Adhesives, laminates, packaging materials

Abstract

The present invention provides: an adhesive which is not susceptible to winding deviation and re-dissolution of a print layer; a laminate which is obtained using the adhesive; and a packaging material.　Provided are: a two-pack type curable adhesive which contains a polyisocyanate composition (X) that contains a polyisocyanate compound (A), and a polyol composition (Y) that contains a polyol (B) and an amino group-containing compound (C), wherein the polyisocyanate compound (A) contains a polyurethane polyisocyanate (A1) that is a reaction product of a non-aromatic isocyanate derivative having a viscosity of 1,500 mPa∙s or less at 60°C and a polyester polyol, and the amino group-containing compound (C) includes at least one compound that is selected from among a polyamine (C1) which has a plurality of primary or secondary amino groups and a compound (C2) which has a tertiary amino group and a plurality of hydroxyl groups; a laminate which is obtained by using the adhesive; and a packaging material.

Description

[Technical Field]

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

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

[0003] Conventionally, laminates used in packaging materials have mainly been obtained by the dry lamination method, in which an adhesive dissolved in a volatile organic solvent (sometimes referred to as a solvent-based laminating adhesive) is applied to a substrate, the organic solvent is evaporated as the substrate passes through an oven, and another substrate is then bonded to the substrate. However, in recent years, from the perspective of reducing environmental impact and improving the working environment, there has been an increasing demand for reactive two-component laminating adhesives (hereinafter referred to as solvent-free adhesives) that do not contain volatile organic solvents (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-159548 Summary of the Invention [Problem to be solved by the invention]

[0005] Solvent-free adhesives have many advantages, such as no drying process and no solvent emissions, they are energy-efficient and have low running costs, and there is no concern about solvent remaining in the laminate after bonding plastic films together or after bonding a plastic film to metal foil or a metal-vapor-deposited layer, but they also have disadvantages.

[0006] Unlike solvent-based adhesives, the polyisocyanate compounds and polyol compounds used in solventless adhesives must have a viscosity that allows them to be applied without diluting with an organic solvent, which inevitably necessitates a low molecular weight. However, if the molecular weight of the polyisocyanate compound or polyol compound is reduced, the initial cohesive strength also decreases, which can lead to problems such as misalignment of the adhesive surfaces of the rolled laminate film immediately after laminating the films together (winding slippage). It is possible to increase the molecular weight of the polyisocyanate compound or polyol compound to a certain extent and apply it at a high temperature, but this would result in greater damage to the film.

[0007] Furthermore, in laminates for packaging materials, a printed layer is generally formed using printing ink on the back side (the side facing the contents) of the substrate, which is the outermost layer (as viewed from the contents), and the printed layer is bonded to other substrates via an adhesive. However, some solvent-free adhesives containing low-molecular-weight polyisocyanate compounds tend to redissolve the printed layer.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide an adhesive that is less likely to cause misalignment or re-dissolution of the printed layer, and a laminate and packaging material obtained using the adhesive. [Means for solving the problem]

[0009] The present invention relates to a two-component curing adhesive comprising a polyisocyanate composition (X) containing a polyisocyanate compound (A) and a polyol composition (Y) containing a polyol (B) and an amino group-containing compound (C), in which the polyisocyanate compound (A) comprises a polyurethane polyisocyanate (A1) that is a reaction product of a non-aromatic isocyanate derivative having a viscosity of 1500 mPa·s or less at 60°C with a polyester polyol, and the amino group-containing compound (C) comprises at least one selected from a polyamine (C1) having multiple primary or secondary amino groups and a compound (C2) having a tertiary amino group and multiple hydroxyl groups. [Effects of the Invention]

[0010] The adhesive of the present invention can prevent miswinding and re-dissolution of the printed layer, thereby providing a laminate and a packaging material in which these problems are prevented. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Adhesive> The adhesive of the present invention is a two-component curing adhesive containing a polyisocyanate composition (X) and a polyol composition (Y). The adhesive of the present invention will be described in detail below.

[0012] (Polyisocyanate composition (X)) The polyisocyanate composition (X) used in the adhesive of the present invention contains a polyisocyanate compound (A). The polyisocyanate compound (A) contains, as an essential component, a polyurethane polyisocyanate (A1) which is a reaction product of a non-aromatic isocyanate derivative having a viscosity of 1500 mPa s or less at 60°C with a polyester polyol.

[0013] The isocyanate derivative used in the synthesis of polyurethane polyisocyanate (A1) can be any of biuret, nurate, adduct, allophanate, carbodiimide-modified, and uretdione-modified non-aromatic diisocyanates, and is not particularly limited as long as it has a viscosity of 1500 mPa·s or less at 60°C. A single non-aromatic isocyanate derivative may be used, or two or more may be used in combination. When two or more non-aromatic isocyanate derivatives are used in combination, a mixture with a viscosity of 1500 mPa·s or less at 60°C is used. The viscosity in this application is measured using a rotational viscometer with a cone and plate setting of 1°C x 50 mm diameter and a shear rate of 100 sec. -1 , values ​​measured at 60°C±0.5°C.

[0014] Examples of non-aromatic diisocyanates include aromatic aliphatic diisocyanates (aliphatic isocyanates having one or more aromatic rings in the molecule) such as m- or p-xylylene diisocyanate (also known as XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (also known as TMXDI), and aliphatic diisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate (also known as PDI), 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate (also known as LDI). Examples of such isocyanates include alicyclic diisocyanates such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebiscyclohexyl isocyanate (also known as hydrogenated MDI or HMDI), 1,3-bis(isocyanatomethyl)cyclohexane (also known as hydrogenated XDI or HXDI), and norbornane diisocyanate (also known as NBDI), and these can be used alone or in combination of two or more.

[0015] Examples of polyols that can be used in the synthesis of the adduct include glycols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol;

[0016] trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and 1,3,5-tris(2-hydroxyethyl)isocyanurate; Bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; Dimer diol;

[0017] polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of a polymerization initiator such as the above-mentioned glycols and trifunctional or tetrafunctional aliphatic alcohols;

[0018] polyester polyols (1) which are reaction products of polyesters obtained by ring-opening polymerization of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone with polyhydric alcohols such as the above-mentioned glycols, glycerin, trimethylolpropane, and pentaerythritol; Polyester polyol (2) obtained by reacting a bifunctional polyol such as the glycol, dimer diol, or bisphenol with a polycarboxylic acid: (3) a polyester polyol obtained by reacting a trifunctional or tetrafunctional aliphatic alcohol with a polycarboxylic acid; (4) a polyester polyol obtained by reacting a difunctional polyol with the trifunctional or tetrafunctional aliphatic alcohol and a polycarboxylic acid; Polyester polyols (5), which are polymers of hydroxyl acids such as dimethylolpropionic acid and castor oil fatty acid;

[0019] a polyether polyurethane polyol obtained by polymerizing the polyether polyol with an isocyanate compound; a polyester polyether polyurethane polyol obtained by reacting at least one of the polyester polyols (1) to (5), a polyether polyol, and an isocyanate compound; polyester polyurethane polyols obtained by polymerizing polyester polyols (1) to (5) with an isocyanate compound;

[0020] Examples include castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil which is a hydrogenated castor oil, and castor oil-based polyols such as 5 to 50 mole alkylene oxide adducts of castor oil, and mixtures thereof, and these can be used alone or in combination of two or more kinds.

