Laminated body for blister packaging and blister packaging

Abstract

The present invention provides a laminate for blister packaging having excellent lamination strength and formability and excellent moisture-heat resistance and external stress resistance after forming, and a blister packaging having excellent moisture-heat resistance and external stress resistance. The laminate for blister packaging comprises a structure in which at least an outer resin film layer (1), an outer adhesive layer (2), a metal foil layer (3), an inner adhesive layer (4), and an inner resin film layer (5) are laminated in this order, wherein the outer adhesive layer (2) is formed of a polyurethane adhesive containing a main agent (A) and a hardener, wherein the main agent (A) contains a polyurethane resin (a) having a hydroxyl group, and the hardener contains a polyisocyanate component (B), wherein the polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol and a polyisocyanate, and has an ester bond concentration of 9.20 mmol / g to 10.50 mmol / g.

Description

Technical Field

[0001] The present invention relates to a laminate for blister packing that is used for packaging pharmaceuticals and the like after being molded, and a blister pack including a cover material on the laminate for blister packing. The present invention also relates to a laminate for blister packing and a blister pack having a good appearance and excellent adhesive strength, moldability, and resistance to external stress. Background Art

[0002] As a container for packaging granular pharmaceutical tablets or snacks, a blister package is known, which is formed by vacuum forming a blister package laminate, wherein the blister package laminate comprises an outer resin film layer (1), an outer adhesive layer (2), a metal foil layer (3), an inner adhesive layer (4), and a heat seal layer (5) laminated in this order from the outside. In addition to requiring airtightness or moisture-proof properties to protect the contents, the blister package is also required to have excellent formability in order to package larger contents.

[0003] Patent Document 1 discloses a molding packaging material comprising an adhesive layer using a two-component curing polyester urethane adhesive containing a specific polyester polyol and a polyfunctional isocyanate between a heat-resistant resin layer and a metal foil layer. The patent also states that the molding packaging material can be used as a packaging material for pharmaceuticals.

[0004] Patent Document 2 discloses a laminate for blister packaging including an adhesive layer containing a main agent comprising a polyester polyol and an epoxy compound, and a curing agent comprising an isocyanate compound at a predetermined ratio.

[0005] Patent Document 3 discloses a packaging material comprising a laminated adhesive layer containing a polyisocyanate component, a polyester-polyurethane polyol component having a specific weight-average molecular weight, and an epoxy component having a specific epoxy equivalent. The document also states that the packaging material can be used as a pharmaceutical packaging material.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-024862

[0009] [Patent Document 2] International Publication No. 2018 / 047672

[0010] [Patent Document 3] Japanese Patent Application Publication No. 2019-156925 Summary of the Invention

[0011] [Problems to be solved by the invention]

[0012] In recent years, demand for highly complex or complex molding has increased in order to package larger and more diverse contents, requiring even better formability. Furthermore, to protect the contents, it is required that the bonding strength between the layers be maintained high even during long-term storage in high-temperature, high-humidity environments. Furthermore, to protect the contents, it is also required that the metal foil in the laminate not break if the formed portion deforms due to external forces.

[0013] However, the packaging materials described in Patent Documents 1 and 2 use a non-urethanized polyester resin as the main component, resulting in a low molecular weight and, therefore, insufficient lamination strength. Consequently, these packaging materials suffer from the problem of adhesive layer degradation and difficulty maintaining adhesive strength during long-term storage in high-temperature, high-humidity environments. Furthermore, the metal foil in the laminate is susceptible to fracture when external stress is applied to the molded portion.

[0014] The packaging material described in Patent Document 3 has a problem in that the lamination strength is sometimes insufficient due to the low ester bond concentration of the polyurethane polyol, and the metal foil in the laminate is easily broken when external stress is applied to the molded portion.

[0015] Therefore, an object of the present invention is to provide a laminate for blister packaging, which has excellent lamination strength and moldability and, after molding, has excellent resistance to heat and moisture and external stress. Another object of the present invention is to provide a blister packaging having excellent resistance to heat and moisture and external stress.

[0016] [Technical means to solve the problem]

[0017] As a result of intensive studies to solve the above-described problems, the present inventors have found that the above-described problems can be solved by the embodiments described below, thereby completing the present invention.

[0018] A laminate for blister packaging according to one embodiment of the present invention comprises a structure in which at least an outer side resin film layer (1), an outer side adhesive layer (2), a metal foil layer (3), an inner side adhesive layer (4) and an inner side resin film layer (5) are laminated in sequence, wherein the outer side adhesive layer (2) is formed by a polyurethane adhesive containing a main agent (A) and a hardener, the main agent (A) contains a polyurethane resin (a) having a hydroxyl group, the hardener contains a polyisocyanate component (B), the polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol and a polyisocyanate, and the ester bond concentration is 9.20 mmol / g to 10.50 mmol / g.

[0019] In the laminate for blister packs according to one embodiment of the present invention, the polyurethane resin (a) having a hydroxy group has a urethane bond concentration of 0.10 mmol / g to 0.90 mmol / g.

[0020] In the laminate for blister packs according to one embodiment of the present invention, the polyurethane resin (a) having a hydroxyl group has a hydroxyl value of 0.5 mgKOH / g to 20 mgKOH / g.

[0021] In the laminate for blister packs according to one embodiment of the present invention, the polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol having a weight average molecular weight of 5,000 to 30,000 and polyisocyanate.

[0022] In the laminate for blister packs according to one embodiment of the present invention, the weight average molecular weight of the polyurethane resin (a) having a hydroxyl group is 50,000 to 100,000.

[0023] In the laminate for blister packaging according to one embodiment of the present invention, the outer resin film layer (1) is polyamide.

[0024] In the laminate for blister packaging according to one embodiment of the present invention, the inner resin film layer (5) is polyvinyl chloride.

[0025] The blister package according to one embodiment of the present invention includes a cover material on the blister package laminate.

[0026] In the blister package according to an embodiment of the present invention, the cover material comprises a metal layer.

[0027] [Effects of the Invention]

[0028] The present invention provides a blister pack laminate having excellent lamination strength and moldability, and excellent resistance to moisture and heat and external stress after molding. Furthermore, the present invention provides a blister pack having excellent resistance to moisture and heat and external stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic cross-sectional view of the laminate for blister packs according to the present embodiment.

[0030] Figure 2 This is a schematic cross-sectional view of the blister package according to this embodiment.

