (El), a metal-based catalyst, an amine-based catalyst, an aliphatic cyclic amide compound, and the like are exemplified.

[0042] Examples of the metal-based catalyst (El) include a metal complex-based catalyst, an inorganic metal-based catalyst, and an organic metal-based catalyst. As the metal complex-based catalyst, an acetyl acetonate of a metal selected from the group consisting of iron (Fe), manganese (Mn), copper (Cu), zirconium (Zr), thorium (Th), titanium (Ti), aluminum (Al), and cobalt (Co), for example, iron acetyl acetonate, manganese acetyl acetonate, copper acetyl acetonate, zirconia acetyl acetonate, and the like are exemplified.

[0043] Examples of the inorganic metal-based catalyst include an inorganic metal-based catalyst selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, and the like.

[0044] Examples of the organic metal-based catalyst include an organic zinc compound such as zinc octylate, zinc neodecanoate, and zinc naphthenate, an organic tin compound such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyl tin diacetate, dibutyl tin dilaurate, dioctyl tin dilaurate, dibutyl tin oxide, and dibutyl tin dichloride, an organic nickel compound such as nickel octylate and nickel naphthenate, an organic cobalt compound such as cobalt octylate and cobalt naphthenate, an organic bismuth compound such as bismuth octylate, bismuth neodecanoate, and bismuth naphthenate, and a titanium-based compound such as tetraisopropyl oxytitanate, dibutyl titanium dichloride, tetrabutyl titanate, butoxy titanium trichloride, and a titanium chelate complex including at least one type of aliphatic diketone, aromatic diketone, and alcohol having 2 to 10 carbon atoms as a ligand.

[0045] Examples of the amine-based catalyst include triethylene diamine, 2-methyl triethylene diamine, quinuclidine, 2-methyl quinuclidine, N,N,N',N'-tetramethyl ethylene diamine, N,N,N',N'-tetramethyl propylene diamine, N,N,N',N",N"-pentamethyl diethylene triamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl) ethylene diamine, N,N,N',N",N" pentamethyl dipropylene triamine, N,N,N',N'-tetramethyl hexamethylene diamine, bis(2 dimethyl aminoethyl) ether, dimethyl ethanol amine, dimethyl isopropanol amine, dimethyl aminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl) ethylene diamine, N,N-dimethyl-N' (2-hydroxyethyl) propane diamine, bis(dimethyl aminopropyl) amine, bis(dimethyl aminopropyl) isopropanol amine, 3-quinuclidinol, N,N,N',N'-tetramethyl guanidine, 1,3,5 tris(N,N-dimethyl aminopropyl) hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N methyl-N'-(2-dimethyl aminoethyl) piperazine, N,N'-dimethyl piperazine, dimethyl cyclohexyl amine, N-methyl morpholine, N-ethyl morpholine, 1-methyl imidazole, 1,2 dimethyl imidazole, 1-isobutyl-2-methyl imidazole, 1-dimethyl aminopropyl imidazole, N,N dimethyl hexanol amine, N-methyl-N'-(2-hydroxyethyl) piperazine, 1-(2-hydroxyethyl) imidazole, 1-(2-hydroxypropyl) imidazole, 1-(2-hydroxyethyl)-2-methyl imidazole, and 1-(2 hydroxypropyl)-2-methyl imidazole.

[0046] Examples of the aliphatic cyclic amide compound include S-valerolactam,CS caprolactam, co-enantholactam, T-capryllactam, and p-propiolactam. Among them, thec caprolactam is effective from the viewpoint of curing acceleration.

[0047] (Acid Anhydride (E2)) Examples of an acid anhydride (E2) include a cyclic aliphatic anhydride, an aromatic anhydride, and unsaturated carboxylic anhydride, and among them, one type or two or more types can be used in combination. More specifically, for example, a phthalic anhydride, a trimellitic anhydride, a pyromellitic anhydride, a benzophenone tetracarboxylic anhydride, a dodecenyl succinic anhydride, a polyadipic anhydride, a polyazelaic anhydride, a polysebacic anhydride, a poly(ethyl octadecanedioic) anhydride, a poly(phenyl hexadecanedioic) anhydride, a tetrahydrophthalic anhydride, a methyl tetrahydrophthalic anhydride, a methyl hexahydrophthalic anhydride, a hexahydrophthalic anhydride, a methyl himic anhydride, a trialkyl tetrahydrophthalic anhydride, a methyl cyclohexene dicarboxylic anhydride, a methyl cyclohexene tetracarboxylic anhydride, an ethylene glycol bistrimellitate dianhydride, a het anhydride, a nadic anhydride, a methyl nadic anhydride, a 5-(2,5 dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, a 3,4 dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, a 1-methyl-dicarboxy 1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, and the like are included in the examples of the acid anhydride (E2).

