JP7689526B2 - Laminate for blister pack, blister pack - Google Patents

Description

The present invention relates to a laminate for blister packs and blister packs.

Blister packs (also known as press-through packaging or PTP packaging materials) have traditionally been known as containers for packaging items such as medicines, such as tablets and capsule preparations, and foods. A synthetic resin film is used as the container body of a blister pack, and aluminum foil is used as the lid material. The container body is formed with multiple pockets for individually storing tablets, etc. Synthetic resin films have good plasticity and excellent formability, so they are widely used as the material for the container body.

However, when the container body is made of a synthetic resin film, moisture can easily penetrate the tablets, causing them to deteriorate. In addition, most synthetic resin films are transparent, and the tablets can easily deteriorate when exposed to ultraviolet light. For this reason, a laminate of aluminum foil and a resin film is sometimes used as the material for the container body (Patent Documents 1 and 2).

JP 2004-058515 A Special Publication No. 2008-535746

However, this type of laminate had the problem that peeling occurred between the aluminum foil and the resin film (especially between the aluminum foil and the outer resin film) when the pockets were molded, making the laminate prone to tearing.

The present invention has been made in consideration of these circumstances, and aims to provide a laminate for blister packs and a blister pack that have excellent moisture resistance, prevent deterioration of the contents due to ultraviolet rays, and are less likely to break during molding.

That is, the present invention relates to a laminate for blister packs, which is a cured coating film of a two-component curing adhesive in which a base film, a first adhesive layer, an aluminum foil, a second adhesive layer, and a sealant layer are laminated in this order, and at least one of the first adhesive layer and the second adhesive layer comprises a polyol composition (X) containing a polyester polyol (A1) having a glass transition temperature of -30°C or more and 80°C or less, and a polyisocyanate composition (Y) containing a polyisocyanate compound (B1), in which the amount of aliphatic isocyanate in the polyisocyanate compound (B1) is 50 mass% or less, and the ratio [NCO]/[OH] of the number of moles of hydroxyl groups [OH] contained in the polyol composition (X) to the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (Y) is 0.5 or more and 20 or less, and a blister pack using the laminate.

The present invention provides a blister pack that is highly moisture-proof, inhibits deterioration of the contents due to ultraviolet rays, and is less likely to break during molding.

<Laminate for blister pack>
The blister pack laminate of the present invention is a cured coating film of a two-component curing adhesive in which a base film, a first adhesive layer, an aluminum foil, a second adhesive layer, and a sealant layer are laminated in this order, and at least one of the first adhesive layer and the second adhesive layer contains a polyol composition (X) containing a polyester polyol (A1) having a glass transition temperature of -30°C or more and 80°C or less, and a polyisocyanate compound (B1), in which the amount of aliphatic isocyanate in the polyisocyanate compound (B1) is 50 mass% or less, and the ratio [NCO]/[OH] of the number of moles of hydroxyl groups [OH] contained in the polyol composition (X) to the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (Y) is 0.5 or more and 20 or less. Hereinafter, for convenience, this adhesive will be referred to as a two-component curing adhesive (Z). In this specification, the blister pack laminate refers to a laminate used for molding a blister pack before the contents are sealed in. The configuration of the present invention will be described in detail below, taking as an example a case in which the first adhesive layer is a cured coating film of the two-component curing adhesive (Z).

(Base film)
The outer layer of the laminate of the present invention (the layer disposed on the opposite side of the aluminum foil from the contents) is made of a film having excellent puncture resistance. Specific examples of the base film include polyamide film and polyester film.

The polyamide film is not particularly limited, and conventionally known films can be used. For example, homopolymers such as poly(4-aminobutyric acid) (nylon 4), poly(6-aminohexanoic acid) (nylon 6, also poly(caprolactam)), poly(7-aminoheptanoic acid) (nylon 7), poly(8-aminooctanoic acid) (nylon 8), poly(9-aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid) (nylon 10), poly(11-aminoundecanoic acid) (nylon 11), and poly(12-aminododecanoic acid) (nylon 12) can be used. adipamide) [nylon 6,6], poly(hexamethylene sebacamide) [nylon 6,10], poly(heptamethylene pimelamide) [nylon 7,7], poly(octamethylene suberamide) [nylon 8,8], poly(hexamethylene azelamide) [nylon 6,9], poly(nonamethylene azelamide) [nylon 9,9], poly(decamethylene azelamide) [nylon 10,9], poly(tetramethylene diamine-co-oxalic acid) [nylon 4,2], polyamides of n-dodecanedioic acid and hexamethylene diamine [nylon 6,12], dodecamethylene diamine and Polyamide of n-dodecanedioic acid [nylon 12,12], caprolactam/hexamethylene adipamide copolymer [nylon 6,6/6], hexamethylene adipamide/caprolactam copolymer [nylon 6/6,6], trimethylene adipamide/hexamethylene azelaamide copolymer [nylon trimethyl 6,2/6,2], hexamethylene adipamide-hexamethylene-azelaamide caprolactam copolymer [nylon 6,6/6,9/6], poly(tetramethylene diamine-co-isophthalic acid) [nylon 4,I], polyhexamethylene isophthalamide Examples of the polyamide copolymer include [nylon 6,1], hexamethylene adipamide/hexamethylene-isophthalamide [nylon 6,6/6I], hexamethylene adipamide/hexamethylene terephthalamide [nylon 6,6/6T], poly(2,2,2-trimethylhexamethylene terephthalamide), poly(m-xylylene adipamide) [MXD6], poly(p-xylylene adipamide), poly(hexamethylene terephthalamide), poly(dodecamethylene terephthalamide), polyamide 6T/6I, polyamide 6/MXDT/I, and polyamide MXDI. Nylon 6, nylon 6,6, nylon 6/6,6, or mixtures thereof are preferred.