[0031] [Explanation of Symbols]

[0032] 1: Outer resin film layer

[0033] 2: Outer adhesive layer

[0034] 3: Metal foil layer

[0035] 4: Inner adhesive layer

[0036] 5: Inner side resin film layer

[0037] 6: Contents

[0038] 7: Cover material DETAILED DESCRIPTION

[0039] 《Laminates for blister packaging》

[0040] The laminate for blister packaging of the present embodiment is a blister packaging film having the following structure. That is, it includes a structure in which at least an outer resin film layer (1), an outer adhesive layer (2), a metal foil layer (3), an inner adhesive layer (4), and an inner resin film layer (5) are laminated in this order from the outside. In addition, the outer adhesive layer (2) is formed by a polyurethane adhesive containing a main agent (A) and a hardener, wherein the main agent (A) contains a polyurethane resin (a) having a hydroxyl group, and the hardener contains a polyisocyanate component (B). Furthermore, the polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol and a polyisocyanate, and has an ester bond concentration of 9.20 mmol / g to 10.50 mmol / g.

[0041] Hereinafter, this embodiment will be described in detail by taking preferred aspects as examples.

[0042] <Outer Adhesive Layer (2)>

[0043] The outer adhesive layer (2) in this embodiment is formed of a polyurethane adhesive containing a main agent (A) and a hardener, wherein the main agent (A) includes a polyurethane resin (a) having a hydroxyl group and the hardener includes a polyisocyanate component (B). Alternatively, the outer adhesive layer (2) may be a cured product (hardened product) of a polyurethane adhesive containing the main agent (A) and the hardener.

[0044] First, the main agent will be described. The main agent and the hardener may contain known additives within a range that does not impair the effects of the present invention.

[0045] [Polyurethane resin having hydroxyl group (a)]

[0046] The polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol and a polyisocyanate, and has an ester bond concentration of 9.20 mmol / g to 10.50 mmol / g. The polyurethane resin (a) having a hydroxyl group can be obtained by reacting the hydroxyl groups in a polyol including a polyester polyol described below with the isocyanate groups in a polyisocyanate under conditions such that the hydroxyl groups are in excess.

[0047] (Polyester polyol)

[0048] The polyester polyol is not limited to the following, and examples thereof include polyester polyols obtained by reacting a carboxylic acid component and a hydroxyl component.

[0049] Examples of the carboxylic acid component include dibasic acids having an aromatic ring, such as terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, and phthalic anhydride; aliphatic dibasic acids, such as adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, and itaconic anhydride; or dialkyl esters thereof or mixtures thereof.

[0050] Examples of the hydroxyl component include polyols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, butanediol, neopentyl glycol, dineopentyl glycol, trimethylolpropane, glycerol, 1,6-hexanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 3,3′-dimethylolheptane, 1,9-nonanediol, polyoxyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, and polyurethane polyol; and mixtures thereof.

[0051] The carboxylic acid component and the hydroxyl component may be used alone or in combination of two or more.

[0052] Based on the total carboxylic acid components, the carboxylic acid components preferably contain 5 to 55 mol% of an aliphatic dibasic acid. If the aliphatic dibasic acid is added in an amount of 5 mol% or more, the solvent solubility is improved, and the resulting polyester polyol solution has a low viscosity. This improves the coating properties of the polyurethane adhesive, and a packaging material with a more excellent appearance can be obtained. If it is 55 mol% or less, the glass transition temperature of the polyester polyol is easily adjusted, and the adhesive strength is further improved. From the same point of view, based on the total carboxylic acid components, the aliphatic dibasic acid is more preferably added in an amount of 25 to 50 mol%.

[0053] The ester bond concentration of the polyester polyol is preferably 9.40 mmol / g to 10.80 mmol / g, more preferably 9.40 mmol / g to 10.30 mmol / g, and even more preferably 9.40 mmol / g to 9.80 mmol / g.

[0054] When the polyester polyol has an ester bond concentration of 9.40 mmol / g or higher, its solubility in ester solvents such as ethyl acetate is excellent, and the amount of isocyanate used for urethanization is not limited, thus readily exhibiting good adhesion, which is preferred. When the ester bond concentration is 10.80 mmol / g or lower, it is further preferred because the increase in viscosity and the decrease in solvent solubility caused by intermolecular interactions due to the ester bonds can be suppressed.

[0055] The ester bond concentration of the polyester polyol can be calculated using the following calculation formula.

[0056] Formula: Polyester bond concentration (mmol / g) = molar amount of carboxylic acid component × sum of the number of carboxylic acid functional groups / (total amount charged × solid yield) × 1000

[0057] If the polyester 1 of Synthesis Example 1 described later is cited as an example, then

[0058] Isophthalic acid (functional group 2): 148 g = 0.892 mol,

[0059] Terephthalic acid (functional group 2): 296g = 1.783mol,

[0060] Adipic acid (functional group 2): 260 g = 1.780 mol,

[0061] The total loading amount was 1000.05 g, and the yield was 83.9%.

[0062] The ester bond concentration of polyester 1 can be calculated as

[0063] (0.892×2+1.783×2+1.780×2) / (1000.5×0.839)×1000=10.63.

[0064] The weight average molecular weight of the polyester polyol is preferably 5,000 to 30,000, more preferably 15,000 to 25,000. A weight average molecular weight of 5,000 or greater further improves adhesion to substrates and improves processability. A weight average molecular weight of 30,000 or less easily prevents excessively low concentrations of hydroxyl groups at the polyester polyol terminals, and easily prevents prolonged reaction times when reacting with a polyisocyanate (described later) to obtain a polyurethane resin (a) having hydroxy groups.

[0065] As the polyol constituting the polyurethane resin (a) having a hydroxyl group, in addition to the polyester polyols described above, conventionally known polyols can be used in combination. Examples of the polyols that can be used in combination include hydroxyl components that can be used to synthesize the polyester polyols described above, and preferably neopentyl glycol or 1,4-butanediol can be used.

[0066] (Polyisocyanate)

[0067] Examples of the polyisocyanate constituting the polyurethane resin (a) having a hydroxyl group include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, monomers of trifunctional or higher-functional polyisocyanates, and various derivatives derived from these diisocyanates.

[0068] Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methylhexanoate.

[0069] Examples of the alicyclic diisocyanate include 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,4-bis(isocyanatemethyl)cyclohexane, and 1,3-bis(isocyanatemethyl)cyclohexane.

[0070] Examples of the aromatic diisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture thereof, 4,4′-toluidine diisocyanate, disanisidine diisocyanate, and 4,4′-diphenyl ether diisocyanate.