[0048] In addition, as the acid anhydride (E2), an acid anhydride obtained by modifying the compound described above with glycol may be used. Examples of the glycol that can be used in the 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. Further, among them, copolymerized polyether glycol of two or more types of glycols and/or polyether glycols can also be used.

[0049] (Coupling Agent (E3)) Examples of a coupling agent (E3) include a silane coupling agent, a titanate-based coupling agent, and an aluminum-based coupling agent.

[0050] Examples of the silane coupling agent include aminosilane such asy-aminopropyl triethoxy silane, y-aminopropyl trimethoxy silane, N-(aminoethyl)-y-aminopropyl trimethoxy silane, N-(aminoethyl)--aminopropyl trimethyl dimethoxy silane, and N-phenyl

y-aminopropyl trimethoxy silane; epoxy silane such as p-(3,4-epoxy cyclohexyl) ethyl trimethoxy silane, 7-glycidoxypropyl trimethoxy silane, andy-glycidoxypropyl triethoxy silane; vinyl silane such as vinyl tris(p-methoxyethoxy) silane, vinyl triethoxy silane, vinyl trimethoxy silane, and y-methacryloxypropyl trimethoxy silane; hexamethyl disilazane, and y mercaptopropyl trimethoxy silane.

[0051] Examples of the titanate-based coupling agent include tetraisopropoxy titanium, tetra-n-butoxy titanium, butyl titanate dimer, tetrastearyl titanate, titanium acetyl acetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxy titanium.

[0052] Examples of the aluminum-based coupling agent include acetoalkoxy aluminum diisopropylate.

[0053] (Pigment (E4)) A pigment (E4) is not particularly limited, and examples thereof include an extender pigment, an organic pigment or an inorganic pigment such as a white pigment, a black pigment, a gray pigment, a red pigment, a brown pigment, a green pigment, a blue pigment, a metal powder pigment, a light emitting pigment, and a pearl pigment, and further include a plastic pigment, which are described in Handbook of Painting Material, published in 1970 (edited by Japan Paint Manufacturers Association).

[0054] Examples of the extender pigment include settleable barium sulfate, a powder, settleable calcium carbonate, calcium bicarbonate, white marble, white alumina, silica, fine hydrous silica powder (white carbon), ultrafine anhydrous silica powder (AEROSIL), silica sand, talc, settleable magnesium carbonate, bentonite, clay, kaolinite, ocher, and the like.

[0055] Specific examples of the organic pigment include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, and Laked 4R; a soluble azo pigment such as Laked C, Carmine 6B, and Bordeaux 10; various (copper) phtalocyanine-based pigments such as Phtalocyanine Blue and Phtalocyanine Green; various chlorine dyeing lakes such as Rhodamine Lake and Methyl Violet Lake; various mordant dye-based pigments such as Quinoline Lake and Fast Sky Blue; various vat dye-based pigments such as an anthraquinone based pigment, a thioindigo-based pigment, and a perinone-based pigment; various quinacridone-based pigments such as Shinkasha Red B; various dioxazine-based pigments such as Dioxazine Violet; various condensed azo pigments such as Cromophtal; and Aniline Black.

[0056] Examples of the inorganic pigment include various chromates such as Lead Yellow, zinc chromate, and Molybdate Orange; various ferrocyanic compounds such as Prussian Blue; various metal oxides such as titanium oxide, zinc oxide, Mapico Yellow, iron oxide, Bengala, Chromium Oxide Green, and zirconium oxide; various sulfides or selenides such as Cadmium

Yellow, Cadmium Red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and Ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as Cobalt Violet and Manganese Violet; various metal powder pigments such as an aluminum powder, a gold powder, a silver powder, a copper powder, a bronze powder, and a brass powder; a flake pigment and a mica/flake pigment of such metals; a metallic pigment or a pearl pigment such as a mica/flake pigment in the form of covering a metal oxide, mica-shaped iron oxide pigment; graphite, and carbon black.

[0057] Examples of the plastic pigment include "GRANDOLL PP-1000", and "PP-2000S", which are manufactured by DIC Corporation.

[0058] The pigment (E4) to be used may be suitably selected in accordance with the purpose, and for example, from the viewpoint of excellent durability, weather resistance, and designability, it is preferable to use an inorganic oxide such as titanium oxide and zinc oxide as the white pigment, and it is preferable to use carbon black as the black pigment.

