Electron beam curable laminate adhesive resin composition

Abstract

To provide a new electron beam curable laminate adhesive resin composition which has excellent adhesive strength in various films, has low elution, enables non-solvent coating, and can reduce GHG emissions during adhesive production and coating.SOLUTION: An adhesive composition contains polyester polyurethane (meth)acrylate (A) having a number average molecular weight of 500 to 2,000, an average number of functional groups of (meth)acryloyl groups of 2.0 or less, and a viscosity of 5,000 cP or less at a shear rate of 200 s-1 measured at 80°C. The polyester polyurethane (meth)acrylate (A) is obtained by reacting polyester polyol (A-1), polyisocyanate (A-2) and hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms, such that 80 mol% or more and less than 200 mol% of the hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms is reacted with respect to the polyester polyol (A-1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an electron beam curable lamination adhesive resin composition, and in particular to an electron beam curable non-solvent lamination adhesive resin composition suitable for use. More specifically, the present invention relates to a non-solvent laminate adhesive resin composition that hardens when irradiated with an electron beam, has high adhesion and low elution properties to metals, plastic films, etc., and can be applied without containing volatile organic solvents, thereby reducing greenhouse gas (GHG) emissions. [Background technology]

[0002] Traditionally, two-liquid urethane thermosetting adhesives with excellent adhesiveness and heat resistance have been used in a wide range of applications, including food packaging, toiletry and industrial packaging, solar cell backsheets, and flexible circuit board sheets. Currently, most thermosetting adhesives, which are the mainstream technology, are synthesized by diluting with a volatile organic solvent during adhesive manufacturing, and then further diluted with a volatile organic solvent to the appropriate viscosity when coating. In addition, a drying process is required after coating to evaporate the volatile organic solvent. This has led to issues such as high GHG emissions during manufacturing and coating. Thermosetting non-solvent adhesives that do not contain volatile organic solvents have low GHG emissions because they do not contain volatile organic solvents, but they have issues such as inferior adhesive performance to thermosetting types that contain volatile organic solvents. UV-curing and electron beam-curing resins, which have been attracting attention in recent years, have a shorter curing time of several seconds than urethane thermosetting adhesives, improving productivity, and also consume less energy than thermosetting types, which is effective in reducing utility costs and GHG emissions. In addition, while urethane thermosetting adhesives have the problem of losing performance when humidity is high, UV-curing and electron beam-curing resins are less affected by humidity, which gives them the advantage of stable performance, and their practical application is progressing. However, compared to urethane thermosetting adhesives, the film strength and adhesiveness are inferior, and there are few examples of non-solvent coating that does not use volatile organic solvents.

[0003] In addition, adhesives for non-solvent coating tend to leave low-molecular reactive monomers behind more easily than adhesives that contain volatile organic solvents as raw materials, and these can leach into the contents through the laminated film. Therefore, from a hygienic standpoint, adhesives that leach fewer chemical substances are required.

[0004] Patent Document 1 discloses an invention relating to an adhesive resin composition in which a polyester polyurethane (meth)acrylate obtained by reacting polyester polyol, polyisocyanate, and hydroxy (meth)acrylate having 5 or more carbon atoms constitutes the basic skeleton of the adhesive resin composition, and when components for imparting various properties to the adhesive, such as an acid anhydride, an epoxy resin having a number average molecular weight of less than 2000, a photocationic initiator, a phosphoric acid-containing (meth)acrylate, and an alkoxysilyl group-containing radical polymerizable compound, are blended with this, the basic properties required of an active energy ray-curable lamination adhesive are maintained and various properties can be imparted. However, no elution test has been investigated, and no disclosure thereof has been made.

[0005] Patent Document 2 discloses an adhesive resin composition comprising an isocyanate group-containing urethane (meth)acrylate obtained by reacting a diol compound, a polyisocyanate compound, and a hydroxyl group-containing (meth)acrylate compound, a compound having an ethylenically unsaturated double bond, and a photopolymerization initiator. However, the photopolymerization initiator generates low molecular weight decomposition products after curing with active energy rays, and is easily eluted into the contents, so there is a problem that the elution property deteriorates when used in large amounts. In addition, aging at room temperature or by heating is required after irradiation with active energy rays, which causes a problem in productivity.

