Sheets for pharmaceutical packaging, base materials for press-through packages, and press-through packages

Abstract

To provide a new medicine packaging sheet capable of enhancing moldability, and capable of suitably molding even a recess part with a small diameter such as a pocket part at a bottom material of PTP, regarding the medicine packaging sheet which includes a polyvinylidene chloride resin layer.SOLUTION: A medicine packaging sheet includes a constitution in which a base material layer (I) whose main component resin is thermoplastic resin, a polyvinylidene chloride resin layer (II) whose main component resin is polyvinylidene chloride resin, and a polyolefin resin layer (III) whose main component resin is polyolefin resin are laminated in this order. A thickness of the base material layer (I) is larger than a thickness of the polyolefin resin layer (III).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a packaging sheet suitable for manufacturing a packaging material for packaging pharmaceuticals, such as a press-through package (also referred to as "PTP"), a bottom material for PTP using the sheet, and a PTP.

Background Art

[0002] In the field of packaging pharmaceuticals and the like, a press-through package (PTP) is known as a packaging material for packaging pharmaceuticals such as capsules and tablets. PTP is, for example, after heating a transparent sheet, by performing pressure air forming, vacuum forming, plug forming, etc., a large number of pocket parts for storing solids such as capsules and tablets are formed in the sheet surface. After storing capsules etc. in each pocket part, it is a form of packaging in which a foil or film made of a material that can be easily torn or opened by hand, such as aluminum foil, is bonded as a lid material and integrated. With PTP, solids and foods etc. stored in the pockets of the transparent sheet can be directly visually confirmed with the naked eye before opening. When opening, by pressing the solid in the pocket part with a finger to break the lid material, the contents can be easily taken out.

[0003] As a raw material for the sheet used in PTP, polyvinyl chloride-based resin (hereinafter also referred to as "PVC") has been conventionally used because it has good thermoformability, rigidity at room temperature, impact resistance, and transparency. However, since the sheet using PVC may not have sufficient moisture resistance, when packaging contents that require higher moisture resistance, polypropylene-based resin (hereinafter also referred to as "PP") has been used as an alternative to PVC (see Patent Document 1).

[0004] However, in recent years, further improvement in moisture resistance has been required, and polyvinylidene chloride-based resin (PVDC) has attracted attention as a material for pharmaceutical packaging sheets.

[0005] Regarding pharmaceutical packaging sheets using polyvinylidene chloride (PVDC) as a raw material, for example, Patent Document 2 discloses a multilayer sheet for PTP, which has a polyvinyl chloride resin (A) layer as a base material and a polyvinylidene chloride resin (B) layer laminated on at least one surface of the base material, wherein the polyvinylidene chloride resin (B) layer consists of one (B)-1 layer and one (B)-2 layer, each of which is laminated on the base material in sets of at least one set, the thickness ratio of the next set to be laminated to the set closest to the base material is in the range of 0.3 to 0.75, and the thickness of the (B)-1 layer and (B)-2 layer of the set closest to the base material is in the range of 7 to 20 μm each.

[0006] Patent Document 3 discloses a multilayer sheet for PTP, which has at least three layers: a layer (I) made of a thermoplastic resin, a layer (II) made of a polyvinylidene chloride resin, and a topcoat layer (III) containing a fibrous material with a thickness of 0.15 to 5 μm, and is laminated in the order of (I) / (II) / (III), characterized in that the static friction coefficient measured in accordance with JIS K7125 with the surfaces of layer (III) facing each other is less than 0.8. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 4907115 [Patent Document 2] Japanese Patent Publication No. 2018-43507 [Patent Document 3] Patent No. 6589590 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] For packaging materials used to package pharmaceuticals, particularly high moisture resistance, or water vapor barrier properties, are required. Therefore, sheets equipped with a layer primarily composed of polyvinylidene chloride resin (PVDC) (referred to as a "polyvinylidene chloride resin layer"), as described in Patent Documents 2 and 3 above, are attracting attention as pharmaceutical packaging sheets. However, polyvinylidene chloride (PVDC) resins have high crystallinity, making them brittle and susceptible to deformation such as bending, which presents challenges in terms of moldability. Therefore, single-layer sheets made of polyvinylidene chloride resin were unsuitable for molding small-diameter recesses, such as the pockets in the bottom material of PTP (Press-Through Packaging).

[0009] Therefore, the present invention relates to a pharmaceutical packaging sheet having a polyvinylidene chloride resin layer, and aims to provide a new pharmaceutical packaging sheet that can be molded to improve moldability, and can be suitably molded even to small diameter recesses, such as the pocket portion in the bottom material of PTP. [Means for solving the problem]

[0010] The present invention proposes a pharmaceutical packaging sheet having a structure in which a base layer (I) mainly composed of a thermoplastic resin, a polyvinylidene chloride resin layer (II) mainly composed of a polyvinylidene chloride resin, and a polyolefin resin layer (III) mainly composed of a polyolefin resin are laminated in this order, wherein the thickness of the base layer (I) is greater than the thickness of the polyolefin resin layer (III).

[0011] The present invention also proposes a bottom material for PTP using the above-mentioned pharmaceutical packaging sheet. In such a bottom material for PTP, it is preferable that the polyolefin resin layer (III) is arranged to form the inner surface of the recess that constitutes the pocket portion.