[0059] As an example, the compound amount of the pigment (E4) is 1 to 400 parts by mass with respect to 100 parts by mass of the total amount of the solid contents of the polyol composition (X) and the polyisocyanate composition (Y), and more preferably 10 to 300 parts by mass, from the viewpoint of more excellent adhesiveness and blocking resistance.

[0060] (Plasticizer (E5)) Examples of a plasticizer include a phthalic acid-based plasticizer, a fatty acid based plasticizer, an aromatic polycarboxylic acid-based plasticizer, a phosphoric acid-based plasticizer, a polyol-based plasticizer, an epoxy-based plasticizer, a polyester-based plasticizer, and a carbonate-based plasticizer.

[0061] Examples of the phthalic acid-based plasticizer include a phthalic acid ester-based plasticizer such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethyl hexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, octyl decyl phthalate, dimethyl isophthalate, di-(2-ethyl hexyl) isophthalate, and diisooctyl isophthalate, and, a tetrahydrophthalic acid ester-based plasticizer such as di-(2-ethyl hexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

[0062] Examples of the fatty acid-based plasticizer include an adipic acid-based plasticizer such as di-n-butyl adipate, di-(2-ethyl hexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diglycol adipate, an azelaic acid-based plasticizer such as di-n-hexyl azelate, di-(2-ethyl hexyl) azelate, and diisooctyl azelate, for example, a sebacic acid-based plasticizer such as di-n-butyl sebacate, di-(2-ethyl hexyl) sebacate, and diisononyl sebacate, for example, a maleic acid-based plasticizer such as dimethyl malate, diethyl malate, di-n-butyl malate, and di-(2-ethyl hexyl) malate, a fumaric acid-based plasticizer such as di-n butyl furmarate and di-(2-ethyl hexyl) fumarate, for example, an itaconic acid-based plasticizer such as monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, di-(2-ethyl hexyl) itaconate, for example, a stearic acid-based plasticizer such as n-butyl stearate, glycerin monostearate, and diethylene glycol distearate, an oleic acid based plasticizer such as butyl oleate, glyceryl monooleate, and diethylene glycol monooleate, for example, a citric acid-based plasticizer such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, and acetyl tri-(2-ethyl hexyl) citrate, a ricinoleic acid based plasticizer such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, glyceryl monoricinoleate, and diethylene glycol monoricinoleate, and other fatty acid-based plasticizers such as diethylene glycol monolaurate, diethylene glycol dipelargonate, and pentaerythritol fatty acid ester.

[0063] Examples of the aromatic polycarboxylic acid-based plasticizer include a trimellitic acid-based plasticizer such as tri-n-hexyl trimellitate, tri-(2-ethyl hexyl) trimellitate, tri-n octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, and triisodecyl trimellitate, and a pyromellitic acid-based plasticizer such as tetra-(2-ethyl hexyl) pyromellitate and tetra-n-octyl pyromellitate.

[0064] Examples of the phosphoric acid-based plasticizer include triethyl phosphate, tributyl phosphate, tri-(2-ethyl hexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, cresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate, and tris(isopropyl phenyl) phosphate.

[0065] Examples of the polyol-based plasticizer include a glycol-based plasticizer such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethyl butyrate), triethylene glycol di-(2-ethyl hexoate), and dibutyl methylene bisthioglycolate, and a glycerin-based plasticizer such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.

[0066] Examples of the epoxy-based plasticizer include epoxidized soybean oil, epoxy butyl stearate, epoxy di-2-ethyl hexyl hexahydrophthalate, epoxy diisodecyl hexahydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.

[0067] Examples of the polyester-based plasticizer include adipic acid-based polyester, sebacic acid-based polyester, and phthalic acid-based polyester.

[0068] Examples of the carbonate-based plasticizer include propylene carbonate, and ethylene carbonate.

[0069] In addition, examples of the plasticizer further include partially hydrogenated terphenyl, an adhesive plasticizer, and a polymerizable plasticizer such as diallyl phthalate, and an acrylic monomer or oligomer. One of the plasticizers can be used alone, or two or more types thereof can be used together.

[0070] (Phosphoric Acid Compound (E6)) Examples of a phosphoric acid compound (E6) include a phosphoric acid, a pyrophosphoric acid, a triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethyl hexyl acid phosphate, bis(2-ethyl hexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphoric acid.

[0071] (Compound (E7))

From the viewpoint of excellent adhesion to a metal base material, it is preferable to contain a compound (E7), which is at least one type selected from the group consisting of a 2,2-dimethylol acetic acid, a 2,2-dimethylol propionic acid, a 2,2-dimethylol butanoic acid, and a 2,2-dimethylol pentanoic acid. As the compound (E7), at least one type of the 2,2 dimethylol propionic acid and the 2,2-dimethylol butanoic acid is more preferable. The compound amount of the compound (E7) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and is preferably 10% by mass or less, and more preferably 2.5% by mass or less, with respect to the polyol composition (X).