[0071] Examples of the aromatic aliphatic diisocyanate include 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, or a mixture thereof, ω,ω′-diisocyanate-1,4-diethylbenzene, 1,3-bis(1-isocyanate-1-methylethyl)benzene, 1,4-bis(1-isocyanate-1-methylethyl)benzene, or a mixture thereof.

[0072] Examples of trifunctional or higher-functional polyisocyanate monomers include triisocyanates such as triphenylmethane-4,4′,4″-triisocyanate, 1,3,5-triisocyanate benzene, and 2,4,6-triisocyanate toluene; and tetraisocyanates such as 4,4′-diphenyldimethylmethane-2,2′-5,5′-tetraisocyanate.

[0073] As various derivatives derived from the above-mentioned diisocyanates, there can be used: adducts (adducts) of the above-mentioned diisocyanates with low-molecular-weight polyols having a molecular weight of less than 200, such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3′-dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, or castor oil; trimers of the above-mentioned diisocyanates (also called trimers, urate bodies); biuret bodies; allophanate bodies; in addition, polyisocyanates having a 2,4,6-oxadiazinetrione ring obtained from carbon dioxide and the above-mentioned diisocyanates can also be used.

[0074] As the polyisocyanate constituting the polyurethane resin (a) having a hydroxyl group, aromatic isocyanates and alicyclic diisocyanates are preferred. Furthermore, from the perspective of moldability and adhesion after a high-temperature and high-humidity test, toluene diisocyanate, 4,4′-diphenyl diisocyanate, and 3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate are more preferred.

[0075] The reaction temperature of the polyol and the polyisocyanate for obtaining the polyurethane resin (a) having a hydroxyl group is preferably in the range of 50° C. to 200° C., more preferably in the range of 80° C. to 150° C. In the urethanization reaction, the molar ratio of the isocyanate groups of the polyisocyanate to the hydroxyl groups in the polyol (the number of moles of isocyanate groups / the number of moles of hydroxyl groups) is preferably 0.1 to 0.9, more preferably 0.3 to 0.8.

[0076] In this embodiment, it is important that the ester bond concentration of the polyurethane resin (a) having a hydroxyl group constituting the outer adhesive layer is in the range of 9.20 mmol / g to 10.50 mmol / g. By controlling the ester bond concentration within a predetermined range, the stability of the adhesive in solution and the affinity for the substrate based on the ester bond are suppressed, thereby achieving excellent coating properties. As a result, the obtained laminate does not exhibit reduced interlayer bonding strength even after high temperature and high humidity / long-term durability testing, has excellent formability, and does not produce appearance defects such as floating between layers. Furthermore, even if the formed portion is deformed by external force, the laminate will not break.

[0077] If the ester bond concentration of the hydroxyl-containing polyurethane resin (a) is less than 9.20 mmol / g, solubility in ester solvents such as ethyl acetate decreases, leading to reduced coating properties. Alternatively, affinity for the substrate due to the ester bond decreases, reducing adhesive strength. If the ester bond concentration exceeds 10.50 mmol / g, intermolecular interactions due to the ester bond increase, resulting in increased viscosity or reduced solvent solubility, leading to a decrease in appearance after aging due to coating defects.

[0078] The ester bond concentration of the polyurethane resin (a) having a hydroxy group is preferably 9.20 to 10.10 mmol / g, more preferably 9.20 to 9.60 mmol / g.

[0079] The ester bond concentration of the polyurethane resin (a) having a hydroxyl group can be calculated using the following calculation formula.

[0080] Calculation formula: Ester bond concentration (mmol / g) = ester bond concentration of polyester polyol × ratio of polyester polyol to the total mass of polyol and polyisocyanate constituting urethane resin (mass %)

[0081] For example, the ester bond concentration of the polyurethane resin (a) having a hydroxyl group shown in Synthesis Example (a)-1 described later becomes

[0082] Ester bond concentration = 10.63 × (100 / 102) = 10.42 mmol / g.

[0083] The polyurethane bond concentration of the hydroxyl group-containing polyurethane resin (a) is preferably in the range of 0.10 mmol / g to 0.90 mmol / g, more preferably 0.15 mmol / g to 0.60 mmol / g, and even more preferably 0.20 mmol / g to 0.40 mmol / g. A urethane bond concentration of 0.10 mmol / g or higher is preferred because it achieves excellent compatibility improvement, improving appearance and adhesion. A urethane bond concentration of 0.90 mmol / g or lower is preferred because it prevents excessively high urethane bond concentration and achieves an appropriate viscosity, resulting in excellent coating properties and appearance.

[0084] By controlling the urethane bond concentration of the polyurethane resin (a) having a hydroxyl group, compatibility with the polyisocyanate component (B) as a curing agent can be improved, and an adhesive layer having a high crosslinking density and excellent durability and appearance can be formed.

[0085] The urethane bond concentration can be calculated using the following formula 1.

[0086] Formula 1:

[0087] Urethane bond concentration (mmol / g) = [(NCO content of polyisocyanate (mass %) ÷ 100) × (ratio of polyisocyanate (mass %) to the total (mass %) of polyol and polyisocyanate constituting the urethane resin) ÷ 42 × 1000] + [(number of urethane bonds in polyisocyanate ÷ molecular weight of polyisocyanate) × (ratio of polyisocyanate (mass %) to the total (mass %) of polyol and polyisocyanate constituting the urethane resin) × 1000]

[0088] For example, since the NCO content of toluene diisocyanate is 48.2% by mass, the amount of polyisocyanate added to the polyol is 2% by mass, and the number of internal urethane bonds is zero, the urethane bond concentration of the polyurethane resin (a) having a hydroxyl group shown in Synthesis Example (a)-1 described later is

[0089] Urethane bond concentration = 0.482 × (2 / 102) / 42 × 1000

[0090] =0.23mmol / g.

[0091] The weight average molecular weight of the polyurethane resin (a) having a hydroxy group is preferably 50,000 to 100,000, more preferably 50,000 to 80,000.

[0092] A weight-average molecular weight of 50,000 or greater further improves the resin's elongation and processability. A weight-average molecular weight of 100,000 or less prevents excessively high viscosity of the adhesive solution, further reducing the likelihood of poor appearance. Furthermore, by controlling the weight-average molecular weight to 50,000 to 80,000, it becomes easier to achieve a balance between the resin's elongation and the adhesive solution's viscosity, making it more preferable for use.

[0093] The hydroxyl value of the polyurethane resin (a) having a hydroxyl group is preferably 0.5 mgKOH / g to 20 mgKOH / g, more preferably 3 mgKOH / g to 10 mgKOH / g. The hydroxyl group is used in the crosslinking reaction with the polyisocyanate component (B) described below. The crosslinking reaction increases the molecular weight of the adhesive, thereby improving the heat resistance of the laminate. The hydroxyl value can be determined, for example, by a method in accordance with Japanese Industrial Standards (JIS) K 1557-1.