[0012] The present invention also proposes a PTP comprising the above-mentioned bottom material and lid material. [Effects of the Invention]

[0013] The pharmaceutical packaging sheet proposed by the present invention has a polyvinylidene chloride resin layer (II), and therefore can have high moisture resistance, i.e., water vapor barrier properties. Furthermore, because the polyvinylidene chloride resin layer (II) is sandwiched between a base layer (I) mainly composed of a thermoplastic resin and a polyolefin resin layer (III) mainly composed of a polyolefin resin, moldability can be improved, and even small-diameter recesses, such as the pocket portion in the bottom material of a PTP pack, can be suitably molded. Therefore, for example, a bottom material for a PTP pack with a recess constituting a pocket portion can be suitably manufactured. [Modes for carrying out the invention]

[0014] Next, an example of an embodiment of the present invention will be described. However, the present invention is not limited to the embodiments described below.

[0015] <<Hand-made sheet>> A sheet according to an example of an embodiment of the present invention (referred to as the "present invention sheet") has a structure in which a base layer (I) mainly composed of a thermoplastic resin, a polyvinylidene chloride resin layer (II) mainly composed of a polyvinylidene chloride resin, and a polyolefin resin layer (III) mainly composed of a polyolefin resin are laminated in this order. While a base layer (I) primarily composed of thermoplastic resin lacks sufficient water vapor barrier properties, the addition of a polyvinylidene chloride resin layer (II) can significantly enhance water vapor barrier capabilities. Furthermore, by laminating a polyolefin resin layer (III) on the back side of the polyvinylidene chloride resin layer (II), moldability and slipperiness can be improved.

[0016] In this specification, in the sheet of the present invention, the side with the base material layer (I) will be referred to as the front side, and the opposite side, i.e., the side with the polyolefin resin layer (III), will be referred to as the back side. In addition, the "main component resin" of each layer means the resin with the highest mass ratio among the resins constituting each layer. For example, it is assumed that the resin occupies 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass of the resins constituting each layer.

[0017] The sheet of the present invention may have a structure in which the base material layer (I), the polyvinylidene chloride resin layer (II), and the polyolefin resin layer (III) are laminated in this order. For example, between the base material layer (I) and the polyvinylidene chloride resin layer (II), between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III), on the front side of the base material layer (I), on the back side of the polyolefin resin layer (III), etc., "other layers" may be provided. For example, as will be described later, an anchor coat layer (B) can be provided between the base material layer (I) and the polyvinylidene chloride resin layer (II). Also, an anchor coat layer (A) can be provided between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III). However, it is not limited to these configurations.

[0018] <Base material layer (I)> The base material layer (I) is a layer having a thermoplastic resin as the main component resin. By having such a base material layer (I), the moldability can be improved even in a sheet having a polyvinylidene chloride resin layer (II).

[0019] (Thermoplastic resin) As the thermoplastic resin which is the main component resin of the base material layer (I), conventionally known and generally used resins can be used, and it is not particularly limited. Specifically, polyvinyl chloride resins, polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polycarbonate resins, acrylic resins, fluorine-based resins such as polychlorotrifluoroethylene, polyvinyl alcohol-based resins such as ethylene-vinyl alcohol copolymers, etc. can be mentioned. These thermoplastic resins may be used alone or in combination of two or more. Among them, in the present invention, from the viewpoint of versatility, polyvinyl chloride resins or polyolefin resins are mentioned as preferable resins, and from the viewpoints of moisture resistance and environmental aspects in particular, polyolefin resins are preferably used.

[0020] (Polyolefin resin) Examples of the polyolefin resin as the main component resin of the base material layer (I) include, for example, polyethylene resins, polypropylene resins, polybutene resins, poly-4-methylpentene resins, and further, ethylene-propylene copolymer elastomers (EPR), ethylene-butene copolymer elastomers (EBR), ethylene-hexene copolymer elastomers (EHR), ethylene-octene copolymer elastomers (EOR), and other known polyolefin resins such as ethylene-α-olefin copolymer elastomers. Also, the copolymer may be a copolymer composed only of olefins or a copolymer of an olefin and a comonomer that is not an olefin. Among them, preferable examples of the polyolefin resin include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ionomer resin, and the like. However, it is not limited thereto. When the main component resin of the base material layer (I) is a polyolefin resin, it is possible to contain resins other than the polyolefin resin, such as polystyrene resins, polyester resins, and thermoplastic elastomers of the polystyrene type.

[0021] (Other components) The base material layer (I) may also contain components other than the resin, such as additives such as heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, and dyes.

[0022] (Melting point) The melting point of the base layer (I), as measured by DSC measurement, is preferably 50°C or higher, more preferably 80°C or higher, and more preferably 100°C or higher, from the viewpoint of maintaining the pocket shape when used as PTP. On the other hand, from the viewpoint of being easy to mold without requiring high temperatures during molding, it is preferably 200°C or lower, more preferably 180°C or lower, and more preferably 170°C or lower.