[0072] (Form of Adhesive) The adhesive of the invention is used in a solvent-free form. Note that, in this description, a "solvent-free" adhesive indicates an adhesive in the form where the polyol composition (X) and the polyisocyanate composition (Y) do not substantially contain an organic solvent with high solubility, such as esters such as ethyl acetate, butyl acetate, and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide and dimethyl sulfonamide, and in particular, the ethyl acetate or the methyl ethyl ketone, and thus, the adhesive is used in a method for pasting the base material to another base material without a step of volatilizing the solvent by heating in an oven or the like after coating the base material with the adhesive, a so-called non-solvent lamination method. In a case where the constituent of the polyol composition (X) and the polyisocyanate composition (Y), or an organic solvent used as a reaction medium when producing the raw materials is not completely removed, and thus, a small amount of organic solvent remains in the polyol composition (X) and the polyisocyanate composition (Y), it is understood that the organic solvent is not substantially contained. In addition, in a case where the polyol composition (X) contains low-molecular-weight alcohol, the low-molecular weight alcohol reacts with the polyisocyanate composition (Y) to be a part of a coating film, and thus, is not required to be volatilized after coating. Accordingly, such a form is also treated as the solvent-free adhesive, and the low-molecular-weight alcohol is not regarded as an organic solvent.

[0073] It is preferable to use the adhesive of the invention by compounding the polyisocyanate composition (Y) and the polyol composition (X) such that a ratio [NCO]/[OH] of a molar number [NCO] of an isocyanate group in the polyisocyanate composition (Y) to a molar number [OH] of a hydroxyl group in the polyol composition (X) is 1.0 to 3.0.

[0074] <Laminate> A laminate of the invention is obtained by pasting a plurality of base materials (films or paper sheets) by using the adhesive of the invention, in accordance with a non solvent lamination method. The film to be used is not particularly limited, and a film according to the usage can be suitably selected. Examples of a film for food packaging include a polyolefin film such as a polyethylene terephthalate (PET) film, a polystyrene film, a polyamide film, a polyacrylonitrile film, a polyethylene film (a low-density polyethylene film (LLDPE), and a high-density polyethylene film (HDPE)), and a polypropylene film (a cast polypropylene film (CPP), and a biaxially oriented polypropylene film (OPP)), a polyvinyl alcohol film, and an ethylene-vinyl alcohol copolymer film.

[0075] The film may be subjected to an orientation treatment. As an orientation treatment method, it is common to melt and extrude a resin into the shape of a sheet by an extrusion film formation method or the like, and then, to perform simultaneous biaxial orientation or sequential biaxial orientation. In addition, in the case of the sequential biaxial orientation, it is common to first perform a longitudinal orientation treatment, and then, perform a lateral orientation. Specifically, a method for combining the longitudinal orientation using a rate difference between rolls and the lateral orientation using a tenter is generally used.

[0076] The surface of the film may be subjected to various surface treatments such as a flame treatment and a corona discharge treatment, as necessary, such that an adhesive layer without a defect such as film cutting or cissing is formed.

[0077] Alternatively, a film on which a vapor deposition layer of a metal such as aluminum and a metal oxide such as silica and alumina is laminated, and a barrier film including a gas barrier layer such as polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and vinylidene chloride may be used. By using such a film, it is possible to obtain the laminate having barrier properties with respect to water vapor, oxygen, alcohol, inert gas, a volatile organic substance (fragrance), and the like.

[0078] The paper is not particularly limited, and a known paper base material can be used. Specifically, the paper is produced in a known paper machine by using a natural fiber for papermaking such as wood pulp, but the papermaking condition is not particularly defined. Examples of the natural fiber for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, Sisal hemp pulp, and flax pulp, and pulp obtained by performing chemical modification with respect to the pulp described above. As the type of pulp, chemical pulp obtained by a sulfate digestion method, an acidic/neutral/alkaline sulfite digestion method, a sodium carbonate salt digestion method, and the like, ground pulp, chemi-ground pulp, thermo-mechanical pulp, and the like can be used. In addition, various commercially available high-quality paper sheets or coated paper sheets, lining paper sheets, impregnated paper sheets, cardboard sheets, paperboard sheets, and the like can also be used.