Examples of polyester films include polyethylene terephthalate and glycol-modified polyethylene terephthalate.

The thickness of the substrate film is not particularly limited, but from the viewpoint of the balance between formability and puncture resistance, it is preferably from 10 μm to 50 μm, and more preferably from 20 μm to 45 μm.
The substrate film is produced by a tubular method or a tenter method, and is produced by biaxial stretching. The stretching method may be simultaneous biaxial stretching or sequential biaxial stretching.

(Aluminum foil)
The aluminum foil may be a soft material made of pure aluminum or an aluminum-iron alloy. Specific examples of the alloy include alloy numbers 8079 and 8021. The thickness of the aluminum foil may be adjusted as appropriate, but is preferably 15 μm to 80 μm, and more preferably 20 μm to 60 μm, from the viewpoint of the balance between formability and moisture resistance.

The aluminum foil may be chemically treated on one or both surfaces. Examples of chemical treatments include undercoat treatment using a coupling agent such as a silane coupling agent or a titanium coupling agent, and chromate treatment. An example of a chromate treatment is a method in which a composition containing, for example, phosphoric acid, at least one of chromate and chromic acid (III) salt, and at least one selected from the group consisting of a metal salt of fluoride, a non-metal salt of fluoride, an acrylic resin, a chitosan derivative resin, and a phenolic resin is applied to the surface of the aluminum foil that has been degreased, and then dried.

(Sealant Layer)
The sealant layer may be any one of a polypropylene film, a polyvinyl chloride film, and a polyvinylidene chloride film. The thickness of the sealant layer is, for example, from 20 μm to 150 μm in view of the balance between heat sealability and moldability.

(First Adhesive Layer)
The first adhesive layer is a cured coating film of the two-component curing adhesive (Z). The first adhesive layer is disposed between the polyamide film and the aluminum foil, and also serves to bond them together.

The glass transition temperature of the polyester polyol (A1) is −30° C. or higher and 80° C. or lower. The glass transition temperature is measured as follows.
Using a differential scanning calorimeter (DSC-7000 manufactured by SII Nano Technology Co., Ltd., hereinafter referred to as DSC), 5 mg of the sample is heated from room temperature to 200 ° C. at 10 ° C. / min under a nitrogen flow of 30 mL / min, and then cooled to -80 ° C. at 10 ° C. / min. The temperature is again raised to 150 ° C. at 10 ° C. / min to measure the DSC curve, and the intersection of the straight line extending the baseline on the low temperature side in the measurement results observed in the second heating process to the high temperature side and the tangent drawn at the point where the gradient of the curve of the step-like part of the glass transition is maximum is taken as the glass transition point, and the temperature at this time is taken as the glass transition temperature. In addition, the temperature is raised to 200 ° C. in the first heating, but this may be a temperature at which the polyester polyol (A1) is sufficiently melted, and if 200 ° C. is insufficient, it is adjusted appropriately. Similarly, if the cooling temperature is insufficient at -80 ° C. (e.g., if the glass transition temperature is lower), it is adjusted appropriately.

Since the glass transition temperature of the polyester polyol (A1) is within the above range, it is possible to obtain a laminate for blister packs that has an excellent balance between the wettability of the two-component curing adhesive (Z) to the substrate and the hardness of the cured coating film, and that has excellent adhesion, formability, and heat resistance.

Polyester polyol (A1) is a reaction product of a composition containing a polybasic acid or its derivative and a polyhydric alcohol. Examples of polybasic acids or their derivatives used in the synthesis of polyester polyols include aliphatic polycarboxylic acids such as malonic acid, ethyl malonic acid, dimethyl malonic acid, succinic acid, 2,2-dimethyl succinic acid, succinic anhydride, alkenyl succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, dimer acid, and trimer acid;

Alkyl esters of aliphatic polycarboxylic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimelate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

Alicyclic polycarboxylic acids such as 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, himic anhydride, and HET acid anhydride;

Aromatic polycarboxylic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride;

Methyl esters of aromatic polycarboxylic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate; etc., which may be used alone or in combination of two or more.