[0023] In this invention, the "melting point measured by DSC measurement" is determined by the temperature of the endothermic peak with the greater peak height if two or more endothermic peaks are observed in the DSC curve measured by a differential scanning calorimeter (DSC). The same applies to the melting points of layers other than the base layer (I). Furthermore, if two or more endothermic peaks are observed due to the substrate layer (I) having a multilayer structure, it is preferable that each peak falls within the above range.

[0024] (stretched / unstretched) When the base layer is obtained in film form, the base layer (I) can be an unoriented film, or a uniaxially or biaxially oriented film. Of these, an unoriented film is preferred from the viewpoint of making it easier to open by pressing the pocket portion.

[0025] (Thickness) Preferably, the thickness of the base layer (I) is greater than the thickness of the polyolefin resin layer (III). By having the polyolefin resin (III) thinner than the base layer (I), it is possible to maintain moldability while contributing to the thinning of the overall film. The thickness of the base layer (I) is preferably 100 μm or more from the viewpoint of the sheet's processability and practicality, more preferably 150 μm or more, and more preferably 200 μm or more. On the other hand, from the viewpoint of ease of opening when used as PTP, it is preferably 400 μm or less, more preferably 350 μm or less, and more preferably 300 μm or less.

[0026] (Multi-layer structure) The base layer (I) may be a single layer with a thermoplastic resin as the main component, or a multilayer structure consisting of two or more layers with a thermoplastic resin as the main component. In the case of a multilayer structure, it may consist of multiple layers in which a single thermoplastic resin is the main component resin, or it may consist of multiple layers in which two or more different thermoplastic resins are the main component resins.

[0027] In particular, when the base layer (I) is a layer whose main component is a polyolefin resin, it is preferable from the viewpoint of moldability to have a three-layer structure consisting of a layer whose main component is a polypropylene resin, a layer whose main component is a polyethylene resin, and a layer whose main component is a polypropylene resin.

[0028] Furthermore, in the case of a laminated structure, it may not only be a laminated structure consisting only of virgin layers, but also a laminated structure in which at least one layer is a recycled layer. Here, the virgin layer refers to a layer formed from resin as a virgin material, and refers to a layer formed from resin recycled from waste resin generated during molding. Furthermore, the recycled layer is preferably a repro layer. Here, it is preferable that the repro layer is a layer formed from recycled resin that has been obtained from the burrs generated during the molding of the container.

[0029] <Anchor coat layer (B)> Between the base layer (I) and the polyvinylidene chloride resin layer (II), an anchor coat layer (B) may be interposed as needed, for example, to improve the adhesion between the base layer (I) and the polyvinylidene chloride resin layer (II).

[0030] In particular, when the base layer (I) has a three-layer structure consisting of a layer mainly composed of polypropylene resin, a layer mainly composed of polyethylene resin, and a layer mainly composed of polypropylene resin, it is preferable that the main component resin of the anchor coat layer (B) is a resin obtained by the reaction of a compound containing a hydroxyl group and a compound containing an isocyanate group, from the viewpoint of improving the adhesion between the base layer (I) and the polyvinylidene chloride resin layer (II).

[0031] As the compound containing the hydroxyl group, polyols having two or more hydroxyl groups are preferred. Among these, acrylic polyols, aromatic polyester polyols, aromatic polycarboxylic acids, etc. are preferred in terms of reactivity with isocyanate compounds, and among these, acrylic polyols are preferred because of their excellent transparency.

[0032] On the other hand, the compound containing the isocyanate group is preferably one that acts mainly as a crosslinking agent or curing agent, and should have at least two isocyanate groups (-N=C=O) in its molecule. For example, examples of monomeric isocyanates include aromatic isocyanates such as tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), aliphatic isocyanates such as hexamethylene diisocyanate (HDI), bisisocyanate methylcyclohexane (H6XDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (H12MDI), and aromatic aliphatic isocyanates such as xylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). Polymers or derivatives of these monomeric isocyanates can also be used. Examples of the polymer or derivative include isocyanurate type of trimer, adduct type obtained by reacting with 1,1,1-trimethylolpropane, and biuret type. The isocyanate compound can be arbitrarily selected from the above-mentioned monomer-based isocyanates, their polymers, derivatives, etc., and can be used individually or in combination of two or more types.

[0033] <Polyvinylidene chloride resin layer (II)> The polyvinylidene chloride resin layer (II) is a layer whose main component is polyvinylidene chloride resin. The sheet of the present invention, by comprising a polyvinylidene chloride-based resin layer (II), can have excellent moisture resistance and transparency.

[0034] (Polyvinylidene chloride resin) Examples of polyvinylidene chloride resins include vinylidene chloride polymers, or copolymers of vinylidene chloride monomers with various copolymer monomers. Specific examples of the copolymer monomer include unsaturated carboxylic acids such as vinyl chloride, acrylic acid, methacrylic acid, fumaric acid, and maleic acid; aromatic vinyl compounds such as α-methylstyrene and vinyltoluene; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and hydroxyethyl (meth)acrylate; glycidyl methacrylate ester; and (meth)acrylamides such as (meth)acrylamide and N-methylol(meth)acrylamide. These may be used individually or in combination of two or more.

[0035] The method for producing polyvinylidene chloride resin is not particularly limited. Conventional known methods, such as emulsion polymerization, can be used. Examples of commercially available polyvinylidene chloride resins include the "Saran Latex" series manufactured by Asahi Kasei Corporation.