[0079] The laminate obtained by using the adhesive of the invention has excellent resistance to content such as a shampoo, a conditioner, or a softener, containing a component that reaches the adhesive layer through a sealant film such as a CPP film or an LLDPE film, and causes the degradation of the adhesive layer and a decrease in the adhesive strength. Accordingly, it is preferable to use the adhesive of the invention as an adhesive for pasting the base material and the sealant film.

[0080] Examples of a specific configuration include Nyl Film/Transparent Vapor Deposition PET Film/Adhesive Layer according to Invention/Sealant Film, PET Film/Transparent Vapor Deposition PET Film/Adhesive Layer according to Invention/Sealant Film, PET Film/Aluminum Foil/Adhesive Layer according to Invention/Sealant Film, PET Film/Aluminum Foil/Adhesive Layer according to Invention/PET Film/Sealant Film, PET Film/Aluminum Vapor Deposition PET Film/Adhesive Layer according to Invention/Sealant Film. As other configurations, a laminate having a configuration of Nyl Film/Aluminum Vapor Deposition PET Film/Adhesive Layer according to Invention/Sealant Film is also preferable since the laminate is excellent in the content resistance. In such laminates, an adhesive layer other than the adhesive layer according to the invention may be pasted by using a general-purpose adhesive, or may be pasted by using the adhesive of the invention. Note that, in general, in the laminate for a packaging material, the printing layer described

2U

below is provided at a suitable position, but it is not described in the above example. In a case where more strength such as puncture resistance is required, a transparent vapor deposition Nyl film may be used, instead of the aluminum vapor deposition PET film and the transparent vapor deposition PET film.

[0081] In the laminate of the invention, a printing layer may be provided between the adhesive layer and the base material (in general, the base material to be the outermost layer with respect to the content). The printing layer is formed by a general printing method, which has been used in printing to a film using various printing inks such as a gravure ink, a flexographic ink, an offset ink, a stencil ink, and an inkjet ink, in the related art.

[0082] The adhesive of the invention, which is heated in advance to approximately 40°C to 100°C, is applied to the film or the paper material to be the base material by using a roll such as a gravure roll, and then, the other base material is immediately pasted to obtain the laminate of the invention. It is preferable to perform an aging treatment after laminating. It is preferable that an aging temperature is a room temperature to 70°C, and an aging time is 6 to 240 hours.

[0083] The applied amount of the adhesive is suitably adjusted, and as an example, is 1 g/m2 or more and 5 g/m 2 or less. In a case where the applied amount of the adhesive increases, a winding deviation may easily occur, and from the viewpoint of workability, the applied amount is preferably 1 g/m2 or more and 3 g/m2 or less.

[0084] The laminate of the invention is obtained by pasting two base materials with the adhesive of the invention, but as necessary, may include another base material. As a method for laminating another base material, another base material may be laminated by a known method, for example, a dry lamination method, a non-solvent lamination method, a heat lamination method, a heat seal method, an extrusion lamination method, and the like. In this case, the adhesive to be used may be or may not be the adhesive of the invention. As another base material, the same base material as described above can be used.

[0085] <Packaging Material> A packaging material of the invention is obtained by molding the laminate described above into the shape of a bag, and heat-sealing the laminate into the form of a packaging material. There are various packaging materials such as a three-side sealing bag, a four-side sealing bag, a gusset packaging bag, a pillow packaging bag, a gable-top bottomed container, Tetra Classic, a Bruck type, a tube container, a paper cup, and a lid material. In addition, easy-opening processing or resealing means may be suitably provided in the packaging material of the invention.

[0086] The packaging material of the invention can be mainly used industrially as a packaging material filled with food, a detergent, and a chemical. As a specific usage, examples of the detergent and the chemical include a liquid laundry detergent, a liquid kitchen detergent, a liquid bath detergent, liquid bath soap, a liquid shampoo, a liquid conditioner, a pharmaceutical tablet, and the like. In addition, the packaging material can also be used in a secondary packaging material for packaging the container described above.

EXAMPLES

[0087] Hereinafter, the invention will be described in more detail by specific synthesis examples and examples, and the invention is not limited to the examples. Note that, in the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0088] <Polyol Composition (X)> (Synthesis of Polyester Polyol (B-1)) A flask provided with a stirrer, a thermometer, a nitrogen gas introduction tube, a rectification tube, a water separator, and the like was charged with 13.3 parts of ethylene glycol, 28.5 parts of diethylene glycol, and 3.0 parts of trimethylol propane in a reaction container, was stirred while nitrogen gas was introduced, and was heated to100°C. 35.7 parts of an adipic acid and 19.1 parts of an isophthalic acid were added at 100 to110°C, were gradually heated such that the upper temperature of the rectification tube was not higher than 100°C, and thus, the internal temperature was retained at 240°C, and stirring was performed foreight hours to obtain polyester polyol (B)-1.