[0006] Patent Document 3 discloses a highly safe urethane acrylate that does not contain any residual toxic substances such as 2-hydroxyethyl acrylate or 3-hydroxypropyl acrylate, and a highly safe energy ray-curable adhesive that contains 1% by weight or more of the urethane acrylate. However, there is no disclosure related to an elution test, and no discussion or disclosure of adhesive performance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6040109 [Patent Document 2] Patent No. 4936111 [Patent Document 3] Patent No. 7166610 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0008] The present invention provides an electron beam-curable non-solvent laminate adhesive resin composition that is cured by irradiation with an electron beam, has high adhesive strength to various films, has low elution properties, and can be applied without solvent, and can reduce GHG emissions during adhesive production and application compared to thermosetting adhesives. [Means for solving the problem]

[0009] As a result of intensive research by the present inventors to solve the above-mentioned problems, it has been found that the polyester polyurethane (meth)acrylate (A) has a structure in which an isocyanate group-containing polyurethane acrylate consisting of a polyisocyanate (A-2) and a hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms is bonded to a polyester polyol (A-1) via a urethane bond, and the polyester polyurethane (meth)acrylate (A) has a number average molecular weight of 500 to 2,000, an average functional group number of (meth)acryloyl groups of 2.0 or less, and a shear rate of 200 s measured at 80° C. -1 The inventors discovered that by controlling the viscosity at 5,000 cP or less, an adhesive can be obtained that has excellent adhesive strength and low elution properties, can be applied without solvent, and can reduce GHG emissions during adhesive production and application, which led to the completion of the present invention.

[0010] Furthermore, the polyester polyurethane (meth)acrylate (A) has a structure in which an isocyanate group-containing polyurethane acrylate consisting of a polyisocyanate (A-2) and a hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms is bonded to a polyester polyol (A-1) via a urethane bond, and is characterized in that (A-3) is bonded to (A-1) at a ratio of 80 mol % or more and less than 200 mol %. This makes it possible to provide an electron beam curable laminating adhesive that has the same adhesive strength and low elution as general packaging laminating adhesives, without having to be polymerized like conventional active energy beam curable resins. In carrying out the present invention, the polyester polyurethane (meth)acrylate (A) may contain 0 to 0.5% by weight of a photoradical polymerization initiator and may have a transmittance of 60% or more at 250 nm in an elution test. The polyester polyurethane (meth)acrylate (A) may also contain a hydroxyl group. Furthermore, the polyisocyanate (A-2) can also be xylylene diisocyanate or isophorone diisocyanate. The electron beam curable laminating adhesive resin composition of the present invention can be used as a non-solvent laminating adhesive. The object to be laminated may be a laminate made of a plastic film or a metal foil. Effect of the Invention

[0011] The present invention makes it possible to provide an electron beam curable non-solvent laminating adhesive that does not contain a volatile organic solvent. Conventional solvent-containing laminating adhesives are synthesized by diluting with a volatile organic solvent during adhesive production. Furthermore, when coating, they are also diluted with a volatile organic solvent to the appropriate viscosity. However, the present invention makes it possible to manufacture and coat without a solvent, which leads to reduction in the dilution process during production, improvement of the effective ingredients during synthesis, and reduction in GHG and costs because the drying process is unnecessary when coating the adhesive. In addition, curing with an electron beam consumes less energy than heat-curing types, which is effective in further reducing GHG. In addition, the adhesive cures in a short time when irradiated with an electron beam, and the time required for curing, which is a drawback of conventional adhesives, can be significantly reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described.

[0013] The electron beam curable non-solvent laminate adhesive resin composition according to the present invention contains a polyester polyurethane (meth)acrylate (A).