[0036] The polyvinylidene chloride resin layer (II) may be a single layer consisting of layers with polyvinylidene chloride resin as the main component, or it may be a multi-layer structure comprising two or more layers with polyvinylidene chloride resin as the main component. When multiple polyvinylidene chloride resin layers (II) are laminated, multiple layers may be laminated with a single polyvinylidene chloride resin as the main component resin, or multiple layers may be laminated with two or more different polyvinylidene chloride resins as the main component resin.

[0037] (Other ingredients) The polyvinylidene chloride resin layer (II) may contain resins other than polyvinylidene chloride resins, such as polyolefin resins, polystyrene resins, polyester resins, or polyolefin or polystyrene thermoplastic elastomers. Furthermore, the polyvinylidene chloride resin layer (II) may also contain additives other than resin, such as heat stabilizers, antioxidants, UV absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, and dyes.

[0038] (Melting point) The melting point of the polyvinylidene chloride resin layer (II), as measured by DSC measurement, is preferably 100°C or higher, more preferably 110°C or higher, and more preferably 120°C or higher, from the viewpoint of barrier properties. On the other hand, from the viewpoint of moldability, it is preferably 200°C or lower, more preferably 190°C or lower, and more preferably 180°C or lower.

[0039] The difference between the melting point of the base layer (I) (or, in the case of a multilayer structure, the melting point of the layer located closest to the polyvinylidene chloride resin layer (II)) and the melting point of the polyvinylidene chloride resin layer (II) is preferably 50°C or less, more preferably 40°C or less, and even more preferably 30°C or less, from the viewpoint of preventing cracking of the polyvinylidene chloride resin layer (II) during molding and preventing fusion of the base layer (I) during molding. There is no particular lower limit to the difference in melting points, but it is generally 1°C or more.

[0040] (Thickness) Increasing the thickness of the polyvinylidene chloride resin layer (II) improves moisture resistance, but reduces moldability. Therefore, the thickness of the polyvinylidene chloride resin layer (II) is preferably 1 μm to 150 μm, and more preferably 2 μm or more or 90 μm or less, and more preferably 3 μm or more or 60 μm or less.

[0041] <Anchor coat layer (A)> Between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III), an anchor coat layer (A) may be interposed as needed, for example, to improve the adhesion between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III).

[0042] As described later, when the main component resin of the polyolefin resin layer (III) is a polypropylene copolymer, the main component resin of the anchor coat layer (A) is preferably a polyester resin, a polyurethane resin, or both of these resins, from the viewpoint of improving the adhesion between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III).

[0043] <Polyolefin resin layer (III)> The polyolefin resin layer (III) is a layer whose main component is polyolefin resin. While the polyvinylidene chloride resin layer (II) exhibits excellent water vapor barrier properties, it has poor moldability and slipperiness. Therefore, by laminating a polyolefin resin layer (III) on the back side of the polyvinylidene chloride resin layer (II), moldability and slipperiness can be improved. Thus, for example, when using the sheet of the present invention as a bottom material in PTP, if the polyolefin resin layer (III) is formed on the inner surface of the recess that constitutes the pocket portion, the moldability of the recess can be improved, and the slipperiness of the tablet can be improved.

[0044] (Polyolefin resin) Examples of polyolefin resins that are the main component resin of the polyolefin resin layer (III) include polyethylene resins, polypropylene resins, polybutene resins, poly-4-methylpentene resins, and known polyolefin resins such as ethylene-α-olefin copolymer elastomers, including ethylene-propylene copolymer elastomer (EPR), ethylene-butene copolymer elastomer (EBR), ethylene-hexene copolymer elastomer (EHR), and ethylene-octene copolymer elastomer (EOR). Furthermore, the copolymer may consist only of olefins, or it may be a copolymer of olefins and non-olefin comonomers.

[0045] Among these, a preferred polyolefin resin is a polypropylene copolymer consisting of a copolymer of propylene and other copolymerizable comonomers. Among these, a material mainly composed of propylene copolymerized with a small amount of one or more copolymerizable comonomers is even more preferred. In particular, when forming a polyolefin resin layer (III) by coating, it is preferable that the propylene component is included in a high proportion in order to obtain a high melting point. Specifically, it is preferable that the composition ratio of propylene units be 60% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more. The copolymer of propylene and other copolymerizable comonomers may be a random copolymer or a block copolymer.

[0046] Examples of comonomers that copolymerize with propylene include ethylene and α-olefins having 4 to 20 carbon atoms. Specifically, the following can be listed as α-olefins: 1-butene, 2-methyl-1-propene (all C4); 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene (all C5); 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene (all C6); 1-heptene, 2-methyl-1-hexene, 2,3-dimethyl-1-pentene, 2-ethyl-1-pentene, 2-methyl-3-ethyl-1-butene (all C7); 1-octene, 5-methyl-1-heptene, 2-ethyl-1-butene Examples include 1-Tyl-1-hexene, 3,3-dimethyl-1-hexene, 2-methyl-3-ethyl-1-pentene, 2,3,4-trimethyl-1-pentene, 2-propyl-1-pentene, and 2,3-diethyl-1-butene (all C8); 1-nonene (C9); 1-decene (C10); 1-undecene (C11); 1-dodecene (C12); 1-tridecene (C13); 1-tetradecene (C14); 1-pentadecene (C15); 1-hexadecene (C16); 1-heptadecene (C17); 1-octadecene (C18); and 1-nonadecene (C19).