[0094] The main component (A) of the polyurethane adhesive only needs to contain the polyurethane resin (a) having a hydroxyl group, and may further contain the following components as other components. The other components may be blended into either the main component (A) or the hardener containing the polyisocyanate component (B), or may be added when the main component (A) and the hardener containing the polyisocyanate component (B) are blended. More preferably, they are blended into the main component (A).

[0095] (Solvent)

[0096] To adjust the coating liquid to an appropriate viscosity when applying the polyurethane adhesive to the substrate, the polyurethane adhesive may contain a solvent within a range that does not affect the substrate during the drying process. Examples of solvents include: ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and methoxyethyl acetate; ether compounds such as diethyl ether and ethylene glycol dimethyl ether; aromatic compounds such as toluene and xylene; aliphatic compounds such as pentane and hexane; halogenated hydrocarbon compounds such as dichloromethane, chlorobenzene, and chloroform; alcohols such as ethanol, isopropyl alcohol, and n-butanol; and water. These solvents may be used alone or in combination of two or more. Ethyl acetate is preferably used among these.

[0097] (Reaction accelerator)

[0098] To promote the urethanization reaction, the polyurethane adhesive may further contain a reaction accelerator. Examples of the reaction accelerator include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; tertiary amines such as 1,8-diazabicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene-5,6-dibutylamino-1,8-diazabicyclo(5,4,0)undecene-7; and reactive tertiary amines such as triethanolamine. The polyurethane adhesive may also contain one or more reaction accelerators selected from this group.

[0099] (Silane coupling agent)

[0100] To enhance bonding strength to metallic materials such as metal foil, polyurethane adhesives may further contain a silane coupling agent. Examples of silane coupling agents include trialkoxysilanes containing a vinyl group, such as vinyltrimethoxysilane and vinyltriethoxysilane; trialkoxysilanes containing an amino group, such as 3-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; and trialkoxysilanes containing a glycidyl group, such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.

[0101] The content of the silane coupling agent is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the solid content of the polyurethane resin (a) having a hydroxyl group. By adding the silane coupling agent in this range, the bonding strength to the metal foil can be further improved.

[0102] (Epoxy resin)

[0103] To enhance the bonding strength to metallic materials such as metal foil, polyurethane adhesives may further include epoxy resins. In particular, when epoxy resins are added to polyurethane resin (a) having a polyester backbone, the epoxy resins react with the acid generated by hydrolysis during moist heat resistance, thereby further enhancing moist heat resistance.

[0104] The epoxy resin is not limited to the following, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, polyglycerol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether, propylene oxide-modified bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether.

[0105] These epoxy resins may be used alone or in combination of two or more.

[0106] Among them, from the viewpoint of adhesive strength and resistance to moisture and heat, an epoxy resin having a weight average molecular weight of 400 to 10,000 is preferred. From the viewpoint of adhesive strength and resistance to moisture and heat, the amount of epoxy resin blended is preferably 5 to 50 parts by mass, more preferably 20 to 40 parts by mass, relative to 100 parts by mass of the polyurethane resin (a) having a hydroxyl group. By setting the blending amount of the epoxy resin to 5 parts by mass or more, resistance to moisture and heat can be more effectively improved. In addition, by setting the blending amount of the epoxy resin to 50 parts by mass or less, the hardness of the adhesive layer can be moderately softened, making it easy to exhibit sufficient adhesiveness.

[0107] The epoxy equivalent of the epoxy resin is preferably 200 g / eq to 5,000 g / eq, more preferably 200 g / eq to 1,000 g / eq. By using an epoxy resin with an epoxy equivalent of 200 g / eq to 5,000 g / eq, it is easy to achieve both adhesive strength and laminated appearance.

[0108] (Phosphoric acid or its derivatives)

[0109] To improve the bonding strength to metallic materials such as metal foil, polyurethane adhesives may contain phosphoric acid or a phosphoric acid derivative. Phosphoric acid can be any type of phosphoric acid as long as it contains at least one free oxygen-containing acid. Examples include: phosphoric acids such as hypophosphorus acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid; and condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid. Derivatives of phosphoric acid include those obtained by partially esterifying the phosphoric acid with an alcohol while leaving at least one free oxygen-containing acid. Examples of these alcohols include: aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerol; and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. Phosphoric acid or its derivatives may be used alone or in combination of two or more. The total amount of phosphoric acid or its derivatives added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.05 to 1 part by mass, relative to 100 parts by mass of the polyurethane resin (a) having a hydroxy group.

[0110] In order to improve the laminated appearance of the laminate, the polyurethane adhesive may further contain a leveling agent or a defoaming agent.

[0111] Examples of the leveling agent include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl-containing polydimethylsiloxane, polyetherester-modified hydroxyl-containing polydimethylsiloxane, acrylic copolymers, methacrylic copolymers, polyether-modified polymethylalkylsiloxane, alkyl acrylate copolymers, alkyl methacrylate copolymers, and lecithin.

[0112] Examples of the defoaming agent include known defoaming agents such as silicone resins, silicone solutions, and copolymers of alkyl vinyl ethers, alkyl acrylates, and alkyl methacrylates.

[0113] The polyurethane adhesive may contain additives other than those listed above, as long as the effects of the present invention are not impaired. Examples of additives include inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes, layered inorganic compounds, stabilizers (antioxidants, heat stabilizers, UV absorbers, hydrolysis inhibitors, etc.), rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, anti-blocking agents, colorants, fillers, crystal nucleating agents, and catalysts for adjusting the curing reaction.

[0114] In the main component (A), the solution obtained by mixing the aforementioned additives with the hydroxyl-containing polyurethane resin (a) requires storage stability without causing apparent turbidity or changes in viscosity at low or high temperatures. Turbid, incompatible sites can sometimes become the starting point of cracks during molding. Furthermore, changes in viscosity can make it difficult to adjust the coating process.

[0115] [Polyisocyanate component (B)]

[0116] The polyisocyanate component (B) cross-links with the hydroxyl groups in the hydroxyl-containing polyurethane resin (a), thereby increasing the molecular weight of the adhesive layer and enhancing the internal cohesive force exhibiting energy elasticity. Furthermore, since isocyanate groups react with water to form urea bonds with high cohesive force, the cohesive force of the adhesive layer can be enhanced by self-cross-linking during curing.