[0014] The number of functional (meth)acryloyl groups in the molecule of the polyester polyurethane (meth)acrylate (A) is preferably 2.0 to 0.8, more preferably 1.5 to 0.8. If the number of (meth)acryloyl groups exceeds 2.0, the crosslinking density is high, resulting in weak adhesiveness.

[0015] The number average molecular weight of the polyester polyurethane (meth)acrylate (A) is preferably in the range of 500 to 2,000. When the number average molecular weight is less than 500, the molecular weight between crosslinks is low, resulting in loss of flexibility and weak adhesion. When the number average molecular weight exceeds 2,000, the viscosity is high and the coating suitability is reduced, which is not practical. In addition, the molecular weight between crosslinks is high, resulting in too softness after curing and weak adhesion. The number average molecular weight in the present invention is measured by gel permeation chromatography (GPC).

[0016] The polyester polyurethane (meth)acrylate (A) is obtained by reacting a polyester polyol (A-1), a polyisocyanate (A-2), and a hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms.

[0017] The polyester polyol (A-1) may be, for example, a polybasic acid component such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, or anhydrides thereof, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, HET anhydride, or himic anhydride, used alone or in combination with, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, tripropylene glycol, tetramethyl phthalic acid ... It can be obtained by dehydration condensation of a polyhydric alcohol component, such as ethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, hydrogenated bisphenol A, glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, polyether polyol, polycarbonate diol, acrylic polyol, or polyurethane polyol, either alone or in combination.

[0018] Examples of the polyisocyanate (A-2) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 2,2,4-trimethylsilyl diisocyanate, 2,3,4-trimethylsilyl diisocyanate, 2,4,5-trimethylsilyl diisocyanate, 2,5,6 ... Examples of the polyisocyanate compounds include methylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, and norbornene diisocyanate. Examples of the polyfunctional polyisocyanate compounds include their biuret derivatives, nurate derivatives, and trimethylolpropane adducts. Examples of the isocyanate compounds having a (meth)acryloyl group include 2-isocyanatoethyl (meth)acrylate, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate. These can be used alone or in combination of two or more kinds.

[0019] The hydroxy(meth)acrylate (A-3) has 5 or more carbon atoms. For example, compounds having one (meth)acryloyl group include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 1,5-pentanediol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, polyether-modified hydroxyethyl(meth)acrylate, and caprolactone-modified hydroxyethyl(meth)acrylate. Examples of the compound having two or more acryloyl groups include trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and 2-hydroxy-3-acryloyloxypropyl (meth)acrylate. These can be used alone or in combination of two or more kinds in a ratio of 80 mol % or more and less than 200 mol % based on the polyester polyol (A-1). If it is less than 80 mol% with respect to the polyester polyol (A-1), the adhesive has poor heat resistance, and if it exceeds 200 mol%, the crosslinking density is high, so the adhesiveness is weakened, and a large amount of unreacted hydroxy (meth) acrylate remains, so the elution property is deteriorated. In addition, taking into consideration the reaction rate during synthesis, a compound having a primary hydroxyl group is preferable, and among them, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are particularly preferable.

[0020] The glass transition temperature of the polyester polyurethane (meth)acrylate (A) is not particularly limited, but is preferably −20 to 30° C. If it is lower than −20° C., the heat resistance of the film decreases, and if it exceeds 30° C., the flexibility of the film decreases, leading to a decrease in the laminate strength. The glass transition temperatures can be measured using a rigid pendulum type physical property tester (RPT3000W manufactured by A&D Co., Ltd.).

[0021] In addition, the polyester polyurethane (meth)acrylate (A) may be of two or more different types having different glass transition temperatures. In this case, the glass transition temperature difference is preferably 10 to 30° C. If it is less than 10° C., there is little effect on the film properties, whereas if it exceeds 30° C., there is a risk of poor laminate appearance from the viewpoint of compatibility.

[0022] In carrying out the present invention, the desired properties can be imparted to the electron beam curable non-solvent laminate adhesive resin composition by using an epoxy resin, a silane coupling agent, a phosphate group-containing (meth)acrylate, and a photocationic polymerization initiator.