The polyhydric alcohol used to prepare the polyester polyol (A1) may be a diol or a polyol having three or more functional groups. Examples of the diol include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohexane, 2,2,4-trimethyl-1,3-pentanediol, and dimer diol;

Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol;

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

Lactone-based polyester polyols obtained by polycondensation reaction of the aliphatic diol with various lactones such as lactonoids and ε-caprolactone;

Bisphenols such as bisphenol A and bisphenol F;

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

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

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

Examples include lactone-based polyester polyols obtained by polycondensation reaction of the above-mentioned aliphatic polyols with various lactones such as ε-caprolactone.

Because of their excellent heat resistance, it is preferable that the polybasic acid contains aromatic polycarboxylic acids or alkyl esters of aromatic polycarboxylic acids (hereinafter collectively referred to as aromatic polycarboxylic acids). Of the polybasic acids, aromatic polycarboxylic acids are preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more. The entire amount of the polybasic acid may be aromatic polycarboxylic acids.

The polyester polyol (A1) may be a polyester polyurethane polyol which is a reaction product of a composition containing a polyisocyanate compound in addition to the polybasic acid and polyhydric alcohol described above. Alternatively, the polyester polyol obtained from the polybasic acid and polyhydric alcohol described above may be urethane-extended with a polyisocyanate compound to obtain a polyester polyurethane polyol. The polyisocyanate compound used in this case may be the same as the polyisocyanate compound (B1) exemplified below, and may be used alone or in combination.

The solid content hydroxyl value of polyester polyol (A1) is preferably 1.0 to 40.0 mg KOH/g, more preferably 1.0 to 30.0 mg KOH/g, and even more preferably 3.0 to 25.0 mg KOH/g, in order to provide excellent adhesive strength and a crosslinking density suitable for molding.

The solid acid value of polyester polyol (A1) is not particularly limited, but as an example, it is 10. mgKOH/g or less. The lower limit is preferably as low as possible, but from the viewpoint of reactivity, it is difficult to introduce hydroxyl groups to all ends of polyester polyol (A), and some of the ends become carboxyl groups. For this reason, the solid acid value is substantially 1.0 mgKOH/g or more, and in the case of controlled production such as reaction using an excess of polyhydric alcohol with a polybasic acid having an aromatic ring or its derivative, it is often 0.5 mgKOH/g or more. The hydroxyl value and acid value can be measured by the method described in JIS-K0070.

If the number average molecular weight (Mn) of the polyester polyol (A1) is too small, the crosslinking density may become too high, resulting in reduced moldability. It can be adjusted appropriately depending on the desired degree of moldability, but as an example, it is preferably 3,000 to 100,000, more preferably 3,500 to 50,000, more preferably 4,000 to 20,000, and more preferably 5,000 to 20,000. The weight average molecular weight (Mw) of the polyester polyol (A1) is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. In this specification, the number average molecular weight (Mn) and weight average molecular weight (Mw) are values measured by gel permeation chromatography (GPC) under the following conditions.

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

Of the solid content of the polyol composition (X), the blending amount of the polyester polyol (A1) is preferably 20% by mass or more, preferably 40% by mass or more, and more preferably 50% by mass or more. The entire solid content of the polyol composition (X) may be polyester polyol (A1). This makes it possible to more reliably obtain a laminate for a blister pack having excellent moldability.

The polyol composition (X) may contain a polyol (A2) other than the polyester polyol (A1). Examples of the polyol (A2) include polyester polyols, polycarbonate polyols, and polyoxyalkylene-modified polyols. The number average molecular weight of these polyols (A2) is, for example, 300 to 50,000. It is preferable that the amount of the polyol (A2) in the solid content of the polyol composition (X) is 20 mass% or less. In particular, by using a polyol having a glass transition temperature of 80°C (but not including 80°C) to 110°C or less in combination, the adhesive strength, moldability, and heat resistance are improved.

The polyisocyanate compound (B1) is not particularly limited as long as it is a compound having multiple isocyanate groups in one molecule. Examples of such polyisocyanate compounds (B1) include polyisocyanates having an aromatic structure in the molecular structure, such as tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and xylylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates are modified with carbodiimide;

Polyisocyanates with an alicyclic structure in the molecular structure, such as isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,3-(isocyanatomethyl)cyclohexane;

Linear aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, lysine diisocyanate, and trimethylhexamethylene diisocyanate, and compounds in which some of the NCO groups of these polyisocyanates have been modified with carbodiimide;

These include isocyanurates of these polyisocyanates; allophanates of these polyisocyanates; biuret forms of these polyisocyanates; adducts of these polyisocyanates modified with trimethylolpropane; and polyurethane polyisocyanates which are reaction products of these polyisocyanates with polyols.

The polyisocyanate compound (B1) may be one of the polyisocyanates described above or a combination of two or more of them, but the amount of aliphatic isocyanate in the polyisocyanate compound (B1) is 50% by mass or less. This allows a laminate for blister packs with excellent heat resistance to be obtained. In this specification, aliphatic isocyanate is a general term for polyisocyanates having an alicyclic structure in the molecular structure, linear aliphatic polyisocyanates, compounds in which a portion of the NCO groups of these is modified with carbodiimide, isocyanurates, allophanates, biuret bodies, adducts, and polyurethane polyisocyanates of these isocyanates.