[0021] Examples of polycarboxylic acids that can be used in the synthesis of the polyester polyols (2) to (4) include aromatic polybasic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride; Methyl esters of aromatic polybasic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate;

[0022] aliphatic polybasic acids such as malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, and dimer acid; Alkyl esters of aliphatic polybasic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0023] Examples of the alicyclic polybasic acids include 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic-1,2-anhydride, himic acid anhydride, and HET acid anhydride, and these may be used alone or in combination of two or more.

[0024] The compound used for synthesizing the allophanate is preferably a monool or a diol, and the diol may be the same as that used for synthesizing the adduct.

[0025] Examples of monools include aliphatic monools such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, lauryl alcohol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, nonadecanol, other alkanols (C20 to C50), oleyl alcohol, and isomers thereof;

[0026] Cyclohexanol, methylcyclohexanol, 4-butylcyclohexanol, 4-pentylcyclohexanol, 4-hexylcyclohexanol, cyclodecanol, cyclododecanol, cyclopentadecanol, 4-isopropylcyclohexanol, 3,5,5-trimethylcyclohexanol, menthol, 2-norbornanol, borneol, 2-adamantanol, dicyclohexylmethanol, decitol, 2-cyclohexylcyclohexanol, 4-cyclohexylcyclohexanol, 4-(4-propylcyclohexyl)cyclohexanol, 4-(4-pentylcyclohex alicyclic monools such as cyclohexanol, α-ambrinol, desoxycorticosterone, 11-dehydrocorticosterone, cholesterol, β-sitosterol, campesterol, stigmasterol, brassicasterol, lanosterol, ergosterol, β-cholestanol, testosterone, estrone, digitoxigenin, dehydroepiandrosterone, coprostanol, pregnenolone, epicholestanol, 7-dehydrocholesterol, estradiol benzoate, tigogenin, hecogenin, methandienone, cortisone acetate, stenolone, and isomers thereof;

[0027] aromatic aliphatic monools such as benzyl alcohol,

[0028] Examples of the polyoxyalkylene monool include polyoxyalkylene monools obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using an alkyl compound containing one active hydrogen as an initiator.

[0029] The polyester polyol used in the synthesis of polyurethane polyisocyanate (A1) is a reaction product of a polyhydric alcohol and a polycarboxylic acid. Examples of polyhydric alcohols 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, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol;

[0030] Examples include trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and 1,3,5-tris(2-hydroxyethyl)isocyanurate.

[0031] As the polycarboxylic acid, the same ones as those exemplified as the raw materials for the polyester polyols (2) to (4) can be used.

[0032] The polyester polyol used in the synthesis of the polyurethane polyisocyanate (A1) is preferably one synthesized using an aromatic polycarboxylic acid as the polycarboxylic acid, which allows the viscosity of the polyurethane polyisocyanate (A1) to be efficiently increased while maintaining the NCO%.

[0033] The number average molecular weight of the polyester polyol used in the synthesis of the polyurethane polyisocyanate (A1) can be adjusted as appropriate, but is, for example, 400 or more and 10,000 or less.

[0034] The polyurethane polyisocyanate (A1) is obtained by reacting a non-aromatic isocyanate derivative with a polyester polyol under conditions in which the isocyanate groups of the non-aromatic isocyanate derivative are in excess relative to the hydroxyl groups of the polyester polyol. The equivalent ratio of isocyanate groups to hydroxyl groups [NCO] / [hydroxyl groups] can be appropriately adjusted, but is, for example, from 2.0 to 20.0.

[0035] The polyisocyanate compound (A) may contain a polyisocyanate compound (A2) other than the polyurethane polyisocyanate (A1). Examples of the polyisocyanate compound (A2) include biurets, nurates, adducts, and allophanates of aromatic or non-aromatic diisocyanates, and polyurethane polyisocyanates that are reaction products of these diisocyanates with high-molecular-weight polyols (such as polyester polyols and polyether polyols). Among these, derivatives of non-aromatic diisocyanates are preferred.

[0036] Examples of non-aromatic diisocyanates include those exemplified as raw materials for polyurethane polyisocyanate (A1). Examples of aromatic diisocyanates include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (also known as MDI), polymethylene polyphenyl polyisocyanate (also known as polymeric MDI or crude MDI), 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate (also known as PPDI), 2,4-triisocyanate, ... Examples include diisocyanate, 2,6-tolylene diisocyanate (also known as TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, tolidine diisocyanate (also known as TODI), dianisidine diisocyanate, naphthalene diisocyanate (also known as NDI), 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

[0037] When a polyisocyanate compound (A2) is used, the polyisocyanate compound (A2) is preferably at least one selected from biuret, nurate, adduct, and allophanate forms of non-aromatic diisocyanates, and polyurethane polyisocyanates which are reaction products with high-molecular-weight polyols (polyester polyols, polyether polyols, etc.). Of the non-aromatic isocyanate derivatives used as raw materials for the polyurethane polyisocyanate (A1), excess may remain in the polyisocyanate composition (X) as polyisocyanate (A2), or a non-aromatic isocyanate derivative other than that used as a raw material for the polyurethane polyisocyanate (A1) may be used.

[0038] In the polyisocyanate composition (X) of the present invention, the proportion of the polyurethane polyisocyanate (A1) in the polyisocyanate compound (A) is preferably 15% by mass or more, and more preferably 20% by mass or more, thereby making it possible to more reliably obtain an adhesive that is less likely to cause slippage during winding or redissolution of the printed layer.

[0039] The polyisocyanate composition (X) used in the present invention preferably contains diisocyanate monomers such as the aromatic diisocyanates or non-aromatic diisocyanates exemplified above in an amount of 1% by mass or less.

[0040] The isocyanate composition (X) preferably has a viscosity at 60°C of 300 mPa·s or more and 6000 mPa·s or less, and more preferably 300 mPa·s or more and 3000 mPa·s or less.

[0041] (Polyol composition (Y)) The polyol composition (Y) contains a polyol (B) having multiple hydroxyl groups and an amino group-containing compound (C).