[0117] Typically, urethane bonds or urea bonds generated by crosslinking reactions have hydrogen bonds and high polarity, resulting in poor compatibility with resins, sometimes resulting in poor appearance or defects during molding. However, in this embodiment, by combining a polyurethane resin (a) having a predetermined hydroxyl group with a polyisocyanate component (B), a strong adhesive layer with excellent compatibility, good appearance, and toughness can be formed. As a result, good physical properties can be obtained as a laminate for blister packaging.

[0118] The polyisocyanate component (B) also enhances the interaction with the substrate surface, as described below. In particular, when using a substrate that has been subjected to physical treatments such as corona discharge treatment or chemical treatments such as acid modification, the reactive functional groups in the polyisocyanate component (B) chemically react with the hydroxyl groups on the substrate surface, thereby achieving a strong interaction between the outer adhesive layer and the substrate.

[0119] As described above, by using the polyisocyanate component (B), a strong outer adhesive layer can be formed, and the adhesive layer can suppress the expansion and contraction movement of the substrate caused by a sudden environmental change and maintain a high level of adhesive strength.

[0120] As the polyisocyanate component (B), the compounds listed in the section (polyisocyanate) constituting the polyurethane resin (a) having a hydroxyl group can be used in the same manner. These can be used alone or in combination of two or more.

[0121] Among them, the polyisocyanate component (B) is preferably a urate body of diisocyanate, an adduct of trimethylolpropane added to diisocyanate, a biuret type, a prepolymer having an isocyanate residue (a low polymer obtained from diisocyanate and a polyol), a uretdione body having an isocyanate residue, an allophanate body or a complex thereof.

[0122] In blister packaging applications, it is preferred to use an aromatic isocyanate or a derivative thereof as the polyisocyanate component (B) from the viewpoint of achieving excellent heat resistance, high cohesive force, and processability.

[0123] In addition, it is preferred that the polyisocyanate constituting the polyurethane resin (a) having a hydroxyl group is the same as the polyisocyanate component (B) because compatibility is further improved. That is, the polyisocyanate component (B) is more preferably toluene diisocyanate or an adduct of toluene diisocyanate with trimethylolpropane added thereto.

[0124] With the solid content mass 100% by mass of the polyurethane resin (a) having a hydroxyl group as a benchmark, the content of the polyisocyanate component (B) is preferably 10% to 40% by mass, more preferably 10% to 30% by mass. If the content of the polyisocyanate component (B) is 10% by mass or more, the molecular weight of the adhesive layer can be increased more efficiently. Thus, the internal cohesion is improved, and high bonding strength can be easily obtained. If the content of the polyisocyanate component (B) is 40% by mass or less, the amount of the high polarity urethane bond or urea bond generated by the cross-linking reaction can be appropriately controlled, and defects can be easily suppressed during poor appearance or deformation based on processing.

[0125] Production of laminates for blister packaging

[0126] The method for producing the laminated body of the present embodiment is not particularly limited, and the laminated body can be produced by a known method.

[0127] For example, the laminate can be produced by the following production method. First, the outer resin film layer (1) and the metal foil layer (3) are laminated using a polyurethane adhesive forming the outer adhesive layer (2) to obtain an intermediate laminate having a structure of outer resin film layer (1) / outer adhesive layer (2) / metal foil layer (3). Subsequently, the inner resin film layer (5) is laminated on the metal foil layer (3) surface of the intermediate laminate using an inner adhesive, thereby producing the laminate of this embodiment (hereinafter referred to as production method 1).

[0128] Alternatively, the laminate can be produced by the following production method. First, a metal foil layer (3) and an inner resin film layer (5) are laminated using an inner adhesive to obtain an intermediate laminate having a structure of metal foil layer (3) / inner adhesive layer (4) / inner resin film layer (5). Thereafter, the metal foil layer (3) of the intermediate laminate and the outer resin film layer (1) are laminated using the polyurethane adhesive, thereby producing the laminate of this embodiment (hereinafter referred to as production method 2).

[0129] In the case of manufacturing method 1, it is preferably as follows. First, the polyurethane adhesive is applied to one side of either the outer resin film layer (1) or the metal foil layer (3) to evaporate the solvent. Thereafter, another substrate is superimposed on the uncured outer adhesive layer under heat and pressure, and then aged at room temperature (e.g., 25°C) to less than 100°C to cure the outer adhesive layer. If the aging temperature is less than 100°C, thermal shrinkage of the outer resin film layer (1) will not occur, and thus a decrease in the elongation at break or the stress at break that affects molding, or a decrease in molding productivity due to film curling, can be easily prevented.

[0130] The amount of polyurethane adhesive (outer layer adhesive) applied after drying is preferably 1 g / m 2 ~15g / m 2 about.

[0131] In the case of the production method 2, the polyurethane adhesive may be applied to either the outer resin film layer (1) surface or the metal foil layer (3) surface of the intermediate laminate.

[0132] Examples of the method for forming the outer adhesive layer include methods using a notch wheel coater, dry laminator, knife coater, die coater, roll coater, rod coater, gravure roll coater, reverse roll coater, blade coater, gravure coater, and micro gravure coater.

[0133] <Outer side resin film layer (1)>

[0134] The outer side resin film layer (1) is not particularly limited, and it is preferred to use a stretched film containing polyamide or polyester, and more preferably to use a stretched film containing polyamide. In addition, the outer side resin film layer (1) can also be colored using pigments such as carbon black or titanium oxide. In addition, the non-laminated surface of the outer side resin film layer (1) can be coated with a coating agent or a slip agent for the purpose of preventing damage or electrolyte resistance, and can also be coated with printing ink for the purpose of design. In addition, the outer side resin film layer (1) can include one layer, or it can be pre-laminated with two or more layers of film. The thickness of the outer side resin film layer (1) is not particularly limited, but is preferably 12μm to 100μm.

[0135] <Metal Foil Layer (3)>

[0136] The metal foil layer (3) is not particularly limited, but is preferably an aluminum foil layer. The thickness of the metal foil layer (3) is not particularly limited, but is preferably 20 μm to 80 μm. In addition, the surface of the metal foil layer (3) is preferably subjected to a known anti-corrosion treatment such as phosphate chromate treatment, chromate chromate treatment, chromium oxide treatment, zinc phosphate treatment, zirconium phosphate treatment, zirconium oxide treatment, titanium phosphate treatment, hydrofluoric acid treatment, cerium treatment, or hydrotalcite treatment.