The two-component curing adhesive (Z) may contain a coupling agent (C). This allows the adhesive to have better moldability. The effect of the coupling agent (C) is particularly effective when the aluminum foil has not been subjected to a chemical conversion treatment. Examples of the coupling agent (C) include a silane coupling agent (C1), a titanate-based coupling agent (C2), and an aluminum-based coupling agent (C3). The coupling agent (C) may be added to the polyol composition (X) or to the polyisocyanate composition (Y). It may be added when mixing the polyol composition (X) and the polyisocyanate composition (Y).

Examples of the silane coupling agent (C1) include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and glycidoxyoctyltrimethoxysilane; vinyltris(β-methoxy Examples of the silane coupling agents include vinyl silanes such as triethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, octenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane; polymeric epoxysilanes having a plurality of alkoxysilyl groups and a plurality of epoxy groups introduced into a polymer backbone, and polymeric aminosilanes having a plurality of alkoxysilyl groups and a plurality of amino groups introduced into a polymer backbone; hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane, and 3-isocyanatepropyltriethoxysilane. These silane coupling agents (C1) can be used alone or in combination of two or more kinds.

Examples of titanate-based coupling agents (C2) include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, tetrastearoxytitanium, etc.

Examples of aluminum-based coupling agents (C3) include acetoalkoxyaluminum diisopropylate, etc.

The amount of coupling agent (C) is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.7 parts by mass or more, per 100 parts by mass of the solid content of polyol composition (X). This makes it possible to more reliably improve moldability. In addition, since the degree of improvement in moldability decreases when the content of coupling agent (C) exceeds a certain amount, there is no particular restriction, but it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the solid content of polyol composition (X).

The two-component curing adhesive (Z) may contain an epoxy resin. When the two-component curing adhesive (Z) contains an epoxy resin, a laminate having excellent moldability and initial adhesive strength can be obtained.

Examples of epoxy resins include bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins; biphenyl type epoxy resins such as biphenyl type epoxy resins and tetramethylbiphenyl type epoxy resins; dicyclopentadiene-phenol addition reaction type epoxy resins, etc. It is preferable to use an epoxy resin having a number average molecular weight (Mn) of 300 to 2,000. It is also preferable to use an epoxy resin having an epoxy equivalent of 150 to 1,000 g/equivalent.
The amount of the epoxy resin is preferably 30 mass % or less of the solid content of the polyol composition (X).

The two-component curing adhesive (Z) may contain a tackifier. The tackifier may be added to the polyol composition (X), the polyisocyanate composition (Y), or when they are mixed. Examples of tackifiers include rosin-based or rosin ester-based tackifiers, terpene-based or terpene phenol-based tackifiers, saturated hydrocarbon resins, coumarone-based tackifiers, coumarone-indene-based tackifiers, styrene resin-based tackifiers, xylene resin-based tackifiers, phenol resin-based tackifiers, and petroleum resin-based tackifiers. These may be used alone or in combination of two or more. Tackifiers with various softening points can be obtained mainly depending on the molecular weight, but it is preferable that the softening point is 50 to 160°C in terms of compatibility when mixed with other resins constituting the polyol composition (X), color tone, thermal stability, and the like. The polyol composition (X) is used in an amount of 1 to 30 parts by mass (solid content) relative to 100 parts by mass of the solid content of the resin constituting the polyol composition (X), and preferably in an amount of 3 to 20 parts by mass, and particularly preferably in an amount of 5 to 20 parts by mass (solid content).

The two-component curing adhesive (Z) may contain phosphoric acid or a derivative thereof. This improves the initial adhesion and suppresses problems such as tunneling. The phosphoric acid or a derivative thereof may be added to the polyol composition (X) or to the polyisocyanate composition (Y). It may be added when these are mixed.

Examples of phosphoric acids or derivatives thereof include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphoric acid; condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid; monomethyl orthophosphate, monoethyl orthophosphate, monopropyl orthophosphate, monobutyl orthophosphate, mono-2-ethylhexyl orthophosphate, monophenyl orthophosphate, monomethyl phosphite, monoethyl phosphite, monopropyl phosphite, monobutyl phosphite, mono-2-ethylhexyl phosphite, monophenyl phosphite, diphenyl orthophosphate, Examples of such mono- and diesters include monoesters and diesters of condensed phosphoric acid and alcohols, monoesters and diesters of condensed phosphoric acid and alcohols, for example, products obtained by adding an epoxy compound such as ethylene oxide or propylene oxide to the above-mentioned phosphoric acids, and epoxy phosphoric acid esters obtained by adding the above-mentioned phosphoric acids to aliphatic or aromatic diglycidyl ethers, and two or more of these can also be used in combination.

The two-component curing adhesive (Z) may contain a ketone resin. The ketone resin is a resin obtained by reacting a ketone compound with an aldehyde in the presence of an alkaline catalyst. Examples of the ketone compound include cyclohexanone, methylcyclohexanone, acetophenone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the aldehyde include formaldehyde, acetaldehyde, n-butyl aldehyde, isobutyl aldehyde, valerianaldehyde, and dodecanal.