[0042] Examples of the polyol (B) include polyether polyol (B1), polyester polyol (B2), vegetable oil polyol (B3), polyurethane polyol (B4), etc., and these can be used alone or in combination of two or more.

[0043] Examples of the polyether polyol (B1) include those obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of a polymerization initiator such as glycols (e.g., ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol), and trifunctional or tetrafunctional aliphatic alcohols (e.g., glycerin, trimethylolpropane, pentaerythritol, and polypropylene glycol triols). Polypropylene polyol is preferably used.

[0044] The polyester polyol (B2) is a reaction product of a polyhydric alcohol and a polycarboxylic acid. The polyhydric alcohol used in the synthesis of the polyester polyol (B2) may be a diol or a tri- or higher functional polyol. Examples of the diol include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, and 2,2,4-trimethyl-1,3-pentanediol;

[0045] ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol; Modified polyether diols obtained by ring-opening polymerization of aliphatic diols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;

[0046] Lactone-based polyester polyols obtained by polycondensation reaction of aliphatic diols with various lactones such as lactanoids and ε-caprolactone;

[0047] Bisphenols such as bisphenol A and bisphenol F;

[0048] Examples include alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc. to bisphenols such as bisphenol A and bisphenol F.

[0049] Trifunctional or higher polyols include aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

[0050] modified polyether polyols obtained by ring-opening polymerization of aliphatic polyols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;

[0051] Examples include lactone-based polyester polyols obtained by polycondensation reaction of aliphatic polyols with various lactones such as ε-caprolactone.

[0052] Examples of polycarboxylic acids used in the synthesis of the polyester polyol (B2) include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid; and anhydrides or ester-forming derivatives of these aliphatic or dicarboxylic acids; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acids.

[0053] Examples of the vegetable oil polyol (B3) include castor oil, dehydrated castor oil, hardened castor oil which is a hydrogenated castor oil, and an alkylene oxide 5 to 50 mole adduct of castor oil.

[0054] The polyurethane polyol (B4) is a reaction product of a low-molecular-weight or high-molecular-weight polyol and a polyisocyanate compound. The low-molecular-weight polyol may be the same polyhydric alcohol as exemplified as a raw material for the polyester polyol (B2). Examples of the high-molecular-weight polyol include polyether polyol (B1) and polyester polyol (B2). The polyisocyanate compound may be any of the various diisocyanates and derivatives thereof exemplified as raw materials for the polyurethane polyisocyanate (A1) and the polyisocyanate compound (A2).

[0055] The polyol (B) preferably contains at least one selected from the group consisting of polyether polyol (B1) and polyester polyol (B2), and also preferably contains both polyether polyol (B1) and polyester polyol (B2).

[0056] The number average molecular weight of the polyol (B) is not particularly limited, but is preferably, for example, from 300 to 4000. The number average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) under the following conditions.

[0057] Measuring device: Tosoh Corporation HLC-8320GPC Column: Tosoh Corporation TSKgel 4000HXL, TSKgel 3000HXL, TSKgel 2000HXL, TSKgel 1000HXL Detector: RI (differential refractometer) Data processing: Tosoh Corporation Multistation GPC-8020modelII Measurement conditions: Column temperature 40°C Solvent: Tetrahydrofuran Flow rate 0.35ml / min Standard: Monodisperse polystyrene Sample: 100 μl of tetrahydrofuran solution containing 0.2% by mass of resin solids filtered through a microfilter

[0058] The amino group-containing compound (C) includes at least one member selected from a polyamine (C1) having a plurality of primary or secondary amino groups and a compound (C2) having a tertiary amino group and a plurality of hydroxyl groups.

[0059] As the amino group-containing compound (C), known compounds can be used without any particular limitation. Examples of the polyamine (C1) having a plurality of primary or secondary amino groups include methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropanamine-2,4,8,10-tetraoxaspirodoundecane, lysine, 2,2,4-trimethylhexamethylenediamine, hydrazine, piperazine, 2-hydroxyethylethylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, 1,3-diaminopropane,

[0060] 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bishexamethylenetriamine, 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornadiamine,

[0061] Examples include bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, menthenediamine, bis(cyanoethyl)diethylenetriamine, 1,4-bis-(8-aminopropyl)-piperazine, 1-(2'-aminoethylpiperazine), 1-[2'-(2"-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyurea amines which are reaction products of the above-mentioned various polyamines with the above-mentioned various isocyanate components.

[0062] Examples of the compound (C2) having a tertiary amino group and multiple hydroxyl groups include those obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene using, as a polymerization initiator, primary or secondary alkylamines such as ethylamine and diethylamine, amine compounds having multiple amino groups such as methylenediamine and ethylenediamine, and amine compounds having active hydrogen groups such as primary or secondary alkanolamines such as monoethanolamine and diethanolamine.

[0063] The amount of the amino group-containing compound (C) is preferably adjusted so that the amine value of the polyol composition (Y) is 1 mgKOH / g or more and 100 mgKOH / g or less, and more preferably 20 mgKOH / g or more and 80 mgKOH / g or less.

[0064] In this specification, the amine value refers to the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1 g of sample, and is not particularly limited and can be calculated using known methods. When the chemical structure of the amino group-containing compound (C) and, if necessary, the average molecular weight, etc. are known, the amine value can be calculated by (number of amino groups per molecule / average molecular weight) x 56.1 x 1000. When the chemical structure, average molecular weight, etc. of the amino group-containing compound (C) are unknown, the amine value can be measured according to known methods for measuring amine value, for example, JIS K7237-1995.

[0065] The polyol composition (Y) may further contain a monool compound (D) having one alcoholic hydroxyl group. The main chain of the monool compound (D) is not particularly limited, and examples thereof include vinyl resins, acrylic resins, polyesters, epoxy resins, and urethane resins having one hydroxyl group. Aliphatic alcohols, alkyl alkylene glycols, and the like can also be used. The main chain of the monool compound (D) may be linear or branched. The bonding position of the hydroxyl group is not particularly limited, but it is preferably present at the terminal of the molecular chain.

[0066] Specific examples of such monool compounds (D) include aliphatic monools such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, lauryl alcohol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, nonadecanol, other alkanols (C20 to C50), oleyl alcohol, and isomers thereof;

[0067] Cyclohexanol, methylcyclohexanol, 4-butylcyclohexanol, 4-pentylcyclohexanol, 4-hexylcyclohexanol, cyclodecanol, cyclododecanol, cyclopentadecanol, 4-isopropylcyclohexanol, 3,5,5-trimethylcyclohexanol, menthol, 2-norbornanol, borneol, 2-adamantanol, dicyclohexylmethanol, decitol, 2-cyclohexylcyclohexanol, 4-cyclohexylcyclohexanol, 4-(4-propylcyclohexyl)cyclohexanol, 4-(4-pentylcyclohex alicyclic monools such as cyclohexanol, α-ambrinol, desoxycorticosterone, 11-dehydrocorticosterone, cholesterol, β-sitosterol, campesterol, stigmasterol, brassicasterol, lanosterol, ergosterol, β-cholestanol, testosterone, estrone, digitoxigenin, dehydroepiandrosterone, coprostanol, pregnenolone, epicholestanol, 7-dehydrocholesterol, estradiol benzoate, tigogenin, hecogenin, methandienone, cortisone acetate, stenolone, and isomers thereof;

[0068] aromatic aliphatic monools such as benzyl alcohol,

[0069] Examples of the polyoxyalkylene monool include polyoxyalkylene monools obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using an alkyl compound containing one active hydrogen as an initiator.

