JP2004230749A - Manufacturing method of laminate film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a favorably tearable laminate film (having easily tearing properties) excellent in adhesion. <P>SOLUTION: In the manufacturing method of the laminate film for pasting a heat fusible plastic film to a plastic film with an inorganic layer formed thereon applied by a laminate adhesive prepared by blending a hydroxy group-terminated polyurethane resin (A) with a polyisocyanate curing agent (B) under the mass ratio of (A):(B)=100:30 to 100:100 and then thermally curing them, (A) has a substantial average functionality of 2 and a number average molecular weight of 10,000-50,000 and (B) is an isocyanurate-modified polyisocyanate of hexamethylenediisocyanate having a substantial average functionality of 2-10. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４７】
【表２】

【００４８】
【表３】

【００４９】
【表４】

【００５０】
表２、４から、ポリイソシアネート硬化剤配合比が少なすぎる場合（比較例１、２、７、８）は、無機質面と接着剤の接着性が不十分なため、無機質面と接着剤の間で界面破壊が起き、そのため引き裂き時に泣き別れが生じたものと思われる。ポリイソシアネート硬化剤配合比が多すぎる場合（比較例５、６、１１、１２）は、ポリイソシアネート分子の架橋が効率的でないため、接着剤層の強度が低下し、引き裂き時に泣き別れが生じたものと思われる。また主剤が分岐タイプである比較例３、４、９、１０は、主剤の分子量が小さいため、架橋点間の分子のフレキシビリティがなくなり、接着性が低下している。その一方、ポリイソシアネート硬化剤配合比が適当である実施例は、主剤や硬化剤の種類に関わりなく、接着性、ヒートシール性、引き裂き性とも良好な結果であった。
【００５１】
【発明の効果】
以上説明した通り、本発明により接着性・引き裂き性に優れたラミネートフィルムが容易に得ることができる。[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for producing a laminate film which can be easily opened using a plastic film having an inorganic layer formed on the plastic film. More specifically, the present invention relates to a method for producing a laminated film which is required to be airtight when packaging foods, pharmaceuticals, chemicals, medical equipment, electronic components, and the like, and is required to be easily opened when taking out the contents. is there.
[0002]
[Prior art]
BACKGROUND ART Conventionally, various packaging materials having a barrier property against oxygen gas, water vapor and the like and having good storage suitability have been developed. For example, as a film having excellent gas barrier properties, a film in which aluminum is laminated on a plastic film (Patent Document 1), a film in which vinylidene chloride or an ethylene-vinyl alcohol copolymer is coated, or a thin film such as silicon oxide is laminated. (Patent Literature 2) is known. In recent years, an inorganic vapor-deposited film having a structure in which a vapor-deposited film of an inorganic oxide such as silicon oxide or aluminum oxide is formed on a flexible plastic substrate, a packaging laminate and a packaging container using the same. (Patent Document 3) has been proposed. In particular, silicon oxide, an inorganic vapor-deposited film on which a vapor-deposited film of an inorganic oxide such as aluminum oxide is formed, compared with a conventional aluminum foil, a laminate material for packaging using a polyvinylidene chloride-based resin-coated nylon film, or the like. It has excellent transparency, high barrier properties against water vapor, oxygen gas, etc., and fragrance retention. Furthermore, there is no environmental problem at the time of disposal, and the demand for packaging materials and the like is greatly expected. Is what it is.
[0003]
[Patent Document 1]
JP-A-62-101428 [Patent Document 2]
Japanese Patent Publication No. 51-48511 [Patent Document 3]
Patent No. 3070702 [0004]
However, when an inorganic vapor-deposited film as described above is subjected to extrusion coating or dry lamination to produce a packaging laminate, the adhesive strength of the inorganic vapor-deposited film and the conventional laminating adhesive, anchor coating agent, etc., is not sufficient. There is a problem that it is low. And often, in a packaging bag made of such a laminated material, when trying to open the packaging bag in order to take out the contents, due to a decrease in lamination strength, a part of the film of the packaging bag is stretched and is difficult to tear. In some cases, the contents may jump out of the packaging bag at once and scatter.
[0005]
In order to improve the above laminating strength etc., pre-treatment such as corona treatment may be performed, but the effect is not so much recognized in the inorganic vapor-deposited film, and on the contrary, there is a problem that the vapor-deposited layer is damaged. is there. Further, as another method, a method of forming a coating composition of a primer composition containing a silane coupling agent or a polyester-based resin composition on an inorganic vapor-deposited thin film and then bonding them with a laminating adhesive has also been proposed. However, there is a problem that at least four layers are formed of the inorganic vapor deposited film / coating film / adhesive / heat-sealing resin, which leads to an increase in cost compared to a three-layer laminated material.