When the two-component curing adhesive (Z) contains a ketone resin, peeling between the base film and the aluminum foil, and between the sealant layer and the aluminum foil is suppressed, and a laminate for blister packs with excellent formability can be obtained.
The amount of the ketone resin to be blended is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the above-mentioned polyester polyol (A1).

The two-component curing adhesive (Z) may be in the form of either a solvent-based or solventless type. In the case of a solvent-based adhesive, at least one of the polyol composition (X) and the polyisocyanate composition (Y) contains an organic solvent such as esters such as ethyl acetate, butyl acetate, cellosolve acetate, etc., ketones such as acetone, methyl ethyl ketone, isobutyl ketone, cyclohexanone, etc., ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, dimethyl sulfoxide, dimethyl sulfamide, etc., and the above-mentioned components are dissolved in the organic solvent. These organic solvents may be used as they are as reaction media during the production of the above-mentioned components, or may be added separately.

In the case of a solventless adhesive, it does not substantially contain any of the organic solvents listed above. Note that if the organic solvent used as a reaction medium during the production of each component of the adhesive is not completely removed and remains, it is considered to not substantially contain any organic solvent.

In the case of solventless adhesives, low viscosity is important because of the characteristic that the viscosity decreases when heated, and the molecular weight and molecular structure of the polyester polyol (A1) and the polyisocyanate compound (B1) that can be used are limited. If the structure derived from aromatic polycarboxylic acid incorporated in the polyester polyol (A1) increases, or if the polyisocyanate compound (B1) has an aromatic ring, the viscosity increases and the coating suitability tends to decrease in order to make it a solventless adhesive. For this reason, a solvent-based adhesive is preferable.

In addition, the two-component adhesive (Z) may contain various additives such as ultraviolet absorbers, antioxidants, silicone-based additives, fluorine-based additives, rheology control agents, defoamers, antistatic agents, and anti-fogging agents.

The polyol composition (X) and the polyisocyanate composition (Y) are used in such a manner that the ratio [NCO]/[OH] of the total number of moles of hydroxyl groups contained in the polyol composition (X) [OH] to the number of moles of isocyanate groups contained in the polyisocyanate composition (Y) [NCO] is in the range of 0.5 to 20. This allows a laminate for blister packs with excellent moldability to be obtained. In order to obtain a more excellent initial adhesive strength, [NCO]/[OH] is preferably 0.8 to 15, and more preferably 0.8 to 10.

When the [NCO]/[OH] ratio is high, excess isocyanate compound reacts with moisture in the atmosphere to form urea bonds, improving heat resistance, but the cured coating film tends to become hard and moldability tends to decrease.
If the [NCO]/[OH] ratio is too low, the crosslink density will be low, and the heat resistance will be reduced. Also, the amount of the polyisocyanate compound (B1) in the two-component curing adhesive (Z) will inevitably be small, making it difficult for the two-component curing adhesive (Z) to sufficiently wet and spread over the substrate during aging, which may result in a decrease in adhesive strength.

From the viewpoint of the balance between adhesion and moldability, the thickness of the first adhesive layer is preferably 0.5 μm or more and 50 μm or less, and more preferably 2 μm or more and 30 μm or less.

(Second Adhesive Layer)
The second adhesive layer is a layer disposed between the aluminum foil and the sealant layer to bond them together. The second adhesive layer is a cured coating of an adhesive, and the adhesive used is not particularly limited as long as it is suitable for bonding the aluminum foil and the above-mentioned film. For example, a general-purpose two-component curing adhesive made of a polyol compound and a polyisocyanate compound, or a two-component curing adhesive made of an acid-modified polyolefin and a curing agent capable of reacting with it can be used.

From the viewpoint of the balance between adhesion and moldability, the thickness of the second adhesive layer is preferably 0.5 μm or more and 50 μm or less, and more preferably 2 μm or more and 30 μm or less.

(Modification)
Although the above description has been given with reference to an example in which the first adhesive layer is a two-component curing adhesive (Z), the laminate for blister packs of the present invention may have a first adhesive layer that is a general-purpose two-component curing adhesive made of a polyol compound and a polyisocyanate compound, or a two-component curing adhesive made of an acid-modified polyolefin and a curing agent capable of reacting with the same, and the second adhesive layer may be a cured coating film of the two-component curing adhesive (Z). Both the first adhesive layer and the second adhesive layer may be a cured coating film of the two-component curing adhesive (Z). It is preferable that the first adhesive layer is a cured coating film of the two-component curing adhesive (Z) because of its superior moldability and heat resistance, and it is more preferable that both the first adhesive layer and the second adhesive layer are cured coating films of the two-component curing adhesive (Z).