[0023] The epoxy resin of the present invention is a general term for a resin having an epoxy group in the molecule and an epoxy (meth)acrylate obtained by modifying a resin having an epoxy group in the molecule and imparting a (meth)acryloyl group in the molecule. Resins having epoxy groups are preferably those having excellent heat resistance, and examples thereof include bisphenol A type epoxy resins, bisphenol F type epoxy resins, alicyclic epoxy resins, novolac type epoxy resins, and epoxy acrylates. For example, bisphenol A type epoxy resins include those manufactured by Mitsubishi Chemical Corporation (jER825, jER827, jER828, jER1001, jER1002, jER1003, jER1004, jER1032H60), bisphenol F type epoxy resins include those manufactured by Mitsubishi Chemical Corporation (jER4004P, jER4005P), alicyclic epoxy resins include those manufactured by Daicel Corporation (Celloxide 2021P, Celloxide 2081, Epolead GT401), novolac type epoxy resins include those manufactured by DIC Corporation (EPICLON N-660, EPICLON N-740), and epoxy acrylates include those manufactured by Daicel-Allnex Corporation (EBECRYL600, EBECRYL3603, EBECRYL3700). These can be used alone or in combination of two or more kinds. The blending ratio is preferably 0.1 to 10% by weight based on the total amount. If it is less than 0.1%, there is little effect on the film properties, but if it is blended in excess of 10% by weight, the adhesiveness becomes weak.

[0024] The silane coupling agent of the present invention is effective in improving adhesion to metal-based materials such as metal foils and vapor-deposited films. For example, vinyltrimethoxysilane, vinyltributoxysilane, allyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, p-styryltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-(2-(aminoethylamino)propyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltri ... Examples of the ethoxy derivatives include dimethoxymethylsilane, N-ethyl-4-amino-3,3-dimethylbutyldimethoxymethylsilane, N-ethyl-4-amino-3,3-dimethylbutyltrimethoxysilane, N-butyl-3-amino-2-methylpropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and ethoxy derivatives thereof. These may be used alone or in combination with two or more of them, such as organosiloxanes obtained by condensing two or more of them. The blending ratio is preferably 0.1 to 5% by weight based on the total amount. If it is less than 0.1%, the film properties are not significantly affected, and if it is blended in excess of 5% by weight, the adhesion and heat resistance are weakened.

[0025] The phosphoric acid group-containing (meth)acrylate of the present invention is particularly effective in improving adhesion to metal-based materials such as metal foils. The compounding ratio is preferably 0.1 to 5% by weight based on the total amount. If it is less than 0.1%, the film properties are not significantly affected, and if it is compounded in excess of 5% by weight, the adhesiveness and heat resistance are weakened. Phosphorus compounds not containing (meth)acryloyl groups can be used alone or in combination of two or more kinds, but phosphoric acid group-containing (meth)acrylates that participate in crosslinking reactions are more preferred because they provide excellent adhesiveness and durability. Examples of phosphoric acid group-containing (meth)acrylates include 2-(meth)acryloyloxyethyl acid phosphate and bis(2-(meth)acryloyloxyethyl)-acid phosphate, such as those manufactured by Kyoeisha Chemical Co., Ltd. (Light Ester P-1M, Light Ester P-2M, Light Acrylate P-1A) and BASF (Laromer PA9083), and can be used alone or in combination of two or more kinds.

[0026] The photocationic polymerization initiator of the present invention is used as a cationic polymerization initiator for the epoxy resin and the alkoxysilyl group-containing radical polymerizable compound. Examples of the photocationic polymerization initiator include onium salts such as ionic aromatic sulfonium salts and aromatic iodonium salts consisting of a cationic part and an anionic part, and are, for example, those manufactured by IGM Resins BV (Omnicat 250, Omnicat 270), ADEKA Corporation (ADEKA Optomer SP series), and San-Apro Co., Ltd. (CPI-100P, CPI-101A). The blending ratio is preferably 0.1 to 5% by weight based on the total amount from the viewpoint of reactivity. If it is less than 0.1% by weight, the curing is insufficient and the peel strength and heat resistance are reduced, and if it is blended in excess of 5% by weight, the elution property is deteriorated and the adhesion property is reduced.