[0137] <Inner Adhesive Layer (4)>

[0138] The inner adhesive layer (4) is formed of an adhesive and may be a cured product (hardened product) of the adhesive. The adhesive forming the inner adhesive layer (4) is not particularly limited as long as it satisfies the performance required of the laminate for blister packaging. Examples thereof include AD-502 / CAT-10L and AD-585 / CAT-10L (manufactured by Toyo Morton Co., Ltd.).

[0139] In addition, the inner side adhesive layer (4) and the outer side adhesive layer (2) are similarly reaction products of polyester polyol and polyisocyanate, and can be a layer formed by a polyurethane adhesive containing a main agent and a hardener, wherein the main agent contains a polyurethane resin having a hydroxyl group with an ester bond concentration of 9.20 mmol / g to 10.50 mmol / g, and the hardener contains a polyisocyanate component.

[0140] The inner side adhesive layer (4) can be formed, for example, by the following method. First, the inner side adhesive is applied to the metal foil layer (3) using a gravure coater or the like, and the solvent is dried. Subsequently, the inner side resin film layer (5) is overlapped on the adhesive layer under heating and pressure, and then aged at room temperature (e.g., 25°C) or under heating, thereby forming the inner side adhesive layer (4). Alternatively, for example, it can be formed by the following method. First, the inner side adhesive is melt-extruded onto the metal foil layer (3) using a T-die extruder to form an adhesive layer. Then, the inner side resin film layer (5) can be overlapped on the adhesive layer, and the inner side adhesive layer (4) is formed by laminating the metal foil layer (3) and the inner side resin film layer (5).

[0141] When both the outer adhesive layer (2) and the inner adhesive layer (4) need to be aged, for example, the following method can be used. That is, after obtaining a laminated body having a structure in which the outer resin film layer (1), an uncured outer adhesive layer, a metal foil layer (3), an uncured inner adhesive layer, and an inner resin film layer (5) are laminated in this order from the outside, the aging can be performed together.

[0142] The coating amount of the inner layer adhesive after drying is preferably 1 g / m2 ~15g / m 2 about.

[0143] <Inner side resin film layer (5)>

[0144] The inner resin film layer (5) is not particularly limited, but is preferably an unstretched film comprising at least one thermoplastic resin selected from the group consisting of polyvinyl chloride, polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. Of these, polyvinyl chloride is particularly preferably used as the constituent material of the inner resin film layer (5). The thickness of the inner resin film layer is not particularly limited, but is preferably 20 μm to 150 μm.

[0145] Blister Packaging

[0146] Figure 1 This is a schematic cross-sectional view of the laminate for blister packs according to the present embodiment. Figure 2 This is a schematic cross-sectional view of a blister package according to the present embodiment. The blister package according to the present embodiment can be obtained by including a cover material on the blister package laminate. Specifically, the blister package is formed by molding the laminate to form a bag portion in which the outer resin film layer (1) is convex and the inner resin film layer (5) is concave. Furthermore, the blister package includes a structure in which the inner resin film layer (5) and the cover material (7) of the laminate are at least partially bonded. The blister package can accommodate contents (6) in the bag portion between the laminate and the cover material (7).

[0147] From the viewpoint of protecting the contents, the cover material (7) preferably includes a metal layer such as aluminum foil.

[0148] [Example]

[0149] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. "Parts" in Examples and Comparative Examples refer to "parts by mass" unless otherwise specified.

[0150] <Determination of Acid Value (AV)>

[0151] Accurately measure approximately 1 g of the sample (polyester polyol solution) in a co-stoppered Erlenmeyer flask and dissolve it in 100 ml of a toluene / ethanol mixture (volume ratio: toluene / ethanol = 2 / 1). Add phenolphthalein solution as an indicator and hold for 30 seconds. Then, titrate with 0.1N alcoholic potassium hydroxide solution until the solution turns light red. Calculate the acid value (mgKOH / g) according to the following formula.

[0152] Acid value (mgKOH / g) = (5.611 × a × F) / S

[0153] Where, S: the amount of sample taken (g)

[0154] a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)

[0155] F: Titer of 0.1N alcoholic potassium hydroxide solution

[0156] <Determination of Hydroxyl Value (OHV)>

[0157] In a co-stopped conical flask, accurately measure about 1 g of the sample (polyester polyol or polyurethane resin (a) having a hydroxyl group, etc.), add 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2 / 1) and dissolve it. Furthermore, accurately add 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride is dissolved in pyridine and the volume is set to 100 ml) and stir for about 1 hour. Phenolphthalein test solution is added thereto as an indicator and continued for 30 seconds. Afterwards, titrate with 0.5 N alcoholic potassium hydroxide solution until the solution appears light red, and calculate the hydroxyl value (mgKOH / g) according to the following formula.

[0158] Hydroxyl value (mgKOH / g) = [{(ba) × F × 28.05} / S] + D

[0159] Where, S: the amount of sample taken (g)

[0160] a: Consumption of 0.5N alcoholic potassium hydroxide solution (ml)

[0161] b: Consumption of 0.5N alcoholic potassium hydroxide solution in blank experiment (ml)

[0162] F: Titer of 0.5N alcoholic potassium hydroxide solution

[0163] D: Acid value (mgKOH / g)

[0164] <Determination of Number Average Molecular Weight (Mn), Weight Average Molecular Weight (Mw), and Molecular Weight Distribution (Mw / Mn)>

[0165] The average molecular weight and molecular weight distribution were measured using Shodex (registered trademark) (manufactured by Showa Denko Co., Ltd.) and columns KF-805L, KF-803L, and KF-802 (all trade names, manufactured by Showa Denko Co., Ltd.). The values ​​used were those calculated based on standard polystyrene when the column temperature was set to 40° C., tetrahydrofuran (THF) was used as the eluent, the flow rate was set to 0.2 ml / min, detection was performed using an infrared (RI) detector, and the sample concentration was set to 0.02% by mass.

[0166] <Synthesis of Polyester Polyol>

[0167] (Polyester 1)

[0168] 148 parts of isophthalic acid, 296 parts of terephthalic acid, 260 parts of adipic acid, 250 parts of ethylene glycol, and 46 parts of neopentyl glycol were charged and subjected to an esterification reaction at 170°C to 230°C for 10 hours. After distilling off a predetermined amount of water, 0.05 parts of tetraisobutyl titanate were added, and the pressure was gradually reduced. The transesterification reaction was carried out at 1.3 hPa to 2.6 hPa and 230°C to 250°C for 3 hours. As a result, Polyester 1, a polyester polyol with a number average molecular weight (Mn) of 9,200, a weight average molecular weight (Mw) of 19,000, a molecular weight distribution (Mw / Mn) of 2.07, a hydroxyl value of 14.0 mgKOH / g, and an acid value of 0.2 mgKOH / g, was obtained with a yield of 83.9%. The ester bond concentration of Polyester 1 was 10.63 mmol / g.