[0070] The amount of the mono-ol compound (D) to be blended is adjusted as appropriate. When the adhesive used in the present invention contains the mono-ol compound (D), the amount is, for example, 30 mass % or less of the total amount of the adhesive.

[0071] The viscosity of the polyol composition (Y) at 50°C is preferably 50 mPa·s or more and 180 mPa·s or less. The viscosity of the polyol composition (Y) can be adjusted by the skeleton of the polyol (B) or the plasticizer described below. When adjusting the skeleton of the polyol (B), the viscosity can be reduced by using, for example, polypropylene glycol or a polyester polyol obtained by reacting an aliphatic carboxylic acid with a polyol. Alternatively, the viscosity can be increased by using a polyester polyol obtained by reacting an aromatic carboxylic acid with a polyol.

[0072] (Other components of adhesive) The adhesive of the present invention may contain components other than those described above. The other components may be contained in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or may be prepared separately and mixed with the polyisocyanate composition (X) and the polyol composition (Y) immediately before application of the adhesive. Examples of such components include catalysts, acid anhydrides, coupling agents, pigments, plasticizers, phosphoric acid compounds, and hydroxycarboxylic acids. Each component will be described below.

[0073] Examples of the catalyst include metal catalysts, amine catalysts, and aliphatic cyclic amide compounds.

[0074] Examples of the metal catalyst include metal complex catalysts, inorganic metal catalysts, and organic metal catalysts. Examples of the metal complex catalyst include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate.

[0075] Examples of inorganic metal catalysts include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, and the like.

[0076] Examples of the organometallic catalyst include organic zinc compounds such as zinc octylate, zinc neodecanoate, and zinc naphthenate; organic tin compounds such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organic nickel compounds such as nickel octylate and nickel naphthenate; organic cobalt compounds such as cobalt octylate and cobalt naphthenate; organic bismuth compounds such as bismuth octylate, bismuth neodecanoate, and bismuth naphthenate; titanium compounds such as tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanium, butoxytitanium trichloride, aliphatic diketones, aromatic diketones, and titanium chelate complexes having at least one alcohol having 2 to 10 carbon atoms as a ligand.

[0077] Examples of amine catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl)isopropanolamine, Propanolamine, 3-quinuclidinol, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazole, 1 ,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 1-(2-hydroxypropyl)-2-methylimidazole, etc.

[0078] Examples of the aliphatic cyclic amide compound include δ-valerolactam, ε-caprolactam, ω-enantholactam, η-capryllactam, β-propiolactam, etc. Among these, ε-caprolactam is more effective in accelerating curing.

[0079] An organometallic catalyst is preferably used, preferably at least one selected from an organozinc compound, an organotin compound, and an organobismuth compound, and preferably an organotin compound. The amount of the organometallic catalyst is preferably 0.005% by mass or more and 1.0% by mass or less of the total adhesive. When the organometallic catalyst is an organozinc compound, its amount is preferably 0.05% by mass or more and 1.0% by mass or less of the total adhesive, and when the organometallic catalyst is an organotin compound, its amount is preferably 0.005% by mass or more and 0.5% by mass or less of the total adhesive. When the organometallic catalyst is an organobismuth compound, its amount is preferably 0.05% by mass or more and 1.0% by mass or less of the total adhesive.

[0080] Examples of the acid anhydride include cyclic aliphatic acid anhydrides, aromatic acid anhydrides, unsaturated carboxylic acid anhydrides, etc., and these can be used alone or in combination of two or more. More specifically, for example, phthalic acid anhydride, trimellitic acid anhydride, pyromellitic acid anhydride, benzophenonetetracarboxylic acid anhydride, dodecenylsuccinic acid anhydride, polyadipic acid anhydride, polyazelaic acid anhydride, polysebacic acid anhydride, poly(ethyloctadecanedioic acid) anhydride, poly(phenylhexadecanedioic acid) anhydride, tetrahydrophthalic acid anhydride, methyltetrahydrophthalic acid anhydride, methylhexahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, methylhimic acid anhydride, trialkyltetrahydrophthalic acid anhydride, Examples of the dicarboxylic acid anhydride include methylcyclohexene dicarboxylic acid anhydride, methylcyclohexene tetracarboxylic acid anhydride, ethylene glycol bistrimellitate dianhydride, HET anhydride, Nadic anhydride, methylnadic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, and 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride.

[0081] Alternatively, the acid anhydride may be one obtained by modifying the above-mentioned compounds with glycol. Examples of glycols that can be used for modification include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol; and polyether glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Furthermore, copolymer polyether glycols of two or more of these glycols and / or polyether glycols may also be used.

[0082] Examples of the coupling agent include a silane coupling agent, a titanate-based coupling agent, and an aluminum-based coupling agent.

[0083] Examples of silane coupling agents include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, and the like.

[0084] Examples of titanate coupling agents include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxytitanium.

[0085] Examples of aluminum-based coupling agents include acetoalkoxyaluminum diisopropylate.

[0086] The pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments such as extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, and pearlescent pigments listed in the Paint Raw Materials Handbook 1970 Edition (compiled by the Japan Paint Manufacturers Association), as well as plastic pigments.

[0087] Examples of extender pigments include precipitated barium sulfate, powdered barium sulfate, precipitated calcium carbonate, calcium bicarbonate, kansui stone, alumina white, silica, hydrous fine powdered silica (white carbon), ultrafine powdered anhydrous silica (aerosil), silica sand, talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and yellow ochre.

[0088] Specific examples of organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, and Lake 4R; soluble azo pigments such as Lake C, Carmine 6B, and Bordeaux 10; various (copper) phthalocyanine pigments such as Phthalocyanine Blue and Phthalocyanine Green; various chlorine dye lakes such as Rhodamine Lake and Methyl Violet Lake; various mordant dye pigments such as Quinoline Lake and Fast Sky Blue; various vat dye pigments such as Anthraquinone pigments, Thioindigo pigments, and Perinone pigments; various quinacridone pigments such as Synchasia Red B; various dioxazine pigments such as Dioxazine Violet; various condensed azo pigments such as Chromophtal; and aniline black.