(Method of manufacturing laminate for blister pack)
The method for producing the laminate for blister packs of the present invention is not particularly limited, but as an example, when the two-component curing adhesive (including the two-component curing adhesive (Z)) is a solvent-based adhesive, it is produced by the following method. First, the above-mentioned two-component curing adhesive is applied to either the base film or the aluminum foil by extrusion, gravure coating, roll coating, or the like, and the organic solvent is evaporated, and then the other is laminated. Next, the two-component curing adhesive is applied to the aluminum foil, the organic solvent is evaporated, and then a sealant layer is laminated, and aging is performed at room temperature to 90° C. for 2 days to 2 weeks to cure the adhesive, thereby obtaining the laminate for blister packs of the present invention. Alternatively, aging may be performed under the above-mentioned conditions after laminating the base film and the aluminum foil, and aging may be further performed after laminating the aluminum foil and the sealant layer.

When the adhesive is a solventless type, for example, a two-component curing adhesive is applied to either the base film or the aluminum foil, and then the base film and the aluminum foil are laminated together and aged for 2 days to 2 weeks at room temperature to 90°C. Next, the two-component curing adhesive is applied to the aluminum foil, the aluminum foil and the sealant layer are laminated together, and aging is performed under the same conditions to cure the adhesive, thereby obtaining the laminate for blister packs of the present invention.

<Blister pack>
The blister pack of the present invention is obtained by molding the laminate for blister packs described above. The laminate for blister packs of the present invention may be molded to have one or more pockets and then laminated with a conventionally known lid material for blister packs (for example, aluminum foil coated with a heat seal agent), or the blister pack may be prepared by preparing two laminates for blister packs of the present invention each having one or more pockets, matching the pockets, and heat sealing the heat seal layers together.
Examples of the molding method include flat plate air pressure molding, plug-assisted air pressure molding, drum vacuum molding, and plug molding.

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

<Synthesis of polyester polyol>
(Synthesis Example 1) Synthesis of polyester polyol (A1-1) 1102 parts of isophthalic acid, 473 parts of terephthalic acid, 1070 parts of 1,6-hexanediol, 156 parts of neopentyl glycol, and 0.46 parts of an organic titanium compound ("Orgatics TC-100" manufactured by Matsumoto Fine Chemical Co., Ltd.) were charged into a flask equipped with a stirring rod, a temperature sensor, and a distillation tube, and dry nitrogen was introduced into the flask while stirring, and the temperature was raised to 240° C. while distilling off the generated water. Thereafter, an esterification reaction was carried out while increasing the degree of vacuum to 30 torr, and the reaction was stopped when the resin acid value became 2.00 mgKOH/g or less. After cooling to 150°C, the mixture was diluted with a mixed solution of ethyl acetate and toluene (mixing ratio 1:1) to a resin solid content of 50%, thereby obtaining a polyester polyol (A1-1') having a number average molecular weight (Mn) of 4,000, a weight average molecular weight (Mw) of 9,700, a resin hydroxyl value (solid content equivalent) of 38.8 mgKOH/g, a resin acid value (solid content equivalent) of 0.63 mgKOH/g, and a glass transition temperature (Tg) of 2.8°C.

A flask equipped with a stirring rod, temperature sensor, and condenser was charged with 1,000 parts of the polyester polyol (A1-1'), 25.7 parts of hexamethylene diisocyanate ("Desmodur H" manufactured by Sumika Covestro Urethane Co., Ltd.), and 0.16 parts of an organotin compound ("Neostan U-130" manufactured by Nitto Kasei Co., Ltd.), and dry nitrogen was introduced into the flask and the mixture was heated to 75-78°C with stirring to carry out a chain extension reaction. The reaction was stopped when the isocyanate weight percentage reached 0.05% or less, and the mixture was diluted with a mixed solvent of ethyl acetate and toluene (mixing ratio 1:1) to a resin solid content of 50%, yielding a polyester polyol (A1-1) having a number average molecular weight (Mn) of 11,000, a weight average molecular weight (Mw) of 50,000, a resin hydroxyl value (solid content equivalent) of 3.9 mgKOH/g, a resin acid value (solid content equivalent) of 1.06 mgKOH/g, and a glass transition temperature (Tg) of 7.1°C.

Synthesis Example 2 Synthesis of Polyester Polyol (A1-2) 1,261 parts of isophthalic acid, 540 parts of terephthalic acid, 667 parts of 1,6-hexanediol, 182 parts of neopentyl glycol, 253 parts of ethylene glycol, and 0.5 parts of an organic titanium compound ("Orgatix TC-100" manufactured by Matsumoto Fine Chemical Co., Ltd.) were charged into a flask equipped with a stirring rod, a temperature sensor, and a rectification tube, and dry nitrogen was introduced into the flask with stirring, and the temperature was raised to 240° C. while distilling off the generated water. Thereafter, an esterification reaction was carried out while increasing the degree of vacuum to 30 torr. When the resin acid value became 2.00 mgKOH/g or less, the reaction was stopped. After cooling to 150°C, the mixture was diluted with a mixed solution of ethyl acetate and toluene (mixing ratio 1:1) to a resin solid content of 50%. A polyester polyol (A1-2) having a number average molecular weight (Mn) of 6,700, a weight average molecular weight (Mw) of 17,000, a resin hydroxyl value (solid content equivalent) of 17.2 mgKOH/g, a resin acid value (solid content equivalent) of 1.58 mgKOH/g, and a glass transition temperature (Tg) of 23.6°C was obtained.