[0169] Assuming that the excess hydroxyl components are distilled off almost uniformly and the total of the carboxylic acid component and the hydroxyl component is 200 mol %, the composition of the obtained polyester 1 is isophthalic acid:terephthalic acid:adipic acid:ethylene glycol:neopentyl glycol=20:40:40:90:10 (mol %).

[0170] (Polyester 2 to Polyester 12)

[0171] Polyesters 2 to 12 were obtained by reacting the carboxylic acid component and the hydroxyl component in the obtained polyester polyol so that the charged amounts thereof became the blending ratio shown in Table 1, in the same manner as in Polyester 1.

[0172]

[0173] The abbreviations in Table 1 are as follows.

[0174] PA:phthalic acid

[0175] IPA: isophthalic acid

[0176] TPA: terephthalic acid

[0177] SeA: sebacic acid

[0178] AdA: adipic acid

[0179] EG:ethylene glycol

[0180] NPG: neopentyl glycol

[0181] 1,6-HD: 1,6-hexanediol

[0182] MPO: 2-methyl-1,3-propanediol

[0183] DEG: diethylene glycol

[0184] <Synthesis of Hydroxyl-Containing Polyurethane Resin (a)>

[0185] (Carbamate (a)-1)

[0186] 1100 parts of the obtained polyester and 40 parts of ethyl acetate were placed in a 1-liter four-necked flask, heated to 80°C, and stirred until the solution became homogeneous. 2.0 parts of toluene diisocyanate and 0.15 parts of dibutyltin dilaurate were added to the mixture, and the reaction was allowed to proceed for 4 hours. After the reaction was completed, 113 parts of ethyl acetate was added to obtain a solution of urethane (a)-1, a polyurethane resin having a hydroxyl group, having an ester bond concentration of 10.42 mmol / g, a urethane bond concentration of 0.23 mmol / g, an Mn of 23,500, an Mw of 56,100, a glass transition temperature (Tg) of 4°C, a hydroxyl value of 7.9 mgKOH / g, and a non-volatile content of 40% by mass.

[0187] (Carbamate (a)-2 to Carbamate (a)-15, Comparative (a)-1)

[0188] Except for changing the blending amounts shown in Table 2, polyol and polyisocyanate were reacted in the same manner as in urethane (a)-1 to obtain urethane (a)-2 to urethane (a)-15 and comparison (a)-1 as polyurethane resins (a) having hydroxyl groups.

[0189]

[0190] The abbreviations in Table 2 are as follows.

[0191] NPG: Neopentyl Glycol

[0192] TDI: tolylene diisocyanate (Coronate T-80 (trade name), manufactured by Tosoh Corporation, NCO content: 48.2% by mass)

[0193] MDI: 4,4′-diphenylmethane diisocyanate (MILLIONATE MT (trade name), manufactured by Tosoh Corporation, NCO content: 33.5% by mass)

[0194] HDI: Hexamethylene diisocyanate (Desmodur H (registered trademark), manufactured by Covestro, NCO content: 49.9% by mass)

[0195] IPDI: isophorone diisocyanate (Desmodur I (trade name), manufactured by Covestro, NCO content: 37.7% by mass)

[0196] <Manufacturing of Laminated Body for Blister Packaging>

[0197] [Example 1]

[0198] 250 parts (100 parts on a solids basis) of the urethane (a)-1 solution and 1.0 part of glycidoxypropyltrimethoxysilane as an additive were added, stirred for 30 minutes, and then diluted with ethyl acetate to obtain a main agent (A) having a solids concentration of 40% by mass. To this was added 20 parts (15 parts on a solids basis) of coronate L (trade name, manufactured by Tosoh Co., Ltd., solids concentration of 75% by mass, NCO content of 13.2% by mass) and diluted with ethyl acetate to prepare an adhesive solution having a solids concentration of 30% by mass.

[0199] The adhesive solution was applied as an outer adhesive layer (2) on one side of a 25 μm thick stretched polyamide (nylon) film using a dry laminator, and after the solvent was evaporated, an aluminum foil with a thickness of 45 μm was laminated to obtain an intermediate laminate. The amount of adhesive applied after drying was set to 4 g / m 2 .

[0200] Then, the adhesive solution was applied to the other side of the aluminum foil of the intermediate laminate using a dry laminator, and after the solvent was evaporated, a 60 μm thick unstretched polyvinyl chloride film was laminated to obtain a laminate. The amount of adhesive applied after drying was set to 4 g / m 2 .

[0201] Then, the aging was carried out for 7 days at 60°C and 30% RH (relative humidity) to harden the adhesive layers on the outer and inner sides, thereby obtaining a laminate for blister packaging having a structure of outer resin film layer (1) / outer adhesive layer (2) / metal foil layer (3) / inner adhesive layer (4) / inner resin film layer (5).

[0202] [Example 2 to Example 15, Comparative Example 1 to Comparative Example 2]

[0203] Except having changed into the blending amount (parts) of Table 3, the same operation as Example 1 was carried out to obtain a laminate for blister packs.

[0204] <Evaluation of Laminated Material for Blister Packaging>

[0205] The obtained laminate was subjected to the following evaluations. The results are shown in Table 3.

[0206] [Appearance Evaluation of Laminated Body]

[0207] The appearance of each obtained laminate was visually observed and evaluated according to the following criteria.

[0208] A: No whitening or foaming was observed (good)

[0209] B: Some whitening, but no foaming was observed (usable)

[0210] C: Whitening or foaming observed (unusable)

[0211] [Lamination strength (before wet heat test)]

[0212] The resulting laminate was cut into 200 mm x 15 mm pieces and subjected to a T-type peel test using a tensile testing machine to measure the peel strength (N / 15 mm width) between the stretched polyamide film and the aluminum foil. The test was conducted at 20°C, 65% RH, and a load speed of 300 mm / min. Evaluation was based on the average value of the five test pieces and the following criteria.

[0213] A: The average value of peel strength is 7N or more (good)

[0214] B: The average peel strength is 4N or more and less than 7N (usable)

[0215] C: The average peel strength is less than 4N (cannot be used)

[0216] [Lamination strength (after wet heat test)]

[0217] The resulting laminate was placed in a constant temperature and humidity chamber at 85°C and 85% RH for 168 hours. After being removed from the chamber and allowed to stand for 2 hours at 20°C and 65% RH, the same procedures as before the humidity test were repeated. The average peel strength (N / 15 mm width) of the five test pieces was determined. The change from the pre-humidity test was calculated and evaluated according to the following criteria.