[0089] Examples of inorganic pigments include various chromates such as yellow lead, zinc chromate, and molybdate orange; various ferrocyanide compounds such as Prussian blue; various metal oxides such as titanium oxide, zinc white, Mapico yellow, iron oxide, red iron oxide, chrome oxide green, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; flake pigments of these metals, mica flake pigments; metallic pigments and pearl pigments such as mica flake pigments coated with metal oxides and micaceous iron oxide pigments; graphite, carbon black, and the like.

[0090] Examples of plastic pigments include "Grandol PP-1000" and "PP-2000S" manufactured by DIC Corporation.

[0091] The pigment to be used may be selected appropriately depending on the purpose. For example, inorganic oxides such as titanium oxide and zinc oxide are preferably used as white pigments because they have excellent durability, weather resistance, and design properties, and carbon black is preferably used as black pigments.

[0092] The amount of pigment to be blended is, for example, 1 to 400 parts by mass per 100 parts by mass of the total amount of nonvolatile components of the polyol composition (X) and the polyisocyanate composition (Y), and is more preferably 10 to 300 parts by mass to improve adhesion and blocking resistance.

[0093] 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.

[0094] Examples of phthalic acid plasticizers include phthalic acid ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, octyldecyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and diisooctyl isophthalate; and tetrahydrophthalic acid ester plasticizers such as di-(2-ethylhexyl) tetrahydrophthalate, di-n-octyl tetrahydrophthalate, and diisodecyl tetrahydrophthalate.

[0095] Examples of fatty acid plasticizers include adipic acid plasticizers such as di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyl diglycol adipate; azelaic acid plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, and diisooctyl azelate; and di-n-butyl sebacate and di-(2 Sebacic acid plasticizers such as di-n-butyl maleate, di-(2-ethylhexyl) sebacate, and diisononyl sebacate; maleic acid plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate, and di-(2-ethylhexyl) maleate; fumaric acid plasticizers such as di-n-butyl fumarate and di-(2-ethylhexyl) fumarate; monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, and dibutyl itaconate; Examples of suitable plasticizers include itaconic acid-based plasticizers such as itaconate and di-(2-ethylhexyl) itaconate; stearic acid-based plasticizers such as n-butyl stearate, glycerin monostearate, and diethylene glycol distearate; oleic acid-based plasticizers such as butyl oleate, glyceryl monooleate, and diethylene glycol monooleate; citric acid-based plasticizers such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, and acetyl tri-(2-ethylhexyl) citrate; ricinoleic acid-based plasticizers such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, glyceryl monoricinoleate, and diethylene glycol monoricinoleate; and other fatty acid-based plasticizers such as diethylene glycol monolaurate, diethylene glycol dipelargonate, and pentaerythritol fatty acid esters.

[0096] Examples of aromatic polycarboxylic acid plasticizers include trimellitic acid plasticizers such as tri-n-hexyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, and triisodecyl trimellitate; and pyromellitic acid plasticizers such as tetra-(2-ethylhexyl) pyromellitate and tetra-n-octyl pyromellitate.

[0097] Examples of phosphoric acid plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, cresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate, and tris(isopropylphenyl) phosphate.

[0098] Examples of polyol-based plasticizers include glycol-based plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethylbutyrate), triethylene glycol di-(2-ethylhexoate), and dibutylmethylene bisthioglycolate; and glycerin-based plasticizers such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.

[0099] Examples of epoxy plasticizers include epoxidized soybean oil, epoxy butyl stearate, di-2-ethylhexyl epoxy hexahydrophthalate, diisodecyl epoxy hexahydrophthalate, epoxy triglyceride, epoxidized octyl oleate, and epoxidized decyl oleate.

[0100] Examples of polyester plasticizers include adipic acid polyesters, sebacic acid polyesters, and phthalic acid polyesters.

[0101] Examples of carbonate plasticizers include propylene carbonate and ethylene carbonate.

[0102] Other examples of the plasticizer include partially hydrogenated terphenyls, adhesive plasticizers, and polymerizable plasticizers such as diallyl phthalate, acrylic monomers and oligomers, etc. These plasticizers can be used alone or in combination of two or more.

[0103] Examples of the phosphoric acid compound include phosphoric acid, pyrophosphoric acid, triphosphoric acid, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate.

[0104] It is also preferable to contain at least one selected from the group consisting of 2,2-dimethylolacetic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolpentanoic acid, as this improves adhesion to metal substrates. The amount of hydroxycarboxylic acid blended 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, of the polyol composition (Y).

[0105] (Adhesive Form) The adhesive of the present invention is particularly effective when used in a solventless form, but can also be used as a solvent-based adhesive. In this specification, the term "solvent-based adhesive" refers to a form used in a method in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating, and then laminated to another substrate, a method known as dry lamination. Examples of solvents that can be used include toluene, xylene, methylene chloride, tetrahydrofuran, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, acetone, methyl ethyl ketone (MEK), cyclohexanone, toluene, xylol, n-hexane, and cyclohexane. Either one or both of the polyisocyanate composition (X) and the polyol composition (Y) contain the organic solvent described above. In the case of a solvent-based adhesive, the solvent used as a reaction medium during the production of the components of the polyisocyanate composition (X) or the polyol composition (Y) may also be used as a diluent during coating.

[0106] A solventless adhesive is a form used in the so-called non-solvent lamination method, in which the adhesive is applied to a substrate and then bonded to another substrate without heating in an oven or other device to volatilize the solvent. Neither the polyisocyanate composition (X) nor the polyol composition (Y) contains substantially any of the organic solvents listed above. This is considered to be essentially free of organic solvents 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 in the production of the components or raw materials of the polyisocyanate composition (X) or polyol composition (Y). Furthermore, if the polyol composition (Y) contains a low-molecular-weight alcohol, the low-molecular-weight alcohol reacts with the polyisocyanate composition (X) and becomes part of the coating film, eliminating the need for evaporation after application. Therefore, such a form is also considered a solventless adhesive.

[0107] The adhesive of the present invention is preferably used by blending the polyisocyanate composition (X) with the polyol composition (Y) so that the ratio of the number of moles of isocyanate groups (NCO) to the number of moles of active hydrogen groups (hydroxyl groups, amino groups), [NCO] / [OH+NH], is 1.0 to 3.0, which allows for appropriate curing properties to be obtained without depending on the environmental humidity at the time of application.