[0047] Among the above, propylene / ethylene copolymers and propylene / 1-butene copolymers are preferred as polypropylene copolymers. Of these, propylene-ethylene random copolymer (RPP) is particularly preferred. RPP is a random copolymer in which propylene units are 50 mol% or more and ethylene units are 50 mol% or less.

[0048] The most preferred polyolefin resin, which is the main component resin of the polyolefin resin layer (III), is a propylene / ethylene copolymer, that is, a copolymer containing propylene units and ethylene units as monomer components, from the viewpoint of moldability and slipperiness. Among these, from the viewpoint of obtaining a high melting point, it is preferable that the composition ratio of the propylene units is 60% by mass or more, more preferably 75% by mass or more, more preferably 90% by mass or more, and most preferably 95% by mass or more.

[0049] The polyolefin resin, which is the main component resin of the polyolefin resin layer (III), is preferably an acid-modified resin in which an acid component such as maleic anhydride is introduced into the structure while maintaining the melting point within the above range, from the viewpoint of improving adhesion.

[0050] (Other ingredients) The polyolefin resin layer (III) may contain resins other than the polyolefin resin, such as polystyrene resins, polyester resins, or polystyrene-based thermoplastic elastomers. Furthermore, the polyolefin resin layer (III) may also contain additives other than resin, such as heat stabilizers, antioxidants, UV absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, pigments, and dyes.

[0051] (Melting point) The melting point of the polyolefin resin layer (III) in DSC measurement is preferably 130°C or higher. When using the sheet of the present invention as a base material in PTP and arranging it so that the polyolefin resin layer (III) constitutes the inner surface of the recess that forms the pocket portion during PTP molding, the melting point of the polyolefin resin layer (III) is preferably 130°C or higher, more preferably 135°C or higher, more preferably 140°C or higher, and more preferably 145°C or higher. However, if the melting point is too high, a high temperature will be required during PTP molding, which may result in deterioration of the polyvinylidene chloride resin layer (II). Therefore, the melting point is preferably 200°C or lower, more preferably 190°C or lower, and even more preferably 180°C or lower.

[0052] (Coating layer / Laminating layer) The polyolefin resin layer (III) may be formed by coating with a resin composition for forming the polyolefin resin layer (III), or the polyolefin resin layer (III) may be formed by laminating a film made of polyolefin resin layers (III).

[0053] When the polyolefin resin layer (III) is formed by laminating a film, the film may be an unoriented film with the above-mentioned polyolefin resin as the main component, or a uniaxially or biaxially oriented film. In particular, from the viewpoint of improving sealing performance with the lid material, it is preferable to use an unoriented film. For example, unoriented polypropylene (CPP) can be used.

[0054] (Thickness) As mentioned above, from the viewpoint of thinning, it is preferable that the thickness of the polyolefin resin layer (III) is smaller than the thickness of the substrate layer (I). The thickness of the polyolefin resin layer (III) is preferably 0.1 μm to 100 μm from the viewpoint of moldability, processability, and economic efficiency, and more preferably 0.3 μm or more or 70 μm or less, and more preferably 0.5 μm or more or 50 μm or less. When forming by coating with a polyolefin resin layer (III), the thickness of the polyolefin (III) is preferably 0.1 μm to 30 μm, more preferably 0.3 μm or more or 20 μm or less, and more preferably 0.5 μm or more or 10 μm or less. When forming by laminating a polyolefin resin layer (III), the thickness of the polyolefin (III) is preferably 1 μm to 100 μm, more preferably 3 μm or more or 70 μm or less, and more preferably 5 μm or more or 50 μm or less.

[0055] <Thickness of the sheet of this invention> From the viewpoint of processability and moldability, the thickness of the sheet of the present invention is preferably 100 μm to 700 μm, and more preferably 150 μm or more or 500 μm or less, and more preferably 200 μm or more or 400 μm or less.

[0056] From the viewpoint of moisture resistance, the thickness of the polyvinylidene chloride resin layer (II) is preferably 1% or more of the thickness of the base layer (I), more preferably 2% or more, and more preferably 3% or more. On the other hand, from the viewpoint of moldability, the thickness is preferably 70% or less of the thickness of the base layer (I), more preferably 60% or less, and more preferably 50% or less.

[0057] As mentioned above, the thickness of the polyolefin resin layer (III) is preferably less than the thickness of the base layer (I). From this viewpoint, it is preferable that the thickness is 50% or less of the thickness of the base layer (I), more preferably 30% or less, and more preferably 15% or less. On the other hand, from the viewpoint of ensuring moldability, it is preferable that the thickness is 0.1% or more of the thickness of the base layer (I), more preferably 0.2% or more, and more preferably 0.3% or more.