(Synthesis Example 4) Polyester polyol (A1-3)
A flask equipped with a stirring rod, a temperature sensor, and a rectification tube was charged with 790.8 parts of isophthalic acid, 339.4 parts of terephthalic acid, 20.0 parts of trimellitic anhydride, 738.0 parts of 1,6-hexanediol, 107.4 parts of neopentyl glycol, and 4.0 parts of an organic titanium compound ("Orgatix TC-100" manufactured by Matsumoto Fine Chemical Co., Ltd.), and dry nitrogen was introduced into the flask, and the mixture was heated to 230-240°C with stirring to carry out an esterification reaction. The reaction was stopped when the resin acid value reached 1.50 mgKOH/g or less, and the mixture was cooled to 150°C and then diluted with ethyl acetate to a resin solids content of 58%. A polyester polyol (A1-3) having a number average molecular weight (Mn) of 7,000, a weight average molecular weight (Mw) of 23,500, a resin hydroxyl value (solid content equivalent) of 22.4 mgKOH/g, a resin acid value (solid content equivalent) of 1.26 mgKOH/g, and a glass transition point (Tg) of 7.3°C was obtained.

(Synthesis Example 5) Polyester polyol (A2-1)
A flask equipped with a stirring rod, a temperature sensor, and a rectification tube was charged with 164 parts of neopentyl glycol, 1,125 parts of 1,6-hexanediol, 351 parts of terephthalic acid, 351 parts of isophthalic acid, 928 parts by weight of adipic acid, and 0.89 parts by weight of an organic titanium compound. Dry nitrogen was introduced into the flask with stirring, and the temperature was raised to 240° C. while distilling off the generated water. Thereafter, an esterification reaction was carried out while increasing the degree of vacuum to 30 torr. The reaction was stopped when the resin acid value became 2.00 mgKOH/g or less. After cooling to 150°C, the mixture was diluted with ethyl acetate to a resin solids content of 60% to obtain a polyester polyol (A2-1) having a number average molecular weight (Mn) of 5,200, a weight average molecular weight (Mw) of 32,000, a resin hydroxyl value (solid content equivalent) of 6.6 mgKOH/g, a resin acid value (solid content equivalent) of 1.86 mgKOH/g, and a glass transition temperature (Tg) of -43.6°C.

(Synthesis Example 6) Polyester polyol (A2-2)
A flask having a stirring rod, a temperature sensor, and a rectifying tube was charged with 73 parts of ethylene glycol, 223 parts of 1,2-propylene glycol, 697 parts of terephthalic acid, and 0.89 parts of an organic titanium compound, and dry nitrogen was flowed into the flask while stirring, and the temperature was raised to 240 ° C. while distilling off the generated water. Thereafter, an esterification reaction was carried out while increasing the vacuum degree to 30 torr, and the reaction was stopped when the resin acid value became 2.00 mg KOH / g or less, and after cooling to 150 ° C., the mixture was diluted with ethyl acetate to a resin solid content of 30%, and a polyester polyol (A2-2) having a number average molecular weight (Mn) of 8,400, a weight average molecular weight (Mw) of 61,300, a resin hydroxyl value (solid content equivalent) of 5.0 mg KOH / g, a resin acid value (solid content equivalent) of 4.0 mg KOH / g, and a glass transition temperature (Tg) of 84 ° C. was obtained.

<Preparation of two-component curing adhesive>
Example 1
KBM-403 (a silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd., non-volatile content: 100%) was added to polyester polyol (A1-1) so as to obtain the composition (solid content) shown in Table 1, and the mixture was thoroughly stirred until the KBM-403 was completely dissolved. To this was added a trimethylolpropane adduct of toluene diisocyanate (referred to as TDI-TMP in the table; NCO %: 13.3) and ethyl acetate so that the non-volatile content was 25%, and the mixture was thoroughly stirred to produce the two-component curing adhesive of Example 1.

(Example 2) to (Example 5), (Comparative Example 1) to (Comparative Example 4)
A two-component curing adhesive was prepared in the same manner as in Example 1, except that the polyester polyol used and the amount (solid content) were changed as shown in Tables 1 and 2. Among the compounds in the table, those not explained above are summarized as follows. [NCO]/[OH] is rounded off to one decimal place.
(TEGO Variplus AP)
Manufactured by EVONIC, ketone-aldehyde condensation resin, hydroxyl value: 5 mg KOH/g
(E402-80E)
Duranate E402-80E, manufactured by Asahi Kasei Corporation, adduct of hexamethylene diisocyanate, NCO%: 9.5%

<Production of laminate for blister pack>
Example 1
The adhesive of Example 1 was applied to the matte side of an aluminum foil having a thickness of 30 μm using a dry laminator at 4 g/m ² (solid content), the solvent was evaporated, and then a stretched polyamide film having a thickness of 25 μm was laminated. Next, the adhesive of Example 1 was applied to the glossy side of the aluminum foil using a dry laminator at 4 g/m ² , the solvent was evaporated, and then a non-stretched polypropylene film having a thickness of 40 μm was laminated, and the laminate was aged at 60° C. for 5 days to harden the adhesive, thereby obtaining the laminate of Example 1.