[0108] <Laminate> The adhesive of the present invention can be suitably used for producing laminates, particularly laminates for food packaging. Such laminates are obtained by bonding multiple substrates (films or papers) together using the above-mentioned adhesive. There are no particular limitations on the film used, and a film can be appropriately selected depending on the application. For example, for food packaging, polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, polyethylene film (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film, MDOPE: uniaxially oriented polyethylene film, OPE: biaxially oriented polyethylene film), polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyolefin film such as a gas barrier film in which an olefin-based heat-sealable resin layer is provided on one or both sides of a resin having gas barrier properties such as ethylene-vinyl alcohol copolymer or polyvinyl alcohol, polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, etc. can be mentioned.

[0109] It is also preferable to use a film made of a material containing biomass-derived components. Biomass films are commercially available from various companies, and for example, sheets such as those listed in the list of biomass-certified products listed by the Japan Organics Recycling Association can be used.

[0110] Specifically, well-known films are made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass as a raw material. For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol into ethylene oxide by a conventionally known method to produce ethylene glycol. Alternatively, commercially available biomass ethylene glycol may be used; for example, biomass ethylene glycol commercially available from India Glycoal Limited can be suitably used.

[0111] Alternatively, products made from biomass materials are also available, classified by their biomass plastic content as specified by ISO 16620 or ASTM D6866. Radioactive carbon-14C exists in the atmosphere at a rate of 1 in 1012 particles, and this rate remains the same for atmospheric carbon dioxide, so this rate remains the same even in plants that fix this carbon dioxide through photosynthesis. Therefore, the carbon in plant-derived resins contains radioactive carbon-14C. In contrast, the carbon in fossil fuel-derived resins contains almost no radioactive carbon-14C. Therefore, by measuring the concentration of radioactive carbon-14C in the resin using an accelerator mass spectrometer, the plant-derived resin content, or biomass plastic content, can be determined. Examples of plant-derived low-density polyethylene that is a biomass plastic having a biomass plastic content of 80% or more, preferably 90% or more as specified by ISO 16620 or ASTM D6866 include products manufactured by Braskem under the trade names "SBC818," "SPB608," "SBF0323HC," "STN7006," "SEB853," and "SPB681," and films using these as raw materials can be suitably used.

[0112] The film may be one that has been subjected to a stretching treatment. A typical stretching method involves melt-extruding a resin into a sheet using an extrusion film-forming method or the like, followed by simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then transverse stretching. Specifically, a method that combines longitudinal stretching utilizing the speed difference between rolls and transverse stretching using a tenter is often used.

[0113] The film surface may be subjected to various surface treatments such as flame treatment and corona discharge treatment as necessary so that an adhesive layer without defects such as film breakage or repellency is formed.

[0114] Alternatively, inorganic vapor-deposited films such as metal vapor-deposited films with a vapor-deposited layer of a metal such as aluminum, transparent vapor-deposited films with a vapor-deposited layer of a metal oxide such as silica or alumina, or barrier films containing a gas barrier layer such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, vinylidene chloride, etc. Using such films can provide a laminate with barrier properties against water vapor, oxygen, alcohol, inert gases, volatile organic compounds (fragrances), etc.

[0115] The paper can be made from any known paper base material without any particular limitations. Specifically, it can be made using natural fibers for papermaking, such as wood pulp, on a known papermaking machine, but the papermaking conditions are not particularly specified. Examples of natural fibers for papermaking include wood pulp, such as softwood pulp and hardwood pulp; non-wood pulp, such as Manila hemp pulp, sisal hemp pulp, and flax pulp; and chemically modified versions of these pulps. Examples of pulp that can be used include chemical pulp produced by sulfate cooking, acidic, neutral, or alkaline sulfite cooking, or soda cooking, ground pulp, chemi-ground pulp, and thermomechanical pulp. Commercially available fine paper, coated paper, lined paper, impregnated paper, cardboard, and paperboard can also be used.

[0116] Examples of the laminate structure include: (1) Substrate 1 / Adhesive layer 1 / Sealant film (2) Substrate 1 / Adhesive layer 1 / Metal-deposited unstretched film (3) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretched film (4) Transparent vapor-deposited stretched film / adhesive layer 1 / sealant film (5) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Sealant film (6) Substrate 1 / Adhesive layer 1 / Metal vapor-deposited stretched film / Adhesive layer 2 / Sealant film (7) Substrate 1 / Adhesive layer 1 / Transparent vapor-deposited stretched film / Adhesive layer 2 / Sealant film (8) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Sealant film (9) Substrate 1 / Adhesive layer 1 / Substrate 2 / Adhesive layer 2 / Metal layer / Adhesive layer 3 / Sealant film (10) Substrate 1 / Adhesive layer 1 / Metal layer / Adhesive layer 2 / Substrate 2 / Adhesive layer 3 / Sealant film These include, but are not limited to:

[0117] Examples of the substrate 1 used in structure (1) include MDOPE film, OPE film, OPP film, PET film, nylon film, and paper. The substrate 1 may also be coated to improve gas barrier properties or ink receptivity when a printing layer (described later) is provided. Examples of commercially available coated substrate films 1 include K-OPP film and K-PET film. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealant films include CPP film, LLDPE film, and gas-barrier heat-seal film. A printing layer may be provided on the surface of the substrate 1 facing the adhesive layer 1 (when a coated substrate film 1 is used, the surface of the coating layer facing the adhesive layer 1) or on the surface opposite the adhesive layer 1. The printing layer is formed using various printing inks, such as gravure ink, flexographic ink, offset ink, stencil ink, and inkjet ink, using a common printing method that has traditionally been used to print on polymer films and paper.

[0118] Examples of the substrate 1 used in structures (2) and (3) include MDOPE film, OPE film, OPP film, PET film, paper, etc. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of metal-vapor-deposited unstretched films include CPP film, LLDPE film, and VM-CPP film and VM-LLDPE film, which are gas-barrier heat-sealable films to which a metal such as aluminum has been vapor-deposited. Examples of metal-vapor-deposited stretched films include MDOPE film, OPE film, and VM-MDOPE film, VM-OPE film, and VM-OPP film, which are OPP film to which a metal such as aluminum has been vapor-deposited. As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0119] Examples of transparent vapor-deposited stretched films used in structure (4) include films obtained by depositing silica or alumina on MDOPE film, OPE film, OPP film, PET film, nylon film, etc. For the purpose of protecting the inorganic vapor-deposited layer of silica or alumina, a film with a coating on the vapor-deposited layer may also be used. The adhesive layer 1 is a cured coating of the adhesive of the present invention. Examples of sealant films include those similar to those in structure (1). A printed layer may be provided on the surface of the transparent vapor-deposited stretched film facing the adhesive layer 1 (when a film with a coating on the inorganic vapor-deposited layer is used, the surface of the coating layer facing the adhesive layer 1). The method of forming the printed layer is the same as in structure (1).