[0027] If necessary, the adhesive resin composition of the present invention may contain a polyisocyanate or an isocyanate compound having a radically polymerizable unsaturated bond within a range that does not impair the desire for a short aging time. The reaction between the hydroxyl groups of the cured adhesive and the moisture in the base material and the isocyanate groups increases the cohesive strength and improves the adhesive strength. The amount of the additive is preferably less than 20% by weight, since if it is mixed in an amount of 20% by weight or more, the short aging effect may be significantly impaired or the reaction of moisture and isocyanate with carbon dioxide gas may cause bubbles in the adhesive layer.

[0028] If necessary, various additives such as tackifiers, reaction accelerators, leveling agents, ultraviolet absorbers, and defoamers, as well as coloring pigments and extender pigments, can be added to the adhesive resin composition of the present invention within a range that does not impair the performance of the composition.

[0029] Examples of the tackifier include paraffin wax, polyethylene wax, rosin, rosin glycerin ester, terpene, and alkylphenol. One or more types selected from this group can be used.

[0030] Examples of the reaction accelerator include metal catalysts such as dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, dibutyltin dimaleate, tetrabutyl titanate, and tetraisopropyl titanate; tertiary amines such as 1,8-diaza-bicyclo(5,4,0)-7-undecene, 1,5-diazabicyclo(4,3,0)-5-nonene, and 6-dibutylamino-1,8-diazabicyclo(5,4,0)-7-undecene; and reactive tertiary amines such as triethanolamine. One or more types selected from this group can be used.

[0031] Examples of leveling agents include acrylic polymers, modified silicones, and acetylene diols. Examples of ultraviolet absorbers include benzotriazoles, hydroxyphenyltriazines, and hindered amines. Examples of defoamers include organic polyethers and surfactants, and inorganic silicone compounds. One or more types selected from these groups can be used.

[0032] Examples of coloring pigments include organic pigments such as anthraquinone, diketopyrrolopyrrole, perylene maroon, carbon black, dioxazine, perylene, benzimidazolone, isoindolinone, isoindoline, phthalocyanine, and indanthrene, and inorganic pigments such as yellow iron oxide, red iron oxide, azomethine copper complex, titanium oxide, and silicon oxide. Examples of extender pigments include inorganic pigments such as barium sulfate, calcium carbonate, barium sulfate, barium carbonate, calcium carbonate, magnesium oxide, magnesium carbonate, magnesium hydroxide, barium titanate, calcium hydroxide, calcium sulfite, calcium sulfate, calcium oxide, calcium silicate, silica, zeolite, and talc. One or more types selected from these groups can be used.

[0033] The adhesive resin composition of the present invention is instantly cured by irradiation with an electron beam, but in order to improve the curing property, a photoradical polymerization initiator may be added in an amount of 0 to 0.5% by weight based on the total amount, as long as the performance is not impaired. If the content exceeds 0.5% by weight, low molecular weight decomposition products are generated after curing with active energy rays, and dissolve into the contents, resulting in poor dissolution property. Photoradical polymerization initiators include benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one, phenylglyoxylic acid methyl ester, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane- 1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 1,2-octanedione, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), and the like, which may be used alone or in combination of two or more.

[0034] The adhesive resin composition of the present invention can use a radically polymerizable reactive diluent to adjust the viscosity according to the coating method and the specifications of the coater, within a range that does not impair the performance. Examples of reactive diluents include monofunctional (meth)acrylates such as 4-t-butylcyclohexanol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, stearyl (meth)acrylate, diethylene glycol monobutyl ether (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, isobornyl (meth)acrylate, myristyl (meth)acrylate, and 4-(meth)acryloylmorpholine; 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, and 1,5-butylene glycol diacrylate; Examples of such acrylates include bifunctional (meth)acrylates such as hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; and polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and propoxylated glyceryl tri(meth)acrylate. These may be used alone or in combination of two or more.