[0058] From the viewpoint of moldability, the thickness of the polyolefin resin layer (III) is preferably 1% or more of the thickness of the polyvinylidene chloride resin layer (II), more preferably 1.5% or more, and more preferably 2% or more. On the other hand, from the viewpoint of processability and economic efficiency, the thickness is preferably 500% or less of the thickness of the polyvinylidene chloride resin layer (II), more preferably 400% or less, and more preferably 300% or less. When formed by coating with a polyolefin resin layer (III), the thickness of the polyolefin (III) is preferably 1% to 100% of the thickness of the polyvinylidene chloride resin layer (II), more preferably 1.5% to 50%, and more preferably 2% to 25%. When forming by laminating a polyolefin resin layer (III), the thickness of the polyolefin (III) is preferably 25% to 500% of the thickness of the polyvinylidene chloride resin layer (II), more preferably 50% to 400%, and more preferably 75% to 300%.

[0059] (Manufacturing method) The method for manufacturing the sheet of the present invention is not particularly limited. For example, each resin composition forming the layers can be prepared separately and then laminated by methods such as coating, co-extrusion, extrusion lamination, heat lamination, or dry lamination. For example, in co-extrusion, the resin compositions forming each layer can be melted and mixed in separate extruders, then laminated and extruded using a feed block or multi-manifold die, and finally rapidly cooled and solidified using a cast roll. In the case of lamination, sheets made of resin compositions that form each layer are stacked and laminated by pressing them together through a heated laminating roll.

[0060] Furthermore, if necessary, the material can be stretched uniaxially or biaxially using methods such as the roll method, tenter method, or tubular method.

[0061] (Applications of the sheet of the present invention) Because the sheet of the present invention has excellent moldability, it can be suitably used, for example, as a base material for PTP. PTP (Press-Through Packaging) is a packaging material consisting of a sheet-like bottom material with recesses (pockets) for inserting tablets or capsules, and a sheet-like lid material that seals these recesses. The tablets or capsules can be removed by pressing the recesses to open the package.

[0062] The bottom material for PTP (Press-Through Packaging) can be made to form recesses that constitute the pocket section. In this case, there are no particular restrictions on the inner diameter and depth of the recess, but for example, the diameter is 5 to 20 mm and the depth is 1 to 10 mm, and a typical example is a diameter of approximately 9 mm and a depth of approximately 4 mm. Furthermore, it is preferable to position and mold the polyolefin resin layer (III) so that it is located on the inside of the recess, that is, on the side that comes into contact with the pharmaceutical product. In other words, it is preferable to position the polyolefin resin layer (III) so that it forms the inner surface of the recess that constitutes the pocket portion.

[0063] A PTP base material formed from the sheet of the present invention and a lid material can be combined to form a PTP.

[0064] As the lid material, conventionally known materials commonly used for PTP (Press-Through Packaging) can be used, such as aluminum foil or film. Furthermore, the contents of the PTP are not particularly limited, as long as they can be stored in the pocket, such as tablets or capsules.

[0065] For example, when manufacturing a bottom material for PTP, the sheet of the present invention can be heated and softened, and then subjected to various molding methods such as plug molding, pressure molding, or vacuum molding. In particular, the sheet of the present invention is especially useful for molding methods using plugs because it has good plug release properties. Among molding methods using plugs, the air-assisted plug molding method, which combines air assistance and plug molding as pre-molding, and the plug compressed air molding method, which assists moldability by raising and lowering the plug at an appropriate timing during compressed air injection, are preferred. Of these, the air-assisted plug molding method is even more preferred from the viewpoint of controlling wall thickness.

[0066] In addition to performing the aforementioned thermoforming, it is also possible to laminate aluminum foil, aluminum vapor-deposited film, plastic film (for example, biaxially oriented polypropylene film, polyamide film, ethylene-vinyl alcohol copolymer film, polyvinylidene chloride film), etc., on the surface, back, or both sides of the sheet. Furthermore, it is also possible to form a composite sheet by laminating aluminum foil or the various films mentioned above on the surface, back, or both sides of the sheet, and then thermoform it.

[0067] Furthermore, to enhance the design and processability of the product, the sheet surface may be subjected to embossing, matting, or other processing. In this case, a mirror-finish sheet may be created first and then processed with an embossing or matting roll, or the cast roll may be changed to an embossing or matting roll during the extrusion molding process. As long as the spirit of the present invention is not impaired, the sheet surface may be coated with an antistatic agent, silicone, wax, etc., or a protective film may be formed using a surface protection sheet for purposes such as preventing scratches, or a printed layer may be provided. Any currently known means can be used to form the printed layer.

[0068] <Explanation of terms> In this specification, when "X~Y" (where X and Y are any numbers) is used, unless otherwise specified, it means "greater than or equal to X and less than or equal to Y," and also includes the meanings of "preferably greater than X" or "preferably less than Y." Furthermore, when we use expressions like "greater than or equal to X" (where X is any number) or "less than or equal to Y" (where Y is any number), we also imply that "greater than X is preferable" or "less than Y is preferable." [Examples]

[0069] The present invention is further illustrated by the following embodiments. These embodiments are not intended to limit the present invention in any way.

[0070] <Raw materials> (Raw material for forming base layer (I)) • Thermoplastic resin substrate: Two types of three-layer structure: "polypropylene layer / polyethylene layer / polypropylene layer", total thickness 250 μm, layer thickness ratio 1:4:1, unstretched film The melting point of the polypropylene layer (a layer whose main component is polypropylene resin) is 160°C. The melting point of the polyethylene layer (a layer whose main component is polyethylene resin) is 127°C.