[0006]
In order to solve the above-mentioned problem, Patent Document 4 proposes an inorganic vapor-deposited film adhesive containing a polyurethane resin having a branch point in a molecule and an amine-based silane coupling agent.
[0007]
[Patent Document 4]
JP 2002-27547 A
However, in the adhesive of Patent Document 4, the molecular weight of the polyurethane resin as the main component must be about several thousands due to manufacturing restrictions. When the main agent alone is used, the adhesive strength becomes insufficient, and when a polyisocyanate curing agent is used, the molecular weight between cross-linking points is too small, so that flexibility may be lacking.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a laminated film which solves the above-mentioned problems and has excellent adhesion and tears easily (easy tearing).
[0010]
That is, the present invention provides a laminate adhesive in which a hydroxyl group-terminated polyurethane resin (A) and a polyisocyanate curing agent (B) are blended at a mass ratio of (A) :( B) = 100: 30 to 100: 100, In a method for producing a laminate film, which is applied to a plastic film having an inorganic layer formed thereon, and a heat-fusible plastic film is attached and cured by heating.
(A) the isocyanurate-modified poly (hexamethylene diisocyanate) having a substantial average number of functional groups of 2, a number average molecular weight of 10,000 to 50,000, and (B) a substantial average number of functional groups of 2 to 10; A method for producing a laminate film, characterized by being an isocyanate.
[0011]
Further, the present invention is the above-mentioned method for producing a laminated film, wherein an amount of the laminated adhesive applied to the plastic film on which the inorganic layer is formed is 1 to 10 g / m ² in a dry state.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The polyurethane resin (A) as a main component used in the present invention is a hydroxyl group terminal, has a substantially average number of functional groups of 2, and a number average molecular weight of 10,000 to 50,000, and preferably has a substantially average number of functional groups. 2. The number average molecular weight is from 15,000 to 30,000. When the substantial number of functional groups is less than 2, adhesive strength is insufficient due to insufficient crosslinking. On the other hand, if it exceeds 2, it becomes difficult to make the number average molecular weight exceed 10,000 in the production of polyurethane resin, and such polyurethane resin tends to have insufficient adhesiveness. When the number average molecular weight is less than 10,000, the crosslinking density becomes too high, and the flexibility tends to be insufficient. If it exceeds 50,000, the viscosity at the time of applying the adhesive becomes too high, and the productivity decreases. Here, “substantially average number of functional groups is 2” means that the average number of functional groups of all raw materials constituting the polyurethane resin is substantially 2 and the purity of the terminal group is 2 or more. This is a concept that does not necessarily need to be 100%.
[0013]
The polyurethane resin (A) used in the present invention is obtained by reacting a polymer polyol, an organic diisocyanate and, if necessary, a chain extender.
[0014]
Examples of the polymer polyol include a polyester polyol, a polyesteramide polyol, a polycarbonate polyol, a polyether polyol, a polyolefin polyol, an animal and plant-based polyol, and a copolyol thereof. These polymer polyols may be used alone or in combination of two or more. In the present invention, polyester polyol is preferred in consideration of adhesiveness, heat resistance, and the like. The number average molecular weight of the high molecular polyol is preferably from 300 to 10,000, particularly preferably from 500 to 5,000.
[0015]
Known polyester polyols and polyester amide polyols include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, and naphthalenedicarboxylic acid. One or more dicarboxylic acids, acid esters, or acid anhydrides and the like, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5 -Pentanediol, neopentyl glycol, 1,8-octa Diol, 1,9-nonanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1,3 -Pentanediol, 2-ethyl-1,3-hexanediol, 2-n-hexadecane-1,2-ethylene glycol, 2-n-eicosan-1,2-ethylene glycol, 2-n-octacosan-1,2 -Ethylene glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, or an ethylene oxide or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy- Low molecular diols such as 2,2-dimethylpropionate; Those obtained by the dehydration condensation reaction of above. Lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using a low molecular weight diol as an initiator are also exemplified.
[0016]
Examples of the polycarbonate polyol include those obtained by a dealcoholation reaction, a dephenolization reaction, or the like of a low-molecular-weight polyol used in the synthesis of the above-mentioned polyester polyol and diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or the like.