[0035] The adhesive resin composition of the present invention may be laminated by a conventional method, and a coating method using a non-solvent coater is particularly suitable, but dry lamination coating in which the composition is diluted with a solvent is also possible. As the dilution solvent, the composition may be diluted with a solvent such as hydrocarbons, acetates, ketones, or alcohols, and from the viewpoint of coating workability, ethyl acetate or methyl ethyl ketone is preferred. The coating amount is 0.8 to 4.0 g / m2 on a dry basis. 2 This range is preferable from the viewpoint of the appearance of the laminate, but may be determined according to the type of film and the required performance.

[0036] The laminable film according to the present invention is not particularly limited, and can be used when laminating films having the same or different adhesive surfaces selected from plastic materials, metal materials, and inorganic materials. More specifically, plastic films such as polyethylene terephthalate, polyamides such as nylon, polyethylene, and polypropylene, barrier films with aluminum, silica, alumina, and the like vapor-deposited, organic barrier films such as polyvinyl alcohol films, polyvinylidene chloride films, and ethylene-vinyl alcohol copolymer films, and metal films such as aluminum foil, copper foil, and stainless steel foil can be used when bonding these various films together. In particular, from the viewpoint of recycling, films that constitute a laminate in which the same material is 90% or more, and more preferably 95% or more, are preferred, and examples thereof include lamination of a biaxially oriented polypropylene film with a non-oriented polypropylene film, a polyethylene terephthalate film, and a heat-sealable polyethylene terephthalate film.

[0037] (Dissolution test) The electron beam curable non-solvent laminating adhesive of the present invention was applied to the ALM side of the PET / ALM film using a solventless laminator at a coating roll temperature of 80°C, a processing speed of 10 m / min, and a coating amount of 3.5 g / m 2 After laminating a non-oriented polypropylene (CPP) film (thickness: 100 μm) onto this coated surface, it was irradiated with an electron beam of 50 kGy and 150 kV to obtain a laminate film. The laminate film was cut to a size of 160 mm x 60 mm, folded so that the non-oriented polypropylene (CPP) film was on the inside, and heat-sealed in three directions to a width of 5 mm to create a pouch. The contents were 10 ml of distilled water. The filled pouch was sterilized in a retort tester at 121°C for 30 minutes, after which the distilled water was removed and placed in a 10 mm x 10 mm quartz cell, and measured with a UV-Vis-NIR spectrophotometer (Shimadzu Corporation), and the following evaluations were performed. 〇: Transmittance of 250 nm is 60% or more. Pass ×: Transmittance at 250 nm is less than 60%. Fail EXAMPLES

[0038] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

[0039] (Synthesis Example of Polyester Polyol (A-1)-(I)) In a flask equipped with a nitrogen inlet tube, a stirrer, a distillation column, and a condenser, neopentyl glycol (140 g), 1,6-hexanediol (205 g), ethylene glycol (80 g), isophthalic acid (410 g), sebacic acid (150 g), and adipic acid (15 g) were added, and dehydration condensation was performed at an internal temperature of 180 to 200 ° C. while stirring. After confirming that the resin acid value became 15 mg KOH / g, the dehydration reaction was further promoted at 200 to 240 ° C. while performing nitrogen bubbling. After that, it was confirmed that the resin acid value became 1 mg KOH / g or less, and a polyester polyol (A-1)- (I) with a number average molecular weight = 1,000, a functional number of hydroxyl groups of 2.0, and a hydroxyl value = 112 mg KOH / g was obtained.