[0071] (Anchor coat layer (B) forming raw material) Anchor coating agent 1: A coating solution containing acrylic polyol and a trimer of hexamethylene diisocyanate (isocyanurate type) in a mass ratio of 10:1.5.

[0072] (Polyvinylidene chloride resin layer (II) forming raw material) • PVDC latex dispersion: Melting point 131℃, Saran latex L574A (manufactured by Asahi Kasei Corporation)

[0073] (Anchor coat layer (A) forming raw material) • Anchor coating agent 2: A coating liquid whose main component is a saturated copolymer polyester resin consisting of terephthalic acid / isophthalic acid / ethylene glycol / diethylene glycol / neopentyl glycol. • Anchor coating agent 3: A coating liquid whose main component is an aliphatic ester polyol resin.

[0074] (Raw material for forming polyolefin resin layer (III)) • Unoriented polypropylene (CPP) film: 20 μm thick • Polyolefin resin coating agent 1 (PO coating agent 1): A coating liquid whose main component is modified polypropylene resin (mass ratio PP:PE = 98:2). • Polyolefin-based resin coating agent 2 (PO coating agent 2): A coating liquid whose main component is modified polypropylene resin (mass ratio PP:PE = 99:1). • Polyolefin-based resin coating agent 3 (PO coating agent 3): A coating liquid whose main component is polyethylene elastomer. • Polyolefin-based resin coating agent 4 (PO coating agent 4): A coating liquid whose main component is low-density polyethylene (LDPE).

[0075] <Example 1> As the base material (I), the above-mentioned thermoplastic resin base material was used, and the above-mentioned anchor coating agent 1 was applied to one side thereof, dried at 80°C for 1 minute, and an anchor coating layer (B) with a thickness of 1 μm was provided. The PVDC latex dispersion was applied to the anchor coat layer (B), dried at 80°C for 1 minute, and a 10 μm thick polyvinylidene chloride resin layer (II) was formed. The above-mentioned anchor coating agent 2 was applied to the polyvinylidene chloride resin layer (II), dried at 80°C for 1 minute, and an anchor coating layer (A) with a thickness of 1 μm was formed. The above PO coating agent 1 was applied to the anchor coat layer (A), dried at 80°C for 1 minute, and a polyolefin resin layer (III) with a thickness of 1 μm was formed. Through the above operations, a laminated sheet (sample) having the following configuration was obtained: polyolefin resin substrate (I) / anchor coat layer (B) / polyvinylidene chloride resin layer (II) / anchor coat layer (A) / polyolefin resin layer (III). Table 1 shows the melting point of PO coating agent 1 as the melting point of the polyolefin resin layer (III), as well as the coating film evaluation and suitability for molding machine processing for Example 1.

[0076] <Example 2> A laminated sheet (sample) was prepared in the same manner as in Example 1, except that PO coating agent 2 was used instead of PO coating agent 1. Table 1 shows the melting point of PO coating agent 2 as the melting point of the polyolefin resin layer (III), as well as the coating film evaluation and suitability for molding machine processing for Example 2.

[0077] <Example 3> In Example 1, after providing a polyvinylidene chloride resin layer (II), the anchor coating agent 3 was applied to the CPP film and dried at 80°C for 1 minute to provide an anchor coating layer (A) with a thickness of 5 μm. The anchor coat layer (A) and the polyvinylidene chloride resin layer (II) were laminated to create a laminated sheet (sample). Table 1 shows the melting point of the CPP film as the melting point of the polyolefin resin layer (III), and also shows the lamination strength and suitability for molding machine processing for Example 3.

[0078] <Example 4> A laminated sheet (sample) was prepared in the same manner as in Example 1, except that PO coating agent 3 was used instead of PO coating agent 1. Table 1 shows the melting point of PO coating agent 3 as the melting point of the polyolefin resin layer (III), as well as the coating film evaluation and suitability for molding machine processing for Example 4.

[0079] <Example 5> A laminated sheet (sample) was prepared in the same manner as in Example 1, except that PO coating agent 4 was used instead of PO coating agent 1. Table 1 shows the melting point of PO coating agent 4 as the melting point of the polyolefin resin layer (III), as well as the coating film evaluation and suitability for molding machine processing for Example 5.

[0080] <Comparative Example 1> In Example 1, a laminated sheet (sample) was prepared in the same manner as in Example 1, except that the anchor coat layer (A) and the polyolefin resin layer (III) were not provided. Table 1 shows the suitability of Comparative Example 1 for molding machine processing.

[0081] <Measurement and Evaluation Methods> (1) Melting point PO coating agents 1 to 4 were dried at 80°C to obtain solidified products. The obtained solidified products or CPP films were measured using a DSC measuring device (NETZSCH DSC204F1) in accordance with JIS K7121 (2012) under conditions of a measurement temperature range of -50 to 200°C and a heating rate of 10°C / min to determine their melting points.