[0017]
As the polyether polyol, low-molecular diols used in the above-mentioned polyester polyol, alkylamines, polyethylene glycol, polypropylene obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc., using a primary monoamine such as aniline as an initiator. Glycol, polytetramethylene ether glycol, and the like, and a polyether polyol obtained by copolymerizing these, and a polyester ether polyol using the above-described polyester polyol or polycarbonate polyol as an initiator are exemplified.
[0018]
Examples of the polyolefin polyol include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene.
[0019]
Animal and plant-based polyols include castor oil-based polyols and silk fibroin.
[0020]
The urea resin, melamine resin, epoxy resin, polyester resin, acrylic resin, polyvinyl alcohol, rosin resin and the like are generally known in the polyurethane industry, and have one functional group capable of reacting with an isocyanate group such as an active hydrogen group. As long as it preferably contains two or more, it can be used as all or a part of the active hydrogen group-containing compound.
[0021]
Examples of the organic diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3-diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4. '-Diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4, 4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate Aromatic diisocyanates such as 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate and lysine diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, Examples include diisocyanates such as alicyclic diisocyanates such as hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and tetramethyl xylene diisocyanate. One or more of these can be used.
[0022]
In the present invention, a chain extender may be used for the purpose of adjusting the (number average) molecular weight of the polyurethane resin and the distribution of hard segments and soft segments. Examples of the chain extender include low-molecular-weight polyols which are raw materials for the polyester polyol, dimethylolalkanoic acids such as dimethylolpropionic acid and dimethylolbutanoic acid, ethylenediamine, hexamethylenediamine, isophoronediamine, (hydrogenated) diphenylmethanediamine And low-molecular-weight amino alcohols such as monoethanolamine, water, and urea.
[0023]
As a reaction apparatus for producing the polyurethane resin (A), any apparatus can be used as long as the above-mentioned reaction can be achieved. For example, a mixing and kneading apparatus such as a reaction vessel equipped with a stirrer, a kneader, a single-screw or multi-screw extrusion reactor, and the like. Is mentioned. In order to accelerate the reaction, a metal catalyst such as dibutyltin dilaurate or a tertiary amine catalyst such as triethylamine which is commonly used in the production of polyurethane or polyurea can be used as a catalyst.
[0024]
The form of the polyurethane resin (A) is used in a non-aqueous type, that is, a non-solvent state or a solution state of an organic solvent. Preferred in the present invention is a solution state of an organic solvent. An adhesive using a water-based polyurethane resin is not preferred in terms of poor wettability to a substrate at the time of applying the adhesive, and a large amount of heat energy required at the time of drying the adhesive.
[0025]
In the present invention, a preferable organic solvent is not particularly limited as long as it is inert to an isocyanate group, and examples thereof include aromatic hydrocarbon solvents such as toluene and xylene, and ethyl acetate and butyl acetate. Solvents, ketone solvents such as methyl ethyl ketone and cyclohexanone, glycol ether ester solvents such as ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, and ethyl-3-ethoxypropionate; ether solvents such as tetrahydrofuran and dioxane; dimethylformamide Using one or more polar solvents such as dimethylacetamide, N-methylpyrrolidone, furfural, etc., preferably at 100 ° C. or lower, and uniformly mixing and reacting the respective components within the above-mentioned mixing condition range. Do Door can be. It is preferable that the solid content finally becomes 20 to 80% by mass.
[0026]
If necessary, the polyurethane resin composition (A) may contain a pigment, a dye, a solvent, a thixotropic agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersant, a surfactant, and a fungicide. Additives such as agents, antibacterial agents, preservatives, catalysts, and fillers can be added.
[0027]
The polyisocyanate curing agent (B) used in the present invention is an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate. (B) has a substantial average number of functional groups of 2 to 10, preferably 2.5 to 8. Further, the isocyanate content of (B) is preferably from 15 to 25% by mass, particularly preferably from 17 to 23% by mass. Further, the number average molecular weight of (B) is preferably from 300 to 5,000, particularly preferably from 500 to 3,000.
[0028]
Incidentally, if necessary, a polyisocyanate other than the above (B) can be used in combination. Examples of the polyisocyanate other than (B) include urethane-modified, allophanate-modified, urea-modified, biuret-modified, carbodiimide-modified, and uretonimine of organic diisocyanates such as diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Modified form, uretdione modified form, isocyanurate modified form and the like can be mentioned.