[0040] (Synthesis Example of Polyester Polyol (A-1)-(II)) In a flask equipped with a nitrogen inlet tube, a stirrer, a distillation column, and a condenser, neopentyl glycol (140 g), 1,6-hexanediol (300 g), ethylene glycol (50 g), isophthalic acid (300 g), sebacic acid (150 g), and adipic acid (60 g) were added, and dehydration condensation was performed at an internal temperature of 180 to 200 ° C. while stirring. After confirming that the resin acid value became 15 mg KOH / g, the dehydration reaction was further promoted at 200 to 240 ° C. while performing nitrogen bubbling. After that, it was confirmed that the resin acid value became 1 mg KOH / g or less, and a polyester polyol (A-1)- (II) with a number average molecular weight = 500, a functional number of hydroxyl groups of 2.0, and a hydroxyl value = 224 mg KOH / g was obtained.

[0041] (Synthesis Example of Polyester Polyol (A-1)-(III)) In a flask equipped with a nitrogen inlet tube, a stirrer, a distillation column, and a condenser, neopentyl glycol (400 g), 1,6-hexanediol (190 g), ethylene glycol (80 g), isophthalic acid (400 g), sebacic acid (40 g), and adipic acid (140 g) were added, and dehydration condensation was performed at an internal temperature of 180 to 200 ° C. while stirring. After confirming that the resin acid value became 15 mg KOH / g, the dehydration reaction was further promoted at 200 to 240 ° C. while performing nitrogen bubbling. After that, it was confirmed that the resin acid value became 1 mg KOH / g or less, and a polyester polyol (A-1)- (III) with a number average molecular weight of 1,500, a functional number of hydroxyl groups of 2.0, and a hydroxyl value of 75 mg KOH / g was obtained.

[0042] (Synthesis Example of Polyester Polyol (A-1)-(IV)) In a flask equipped with a nitrogen inlet tube, a stirrer, a distillation column, and a condenser, neopentyl glycol (160 g), 1,6-hexanediol (200 g), trimethylolpropane (20 g), ethylene glycol (80 g), isophthalic acid (350 g), sebacic acid (90 g), and adipic acid (100 g) were added, and dehydration condensation was performed at an internal temperature of 180 to 200 ° C. while stirring. After confirming that the resin acid value became 15 mg KOH / g, the dehydration reaction was further promoted at 200 to 240 ° C. while performing nitrogen bubbling. After that, it was confirmed that the resin acid value became 1 mg KOH / g or less, and a polyester polyol (A-1)- (IV) with a number average molecular weight = 1,000, a functional number of hydroxyl groups of 3.0, and a hydroxyl value = 168 mg KOH / g was obtained.

[0043] (Example 1-1. Synthesis Example of Polyester Polyurethane (Meth)acrylate (A)) Xylylene diisocyanate (A-2) (100 mol) and 2-hydroxyethyl acrylate (A-3) (100 mol) were added to a flask equipped with a nitrogen inlet tube, a stirrer, and a condenser, and the mixture was reacted at 55-60°C for 3 hours under a nitrogen stream to obtain a urethane prepolymer. Polyester polyol (A-1)-(I) (100 mol) was added to the obtained urethane prepolymer, and the reaction was allowed to proceed at 75-80°C. The reaction was allowed to proceed, and the synthesis was terminated when it was confirmed that the absorption of the isocyanate group had completely disappeared in the infrared absorption spectrum. Number average molecular weight = 1,300, average number of acryloyl groups = 1, and shear rate measured at 80°C was 200 s -1 Thus, a polyester polyurethane acrylate (A) (1-1) having a viscosity of 3,200 cP was obtained.

[0044] Examples 1-2 to 1-6 and Comparative Examples 2-1 to 2-4 were synthesized in the composition ratios shown in Table 1 in the same manner as in Example 1-1.

[0045] (Preparation of Laminate Film) The adhesives of the Examples and Comparative Examples shown in Table 1 were applied to a PET film (thickness: 12 μm) using a solventless laminator at a coating roll temperature of 80° C., a processing speed of 10 m / min, and a coating amount of 3.5 g / m 2 The coating was performed under the following conditions. A linear low-density polyethylene (LLDPE) film (thickness: 50 μm) was laminated onto the coated surface. After that, the film was irradiated with electron beams of 50 kGy and 150 kV using an electron beam irradiation device (manufactured by Iwasaki Electric Co., Ltd.) to obtain a laminate film.