[0082] (2) Coating film evaluation For PO coating agents 1 to 4 used in the examples and comparative examples, the adhesion between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III) was evaluated using a method compliant with the cross-cut method (grid test method) of JIS K5600-5-6 (1999). Specifically, a utility knife was used to make 11 cuts in the polyolefin resin layer (III) that reached the polyvinylidene chloride resin layer (II), creating 100 grid squares. The cuts were spaced 1 mm apart. Cellophane tape (registered trademark) was pressed onto the grid pattern, and the end of the tape was peeled off at a 45° angle. The number of grid patterns that were peeled off was then counted.

[0083] (3) Lamination strength The laminated sheet (sample) from Example 3 was cut into strips 15 mm wide and 6 cm long, a portion of the end was peeled off, and the laminate strength was measured by peeling the CPP film 180° using a tensile testing machine (STA-1150, manufactured by Orientec Co., Ltd.) at a speed of 300 mm / min.

[0084] (4) Suitability for molding machine processing Using a PTP molding machine (FBP-300E (manufactured by CKD Corporation)), the laminated sheets (samples) prepared in the examples and comparative examples were subjected to PTP molding by the air-assisted plug molding method. Specifically, after heating and softening the laminated sheets (samples) prepared in the examples and comparative examples, they were placed between an upper and lower mold, and heated and molded under the conditions of a sheet heating temperature of 126°C, a pocket size of Φ10 mm, and a depth of 4.5 mm, so that the polyolefin resin layer (III) was on the inside of the recesses, thereby forming multiple recesses within the sheet surface. Subsequently, a 20 μm thick aluminum foil was sealed onto the sheet surface where the recesses were formed to create a press-through package.

[0085] The following criteria were used for evaluation. "○"...The molding process was carried out smoothly without any problems, and the appearance of the finished press-through package was also good. "△" ...After molding, when separating the convex-shaped plug from the recess, slight marks from the plug remained on the sheet surface, but the recess was formed normally, and there are no practical problems. "×"...During the molding process, the bottom edge of the recess became concave, or the recess fused to the plug and was pulled and deformed when the plug was removed, resulting in a failure to form a normal recess, and problems with the shape of the finished press-through package molded product.

[0086] [Table 1]

[0087] (Results / Discussion) From the results of the above embodiments, as well as from the test results conducted by the present invention to date, it has been found that because the polyvinylidene chloride resin layer (II) is sandwiched between the base layer (I) and the polyolefin resin layer (III), moldability can be improved, and even small-diameter recesses, such as the pocket portion in the bottom material of PTP, can be suitably molded. Furthermore, it was found that by raising the melting point of the polyolefin resin layer (III) to 130°C or higher in DSC measurements, the PTP moldability can be improved. For example, when pressing with a plug to form a recess in the pocket portion, it is possible to improve the release properties from the plug and suppress the indentation of the bottom surface of the recess. Furthermore, the results of the coating film evaluation or laminate strength in Examples 1 to 5 showed that there were no practical problems with the adhesion between the polyvinylidene chloride layer (II) and the polyolefin resin layer (III).

Claims

1. The base material for press-through packaging comprises a base layer (I) mainly composed of a thermoplastic resin, a polyvinylidene chloride resin layer (II) mainly composed of a polyvinylidene chloride resin, and a polyolefin resin layer (III) mainly composed of a polyolefin resin, laminated in this order, wherein the thickness of the base layer (I) is greater than the thickness of the polyolefin resin layer (III), the base layer (I) has a three-layer structure consisting of a layer mainly composed of a polypropylene resin, a layer mainly composed of a polyethylene resin, and a layer mainly composed of a polypropylene resin, the melting point of the polyolefin resin layer (III) in DSC measurement is 130°C or higher, and the polyolefin resin layer (III) is arranged to form the inner surface of the recess that constitutes the pocket portion.

2. The bottom material for press-through packaging according to claim 1, comprising an anchor coat layer (A) between the polyvinylidene chloride resin layer (II) and the polyolefin resin layer (III).

3. The bottom material for press-through packaging according to claim 2, wherein the main component resin of the anchor coat layer (A) is a polyester resin, a polyurethane resin, or both of these resins.

4. The bottom material for press-through packaging according to any one of claims 1 to 3, wherein the polyolefin resin, which is the main component resin of the polyolefin resin layer (III), contains propylene units and ethylene units as monomer components, and the composition ratio of the propylene units is 60% by mass or more.

5. The bottom material for press-through packaging according to any one of claims 1 to 4, wherein the polyolefin resin layer (III) is a layer formed by coating.

6. The bottom material for press-through packaging according to any one of claims 1 to 4, wherein the polyolefin resin layer (III) is a layer formed by laminating a film.

7. The bottom material for press-through packaging according to claim 6, wherein the thickness of the polyolefin resin layer (III) is greater than 5 μm and 50 μm or less.

8. The bottom material for press-through packaging according to any one of claims 1 to 7, comprising an anchor coat layer (B) between the base material layer (I) and the polyvinylidene chloride resin layer (II).

9. The bottom material for press-through packaging according to claim 8, wherein the main component resin of the anchor coat layer (B) is a resin obtained by the reaction of a compound containing a hydroxyl group and a compound containing an isocyanate group.

10. A press-through package comprising a bottom material for press-through packaging and a lid material according to any one of claims 1 to 9.

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