[0029]
In the present invention, in the laminate adhesive, the mass blending ratio of the polyurethane resin (A) as the main component and the polyisocyanate curing agent (B) is a solid content conversion ratio, and (A) :( B) = 100: 30 to 100: 100, preferably (A) :( B) = 100: 40 to 100: 100. If the amount of the curing agent is too small, the tearability is reduced. If the amount of the curing agent is too large, the crosslink density decreases and the adhesive strength decreases.
[0030]
Examples of the plastic film in the “plastic film on which an inorganic layer is formed” used in the present invention include expanded polypropylene (OPP), undrawn polypropylene (CPP), polyester (PET), nylon (NY), and low-density polyethylene (LLDPE). High density polyethylene (HDPE), ethylene-vinyl acetate copolymer (EVA), polypinyl alcohol (PVA), ethylene vinyl alcohol copolymer (EVOH), polystyrene (PS), polycarbonate (PC), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC) and the like.
[0031]
Examples of the inorganic substance constituting the inorganic layer include metal aluminum, silicon oxide, aluminum oxide, silicon oxide-aluminum oxide, and the like, and inorganic oxides such as silicon oxide, aluminum oxide, and silicon oxide-aluminum oxide are suitable for the inorganic layer. Used for Examples of the forming method include vapor deposition and coating.
[0032]
The heat-fusible plastic film used in the present invention becomes an inner surface when the obtained laminated film is formed into a bag, and is required to have heat sealability. Specifically, CPP, LLDPE, ethylene-vinyl acetate copolymer, ionomer, polyvinyl chloride, polyvinylidene chloride, polyurethane, fluororesin, polyacrylonitrile, polystyrene, polyethylene terephthalate, maleic acid-modified polyolefin, ethylene-acrylic acid copolymer Copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer and the like. The thickness of the heat-fusible plastic film is preferably about 5 μm to 500 μm, particularly preferably 30 μm to 100 μm. When the thickness is less than 5 μm, the adhesive strength when heat-fusible plastic films are melted by heat is remarkably reduced. When the thickness exceeds 500 μm, the flexibility of the film is unfavorably deteriorated. Prior to lamination, the surface (that is, the adhesive surface) of the heat-fusible plastic film may be subjected to an easy adhesion treatment such as a corona treatment, a plasma treatment, and a frame treatment.
[0033]
The specific manufacturing procedure of the laminate film of the present invention is to apply an adhesive to the vapor-deposited surface of the inorganic layer plastic film by a dry laminator, and after evaporating the solvent, the other laminate substrate such as a heat-fusible plastic film. Lamination and then aging at 20-70 ° C. for 10-120 hours, preferably at 25-50 ° C. for 20-100 hours, to complete the curing reaction. The adhesive application amount is 1 to 10 g / m ² . The bonding condition is preferably 0.1 to 1 MPa at 30 to 180 ° C, and particularly preferably 0.2 to 0.8 MPa at 50 to 150 ° C. By such a method, not only a film in which two films are laminated but also a film in which three or more films are laminated can be manufactured. A so-called primer may be used before the application of the adhesive. However, the adhesive of the present invention has a sufficient adhesion performance without using a primer, and the use of a primer is not preferable because the cost increases.
[0034]
【Example】
Next, examples of the present invention will be described in detail, but the present invention is not construed as being limited by these examples. Unless otherwise specified, “%” in Examples and Comparative Examples means “% by mass”, and all number average amounts are based on GPC.
[0035]
(Production of polyurethane resin solution for main agent)
Production Example 1
914.3 g of polyol A, 10.4 g of DMBA, and 667 g of ethyl acetate were charged into a 2 L reactor equipped with a stirrer, a thermometer, a nitrogen seal tube, and a cooler, and dissolved at 60 ° C. Next, 75.3 g of HDI and 0.2 g of DOTDL were charged and reacted at 70 ° C. for 4 hours. When the absorption peak of the isocyanate group disappeared in the infrared absorption analysis, 333 g of ethyl acetate was further added and diluted to obtain a polyurethane resin solution PU-1. The solid content of PU-1 was 50%, the viscosity at 25 ° C was 2,100 mPa · s, and the number average molecular weight was 20,000.
[0036]
Production Example 2
790.6 g of polyol A, 104.4 g of polyol B, 8.4 g of DMBA, and 300 g of ethyl acetate were charged into a 2 L reactor having the same capacity as in Production Example 1, and dissolved at 60 ° C. Next, 96.6 g of IPDI and 0.2 g of DOTDL were charged and reacted at 70 ° C. for 4 hours. When the absorption peak of the isocyanate group disappeared in the infrared absorption analysis, 500 g of ethyl acetate was further added and diluted to obtain a polyurethane resin solution PU-2. The solid content of PU-2 was 60%, the viscosity at 25 ° C was 2,500 mPa · s, and the number average molecular weight was 20,000.