[0089] (Synthesis of Polyester Polyols (B-2) to (B-6))

Polyester polyols (B-2) to (B-6) were obtained as with the polyester polyol (B-1), except that polyhydric alcohol, a polycarboxylic acid, and a reaction time used in the synthesis were changed to those as shown in Table 1. Note that, in the table, "Compound Amount of Aromatic Carboxylic Acid" indicates the compound amount (% by mass) of an aromatic polycarboxylic acid with respect to the polycarboxylic acid used in the synthesis of the polyester polyol (B), and "Compound Amount of DEG" indicates the compound amount (% by mass) of diethylene glycol with respect to the polyhydric alcohol used in the synthesis of the polyester polyol (B). In addition, the details of the compounds shown in the table are as follows. AA: an adipic acid IPA: an isophthalic acid DEG: diethylene glycol EG: ethylene glycol PPG400: SANNIX PK-400GD (manufactured by Sanyo Chemical Industries, Ltd.) TMP: trimethylol propane

[0090]

[Table 1]

B-1 B-2 B-3 B-4 B-5 B-6

Polycarboxylic AA 35.7 39.1 32.0 39.3 31.9 45.9 Acid IPA 19.1 14.8 24.3 14.9 12.1 7.8 EG 13.3 12.9 13.8 5.6 10.8 14.9

Polyhydric DEG 28.5 26.9 29.5 37.8 11.3 31.1 Alcohol PPG400 31.1 TMP 3.0 5.9 2.0 2.4 Reaction Time (hr) 8 15 8 25 14 13 Compound Amount of 34.9 27.4 43.2 27.5 27.5 14.5 Aromatic Carboxylic Acid Compound Amount of DEG 63.6 58.9 68.1 83.3 20.3 67.6

[0091] (Preparation of Polyol Composition (X)) Polyol (A), the polyester polyol (B), and an additive (a dimethylol propionic acid) were compounded in accordance with compounds shown in Tables 2 to 4 to obtain a polyol composition (X). Note that, the polyol (A) used in the preparation of the polyol composition (X) is as follows.

[0092]

Polyol (A-1): SANNIX HD-402 (pentaerythritol-based polyether polyol, the number of functional groups of 4, and a number average molecular weight of 600, manufactured by Sanyo Chemical Industries, Ltd.) Polyol (A-2): SANNIX HS-209 (sucrose-based polyether polyol, the number of functional groups of 6, and a number average molecular weight of 600, manufactured by Sanyo Chemical Industries, Ltd.) Polyol (A-3): SANNIX SP-750 (polyoxypropylene sorbitol ether, hexafunctional, and a number average molecular weight of 700, manufactured by Sanyo Chemical Industries, Ltd.) Polyol (A-4): EXCENOL 385SO (a propylene oxide adduct of sorbitol, hexafunctional, and a number average molecular weight of 500, manufactured by AGC Inc.) Polyol (A'-1): SANNIX PP-600 (polypropylenediol, difunctional, and a number average molecular weight of 600, manufactured by Sanyo Chemical Industries, Ltd.) Polyol (A'-2): SANNIX GP-600 (polyoxypropylene triol, trifunctional, and a number average molecular weight of 600, manufactured by Sanyo Chemical Industries, Ltd.)

[0093] <Polyisocyanate Composition (Y)> (Synthesis of Polyisocyanate Composition (Y-1)) A flask provided with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 36 parts of 4,4'-diphenyl methane diisocyanate and 19 parts of 2,4'-diphenyl methane diisocyanate, and was heated to 60°C while stirring under an atmosphere of nitrogen gas. 11 parts of polypropylene glycol with a number average molecular weight of 400, 22 parts of polypropylene glycol with a number average molecular weight of 1000, and 11 parts of polypropylene glycol with a number average molecular weight of 2000 were dropped several times, and were stirred for five to six hours to complete a urethanization reaction. A polyisocyanate composition (Y-1) with an NCO group content ratio of 13.5% and a viscosity of 1500 mPa-s was obtained.

[0094] (Synthesis of Polyisocyanate Composition (Y-2)) A polyester reaction container provided with a stirrer, a thermometer, a nitrogen gas introduction tube, a rectification tube, and a water separator was charged with 60.7 parts of an adipic acid, 28.2 parts of ethylene glycol, and 11.1 parts of diethylene glycol, and was gradually heated such that the upper temperature of the rectification tube was not higher than

100°C, and thus, the internal temperature was retained at 220°C. When an acid value was 2.0 mgKOH/g or less, an esterification reaction was completed, and thus, intermediate polyester polyol was obtained.