[0120] Examples of the substrate 1 used in structure (5) include PET film and paper. Examples of the substrate 2 include nylon film. At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0121] Examples of the substrate 1 in structure (6) include those similar to those in structures (2) and (3). Examples of metal-vapor-deposited stretched films include VM-MDOPE film, VM-OPE film, VM-OPP film, and VM-PET film, which are obtained by vapor-depositing a metal such as aluminum on an MDOPE film, OPE film, OPP film, or PET film. At least one of the adhesive layer 1 and the adhesive layer 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0122] Examples of the substrate 1 in structure (7) include PET film, paper, etc. Examples of the transparent vapor-deposited stretched film include those similar to those in structure (4). At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0123] Examples of the substrate 1 in structure (8) include PET film and paper. Examples of the metal layer include aluminum foil. At least one of the adhesive layers 1 and 2 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0124] Examples of the substrate 1 in structures (9) and (10) include PET film, paper, etc. Examples of the substrate 2 include nylon film, etc. Examples of the metal layer include aluminum foil, etc. At least one of the adhesive layers 1, 2, and 3 is a cured coating film of the adhesive of the present invention. Examples of the sealant film include those similar to those in structure (1). As in structure (1), a printed layer may be provided on either side of the substrate 1.

[0125] <Method of manufacturing laminate> The laminate of the present invention can be obtained, for example, by a method (dry lamination method, non-solvent lamination method) having a two-liquid mixing step in which the polyisocyanate composition (X) and the polyol composition (Y) are mixed in advance, then coated on a first substrate, the solvent is volatilized as necessary, and then a second substrate is laminated on the coated surface and the adhesive layer is cured; or by a method having a two-liquid separate coating step in which the polyisocyanate composition (X) and the polyol composition (Y) are separately applied to a first substrate and a second substrate, and then the coated surfaces are brought into contact with each other and pressed together to laminate the first substrate and the second substrate, and the adhesive layer is cured.

[0126] When the laminate of the present invention is produced by a method including a two-liquid mixing step, the laminate can be produced using a general non-solvent laminating device. The amount of application of the adhesive (a mixture of the polyisocyanate composition (X) and the polyol composition (Y)) is, for example, 0.5 to 5.0 g / m 2 The first substrate and the second substrate are bonded together by the pressure between the rolls as they pass between two rolls (laminating rolls), and the temperature of the laminating rolls is preferably from room temperature to about 80°C, and the pressure is preferably from about 0.05 to 0.5 MPa. After lamination, the adhesive cures at room temperature (20 to 25°C) or under heating, more specifically at 15 to 50°C, for 12 to 72 hours, and exhibits practical physical properties.

[0127] <Packaging material> The laminate described above can be suitably used as a packaging material, particularly as a packaging material for food packaging. The packaging material is obtained by forming the laminate described above into a bag and heat-sealing it to form the packaging material. Various types of packaging material are available, including three-sided sealed bags, four-sided sealed bags, gusseted packaging bags, pillow packaging bags, Goebel-top-type bottomed containers, Tetra Classic, Brueck-type containers, tube containers, paper cups, and lids. The packaging material may also be appropriately provided with an easy-opening treatment or resealing means.

[0128] The packaging material of the present invention can be suitably used not only for food applications but also as a packaging material for filling detergents and medicines. Specific applications include liquid laundry detergents, liquid kitchen detergents, liquid bath detergents, liquid bath soaps, liquid shampoos, liquid conditioners, pharmaceutical tablets, and the like. It can also be used as a secondary packaging material for packaging the above-mentioned containers. [Example]

[0129] The present invention will be described in more detail below with reference to specific synthesis examples and examples, but the present invention is not limited to these examples. In the following examples, "parts" and "%" represent "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0130] <Preparation of Polyisocyanate Composition (X)> (Synthesis of polyester polyol (I)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, distillation tube, water separator, etc. was charged with 48.9 parts of 3-methylpentanediol, 25.5 parts of adipic acid, 25.5 parts of isophthalic acid, and 0.01 parts of titanium tetraisopropoxide under nitrogen gas introduction, and the internal temperature was maintained at 250° C. by gradually heating so that the temperature at the top of the distillation tube did not exceed 100° C. The esterification reaction was terminated when the acid value reached 1 mg KOH / g or less, yielding a polyester polyol (I) with a number average molecular weight of 1,020 and a hydroxyl value of 109.7 mg KOH / g.

[0131] (Synthesis of polyester polyol (II)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, distillation tube, water separator, etc. was charged with 54.0 parts of 3-methylpentanediol, 46.0 parts of isophthalic acid, and 0.01 parts of titanium tetraisopropoxide under nitrogen gas introduction, and the internal temperature was maintained at 250° C. by gradually heating so that the temperature at the top of the distillation tube did not exceed 100° C. The esterification reaction was terminated when the acid value reached 1 mgKOH / g or less, yielding a polyester polyol (II) with a number average molecular weight of 500 and a hydroxyl value of 223.0 mgKOH / g.

[0132] (Synthesis of polyester polyol (III)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, distillation tube, water separator, etc. was charged with 52.9 parts of diethylene glycol, 47.1 parts of adipic acid, and 0.01 parts of titanium tetraisopropoxide under nitrogen gas introduction, and the internal temperature was maintained at 220° C. by gradually heating so that the temperature at the top of the distillation tube did not exceed 100° C. The esterification reaction was terminated when the acid value reached 1 mgKOH / g or less, yielding a polyester polyol (III) having a number average molecular weight of 460 and a hydroxyl value of 245.1 mgKOH / g.

[0133] (Synthesis of Polyisocyanate Composition (X-1)) A reaction vessel equipped with a stirrer, thermometer, and nitrogen gas inlet tube was charged with 87.0 parts of a nurate form of hexamethylene diisocyanate (Sumidur N3300, manufactured by Sumika Covestro Urethane Co., Ltd.) and heated to 60°C while stirring under a nitrogen gas stream. 13.0 parts of polyester polyol (I) were added dropwise in several batches, and the mixture was further heated and maintained at an internal temperature of 90°C for 6 hours to carry out a urethanization reaction, yielding a polyisocyanate composition (X-1) having an NCO group content of 17.8% and a viscosity at 60°C of 1149 mPa s, both of which had isocyanate groups.

[0134] (Synthesis of Polyisocyanate Compositions (X-2) to (X-7)) Polyisocyanate compositions (X-2) to (X-7) were obtained in the same manner as polyisocyanate composition (X-1), except that the non-aromatic isocyanate derivative and polyester polyol used were changed to those shown in Table 1.

[0135] In Table 1, N3300 is a nurate form of hexamethylene diisocyanate (Sumidur N3300, manufactured by Sumika Covestro Urethane Co., Ltd., NCO% is 21.8%), and its viscosity at 60°C is 282 mPa·s. D101 is a derivative of hexamethylene diisocyanate (Asahi Kasei Corporation, Duranate D-101, NCO% 19.7%) and has a viscosity of 74 mPa·s at 60°C. D-178NL is a derivative of hexamethylene diisocyanate (Takenate D-178NL, manufactured by Mitsui Chemicals, Inc., NCO% 19.0%) and has a viscosity of 23 mPa·s at 60°C.