[0037]
Production Example 3
In a 2 L reactor having the same capacity as in Production Example 1, 521.7 g of polyol C, 521.7 g of polyol D, and 26.2 g of TMP were charged with 300 g of ethyl acetate, and dissolved at 60 ° C. Next, 130.4 g of IPDI and 0.2 g of DOTDL were charged and reacted at 70 ° C. for 4 hours. When the absorption peak of the isocyanate group disappeared in the infrared absorption analysis, 500 g of ethyl acetate was further added for dilution to obtain a polyurethane resin solution PU-3. The solid content of PU-3 was 60%, the viscosity at 25 ° C was 500 mPa · s, the number average molecular weight was 6,000, and the branch point concentration was 0.163 mmol / g.
[0038]
In Production Examples 1 to 3, the number average molecular weight obtained from polyol A: a mixed dicarboxylic acid of adipic acid / isophthalic acid = 1/1 (molar ratio) and a mixed diol of NPG / EG = 9/1 (molar ratio) = 2 2,000 polyester diol polyol B: polyester diol polyol having a number average molecular weight of 2,000 obtained from a mixed diol of adipic acid and EG / DEG = 1/1 (molar ratio) C: terephthalic acid / isophthalic acid = 1 / 1 (molar ratio) of a mixed dicarboxylic acid and NPG / EG = 1/1 (molar ratio) of a mixed diol and a polyester diol polyol having a number average molecular weight of 2,000 D: adipic acid and NPG / HD = 1 / 1 (molar ratio) polyester diol obtained from a mixed diol having a number average molecular weight of 2,000 NPG: neopentylglycol Coal EG: ethylene glycol DEG: diethylene glycol HD: 1,6-hexanediol TMP: trimethylolpropane HDI: hexamethylene diisocyanate IPDI: isophorone diisocyanate DOTDL: dioctyltin dilaurate
[Production of polyisocyanate resin for curing agent]
Production Example 4
After putting 991 g of HDI and 9 g of 1,3-BD into a 1 L capacity reactor equipped with a stirrer, thermometer, nitrogen seal tube and condenser, the inside of the reactor was replaced with nitrogen and stirred. The mixture was heated to a reaction temperature of 80 ° C. while reacting at the same temperature for 2 hours. The measured isocyanate group content of the reaction solution was 48.6%. Next, 0.2 g of potassium caprate as a catalyst and 1.0 g of phenol as a cocatalyst were added, and an isocyanurate-forming reaction was performed at 60 ° C. for 6 hours. 0.14 g of phosphoric acid as a terminator was added to the reaction solution, and the mixture was stirred at the reaction temperature for 1 hour to perform a termination reaction. This reaction product was subjected to thin-film distillation at 130 ° C. × 0.04 kPa to obtain an isocyanurate group-containing polyisocyanate NCO-1. NCO-1 is a pale yellow transparent liquid, isocyanate group content 20.8%, viscosity 2,500 mPa · s / 25 ° C., free HDI content 0.1%, number average molecular weight 770, average number of functional groups 3.8, FT-IR and ¹³ C-NMR confirmed the presence of isocyanate, isocyanurate, and urethane groups. The yield was 35%.
[0040]
Production Example 5
HDI (950 g) and MPD (5 g) were charged into a 1 L reactor having the same capacity as in Synthesis Example 4, and a urethanization reaction was performed at 90 ° C. for 2 hours. When the reaction product was analyzed by FT-IR, the hydroxyl group had disappeared. Next, 0.2 g of zirconium 2-ethylhexanoate was charged and reacted at 110 ° C. for 4 hours. When the reaction product was analyzed by FT-IR and ¹³ C-NMR, the urethane group had disappeared. Next, 0.1 g of phosphoric acid was charged and a termination reaction was performed at 50 ° C. for 1 hour. The isocyanate content of the reaction product after the termination reaction was 40.4%. This reaction product was subjected to thin-film distillation at 130 ° C. × 0.04 kPa to obtain allophanate group-containing polyisocyanate NCO-2. NCO-2 has an isocyanate content of 19.2%, a viscosity at 25 ° C. of 1,720 mPa · s, a number average molecular weight of 1,070, an average number of functional groups of 4.9, and a free hexamethylene diisocyanate content of 0.1%. Met. Further, when NCO-2 was analyzed by FT-IR and ¹³ C-NMR, no urethane group was confirmed and the presence of an allophanate group was confirmed. The uretdione group and the isocyanurate group were traces.