(Example 2) to (Example 5), (Comparative Example 1) to (Comparative Example 4)
Laminates were obtained in the same manner as in Example 1, except that the adhesive of Example 1 was replaced with the adhesives of Examples 2 to 5 and Comparative Examples 1 to 4.

<Evaluation>
(Adhesive strength)
The adhesive strength between the polyamide film and the aluminum foil was evaluated using an Autograph AGS-J made by Shimadzu Corporation under the conditions of a peel speed of 50 mm/min, a peel width of 15 mm, and a peel form of 180° peeling. A higher value indicates a more suitable laminate for a blister pack.

(Moldability)
Using a "1 ton tabletop servo press (SBN-1000)" manufactured by Yamaoka Seisakusho Co., Ltd., the laminate for blister pack of the Example or Comparative Example was cut to a size of 60 x 60 mm. The polyamide film was made to be the convex side, and the molding height was set to 3.5 mm using a straight mold with a free molding height, and the moldability was evaluated based on the presence or absence of breakage of the aluminum foil and lifting between each layer. The punch shape of the mold used was a square with one side of 30 mm, a corner R of 2 mm, and a punch shoulder R of 1 mm, and the die hole shape of the mold used was a square with one side of 34 mm, a die hole corner R of 2 mm, a die hole shoulder R: 1 mm, and the clearance between the punch and the die hole was 0.3 mm on one side. The clearance causes a slope according to the molding height.
◯: No breakage of the aluminum foil or lifting between the layers, excellent for practical use △: Pinholes were observed in the aluminum foil, but there was no breakage of the aluminum foil or lifting between the layers, and it was within the practical range ×: The aluminum foil was largely broken, or lifting occurred between the layers

(heat resistance)
The laminate of the example or comparative example was cut to a size of 60 x 60 mm, and the polyamide film was placed on the outside, and the laminate was bulged at a molding height of 3.0 mm using a free-form straight mold. A heat seal bar was applied to the flange of the resulting 30 mm square tray at 190 ° C for 3 seconds so as to contact the side wall, and the appearance near the boundary between the flange and the side wall on each side was confirmed, and it was evaluated whether or not there was any lift between the stretched polyamide film and the aluminum foil. Two samples were prepared, and a total of eight sides were checked, and the evaluation was made on a three-level scale as follows.
○: No lifting (excellent for practical use)
△: Lifting occurs on 1 to 4 of the 8 sides (practical range)
×: Lifting occurs on 5 to 8 of the 8 sides

Claims (9)

A base film, a first adhesive layer, an aluminum foil, a second adhesive layer, and a sealant layer are laminated in this order,
At least one of the first adhesive layer and the second adhesive layer contains a polyester polyol (A1) having a glass transition temperature of -30°C or more and 80°C or less and an acid value of 10 mgKOH/g or less, a polyol composition (X) that does not contain an epoxy resin , and a polyisocyanate composition (Y) that contains a polyisocyanate compound (B1), the amount of aliphatic isocyanate in the polyisocyanate compound (B1) is 50 mass% or less, the polyisocyanate compound (B1) is a trimethylolpropane adduct of toluene diisocyanate, and the ratio [NCO]/[OH] of the number of moles of hydroxyl groups [OH] contained in the polyol composition (X) to the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (Y) is 0.5 or more and 20 or less. A laminate for blister packs. The laminate for blister packs according to claim 1, wherein the polyol composition (X) further contains a polyol (A2) having a glass transition temperature of 80°C (but not including 80°C) to 110°C or less, and the amount of polyester polyol (A1) in the solid content of the polyol composition (X) is 20 mass% or more. The laminate for blister packs according to claim 1 or 2, wherein the polyester polyol is a reaction product of a composition containing a polybasic acid or a derivative thereof and a polyhydric alcohol, and 30% by mass or more of the polybasic acid or a derivative thereof is an aromatic polycarboxylic acid. The laminate for blister packs according to any one of claims 1 to 3, wherein the first adhesive layer is a cured coating film of the two-component curing adhesive. The laminate for blister packs according to any one of claims 1 to 4, wherein the second adhesive layer is a cured coating film of the two-component curing adhesive. The laminate for blister packs according to any one of claims 1 to 5, wherein the two-component curing adhesive contains a coupling agent (C). The laminate for blister packs according to any one of claims 1 to 6, wherein the base film is either a polyamide film or a polyester film. The laminate for blister packs according to any one of claims 1 to 7, wherein the sealant layer is a polypropylene film, a polyvinyl chloride film, or a polyvinylidene chloride film. A blister pack formed by molding the laminate for blister packs according to any one of claims 1 to 8.