[0046] (peel strength) The laminate film was cut to a width of 15 mm, and the T-peel strength was measured at a pulling speed of 50 mm / min using a tensile tester (EZ Test, manufactured by Shimadzu Corporation), and each was evaluated as follows. ○:3N or more passed ×: Less than 3N, fail

[0047] (Dissolution test) The adhesives of the Examples and Comparative Examples shown in Table 1 were applied to the ALM side of the PET / ALM film using a solventless laminator at a coating roll temperature of 80°C, a processing speed of 10 m / min, and a coating amount of 3.5 g / m 2 The coating was performed under the following conditions. A non-oriented polypropylene (CPP) film (thickness: 100 μm) was laminated onto the coated surface. After that, the film was irradiated with an electron beam to obtain a laminate film. The laminate film was cut to a size of 160 mm x 60 mm, folded so that the non-oriented polypropylene (CPP) film was on the inside, and heat-sealed in three directions to a width of 5 mm to create a pouch. The contents were 10 ml of distilled water. The filled pouch was sterilized in a retort tester at 121°C for 30 minutes, after which the distilled water was removed and placed in a 10 mm x 10 mm quartz cell, and measured with a UV-Vis-NIR spectrophotometer (Shimadzu Corporation), and the following evaluations were performed. 〇: Transmittance of 250 nm is 60% or more. Pass ×: Transmittance at 250 nm is less than 60%. Fail

[0048] The results in Table 1 confirm that the electron beam-curable non-solvent laminate adhesives of Examples 1-1 to 1-6 provided excellent results in terms of peel strength, elution properties, and coatability. In Comparative Example 2-1, the average number of functional groups exceeded 2, so sufficient peel strength was not obtained. In Comparative Example 2-2, the viscosity exceeded 5,000 cP, so sufficient coating suitability was not obtained. In Comparative Example 2-3, the photopolymerization initiator was contained in an amount exceeding 0.5 wt%, so the elution test was not passed. In Comparative Example 2-4, the hydroxy(meth)acrylate (A-3) having 5 or more carbon atoms was contained in an amount less than 80 mol%, so the peel strength and elution tests were not passed.

[0049] [Table 1]

Claims

1. The number average molecular weight is 500 to 2,000, the average number of (meth)acryloyl groups is 2.0 or less, and the shear rate measured at 80°C is 200 s －１ The electron beam curable adhesive resin composition for lamination comprises a polyester polyurethane (meth)acrylate (A) having a viscosity of 5,000 cP or less at 200 mol%, wherein the polyester polyurethane (meth)acrylate (A) has a structure in which an isocyanate group-containing polyurethane acrylate composed of a polyisocyanate (A-2) and a hydroxy (meth)acrylate (A-3) having 5 or more carbon atoms is bonded to a polyester polyol (A-1) via a urethane bond, and the bond ratio of (A-3) to (A-1) is 80 mol % or more and less than 200 mol %.

2. The electron beam curable adhesive resin composition for lamination according to claim 1, characterized in that it contains 0 to 0.5% by weight of a photoradical polymerization initiator relative to the polyester polyurethane (meth)acrylate (A), and has a transmittance of 60% or more at 250 nm in an elution test.

3. 3. The electron beam curable adhesive resin composition for lamination according to claim 1, wherein the polyester polyurethane (meth)acrylate (A) contains a hydroxyl group.

4. 3. The electron beam curable adhesive resin composition for lamination according to claim 1, wherein the polyisocyanate (A-2) contains at least one selected from the group consisting of xylylene diisocyanate and isophorone diisocyanate.

5. 3. The electron beam curable adhesive resin composition for lamination according to claim 1, which is used as a non-solvent adhesive for laminating laminates containing plastic films or metal foils.

6. A laminate obtained by laminating materials using the electron beam curable laminating adhesive resin composition according to claim 5.

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