[0041]
In Production Examples 4 and 5, HDI: hexamethylene diisocyanate 1,3-BD: 1,3-butanediol MPD: 3-methyl-1,5-pentanediol
(Adhesive evaluation)
Examples 1 to 16, Comparative Examples 1 to 16
First, an adhesive having the composition shown in Tables 1 to 4 is applied to a deposition surface of a deposition film (PET, NY) at room temperature by a dry laminator, and the solvent is volatilized. Then, the adhesive application surface is bonded to LLDPE. Was. Thereafter, these laminated films were cured at 40 ° C. for 3 days to cure the adhesive. Thereafter, an adhesive test, a seal strength test, and a tear test were performed to evaluate the adhesive. The results are shown in Tables 1 to 4. Examples 1 to 8 and Comparative Examples 1 to 8 (Tables 1 and 2) are evaluations of PET / LLDPE, and Examples 9 to 16 and Comparative Examples 9 to 16 (Tables 3 and 4) are evaluations of NY / LLDPE. The films used for the test are as follows.
Evaporated PET: GL-AE
Alumina deposition thickness: 12 μm
Toppan printing evaporation NY: GL-AEY
Silica deposition thickness: 12 μm
Toppan Printing LLDPE: Tocello T. U. X. -FCS # 60
Thickness: 60 μm
Made by East Cello [0043]
1) Adhesion test:
A test piece having a length of 300 mm and a width of 15 mm was prepared from the prepared laminated film, and the adhesive strength was measured at a peeling speed of 200 mm / min by a T-shaped peeling test method using an Instron tensile tester. did.
[0044]
2) Seal strength test:
Two sheets of the prepared laminated film were stacked with the LLDPE surface inside, heat-sealed, and a test piece having a size of 300 mm long × 15 mm wide was prepared from the sealed portion, using an Instron type tensile tester, The adhesive strength was measured at a peel speed of 200 mm / min by a T-type peel test method.
[0045]
3) Tear test:
A 5 mm incision was made in the end of the composite film, which was torn by hand for evaluation. In the table, the viewpoint of tearing property is that ◎ means tearing without resistance and tearing apart, ○ means that slight resistance is felt but no tearing off, △ means resistance is large but tearing off is small, and × means base material and LLDPE. Means that they cry and do not tear cleanly.
[0046]
[Table 1]

[0047]
[Table 2]

[0048]
[Table 3]

[0049]
[Table 4]

[0050]
From Tables 2 and 4, when the blending ratio of the polyisocyanate curing agent is too small (Comparative Examples 1, 2, 7, and 8), the adhesion between the inorganic surface and the adhesive is insufficient because the adhesiveness between the inorganic surface and the adhesive is insufficient. It is thought that interfacial fracture occurred at, and tearing occurred at the time of tearing. When the blending ratio of the polyisocyanate curing agent is too large (Comparative Examples 5, 6, 11, and 12), crosslinking of polyisocyanate molecules is not efficient, so that the strength of the adhesive layer is reduced and tearing occurs at the time of tearing. I think that the. In Comparative Examples 3, 4, 9, and 10 in which the main agent is a branched type, since the molecular weight of the main agent is small, the flexibility of the molecules between the cross-linking points is lost and the adhesiveness is reduced. On the other hand, Examples in which the blending ratio of the polyisocyanate curing agent was appropriate showed good results in adhesiveness, heat sealability, and tearability irrespective of the type of the base agent and the curing agent.
[0051]
【The invention's effect】
As described above, a laminate film having excellent adhesiveness and tearability can be easily obtained by the present invention.

Claims (2)

A laminating adhesive in which a hydroxyl group-terminated polyurethane resin (A) and a polyisocyanate curing agent (B) are blended at a mass ratio of (A) :( B) = 100: 30 to 100: 100 is used to form an inorganic layer. In the method of manufacturing a laminated film that is applied to a plastic film that has been applied, and a heat-fusible plastic film is attached and heat-cured,
(A) the isocyanurate-modified poly (hexamethylene diisocyanate) having a substantial average number of functional groups of 2, a number average molecular weight of 10,000 to 50,000 and (B) a substantial average number of functional groups of 2 to 10; A method for producing a laminate film, which is an isocyanate. Laminating adhesives, and wherein the coating amount of the plastic film to form an inorganic layer is 1 to 10 g / m ² in a dry state, a manufacturing method of the laminate film according to claim 1.