[0095] A flask provided with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 30 parts of 4,4'-diphenyl methane diisocyanate and 30 parts of 2,4'-diphenyl methane diisocyanate, and was heated to 60°C while stirring under an atmosphere of nitrogen gas. 40 parts of the intermediate polyester polyol synthesized as described above was dropped several times, and was stirred for five to six hours to complete a urethanization reaction. Apolyisocyanate composition (Y-2) with an NCO group content ratio of 14.0% and a viscosity of 3000 mPa-s was obtained.

[0096] (Synthesis of Polyisocyanate Composition (Y-3)) A flask provided with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 55 parts of 4,4'-diphenyl methane diisocyanate, and was heated to 60°C while stirring under an atmosphere of nitrogen gas. 11 parts of polypropylene glycol with a number average molecular weight of 400, 22 parts of polypropylene glycol with a number average molecular weight of 1000, and 11 parts of polypropylene glycol with a number average molecular weight of 2000 were dropped several times, and were stirred for five to six hours to complete a urethanization reaction. A polyisocyanate composition (Y-3) with an NCO group content ratio of 13.6% and a viscosity of 2000 mPa-s was obtained.

[0097] <Preparation of Adhesive> The polyol composition (X) and the polyisocyanate composition (Y) heated to 40°C were mixed at the compound shown in Tables 2 to 4, and thus, solvent-free adhesives of Examples and Comparative Examples were obtained.

a)

CO Cl

a) - Cl

CO Cl

a)

CO Cl

a) ~

CO

a)

CO Cl

Cl a) 00

Cl

00 CO 6 Cl

Cl ~

Cl ~ ~ o o o ,~ r.O Ct Ct Cl C~ - - - - - - 0 0 0 0 0 0 0 0 0 a) ~. ~, ~. ~ ~ _ _ ~ 0 0 0 ~ ~0 0 0~ a) a) a) C.) - a) a) a) a) 0 _

CO CO CO C.) C.) C.) 0 0 0 - Ct Ct Ct

~- ~- ~-

0) 0 0 00 0 ~ 0 0 o Co _ Cl

0) o 0 00 0 9 0 CO _ 0

Cl 0) 0 00 0 00 ~~o9 CO

0) 00 00 0 0

0

0) Cl 000 0 00 0 Cl CO

0) 0 00 o 9 00 0 CO Cl

00 0) 0 0 00 ~ 9 00 0 00 CO Cl

Cl

Cl ~ ~ ~ o o o

Cl ~ - - - - - - 0 0 0 0 0 0 0 0 0 0) ~. ~. ~. ~ ~ E EQ 0 0 0 ~

-0)0)0)0) ~- ~- ~- ~- ~ CO CO CO C.) C.) C.) 0 0 0 C/) C.') - ~.) .~ .~ .~

~- ~- ~- c~Cl

0.)

~

0.)~. '~

~ 0.)

0.) ~ ~ 0.) 0

0

Cl

ii~ Cl

Cl

ii Cl

ii Cl ~ Cl

0 0 0

~ CN CN ~ '-' rt Ct Ct CC Cl - - ~-~0 0 0

0 ~

~8 000 - 0 0 0 Ct Ct Ct .~ .~ .~

[0101] <Evaluation> (Curing Rate) The adhesive was applied to a biaxially oriented nylon film ("EMBLEM", manufactured by UNITIKA LTD., a film thickness of 15 pm) at an applied amount of 1.8 g/m 2 by using a test laminator manufactured by TESTER SANGYO CO., LTD., and then, the biaxially oriented nylon film and a low-density linear polyethylene film ("TUX-HC", manufactured by Mitsui Chemicals Tohcello, Inc., a film thickness of 60 tm) were pasted and aged at 40°C for 6 hours to obtain a laminate. The polyethylene films of the laminate were set to face each other, and heat seal was performed in the condition of a pressure of 0.1 MPa/cm 2, a temperature of 180°C, and time of 1 second. A heat seal strength between the polyethylene films was measured at 300 mm/min, and was evaluated in accordance with the following criteria, and the results are collectively shown in Tables 5 to 7. A: 40 N/15 mm or more B: 20 N/15 mm or more and less than 40 N/15 mm C: less than 20 N/15 mm

[0102] (Pot Life) The polyol composition (X) and the polyisocyanate composition (Y) were mixed, and then, the viscosity of the adhesive after being left to stand at 40°C for 30 minutes was measured, and was evaluated in accordance with the following criteria, and the results are collectively shown in Tables 5 to 7. A: less than 3000 mPa-s B: 3000 mPa-s or more and less than 5000 mPa-s C: 5000 mPa-s or more

[0103] (Ink Solubility Resistance) A urethane-based laminating ink (Finart R794 White G3; manufactured by DIC Corporation) was adjusted to 15 seconds (25°C) with Zahn cup #3 manufactured by Rigo, Co. Ltd., was printed on a corona-treated polyethylene terephthalate (PET) film (TOYOBO ESTER Film E5102#12) by a gravure printer provided with a gravure engraving having an engraving depth of 43 tm, and was dried or cured by passing through an oven at 70°C, and thus, a printing layer was formed on the PET film.