[0218] A: The change rate of peel strength is less than 10% (good)

[0219] B: The change rate of peel strength is 10% or more and less than 20% (usable)

[0220] C: Peel strength change rate is 20% or more (cannot be used)

[0221] [Moldability Evaluation]

[0222] The resulting laminate was cut into 80 mm x 80 mm pieces to form blanks. These blanks were then stretched using a straight die with no limit on the forming height, with the stretched polyamide film positioned outside, for one-stage forming. Formability was evaluated based on the maximum forming height achieved without breaking the aluminum foil or causing lifting between the layers, according to the following criteria.

[0223] The die used had a square punch shape of 30 mm per side, a 2 mm corner radius, and a 1 mm shoulder radius. The die hole used had a 34 mm square shape, a 2 mm corner radius, and a 1 mm shoulder radius. The gap between the punch and the die hole was 2 mm per side, and this gap created a tilt corresponding to the molding height.

[0224] A: Maximum molding height is 6mm or more (good)

[0225] B: Maximum molding height is 4mm or more and less than 6mm (can be used)

[0226] C: Maximum molding height is less than 4mm (cannot be used)

[0227] [Moisture and heat resistance of molded products]

[0228] The obtained laminate was cut into pieces of 80 mm x 80 mm to prepare blanks, which were then subjected to one-stage forming using a straight die with no limitation on forming height, with the stretched polyamide film positioned outside, and stretched at a forming height of 3 mm to obtain a formed article.

[0229] The molded article was then placed in a constant temperature and humidity chamber at 85°C and 85% RH, left to stand for 168 hours, and then removed from the chamber. The presence of floating was visually checked and evaluated according to the following criteria.

[0230] The punch shape of the die used was a square with a side of 30 mm, a corner R of 2 mm, and a punch shoulder R of 1 mm. The die hole shape of the die used was a square with a side of 34 mm, a die hole corner R of 2 mm, and a die hole shoulder R of 1 mm.

[0231] A: No floating (good)

[0232] B: Floating occurs on one of the four sides (usable)

[0233] C: Floating occurs on two or more of the four sides (cannot be used)

[0234] [Resistance of molded products to external forces (external stress resistance)]

[0235] The resulting laminate was cut into 80 mm x 80 mm pieces to form blanks. These blanks were then subjected to one-stage forming using a straight die with no limit on forming height, stretching at a forming height of 3 mm, with the extended polyamide film positioned outward, to produce molded products. Ten molded products were deformed by pressing the formed portion (corner) with a finger. The presence of metal foil breakage was confirmed and evaluated according to the following criteria.

[0236] A: The number of metal foil breaks is less than one out of ten (good)

[0237] B: 2 or 3 of the 10 foils were broken (usable)

[0238] C: Four or more of the 10 metal foils were broken (unusable)

[0239]

[0240]

[0241] The abbreviations in Table 3 are as follows.

[0242] SC-1: Glycidoxypropyltrimethoxysilane

[0243] EP-1: Bisphenol A epoxy resin (trade name: JER834, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: 245 g / eq, molecular weight: approximately 470)

[0244] EP-2: Bisphenol A epoxy resin (trade name: JER1001, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight: 470 g / eq, molecular weight: approximately 900)

[0245] NCO-1: trimethylolpropane adduct of toluene diisocyanate (trade name: coronate L, manufactured by Tosoh Corporation, non-volatile matter concentration: 75% by mass, NCO content: 13.2% by mass)

[0246] The results in Table 3 show that the laminate of the present invention, which uses a hydroxyl-containing polyurethane resin (a) having a predetermined ester bond concentration as the main agent for forming the outer adhesive layer, exhibits excellent appearance, lamination strength, and moldability. Furthermore, lamination strength after the wet heat test was maintained, and the molded product exhibited excellent wet heat resistance. Furthermore, the molded portion of the molded product exhibited excellent resistance to external stress, suppressing breakage of the aluminum foil in the laminate.

[0247] In particular, in Example 10, since the ester bond concentration, urethane bond concentration, and weight average molecular weight of the polyurethane resin (a) having a hydroxyl group were within appropriate ranges, excellent results were obtained in all evaluations.

[0248] On the other hand, Comparative Example 1 corresponds to the examples of Japanese Patent Application Laid-Open No. 2019-156925 (Patent Document 3), but the ester bond concentration of the polyurethane polyol is low, resulting in reduced lamination strength. In addition, the molded article has poor resistance to moist heat and external stress.

[0249] Comparative Example 2 corresponds to the example of Japanese Patent Application Laid-Open No. 2015-024862 (Patent Document 1), but lacks a urethane bond, resulting in reduced lamination strength. Furthermore, the moldability is insufficient, and the molded product has poor resistance to moist heat and external stress.

Claims

1. A laminate for blister packaging, comprising a structure in which at least an outer resin film layer (1), an outer adhesive layer (2), a metal foil layer (3), an inner adhesive layer (4) and an inner resin film layer (5) are laminated in this order, wherein the laminate for blister packaging is characterized in that: The outer adhesive layer (2) is formed of a polyurethane adhesive containing a main agent (A) and a curing agent, wherein the main agent (A) contains a polyurethane resin (a) having a hydroxyl group, and the curing agent contains a polyisocyanate component (B). The polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol and a polyisocyanate, and has an ester bond concentration of 9.20 mmol / g to 10.50 mmol / g. 2 . The laminate for blister packs according to claim 1 , wherein the polyurethane resin (a) having a hydroxy group has a urethane bond concentration of 0.10 mmol / g to 0.90 mmol / g. 3 . The laminate for blister packs according to claim 1 , wherein the polyurethane resin (a) having a hydroxy group has a hydroxy value of 0.5 to 20 mgKOH / g. 4 . The laminate for blister packs according to claim 1 , wherein the polyurethane resin (a) having a hydroxyl group is a reaction product of a polyester polyol having a weight average molecular weight of 5,000 to 30,000 and a polyisocyanate. 5 . The laminate for blister packs according to claim 1 , wherein the polyurethane resin (a) having a hydroxy group has a weight average molecular weight of 50,000 to 100,000.

6. The laminate for blister packs according to claim 1 or 2, wherein the outer resin film layer (1) is polyamide.

7. The laminate for blister packs according to claim 1 or 2, wherein the inner resin film layer (5) is polyvinyl chloride. 8 . A blister package comprising the laminate for blister packages according to claim 1 , comprising a cover material.

9. The blister package of claim 8, wherein the cover material comprises a metal layer.

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