[0136] (Polyisocyanate composition (X'-1)) A nurate form of hexamethylene diisocyanate (Sumidur N3300, manufactured by Sumika Covestro Urethane Co., Ltd., NCO% 21.8%) was used as polyisocyanate composition (X'-1).

[0137] (Polyisocyanate composition (X'-2)) A derivative of hexamethylene diisocyanate (Duranate D-101, manufactured by Asahi Kasei Corporation, NCO% 19.7%) was used as a polyisocyanate composition (X'-2).

[0138] (Polyisocyanate composition (X'-3)) A derivative of hexamethylene diisocyanate (Takenate D-178NL, manufactured by Mitsui Chemicals, Inc., NCO% 19.0%) was used as a polyisocyanate composition (X'-3).

[0139] [Table 1]

[0140] <Preparation of Polyol Composition (Y)> (Synthesis of polyester polyol (B2-1)) A reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet tube, distillation tube, water separator, etc. was charged with 54.0 parts of 3-methylpentanediol, 46.0 parts of isophthalic acid, and 0.01 parts of titanium tetraisopropoxide under nitrogen gas introduction, and the internal temperature was maintained at 250° C. by gradually heating so that the temperature at the top of the distillation tube did not exceed 100° C. The esterification reaction was terminated when the acid value reached 1 mg KOH / g or less, yielding a polyester polyol (B2-1) with a number average molecular weight of 500 and a hydroxyl value of 224.2 mg KOH / g.

[0141] (Preparation of Polyol Composition (Y-1)) Polyether polyol (B1) was 13.0 parts of polypropylene polyol (AGC, Exenol 430 (molecular weight = 400, hydroxyl value = 400, both catalog values)), 40.0 parts of polypropylene polyol (AGC, Exenol 420 (molecular weight = 400, hydroxyl value = 280), both catalog values), 30.0 parts of the polyester polyol (B2) synthesized above, 17.0 parts of polyoxypropylene triamine (Huntsman, Jeffamine T-403, molecular weight Mw = 440, amine value = 355 mg KOH / g, both catalog values) as polyamine (C1), and 0.1 parts of dibutyltin dilaurate to prepare a polyol composition (Y-1). The amine value of the polyol composition (Y-1) was 60.7 mg KOH / g.

[0142] <Evaluation> (Print layer resolubility) A urethane-based laminating ink (Finart R794 White G3; manufactured by DIC Corporation) was adjusted to 15 seconds (25°C) using a Rigo Zahn Cup #3 printer and printed onto a corona-treated PET (polyethylene terephthalate) film (Toyobo Ester Film E5102#12) using a gravure printing press equipped with a 43 μm deep gravure plate. The print was then dried or cured by passing through a 70°C oven to form a printed layer on the PET film.

[0143] A drop of polyisocyanate composition (X-1) was placed on the printed layer using a dropper, and a cotton swab was placed on top of it. The cotton swab was then moved back and forth 10 times without applying any force (weak). A similar drop was then placed on another location, and the cotton swab was then moved back and forth 10 times with enough force to slightly bend the swab (strong). The degree of dissolution of the printed layer at this time was visually determined and evaluated according to the following criteria. The polyisocyanate compositions (X-2) to (X-7) and (X'-1) to (X'-3) were also evaluated in the same way, and the results are summarized in Tables 2 and 3. ◎: Neither strong nor weak will dissolve 〇: Melts only when strong ×: Both strong and weak dissolve

[0144] [Table 2]

[0145] [Table 3]

[0146] (winding slippage) A winding slippage evaluation was performed in the winding section of a laminating device equipped with a first coating section, a second coating section, a bonding section, and a winding section. In the first coating section, a polyisocyanate composition (X) was applied to the printed surface of a PET film (similar to that used in the evaluation of the resolubility of the printed layer) having a printed layer. In the second coating section, a polyol composition (Y) was applied to a nylon film (Emblem ON, manufactured by Unitika Ltd., film thickness 15 μm). These films were then bonded together so that the polyisocyanate composition (X) and the polyol composition (Y) were in contact with each other in the bonding section. The bonded laminate film was then wound up in the winding section. The winding section was observed to check for the presence or absence of winding slippage, and the results are summarized in a table.

[0147] The mass ratio of the coating amount of the polyisocyanate composition (X) to the polyol composition (Y) is as shown in Tables 4 and 5. The coating amount (g / m 2 ) is the total coating amount of the polyisocyanate composition (X) and the polyol composition (Y). For example, in Example 1, the ratio of the coating amounts of the polyisocyanate composition (X-1) and the polyol composition (Y-1) was 100.0:57.1, and the total coating amount was 2.2 g / m 2 is.

[0148] [Table 4]

[0149] [Table 5]

Claims

1. A two-component curing adhesive comprising: a polyisocyanate composition (X) containing a polyisocyanate compound (A); and a polyol composition (Y) containing a polyol (B) and an amino group-containing compound (C), The polyisocyanate compound (A) includes a polyurethane polyisocyanate (A1) that is a reaction product of a non-aromatic isocyanate derivative having a viscosity of 1500 mPa s or less at 60°C and a polyester polyol, The amino group-containing compound (C) is a two-component curing adhesive containing at least one selected from the group consisting of a polyamine (C1) having a plurality of primary or secondary amino groups and a compound (C2) having a tertiary amino group and a plurality of hydroxyl groups.

2. 2. The two-component curing adhesive according to claim 1, wherein the proportion of the polyurethane polyisocyanate (A1) in the polyisocyanate compound (A) is 15 mass % or more.

3. The two-component curing adhesive according to claim 1 , wherein the polyisocyanate composition (X) contains a diisocyanate monomer in an amount of 1 mass % or less.

4. 2. The two-component curing adhesive according to claim 1, wherein the polyol composition (Y) has an amine value of 1 mgKOH / g or more and 100 mgKOH / g or less.

5. 2. The two-component curing adhesive according to claim 1, wherein the amino group-containing compound (C) comprises a polyamine (C1) having a plurality of primary or secondary amino groups.

6. 2. The two-component curing adhesive according to claim 1, wherein the polyol (B) comprises at least one selected from the group consisting of polyether polyol (B1) and polyester polyol (B2).

7. A laminate comprising a first substrate, a second substrate, and an adhesive layer disposed between the first substrate and the second substrate, wherein the adhesive layer is a cured coating film of the two-component curing adhesive according to any one of claims 1 to 6.

8. A packaging material obtained by forming a bag from the laminate according to claim 7.

Images