[0104] One gram of the adhesive obtained by compounding the polyol composition (X) and the polyisocyanate composition (Y) was dropped onto a printed matter, and was left to stand in an oven at 50°C for three minutes, and then, the dropped adhesive portion was subjected to a rubbing test with a black cotton swab. A transfer rate of a white ink to the black cotton swab from the printed matter was evaluated, and the results are collectively shown in Tables 5 to 7. A: 0 to less than 10% B: 10 to less than 50% C: 50% to 100%

[0105] (Content Resistance) 2.0 g/m 2 of the adhesive was applied to a biaxially oriented nylon film ("EMBLEM", manufactured by UNITIKA LTD., a film thickness of 15 pm) by using a test laminator (manufactured by TESTER SANGYO CO., LTD.), and the biaxially oriented nylon film and an aluminum vapor deposition surface of an aluminum vapor deposition PET film (1310, manufactured by Toray Advanced Film Co., Ltd.) were pasted and aged at 40°C for three days. Next, 2.0 g/m2 of the adhesive was applied to a PET film surface of the aluminum vapor deposition PET film by a test laminator (manufactured by TESTER SANGYO CO., LTD.), and the PET film surface and a low-density linear polyethylene film ("TUX-HC", manufactured by Mitsui Chemicals Tohcello, Inc., a film thickness of 60 pm) were pasted and aged at 40°C for three days to obtain a laminate of ONy/VMPET/LLDPE.

[0106] A pouch having a size of 120 mm x 120 mm was prepared by using the obtained laminate, was charged with 70 g of a shampoo (Pantene, manufactured by P&G) as content, and then, was sealed by heat seal. Such a pouch was subjected to an accelerated test at 60°C for three weeks, and then, an adhesive strength between the VMPET/LLDPE films was measured, and was evaluated in accordance with the following criteria, and the results are collectively shown in Tables 5 to 7. A: the VMPET film fractures or the adhesive strength is 4 N/15 mm or more B: 3 N/15 mm or more and less than 4 N/15 mm C: less than 3 N/15 mm a) ~ 00 .~a) a) ~ ~CO CO CO a) ~ a)

C0

a) C-) C.) a)

CO a) ~ a)

CO~

CNI a) ~CO a)

CO CO a) ~ a) CO~ C-) < C-)

a)

a) CO CO -a)

CO~

~ C-) <

a) a) a) ECO a) CO CO~

Cl a) a) -a)

CO~ CO CO

00a) CO~ a) a) -

CO CO

a) a) a) C) C) a) C) CO a) ~- C) a) C) C) ~- a) ~ -CO CO a) a) ~ CO ~ - a) a) 0 - 2 a) C-)

0 C.) 0 ~ C-) C-) ~

Claims (6)

1. [Claim 1] A solvent-free adhesive, comprising: a polyol composition (X); and a polyisocyanate composition (Y), wherein the polyol composition (X) has a number average molecular weight of 450 or more and 1000 or less, and contains polyol (A), which is a tetrafunctional or higher sugar alcohol derivative, and polyester polyol (B), which is a reaction product of a composition containing polyhydric alcohol and a polycarboxylic acid, and the polyol (A) has a compound amount of 5% by mass or more and 30% by mass or less with respect to a total amount of the polyol (A) and the polyester polyol (B).
2. [Claim 2] The solvent-free adhesive according to claim 1, wherein an aromatic polycarboxylic acid has a compound amount of 25% by mass or more and 50% by mass or less with respect to the polycarboxylic acid.
3. [Claim 3] The solvent-free adhesive according to claim 1 or 2, wherein diethylene glycol has a compound amount of 50% by mass or more with respect to the polyhydric alcohol.
4. [Claim 4] The solvent-free adhesive according to any one of claims I to 3, wherein the polyester polyol (B) is lactone-modified.
5. [Claim 5] A laminate comprising: a first base material; a second base material; and an adhesive layer disposed between the first base material and the second base material, wherein the adhesive layer is a cured coating film of the solvent-free adhesive according to any one of claims I to 4.
6. [Claim 6] A packaging material comprising: the laminate according to claim 5.